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Sample records for suspected epidemic keratoconjunctivitis

  1. An outbreak of epidemic keratoconjunctivitis at an outpatient ophthalmology clinic

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    Timothy J Doyle

    2010-12-01

    Full Text Available Epidemic keratoconjunctivitis (EKC is an acute eye infection caused by adenovirus. We investigated an outbreak of EKC at an outpatient ophthalmology practice in the context of a suspected community wide increase in EKC activity. A site visit was made to the facility reporting the outbreak. A line list was created of patients clinically diagnosed with EKC at the practice during the previous 5 months. A questionnaire was faxed to all other licensed ophthalmologists in the county regarding recent EKC activity in their facility. Descriptive data analyses were conducted. The outbreak facility reported 37 patients clinically diagnosed with EKC during the previous 5 months. In addition, the single ophthalmologist at the practice also had symptoms compatible with EKC during the outbreak period. Specimens were collected on 4 patients and all were positive for adenovirus serotype 8. Forty percent of ophthalmologists surveyed in the county saw at least one EKC patient in the previous 3 months, and 20% reported a perceived increase in EKC activity in recent months over normal seasonal patterns. The outbreak at the facility likely began as part of a widespread community increase in EKC that may have been amplified at the facility through nosocomial transmission. Medical providers experiencing increases in EKC activity above seasonally expected norms should contact their public health department for assistance with etiologic diagnoses and outbreak control.

  2. Outbreak of epidemic keratoconjunctivitis caused by adenovirus in medical residents.

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    Melendez, Carlos Pantoja; Florentino, Margarita Matias; Martinez, Irma Lopez; Lopez, Herlinda Mejia

    2009-01-01

    The present work documents an outbreak of epidemic keratoconjunctivitis among ophthalmology residents, its influence in the presentation of the community cases, the use of molecular techniques for its diagnosis, and the implementation of successful control measures for its containment. Isolation of the etiologic agent was achieved using cultured African green monkey kidney epithelial cells (VERO). Through molecular tests, such as polymerase chain reaction (PCR) and DNA sequencing, the genotype of the isolated virus was identified. The sequences obtained were aligned with data reported in the NCBI GenBank. A scheme of outbreak control measures was designed to enforce correct sanitary measures in the clinic. The statistical program, Epi info 2002, and openepi were used to determine the attack rate. The Excel Microsoft program was used to elaborate the endemic channel. Nine of the ten samples studied were isolated from the culture and identified by Adenovirus-specifc PCR. Sequencing allowed identification of Ad8 as the agent responsible for the outbreak. The attack rate was 24.39 cases per 100. The epidemic curve allowed identification of a disseminated source in the Institute of Ophthalmology "Conde de Valenciana." It was not possible to calculate the incubation periods among the cases. The endemic channel showed the presence of an epidemic keratoconjunctivitis among the patients that had been cared for at the out-patient services of the institute. One outbreak of a disseminated source caused by Ad8 was detected in the institute among its medical residents, probably associated with relaxation of the habitual sanitary measures during an epidemic of hemorrhagic conjunctivitis among the patients cared for at the institute. The proposed scheme to control the outbreak allowed for its containment and controlled the epidemic of associated cases.

  3. [Local cyclosporin A therapy of nummuli after epidemic keratoconjunctivitis--case report].

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    Reinhard, T; Sundmacher, R

    1997-03-01

    Steroid therapy for persistent or recurrent nummular adenoviral keratoconjunctivitis (AK) has little benefit because of the frequent recurrences, and mostly "offers" only serious steroid side effects. Since January 1995, we have treated different patients with nummuli after AK with topical Ciclosporin A (CSA) in an attempt to achieve at least the same symptomatic effect as with steroids, however, without side effects. Here, we report about our experiences in a very severe case with longterm treatment. The patient was sent to our clinic 4 months after AK with confluent nummuli and Descemet folds, more severe in the right than in the left eye. Best corrected visual acuity was 0.05 in the right and 0.5 in the left eye. Topical CSA 2% 4 times daily was first administered only in the right eye. When after 6 weeks a reduction of nummuli was noted in the right eye, the left eye, which had not improved, was started on the same regime. Therapy was tapered and finally stopped after 12 months in the right and 10 months in the left eye, when only minor changes were left in the corneae. A prompt recurrence of nummuli in both eyes within 4 weeks forced us to resume CSA therapy. At present, both corneae are clear with full vision, and this result is stable with 1 drop of CSA daily. No side effects of CSA therapy have been noted. The disappearance of nummuli with topical CSA and even more the reappearance of nummuli after cessation of CSA therapy show that topical CSA is about as effective as topical steroids in the symptomatic treatment of non-scarred nummuli after KE without the serious steroid side effects. Topical CSA treatment of nummuli after KE is, therefore, a very recommendable alternative for the potentially dangerous steroid therapy. Generally valid data on risk of recurrences, dosage and general effectiveness could only be learned from prospective studies with large numbers of AK patients, which, however, are not available outside epidemics.

  4. Evidence of molecular evolution driven by recombination events influencing tropism in a novel human adenovirus that causes epidemic keratoconjunctivitis.

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    Michael P Walsh

    2009-06-01

    Full Text Available In 2005, a human adenovirus strain (formerly known as HAdV-D22/H8 but renamed here HAdV-D53 was isolated from an outbreak of epidemic keratoconjunctititis (EKC, a disease that is usually caused by HAdV-D8, -D19, or -D37, not HAdV-D22. To date, a complete change of tropism compared to the prototype has never been observed, although apparent recombinant strains of other viruses from species Human adenovirus D (HAdV-D have been described. The complete genome of HAdV-D53 was sequenced to elucidate recombination events that lead to the emergence of a viable and highly virulent virus with a modified tropism. Bioinformatic and phylogenetic analyses of this genome demonstrate that this adenovirus is a recombinant of HAdV-D8 (including the fiber gene encoding the primary cellular receptor binding site, HAdV-D22, (the epsilon determinant of the hexon gene, HAdV-D37 (including the penton base gene encoding the secondary cellular receptor binding site, and at least one unknown or unsequenced HAdV-D strain. Bootscanning analysis of the complete genomic sequence of this novel adenovirus, which we have re-named HAdV-D53, indicated at least five recombination events between the aforementioned adenoviruses. Intrahexon recombination sites perfectly framed the epsilon neutralization determinant that was almost identical to the HAdV-D22 prototype. Additional bootscan analysis of all HAdV-D hexon genes revealed recombinations in identical locations in several other adenoviruses. In addition, HAdV-D53 but not HAdV-D22 induced corneal inflammation in a mouse model. Serological analysis confirmed previous results and demonstrated that HAdV-D53 has a neutralization profile representative of the epsilon determinant of its hexon (HAdV-D22 and the fiber (HAdV-D8 proteins. Our recombinant hexon sequence is almost identical to the hexon sequences of the HAdV-D strain causing EKC outbreaks in Japan, suggesting that HAdV-D53 is pandemic as an emerging EKC agent. This documents

  5. Sensitivity and Specificity of Suspected Case Definition Used during West Africa Ebola Epidemic.

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    Hsu, Christopher H; Champaloux, Steven W; Keïta, Sakoba; Martel, Lise; Bilivogui, Pepe; Knust, Barbara; McCollum, Andrea M

    2018-01-01

    Rapid early detection and control of Ebola virus disease (EVD) is contingent on accurate case definitions. Using an epidemic surveillance dataset from Guinea, we analyzed an EVD case definition developed by the World Health Organization (WHO) and used in Guinea. We used the surveillance dataset (March-October 2014; n = 2,847 persons) to identify patients who satisfied or did not satisfy case definition criteria. Laboratory confirmation determined cases from noncases, and we calculated sensitivity, specificity and predictive values. The sensitivity of the defintion was 68.9%, and the specificity of the definition was 49.6%. The presence of epidemiologic risk factors (i.e., recent contact with a known or suspected EVD case-patient) had the highest sensitivity (74.7%), and unexplained deaths had the highest specificity (92.8%). Results for case definition analyses were statistically significant (pdefinition used in Guinea contributed to improved overall sensitivity and specificity.

  6. Molecular epidemiology of adenoviral keratoconjunctivitis in Saudi Arabia.

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    Tabbara, Khalid F; Omar, Nazri; Hammouda, Ehab; Akanuma, Masataka; Ohguchi, Takeshi; Ariga, Toshihide; Tagawa, Yoshitsugu; Kitaichi, Nobuyoshi; Ishida, Susumu; Aoki, Koki; Ishiko, Hiroaki; Ohno, Shigeaki

    2010-10-24

    Adenoviral keratoconjunctivitis is a major cause of ocular morbidity and may lead to visual loss. Adenovirus types 8, 19, and 37 may cause epidemic keratoconjunctivitis. The main objective of this study was to determine the types of adenoviruses causing keratoconjunctivitis in Saudi Arabia. We conducted a non-interventional observational clinical study. Seventy three eyes from 65 patients who presented to The Eye Center in Riyadh, Saudi Arabia with clinical features of acute adenoviral keratoconjunctivitis were included. Each patient underwent complete clinical examination and features such as membranous reaction, conjunctival hemorrhage, subepithelial corneal infiltrates, and preauricular lymph node enlargement were recorded. Conjunctival swabs were obtained from patients with presumed acute viral conjunctivitis. Immunochromatography (IC) and restriction fragment length polymorphism polymerase chain reaction (PCR-RFLP) were performed on the conjunctival swabs obtained from each eye. Serotype identification was performed using direct sequencing technique. Forty-nine (67.1%) were adenovirus type 8, 8 (11.0%) were adenovirus type 3, 6 (8.2%) type 37, 5 (6.8%) were adenovirus type 4, and 2 (2.3%) type 19. The remaining 5 were types 14, 19, and 22. The prevalence of membranous conjunctivitis was highest (83%) among eyes with adenovirus type 37 while subepithelial corneal opacities were most commonly seen among eyes with adenovirus type 8 (47%). Immunochromatography tests were positive for adenovirus in 48 (65.7%) out of 73 eyes. This study determined the types of adenoviruses causing keratoconjunctivitis at one center in Saudi Arabia. Direct sequencing techniques is an efficient, accurate, and rapid means of diagnosing adenoviral keratoconjunctivitis. The most common causes of adenoviral keratoconjunctivitis in Saudi Arabia were adenovirus types 8, 3, and 37. Membranous conjunctivitis and subepithelial opacities had the highest frequency of adenovirus types 37 and 8

  7. Listeria monocytogenes endophthalmitis following keratoconjunctivitis.

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    Shoughy, Samir S; Tabbara, Khalid F

    2014-01-01

    Endophthalmitis due to endogenous or exogenous bacteria is a rare infection of the eye. We report a case of endophthalmitis following Listeria monocytogenes keratoconjunctivitis in a 27-year-old healthy white male presenting with hand motion visual acuity, right eye mucopurulent conjunctivitis, elevated intraocular pressure, and pigmented hypopyon 6 months post-keratectomy. The conjunctivitis was unresponsive to a 5-day course of topical tobramycin eye drops, and the patient developed keratitis with pain that progressed to endophthalmitis after 21 days. Diagnostic B-scan revealed vitreous exudates. Intraocular fluid specimen showed Gram-positive organisms and the aqueous culture grew penicillin-/aminoglycoside-sensitive L. monocytogenes. The patient was given intravitreal and systemic vancomycin and ceftazidime. The eye was unresponsive to intravenous penicillin and gentamicin; the anterior chamber progressively flattened and developed phthisis bulbi. L. monocytogenes keratoconjunctivitis may lead to bacterial endophthalmitis. Prompt culture and early antibiotic therapy are recommended.

  8. Listeria monocytogenes endophthalmitis following keratoconjunctivitis

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    Shoughy SS

    2014-01-01

    Full Text Available Samir S Shoughy,1 Khalid F Tabbara1–31The Eye Center and The Eye Foundation for Research in Ophthalmology, Riyadh, Saudi Arabia; 2Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia; 3The Wilmer Ophthalmological Institute of The Johns Hopkins University School of Medicine, Baltimore, MD, USAAbstract: Endophthalmitis due to endogenous or exogenous bacteria is a rare infection of the eye. We report a case of endophthalmitis following Listeria monocytogenes keratoconjunctivitis in a 27-year-old healthy white male presenting with hand motion visual acuity, right eye mucopurulent conjunctivitis, elevated intraocular pressure, and pigmented hypopyon 6 months post-keratectomy. The conjunctivitis was unresponsive to a 5-day course of topical tobramycin eye drops, and the patient developed keratitis with pain that progressed to endophthalmitis after 21 days. Diagnostic B-scan revealed vitreous exudates. Intraocular fluid specimen showed Gram-positive organisms and the aqueous culture grew penicillin-/aminoglycoside-sensitive L. monocytogenes. The patient was given intravitreal and systemic vancomycin and ceftazidime. The eye was unresponsive to intravenous penicillin and gentamicin; the anterior chamber progressively flattened and developed phthisis bulbi. L. monocytogenes keratoconjunctivitis may lead to bacterial endophthalmitis. Prompt culture and early antibiotic therapy are recommended.Keywords: conjunctivitis, L. monocytogenes, endophthalmitis

  9. Medicamentosa keratoconjunctivitis: A case report

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    Chiemela C. Okoro

    2016-03-01

    Full Text Available We present a case of medicamentosa keratoconjunctivitis in a 42-year-old woman who complained of eye redness, blurred vision and pain after using inappropriate medications for treatment. Examination revealed severe conjunctival injection as well as punctate stains on the corneas. The patient was advised to stop her former medications and was prescribed an artificial tear supplement, an antibiotic-steroid combination and a topical nonsteroidal anti-inflammatory drug. Possible conditions that could elicit similar clinical features are highlighted. The purpose of the case report is to raise issues relating to drug-induced allergic/sensitivity reactions based on recent clinical and experimental reports and also the roles of active ingredients and preservatives. Keywords: Superficial punctate epitheliopathy; Medicamentosa; Factitious disease; Dry eye syndrome; Benzalkonium chloride

  10. uv keratoconjunctivitis vs. established dose effect relationships

    International Nuclear Information System (INIS)

    Gulvady, N.U.

    1976-01-01

    A patient who received a uv dose to his eyes 11 times greater than the photokeratitic threshold of Pitts and 4 1 / 2 times the photokeratitic threshold as found by Leach. The patient had severe keratoconjunctivitis for 3 days and did not develop any keratitis

  11. Topical cyclosporine for atopic keratoconjunctivitis.

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    González-López, Julio J; López-Alcalde, Jesús; Morcillo Laiz, Rafael; Fernández Buenaga, Roberto; Rebolleda Fernández, Gema

    2012-09-12

    Atopic keratoconjunctivitis (AKC) is a chronic ocular surface non-infectious inflammatory condition that atopic dermatitis patients may suffer at any time point in the course of their dermatologic disease and is independent of its degree of severity. AKC is usually not self resolving and it poses a higher risk of corneal injuries and severe sequelae. Management of AKC should prevent or treat corneal damage. Although topical corticosteroids remain the standard treatment for patients with AKC, prolonged use may lead to complications. Topical cyclosporine A (CsA) may improve AKC signs and symptoms, and be used as a corticosteroid sparing agent. To determine the efficacy and gather evidence on safety from randomised controlled trials (RCTs) of topical CsA in patients with AKC. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 6), MEDLINE (January 1946 to July 2012), EMBASE (January 1980 to July 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to July 2012), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (January 1937 to July 2012), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en), the IFPMA Clinical Trials Portal (http://clinicaltrials.ifpma.org/no_cache/en/myportal/index.htm) and Web of Science Conference Proceedings Citation Index- Science (CPCI-S). We did not use any date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 9 July 2012. We also handsearched the following conference proceedings: American Academy of Ophthalmology, Association for Research in Vision and Ophthalmology, International Council of Opthalmology and Societas

  12. BILATERAL STEROID INDUCED GLAUCOMA IN VERNAL KERATOCONJUNCTIVITIS

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    Bangal Surekha V, Bankar Mahima S, Bhandari Akshay J, Kalkote Prasad R

    2015-01-01

    Full Text Available Vernal Keratoconjunctivits (VKC is a bilateral recurrent allergic interstitial conjunctival inflammation with a periodic seasonal incidence and of self limiting nature, mainly affecting the younger population. Patients of VKC on steroid therapy are at higher risk of developing steroid induced glaucoma. Raised intraocular pressure due to steroids typically occurs within few weeks of starting steroid therapy and comes back to normal on immediate stoppage of steroids. A case of steroid induced glaucoma in a 30 years old female with vernal keratoconjunctivitis. She was on topical steroids for 3-4 years. She was incompliant with the instructions to stop steroids. She eventually developed steroid induced glaucoma and glaucomatous optic neuropathy with tunnel vision.

  13. Liquid nitrogen cryotherapy of superior limbic keratoconjunctivitis.

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    Fraunfelder, Frederick W

    2009-02-01

    To evaluate the effects of liquid nitrogen cryotherapy on superior limbic keratoconjunctivitis (SLK). Interventional case series. In this clinical practice case series, the effects of liquid nitrogen cryotherapy on SLK were observed. Liquid nitrogen cryotherapy was performed using a Brymill E tip spray (0.013-inch aperture) with a double freeze-thaw technique. All subjects were outpatients who had local anesthesia with a single drop of topical proparacaine. The main outcome measure was the resolution of the disease process after treatment. Four female patients (average age, 64 +/- 13 years) and seven eyes with SLK were treated with liquid nitrogen cryotherapy. Resolution of signs and symptoms occurred within two weeks. Disease recurred in two patients and three of seven eyes, although repeat cryotherapy eradicated SLK in all cases. The repeat cryotherapy was performed at three months postoperatively. There were no adverse ocular events. Liquid nitrogen cryotherapy appears to be an effective alternative treatment for SLK as all subjects studied achieved long-term cures. Repeat cryotherapy may be necessary in some instances and may be performed three months after the first treatment.

  14. Tear ferning in normal dogs and dogs with keratoconjunctivitis sicca ...

    African Journals Online (AJOL)

    This study evaluates tear ferning as an ancillary technique for the evaluation of the canine tear film in normal eyes and eyes affected by keratoconjunctivitis sicca (KCS). Thirty dogs with KCS and 50 control dogs with normal tear film were evaluated with a full ophthalmoscopic examination and a Schirmer tear test type 1 ...

  15. Oral cyclosporine therapy for refractory severe vernal keratoconjunctivitis

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    Nikhil S Gokhale

    2012-01-01

    Full Text Available We report the success of oral cyclosporine therapy in a patient with severe vision-threatening vernal keratoconjunctivitis. A child presented with severe allergy which was not controlled with topical steroids, cyclosporine and mast cell stabilizers. Oral steroids were required repeatedly to suppress inflammation. Child showed a dramatic improvement and stabilization with oral cyclosporine therapy. Oral cyclosporine therapy can be tried in severe vision-threatening allergy refractory to conventional therapy.

  16. Primary Sjögren's syndrome and keratoconjunctivitis sicca: Diagnostic methods, frequency and social disease aspects

    DEFF Research Database (Denmark)

    Bjerrum, Kirsten Birgitte

    ophthalmology, Sjögren's syndrome, keratoconjunctivitis sicca, conjunctiva, dry eye, Schirmer-1 test, Rose Bengal score, break-up time, tear film, Copenhagen criteria......ophthalmology, Sjögren's syndrome, keratoconjunctivitis sicca, conjunctiva, dry eye, Schirmer-1 test, Rose Bengal score, break-up time, tear film, Copenhagen criteria...

  17. Acquisition of vernal and atopic keratoconjunctivitis after bone marrow transplantation.

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    Tabbara, Khalid F; Nassar, Amr; Ahmed, Syed Osman; Al Mohareb, Fahad; Aljurf, Mahmoud

    2008-09-01

    Vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC) result from genetic and environmental factors. We present patients who had no history of atopic disorders before bone marrow transplantation (BMT) and who seem to have acquired VKC or AKC from their donors, who had atopic disorders. Observational case series. The patients in this study were part of a cohort of patients who had undergone allogeneic hemapoietic stem cell transplantation (HSCT) from January 1997 through December 2007. Of 621 HSCT recipients, four recipients who were free of allergic disorders acquired VKC or AKC from their afflicted donors after HSCT. Each patient underwent complete ophthalmologic examination, determination of the total serum immunoglobulin (Ig) E, and conjunctival scrapings. Four (0.64%) of 621 patients who had undergone HSCT acquired VKC or AKC after BMT. The donors had VKC or atopic dermatitis. In addition, in two of these four patients, asthma developed. One patient had elevated total serum IgE. Conjunctival scrapings of all four patients revealed the presence of eosinophils. One patient had concurrent graft-versus-host disease. VKC and AKC are systemic allergic disorders characterized by local ocular manifestations. This report suggests the possibility of the acquisition of VKC or AKC after BMT by adoptive transfer.

  18. Supratarsal injection of triamcinolone for severe vernal keratoconjunctivitis in children

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    Alexandre Xavier da Costa

    Full Text Available ABSTRACT Purpose: To evaluate the use of supratarsal injection of triamcinolone acetonide in severe vernal keratoconjunctivitis (VKC in children. Methods: Patients included in this open clinical trial were those with severe VKC-associated with keratitis, gelatinous limbal infiltrates, and/or giant papillae, with a history of recurrence and resistance to conventional topical antiallergic agents. Patients were treated with a supratarsal injection of 20 mg triamcinolone acetonide. Results: Analysis included 27 injections in 23 eyes of 17 patients with severe allergic keratoconjunctivitis. Mean age was 12.3 (range: 7-19 years. Mean follow-up time was 39.3 months (SD=19.21. In the 17 patients, the disease was successfully controlled for an average of 3.6 months (range: 1-16, during which allergy symptoms and signs were significantly improved, with complete resolution of lid edema and conjunctival chemosis, significant decline of pannus and keratitis, and reduction of giant papillae size. Conclusion: Treatment of severe, acute VKC in children with supratarsal injection of 20 mg triamcinolone acetonide showed satisfactory results and was well tolerated by patients; it may therefore constitute a safe option for severe and challenging cases. While full disease remission was not achieved, a significant improvement was found in ocular allergy symptoms and signs, with a reduction in the frequency of acute recurrences.

  19. Corneal complications and visual impairment in vernal keratoconjunctivitis patients

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    Arif, A.S.; Aaqil, B.; Siddiqui, A.; Nazneen, Z.; Farooq, U.

    2017-01-01

    Vernal kerato-conjunctivitis (VKC) is an infrequent but serious form of allergic conjunctivitis common in warm and humid areas where air is rich in allergens. It affects both eyes asymmetrically. Although VKC is a self-limiting disease but visions affecting corneal complications influence the quality of life in school children. The aim of this study was to list the corneal complications due to this condition and to find out the extent of visual impairment among VKC patients. Methods: This cross-sectional study was conducted in the department of Ophthalmology, Benazir Bhutto Shaheed Hospital on 290 eyes of diagnosed cases of VKC. The diagnosis of VKC was made on the basis of history and examination. Visual acuity was recorded using Snellen's notation and visual impairment was classified according to World Health Organization classification for visual disabilities. Results: The mean age of presentation was 10.83+-6.13 years. There were 207 (71.4%) males and 83 (28.6%) females. Corneal scarring was observed in 59 (20.3%) eyes. Keratoconus was found to be in 17 (5.9%) eyes. Shield ulcer was detected in 09 (3.1%) eyes while 07 (2.4%) eyes had corneal neovascularization. Majority of the patients with visual loss had corneal scarring and the complication that led to severe visual loss in most of the eyes was Keratoconus. Conclusion: Vernal kerato-conjunctivitis in the presence of corneal complications is a sight threatening disease and can lead to severe visual impairment. (author)

  20. Spooky Suspects

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    Pacifici, Lara

    2011-01-01

    This activity presents an option for covering biology content while engaging students in an investigation that highlights the spirit of Halloween. Students are engaged in the story line and have fun trying to solve the mystery kidnapping by using science skills to examine the evidence and eliminate some ghoulish suspects. (Contains 1 figure.)

  1. Detection of equine herpesvirus in horses with idiopathic keratoconjunctivitis and comparison of three sampling techniques.

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    Hollingsworth, Steven R; Pusterla, Nicola; Kass, Philip H; Good, Kathryn L; Brault, Stephanie A; Maggs, David J

    2015-09-01

    To determine the role of equine herpesvirus (EHV) in idiopathic keratoconjunctivitis in horses and to determine whether sample collection method affects detection of EHV DNA by quantitative polymerase chain reaction (qPCR). Twelve horses with idiopathic keratoconjunctivitis and six horses without signs of ophthalmic disease. Conjunctival swabs, corneal scrapings, and conjunctival biopsies were collected from 18 horses: 12 clinical cases with idiopathic keratoconjunctivitis and six euthanized controls. In horses with both eyes involved, the samples were taken from the eye judged to be more severely affected. Samples were tested with qPCR for EHV-1, EHV-2, EHV-4, and EHV-5 DNA. Quantity of EHV DNA and viral replicative activity were compared between the two populations and among the different sampling techniques; relative sensitivities of the sampling techniques were determined. Prevalence of EHV DNA as assessed by qPCR did not differ significantly between control horses and those with idiopathic keratoconjunctivitis. Sampling by conjunctival swab was more likely to yield viral DNA as assessed by qPCR than was conjunctival biopsy. EHV-1 and EHV-4 DNA were not detected in either normal or IKC-affected horses; EHV-2 DNA was detected in two of 12 affected horses but not in normal horses. EHV-5 DNA was commonly found in ophthalmically normal horses and horses with idiopathic keratoconjunctivitis. Because EHV-5 DNA was commonly found in control horses and in horses with idiopathic keratoconjunctivitis, qPCR was not useful for the etiological diagnosis of equine keratoconjunctivitis. Conjunctival swabs were significantly better at obtaining viral DNA samples than conjunctival biopsy in horses in which EHV-5 DNA was found. © 2015 American College of Veterinary Ophthalmologists.

  2. Effect of Topical Cyclosporine in grading of Vernal keratoconjunctivitis.

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    Dr Krupali Raol

    2017-06-01

    Full Text Available Background & Objective: To evaluate efficacy of topical aqueous solution of 0.05% cyclosporine in first time diagnosed vernal keratoconjunctivitis (VKC including palpebral, bulbar and mixed form. Methods: 25 patients of VKC received CsA 0.05% aqueous ophthalmic solution in a dosage of one drop every 12 hours in both eyes for 6 months. Follow up visits (day 1, 2 weeks, 1 month, 2 months, 3 months and 6 months. Five symptoms were evaluated and six clinical signs were charted. Total objective score of 13 or more over atleast 3 variables was included (CART – scoring system. Results: Comparison of 1st Day with 2 weeks score showed no significant effect in the score value (t=0.90, df = 24, p<0.1. 1st Day with 3rd month score showed maximum effect in the score value (t = 35.76, df = 24, p<0.0001. 3rd month with 6th month score showed sustained effect of cyclosporine showing no major change in the score line (t test, t = 1.80, df = 24, p <0.05. Conclusion: Topical application of a 0.05% CsA aqueous solution has been shown to be effective in the treatment of patients with VKC. CsA could be an important alternative to steroid treatment.

  3. A simplified quantitative method for assessing keratoconjunctivitis sicca from the Sjögren's Syndrome International Registry

    DEFF Research Database (Denmark)

    Whitcher, John P; Shiboski, Caroline H; Shiboski, Stephen C

    2010-01-01

    To describe, apply, and test a new ocular grading system for assessing keratoconjunctivitis sicca (KCS) using lissamine green and fluorescein.......To describe, apply, and test a new ocular grading system for assessing keratoconjunctivitis sicca (KCS) using lissamine green and fluorescein....

  4. Topical tacrolimus for the treatment of severe allergic keratoconjunctivitis in children

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    Vera Lucia Liendo

    Full Text Available ABSTRACT Purpose: Administration of eye drops containing antihistamines or sodium cromoglycate and its derivatives for the treatment of allergic keratoconjunctivitis is often insufficient and usually requires the addition of corticosteroids. However, the risk of complications, such as glaucoma and cataract, limits the use of corticosteroids to short courses, resulting in inadequate long-term treatment response. Immunosuppressive drugs have been considered as a valid alternative to steroids for atopic keratoconjunctivitis and vernal keratoconjunctivitis. This study aimed to evaluate the use of topical tacrolimus (TCL in improving the clinical signs of severe allergic keratoconjuctivitis in children. Methods: Patients with severe allergic keratoconjunctivitis associated with corneal epitheliopathy, gelatinous limbal infiltrates, and/or papillary reaction, along with a history of recurrences and resistance to conventional topical anti-allergy agents, were included in this open clinical trial. Patients were treated with 0.03% TCL ointment for ocular use. A severity score ranging from 0 to 9, with 9 being the highest and 0 being the lowest, was assigned based on signs observed on biomicroscopy prior to and following TCL treatment. Results: Analyses included 66 eyes of 33 patients. After a mean follow-up period of 13 months (range, 12-29 months, TCL treatment significantly decreased the mean symptom score severity for the right (from 5.56 ± 1.18 to 2.76 ± 1.5; p<0.001 and left (from 5.94 ± 1.16 to 2.86 ± 1.64; p<0.001. Conclusion: Topical TCL was effective and significantly improved the clinical signs of allergic keratoconjuctivitis in children. Thus, it is a potential new option for severe and challenging cases of ocular allergy.

  5. Listeria monocytogenes associated kerato-conjunctivitis in four horses in Norway.

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    Revold, Tobias; Abayneh, Takele; Brun-Hansen, Hege; Kleppe, Signe L; Ropstad, Ernst-Otto; Hellings, Robert A; Sørum, Henning

    2015-11-09

    Listeria monocytogenes has been reported to cause various infectious diseases in both humans and animals. More rarely, ocular infections have been reported. To our knowledge, only two cases of Listeria keratitis have been described in horses. We report kerato-conjunctivitis in four Norwegian horses associated with L. monocytogenes. Clinically, all cases were presented with recurrent unilateral kerato-conjunctivitis. L. monocytogenes bacteria were isolated from swab samples from all cases, and cytology carried out in 3 cases was indicative of L. monocytogenes infection. The present report describes the first known cases in which L. monocytogenes has been isolated from keratitic lesions in horses in Norway. A potential risk factor may be feeding of silage or haylage, but other sources of infection cannot be ruled out. The phenotypic features including antimicrobial susceptibility and serotype of the isolates are described. Laboratory detection of L. monocytogenes demands extra caution since only low numbers of bacteria were detected in the eye-swabs, probably due to the low volume of sample material and the intracellular niche of the bacterium. A general poor response to treatment in all these cases indicates that clinicians should pay extra attention to intensity and duration of treatment if L. monocytogenes is identified in connection with equine kerato-conjunctivitis.

  6. Epidemic typhus.

    Science.gov (United States)

    Bechah, Yassina; Capo, Christian; Mege, Jean-Louis; Raoult, Didier

    2008-07-01

    Epidemic typhus is transmitted to human beings by the body louse Pediculus humanus corporis. The disease is still considered a major threat by public-health authorities, despite the efficacy of antibiotics, because poor sanitary conditions are conducive to louse proliferation. Until recently, Rickettsia prowazekii, the causal agent, was thought to be confined to human beings and their body lice. Since 1975, R prowazekii infection in human beings has been related to contact with the flying squirrel Glaucomys volans in the USA. Moreover, Brill-Zinsser disease, a relapsed form of epidemic typhus that appears as sporadic cases many years after the initial infection, is unrelated to louse infestation. Stress or a waning immune system are likely to reactivate this earlier persistent infection, which could be the source of new epidemics when conditions facilitate louse infestation. Finally, R prowazekii is a potential category B bioterrorism agent, because it is stable in dried louse faeces and can be transmitted through aerosols. An increased understanding of the pathogenesis of epidemic typhus may be useful for protection against this bacterial threat.

  7. Molecular typing and whole genome next generation sequencing of human adenovirus 8 strains recovered from four 2012 outbreaks of keratoconjunctivitis in New York State.

    Science.gov (United States)

    Lamson Bs, Daryl M; Kajon, Adriana E; Shudt, Matthew; Quinn, Monica; Newman, Alexandra; Whitehouse, Joan; Greenko, Jane; Adams, Eleanor; St George, Kirsten

    2018-05-11

    Ocular infections caused by human adenovirus (HAdV) are highly contagious. The most severe are usually caused by members of species HAdV-D (types HAdV8, 19, 37, 53, 54, and 56) and can manifest as epidemic keratoconjunctivitis (EKC), often resulting in prolonged impairment of vision. During the early months of 2012, EKC outbreaks occurred in neonatal intensive care units (NICUs) in 3 hospitals in New York State (New York and Suffolk Counties). A total of 32 neonates were affected. For 14 of them, HAdV8 was laboratory-confirmed as the causative agent. Nine healthcare workers were also affected with 3 laboratory-confirmed, HAdV-positive EKC. A fourth EKC outbreak was documented among patients attending a private ophthalmology practice in Ulster County involving a total of 35 cases. Epidemiological linkage between the neonatal intensive care unit outbreaks was demonstrated by molecular typing of virus isolates with restriction enzyme analysis and next generation whole genome sequencing. The strain isolated from the ophthalmology clinic was easily distinguishable from the others by restriction enzyme analysis. © 2018 Wiley Periodicals, Inc.

  8. Immune-mediated keratoconjunctivitis sicca in dogs: current perspectives on management

    Directory of Open Access Journals (Sweden)

    Dodi PL

    2015-10-01

    Full Text Available Pier Luigi Dodi Department of Veterinary Medicine Sciences, University of Parma, Parma, Italy Abstract: Keratoconjunctivitis sicca (KCS is a frequent canine ophthalmic disease, resulting from the deficiency of one or more elements in the precorneal tear film. There are different known causes of KCS in dogs, including congenital, metabolic, infectious, drug induced, neurogenic, radiation, iatrogenic, idiopathic, and immune mediated, though the last one is the most prevalent form in dogs. Initially, clinical signs of KCS include blepharospasm caused by ocular pain, mucoid to mucopurulent ocular discharge, and conjunctival hyperemia; secondary bacterial infection may also occur, with chronicity, corneal epithelial hyperplasia, pigmentation, neovascularization, and corneal ulceration. The diagnosis of KCS is based on the presence of consistent clinical signs and measurement of decreased aqueous tear production using the Schirmer tear test. Therapy is based on administering the following topical drugs: ocular lubricant, mucolytics, antibiotics, corticosteroids, pilocarpine, and immunomodulators. These last drugs (eg, cyclosporine, pimecrolimus, and tacrolimus have immunosuppressive activity and stimulate tear production. Furthermore, the nerve growth factor is a new subject matter of the research. Although these therapies are advantageous, stimulation of natural tear production seems to provide the highest recovery in clinical signs and prevention of vision loss. The goal of the following article is to describe the recent developments about KCS in dogs emphasizing the use of new therapies. Keywords: dogs, keratoconjunctivitis sicca, treatment, NGF

  9. Extensive superior limbic keratoconjunctivitis in Graves’ disease: case report and mini-review of the literature

    Directory of Open Access Journals (Sweden)

    Chelala E

    2015-03-01

    Full Text Available Elias Chelala, Hala El Rami, Ali Dirani, Henry Fakhoury, Ali Fadlallah Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon Background: Superior limbic keratoconjunctivitis (SLK is characterized as an inflammation of the superior bulbar conjunctiva with predominant involvement of the superior limbus and adjacent epithelial keratitis.Methods: A 51-year-old woman, with a history of medically controlled Graves’ disease was seen with an extensive SLK involving 5 mm of the superior cornea.Results: Total remission was observed with topical steroids (DXM. Recurrence was observed 1 week after steroid discontinuation, and steroidal treatment was reintroduced with tapering over 1 month. Total remission was then observed for 1 year. Conclusion: Extensive keratitis and vascular pannus in SLK is rarely reported. This form could be treated with topical steroids. Tapering treatment remains essential for long-term success. Keywords: superior limbic keratoconjunctivitis, anti-inflammatory drugs, dexamethasone, triamcinolone, Graves’ disease

  10. Efficacy and safety of low-dose topical tacrolimus in vernal keratoconjunctivitis

    Directory of Open Access Journals (Sweden)

    Shoughy SS

    2016-04-01

    Full Text Available Samir S Shoughy,1 Mahmoud O Jaroudi,1 Khalid F Tabbara1–3 1The Eye Center and The Eye Foundation for Research in Ophthalmology, 2Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia; 3Wilmer Ophthalmological Institute of the Johns Hopkins University School of Medicine, Baltimore, MD, USA Objective: The objective of this study was to evaluate the efficacy and safety of topical low-dose tacrolimus (0.01% solution in patients with vernal keratoconjunctivitis (VKC. Patients and methods: A total of 62 consecutive patients with VKC refractory to conventional treatment were included retrospectively. Tacrolimus 0.01% ophthalmic solution was administered to patients twice daily after discontinuation of all previous topical medications. The duration of treatment ranged from 1 month to 29 months. The clinical symptoms of itching, redness, foreign body sensation, and discharge and the clinical signs of conjunctival hyperemia, conjunctival papillary hypertrophy, limbal infiltration, Trantas dots, and superficial punctate keratopathy were graded as 0 (normal, 1+ (mild, 2+ (moderate, or 3+ (severe. Assessment was carried out before initiation of therapy and on the last visit after treatment. Results: There were 62 patients with VKC comprising 49 male and 13 female patients. The median age was 12 years (range: 5–47 years. The mean visual acuity improved from 20/30 to 20/25 following treatment. There was statistically significant improvement in symptoms of itching (P<0.001, redness (P<0.001, foreign body sensation (P<0.001, and discharge (P<0.001. Statistically significant improvement was also observed in clinical signs of conjunctival hyperemia (P<0.001, limbal infiltration (P<0.001, Trantas dots (P<0.001, superficial punctate keratopathy (P<0.001, and conjunctival papillary hypertrophy (P<0.001. The solution form of tacrolimus was well tolerated. None of the patients developed elevation of intraocular pressure

  11. Diversity of Moraxella spp. strains recovered from infectious bovine keratoconjunctivitis cases in Uruguay.

    Science.gov (United States)

    Sosa, Vanessa; Zunino, Pablo

    2013-11-15

    Infectious bovine keratoconjunctivitis (IBK) is the most common ocular disease that affects cattle throughout the world and it has a very significant economic impact. IBK is caused by members of the genus Moraxella and therapeutic and preventive measures have shown limited success. Vaccines, most of them chemically inactivated bacterins, generally induce a limited protection. In this study, the genetic diversity of Uruguayan clinical Moraxella bovis and Moraxella bovoculi isolates was assessed by RAPD-PCR, ERIC-PCR and BOX-PCR fingerprinting. Also, antibiotic resistance of the Moraxella spp. isolates was assessed utilizing the disk diffusion method. When interspecific molecular diversity was assessed, different bands patterns were observed even within a single outbreak of IBK, showing the coexistence of different genotypes of Moraxella spp. The high genetic diversity within M. bovis and M. bovoculi isolates did not permit to correlate isolates DNA fingerprints with geographical origins, dates or even with both different Moraxella species. Antibiotics resistance patterns showed significant differences between M. bovis and M. bovoculi. This is the first study of diversity that includes M. bovis and M. bovoculi associated to IBK cases. Genetic diversity did not allow to correlate DNA fingerprints of the isolates with geographical origins, isolation dates or even both different Moraxella species. Antibiotics resistance patterns showed differences between M. bovis and M. bovoculi. This remarkable variation within isolates could explain the partial protection induced by commercial vaccines. All these findings could be important for the design of prevention or treatment strategies against IBK.

  12. Canine oral mucosa evaluation as a potential autograft tissue for the treatment of unresponsive keratoconjunctivitis sicca.

    Science.gov (United States)

    Cherry, Rose L; Smith, Jodi D; Ben-Shlomo, Gil

    2018-01-01

    Labial mucosa transplantation for the treatment of canine keratoconjunctivitis sicca (KCS) has been reported recently. Postoperative alleviation of clinical signs was noted and assumed to be the result of labial salivary glands providing lubrication to the ocular tissue. The aim of this study was to evaluate the presence of minor salivary glands (MSG) in the canine oral mucosa. Oral mucosal biopsies were collected from six dogs that died (n = 1) or were euthanized (n = 5) for reasons unrelated to this study. The breeds included were two Doberman Pinschers, one Labrador Retriever, one Portuguese Water Dog, one German Shepherd Dog, and one mixed canine. Three were spayed females, and three were castrated males with the median age of 9 years (range, 6-13 years). Samples were obtained by an 8-mm punch biopsy at the following locations of the canine oral cavity: upper rostral labial mucosa at midline, lower rostral labial mucosa at midline, upper labial mucosa near the commissure, lower labial mucosa near the commissure, and buccal mucosa approximately 1 cm caudal to the commissure. Samples were routinely processed with hematoxylin and eosin, and periodic acid-Schiff stains. Samples were evaluated by light microscopy. At the selected locations, no MSG or other secreting cells were detected. Minor salivary glands are not associated with alleviation of canine KCS symptoms following labial mucosa transplantation. Further studies are needed to determine the mechanism leading to the transient improvement of KCS symptoms in canine patients following labial mucosa transplantation. © 2017 American College of Veterinary Ophthalmologists.

  13. Modeling Epidemic Network Failures

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Fagertun, Anna Manolova

    2013-01-01

    This paper presents the implementation of a failure propagation model for transport networks when multiple failures occur resulting in an epidemic. We model the Susceptible Infected Disabled (SID) epidemic model and validate it by comparing it to analytical solutions. Furthermore, we evaluate...... the SID model’s behavior and impact on the network performance, as well as the severity of the infection spreading. The simulations are carried out in OPNET Modeler. The model provides an important input to epidemic connection recovery mechanisms, and can due to its flexibility and versatility be used...... to evaluate multiple epidemic scenarios in various network types....

  14. TH17 cells mediate inflammation in a novel model of spontaneous experimental autoimmune lacrimal keratoconjunctivitis with neural damage.

    Science.gov (United States)

    Seo, Kyoung Yul; Kitamura, Kazuya; Han, Soo Jung; Kelsall, Brian

    2017-09-27

    Dry eye disease (DED) affects one third of the population worldwide. In prior studies, experimental autoimmune lacrimal keratoconjunctivitis (EALK) induced by desiccating stress in mice has been used as a model of DED. This model is complicated by a requirement for exogenous epithelial cell injury and administration of anticholinergic agents with broad immunologic effects. We sought to develop a novel mouse model of EALK and to demonstrate the responsible pathogenic mechanisms. CD4 + CD45RB high naive T cells with and without CD4 + CD45RB low regulatory T cells were adoptively transferred to C57BL/10 recombination-activating gene 2 (Rag2) -/- mice. The eyes, draining lymph nodes, lacrimal glands, and surrounding tissues of mice with and without spontaneous keratoconjunctivitis were evaluated for histopathologic changes, cellular infiltration, and cytokine production in tissues and isolated cells. Furthermore, the integrity of the corneal nerves was evaluated using whole-tissue immunofluorescence imaging. Gene-deficient naive T cells or RAG2-deficient hosts were evaluated to assess the roles of IFN-γ, IL-17A, and IL-23 in disease pathogenesis. Finally, cytokine levels were determined in the tears of patients with DED. EALK developed spontaneously in C57BL/10 Rag2 -/- mice after adoptive transfer of CD4 + CD45RB high naive T cells and was characterized by infiltration of CD4 + T cells, macrophages, and neutrophils. In addition to lacrimal keratoconjunctivitis, mice had damage to the corneal nerve, which connects components of the lacrimal functional unit. Pathogenic T-cell differentiation was dependent on IL-23p40 and controlled by cotransferred CD4 + CD45RB low regulatory T cells. T H 17 rather than T H 1 CD4 + cells were primarily responsible for EALK, even though levels of both IL-17 and IFN-γ were increased in inflammatory tissues, likely because of their ability to drive expression of CXC chemokines within the cornea and the subsequent influx of myeloid cells

  15. Efficacy and safety of low-dose topical tacrolimus in vernal keratoconjunctivitis.

    Science.gov (United States)

    Shoughy, Samir S; Jaroudi, Mahmoud O; Tabbara, Khalid F

    2016-01-01

    The objective of this study was to evaluate the efficacy and safety of topical low-dose tacrolimus (0.01%) solution in patients with vernal keratoconjunctivitis (VKC). A total of 62 consecutive patients with VKC refractory to conventional treatment were included retrospectively. Tacrolimus 0.01% ophthalmic solution was administered to patients twice daily after discontinuation of all previous topical medications. The duration of treatment ranged from 1 month to 29 months. The clinical symptoms of itching, redness, foreign body sensation, and discharge and the clinical signs of conjunctival hyperemia, conjunctival papillary hypertrophy, limbal infiltration, Trantas dots, and superficial punctate keratopathy were graded as 0 (normal), 1+ (mild), 2+ (moderate), or 3+ (severe). Assessment was carried out before initiation of therapy and on the last visit after treatment. There were 62 patients with VKC comprising 49 male and 13 female patients. The median age was 12 years (range: 5-47 years). The mean visual acuity improved from 20/30 to 20/25 following treatment. There was statistically significant improvement in symptoms of itching (P<0.001), redness (P<0.001), foreign body sensation (P<0.001), and discharge (P<0.001). Statistically significant improvement was also observed in clinical signs of conjunctival hyperemia (P<0.001), limbal infiltration (P<0.001), Trantas dots (P<0.001), superficial punctate keratopathy (P<0.001), and conjunctival papillary hypertrophy (P<0.001). The solution form of tacrolimus was well tolerated. None of the patients developed elevation of intraocular pressure, cataract, or infectious keratitis. Low-dose topical tacrolimus 0.01% solution is effective and safe in the management of patients with refractory VKC.

  16. Microarray-based IgE detection in tears of patients with vernal keratoconjunctivitis.

    Science.gov (United States)

    Leonardi, Andrea; Borghesan, Franco; Faggian, Diego; Plebani, Mario

    2015-11-01

    A specific allergen sensitization can be demonstrated in approximately half of the vernal keratoconjunctivitis (VKC) patients by conventional allergic tests. The measurement of specific IgE in tears using a multiplex allergen microarray may offer advantages to identify local sensitization to a specific allergen. In spring-summer 2011, serum and tears samples were collected from 10 active VKC patients (three females, seven males) and 10 age-matched normal subjects. Skin prick test, symptoms score and full ophthalmological examination were performed. Specific serum and tear IgE were assayed using ImmunoCAP ISAC, a microarray containing 103 components derived from 47 allergens. Normal subjects resulted negative for the presence of specific IgE both in serum and in tears. Of the 10 VKC patients, six resulted positive to specific IgE in serum and/or tears. In three of these six patients, specific IgE was found positive only in tears. Cross-reactivity between specific markers was found in three patients. Grass, tree, mites, animal but also food allergen-specific IgE were found in tears. Conjunctival provocation test performed out of season confirmed the specific local conjunctival reactivity. Multiple specific IgE measurements with single protein allergens using a microarray technique in tear samples are a useful, simple and non-invasive diagnostic tool. ImmunoCAP ISAC detects allergen sensitization at component level and adds important information by defining both cross- and co-sensitization to a large variety of allergen molecules. The presence of specific IgE only in tears of VKC patients reinforces the concept of possible local sensitization. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Genetic parameters of infectious bovine keratoconjunctivitis and its relationship with weight and parasite infestations in Australian tropical Bos taurus cattle

    DEFF Research Database (Denmark)

    Ali, A.; O'Neill, C.J.; Thomson, P.C.

    2012-01-01

    recorded for tick counts, helminth eggs counts as an indicator of intestinal parasites and live weights at several ages including 18 months. Results: Negative genetic correlations were estimated between IBK incidence and weight traits for animals in pre-weaning and post-weaning datasets. Genetic......Background: Infectious bovine keratoconjunctivitis (IBK) or 'pinkeye' is an economically important ocular disease that significantly impacts animal performance. Genetic parameters for IBK infection and its genetic and phenotypic correlations with cattle tick counts, number of helminth (unspecified...... correlations among weight measurements were positive, with moderate to high values. Genetic correlations of IBK incidence with tick counts were positive for the pre-weaning and negative for the post-weaning datasets but negative with helminth eggs counts for the pre-weaning dataset and slightly positive...

  18. Altered cytokine balance in the tear fluid and conjunctiva of patients with Sjögren's syndrome keratoconjunctivitis sicca.

    Science.gov (United States)

    Pflugfelder, S C; Jones, D; Ji, Z; Afonso, A; Monroy, D

    1999-09-01

    To compare epidermal growth factor (EGF) concentration in tear fluid and levels of inflammatory cytokines in the conjunctival epithelium of patients with Sjögren's syndrome keratoconjunctivitis sicca with those of normal controls. Schirmer 1 tear testing, corneal fluorescein staining and conjunctival impression cytology for quantitation of goblet cell density were performed in ten patients with Sjögren's syndrome-associated keratoconjunctivitis sicca and ten asymptomatic normal controls. ELISA was used to detect the concentration of EGF in tear fluid and interleukin 6 in lysates of conjunctival cytology specimens obtained from all subjects. The levels of RNA transcripts encoding inflammatory cytokines [interleukin 1alpha_(IL-1alpha), interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor alpha_(TNF-alpha), and transforming growth factor beta1 (TGF-beta1)] as well as a housekeeping gene (G3PDH) were evaluated in conjunctival cytology specimens taken from all subjects by semiquantitative competitive reverse transcriptase polymerase chain reaction (RT-PCR). Decreased tear fluid EGF concentration was noted in Sjögren's syndrome patients (mean 0.68 +/- 0.59 ng/ml) compared to controls (mean 1.66 +/- 0.45 ng/ml, P = 0.004). Significantly increased levels of IL-1alpha, IL-6, IL-8, TNF-alpha and TGF-beta1 RNA transcripts were found in the conjunctival epithelium of Sjögren's syndrome patients compared to controls (P G3PDH was similar in both groups. The concentration of IL-6 protein was significantly higher in Sjögren's syndrome conjunctiva samples (P = 0.012). Tear EGF concentration correlated with Schirmer 1 scores (rho 0.767, P < 0.001), corneal fluorescein staining scores (rho -0.562, P = 0.01), conjunctival goblet cell density (rho 0.661, P = 0.001) and the levels of IL-1alpha_and IL-8 RNA in the conjunctival epithelium (rho -0.677 and -0.747, respectively, P = 0.001). Both IL-1alpha_and IL-8 RNA in the conjunctival epithelium increased as Schirmer 1

  19. Configuring the autism epidemic

    DEFF Research Database (Denmark)

    Seeberg, Jens; Christensen, Fie Lund Lindegaard

    2017-01-01

    Autism has been described as an epidemic, but this claim is contested and may point to an awareness epidemic, i.e. changes in the definition of what autism is and more attention being invested in diagnosis leading to a rise in registered cases. The sex ratio of children diagnosed with autism...... is skewed in favour of boys, and girls with autism tend to be diagnosed much later than boys. Building and further developing the notion of ‘configuration’ of epidemics, this article explores the configuration of autism in Denmark, with a particular focus on the health system and social support to families...... with children diagnosed with autism, seen from a parental perspective. The article points to diagnostic dynamics that contribute to explaining why girls with autism are not diagnosed as easily as boys. We unfold these dynamics through the analysis of a case of a Danish family with autism....

  20. Global HIV/AIDS Epidemic

    Science.gov (United States)

    ... Policy The Global HIV/AIDS Epidemic The Global HIV/AIDS Epidemic Published: Nov 29, 2017 Facebook Twitter ... 2001-FY 2018 Request The Global Response to HIV/AIDS International efforts to combat HIV began in ...

  1. Networked SIS Epidemics With Awareness

    KAUST Repository

    Paarporn, Keith; Eksin, Ceyhun; Weitz, Joshua S.; Shamma, Jeff S.

    2017-01-01

    We study a susceptible-infected-susceptible epidemic process over a static contact network where the nodes have partial information about the epidemic state. They react by limiting their interactions with their neighbors when they believe

  2. epidemic teach us?

    African Journals Online (AJOL)

    frequently brings shame, fear and guilt: dealing with this for some will begin a process of .... 'AZT treatment will have a limited effect on the epidemic, as we are targeting ... others to make the decisions that control my life. It is ironic that a society ...

  3. The Obesity Epidemic

    Centers for Disease Control (CDC) Podcasts

    2011-07-18

    Learn about obesity and the community initiatives taking place to prevent and reduce this epidemic.  Created: 7/18/2011 by National Center for Chronic Disease Prevention and Health Promotion, Division of Nutrition, Physical Activity and Obesity.   Date Released: 7/18/2011.

  4. Kanpur epidemic: Time course

    Indian Academy of Sciences (India)

    The first peak was related to water contamination which began in December 1990. The second peak was related to failure of municipal authorities to chlorinate water during the 2nd week of February 1991. The epidemic came under control quickly after water contamination was controlled, providing confirmation for role of ...

  5. Trauma - the malignant epidemic

    African Journals Online (AJOL)

    national problem and the term 'malignant epidemic' is more applicable. These two ... In 1984 it stood at just over 400 000 per annum and today the figure is close to ... breadwinner, loss of productivity, expenses of rehabilitation and care of the ...

  6. Cyber Epidemic Models with Dependences

    OpenAIRE

    Xu, Maochao; Da, Gaofeng; Xu, Shouhuai

    2016-01-01

    Studying models of cyber epidemics over arbitrary complex networks can deepen our understanding of cyber security from a whole-system perspective. In this paper, we initiate the investigation of cyber epidemic models that accommodate the {\\em dependences} between the cyber attack events. Due to the notorious difficulty in dealing with such dependences, essentially all existing cyber epidemic models have assumed them away. Specifically, we introduce the idea of Copulas into cyber epidemic mode...

  7. Hepatitis E epidemics in India

    Indian Academy of Sciences (India)

    The first well recorded epidemic was in 1955-56 here in Delhi with nearly 30000 cases. Large outbreaks occurred in 1978 in Kashmir. My interest in this disease began in 1991 during investigations into a large epidemic of hepatitis E in Kanpur that my mentor, later Prof SR Naik, and I undertook. I will use this epidemic as an ...

  8. Epidemics on interconnected networks

    Science.gov (United States)

    Dickison, Mark; Havlin, S.; Stanley, H. E.

    2012-06-01

    Populations are seldom completely isolated from their environment. Individuals in a particular geographic or social region may be considered a distinct network due to strong local ties but will also interact with individuals in other networks. We study the susceptible-infected-recovered process on interconnected network systems and find two distinct regimes. In strongly coupled network systems, epidemics occur simultaneously across the entire system at a critical infection strength βc, below which the disease does not spread. In contrast, in weakly coupled network systems, a mixed phase exists below βc of the coupled network system, where an epidemic occurs in one network but does not spread to the coupled network. We derive an expression for the network and disease parameters that allow this mixed phase and verify it numerically. Public health implications of communities comprising these two classes of network systems are also mentioned.

  9. First Isolation of Dengue Virus from the 2010 Epidemic in Nepal

    OpenAIRE

    Pandey, Basu D.; Nabeshima, Takeshi; Pandey, Kishor; Rajendra, Saroj P.; Shah, Yogendra; Adhikari, Bal R.; Gupta, Govinda; Gautam, Ishan; Tun, Mya M. N.; Uchida, Reo; Shrestha, Mahendra; Kurane, Ichiro; Morita, Kouichi

    2013-01-01

    Denguei is an emerging disease in Nepal and was first observed as an outbreak in nine lowland districts in 2006. In 2010, however, a large epidemic of dengue occurred with 4,529 suspected and 917 serologicallyconfirmed cases and five deaths reported in government hospitals in Nepal. The collection of demographic information was performed along with an entomological survey and clinical evaluation of the patients. A total of 280 serum samples were collected from suspected dengue patients. These...

  10. (Epidemic of bacillary dysentery)

    Energy Technology Data Exchange (ETDEWEB)

    Auger, P.; Pouliot, B.; De Grace, M.; Milot, C.; Lafortune, M.; Bergeron, Z.

    1981-10-01

    An outbreak of bacillary dysentery in 1978 affecting 928 persons, most of whom were living in the village of St-Jacques, PQ, is described. An epidemiologic study suggested the water supply as the source of the infection, and it was established that the water carried by the municipal aqueduct was contaminated by feces containing the causal agent, Shigella sonnei. This epidemic, the largest mentioned in he Canadian medical literature, demonstrates how contagious this infection is.

  11. Ebola epidemic--Liberia, March-October 2014.

    Science.gov (United States)

    Nyenswah, Tolbert; Fahnbulleh, Miatta; Massaquoi, Moses; Nagbe, Thomas; Bawo, Luke; Falla, James Dorbor; Kohar, Henry; Gasasira, Alex; Nabeth, Pierre; Yett, Sheldon; Gergonne, Bernadette; Casey, Sean; Espinosa, Benjamin; McCoy, Andrea; Feldman, Heinz; Hensley, Lisa; Baily, Mark; Fields, Barry; Lo, Terrence; Lindblade, Kim; Mott, Josh; Boulanger, Lucy; Christie, Athalia; Wang, Susan; Montgomery, Joel; Mahoney, Frank

    2014-11-21

    On March 21, 2014, the Guinea Ministry of Health reported the outbreak of an illness characterized by fever, severe diarrhea, vomiting and a high fatality rate (59%), leading to the first known epidemic of Ebola virus disease (Ebola) in West Africa and the largest and longest Ebola epidemic in history. As of November 2, Liberia had reported the largest number of cases (6,525) and deaths (2,697) among the three affected countries of West Africa with ongoing transmission (Guinea, Liberia, and Sierra Leone). The response strategy in Liberia has included management of the epidemic through an incident management system (IMS) in which the activities of all partners are coordinated. Within the IMS, key strategies for epidemic control include surveillance, case investigation, laboratory confirmation, contact tracing, safe transportation of persons with suspected Ebola, isolation, infection control within the health care system, community engagement, and safe burial. This report provides a brief overview of the progression of the epidemic in Liberia and summarizes the interventions implemented.

  12. Prime Suspect, Second Row Center

    Science.gov (United States)

    Laird, Ellen A.

    2011-01-01

    His father had been hacked to death in his own bed with an ax the previous November. His mother was similarly brutalized and left for dead with her husband but survived. On the last Monday of that August, after several months and many investigative twists, turns, and fumbles, there sat the son--the prime suspect--in Ellen Laird's literature class,…

  13. Vernal keratoconjunctivitis in school children in Rwanda and its association with socio-economic status: a population-based survey.

    Science.gov (United States)

    Smedt, Stefan De; Nkurikiye, John; Fonteyne, Yannick; Hogewoning, Arjan; Esbroeck, Marjan Van; Bacquer, Dirk De; Tuft, Stephen; Gilbert, Clare; Delanghe, Joris; Kestelyn, Philippe

    2011-10-01

    Vernal keratoconjunctivitis (VKC) is an allergic eye disease and an important cause of hospital referral among children in Africa and Asia. Hospital-based studies have suggested a role for parasites in its pathogenesis. To determine the prevalence and risk factors for VKC in Central Africa, we conducted a nested population-based case control study in Rwanda, involving randomly selected primary schools from different environments (rural/urban) and climate. A prevalence of VKC of 4.0% (95% confidence interval 3.3-4.7%) was found among 3,041 children studied (participation rate 94.7%). The intestinal parasitic burden was not related to VKC. Besides hot dry climate (odds ratio [OR] = 1.5, P = 0.05) and male gender (OR = 1.7, P = 0.005), multivariate analysis identified higher economic status as a risk for VKC (OR = 1.4, P = 0.005). The effect on VKC of higher economic status appears not to act through differences in parasitic intestinal load.

  14. Assessment of tear film osmolarity using the TearLab™ osmometer in normal dogs and dogs with keratoconjunctivitis sicca.

    Science.gov (United States)

    Sebbag, Lionel; Park, Shin Ae; Kass, Philip H; Maggs, David J; Attar, Mayssa; Murphy, Christopher J

    2017-07-01

    To evaluate repeatability and reproducibility of tear osmolarity measured using the TearLab ™ osmometer in normal dogs and to assess its diagnostic potential in dogs with keratoconjunctivitis sicca (KCS). Beagle dogs; six normal and five with KCS. Tear osmolarity and Schirmer tear test-1 (STT-1) values were obtained at various times. Normal dogs were assessed for diurnal variation and repeatability and reproducibility of measurements. Dogs with KCS were evaluated before and after 5 months' topical twice-daily therapy with 2% cyclosporine. Mean ± SD tear osmolarity (mOsm/L) was significantly higher in normal dogs (337.4 ± 16.2) than in dogs with KCS before therapy (306.2 ± 18.0; P dogs, tear osmolarity readings were stable during the daytime (P = 0.99). Repeated measurements revealed high variability and typically poor-to-moderate repeatability and reproducibility, although this was improved by taking three successive measurements at each session. Considering combined data from all dogs, a positive correlation existed between STT-1 and tear osmolarity measurements (Pearson's correlation test, P = 0.04, r = 0.62). Canine tear osmolarity as determined by TearLab ™ osmometer was variable, required multiple readings to be informative, and differed from values reported for humans. Dogs with KCS had a lower tear osmolarity than did normal dogs, and this increased following cyclosporine therapy. © 2016 American College of Veterinary Ophthalmologists.

  15. Epidemic as a natural process.

    Science.gov (United States)

    Koivu-Jolma, Mikko; Annila, Arto

    2018-05-01

    Mathematical epidemiology is a well-recognized discipline to model infectious diseases. It also provides guidance for public health officials to limit outbreaks. Nevertheless, epidemics take societies by surprise every now and then, for example, when the Ebola virus epidemic raged seemingly unrestrained in Western Africa. We provide insight to this capricious character of nature by describing the epidemic as a natural process, i.e., a phenomenon governed by thermodynamics. Our account, based on statistical mechanics of open systems, clarifies that it is impossible to predict accurately epidemic courses because everything depends on everything else. Nonetheless, the thermodynamic theory yields a comprehensive and analytical view of the epidemic. The tenet subsumes various processes in a scale-free manner from the molecular to the societal levels. The holistic view accentuates overarching procedures in arresting and eradicating epidemics. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Epidemics spread in heterogeneous populations

    Science.gov (United States)

    Capała, Karol; Dybiec, Bartłomiej

    2017-05-01

    Individuals building populations are subject to variability. This variability affects progress of epidemic outbreaks, because individuals tend to be more or less resistant. Individuals also differ with respect to their recovery rate. Here, properties of the SIR model in inhomogeneous populations are studied. It is shown that a small change in model's parameters, e.g. recovery or infection rate, can substantially change properties of final states which is especially well-visible in distributions of the epidemic size. In addition to the epidemic size and radii distributions, the paper explores first passage time properties of epidemic outbreaks.

  17. Ongoing dengue epidemic - Angola, June 2013.

    Science.gov (United States)

    2013-06-21

    On April 1, 2013, the Public Health Directorate of Angola announced that six cases of dengue had been reported to the Ministry of Health of Angola (MHA). As of May 31, a total of 517 suspected dengue cases had been reported and tested for dengue with a rapid diagnostic test (RDT). A total of 313 (60.5%) specimens tested positive for dengue, including one from a patient who died. All suspected cases were reported from Luanda Province, except for two from Malanje Province. Confirmatory diagnostic testing of 49 specimens (43 RDT-positive and six RDT-negative) at the CDC Dengue Branch confirmed dengue virus (DENV) infection in 100% of the RDT-positive specimens and 50% of the RDT-negative specimens. Only DENV-1 was detected by molecular diagnostic testing. Phylogenetic analysis indicated this virus has been circulating in the region since at least 1968, strongly suggesting that dengue is endemic in Angola. Health-care professionals throughout Angola should be aware of the ongoing epidemic, the recommended practices for clinical management of dengue patients, and the need to report cases to MHA. Persons in Angola should seek medical care for acute febrile illness to reduce the risk for developing complications. Laboratory-confirmed dengue also has been reported from seven countries on four continents among persons who had recently traveled to Luanda, including 79 persons from Portugal. Angola is the third of four African countries to report a dengue outbreak in 2013. Persons returning from Africa with acute febrile illness should seek medical care, including testing for DENV infection, and suspected cases should be reported to public health authorities.

  18. Provider-initiated HIV testing and counselling for TB patients and suspects in Nairobi, Kenya.

    Science.gov (United States)

    Odhiambo, J; Kizito, W; Njoroge, A; Wambua, N; Nganga, L; Mburu, M; Mansoer, J; Marum, L; Phillips, E; Chakaya, J; De Cock, K M

    2008-03-01

    Integrated tuberculosis (TB) and human immunodeficiency virus (HIV) services in a resource-constrained setting. Pilot provider-initiated HIV testing and counselling (PITC) for TB patients and suspects. Through partnerships, resources were mobilised to establish and support services. After community sensitisation and staff training, PITC was introduced to TB patients and then to TB suspects from December 2003 to December 2005. Of 5457 TB suspects who received PITC, 89% underwent HIV testing. Although not statistically significant, TB suspects with TB disease had an HIV prevalence of 61% compared to 63% for those without. Of the 614 suspects who declined HIV testing, 402 (65%) had TB disease. Of 2283 patients referred for cotrimoxazole prophylaxis, 1951 (86%) were enrolled, and of 1727 patients assessed for antiretroviral treatment (ART), 1618 (94%) were eligible and 1441 (83%) started treatment. PITC represents a paradigm shift and is feasible and acceptable to TB patients and TB suspects. Clear directives are nevertheless required to change practice. When offered to TB suspects, PITC identifies large numbers of persons requiring HIV care. Community sensitisation, staff training, multitasking and access to HIV care contributed to a high acceptance of HIV testing. Kenya is using this experience to inform national response and advocate wide PITC implementation in settings faced with the TB-HIV epidemic.

  19. Epidemic modeling in complex realities.

    Science.gov (United States)

    Colizza, Vittoria; Barthélemy, Marc; Barrat, Alain; Vespignani, Alessandro

    2007-04-01

    In our global world, the increasing complexity of social relations and transport infrastructures are key factors in the spread of epidemics. In recent years, the increasing availability of computer power has enabled both to obtain reliable data allowing one to quantify the complexity of the networks on which epidemics may propagate and to envision computational tools able to tackle the analysis of such propagation phenomena. These advances have put in evidence the limits of homogeneous assumptions and simple spatial diffusion approaches, and stimulated the inclusion of complex features and heterogeneities relevant in the description of epidemic diffusion. In this paper, we review recent progresses that integrate complex systems and networks analysis with epidemic modelling and focus on the impact of the various complex features of real systems on the dynamics of epidemic spreading.

  20. Epidemics after Natural Disasters

    Science.gov (United States)

    Gayer, Michelle; Connolly, Maire A.

    2007-01-01

    The relationship between natural disasters and communicable diseases is frequently misconstrued. The risk for outbreaks is often presumed to be very high in the chaos that follows natural disasters, a fear likely derived from a perceived association between dead bodies and epidemics. However, the risk factors for outbreaks after disasters are associated primarily with population displacement. The availability of safe water and sanitation facilities, the degree of crowding, the underlying health status of the population, and the availability of healthcare services all interact within the context of the local disease ecology to influence the risk for communicable diseases and death in the affected population. We outline the risk factors for outbreaks after a disaster, review the communicable diseases likely to be important, and establish priorities to address communicable diseases in disaster settings. PMID:17370508

  1. The epidemic of methylisothiazolinone

    DEFF Research Database (Denmark)

    Schwensen, Jakob F; Uter, Wolfgang; Bruze, Magnus

    2017-01-01

    BACKGROUND: The use of methylisothiazolinone (MI) in cosmetic products has caused an unprecedented epidemic of MI contact allergy. Current data concerning exposures at a European level are required. OBJECTIVES: To describe demographics and MI exposures for European patients with MI contact allergy....... METHODS: Eleven European dermatology departments from eight European countries prospectively collected data between 1 May and 31 October 2015 among consecutive patients who had positive patch test reactions to MI (2000 ppm aq.). RESULTS: A total of 6.0% (205/3434; range 2.6-13.0%) of patients had positive...... patch test reactions to MI. Dermatitis most frequently affected the hands (43.4%), face (32.7%), arms (14.6%), and eyelids (11.7%); 12.7% had widespread dermatitis. For 72.7% (149/205), MI contact allergy was currently relevant mainly because of exposure to cosmetic products (83.2%; 124...

  2. Clinical evaluation of a nutraceutical diet as an adjuvant to pharmacological treatment in dogs affected by Keratoconjunctivitis sicca.

    Science.gov (United States)

    Destefanis, Simona; Giretto, Daniela; Muscolo, Maria Cristina; Di Cerbo, Alessandro; Guidetti, Gianandrea; Canello, Sergio; Giovazzino, Angela; Centenaro, Sara; Terrazzano, Giuseppe

    2016-09-22

    Canine keratoconjunctivitis sicca (cKCS) is an inflammatory eye condition related to a deficiency in the tear aqueous fraction. Etiopathogenesis of such disease is substantially multifactorial, combining the individual genetic background with environmental factors that contribute to the process of immunological tolerance disruption and, as a consequence, to the emergence of autoimmunity disease. In this occurrence, it is of relevance the role of the physiological immune-dysregulation that results in immune-mediated processes at the basis of cKCS. Current therapies for this ocular disease rely on immunosuppressive treatments. Clinical response to treatment frequently varies from poor to good, depending on the clinical-pathological status of eyes at diagnosis and on individual response to therapy. In the light of the variability of clinical response to therapies, we evaluated the use of an anti-inflammatory/antioxidant nutraceutical diet with potential immune-modulating activity as a therapeutical adjuvant in cKCS pharmacological treatment. Such combination was administered to a cohort of dogs affected by cKCS in which the only immunosuppressive treatment resulted poorly responsive or ineffective in controlling the ocular symptoms. Fifty dogs of different breeds affected by immune-mediated cKCS were equally distributed and randomly assigned to receive either a standard diet (control, n = 25) or the nutraceutical diet (treatment group, n = 25) both combined with standard immunosuppressive therapy over a 60 days period. An overall significant improvement of all clinical parameters (tear production, conjunctival inflammation, corneal keratinization, corneal pigment density and mucus discharge) and the lack of food-related adverse reactions were observed in the treatment group (p metabolic changes could affect the immune response orchestration in a model of immune-mediated ocular disease, as represented by cKCS.

  3. Evaluation of retinal nerve fiber layer thickness in vernal keratoconjunctivitis patients under long-term topical corticosteroid therapy.

    Science.gov (United States)

    Cingu, Abdullah Kursat; Cinar, Yasin; Turkcu, Fatih Mehmet; Sahinoglu-Keskek, Nedime; Sahin, Alparslan; Sahin, Muhammed; Yuksel, Harun; Caca, Ihsan

    2014-09-01

    The aim of this study was to evaluate the retinal nerve fiber layer (RNFL) thickness in vernal keratoconjunctivitis (VKC) patients who were under long-term topical corticosteroid therapy. Thirty-six eyes of 36 VKC patients with clear cornea and normal videokeratography and 40 eyes of 40 age- and gender-matched normal children were included in the study. Clinical and demographic characteristics of the patients were noted and detailed ophthalmological examination was performed. Visual acuity (VA), spherical equivalent (SE), axial length (AL) and RNFL thickness measurements were compared between the groups. To correct ocular magnification effect on RNFL, we used Littmann's formula. All VKC patients had history of topical corticosteroid use and the mean duration of the topical corticosteroid use was 23.8 ± 9.09 months. There was no significant difference between the groups in terms of intraocular pressure (IOP). VKC group had significantly worse VA, greater SE and AL and thinner mean global, superior and inferior RNFL thickness. There were significant negative correlations between the duration of topical corticosteroid use and the mean global, superior and temporal RNFL thickness in VKC group. After correction of magnification effect, VKC group still had thinner mean global, superior and inferior RNFL thickness, and significant difference between the groups in inferior RNFL thickness did not disappear. Significant RNFL thickness difference between the groups suggests a possible effect of long-term corticosteroid use in VKC patients. Because visual field (VF) analysis in pediatric patients is difficult to perform and IOP may be illusive, RNFL thickness measurements in addition to routine examinations in VKC patients may help clinicians in their practice.

  4. Reemergence of enterovirus 71 epidemic in northern Taiwan, 2012.

    Science.gov (United States)

    Luo, Shu-Ting; Chiang, Pai-Shan; Chung, Wan-Yu; Chia, Min-Yuan; Tsao, Kuo-Chien; Wang, Ying-Hsiang; Lin, Tzou-Yien; Lee, Min-Shi

    2015-01-01

    Enterovirus 71 (EV71) belongs to picornavirus family and could be classified phylogenetically into three major genogroups (A, B and C) including 11 genotypes (A, B1-B5 and C1-C5). Since 1997, EV71 has caused large-scale of epidemics with neurological complications in Asian children. In Taiwan, nationwide EV71 epidemics with different predominant genotypes have occurred cyclically since 1998. A nationwide EV71 epidemic occurred again in 2012. We conducted genetic and antigenic characterizations of the 2012 epidemic. Chang Gung Memorial Hospital (CGMH) is a medical center in northern Taiwan. In CGMH, specimens were collected from pediatric inpatients with suspected enterovirus infections for virus isolation. Enterovirus isolates were serotyped and genotyped and sera from EV71 inpatients were collected for measuring neutralizing antibody titers. There were 10, 16 and 99 EV71 inpatients identified in 2010, 2011 and 2012, respectively. There were 82 EV71 isolates genotyped, which identified 17 genotype C4a viruses and 65 genotype B5 viruses. The genotype B5 viruses were not detected until November 2011 and caused epidemics in 2012. Interestingly, the B5-2011 viruses were genetically distinguishable from the B5 viruses causing the 2008 epidemic and are likely introduced from China or Southeastern Asia. Based on antigenic analysis, minor antigenic variations were detected among the B5-2008, B5-2011, C4a-2008 and C4a-2012 viruses but these viruses antigenically differed from genotype A. Genotype B5 and C4a viruses antigenically differ from genotype A viruses which have disappeared globally for 30 years but have been detected in China since 2008. Enterovirus surveillance should monitor genetic and antigenic variations of EV71.

  5. Epidemic cholera spreads like wildfire

    Science.gov (United States)

    Roy, Manojit; Zinck, Richard D.; Bouma, Menno J.; Pascual, Mercedes

    2014-01-01

    Cholera is on the rise globally, especially epidemic cholera which is characterized by intermittent and unpredictable outbreaks that punctuate periods of regional disease fade-out. These epidemic dynamics remain however poorly understood. Here we examine records for epidemic cholera over both contemporary and historical timelines, from Africa (1990-2006) and former British India (1882-1939). We find that the frequency distribution of outbreak size is fat-tailed, scaling approximately as a power-law. This pattern which shows strong parallels with wildfires is incompatible with existing cholera models developed for endemic regions, as it implies a fundamental role for stochastic transmission and local depletion of susceptible hosts. Application of a recently developed forest-fire model indicates that epidemic cholera dynamics are located above a critical phase transition and propagate in similar ways to aggressive wildfires. These findings have implications for the effectiveness of control measures and the mechanisms that ultimately limit the size of outbreaks.

  6. [Epidemic parotiditis, a reportable disease].

    Science.gov (United States)

    Boverhoff, J C; Baart, J A

    2013-01-01

    Three consecutive patients with an acute swelling of one of the cheeks, were diagnosed with epidemic parotiditis. The first phase of the diagnostic procedure for an acute cheek swelling is to eliminate the possibility of odontogenic causes. When odontogenic problems have been excluded, non-dentition-related causes may be considered. An acute, progressive swelling in the preauricular area can often be attributed to an inflammation of the parotid gland, but epidemic parotiditis should also be considered. Epidemic parotiditis, or mumps, is caused by the mumps virus. Contamination occurs aerogenically. In the Netherlands, mumps vaccine is an ingredient of the governmental combined mump-measles-rubella inoculation programme. However, in recent years several small-scale parotiditis epidemics have broken out, predominantly among young, inoculated adults. Oropharyngeal mucus and blood samples are needed to diagnose the disease. Each case of the disease should be reported to the community healthcare service.

  7. Virus-Specific Differences in Rates of Disease during the 2010 Dengue Epidemic in Puerto Rico

    Science.gov (United States)

    Sharp, Tyler M.; Hunsperger, Elizabeth; Santiago, Gilberto A.; Muñoz-Jordan, Jorge L.; Santiago, Luis M.; Rivera, Aidsa; Rodríguez-Acosta, Rosa L.; Gonzalez Feliciano, Lorenzo; Margolis, Harold S.; Tomashek, Kay M.

    2013-01-01

    Background Dengue is a potentially fatal acute febrile illness (AFI) caused by four mosquito-transmitted dengue viruses (DENV-1–4) that are endemic in Puerto Rico. In January 2010, the number of suspected dengue cases reported to the passive dengue surveillance system exceeded the epidemic threshold and an epidemic was declared soon after. Methodology/Principal Findings To characterize the epidemic, surveillance and laboratory diagnostic data were compiled. A suspected case was a dengue-like AFI in a person reported by a health care provider with or without a specimen submitted for diagnostic testing. Laboratory-positive cases had: (i) DENV nucleic acid detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in an acute serum specimen; (ii) anti-DENV IgM antibody detected by ELISA in any serum specimen; or (iii) DENV antigen or nucleic acid detected in an autopsy-tissue specimen. In 2010, a total of 26,766 suspected dengue cases (7.2 per 1,000 residents) were identified, of which 46.6% were laboratory-positive. Of 7,426 RT-PCR-positive specimens, DENV-1 (69.0%) and DENV-4 (23.6%) were detected more frequently than DENV-2 (7.3%) and DENV-3 (Puerto Rico in the late 1960's. This epidemic re-emphasizes the need for more effective primary prevention interventions to reduce the morbidity and mortality of dengue. PMID:23593526

  8. Genetic parameters of infectious bovine keratoconjunctivitis and its relationship with weight and parasite infestations in Australian tropical Bos taurus cattle

    Directory of Open Access Journals (Sweden)

    Ali Abdirahman A

    2012-07-01

    Full Text Available Abstract Background Infectious bovine keratoconjunctivitis (IBK or ‘pinkeye’ is an economically important ocular disease that significantly impacts animal performance. Genetic parameters for IBK infection and its genetic and phenotypic correlations with cattle tick counts, number of helminth (unspecified species eggs per gram of faeces and growth traits in Australian tropically adapted Bos taurus cattle were estimated. Methods Animals were clinically examined for the presence of IBK infection before and after weaning when the calves were 3 to 6 months and 15 to 18 months old, respectively and were also recorded for tick counts, helminth eggs counts as an indicator of intestinal parasites and live weights at several ages including 18 months. Results Negative genetic correlations were estimated between IBK incidence and weight traits for animals in pre-weaning and post-weaning datasets. Genetic correlations among weight measurements were positive, with moderate to high values. Genetic correlations of IBK incidence with tick counts were positive for the pre-weaning and negative for the post-weaning datasets but negative with helminth eggs counts for the pre-weaning dataset and slightly positive for the post-weaning dataset. Genetic correlations between tick and helminth eggs counts were moderate and positive for both datasets. Phenotypic correlations of IBK incidence with helminth eggs per gram of faeces were moderate and positive for both datasets, but were close to zero for both datasets with tick counts. Conclusions Our results suggest that genetic selection against IBK incidence in tropical cattle is feasible and that calves genetically prone to acquire IBK infection could also be genetically prone to have a slower growth. The positive genetic correlations among weight traits and between tick and helminth eggs counts suggest that they are controlled by common genes (with pleiotropic effects. Genetic correlations between IBK incidence

  9. Genetic parameters of infectious bovine keratoconjunctivitis and its relationship with weight and parasite infestations in Australian tropical Bos taurus cattle.

    Science.gov (United States)

    Ali, Abdirahman A; O'Neill, Christopher J; Thomson, Peter C; Kadarmideen, Haja N

    2012-07-27

    Infectious bovine keratoconjunctivitis (IBK) or 'pinkeye' is an economically important ocular disease that significantly impacts animal performance. Genetic parameters for IBK infection and its genetic and phenotypic correlations with cattle tick counts, number of helminth (unspecified species) eggs per gram of faeces and growth traits in Australian tropically adapted Bos taurus cattle were estimated. Animals were clinically examined for the presence of IBK infection before and after weaning when the calves were 3 to 6 months and 15 to 18 months old, respectively and were also recorded for tick counts, helminth eggs counts as an indicator of intestinal parasites and live weights at several ages including 18 months. Negative genetic correlations were estimated between IBK incidence and weight traits for animals in pre-weaning and post-weaning datasets. Genetic correlations among weight measurements were positive, with moderate to high values. Genetic correlations of IBK incidence with tick counts were positive for the pre-weaning and negative for the post-weaning datasets but negative with helminth eggs counts for the pre-weaning dataset and slightly positive for the post-weaning dataset. Genetic correlations between tick and helminth eggs counts were moderate and positive for both datasets. Phenotypic correlations of IBK incidence with helminth eggs per gram of faeces were moderate and positive for both datasets, but were close to zero for both datasets with tick counts. Our results suggest that genetic selection against IBK incidence in tropical cattle is feasible and that calves genetically prone to acquire IBK infection could also be genetically prone to have a slower growth. The positive genetic correlations among weight traits and between tick and helminth eggs counts suggest that they are controlled by common genes (with pleiotropic effects). Genetic correlations between IBK incidence and tick and helminth egg counts were moderate and opposite between pre

  10. The worldwide obesity epidemic.

    Science.gov (United States)

    James, P T; Leach, R; Kalamara, E; Shayeghi, M

    2001-11-01

    The recent World Health Organization (WHO) agreement on the standardized classification of overweight and obese, based on body mass index (BMI), allows a comparable analysis of prevalence rates worldwide for the first time. In Asia, however, there is a demand for a more limited range for normal BMIs (i.e., 18.5 to 22.9 kg/m(2) rather than 18.5 to 24.9 kg/m(2)) because of the high prevalence of comorbidities, particularly diabetes and hypertension. In children, the International Obesity Task-Force age-, sex-, and BMI-specific cutoff points are increasingly being used. We are currently evaluating BMI data globally as part of a new millennium analysis of the Global Burden of Disease. WHO is analyzing data in terms of 20 or more principal risk factors contributing to the primary causes of disability and lost lives in the 191 countries within the WHO. The prevalence rates for overweight and obese people are different in each region, with the Middle East, Central and Eastern Europe, and North America having higher prevalence rates. In most countries, women show a greater BMI distribution with higher obesity rates than do men. Obesity is usually now associated with poverty, even in developing countries. Relatively new data suggest that abdominal obesity in adults, with its associated enhanced morbidity, occurs particularly in those who had lower birth weights and early childhood stunting. Waist measurements in nationally representative studies are scarce but will now be needed to estimate the full impact of the worldwide obesity epidemic.

  11. Temporo-spatial dynamics and behavioural patterns of 2012 cholera epidemic in the African mega-city of Conakry, Guinea.

    Science.gov (United States)

    Blake, Alexandre; Keita, Veronique Sarr; Sauvageot, Delphine; Saliou, Mamadou; Njanpop, Berthe Marie; Sory, Fode; Sudre, Bertrand; Lamine, Koivogui; Mengel, Martin; Gessner, Bradford D; Sakoba, Keita

    2018-02-15

    Cholera is endemic in Guinea, having suffered consecutive outbreaks from 2004 to 2008 followed by a lull until the 2012 epidemic. Here we describe the temporal-spatial and behavioural characteristics of cholera cases in Conakry during a three-year period, including the large-scale 2012 epidemic. We used the national and African Cholera Surveillance Network (Africhol) surveillance data collected from every cholera treatment centre in Conakry city from August 2011 to December 2013. The prevalence of suspect and confirmed cholera cases, the case fatality ratio (CFR), and the factors associated with suspected cholera were described according to three periods: pre-epidemic (A), epidemic 2012 (B) and post epidemic (C). Weekly attack rates and temporal-spatial clustering were calculated at municipality level for period B. Cholera was confirmed by culture at the cholera national reference laboratory. A total of 4559 suspect cases were reported: 66, 4437, and 66 suspect cases in periods A, B and C, respectively. Among the 204 suspect cases with culture results available, 6%, 60%, and 70% were confirmed in periods A, B, and C, respectively. With 0.3%, the CFR was significantly lower in period B than in periods A (7.6%) and C (7.1%). The overall attack rate was 0.28% in period B, ranging from 0.17% to 0.31% across municipalities. Concomitantly, a cluster of cases was identified in two districts in the northern part of Conakry. At 14%, rice water stools were less frequent in period A than in period B and C (78% and 84%). Dehydration (31% vs 94% and 89%) and coma (0.4% vs 3.1% and 2.9%) were lower during period B than in periods A and C. The treatment of drinking water was less frequent in period A, while there were more reports of recent travel in period C. The epidemic dynamic and the sociological description of suspect cases before, during, and after the large-scale epidemic revealed that the Vibrio cholerae was already present before the epidemic. However, it appeared that

  12. Presentation of suspected pediatric uveitis.

    Science.gov (United States)

    Saeed, Muhammad Usman; Raza, Syed Hamid; Goyal, Sudeshna; Cleary, Gavin; Newman, William David; Chandna, Arvind

    2014-01-01

    Presentation of suspected pediatric uveitis: Pediatric uveitis is usually managed in specialized ophthalmic centers in the UK. Meaningful data acquisition in these clinics may be helpful in clinical governance, and healthcare planning in a specialty that is gradually changing due to changes in treatment choices. Retrospective analysis of prospectively acquired data in the Liverpool pediatric uveitis database was performed. Analysis of our data, based on 147 patients, with a mean age of 10 years, indicated a female to male ratio of 2:1. 99% of patients were Caucasian. Our data indicates 86% of all patients attending the uveitis clinic were diagnosed with juvenile idiopathic arthritis, followed by intermediate uveitis 5% and idiopathic uveitis 4%. 46% of patients required treatment. Systemic treatment included methotrexate (34%), prednisolone (14%), etanercept (6%), ciclosporin (6%), mycophenolate (3%), and infliximab (1%). Severe visual loss (defined by counting fingers or below vision) was seen in 10 eyes despite appropriately treated chronic uveitis. Our data shows uveitis-related ocular morbidity in a predominantly pediatric Caucasian population. Patients with severe and chronic uveitis may experience significant uveitis-related complications and subsequent visual loss despite aggressive treatment.

  13. Epidemic processes in complex networks

    Science.gov (United States)

    Pastor-Satorras, Romualdo; Castellano, Claudio; Van Mieghem, Piet; Vespignani, Alessandro

    2015-07-01

    In recent years the research community has accumulated overwhelming evidence for the emergence of complex and heterogeneous connectivity patterns in a wide range of biological and sociotechnical systems. The complex properties of real-world networks have a profound impact on the behavior of equilibrium and nonequilibrium phenomena occurring in various systems, and the study of epidemic spreading is central to our understanding of the unfolding of dynamical processes in complex networks. The theoretical analysis of epidemic spreading in heterogeneous networks requires the development of novel analytical frameworks, and it has produced results of conceptual and practical relevance. A coherent and comprehensive review of the vast research activity concerning epidemic processes is presented, detailing the successful theoretical approaches as well as making their limits and assumptions clear. Physicists, mathematicians, epidemiologists, computer, and social scientists share a common interest in studying epidemic spreading and rely on similar models for the description of the diffusion of pathogens, knowledge, and innovation. For this reason, while focusing on the main results and the paradigmatic models in infectious disease modeling, the major results concerning generalized social contagion processes are also presented. Finally, the research activity at the forefront in the study of epidemic spreading in coevolving, coupled, and time-varying networks is reported.

  14. Environmental Factors Influencing Epidemic Cholera

    Science.gov (United States)

    Jutla, Antarpreet; Whitcombe, Elizabeth; Hasan, Nur; Haley, Bradd; Akanda, Ali; Huq, Anwar; Alam, Munir; Sack, R. Bradley; Colwell, Rita

    2013-01-01

    Cholera outbreak following the earthquake of 2010 in Haiti has reaffirmed that the disease is a major public health threat. Vibrio cholerae is autochthonous to aquatic environment, hence, it cannot be eradicated but hydroclimatology-based prediction and prevention is an achievable goal. Using data from the 1800s, we describe uniqueness in seasonality and mechanism of occurrence of cholera in the epidemic regions of Asia and Latin America. Epidemic regions are located near regional rivers and are characterized by sporadic outbreaks, which are likely to be initiated during episodes of prevailing warm air temperature with low river flows, creating favorable environmental conditions for growth of cholera bacteria. Heavy rainfall, through inundation or breakdown of sanitary infrastructure, accelerates interaction between contaminated water and human activities, resulting in an epidemic. This causal mechanism is markedly different from endemic cholera where tidal intrusion of seawater carrying bacteria from estuary to inland regions, results in outbreaks. PMID:23897993

  15. Networked SIS Epidemics With Awareness

    KAUST Repository

    Paarporn, Keith

    2017-07-20

    We study a susceptible-infected-susceptible epidemic process over a static contact network where the nodes have partial information about the epidemic state. They react by limiting their interactions with their neighbors when they believe the epidemic is currently prevalent. A node\\'s awareness is weighted by the fraction of infected neighbors in their social network, and a global broadcast of the fraction of infected nodes in the entire network. The dynamics of the benchmark (no awareness) and awareness models are described by discrete-time Markov chains, from which mean-field approximations (MFAs) are derived. The states of the MFA are interpreted as the nodes\\' probabilities of being infected. We show a sufficient condition for the existence of a

  16. Understanding Ebola: the 2014 epidemic.

    Science.gov (United States)

    Kaner, Jolie; Schaack, Sarah

    2016-09-13

    Near the end of 2013, an outbreak of Zaire ebolavirus (EBOV) began in Guinea, subsequently spreading to neighboring Liberia and Sierra Leone. As this epidemic grew, important public health questions emerged about how and why this outbreak was so different from previous episodes. This review provides a synthetic synopsis of the 2014-15 outbreak, with the aim of understanding its unprecedented spread. We present a summary of the history of previous epidemics, describe the structure and genetics of the ebolavirus, and review our current understanding of viral vectors and the latest treatment practices. We conclude with an analysis of the public health challenges epidemic responders faced and some of the lessons that could be applied to future outbreaks of Ebola or other viruses.

  17. Uso da medicação homeopática no tratamento da ceratoconjuntivite primaveril: resultados iniciais Treatment of vernal keratoconjunctivitis with homeopathic medicine: a preliminary report

    Directory of Open Access Journals (Sweden)

    Cláudio Maciel de Sena

    2003-01-01

    Full Text Available OBJETIVO: Apresentar os primeiros resultados do uso da Homeopatia entre os pacientes com conjuntivite primaveril, avaliados no Serviço de Córnea e Doenças Externas do Hospital São Geraldo. MÉTODOS: Foram incluídos no presente estudo 13 pacientes apresentando ceratoconjuntivite primaveril, examinados no período de janeiro de 1998 a dezembro de 1999. A idade média dos pacientes foi de 9,5 anos, sendo nove do sexo masculino e quatro do sexo feminino. Todos os pacientes já haviam feito uso de corticóide tópico antes da sua inclusão no estudo. Antes de iniciar o tratamento homeopático, todos os pacientes foram examinados por um dos autores, sendo acompanhados pelo mesmo médico, mensalmente até os seis meses e depois trimestralmente até completar um ano do tratamento homeopático. O tratamento homeopático foi realizado por meio de uma dose única, via oral, baseando-se na totalidade sintomática do paciente. RESULTADOS: A porcentagem de melhora dos sinais e sintomas, entre os pacientes, foi de: lacrimejamento e dor ocular 100%; secreção ocular 92%; sensação de corpo estranho 86%; prurido e fotofobia 84%; relatavam diminuição ou ausência do desconforto que a ceratoconjuntivite primaveril provocava nas suas atividades diárias 84%; nódulos de Trantas 62,5%; hiperemia conjuntival 61%; erosões epiteliais 58% e hipertrofia da papila tarsal 8%. CONCLUSÃO: Este estudo sugere efeito benéfico da medicação homeopática no tratamento da ceratoconjuntivite primaveril, com melhora dos sinais e sintomas da doença. Sugere-se a realização de estudo duplo-cego, com maior número de casos, para a confirmação desses resultados.PURPOSE: To present a preliminary report of homeopathic medicine in the treatment of vernal keratoconjunctivitis, at the Cornea service, of the São Geraldo Hospital. METHODS: Thirteen patients with vernal keratoconjunctivitis, examined from January 1998 to December 1999, were included in the present study

  18. Ceratoconjuntivite cicatricial bilateral associada a líquen plano: relato de caso Lichen planus leading to bilateral cicatrizing keratoconjunctivitis: case report

    Directory of Open Access Journals (Sweden)

    Camila Melo Gadelha Pereira Diniz

    2008-12-01

    Full Text Available Descrevemos um caso de ceratoconjuntivite cicatricial bilateral em uma paciente portadora de líquen plano e apresentamos revisão da literatura mundial sobre esse assunto. Cicatrização conjuntival, com formação de simbléfaro, olho seco, infiltração corneana, neovascularização e afinamento foram os sinais observados. Diagnóstico foi baseado nos achados clínicos e biópsia, após exclusão das causas típicas de ceratoconjuntivite cicatricial.To describe a case of bilateral cicatrizing keratoconjunctivitis in a patient with lichen planus and review the literature. Conjunctiva cicatrization with symblepharon formation, dry eye, corneal infiltration and neovascularization and thinning were the most observed prominent signs. Diagnosis was based on clinical findings and biopsy, after exclusion of typical causes of cicatricial keratoconjuntivitis.

  19. Guidelines for identifying suspect/counterfeit material

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    These guidelines are intended to assist users of products in identifying: substandard, misrepresented, or fraudulently marked items. The guidelines provide information about such topics as: precautions, inspection and testing, dispositioning identified items, installed inspection and reporting suspect/counterfeit materials. These guidelines apply to users who are developing procurement documents, product acceptance/verification methods, company procedures, work instructions, etc. The intent of these SM guidelines in relation to the Quality Assurance Program Description (QAPD) and implementing company Management Control Procedures is not to substitute or replace existing requirements, as defined in either the QAPD or company implementing instructions (Management Control Procedures). Instead, the guidelines are intended to provide a consolidated source of information addressing the issue of Suspect/Counterfeit materials. These guidelines provide an extensive suspect component listing and suspect indications listing. Users can quickly check their suspect items against the list of manufacturers products (i.e., type, LD. number, and nameplate information) by consulting either of these listings.

  20. Epidemic spreading on interconnected networks.

    Science.gov (United States)

    Saumell-Mendiola, Anna; Serrano, M Ángeles; Boguñá, Marián

    2012-08-01

    Many real networks are not isolated from each other but form networks of networks, often interrelated in nontrivial ways. Here, we analyze an epidemic spreading process taking place on top of two interconnected complex networks. We develop a heterogeneous mean-field approach that allows us to calculate the conditions for the emergence of an endemic state. Interestingly, a global endemic state may arise in the coupled system even though the epidemics is not able to propagate on each network separately and even when the number of coupling connections is small. Our analytic results are successfully confronted against large-scale numerical simulations.

  1. The narcissism epidemic is dead : Long live the narcissism epidemic

    NARCIS (Netherlands)

    Wetzel, Eunike; Brown, Anna; Hill, Patrick; Chung, J.M.H.; Robins, R.W.; Roberts, B.W.

    2017-01-01

    Are recent cohorts of college students more narcissistic than their predecessors? To address debates about the so-called “narcissism epidemic,” we used data from three cohorts of students (N1990s = 1,166; N2000s = 33,647; N2010s = 25,412) to test whether narcissism levels (overall and specific

  2. Interventions for suspected placenta praevia.

    Science.gov (United States)

    Neilson, J P

    2003-01-01

    . Available data should, however, encourage further work to address the safety of more conservative policies of hospitalisation for women with suspected placenta praevia, and the possible value of insertion of a cervical suture.

  3. Epidemic threshold in directed networks

    Science.gov (United States)

    Li, Cong; Wang, Huijuan; Van Mieghem, Piet

    2013-12-01

    Epidemics have so far been mostly studied in undirected networks. However, many real-world networks, such as the online social network Twitter and the world wide web, on which information, emotion, or malware spreads, are directed networks, composed of both unidirectional links and bidirectional links. We define the directionality ξ as the percentage of unidirectional links. The epidemic threshold τc for the susceptible-infected-susceptible (SIS) epidemic is lower bounded by 1/λ1 in directed networks, where λ1, also called the spectral radius, is the largest eigenvalue of the adjacency matrix. In this work, we propose two algorithms to generate directed networks with a given directionality ξ. The effect of ξ on the spectral radius λ1, principal eigenvector x1, spectral gap (λ1-λ2), and algebraic connectivity μN-1 is studied. Important findings are that the spectral radius λ1 decreases with the directionality ξ, whereas the spectral gap and the algebraic connectivity increase with the directionality ξ. The extent of the decrease of the spectral radius depends on both the degree distribution and the degree-degree correlation ρD. Hence, in directed networks, the epidemic threshold is larger and a random walk converges to its steady state faster than that in undirected networks with the same degree distribution.

  4. Epidemic Synchronization in Robotic Swarms

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Nielsen, Jens Frederik Dalsgaard; Ngo, Trung Dung

    2009-01-01

    Clock synchronization in swarms of networked mobile robots is studied in a probabilistic, epidemic framework. In this setting communication and synchonization is considered to be a randomized process, taking place at unplanned instants of geographical rendezvous between robots. In combination...... as an infinite-dimensional optimal controlproblem. Illustrative numerical examples are given and commented....

  5. Stochastic Processes in Epidemic Theory

    CERN Document Server

    Lefèvre, Claude; Picard, Philippe

    1990-01-01

    This collection of papers gives a representative cross-selectional view of recent developments in the field. After a survey paper by C. Lefèvre, 17 other research papers look at stochastic modeling of epidemics, both from a theoretical and a statistical point of view. Some look more specifically at a particular disease such as AIDS, malaria, schistosomiasis and diabetes.

  6. The First American Cocaine Epidemic.

    Science.gov (United States)

    Courtwright, David T.

    1991-01-01

    Discusses the wave of cocaine abuse that followed the drug's recommendation by the late nineteenth-century medical community as a cure all. Details drug addiction among ethnic and social groups at the turn of the century. Warns that drug epidemics have important social and legal consequences. Suggests legal pressure may alter the form of drug…

  7. Epidemic Synchronization in Robotic Swarms

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Nielsen, Jens Frederik Dalsgaard; Ngo, Trung Dung

    2009-01-01

    Clock synchronization in swarms of networked mobile robots is studied in a probabilistic, epidemic framework. In this setting communication and synchonization is considered to be a randomized process, taking place at unplanned instants of geographical rendezvous between robots. In combination wit...

  8. Epidemics in adaptive networks with community structure

    Science.gov (United States)

    Shaw, Leah; Tunc, Ilker

    2010-03-01

    Models for epidemic spread on static social networks do not account for changes in individuals' social interactions. Recent studies of adaptive networks have modeled avoidance behavior, as non-infected individuals try to avoid contact with infectives. Such models have not generally included realistic social structure. Here we study epidemic spread on an adaptive network with community structure. We model the effect of heterogeneous communities on infection levels and epidemic extinction. We also show how an epidemic can alter the community structure.

  9. Epidemics spreading in interconnected complex networks

    International Nuclear Information System (INIS)

    Wang, Y.; Xiao, G.

    2012-01-01

    We study epidemic spreading in two interconnected complex networks. It is found that in our model the epidemic threshold of the interconnected network is always lower than that in any of the two component networks. Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. Theoretical analysis and simulation results show that, generally speaking, the epidemic size is not significantly affected by the inter-network correlation. In interdependent networks which can be viewed as a special case of interconnected networks, however, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant. -- Highlights: ► We study epidemic spreading in two interconnected complex networks. ► The epidemic threshold is lower than that in any of the two networks. And Interconnection correlation has impacts on threshold and average outbreak size. ► Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. ► We demonstrated and proved that Interconnection correlation does not affect epidemic size significantly. ► In interdependent networks, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant.

  10. Epidemics spreading in interconnected complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Institute of High Performance Computing, Agency for Science, Technology and Research (A-STAR), Singapore 138632 (Singapore); Xiao, G., E-mail: egxxiao@ntu.edu.sg [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2012-09-03

    We study epidemic spreading in two interconnected complex networks. It is found that in our model the epidemic threshold of the interconnected network is always lower than that in any of the two component networks. Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. Theoretical analysis and simulation results show that, generally speaking, the epidemic size is not significantly affected by the inter-network correlation. In interdependent networks which can be viewed as a special case of interconnected networks, however, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant. -- Highlights: ► We study epidemic spreading in two interconnected complex networks. ► The epidemic threshold is lower than that in any of the two networks. And Interconnection correlation has impacts on threshold and average outbreak size. ► Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. ► We demonstrated and proved that Interconnection correlation does not affect epidemic size significantly. ► In interdependent networks, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant.

  11. First isolation of dengue virus from the 2010 epidemic in Nepal.

    Science.gov (United States)

    Pandey, Basu D; Nabeshima, Takeshi; Pandey, Kishor; Rajendra, Saroj P; Shah, Yogendra; Adhikari, Bal R; Gupta, Govinda; Gautam, Ishan; Tun, Mya M N; Uchida, Reo; Shrestha, Mahendra; Kurane, Ichiro; Morita, Kouichi

    2013-09-01

    Dengue is an emerging disease in Nepal and was first observed as an outbreak in nine lowland districts in 2006. In 2010, however, a large epidemic of dengue occurred with 4,529 suspected and 917 serologically-confirmed cases and five deaths reported in government hospitals in Nepal. The collection of demographic information was performed along with an entomological survey and clinical evaluation of the patients. A total of 280 serum samples were collected from suspected dengue patients. These samples were subjected to routine laboratory investigations and IgM-capture ELISA for dengue serological identification, and 160 acute serum samples were used for virus isolation, RT-PCR, sequencing and phylogenetic analysis. The results showed that affected patients were predominately adults, and that 10% of the cases were classified as dengue haemorrhagic fever/ dengue shock syndrome. The genetic characterization of dengue viruses isolated from patients in four major outbreak areas of Nepal suggests that the DENV-1 strain was responsible for the 2010 epidemic. Entomological studies identified Aedes aegypti in all epidemic areas. All viruses belonged to a monophyletic single clade which is phylogenetically close to Indian viruses. The dengue epidemic started in the lowlands and expanded to the highland areas. To our knowledge, this is the first dengue isolation and genetic characterization reported from Nepal.

  12. Descriptive epidemiology of typhoid fever during an epidemic in Harare, Zimbabwe, 2012.

    Science.gov (United States)

    Polonsky, Jonathan A; Martínez-Pino, Isabel; Nackers, Fabienne; Chonzi, Prosper; Manangazira, Portia; Van Herp, Michel; Maes, Peter; Porten, Klaudia; Luquero, Francisco J

    2014-01-01

    Typhoid fever remains a significant public health problem in developing countries. In October 2011, a typhoid fever epidemic was declared in Harare, Zimbabwe - the fourth enteric infection epidemic since 2008. To orient control activities, we described the epidemiology and spatiotemporal clustering of the epidemic in Dzivaresekwa and Kuwadzana, the two most affected suburbs of Harare. A typhoid fever case-patient register was analysed to describe the epidemic. To explore clustering, we constructed a dataset comprising GPS coordinates of case-patient residences and randomly sampled residential locations (spatial controls). The scale and significance of clustering was explored with Ripley K functions. Cluster locations were determined by a random labelling technique and confirmed using Kulldorff's spatial scan statistic. We analysed data from 2570 confirmed and suspected case-patients, and found significant spatiotemporal clustering of typhoid fever in two non-overlapping areas, which appeared to be linked to environmental sources. Peak relative risk was more than six times greater than in areas lying outside the cluster ranges. Clusters were identified in similar geographical ranges by both random labelling and Kulldorff's spatial scan statistic. The spatial scale at which typhoid fever clustered was highly localised, with significant clustering at distances up to 4.5 km and peak levels at approximately 3.5 km. The epicentre of infection transmission shifted from one cluster to the other during the course of the epidemic. This study demonstrated highly localised clustering of typhoid fever during an epidemic in an urban African setting, and highlights the importance of spatiotemporal analysis for making timely decisions about targetting prevention and control activities and reinforcing treatment during epidemics. This approach should be integrated into existing surveillance systems to facilitate early detection of epidemics and identify their spatial range.

  13. Handbook for Response to Suspect Radioactive Materials

    International Nuclear Information System (INIS)

    Cliff, William C.; Pappas, Richard A.; Arthur, Richard J.

    2005-01-01

    This document provides response actions to be performed following the initial port, airport, or border crossing discovery of material that is suspected of being radioactive. The purpose of this guide is to provide actions appropriate for handling radioactive material

  14. Multiple routes transmitted epidemics on multiplex networks

    International Nuclear Information System (INIS)

    Zhao, Dawei; Li, Lixiang; Peng, Haipeng; Luo, Qun; Yang, Yixian

    2014-01-01

    This letter investigates the multiple routes transmitted epidemic process on multiplex networks. We propose detailed theoretical analysis that allows us to accurately calculate the epidemic threshold and outbreak size. It is found that the epidemic can spread across the multiplex network even if all the network layers are well below their respective epidemic thresholds. Strong positive degree–degree correlation of nodes in multiplex network could lead to a much lower epidemic threshold and a relatively smaller outbreak size. However, the average similarity of neighbors from different layers of nodes has no obvious effect on the epidemic threshold and outbreak size. -- Highlights: •We studies multiple routes transmitted epidemic process on multiplex networks. •SIR model and bond percolation theory are used to analyze the epidemic processes. •We derive equations to accurately calculate the epidemic threshold and outbreak size. •ASN has no effect on the epidemic threshold and outbreak size. •Strong positive DDC leads to a lower epidemic threshold and a smaller outbreak size.

  15. Multiple routes transmitted epidemics on multiplex networks

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dawei [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Shandong Provincial Key Laboratory of Computer Network, Shandong Computer Science Center, Jinan 250014 (China); Li, Lixiang [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Peng, Haipeng, E-mail: penghaipeng@bupt.edu.cn [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Luo, Qun; Yang, Yixian [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

    2014-02-01

    This letter investigates the multiple routes transmitted epidemic process on multiplex networks. We propose detailed theoretical analysis that allows us to accurately calculate the epidemic threshold and outbreak size. It is found that the epidemic can spread across the multiplex network even if all the network layers are well below their respective epidemic thresholds. Strong positive degree–degree correlation of nodes in multiplex network could lead to a much lower epidemic threshold and a relatively smaller outbreak size. However, the average similarity of neighbors from different layers of nodes has no obvious effect on the epidemic threshold and outbreak size. -- Highlights: •We studies multiple routes transmitted epidemic process on multiplex networks. •SIR model and bond percolation theory are used to analyze the epidemic processes. •We derive equations to accurately calculate the epidemic threshold and outbreak size. •ASN has no effect on the epidemic threshold and outbreak size. •Strong positive DDC leads to a lower epidemic threshold and a smaller outbreak size.

  16. Epidemic processes in complex networks

    OpenAIRE

    Pastor Satorras, Romualdo; Castellano, Claudio; Van Mieghem, Piet; Vespignani, Alessandro

    2015-01-01

    In recent years the research community has accumulated overwhelming evidence for the emergence of complex and heterogeneous connectivity patterns in a wide range of biological and sociotechnical systems. The complex properties of real-world networks have a profound impact on the behavior of equilibrium and nonequilibrium phenomena occurring in various systems, and the study of epidemic spreading is central to our understanding of the unfolding of dynamical processes in complex networks. The t...

  17. Measles epidemic in Brazil in the post-elimination period: Coordinated response and containment strategies.

    Science.gov (United States)

    Lemos, Daniele Rocha Queiroz; Franco, Aidée Ramirez; de Sá Roriz, Maria Lúcia Feitosa; Carneiro, Ana Karine Borges; de Oliveira Garcia, Márcio Henrique; de Souza, Fábia Lidiana; Duron Andino, Regina; de Góes Cavalcanti, Luciano Pamplona

    2017-03-23

    The measles virus circulation was halted in Brazil in 2001 and the country has a routine vaccination coverage against measles, mumps and rubella higher than 95%. In Ceará, the last confirmed case was in 1999. This article describes the strategies adopted and the effectiveness of surveillance and control measures implemented during a measles epidemic in the post-elimination period. The epidemic started in December 2013 and lasted 20 months, reaching 38 cities and 1,052 confirmed cases. The D8 genotype was identified. More than 50,000 samples were tested for measles and 86.4% of the confirmed cases had a laboratory diagnosis. The beginning of an campaign vaccination was delayed in part by the availability of vaccine. The classic control measures were not enough to control the epidemic. The creation of a committee of experts, the agreement signed between managers of the three spheres of government, the conducting of an institutional active search of suspected cases, vaccination door to door at alternative times, the use of micro planning, a broad advertising campaign at local media and technical operative support contributed to containing the epidemic. It is important to recognize the possibility of epidemics at this stage of post-elimination and prepare a sensitive surveillance system for timely response. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Cholera: an overview with reference to the Yemen epidemic.

    Science.gov (United States)

    Rabaan, Ali A

    2018-06-22

    Cholera is a secretory diarrhoeal disease caused by infection with Vibrio cholerae, primarily the V. cholerae O1 El Tor biotype. There are approximately 2.9 million cases in 69 endemic countries annually, resulting in 95 000 deaths. Cholera is associated with poor infrastructure and lack of access to sanitation and clean drinking water. The current cholera epidemic in Yemen, linked to spread of V. cholerae O1 (Ogawa serotype), is associated with the ongoing war. This has devastated infrastructure and health services. The World Health Organization had estimated that 172 286 suspected cases arose between 27th April and 19th June 2017, including 1170 deaths. While there are three oral cholera vaccines prequalified by the World Health Organization, there are issues surrounding vaccination campaigns in conflict situations, exacerbated by external factors such as a global vaccine shortage. Major movements of people complicates surveillance and administration of double doses of vaccines. Cholera therapy mainly depends on rehydration, with use of antibiotics in more severe infections. Concerns have arisen about the rise of antibiotic resistance in cholera, due to mobile genetic elements. In this review, we give an overview of cholera epidemiology, virulence, antibiotic resistance, therapy and vaccines, in the light of the ongoing epidemic in Yemen.

  19. Contact allergy epidemics and their controls

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Johansen, Jeanne Duus; Menné, Torkil

    2007-01-01

    Contact dermatitis can be severe and lead to sick leave as well as significant healthcare expenses. The aim of this review is to present the published knowledge on 6 historical epidemics of contact allergy to apply this knowledge on the prevention and control of future contact allergy epidemics. ...... to prevent contact allergy epidemics. It is essential that dermatologist, scientists, administrators, and consumers organize and structure known methods to accelerate the control of emerging contact allergens....

  20. Can rewiring strategy control the epidemic spreading?

    Science.gov (United States)

    Dong, Chao; Yin, Qiuju; Liu, Wenyang; Yan, Zhijun; Shi, Tianyu

    2015-11-01

    Relation existed in the social contact network can affect individuals' behaviors greatly. Considering the diversity of relation intimacy among network nodes, an epidemic propagation model is proposed by incorporating the link-breaking threshold, which is normally neglected in the rewiring strategy. The impact of rewiring strategy on the epidemic spreading in the weighted adaptive network is explored. The results show that the rewiring strategy cannot always control the epidemic prevalence, especially when the link-breaking threshold is low. Meanwhile, as well as strong links, weak links also play a significant role on epidemic spreading.

  1. Suspected Child Maltreatment: Recognize and Respond

    Science.gov (United States)

    Kemple, Kristen Mary; Kim, Hae Kyoung

    2011-01-01

    Early childhood educators spend extensive amounts of time with young children, so they are often the first adults to notice signs that a child may be abused or neglected. All educators are required by law to report suspected maltreatment, and can play an important role in preventing and responding to abuse and neglect of young children. What is…

  2. Suspecting Neurological Dysfunction From E Mail Messages ...

    African Journals Online (AJOL)

    A non medical person suspected and confirmed neurological dysfunction in an individual, based only on e mail messages sent by the individual. With email communication becoming rampant “peculiar” email messages may raise the suspicion of neurological dysfunction. Organic pathology explaining the abnormal email ...

  3. The Diabetes Epidemic in Korea

    Directory of Open Access Journals (Sweden)

    Junghyun Noh

    2016-09-01

    Full Text Available Diabetes is one of the foremost public health issues worldwide that can lead to complications in many organ systems, and has become a significant cause of morbidity and mortality in Korea. According to data from the National Health Insurance Service (NHIS, about 2.7 million Koreans (8.0% aged 30 years or older had type 2 diabetes mellitus (T2DM in 2013. The prevalence of T2DM increased with age and rose from 5.6% in 2006 to 8.0% in 2013. Using data based on The Health Screening Service of the NHIS, 25% of Korean adults were reported to have prediabetes in 2013. The prevalence of an impaired fasting glucose tended to increase over time from 21.5% in 2006 to 25.0% in 2013. Even though nationwide health screening has been regularly conducted as a public service, the proportion of undiagnosed cases of diabetes was still reported to be on the higher side in the latest study. Based on the results of these epidemic studies, further actions will be needed to effectively implement lifestyle changes on a social level and increase measures for the early detection of diabetes to stem the tide of the epidemic.

  4. Epidemic Network Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Katsikas, Dimitrios; Fagertun, Anna Manolova

    2013-01-01

    This paper presents a failure propagation model for transport networks which are affected by epidemic failures. The network is controlled using the GMPLS protocol suite. The Susceptible Infected Disabled (SID) epidemic model is investigated and new signaling functionality of GMPLS to support...

  5. Household demographic determinants of Ebola epidemic risk.

    Science.gov (United States)

    Adams, Ben

    2016-03-07

    A salient characteristic of Ebola, and some other infectious diseases such as Tuberculosis, is intense transmission among small groups of cohabitants and relatively limited indiscriminate transmission in the wider population. Here we consider a mathematical model for an Ebola epidemic in a population structured into households of equal size. We show that household size, a fundamental demographic unit, is a critical factor that determines the vulnerability of a community to epidemics, and the effort required to control them. Our analysis is based on the household reproduction number, but we also consider the basic reproduction number, intrinsic growth rate and final epidemic size. We show that, when other epidemiological parameters are kept the same, all of these quantifications of epidemic growth and size are increased by larger households and more intense within-household transmission. We go on to model epidemic control by case detection and isolation followed by household quarantine. We show that, if household quarantine is ineffective, the critical probability with which cases must be detected to halt an epidemic increases significantly with each increment in household size and may be a very challenging target for communities composed of large households. Effective quarantine may, however, mitigate the detrimental impact of large household sizes. We conclude that communities composed of large households are fundamentally more vulnerable to epidemics of infectious diseases primarily transmitted by close contact, and any assessment of control strategies for these epidemics should take into account the demographic structure of the population. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Malaria epidemic and drug resistance, Djibouti.

    Science.gov (United States)

    Rogier, Christophe; Pradines, Bruno; Bogreau, H; Koeck, Jean-Louis; Kamil, Mohamed-Ali; Mercereau-Puijalon, Odile

    2005-02-01

    Analysis of Plasmodium falciparum isolates collected before, during, and after a 1999 malaria epidemic in Djibouti shows that, despite a high prevalence of resistance to chloroquine, the epidemic cannot be attributed to a sudden increase in drug resistance of local parasite populations.

  7. Epidemics in interconnected small-world networks

    NARCIS (Netherlands)

    Liu, M.; Li, D.; Qin, P.; Liu, C.; Wang, H.; Wang, F.

    2015-01-01

    Networks can be used to describe the interconnections among individuals, which play an important role in the spread of disease. Although the small-world effect has been found to have a significant impact on epidemics in single networks, the small-world effect on epidemics in interconnected networks

  8. Stemming the obesity epidemic : a tantalizing prospect

    NARCIS (Netherlands)

    Veerman, J Lennert; Barendregt, Jan J; van Beeck, Ed F; Seidell, Jacob C; Mackenbach, Johan P

    OBJECTIVE: Obesity is a growing problem worldwide, but there are no good methods to assess the future course of the epidemic and the potential influence of interventions. We explore the behavior change needed to stop the obesity epidemic in the U.S. RESEARCH METHODS AND PROCEDURES: We modeled the

  9. Inferring epidemic contact structure from phylogenetic trees.

    Directory of Open Access Journals (Sweden)

    Gabriel E Leventhal

    Full Text Available Contact structure is believed to have a large impact on epidemic spreading and consequently using networks to model such contact structure continues to gain interest in epidemiology. However, detailed knowledge of the exact contact structure underlying real epidemics is limited. Here we address the question whether the structure of the contact network leaves a detectable genetic fingerprint in the pathogen population. To this end we compare phylogenies generated by disease outbreaks in simulated populations with different types of contact networks. We find that the shape of these phylogenies strongly depends on contact structure. In particular, measures of tree imbalance allow us to quantify to what extent the contact structure underlying an epidemic deviates from a null model contact network and illustrate this in the case of random mixing. Using a phylogeny from the Swiss HIV epidemic, we show that this epidemic has a significantly more unbalanced tree than would be expected from random mixing.

  10. Epidemics in interconnected small-world networks.

    Science.gov (United States)

    Liu, Meng; Li, Daqing; Qin, Pengju; Liu, Chaoran; Wang, Huijuan; Wang, Feilong

    2015-01-01

    Networks can be used to describe the interconnections among individuals, which play an important role in the spread of disease. Although the small-world effect has been found to have a significant impact on epidemics in single networks, the small-world effect on epidemics in interconnected networks has rarely been considered. Here, we study the susceptible-infected-susceptible (SIS) model of epidemic spreading in a system comprising two interconnected small-world networks. We find that the epidemic threshold in such networks decreases when the rewiring probability of the component small-world networks increases. When the infection rate is low, the rewiring probability affects the global steady-state infection density, whereas when the infection rate is high, the infection density is insensitive to the rewiring probability. Moreover, epidemics in interconnected small-world networks are found to spread at different velocities that depend on the rewiring probability.

  11. Epidemics in interconnected small-world networks.

    Directory of Open Access Journals (Sweden)

    Meng Liu

    Full Text Available Networks can be used to describe the interconnections among individuals, which play an important role in the spread of disease. Although the small-world effect has been found to have a significant impact on epidemics in single networks, the small-world effect on epidemics in interconnected networks has rarely been considered. Here, we study the susceptible-infected-susceptible (SIS model of epidemic spreading in a system comprising two interconnected small-world networks. We find that the epidemic threshold in such networks decreases when the rewiring probability of the component small-world networks increases. When the infection rate is low, the rewiring probability affects the global steady-state infection density, whereas when the infection rate is high, the infection density is insensitive to the rewiring probability. Moreover, epidemics in interconnected small-world networks are found to spread at different velocities that depend on the rewiring probability.

  12. Cooperative epidemics on multiplex networks

    Science.gov (United States)

    Azimi-Tafreshi, N.

    2016-04-01

    The spread of one disease, in some cases, can stimulate the spreading of another infectious disease. Here, we treat analytically a symmetric coinfection model for spreading of two diseases on a two-layer multiplex network. We allow layer overlapping, but we assume that each layer is random and locally loopless. Infection with one of the diseases increases the probability of getting infected with the other. Using the generating function method, we calculate exactly the fraction of individuals infected with both diseases (so-called coinfected clusters) in the stationary state, as well as the epidemic spreading thresholds and the phase diagram of the model. With increasing cooperation, we observe a tricritical point and the type of transition changes from continuous to hybrid. Finally, we compare the coinfected clusters in the case of cooperating diseases with the so-called "viable" clusters in networks with dependencies.

  13. Epidemic Survivability: Characterizing Networks Under Epidemic-like Failure Propagation Scenarios

    DEFF Research Database (Denmark)

    Manzano, Marc; Calle, Eusebi; Ripoll, Jordi

    2013-01-01

    Epidemics theory has been used in different contexts in order to describe the propagation of diseases, human interactions or natural phenomena. In computer science, virus spreading has been also characterized using epidemic models. Although in the past the use of epidemic models...... in telecommunication networks has not been extensively considered, nowadays, with the increasing computation capacity and complexity of operating systems of modern network devices (routers, switches, etc.), the study of possible epidemic-like failure scenarios must be taken into account. When epidemics occur......, such as in other multiple failure scenarios, identifying the level of vulnerability offered by a network is one of the main challenges. In this paper, we present epidemic survivability, a new network measure that describes the vulnerability of each node of a network under a specific epidemic intensity. Moreover...

  14. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania

    OpenAIRE

    Mweya, Clement N.; Kimera, Sharadhuli I.; Mellau, Lesakit S. B.; Mboera, Leonard E. G.

    2015-01-01

    Background: Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. Objective: To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. Methods: A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mos...

  15. Deciphering the Origin of the 2012 Cholera Epidemic in Guinea by Integrating Epidemiological and Molecular Analyses

    Science.gov (United States)

    Rebaudet, Stanislas; Mengel, Martin A.; Koivogui, Lamine; Moore, Sandra; Mutreja, Ankur; Kande, Yacouba; Yattara, Ousmane; Sarr Keita, Véronique; Njanpop-Lafourcade, Berthe-Marie; Fournier, Pierre-Edouard; Garnotel, Eric; Keita, Sakoba; Piarroux, Renaud

    2014-01-01

    Cholera is typically considered endemic in West Africa, especially in the Republic of Guinea. However, a three-year lull period was observed from 2009 to 2011, before a new epidemic struck the country in 2012, which was officially responsible for 7,350 suspected cases and 133 deaths. To determine whether cholera re-emerged from the aquatic environment or was rather imported due to human migration, a comprehensive epidemiological and molecular survey was conducted. A spatiotemporal analysis of the national case databases established Kaback Island, located off the southern coast of Guinea, as the initial focus of the epidemic in early February. According to the field investigations, the index case was found to be a fisherman who had recently arrived from a coastal district of neighboring Sierra Leone, where a cholera outbreak had recently occurred. MLVA-based genotype mapping of 38 clinical Vibrio cholerae O1 El Tor isolates sampled throughout the epidemic demonstrated a progressive genetic diversification of the strains from a single genotype isolated on Kaback Island in February, which correlated with spatial epidemic spread. Whole-genome sequencing characterized this strain as an “atypical” El Tor variant. Furthermore, genome-wide SNP-based phylogeny analysis grouped the Guinean strain into a new clade of the third wave of the seventh pandemic, distinct from previously analyzed African strains and directly related to a Bangladeshi isolate. Overall, these results highly suggest that the Guinean 2012 epidemic was caused by a V. cholerae clone that was likely imported from Sierra Leone by an infected individual. These results indicate the importance of promoting the cross-border identification and surveillance of mobile and vulnerable populations, including fishermen, to prevent, detect and control future epidemics in the region. Comprehensive epidemiological investigations should be expanded to better understand cholera dynamics and improve disease control

  16. Suspects in criminal investigations of rape

    Directory of Open Access Journals (Sweden)

    Marinković Darko

    2014-01-01

    Full Text Available Investigations of sexual assaults mostly focus on victims and their credibility, which may cause lack of firm evidence in relation to suspects. Given the fact that the criminal offence of rape is characterised by a high incidence of false reports and accusations, frequently indicating specific persons as the perpetrators, certain caution is necessary in the investigation in order to avoid false accusations and/or convictions. As regards the personality of the rapist and motives for committing a forcible sexual act, certain types or rather certain categories of perpetrators can be distinguished, although it should be noted that a large number of rapists do not belong to one category only, but rather combine characteristics of several different types. During a criminal investigation it is of vital importance to differentiate between a rape as a surprise attack and a rape as abuse of trust, as they are compatible with the nature of the suspect's defence. The suspect shall be subjected to a forensic examination in the course of the investigation in order to find traces which prove vaginal, anal or oral penetration, coerced sexual intercourse and identity of the rapist. While conducting an interrogation of a suspected rapist, a crime investigating officer shall use either factual or emotional approach to his interviewee, depending on his psychological and motivational characteristics. In this regard, the factual approach is believed to be more efficient with anger rapists and sadistic rapists, whereas the compassionate approach gives good results with the gentlemen-rapists and partly with the power asserting rapists.

  17. Magnetic resonance angiography in suspected cerebral vasculitis

    International Nuclear Information System (INIS)

    Demaerel, Philippe; De Ruyter, Nele; Wilms, Guido; Maes, Frederik; Velghe, Beatrijs

    2004-01-01

    The purpose of this study was to determine the technical capacity and diagnostic accuracy of 3D time-of-flight magnetic resonance angiography (MRA) in suspected cerebral vasculitis in a retrospective analysis of MRA and digital subtraction angiography (DSA) in 14 young patients with clinical and/or radiological suspicion of cerebral vasculitis. A total of nine arteries were evaluated in each patient. Consensus review of DSA by three observers was the reference standard. The sensitivity for detecting a stenosis varied from 62 to 79% for MRA and from 76 to 94% for DSA, depending on the observer. The specificity for detecting a stenosis varied from 83 to 87% for MRA and from 83 to 97% for DSA. Using the criterion ''more than two stenoses in at least two separate vascular distributions'' to consider the examination as being true positive, the false-positive rates for MRA and DSA were comparable. MRA plays a role as the first angiographical examination in the diagnostic work-up of suspected cerebral vasculitis. When more than two stenoses in at least two separate vascular distributions are depicted on MRA, DSA is not expected to add a significant diagnostic contribution in a patient with suspected cerebral vasculitis. DSA remains necessary when MRA is normal or when less than three stenoses are seen. (orig.)

  18. Magnetic resonance angiography in suspected cerebral vasculitis

    Energy Technology Data Exchange (ETDEWEB)

    Demaerel, Philippe; De Ruyter, Nele; Wilms, Guido [Department of Radiology, Universitair Ziekenhuis, KU Leuven, 3000, Leuven (Belgium); Maes, Frederik [Department of Medical Imaging Computing, Universitair Ziekenhuis, KU Leuven, 3000, Leuven (Belgium); Velghe, Beatrijs [Department of Radiology, Ziekenhuis Oost-Limburg, Schiepse Bos 6, 3600, Genk (Belgium)

    2004-06-01

    The purpose of this study was to determine the technical capacity and diagnostic accuracy of 3D time-of-flight magnetic resonance angiography (MRA) in suspected cerebral vasculitis in a retrospective analysis of MRA and digital subtraction angiography (DSA) in 14 young patients with clinical and/or radiological suspicion of cerebral vasculitis. A total of nine arteries were evaluated in each patient. Consensus review of DSA by three observers was the reference standard. The sensitivity for detecting a stenosis varied from 62 to 79% for MRA and from 76 to 94% for DSA, depending on the observer. The specificity for detecting a stenosis varied from 83 to 87% for MRA and from 83 to 97% for DSA. Using the criterion ''more than two stenoses in at least two separate vascular distributions'' to consider the examination as being true positive, the false-positive rates for MRA and DSA were comparable. MRA plays a role as the first angiographical examination in the diagnostic work-up of suspected cerebral vasculitis. When more than two stenoses in at least two separate vascular distributions are depicted on MRA, DSA is not expected to add a significant diagnostic contribution in a patient with suspected cerebral vasculitis. DSA remains necessary when MRA is normal or when less than three stenoses are seen. (orig.)

  19. Histologic characteristics and local cellular immunity of the gland of the third eyelid after topical ophthalmic administration of 2% cyclosporine for treatment of dogs with keratoconjunctivitis sicca.

    Science.gov (United States)

    Izci, Celal; Celik, Ilhami; Alkan, Fahrettin; Ogurtan, Zeki; Ceylan, Cengiz; Sur, Emrah; Ozkan, Yasemin

    2002-05-01

    To evaluate the efficacy of topical administration of a 2% solution of cyclosporine (CsA) for treatment of dogs with keratoconjunctivitis sicca (KCS) and to correlate results with histopathologic characteristics and local cellular immunity of the gland of the third eyelid. 24 dogs with bilateral KCS. Lacrimal secretion was measured, using Schirmer tear test (STT) strips. Leukocyte and T-lymphocyte subsets were determined in blood samples. Histopathologic changes as well as CD4+, CD8+, and alpha-naphthyl-acetate esterase-positive (ANAE+) lymphocytes were evaluated. Clinical signs resolved at the end of 1 month in conjunction with significantly increased STT values, compared with baseline values. Fifteen and 30 days after discontinuation of CsA treatment, a decrease was observed in STT values in both eyes; however, only values for the right eye were significantly different. There was a significant decrease in the number of lymphocytes and ANAE+ lymphocytes 15 and 30 days after discontinuation of CsA treatment, compared with baseline values. Differences were not observed in number of CD4+ lymphocytes among treatment groups. However, there was a significant decrease in number of CD8+ lymphocytes with reversal of the CD4+:CD8+ in both eyes after CsA treatment for 30 days, compared with the control group. Increased secretory activity and decreased lymphocyte infiltration were characteristic histopathologic findings. Topical administration of a 2% solution of CsA was effective for the treatment of dogs with KCS. Strict follow-up monitoring is required after the cessation of treatment because of the possibility of recurrence of KCS.

  20. Pre-admission antibiotics for suspected cases of meningococcal disease.

    Science.gov (United States)

    Sudarsanam, Thambu D; Rupali, Priscilla; Tharyan, Prathap; Abraham, Ooriapadickal Cherian; Thomas, Kurien

    2017-06-14

    Meningococcal disease can lead to death or disability within hours after onset. Pre-admission antibiotics aim to reduce the risk of serious disease and death by preventing delays in starting therapy before confirmation of the diagnosis. To study the effectiveness and safety of pre-admission antibiotics versus no pre-admission antibiotics or placebo, and different pre-admission antibiotic regimens in decreasing mortality, clinical failure, and morbidity in people suspected of meningococcal disease. We searched CENTRAL (6 January 2017), MEDLINE (1966 to 6 January 2017), Embase (1980 to 6 January 2017), Web of Science (1985 to 6 January 2017), LILACS (1982 to 6 January 2017), and prospective trial registries to January 2017. We previously searched CAB Abstracts from 1985 to June 2015, but did not update this search in January 2017. Randomised controlled trials (RCTs) or quasi-RCTs comparing antibiotics versus placebo or no intervention, in people with suspected meningococcal infection, or different antibiotics administered before admission to hospital or confirmation of the diagnosis. Two review authors independently assessed trial quality and extracted data from the search results. We calculated the risk ratio (RR) and 95% confidence interval (CI) for dichotomous data. We included only one trial and so did not perform data synthesis. We assessed the overall quality of the evidence using the GRADE approach. We found no RCTs comparing pre-admission antibiotics versus no pre-admission antibiotics or placebo. We included one open-label, non-inferiority RCT with 510 participants, conducted during an epidemic in Niger, evaluating a single dose of intramuscular ceftriaxone versus a single dose of intramuscular long-acting (oily) chloramphenicol. Ceftriaxone was not inferior to chloramphenicol in reducing mortality (RR 1.21, 95% CI 0.57 to 2.56; N = 503; 308 confirmed meningococcal meningitis; 26 deaths; moderate-quality evidence), clinical failures (RR 0.83, 95% CI 0.32 to

  1. Using Phenomenological Models to Characterize Transmissibility and Forecast Patterns and Final Burden of Zika Epidemics

    DEFF Research Database (Denmark)

    Chowell, Gerardo; Hincapie-Palacio, Doracelly; Ospina, Juan

    2016-01-01

    BACKGROUND: The World Health Organization declared the ongoing Zika virus (ZIKV) epidemic in the Americas a Public Health Emergency of International Concern on February 1, 2016. ZIKV disease in humans is characterized by a "dengue-like" syndrome including febrile illness and rash. However, ZIKV...... impact. METHODS: We obtained daily counts of suspected Zika cases by date of symptoms onset from the Secretary of Health of Antioquia, Colombia during January-April 2016. We calibrated the generalized Richards model, a phenomenological model that accommodates a variety of early exponential and sub...

  2. Percolation and epidemics in random clustered networks

    Science.gov (United States)

    Miller, Joel C.

    2009-08-01

    The social networks that infectious diseases spread along are typically clustered. Because of the close relation between percolation and epidemic spread, the behavior of percolation in such networks gives insight into infectious disease dynamics. A number of authors have studied percolation or epidemics in clustered networks, but the networks often contain preferential contacts in high degree nodes. We introduce a class of random clustered networks and a class of random unclustered networks with the same preferential mixing. Percolation in the clustered networks reduces the component sizes and increases the epidemic threshold compared to the unclustered networks.

  3. Predicting extinction rates in stochastic epidemic models

    International Nuclear Information System (INIS)

    Schwartz, Ira B; Billings, Lora; Dykman, Mark; Landsman, Alexandra

    2009-01-01

    We investigate the stochastic extinction processes in a class of epidemic models. Motivated by the process of natural disease extinction in epidemics, we examine the rate of extinction as a function of disease spread. We show that the effective entropic barrier for extinction in a susceptible–infected–susceptible epidemic model displays scaling with the distance to the bifurcation point, with an unusual critical exponent. We make a direct comparison between predictions and numerical simulations. We also consider the effect of non-Gaussian vaccine schedules, and show numerically how the extinction process may be enhanced when the vaccine schedules are Poisson distributed

  4. Vascular factors in suspected normal pressure hydrocephalus

    Science.gov (United States)

    Agerskov, Simon; Rabiei, Katrin; Marlow, Thomas; Jensen, Christer; Guo, Xinxin; Kern, Silke; Wikkelsø, Carsten; Skoog, Ingmar

    2016-01-01

    Objective: We examined clinical and imaging findings of suspected idiopathic normal pressure hydrocephalus (iNPH) in relation to vascular risk factors and white matter lesions (WMLs), using a nested case-control design in a representative, population-based sample. Methods: From a population-based sample, 1,235 persons aged 70 years or older were examined with CT of the brain between 1986 and 2000. We identified 55 persons with hydrocephalic ventricular enlargement, i.e., radiologic findings consistent with iNPH. Among these, 26 had clinical signs that fulfilled international guideline criteria for probable iNPH. These cases were labeled suspected iNPH. Each case was matched to 5 controls from the same sample, based on age, sex, and study cohort. Data on risk factors were obtained from clinical examinations and the Swedish Hospital Discharge Register. History of hypertension, diabetes mellitus (DM), smoking, overweight, history of coronary artery disease, stroke/TIA, and WMLs on CT were examined. Risk factors associated with iNPH with a p value <0.1 in χ2 tests were included in conditional logistic regression models. Results: In the regression analyses, suspected iNPH was related to moderate to severe WMLs (odds ratio [OR] 5.2; 95% confidence interval [CI]: 1.5–17.6), while hydrocephalic ventricular enlargement was related to hypertension (OR 2.7; 95% CI: 1.1–6.8), moderate to severe WMLs (OR 6.5; 95% CI: 2.1–20.3), and DM (OR 4.3; 95% CI: 1.1–16.3). Conclusions: Hypertension, WMLs, and DM were related to clinical and imaging features of iNPH, suggesting that vascular mechanisms are involved in the pathophysiology. These findings might have implications for understanding disease mechanisms in iNPH and possibly prevention. PMID:26773072

  5. Nuclear Pedigree Criteria of Suspected HNPCC

    Directory of Open Access Journals (Sweden)

    Kładny Józef

    2003-01-01

    Full Text Available Abstract The criteria for the diagnosis of HNPCC established by the ICG-HNPCC are very restrictive as they do not allow for the diagnosis of a large number of "suspected HNPCC" cases - these are families which do no fulfill the strict diagnostic "Amsterdam criteria", but do present with several pedigree and clinical features characteristic for HNPCC. Several series of families suspected of harboring germline mutations in DNA mismatch repair genes have been studied for germline changes in DNA mismatch repair genes and a mutation rate of somewhere between 8-60% was found. Therefore a subgroup of members of the ICG-HNPCC has been working on pedigree/clinical diagnostic criteria for suspected HNPCC. Materials and methods Part I The study was based on two series of colorectal cancer (CRC cases: 1 HNPCC - this group comprised 190 patients affected by CRC from randomly selected families which fulfilled the Amsterdam II criteria registered in Düsseldorf, Germany (102 cases of CRC, Denmark (18 CRCs, Leiden, Holland (23 CRCs and Szczecin, Poland (47 CRCs. 2 Consecutive CRCs - this group comprised 629 (78.0% of 806 individuals with CRC diagnosed in 1991-1997 in the city of Szczecin (ca. 400,000 of inhabitants, Poland. Nuclear pedigrees in both groups were compared for frequency of occurrence of clinical features, that have been shown to be associated with HNPCC. Part II 52 consecutive CRC cases from Szczecin, matching the criteria recognized in part I as appropriate for diagnosis of cases "suspected of HNPCC" were studied for the occurrence of germline hMSH2/hMLH1 constitutional mutations using "exon by exon" sequencing. Results The combination of features - i.e. the occurrence of an HNPCC associated cancer (CRC or cancer of the endometrium, small bowel or urinary tract in a 1st degree relative of a CRC patient; at least one of the patients being diagnosed under age of 50 - appeared to be strongly associated to HNPCC with an OR - 161. Constitutional

  6. International Suspect Screening: NORMAN Suspect Exchange meets the US EPA CompTox Chemistry Dashboard (ICCE 2017 Oslo)

    Science.gov (United States)

    Members of the European NORMAN Network of Environmental Laboratories (www.norman-network.com) have many substance lists, including targets, suspects, surfactants, perfluorinated substances and regulated, partially confidential data sets of complex mixtures. The NORMAN Suspect Lis...

  7. Epidemic spreading in a hierarchical social network.

    Science.gov (United States)

    Grabowski, A; Kosiński, R A

    2004-09-01

    A model of epidemic spreading in a population with a hierarchical structure of interpersonal interactions is described and investigated numerically. The structure of interpersonal connections is based on a scale-free network. Spatial localization of individuals belonging to different social groups, and the mobility of a contemporary community, as well as the effectiveness of different interpersonal interactions, are taken into account. Typical relations characterizing the spreading process, like a range of epidemic and epidemic curves, are discussed. The influence of preventive vaccinations on the spreading process is investigated. The critical value of preventively vaccinated individuals that is sufficient for the suppression of an epidemic is calculated. Our results are compared with solutions of the master equation for the spreading process and good agreement of the character of this process is found.

  8. Modeling Epidemics Spreading on Social Contact Networks.

    Science.gov (United States)

    Zhang, Zhaoyang; Wang, Honggang; Wang, Chonggang; Fang, Hua

    2015-09-01

    Social contact networks and the way people interact with each other are the key factors that impact on epidemics spreading. However, it is challenging to model the behavior of epidemics based on social contact networks due to their high dynamics. Traditional models such as susceptible-infected-recovered (SIR) model ignore the crowding or protection effect and thus has some unrealistic assumption. In this paper, we consider the crowding or protection effect and develop a novel model called improved SIR model. Then, we use both deterministic and stochastic models to characterize the dynamics of epidemics on social contact networks. The results from both simulations and real data set conclude that the epidemics are more likely to outbreak on social contact networks with higher average degree. We also present some potential immunization strategies, such as random set immunization, dominating set immunization, and high degree set immunization to further prove the conclusion.

  9. The prediction of epidemics through mathematical modeling.

    Science.gov (United States)

    Schaus, Catherine

    2014-01-01

    Mathematical models may be resorted to in an endeavor to predict the development of epidemics. The SIR model is one of the applications. Still too approximate, the use of statistics awaits more data in order to come closer to reality.

  10. The hidden epidemic: confronting sexually transmitted diseases

    National Research Council Canada - National Science Library

    Eng, Thomas R; Butler, William T

    .... In addition, STDs increase the risk of HIV transmission. The Hidden Epidemic examines the scope of sexually transmitted infections in the United States and provides a critical assessment of the nation's response to this public health crisis...

  11. Epidemic spreading on weighted complex networks

    International Nuclear Information System (INIS)

    Sun, Ye; Liu, Chuang; Zhang, Chu-Xu; Zhang, Zi-Ke

    2014-01-01

    Nowadays, the emergence of online services provides various multi-relation information to support the comprehensive understanding of the epidemic spreading process. In this Letter, we consider the edge weights to represent such multi-role relations. In addition, we perform detailed analysis of two representative metrics, outbreak threshold and epidemic prevalence, on SIS and SIR models. Both theoretical and simulation results find good agreements with each other. Furthermore, experiments show that, on fully mixed networks, the weight distribution on edges would not affect the epidemic results once the average weight of whole network is fixed. This work may shed some light on the in-depth understanding of epidemic spreading on multi-relation and weighted networks.

  12. Epidemic spreading on weighted complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ye [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Liu, Chuang, E-mail: liuchuang@hznu.edu.cn [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Chu-Xu [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Zi-Ke, E-mail: zhangzike@gmail.com [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China)

    2014-01-31

    Nowadays, the emergence of online services provides various multi-relation information to support the comprehensive understanding of the epidemic spreading process. In this Letter, we consider the edge weights to represent such multi-role relations. In addition, we perform detailed analysis of two representative metrics, outbreak threshold and epidemic prevalence, on SIS and SIR models. Both theoretical and simulation results find good agreements with each other. Furthermore, experiments show that, on fully mixed networks, the weight distribution on edges would not affect the epidemic results once the average weight of whole network is fixed. This work may shed some light on the in-depth understanding of epidemic spreading on multi-relation and weighted networks.

  13. Epidemics and rumours in complex networks

    CERN Document Server

    Draief, Moez

    2009-01-01

    Information propagation through peer-to-peer systems, online social systems, wireless mobile ad hoc networks and other modern structures can be modelled as an epidemic on a network of contacts. Understanding how epidemic processes interact with network topology allows us to predict ultimate course, understand phase transitions and develop strategies to control and optimise dissemination. This book is a concise introduction for applied mathematicians and computer scientists to basic models, analytical tools and mathematical and algorithmic results. Mathematical tools introduced include coupling

  14. Phylodynamic analysis of HIV sub-epidemics in Mochudi, Botswana

    Directory of Open Access Journals (Sweden)

    Vlad Novitsky

    2015-12-01

    Real-time HIV genotyping and breaking down local HIV epidemics into phylogenetically distinct sub-epidemics may help to reveal the structure and dynamics of HIV transmission networks in communities, and aid in the design of targeted interventions for members of the acute sub-epidemics that likely fuel local HIV/AIDS epidemics.

  15. Immediate Effect of 3% Diquafosol Ophthalmic Solution on Tear MUC5AC Concentration and Corneal Wetting Ability in Normal and Experimental Keratoconjunctivitis Sicca Rat Models.

    Science.gov (United States)

    Choi, Kwang-Eon; Song, Jong-Suk; Kang, Boram; Eom, Youngsub; Kim, Hyo-Myung

    2017-05-01

    To evaluate the immediate effect of 3% diquafosol ophthalmic solution on tear MUC5AC concentration, periodic acid-Schiff (PAS)-positive goblet cells, and tear film stability in normal and keratoconjunctivitis sicca (KCS) rat models. Rats were divided into normal and KCS groups. 3% of diquafosol solution was instilled into the right eye and normal saline into the left eye in both groups. To determine the peak time of tear MUC5AC concentration, tears were collected after 3% diquafosol instillation every 5 min up to 20 min. The tear film stability and the numbers of PAS-positive goblet cells were compared in both models. After diquafosol instillation, tear MUC5AC concentration increased steadily for 15 min, at which point the MUC5AC concentration reached its peak. In both normal and KCS groups, the MUC5AC concentration at 15 min was higher after instillation of 3% diquafosol solution (17.77 ± 2.09 ng/ml in the normal group, 9.65 ± 3.51 ng/ml in the KCS group) than that after saline instillation (13.74 ± 2.87 ng/ml in the normal group, 8.19 ± 3.99 ng/ml in the KCS group) (p = 0.018 for both). The corneal wetting ability was significantly longer after instillation of 3% diquafosol solution compared with that after instillation of normal saline in the normal group (p = 0.018). The percentage of PAS-positive goblet cells after the instillation of 3% diquafosol solution was significantly lower than that after instillation of normal saline in both models (p = 0.018 for both). Diquafosol ophthalmic solution was effective in stimulating mucin secretion in both normal and KCS rat models, and the peak time of tear MUC5AC concentration was 15 min after diquafosol instillation. The increased tear MUC5AC concentration was accompanied by improved tear film stability and a decreased percentage of PAS-positive goblet cells.

  16. Believable Suspect Agents: Response and Interpersonal Style Selection for an Artificial Suspect

    NARCIS (Netherlands)

    Bruijnes, Merijn

    2016-01-01

    The social skills necessary to properly and successfully conduct a police interrogation can and need to be trained. In the thesis I will describe the steps I took towards a virtual character that can play the role of a suspect in a police interrogation training. Students of the police academy will

  17. Concurrency can drive an HIV epidemic by moving R0 across the epidemic threshold

    NARCIS (Netherlands)

    Leung, Ka Yin; Kretzschmar, Mirjam

    2015-01-01

    OBJECTIVE: The objective of this study is to investigate whether concurrency can drive an HIV epidemic by moving R0 across the epidemic threshold. DESIGN AND METHODS: We use a mathematical framework for a dynamic partnership network and the spread of a one-stage infection to study how concurrency is

  18. Exome Sequencing in Suspected Monogenic Dyslipidemias

    Science.gov (United States)

    Stitziel, Nathan O.; Peloso, Gina M.; Abifadel, Marianne; Cefalu, Angelo B.; Fouchier, Sigrid; Motazacker, M. Mahdi; Tada, Hayato; Larach, Daniel B.; Awan, Zuhier; Haller, Jorge F.; Pullinger, Clive R.; Varret, Mathilde; Rabès, Jean-Pierre; Noto, Davide; Tarugi, Patrizia; Kawashiri, Masa-aki; Nohara, Atsushi; Yamagishi, Masakazu; Risman, Marjorie; Deo, Rahul; Ruel, Isabelle; Shendure, Jay; Nickerson, Deborah A.; Wilson, James G.; Rich, Stephen S.; Gupta, Namrata; Farlow, Deborah N.; Neale, Benjamin M.; Daly, Mark J.; Kane, John P.; Freeman, Mason W.; Genest, Jacques; Rader, Daniel J.; Mabuchi, Hiroshi; Kastelein, John J.P.; Hovingh, G. Kees; Averna, Maurizio R.; Gabriel, Stacey; Boileau, Catherine; Kathiresan, Sekar

    2015-01-01

    Background Exome sequencing is a promising tool for gene mapping in Mendelian disorders. We utilized this technique in an attempt to identify novel genes underlying monogenic dyslipidemias. Methods and Results We performed exome sequencing on 213 selected family members from 41 kindreds with suspected Mendelian inheritance of extreme levels of low-density lipoprotein (LDL) cholesterol (after candidate gene sequencing excluded known genetic causes for high LDL cholesterol families) or high-density lipoprotein (HDL) cholesterol. We used standard analytic approaches to identify candidate variants and also assigned a polygenic score to each individual in order to account for their burden of common genetic variants known to influence lipid levels. In nine families, we identified likely pathogenic variants in known lipid genes (ABCA1, APOB, APOE, LDLR, LIPA, and PCSK9); however, we were unable to identify obvious genetic etiologies in the remaining 32 families despite follow-up analyses. We identified three factors that limited novel gene discovery: (1) imperfect sequencing coverage across the exome hid potentially causal variants; (2) large numbers of shared rare alleles within families obfuscated causal variant identification; and (3) individuals from 15% of families carried a significant burden of common lipid-related alleles, suggesting complex inheritance can masquerade as monogenic disease. Conclusions We identified the genetic basis of disease in nine of 41 families; however, none of these represented novel gene discoveries. Our results highlight the promise and limitations of exome sequencing as a discovery technique in suspected monogenic dyslipidemias. Considering the confounders identified may inform the design of future exome sequencing studies. PMID:25632026

  19. HIV epidemics in Shenzhen and Chongqing, China.

    Directory of Open Access Journals (Sweden)

    Shu Yang

    Full Text Available Men who have sex with men (MSM and heterosexuals are the populations with the fastest growing HIV infection rates in China. We characterize the epidemic growth and age patterns between these two routes from 2004 to 2015 in Chongqing and Shenzhen, China.Data were downloaded from the National HIV/ AIDS Comprehensive Response Information Management System. For the new HIV diagnoses of heterosexuals and MSM in both cities, we estimated the growth rates by fitting different sub-exponential models. Heat maps are used to show their age patterns. We used histograms to compare these patterns by birth cohort.The MSM epidemics grew significantly in both cities. Chongqing experienced quadratic growth in HIV reported cases with an estimated growth rate of 0.086 per week and a "deceleration rate" of 0.673. HIV reported cases of MSM in Shenzhen grew even more drastically with a growth rate of 0.033 per week and "deceleration rate" of 0.794. The new infections are mainly affecting the ages of 18 to 30 in Chongqing and ages of 20 to 35 in Shenzhen. They peaked in early 1990's and mid-1990's birth cohorts in Chongqing and Shenzhen respectively. The HIV epidemic among heterosexuals grew rapidly in both cities. The growth rates were estimated as 0.02 and 0.028 in Chongqing and Shenzhen respectively whereas the "deceleration rates" were 0.878 and 0.790 in these two places. It affected mostly aged 18 to 75 in males and 18 to 65 in females in Chongqing and aged 18 to 45 in males and 18 to 50 in females in Shenzhen in 2015. In Chongqing, the heterosexual female epidemics display two peaks in HIV diagnoses in the birth cohorts of early 1950's and early 1980's, with heterosexual male epidemics peaked in early 1940's and early 1960's. The heterosexual male and female epidemics display higher rates in the birth cohort 1940-1960, than the birth cohort 1960-1990. It peaked in birth cohorts of 1950's and 1980's in Shenzhen.We revealed striking differences in epidemic growth

  20. Ten Putative Contributors to the Obesity Epidemic

    Science.gov (United States)

    McAllister, Emily J.; Dhurandhar, Nikhil V.; Keith, Scott W.; Aronne, Louis J.; Barger, Jamie; Baskin, Monica; Benca, Ruth M.; Biggio, Joseph; Boggiano, Mary M.; Eisenmann, Joe C.; Elobeid, Mai; Fontaine, Kevin R.; Gluckman, Peter; Hanlon, Erin C.; Katzmarzyk, Peter; Pietrobelli, Angelo; Redden, David T.; Ruden, Douglas M.; Wang, Chenxi; Waterland, Robert A.; Wright, Suzanne M.; Allison, David B.

    2010-01-01

    The obesity epidemic is a global issue and shows no signs of abating, while the cause of this epidemic remains unclear. Marketing practices of energy-dense foods and institutionally-driven declines in physical activity are the alleged perpetrators for the epidemic, despite a lack of solid evidence to demonstrate their causal role. While both may contribute to obesity, we call attention to their unquestioned dominance in program funding and public efforts to reduce obesity, and propose several alternative putative contributors that would benefit from equal consideration and attention. Evidence for microorganisms, epigenetics, increasing maternal age, greater fecundity among people with higher adiposity, assortative mating, sleep debt, endocrine disruptors, pharmaceutical iatrogenesis, reduction in variability of ambient temperatures, and intrauterine and intergenerational effects, as contributing factors to the obesity epidemic are reviewed herein. While the evidence is strong for some contributors such as pharmaceutical-induced weight gain, it is still emerging for other reviewed factors. Considering the role of such putative etiological factors of obesity may lead to comprehensive, cause specific, and effective strategies for prevention and treatment of this global epidemic. PMID:19960394

  1. Health seeking behaviour among suspected cases of cholera in Cameroonian health districts in Lake Chad basin.

    Science.gov (United States)

    Yakum, Martin Ndinakie; Ateudjieu, Jerome; Guenou, Etienne; Walter, Ebile Akoh; Ram, Malathi; Debes, Amanda K; Njimbia, Anthony Chebe; Nafack, Sonia Sonkeng; Sack, David A

    2017-08-30

    Cholera outbreaks are recurrent in Cameroon and despite the efforts put together during epidemics, they are always associated with a high case fatality. Inadequate demand for health care is one of the major factors that might be responsible for the high case fatality. This study was conducted to describe the health seeking behaviour of suspected cases of cholera in four health districts of the Far North Cameroon. We conducted a health facility based descriptive study involving suspected cases of cholera received in health facilities. Data was collected from August 2013 to October 2015 with the help of a questionnaire and analysis done by running frequency and calculating confidence interval at 95% with Epi Info version 3.5.4. A total of 1849 cases were enrolled, with 997 (53.9%) being males. 534 (28.9%) were children under the age of 5 and 942 (50.9%) were above the age of 14. About 373 (20%) of diarrhoeal patients arrived in the health facility more than 2 days following the onset of diarrhoea, with 916 (50%) of them being seriously dehydrated. Also, about 624 (34%) of these patients had sought treatment elsewhere before coming to the health facility where they were enrolled, and about 86% of them did not received ORS. Taking 2 or more days after diarrhoea onset or taking more than 1 h to travel from home to health facility was associated with severe dehydration in patients. The delay between the onset of diarrhoea and seeking treatment from a health provider determines the seriousness of suspected cases of cholera in the Far North Cameroon. While conducting an anthropological study to understand reasons why a health provider is not the first option during diarrhoeal episodes, we recommend that a system of community case detection and reference to health facilities should be put in place during cholera outbreaks to minimize its case fatality rate.

  2. Can epidemics be non-communicable?

    DEFF Research Database (Denmark)

    Seeberg, Jens; Meinert, Lotte

    2015-01-01

    This article argues that the concept of communicability that is central to the distinction between communicable diseases (CDs) and noncommunicable diseases (NCDs) is poorly conceptualized. The epidemic spread of NCDs such as diabetes, depression, and eating disorders demonstrates...... that they are communicable, even if they are not infectious. We need to more critically explore how they might be communicable in specific environments. All diseases with epidemic potential, we argue, should be assumed to be commun icable in a broader sense, and that the underlying medical distinction between infectious...... and noninfectious diseases confuses our understanding of NCD epidemics when these categories are treated as synonymous with ‘communicable’ and ‘noncommunicable’ diseases, respectively. The dominant role accorded to the concept of ‘lifestyle’, with its focus on individual responsibility, is part of the problem...

  3. Worm epidemics in wireless ad hoc networks

    Energy Technology Data Exchange (ETDEWEB)

    Nekovee, Maziar [BT Research, Polaris 134, Adastral Park, Martlesham, Suffolk IP5 3RE (United Kingdom); Centre for Computational Science, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom)

    2007-06-15

    A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.

  4. Urgent epidemic control mechanism for aviation networks

    KAUST Repository

    Peng, Chengbin; Wang, Shengbin; Shi, Meixia; Jin, Xiaogang

    2011-01-01

    In the current century, the highly developed transportation system can not only boost the economy, but also greatly accelerate the spreading of epidemics. While some epidemic diseases may infect quite a number of people ahead of our awareness, the health care resources such as vaccines and the medical staff are usually locally or even globally insufficient. In this research, with the network of major aviation routes as an example, we present a method to determine the optimal locations to allocate the medical service in order to minimize the impact of the infectious disease with limited resources. Specifically, we demonstrate that when the medical resources are insufficient, we should concentrate our efforts on the travelers with the objective of effectively controlling the spreading rate of the epidemic diseases. © 2011 Springer-Verlag Berlin Heidelberg.

  5. Vaccination intervention on epidemic dynamics in networks

    Science.gov (United States)

    Peng, Xiao-Long; Xu, Xin-Jian; Fu, Xinchu; Zhou, Tao

    2013-02-01

    Vaccination is an important measure available for preventing or reducing the spread of infectious diseases. In this paper, an epidemic model including susceptible, infected, and imperfectly vaccinated compartments is studied on Watts-Strogatz small-world, Barabási-Albert scale-free, and random scale-free networks. The epidemic threshold and prevalence are analyzed. For small-world networks, the effective vaccination intervention is suggested and its influence on the threshold and prevalence is analyzed. For scale-free networks, the threshold is found to be strongly dependent both on the effective vaccination rate and on the connectivity distribution. Moreover, so long as vaccination is effective, it can linearly decrease the epidemic prevalence in small-world networks, whereas for scale-free networks it acts exponentially. These results can help in adopting pragmatic treatment upon diseases in structured populations.

  6. Worm epidemics in wireless ad hoc networks

    Science.gov (United States)

    Nekovee, Maziar

    2007-06-01

    A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.

  7. GENERAL: Epidemic spreading on networks with vaccination

    Science.gov (United States)

    Shi, Hong-Jing; Duan, Zhi-Sheng; Chen, Guan-Rong; Li, Rong

    2009-08-01

    In this paper, a new susceptible-infected-susceptible (SIS) model on complex networks with imperfect vaccination is proposed. Two types of epidemic spreading patterns (the recovered individuals have or have not immunity) on scale-free networks are discussed. Both theoretical and numerical analyses are presented. The epidemic thresholds related to the vaccination rate, the vaccination-invalid rate and the vaccination success rate on scale-free networks are demonstrated, showing different results from the reported observations. This reveals that whether or not the epidemic can spread over a network under vaccination control is determined not only by the network structure but also by the medicine's effective duration. Moreover, for a given infective rate, the proportion of individuals to vaccinate can be calculated theoretically for the case that the recovered nodes have immunity. Finally, simulated results are presented to show how to control the disease prevalence.

  8. Different Epidemic Models on Complex Networks

    International Nuclear Information System (INIS)

    Zhang Haifeng; Small, Michael; Fu Xinchu

    2009-01-01

    Models for diseases spreading are not just limited to SIS or SIR. For instance, for the spreading of AIDS/HIV, the susceptible individuals can be classified into different cases according to their immunity, and similarly, the infected individuals can be sorted into different classes according to their infectivity. Moreover, some diseases may develop through several stages. Many authors have shown that the individuals' relation can be viewed as a complex network. So in this paper, in order to better explain the dynamical behavior of epidemics, we consider different epidemic models on complex networks, and obtain the epidemic threshold for each case. Finally, we present numerical simulations for each case to verify our results.

  9. Worm epidemics in wireless ad hoc networks

    International Nuclear Information System (INIS)

    Nekovee, Maziar

    2007-01-01

    A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet

  10. The epidemic of Tuberculosis on vaccinated population

    Science.gov (United States)

    Syahrini, Intan; Sriwahyuni; Halfiani, Vera; Meurah Yuni, Syarifah; Iskandar, Taufiq; Rasudin; Ramli, Marwan

    2017-09-01

    Tuberculosis is an infectious disease which has caused a large number of mortality in Indonesia. This disease is caused by Mycrobacterium tuberculosis. Besides affecting lung, this disease also affects other organs such as lymph gland, intestine, kidneys, uterus, bone, and brain. This article discusses the epidemic of tuberculosis through employing the SEIR model. Here, the population is divided into four compartments which are susceptible, exposed, infected and recovered. The susceptible population is further grouped into two which are vaccinated group and unvaccinated group. The behavior of the epidemic is investigated through analysing the equilibrium of the model. The result shows that administering vaccine to the susceptible population contributes to the reduction of the tuberculosis epidemic rate.

  11. Lineup composition, suspect position, and the sequential lineup advantage.

    Science.gov (United States)

    Carlson, Curt A; Gronlund, Scott D; Clark, Steven E

    2008-06-01

    N. M. Steblay, J. Dysart, S. Fulero, and R. C. L. Lindsay (2001) argued that sequential lineups reduce the likelihood of mistaken eyewitness identification. Experiment 1 replicated the design of R. C. L. Lindsay and G. L. Wells (1985), the first study to show the sequential lineup advantage. However, the innocent suspect was chosen at a lower rate in the simultaneous lineup, and no sequential lineup advantage was found. This led the authors to hypothesize that protection from a sequential lineup might emerge only when an innocent suspect stands out from the other lineup members. In Experiment 2, participants viewed a simultaneous or sequential lineup with either the guilty suspect or 1 of 3 innocent suspects. Lineup fairness was varied to influence the degree to which a suspect stood out. A sequential lineup advantage was found only for the unfair lineups. Additional analyses of suspect position in the sequential lineups showed an increase in the diagnosticity of suspect identifications as the suspect was placed later in the sequential lineup. These results suggest that the sequential lineup advantage is dependent on lineup composition and suspect position. (c) 2008 APA, all rights reserved

  12. Ceratoconjuntivite alérgica e complicações no segmento ocular anterior de pacientes Evaluation of anterior ocular segment complications in patients with allergic keratoconjunctivitis

    Directory of Open Access Journals (Sweden)

    Patrícia Bezerra de Menezes Botelho

    2003-01-01

    with secondary anterior segment alterations. Data collected from the charts were: age, gender, kind of allergy, time of disease, time that complication appeared after treatment in our Service, side effects and ocular complications. RESULTS: Complications of anterior segment that caused reduction in visual acuity were: shield ulcers, 5 cases; cataract, 3 cases; corneal opacity, 6 cases; ocular perforation, 2 cases and keratoconus 13 cases. There were 7 surgeries: 2 tectonic penetrating keratoplasty, 4 optic keratoplasty, 4 optic penetrating keratoplasty and one superficial keratectomy. CONCLUSION: Patients with allergic keratoconjunctivitis should be treated in order to prevent ocular complications like keratitis, keratoconus, opacities and cataract.

  13. Gendered Epidemics and Systems of Power in Africa: A Feminist ...

    African Journals Online (AJOL)

    creating an environment that increases women's vulnerability to epidemics. The article ..... to epidemics because rarely, if ever, does a single reason account for their vulnerability. ... life as a young woman. Contraception gave her freedom from.

  14. the south african hiv epidemic, reflected by nine provincial ...

    African Journals Online (AJOL)

    the distribution and trend of the HIV epidemic in each of the ... The exponential model significantly explains the HIV epidemics in the .... such a curve is considered to be made up of three. October 199 ..... Ut: Quantitative Forecasting Methods.

  15. Phylogenetics of the Danish HIV epidemic

    DEFF Research Database (Denmark)

    Audelin, Anne Margrethe; Cowan, Susan A; Obel, Niels

    2013-01-01

    BACKGROUND:: In Denmark 300 new individuals are diagnosed with HIV every year, despite decades of public health campaigns aimed to raise awareness of potential risk behaviour for HIV transmission. It is important to identify the driving forces of the epidemic, to enable more targeted campaigns...

  16. CDC Vital Signs: Today's Heroin Epidemic

    Science.gov (United States)

    ... the MMWR Science Clips Today’s Heroin Epidemic More people at risk, multiple drugs abused Language: English (US) Español Recommend on Facebook Tweet Share Compartir On This Page Overview Problem Infographics What Can Be Done Issue Details Overview Heroin use has increased across the US among men and ...

  17. [A prognostic model of a cholera epidemic].

    Science.gov (United States)

    Boev, B V; Bondarenko, V M; Prokop'eva, N V; San Román, R T; Raygoza-Anaya, M; García de Alba, R

    1994-01-01

    A new model for the prognostication of cholera epidemic on the territory of a large city is proposed. This model reflects the characteristic feature of contacting infection by sensitive individuals due to the preservation of Vibrio cholerae in their water habitat. The mathematical model of the epidemic quantitatively reflects the processes of the spread of infection by kinetic equations describing the interaction of the streams of infected persons, the causative agents and susceptible persons. The functions and parameters of the model are linked with the distribution of individuals according to the duration of the incubation period and infectious process, as well as the period of asymptomatic carrier state. The computer realization of the model by means of IBM PC/AT made it possible to study the cholera epidemic which took place in Mexico in 1833. The verified model of the cholera epidemic was used for the prognostication of the possible spread of this infection in Guadalajara, taking into account changes in the epidemiological situation and the size of the population, as well as improvements in sanitary and hygienic conditions, in the city.

  18. The Prescription Opioid Pain Medication Overdose Epidemic

    Centers for Disease Control (CDC) Podcasts

    2016-04-19

    Overdose related to prescription opioids has become an epidemic. This podcast discusses the risks of this type of drug sometimes used to treat pain, and how to protect yourself. .  Created: 4/19/2016 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 4/19/2016.

  19. Alternative risk financing instruments for swine epidemics

    NARCIS (Netherlands)

    Meuwissen, M.P.M.; Asseldonk, van M.A.P.M.; Huirne, R.B.M.

    2003-01-01

    Swine epidemics can have very large devastating financial consequences. Governments generally bear the direct losses, such as the value of destroyed animals. Consequential losses, such as the losses resulting from empty buildings and movement standstills, are completely borne by the farmers (and

  20. A Weighted Configuration Model and Inhomogeneous Epidemics

    Science.gov (United States)

    Britton, Tom; Deijfen, Maria; Liljeros, Fredrik

    2011-12-01

    A random graph model with prescribed degree distribution and degree dependent edge weights is introduced. Each vertex is independently equipped with a random number of half-edges and each half-edge is assigned an integer valued weight according to a distribution that is allowed to depend on the degree of its vertex. Half-edges with the same weight are then paired randomly to create edges. An expression for the threshold for the appearance of a giant component in the resulting graph is derived using results on multi-type branching processes. The same technique also gives an expression for the basic reproduction number for an epidemic on the graph where the probability that a certain edge is used for transmission is a function of the edge weight (reflecting how closely `connected' the corresponding vertices are). It is demonstrated that, if vertices with large degree tend to have large (small) weights on their edges and if the transmission probability increases with the edge weight, then it is easier (harder) for the epidemic to take off compared to a randomized epidemic with the same degree and weight distribution. A recipe for calculating the probability of a large outbreak in the epidemic and the size of such an outbreak is also given. Finally, the model is fitted to three empirical weighted networks of importance for the spread of contagious diseases and it is shown that R 0 can be substantially over- or underestimated if the correlation between degree and weight is not taken into account.

  1. Epidemic spreading on preferred degree adaptive networks.

    Science.gov (United States)

    Jolad, Shivakumar; Liu, Wenjia; Schmittmann, B; Zia, R K P

    2012-01-01

    We study the standard SIS model of epidemic spreading on networks where individuals have a fluctuating number of connections around a preferred degree κ. Using very simple rules for forming such preferred degree networks, we find some unusual statistical properties not found in familiar Erdös-Rényi or scale free networks. By letting κ depend on the fraction of infected individuals, we model the behavioral changes in response to how the extent of the epidemic is perceived. In our models, the behavioral adaptations can be either 'blind' or 'selective'--depending on whether a node adapts by cutting or adding links to randomly chosen partners or selectively, based on the state of the partner. For a frozen preferred network, we find that the infection threshold follows the heterogeneous mean field result λ(c)/μ = / and the phase diagram matches the predictions of the annealed adjacency matrix (AAM) approach. With 'blind' adaptations, although the epidemic threshold remains unchanged, the infection level is substantially affected, depending on the details of the adaptation. The 'selective' adaptive SIS models are most interesting. Both the threshold and the level of infection changes, controlled not only by how the adaptations are implemented but also how often the nodes cut/add links (compared to the time scales of the epidemic spreading). A simple mean field theory is presented for the selective adaptations which capture the qualitative and some of the quantitative features of the infection phase diagram.

  2. [Notes about other epidemics in Colonial Chile].

    Science.gov (United States)

    Laval, Enrique

    2015-10-01

    In chronicles or in the historiography of the Colony in Chile there are few references about epidemics different to smallpox; like typhus, typhoid fever, dysentery, etc. Almost all, fast spreading in the country and some with high lethality, which led to overflowing the capacity of hospitals in the Chilean colonial period.

  3. Epidemic spreading through direct and indirect interactions.

    Science.gov (United States)

    Ganguly, Niloy; Krueger, Tyll; Mukherjee, Animesh; Saha, Sudipta

    2014-09-01

    In this paper we study the susceptible-infected-susceptible epidemic dynamics, considering a specialized setting where popular places (termed passive entities) are visited by agents (termed active entities). We consider two types of spreading dynamics: direct spreading, where the active entities infect each other while visiting the passive entities, and indirect spreading, where the passive entities act as carriers and the infection is spread via them. We investigate in particular the effect of selection strategy, i.e., the way passive entities are chosen, in the spread of epidemics. We introduce a mathematical framework to study the effect of an arbitrary selection strategy and derive formulas for prevalence, extinction probabilities, and epidemic thresholds for both indirect and direct spreading. We also obtain a very simple relationship between the extinction probability and the prevalence. We pay special attention to preferential selection and derive exact formulas. The analysis reveals that an increase in the diversity in the selection process lowers the epidemic thresholds. Comparing the direct and indirect spreading, we identify regions in the parameter space where the prevalence of the indirect spreading is higher than the direct one.

  4. Cholera Epidemic Control | Zachariah | Malawi Medical Journal

    African Journals Online (AJOL)

    Malawi Medical Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 13, No 1 (2001) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Cholera Epidemic Control. R Zachariah. Full Text: EMAIL FREE ...

  5. Social epidemics in the aftermath of disasters.

    NARCIS (Netherlands)

    IJzermans, C.J.

    2002-01-01

    Issue/problem: After disasters, terrorist attacks and wars social epidemics of medically unexplained physical symptoms/syndromes (ups) are often seen. In modern times people feel more vulnerable and especially under pressure of those incidents, everyday symptoms are interpreted as disease and

  6. Zika virus epidemic: the newest international emergency

    Directory of Open Access Journals (Sweden)

    Ruth Minamisava

    2016-03-01

    production, accurate diagnosis and treatment, training for caring for neurological syndromes and congenital malformations. (iii          Measures for travelers: counseling, disinfestation of aircrafts and airports. (iv          Sharing of information. Some inquiries have been made about the magnitude of this epidemic and its association with microcephaly and neurological disorders(4-5. It is reasonable to consider that there is an underreporting of microcephaly in the records of the Live Births Information System in Brazil. It is also to be expected that, after the national alert, the number of suspected cases would rise. When there is an increase or the implementation of surveillance, this always results in higher sensitivity of detection of suspected/reported cases with an increase in false positives. For these reasons, it is possible to say that part of the increase in reported cases of microcephaly may be attributable to the current intense surveillance. What is inconceivable, however, is that the prevalence of microcephaly in northeastern Brazil is 10 to 20 times higher than in other countries(6. At present, there are hypotheses that the Zika virus may have an etiologic and/or pathophysiological role for these events, which is usually rare. What seems indisputable is the gravity of the situation. Health managers cannot wait for high-level scientific evidence. Care and prudence when assessing is advisable, and the same goes for avoiding premature conclusions. However, given the potential threat, we have a duty to at least protect pregnant women and their fetuses. The current situation poses many challenges that we need to face and it seems logical that Brazil take the lead in beginning the actions. We recognize in our history both the success in the fight against yellow fever early in the last century and also our recent inefficiency in the fight against the Aedes aegypti mosquito to control dengue and chikungunya. It is necessary to create, renew, and

  7. The clinical course of patients with suspected pulmonary embolism

    NARCIS (Netherlands)

    van Beek, E. J.; Kuijer, P. M.; Büller, H. R.; Brandjes, D. P.; Bossuyt, P. M.; ten Cate, J. W.

    1997-01-01

    BACKGROUND: The outcome of patients with suspected pulmonary embolism is known to a limited extent only. OBJECTIVE: To address this limited knowledge in a cohort in whom pulmonary embolism was proved or ruled out. METHODS: Consecutive patients with clinically suspected pulmonary embolism underwent

  8. 48 CFR 403.303 - Reporting suspected antitrust violations.

    Science.gov (United States)

    2010-10-01

    ... Antitrust Violations 403.303 Reporting suspected antitrust violations. Contracting officers shall report the circumstances of suspected violations of antitrust laws to the Office of Inspector General in accordance with... antitrust violations. 403.303 Section 403.303 Federal Acquisition Regulations System DEPARTMENT OF...

  9. 48 CFR 1403.303 - Reporting suspected antitrust violations.

    Science.gov (United States)

    2010-10-01

    ... Antitrust Violations 1403.303 Reporting suspected antitrust violations. (a) Reports on suspected violations of antitrust laws as required by FAR 3.303 shall be prepared by the CO, reviewed by the SOL, and... antitrust violations. 1403.303 Section 1403.303 Federal Acquisition Regulations System DEPARTMENT OF THE...

  10. Detection of Rabies antigen in brains of suspected Rabid dogs ...

    African Journals Online (AJOL)

    Objective: To detect the presence of rabies antigen in brains of suspected rabid dogs. Materials and Methods: Ninety six (96) brain specimens from suspected rabid dogs were examined for the presence of rabies antigen using Seller's staining technique and enzyme immunoassay. Results: The two techniques were both ...

  11. Selecting foils for identification lineups: matching suspects or descriptions?

    Science.gov (United States)

    Tunnicliff, J L; Clark, S E

    2000-04-01

    Two experiments directly compare two methods of selecting foils for identification lineups. The suspect-matched method selects foils based on their match to the suspect, whereas the description-matched method selects foils based on their match to the witness's description of the perpetrator. Theoretical analyses and previous results predict an advantage for description-matched lineups both in terms of correctly identifying the perpetrator and minimizing false identification of innocent suspects. The advantage for description-matched lineups should be particularly pronounced if the foils selected in suspect-matched lineups are too similar to the suspect. In Experiment 1, the lineups were created by trained police officers, and in Experiment 2, the lineups were constructed by undergraduate college students. The results of both experiments showed higher suspect-to-foil similarity for suspect-matched lineups than for description-matched lineups. However, neither experiment showed a difference in correct or false identification rates. Both experiments did, however, show that there may be an advantage for suspect-matched lineups in terms of no-pick and rejection responses. From these results, the endorsement of one method over the other seems premature.

  12. Arthroscintigraphy in suspected rotator cuff rupture

    International Nuclear Information System (INIS)

    Gratz, S.; Behr, T.; Becker, W.; Koester, G.; Vosshenrich, R.; Grabbe, E.

    1998-01-01

    Aim: In order to evaluate the diagnostic efficiency of arthroscintigraphy in suspected rotator cuff ruptures this new imaging procedure was performed 20 times in 17 patients with clinical signs of a rotator cuff lesion. The scintigraphic results were compared with sonography (n=20), contrast arthrography (n=20) and arthroscopy (n=10) of the shoulder joint. Methods: After performing a standard bone scintigraphy with intravenous application of 300 MBq 99m-Tc-methylene diphosphonate (MDP) for landmarking of the shoulder region arthroscintigraphy was performed after an intraarticular injection of 99m-Tc microcolloid (ALBU-RES 400 μCi/5 ml). The application was performed either in direct combination with contrast arthrography (n=10) or ultrasound conducted mixed with a local anesthetic (n=10). Findings at arthroscopical surgery (n=10) were used as the gold standard. Results: In case of complete rotator cuff rupture (n=5), arthroscintigraphy and radiographic arthrography were identical in 5/5. In one patient with advanced degenerative alterations of the shoulder joint radiographic arthrography incorrectly showed a complete rupture which was not seen by arthroscintigraphy and endoscopy. In 3 patients with incomplete rupture, 2/3 results were consistant. A difference was seen in one patient with a rotator cuff, that has been already revised in the past and that suffered of capsulitis and calcification. Conclusion: Arthroscinitgraphy is a sensitive technique for detection of rotator cuff ruptures. Because of the lower viscosity of the active compound, small ruptures can be easily detected, offering additional value over radiographic arthrography and ultrasound, especially for evaluation of incomplete cuff ruptures. (orig.) [de

  13. Suspected synthetic cannabinoid toxicosis in a dog.

    Science.gov (United States)

    Williams, Keysa; Wells, Raegan J; McLean, Mary Kay

    2015-01-01

    To describe the effects of suspected synthetic cannabinoid (SC) toxicosis and the response to intravenous lipid emulsion (ILE) therapy in a dog. A 2-year-8-month-old male Boxer dog was evaluated at an emergency hospital for progressive ataxia and inappropriate mentation. The initial physical examination identified marked hypothermia (32.7°C [90.9°F]), intermittent sinus bradycardia (60/min), stuporous mentation with intermittent aggression, and severe ataxia. Neurologic status deteriorated to comatose mentation within 2 hours of presentation. The initial diagnostic evaluation (eg, CBC, serum biochemistry profile, venous blood gas, and electrolyte determination) revealed a respiratory acidosis and thrombocytopenia. The owner reported that the dog was exposed to an SC containing Damiana leaf, Marshmallow leaf, and Athaea leaves. Initial treatment included IV fluids and supplemental oxygen. Mechanical ventilation was provided due to hypoventilation and periods of apnea. Intravenous lipid emulsion therapy was administered as a bolus (1.5 mL/kg) and continued as a continuous rate infusion (0.5 mL/kg/h) for a total of 6 hours. The dog became rousable and was weaned from mechanical ventilation approximately 15 hours following presentation. The dog was eating and walking with no ataxia, had a normal mentation at approximately 33 hours following presentation, and was discharged home at that time. Communication with the owners 5 days following discharge revealed that the dog was apparently normal. Based on this case and other reports in the literature regarding human exposures, SC ingestion may result in more severe clinical signs than marijuana ingestion in dogs. Significant clinical intervention may be necessary. Intravenous lipid emulsion treatment may be beneficial due to the lipophilicity of SC. © Veterinary Emergency and Critical Care Society 2015.

  14. Economic cost and burden of dengue during epidemics and non-epidemic years in Taiwan

    Directory of Open Access Journals (Sweden)

    Dih-Ling Luh

    2018-03-01

    Full Text Available Background: Determining the disease and economic burden of dengue is critical for the allocation of public health resources. Several studies have used disability-adjusted life-years (DALYs to estimate the disease burden of dengue in different regions. However, there are no published studies discussing the estimates of dengue-related economic and disease burden specifically in Taiwan. Objectives: We assessed the economic cost and disease burden of dengue infections in Taiwan for the period 1998–2014, and compared these during epidemic and non-epidemic years. Methods: We estimated the annual DALYs per million population using the disability weights for dengue fever (DF, dengue hemorrhagic fever (DHF, dengue shock syndrome (DSS, and death cases. Economic costs were estimated and divided into direct (medical costs and indirect costs (lost work days and caregiver fees. Results: For the period 1998–2014, a mean of 115.3 (range: 6.3–934.3 DALYs per million population annually were lost to dengue. In epidemic years, direct costs associated with dengue resulted mostly from hospitalization (86.09%, emergency (7.77%, outpatient (6.10%, and drug costs (0.03%. For indirect costs, lost productivity due to death (70.76% was the dominant contributor. Overall, the costs were 12.3 times higher in epidemic years than in non-epidemic years (Wilcoxon rank sum test, p < 0.05. Conclusions: This study is the first to evaluate the economic costs and disease burden of dengue infections for this period in Taiwan, and reveals significant differences in economic impact between epidemic and non-epidemic years. Keywords: Economic cost of disease, Disease burden, Disability-adjusted life years (DALYs, Dengue, Epidemic

  15. Seasonal variation among tuberculosis suspects in four countries

    DEFF Research Database (Denmark)

    Mabaera, Biggie; Naranbat, Nymadawa; Katamba, Achilles

    2009-01-01

    The objective of the study was to analyze monthly trends across a calendar year in tuberculosis suspects and sputum smear-positive cases based on nationally representative samples of tuberculosis laboratory registers from Moldova, Mongolia, Uganda and Zimbabwe. Out of the 47 140 suspects registered...... in the tuberculosis laboratory registers, 13.4% (6312) were cases. The proportion varied from country to country, Moldova having the lowest (9%) and Uganda the highest (21%). From the monthly proportion of suspects and cases among total suspects and cases, seasonal variations were most marked in Mongolia which, among...... attendance to diagnostic laboratory services, evidenced by the contrasting findings of Mongolia (extreme continental northern climate) compared to Uganda (equatorial climate). A combination of external and possibly endogenous factors seems to determine whether tuberculosis suspects and cases present...

  16. Transferring the Malaria Epidemic Prediction Model to Users in East ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Transferring the Malaria Epidemic Prediction Model to Users in East Africa. In the highlands of East Africa, epidemic malaria is an emerging climate-related hazard that urgently needs addressing. Malaria incidence increased by 337% during the 1987 epidemic in Rwanda. In Tanzania, Uganda and Kenya, malaria incidence ...

  17. Outbreak or Epidemic? How Obama's Language Choice Transformed the Ebola Outbreak Into an Epidemic.

    Science.gov (United States)

    Gesser-Edelsburg, Anat; Shir-Raz, Yaffa; Bar-Lev, Oshrat Sassoni; James, James J; Green, Manfred S

    2016-08-01

    Our aim was to examine in what terms leading newspapers' online sites described the current Ebola crisis. We employed a quantitative content analysis of terms attributed to Ebola. We found and analyzed 582 articles published between March 23 and September 30, 2014, on the online websites of 3 newspapers: The New York Times, Daily Mail, and Ynet. Our theoretical framework drew from the fields of health communication and emerging infectious disease communication, including such concepts as framing media literacy, risk signatures, and mental models. We found that outbreak and epidemic were used interchangeably in the articles. From September 16, 2014, onward, epidemic predominated, corresponding to when President Barack Obama explicitly referred to Ebola as an epidemic. Prior to Obama's speech, 86.8% of the articles (323) used the term outbreak and only 8.6% (32) used the term epidemic. Subsequently, both terms were used almost the same amount: 53.8% of the articles (113) used the term outbreak and 53.3% (112) used the term epidemic. Effective communication is crucial during public health emergencies such as Ebola, because language framing affects the decision-making process of social judgments and actions. The choice of one term (outbreak) over another (epidemic) can create different conceptualizations of the disease, thereby influencing the risk signature. (Disaster Med Public Health Preparedness. 2016;10:669-673).

  18. Integrated travel network model for studying epidemics: Interplay between journeys and epidemic

    Science.gov (United States)

    Ruan, Zhongyuan; Wang, Chaoqing; Ming Hui, Pak; Liu, Zonghua

    2015-06-01

    The ease of travelling between cities has contributed much to globalization. Yet, it poses a threat on epidemic outbreaks. It is of great importance for network science and health control to understand the impact of frequent journeys on epidemics. We stress that a new framework of modelling that takes a traveller’s viewpoint is needed. Such integrated travel network (ITN) model should incorporate the diversity among links as dictated by the distances between cities and different speeds of different modes of transportation, diversity among nodes as dictated by the population and the ease of travelling due to infrastructures and economic development of a city, and round-trip journeys to targeted destinations via the paths of shortest travel times typical of human journeys. An example is constructed for 116 cities in China with populations over one million that are connected by high-speed train services and highways. Epidemic spread on the constructed network is studied. It is revealed both numerically and theoretically that the traveling speed and frequency are important factors of epidemic spreading. Depending on the infection rate, increasing the traveling speed would result in either an enhanced or suppressed epidemic, while increasing the traveling frequency enhances the epidemic spreading.

  19. Parameter Scaling for Epidemic Size in a Spatial Epidemic Model with Mobile Individuals.

    Directory of Open Access Journals (Sweden)

    Chiyori T Urabe

    Full Text Available In recent years, serious infectious diseases tend to transcend national borders and widely spread in a global scale. The incidence and prevalence of epidemics are highly influenced not only by pathogen-dependent disease characteristics such as the force of infection, the latent period, and the infectious period, but also by human mobility and contact patterns. However, the effect of heterogeneous mobility of individuals on epidemic outcomes is not fully understood. Here, we aim to elucidate how spatial mobility of individuals contributes to the final epidemic size in a spatial susceptible-exposed-infectious-recovered (SEIR model with mobile individuals in a square lattice. After illustrating the interplay between the mobility parameters and the other parameters on the spatial epidemic spreading, we propose an index as a function of system parameters, which largely governs the final epidemic size. The main contribution of this study is to show that the proposed index is useful for estimating how parameter scaling affects the final epidemic size. To demonstrate the effectiveness of the proposed index, we show that there is a positive correlation between the proposed index computed with the real data of human airline travels and the actual number of positive incident cases of influenza B in the entire world, implying that the growing incidence of influenza B is attributed to increased human mobility.

  20. Epidemic dynamics and endemic states in complex networks

    Science.gov (United States)

    Pastor-Satorras, Romualdo; Vespignani, Alessandro

    2001-06-01

    We study by analytical methods and large scale simulations a dynamical model for the spreading of epidemics in complex networks. In networks with exponentially bounded connectivity we recover the usual epidemic behavior with a threshold defining a critical point below that the infection prevalence is null. On the contrary, on a wide range of scale-free networks we observe the absence of an epidemic threshold and its associated critical behavior. This implies that scale-free networks are prone to the spreading and the persistence of infections whatever spreading rate the epidemic agents might possess. These results can help understanding computer virus epidemics and other spreading phenomena on communication and social networks.

  1. Epidemic dynamics and endemic states in complex networks

    International Nuclear Information System (INIS)

    Pastor-Satorras, Romualdo; Vespignani, Alessandro

    2001-01-01

    We study by analytical methods and large scale simulations a dynamical model for the spreading of epidemics in complex networks. In networks with exponentially bounded connectivity we recover the usual epidemic behavior with a threshold defining a critical point below that the infection prevalence is null. On the contrary, on a wide range of scale-free networks we observe the absence of an epidemic threshold and its associated critical behavior. This implies that scale-free networks are prone to the spreading and the persistence of infections whatever spreading rate the epidemic agents might possess. These results can help understanding computer virus epidemics and other spreading phenomena on communication and social networks

  2. Toward a generalized theory of epidemic awareness in social networks

    Science.gov (United States)

    Wu, Qingchu; Zhu, Wenfang

    We discuss the dynamics of a susceptible-infected-susceptible (SIS) model with local awareness in networks. Individual awareness to the infectious disease is characterized by a general function of epidemic information in its neighborhood. We build a high-accuracy approximate equation governing the spreading dynamics and derive an approximate epidemic threshold above which the epidemic spreads over the whole network. Our results extend the previous work and show that the epidemic threshold is dependent on the awareness function in terms of one infectious neighbor. Interestingly, when a pow-law awareness function is chosen, the epidemic threshold can emerge in infinite networks.

  3. Epidemic Spreading with Heterogeneous Awareness on Human Networks

    Directory of Open Access Journals (Sweden)

    Yanling Lu

    2017-01-01

    Full Text Available The spontaneous awareness behavioral responses of individuals have a significant impact on epidemic spreading. In this paper, a modified Susceptible-Alert-Infected-Susceptible (SAIS epidemic model with heterogeneous awareness is presented to study epidemic spreading in human networks and the impact of heterogeneous awareness on epidemic dynamics. In this model, when susceptible individuals receive awareness information about the presence of epidemic from their infected neighbor nodes, they will become alert individuals with heterogeneous awareness rate. Theoretical analysis and numerical simulations show that heterogeneous awareness can enhance the epidemic threshold with certain conditions and reduce the scale of virus outbreaks compared with no awareness. What is more, for the same awareness parameter, it also shows that heterogeneous awareness can slow effectively the spreading size and does not delay the arrival time of epidemic spreading peak compared with homogeneous awareness.

  4. Extinction times of epidemic outbreaks in networks.

    Science.gov (United States)

    Holme, Petter

    2013-01-01

    In the Susceptible-Infectious-Recovered (SIR) model of disease spreading, the time to extinction of the epidemics happens at an intermediate value of the per-contact transmission probability. Too contagious infections burn out fast in the population. Infections that are not contagious enough die out before they spread to a large fraction of people. We characterize how the maximal extinction time in SIR simulations on networks depend on the network structure. For example we find that the average distances in isolated components, weighted by the component size, is a good predictor of the maximal time to extinction. Furthermore, the transmission probability giving the longest outbreaks is larger than, but otherwise seemingly independent of, the epidemic threshold.

  5. Epidemic extinction paths in complex networks

    Science.gov (United States)

    Hindes, Jason; Schwartz, Ira B.

    2017-05-01

    We study the extinction of long-lived epidemics on finite complex networks induced by intrinsic noise. Applying analytical techniques to the stochastic susceptible-infected-susceptible model, we predict the distribution of large fluctuations, the most probable or optimal path through a network that leads to a disease-free state from an endemic state, and the average extinction time in general configurations. Our predictions agree with Monte Carlo simulations on several networks, including synthetic weighted and degree-distributed networks with degree correlations, and an empirical high school contact network. In addition, our approach quantifies characteristic scaling patterns for the optimal path and distribution of large fluctuations, both near and away from the epidemic threshold, in networks with heterogeneous eigenvector centrality and degree distributions.

  6. Spread of epidemic disease on networks

    Science.gov (United States)

    Newman, M. E.

    2002-07-01

    The study of social networks, and in particular the spread of disease on networks, has attracted considerable recent attention in the physics community. In this paper, we show that a large class of standard epidemiological models, the so-called susceptible/infective/removed (SIR) models can be solved exactly on a wide variety of networks. In addition to the standard but unrealistic case of fixed infectiveness time and fixed and uncorrelated probability of transmission between all pairs of individuals, we solve cases in which times and probabilities are nonuniform and correlated. We also consider one simple case of an epidemic in a structured population, that of a sexually transmitted disease in a population divided into men and women. We confirm the correctness of our exact solutions with numerical simulations of SIR epidemics on networks.

  7. Ciguatera fish poisoning. A southern California epidemic.

    Science.gov (United States)

    Barton, E D; Tanner, P; Turchen, S G; Tunget, C L; Manoguerra, A; Clark, R F

    1995-01-01

    Ciguatera fish poisoning results from the bioconcentration of a variety of toxins produced by marine dinoflagellates. Signs and symptoms vary widely, but it usually presents as gastrointestinal and neurologic complaints beginning shortly after the ingestion of fish containing the toxins. Symptoms may persist for months and sometimes even years. Although cases have been reported throughout the United States, epidemics are most common along tropical and subtropical coasts and usually involve the ingestion of large carnivorous fish. We review the literature and report the first epidemic of 25 cases of ciguatera fish poisoning presenting to area hospitals in Southern California that were successfully tracked by the Department of Health Services and isolated to fish caught off the coast of Baja California, Mexico. Images Figure 1. PMID:7667980

  8. A break in the obesity epidemic?

    DEFF Research Database (Denmark)

    Visscher, T L S; Heitmann, B L; Rissanen, A

    2015-01-01

    Recent epidemiologic papers are presenting prevalence data suggesting breaks and decreases in obesity rates. However, before concluding that the obesity epidemic is not increasing anymore, the validity of the presented data should be discussed more thoroughly. We had a closer look into the litera......, focusing on trends in waist circumference rather than BMI leads to a less optimistic conclusion: the public health problem of obesity is still increasing.International Journal of Obesity advance online publication, 22 July 2014; doi:10.1038/ijo.2014.98....... into the literature presented in recent reviews to address the major potential biases and distortions, and to develop insights about how to interpret the presented suggestions for a potential break in the obesity epidemic. Decreasing participation rates, the use of reported rather than measured data and small sample...

  9. Eight challenges for network epidemic models

    Directory of Open Access Journals (Sweden)

    Lorenzo Pellis

    2015-03-01

    Full Text Available Networks offer a fertile framework for studying the spread of infection in human and animal populations. However, owing to the inherent high-dimensionality of networks themselves, modelling transmission through networks is mathematically and computationally challenging. Even the simplest network epidemic models present unanswered questions. Attempts to improve the practical usefulness of network models by including realistic features of contact networks and of host–pathogen biology (e.g. waning immunity have made some progress, but robust analytical results remain scarce. A more general theory is needed to understand the impact of network structure on the dynamics and control of infection. Here we identify a set of challenges that provide scope for active research in the field of network epidemic models.

  10. Computational algebraic geometry of epidemic models

    Science.gov (United States)

    Rodríguez Vega, Martín.

    2014-06-01

    Computational Algebraic Geometry is applied to the analysis of various epidemic models for Schistosomiasis and Dengue, both, for the case without control measures and for the case where control measures are applied. The models were analyzed using the mathematical software Maple. Explicitly the analysis is performed using Groebner basis, Hilbert dimension and Hilbert polynomials. These computational tools are included automatically in Maple. Each of these models is represented by a system of ordinary differential equations, and for each model the basic reproductive number (R0) is calculated. The effects of the control measures are observed by the changes in the algebraic structure of R0, the changes in Groebner basis, the changes in Hilbert dimension, and the changes in Hilbert polynomials. It is hoped that the results obtained in this paper become of importance for designing control measures against the epidemic diseases described. For future researches it is proposed the use of algebraic epidemiology to analyze models for airborne and waterborne diseases.

  11. Extinction times of epidemic outbreaks in networks.

    Directory of Open Access Journals (Sweden)

    Petter Holme

    Full Text Available In the Susceptible-Infectious-Recovered (SIR model of disease spreading, the time to extinction of the epidemics happens at an intermediate value of the per-contact transmission probability. Too contagious infections burn out fast in the population. Infections that are not contagious enough die out before they spread to a large fraction of people. We characterize how the maximal extinction time in SIR simulations on networks depend on the network structure. For example we find that the average distances in isolated components, weighted by the component size, is a good predictor of the maximal time to extinction. Furthermore, the transmission probability giving the longest outbreaks is larger than, but otherwise seemingly independent of, the epidemic threshold.

  12. Emergence of epidemics in rapidly varying networks

    International Nuclear Information System (INIS)

    Kohar, Vivek; Sinha, Sudeshna

    2013-01-01

    We describe a simple model mimicking disease spreading on a network with dynamically varying connections, and investigate the dynamical consequences of switching links in the network. Our central observation is that the disease cycles get more synchronized, indicating the onset of epidemics, as the underlying network changes more rapidly. This behavior is found for periodically switched links, as well as links that switch randomly in time. We find that the influence of changing links is more pronounced in networks where the nodes have lower degree, and the disease cycle has a longer infective stage. Further, when the switching of links is periodic we observe finer dynamical features, such as beating patterns in the emergent oscillations and resonant enhancement of synchronization, arising from the interplay between the time-scales of the connectivity changes and that of the epidemic outbreaks

  13. [The depression epidemic does not exist].

    Science.gov (United States)

    van der Feltz-Cornelis, Christina M

    2009-01-01

    There has been much discussion in the media about the question of the existence of a depression epidemic. This leads on to the questions of whether the social and economic approaches are adequate, and what the alternatives are. The concept of the disease 'depression' can be defined using a medical model, or from a patient's or a societal perspective. From a medical perspective, indeed a depression epidemic has ensued from the increased prosperity and the associated decompression of the mortality rate. Society responded with preventative measures and policies aimed at improving functioning in the workplace. However, patients with a major depressive disorder (MDD) who are eligible for treatment are often not motivated to take it up, or are undertreated. Research is necessary in order to explore what patients think about the identification and treatment of depression. The confusion regarding the concept of depression found in the media, needs to be cleared.

  14. New Approaches to the Methamphetamine Epidemic

    OpenAIRE

    Zusman, Mara B.

    2004-01-01

    Methamphetamine abuse has become an epidemic in the United States. As methamphetamine becomes increasingly available, more and more people are trying – and becoming addicted to – this potent drug. But although methamphetamine is made using over-the-counter (OTC) drugs containing pseudoephedrine, shifting OTC drugs containing pseudoephedrine to prescription status is not the solution to the methamphetamine crisis. Rather, society must adopt a comprehensive...

  15. The 1982 epidemic--roller skating injuries.

    Science.gov (United States)

    Bunker, T. D.

    1983-01-01

    A series of 100 roller skating injuries is presented. Roller skating injuries have been occurring at a higher rate than the previously reported skateboarding epidemic of 1977. The severity of injury has been lower, 32% fractures and dislocations occurring whilst roller skating, compared to 60% whilst skateboarding. In particular a striking reduction is seen in ankle fractures. Fifty questionnaires detailing method of injury were analysed. Images p205-a Fig. 1 Fig. 2 PMID:6652406

  16. Impact of the infectious period on epidemics

    Science.gov (United States)

    Wilkinson, Robert R.; Sharkey, Kieran J.

    2018-05-01

    The duration of the infectious period is a crucial determinant of the ability of an infectious disease to spread. We consider an epidemic model that is network based and non-Markovian, containing classic Kermack-McKendrick, pairwise, message passing, and spatial models as special cases. For this model, we prove a monotonic relationship between the variability of the infectious period (with fixed mean) and the probability that the infection will reach any given subset of the population by any given time. For certain families of distributions, this result implies that epidemic severity is decreasing with respect to the variance of the infectious period. The striking importance of this relationship is demonstrated numerically. We then prove, with a fixed basic reproductive ratio (R0), a monotonic relationship between the variability of the posterior transmission probability (which is a function of the infectious period) and the probability that the infection will reach any given subset of the population by any given time. Thus again, even when R0 is fixed, variability of the infectious period tends to dampen the epidemic. Numerical results illustrate this but indicate the relationship is weaker. We then show how our results apply to message passing, pairwise, and Kermack-McKendrick epidemic models, even when they are not exactly consistent with the stochastic dynamics. For Poissonian contact processes, and arbitrarily distributed infectious periods, we demonstrate how systems of delay differential equations and ordinary differential equations can provide upper and lower bounds, respectively, for the probability that any given individual has been infected by any given time.

  17. Dynamics of epidemics outbreaks in heterogeneous populations

    Science.gov (United States)

    Brockmann, Dirk; Morales-Gallardo, Alejandro; Geisel, Theo

    2007-03-01

    The dynamics of epidemic outbreaks have been investigated in recent years within two alternative theoretical paradigms. The key parameter of mean field type of models such as the SIR model is the basic reproduction number R0, the average number of secondary infections caused by one infected individual. Recently, scale free network models have received much attention as they account for the high variability in the number of social contacts involved. These models predict an infinite basic reproduction number in some cases. We investigate the impact of heterogeneities of contact rates in a generic model for epidemic outbreaks. We present a system in which both the time periods of being infectious and the time periods between transmissions are Poissonian processes. The heterogeneities are introduced by means of strongly variable contact rates. In contrast to scale free network models we observe a finite basic reproduction number and, counterintuitively a smaller overall epidemic outbreak as compared to the homogeneous system. Our study thus reveals that heterogeneities in contact rates do not necessarily facilitate the spread to infectious disease but may well attenuate it.

  18. Connecting the obesity and the narcissism epidemics.

    Science.gov (United States)

    Lemaitre, Bruno

    2016-10-01

    Obesity and metabolic syndromes are major threats to health in both developed and developing countries. This opinion article is a holistic attempt to understand the obesity epidemic, by connecting it to the widespread narcissism in society. The narcissism epidemic refers to an increased prevalence of status-striving individualism and a decreased sense of community, observed in Westerns populations and spreading worldwide. Based on social personality and evolutionary psychology approaches, I speculate that this rise of narcissism underlies a steep social hierarchy resulting in increase of social stress. This social stress markedly affects individuals who are sensitive to social hierarchy dominance due to their personality, yet are relegated at a lower social position. I speculate that over-eating is one major mechanism for coping with this stress, and discuss the possibility that visceral fat may constitute an adaptive behaviour to the lower social hierarchy position, which is perceived as unjust. Connecting the prevalence of obesity to the narcissism epidemic allows for a more thorough examination of factors, which contribute to obesity, which includes early difficult childhood experience, lower rank, and the overall competitive framework of the society. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

  19. Discrete stochastic analogs of Erlang epidemic models.

    Science.gov (United States)

    Getz, Wayne M; Dougherty, Eric R

    2018-12-01

    Erlang differential equation models of epidemic processes provide more realistic disease-class transition dynamics from susceptible (S) to exposed (E) to infectious (I) and removed (R) categories than the ubiquitous SEIR model. The latter is itself is at one end of the spectrum of Erlang SE[Formula: see text]I[Formula: see text]R models with [Formula: see text] concatenated E compartments and [Formula: see text] concatenated I compartments. Discrete-time models, however, are computationally much simpler to simulate and fit to epidemic outbreak data than continuous-time differential equations, and are also much more readily extended to include demographic and other types of stochasticity. Here we formulate discrete-time deterministic analogs of the Erlang models, and their stochastic extension, based on a time-to-go distributional principle. Depending on which distributions are used (e.g. discretized Erlang, Gamma, Beta, or Uniform distributions), we demonstrate that our formulation represents both a discretization of Erlang epidemic models and generalizations thereof. We consider the challenges of fitting SE[Formula: see text]I[Formula: see text]R models and our discrete-time analog to data (the recent outbreak of Ebola in Liberia). We demonstrate that the latter performs much better than the former; although confining fits to strict SEIR formulations reduces the numerical challenges, but sacrifices best-fit likelihood scores by at least 7%.

  20. Epidemic risk from cholera introductions into Mexico.

    Science.gov (United States)

    Moore, Sean M; Shannon, Kerry L; Zelaya, Carla E; Azman, Andrew S; Lessler, Justin

    2014-02-21

    Stemming from the 2010 cholera outbreak in Haiti, cholera transmission in Hispaniola continues with over 40,000 cases in 2013. The presence of an ongoing cholera outbreak in the region poses substantial risks to countries throughout the Americas, particularly in areas with poor infrastructure. Since September 9, 2013 nearly 200 cholera cases have been reported in Mexico, as a result of introductions from Hispaniola or Cuba. There appear to have been multiple introductions into Mexico resulting in outbreaks of 2 to over 150 people. Using publicly available data, we attempt to estimate the reproductive number (R) of cholera in Mexico, and thereby assess the potential of continued introductions to establish a sustained epidemic. We estimate R for cholera in Mexico to be between 0.8 to 1.1, depending on the number of introductions, with the confidence intervals for the most plausible estimates crossing 1. These results suggest that the efficiency of cholera transmission in some regions of Mexico is near that necessary for a large epidemic. Intensive surveillance, evaluation of water and sanitation infrastructure, and planning for rapid response are warranted steps to avoid potential large epidemics in the region.

  1. Inferring epidemic network topology from surveillance data.

    Directory of Open Access Journals (Sweden)

    Xiang Wan

    Full Text Available The transmission of infectious diseases can be affected by many or even hidden factors, making it difficult to accurately predict when and where outbreaks may emerge. One approach at the moment is to develop and deploy surveillance systems in an effort to detect outbreaks as timely as possible. This enables policy makers to modify and implement strategies for the control of the transmission. The accumulated surveillance data including temporal, spatial, clinical, and demographic information, can provide valuable information with which to infer the underlying epidemic networks. Such networks can be quite informative and insightful as they characterize how infectious diseases transmit from one location to another. The aim of this work is to develop a computational model that allows inferences to be made regarding epidemic network topology in heterogeneous populations. We apply our model on the surveillance data from the 2009 H1N1 pandemic in Hong Kong. The inferred epidemic network displays significant effect on the propagation of infectious diseases.

  2. Cyanobacteria facilitate parasite epidemics in Daphnia.

    Science.gov (United States)

    Tellenbach, C; Tardent, N; Pomati, F; Keller, B; Hairston, N G; Wolinska, J; Spaak, P

    2016-12-01

    The seasonal dominance of cyanobacteria in the phytoplankton community of lake ecosystems can have severe implications for higher trophic levels. For herbivorous zooplankton such as Daphnia, cyanobacteria have poor nutritional value and some species can produce toxins affecting zooplankton survival and reproduction. Here we present another, hitherto largely unexplored aspect of cyanobacteria, namely that they can increase Daphnia susceptibility to parasites. In a 12-yr monthly time-series analysis of the Daphnia community in Greifensee (Switzerland), we observed that cyanobacteria density correlated significantly with the epidemics of a common gut parasite of Daphnia, Caullerya mesnili, regardless of what cyanobacteria species was present or whether it was colonial or filamentous. The temperature from the previous month also affected the occurrence of Caullerya epidemics, either directly or indirectly by the promotion of cyanobacterial growth. A laboratory experiment confirmed that cyanobacteria increase the susceptibility of Daphnia to Caullerya, and suggested a possible involvement of cyanotoxins or other chemical traits of cyanobacteria in this process. These findings expand our understanding of the consequences of toxic cyanobacterial blooms for lake ecosystems and might be relevant for epidemics experienced by other aquatic species. © 2016 by the Ecological Society of America.

  3. [Fight against epidemics: Austrian prisoners in Troyes].

    Science.gov (United States)

    Hetzel, Géraldine

    2014-01-01

    The victories near Ulm and Elchingen, where the Napoleonic army took 60000 prisoners between 15th and 20th of October 1805, lead to the arrival at Troyes (county "Aube") of nearly 2000 Austrian soldiers to be held inside former monasteries among whose, mainly the Jacobinians casern where more than half of them stayed. At the beginning of 1806, the government sent the epidemics medical practitioner Dr Desgenettes on an inspection tour to control the state of health of the populations of places where foreign prisoners were held, which lead him through several counties of the North-eastern part of France, where he surveyed several diseases ranging from all kinds offevers up to dysentery, scabies or gangrenes. With the means of acid fumigations invented by the chemist Guyton Morveau from Dijon, the authorities took care of combating and preventing the epidemics in the caserns. As soon as October 1805, the epidemics medical practitioner Dr Pigeotte from Troyes wrote to the county governor his observations recommending a better diet, airing of the rooms and also calls to take some exercise. All these precepts showed an astonishing modernity.

  4. Impacts of clustering on interacting epidemics.

    Science.gov (United States)

    Wang, Bing; Cao, Lang; Suzuki, Hideyuki; Aihara, Kazuyuki

    2012-07-07

    Since community structures in real networks play a major role for the epidemic spread, we therefore explore two interacting diseases spreading in networks with community structures. As a network model with community structures, we propose a random clique network model composed of different orders of cliques. We further assume that each disease spreads only through one type of cliques; this assumption corresponds to the issue that two diseases spread inside communities and outside them. Considering the relationship between the susceptible-infected-recovered (SIR) model and the bond percolation theory, we apply this theory to clique random networks under the assumption that the occupation probability is clique-type dependent, which is consistent with the observation that infection rates inside a community and outside it are different, and obtain a number of statistical properties for this model. Two interacting diseases that compete the same hosts are also investigated, which leads to a natural generalization of analyzing an arbitrary number of infectious diseases. For two-disease dynamics, the clustering effect is hypersensitive to the cohesiveness and concentration of cliques; this illustrates the impacts of clustering and the composition of subgraphs in networks on epidemic behavior. The analysis of coexistence/bistability regions provides significant insight into the relationship between the network structure and the potential epidemic prevalence. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Invited review: Epidemics on social networks

    Directory of Open Access Journals (Sweden)

    M. N. Kuperman

    2013-01-01

    Full Text Available Since its first formulations almost a century ago, mathematical models fordisease spreading contributed to understand, evaluate and control the epidemic processes.They promoted a dramatic change in how epidemiologists thought of the propagation of infectious diseases.In the last decade, when the traditional epidemiological models seemed to be exhausted, new types of models were developed.These new models incorporated concepts from graph theory to describe and model the underlying social structure.Many of these works merely produced a more detailed extension of the previous results, but some otherstriggered a completely new paradigm in the mathematical study of epidemic processes. In this review, we will introduce the basicconcepts of epidemiology, epidemic modeling and networks, to finally provide a brief description of the mostrelevant results in the field.Received: 6 April 2013, Accepted: 3 June 2013; Edited by: G. Mindlin; DOI: http://dx.doi.org/10.4279/PIP.050003Cite as: M N Kuperman, Papers in Physics 5, 050003 (2013

  6. Epidemics in partially overlapped multiplex networks.

    Directory of Open Access Journals (Sweden)

    Camila Buono

    Full Text Available Many real networks exhibit a layered structure in which links in each layer reflect the function of nodes on different environments. These multiple types of links are usually represented by a multiplex network in which each layer has a different topology. In real-world networks, however, not all nodes are present on every layer. To generate a more realistic scenario, we use a generalized multiplex network and assume that only a fraction [Formula: see text] of the nodes are shared by the layers. We develop a theoretical framework for a branching process to describe the spread of an epidemic on these partially overlapped multiplex networks. This allows us to obtain the fraction of infected individuals as a function of the effective probability that the disease will be transmitted [Formula: see text]. We also theoretically determine the dependence of the epidemic threshold on the fraction [Formula: see text] of shared nodes in a system composed of two layers. We find that in the limit of [Formula: see text] the threshold is dominated by the layer with the smaller isolated threshold. Although a system of two completely isolated networks is nearly indistinguishable from a system of two networks that share just a few nodes, we find that the presence of these few shared nodes causes the epidemic threshold of the isolated network with the lower propagating capacity to change discontinuously and to acquire the threshold of the other network.

  7. Mechanistic movement models to understand epidemic spread.

    Science.gov (United States)

    Fofana, Abdou Moutalab; Hurford, Amy

    2017-05-05

    An overlooked aspect of disease ecology is considering how and why animals come into contact with one and other resulting in disease transmission. Mathematical models of disease spread frequently assume mass-action transmission, justified by stating that susceptible and infectious hosts mix readily, and foregoing any detailed description of host movement. Numerous recent studies have recorded, analysed and modelled animal movement. These movement models describe how animals move with respect to resources, conspecifics and previous movement directions and have been used to understand the conditions for the occurrence and the spread of infectious diseases when hosts perform a type of movement. Here, we summarize the effect of the different types of movement on the threshold conditions for disease spread. We identify gaps in the literature and suggest several promising directions for future research. The mechanistic inclusion of movement in epidemic models may be beneficial for the following two reasons. Firstly, the estimation of the transmission coefficient in an epidemic model is possible because animal movement data can be used to estimate the rate of contacts between conspecifics. Secondly, unsuccessful transmission events, where a susceptible host contacts an infectious host but does not become infected can be quantified. Following an outbreak, this enables disease ecologists to identify 'near misses' and to explore possible alternative epidemic outcomes given shifts in ecological or immunological parameters.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'. © 2017 The Author(s).

  8. Epidemic optic neuropathy in Cuba. Eye findings.

    Science.gov (United States)

    Sadun, A A; Martone, J F; Muci-Mendoza, R; Reyes, L; DuBois, L; Silva, J C; Roman, G; Caballero, B

    1994-05-01

    To characterize and establish a clinical definition of the optic neuropathy that appeared in epidemic form in Cuba in 1992 and 1993. At the invitation of the Cuban Ministry of Health, Havana, members of ORBIS International and the Pan American Health Organization, assembled teams that traveled to Cuba in May 1993. We were initially briefed by Cuban national experts in the areas of virology, nutrition, toxicology, ophthalmology, neurology, and public health. We then examined 20 patients on our own. Thirteen of these patients underwent a comprehensive neuro-ophthalmologic examination, including neurologic examination, ophthalmologic examination, visual fields, optic nerve function studies, contrast sensitivity studies, and funduscopy. We returned 4 months later to perform an additional 12 comprehensive neuro-ophthalmologic and follow-up examinations. Only seven of the 13 patients who were alleged to have the optic form of the epidemic and who were rigorously and systematically examined on the first visit demonstrated a bilateral optic neuropathy. These seven patients had several features that included decreased visual acuity, poor color vision, central scotomas, decreased contrast sensitivity, saccadic eye movements, and most prominent and distinctive of all, nerve fiber layer wedge defects of the papillomacular bundle. Our clinical definition was then implemented by the Cuban ophthalmologists and epidemiologists. On returning 4 months later, we found that all newly presented patients were correctly diagnosed to have the epidemic disease. With the new case definition and the application of a few simple psychophysical tests, the false-positive rate of diagnosis became much lower. After vitamin therapy, we reexamined the patients seen on our initial visit, and all showed marked improvement. The Cuban epidemic was characterized by an optic neuropathy with features that were similar to those of tobacco/alcohol amblyopia and Leber's optic atrophy. Recent political

  9. Using Internet Artifacts to Profile a Child Pornography Suspect

    OpenAIRE

    Marcus K. Rogers; Kathryn C. Seigfried-Spellar

    2014-01-01

    Digital evidence plays a crucial role in child pornography investigations. However, in the following case study, the authors argue that the behavioral analysis or “profiling” of digital evidence can also play a vital role in child pornography investigations. The following case study assessed the Internet Browsing History (Internet Explorer Bookmarks, Mozilla Bookmarks, and Mozilla History) from a suspected child pornography user’s computer. The suspect in this case claimed to be conducting an...

  10. Talking heads : interviewing suspects from a cultural perspective

    OpenAIRE

    Beune, K.

    2009-01-01

    Although the literature on the interviewing of suspects has increased over the past decade, research on the use and effectiveness of police strategies and their boundary conditions is very rare. The present dissertation aims to fill this void by identifying behaviors that appeal to and persuade suspects to talk (i.e., influencing behavior), focusing on the effects of such behaviors and their dependency on cultural context (low-context vs. high-context). In doing so, we depart from a theoretic...

  11. Aerial medical evacuation of health workers with suspected Ebola virus disease in Guinea Conakry-interest of a negative pressure isolation pod-a case series.

    Science.gov (United States)

    Dindart, Jean-Michel; Peyrouset, Olivier; Palich, Romain; Bing, Abdoul; Kojan, Richard; Barbe, Solenne; Harouna, Souley; Blackwell, Nikki

    2017-03-11

    We report 4 cases of Health Workers (HW) suspected of having contracted Ebola Virus Disease (EVD), transported from the Alliance for International Medical Action (ALIMA) Ebola Treatment Centre (ETC) in N'Zerekore, Guinea to the Treatment Centre for Carers run by the medical corps of the French army in Conakry, the capital of Guinea, which was established on 17 January 2015 and closed on 7 July 2015. In total more than 500 HWs have died from EVD since the epidemic began. This mortality has had significant effects on the ability of local services to respond appropriately to the disaster. The HWs were transported by air in the "Human Stretcher Transit Isolator-Total Containment (Oxford) Limited" (HSTI-TCOL) negative pressure isolation pod. Medical evacuation of patients with suspected, potentially fatal, infectious diseases is feasible with the use of a light isolator for patients without critical dysfunctions.

  12. The risk of blood transfusion-associated Chikungunya fever during the 2009 epidemic in Songkhla Province, Thailand.

    Science.gov (United States)

    Appassakij, Hatsadee; Promwong, Charuporn; Rujirojindakul, Pairaya; Wutthanarungsan, Rochana; Silpapojakul, Khachornsakdi

    2014-08-01

    Asymptomatic Chikungunya fever (CHIKF)-viremic blood donors could be a potential threat of spreading the disease unwittingly through contaminated blood transfusions. The relatively low prevalence of Chikungunya virus antibodies in the population and the records of more than 9000 suspected CHIKF cases raised concern about the potential transfusion-associated CHIKF during the 2009 epidemic. This study assessed the potential transfusion risk for CHIKF and the implementation of blood safety measures to mitigate this risk. A probabilistic model using key variables obtained from local information was used to estimate the weekly risk of transfusion-associated CHIKF during the 2009 epidemic. In addition, other blood safety measure-based strategies involving screening for donors at risk, donor tracing, and a 7-day quarantine of blood components at risk were implemented at the time of the epidemic. The risk of viremic donations per 100,000 ranged from 38.2 (95% confidence interval [CI], 36.5-39.8) to 52.3 (95% CI, 50.4-54.2). The potential risk of transfusion-associated CHIKF per 100,000 was estimated to be 1 in 2429 (0.04%; 95% CI, 1 in 6681 [0.02%]-1 in 1572 [0.06%]) to 1 in 1781 (0.06%; 95% CI, 1 in 3817 [0.03%]-1 in 1214 (0.08%]) donations. Among 26,722 donations, 11 (95% CI, 4-17) to 15 (95% CI, 7-22) donations were predicted to associate with transfusion risk. The implementation of blood safety measure-based strategies for this epidemic period suggested to deter 11 blood donations of transfusion risk. The interventions for blood safety measures applied in this study had mitigated the potential transfusion-associated CHIKF during the 2009 epidemic. © 2014 AABB.

  13. Interviewing strategically to elicit admissions from guilty suspects.

    Science.gov (United States)

    Tekin, Serra; Granhag, Pär Anders; Strömwall, Leif; Giolla, Erik Mac; Vrij, Aldert; Hartwig, Maria

    2015-06-01

    In this article we introduce a novel interviewing tactic to elicit admissions from guilty suspects. By influencing the suspects' perception of the amount of evidence the interviewer holds against them, we aimed to shift the suspects' counterinterrogation strategies from less to more forthcoming. The proposed tactic (SUE-Confrontation) is a development of the Strategic Use of Evidence (SUE) framework and aims to affect the suspects' perception by confronting them with statement-evidence inconsistencies. Participants (N = 90) were asked to perform several mock criminal tasks before being interviewed using 1 of 3 interview techniques: (a) SUE-Confrontation, (b) Early Disclosure of Evidence, or (c) No Disclosure of Evidence. As predicted, the SUE-Confrontation interview generated more statement-evidence inconsistencies from suspects than the Early Disclosure interview. Importantly, suspects in the SUE-Confrontation condition (vs. Early and No disclosure conditions) admitted more self-incriminating information and also perceived the interviewer to have had more information about the critical phase of the crime (the phase where the interviewer lacked evidence). The findings show the adaptability of the SUE-technique and how it may be used as a tool for eliciting admissions. (c) 2015 APA, all rights reserved).

  14. Influence of Media on Seasonal Influenza Epidemic Curves.

    Science.gov (United States)

    Saito, Satoshi; Saito, Norihiro; Itoga, Masamichi; Ozaki, Hiromi; Kimura, Toshiyuki; Okamura, Yuji; Murakami, Hiroshi; Kayaba, Hiroyuki

    2016-09-01

    Theoretical investigations predicting the epidemic curves of seasonal influenza have been demonstrated so far; however, there is little empirical research using ever accumulated epidemic curves. The effects of vaccine coverage and information distribution on influenza epidemics were evaluated. Four indices for epidemics (i.e., onset-peak duration, onset-end duration, ratio of the onset-peak duration to onset-end duration and steepness of epidemic curves) were defined, and the correlations between these indices and anti-flu drug prescription dose, vaccine coverage, the volume of media and search trend on influenza through internet were analyzed. Epidemiological data on seasonal influenza epidemics from 2002/2003 to 2013/2014 excluding 2009/2010 season were collected from National Institute of Infectious Diseases of Japan. The onset-peak duration and its ratio to onset-end duration correlated inversely with the volume of anti-flu drug prescription. Onset-peak duration correlated positively with media information volume on influenza. The steepness of the epidemic curve, and anti-flu drug prescription dose inversely correlated with the volume of media information. Pre-epidemic search trend and media volume on influenza correlated with the vaccine coverage in the season. Vaccine coverage had no strong effect on epidemic curve. Education through media has an effect on the epidemic curve of seasonal influenza. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  15. Defining and detecting malaria epidemics in south-east Iran

    Directory of Open Access Journals (Sweden)

    McKelvie William R

    2012-03-01

    Full Text Available Abstract Background A lack of consensus on how to define malaria epidemics has impeded the evaluation of early detection systems. This study aimed to develop local definitions of malaria epidemics in a known malarious area of Iran, and to use that definition to evaluate the validity of several epidemic alert thresholds. Methods Epidemic definition variables generated from surveillance data were plotted against weekly malaria counts to assess which most accurately labelled aberrations. Various alert thresholds were then generated from weekly counts or log counts. Finally, the best epidemic definition was used to calculate and compare sensitivities, specificities, detection delays, and areas under ROC curves of the alert thresholds. Results The best epidemic definition used a minimum duration of four weeks and week-specific and overall smoothed geometric means plus 1.0 standard deviation. It defined 13 epidemics. A modified C-SUM alert of untransformed weekly counts using a threshold of mean + 0.25 SD had the highest combined sensitivity and specificity. Untransformed C-SUM alerts also had the highest area under the ROC curve. Conclusions Defining local malaria epidemics using objective criteria facilitated the evaluation of alert thresholds. This approach needs further study to refine epidemic definitions and prospectively evaluate epidemic alerts.

  16. Defining and detecting malaria epidemics in south-east Iran.

    Science.gov (United States)

    McKelvie, William R; Haghdoost, Ali Akbar; Raeisi, Ahmad

    2012-03-23

    A lack of consensus on how to define malaria epidemics has impeded the evaluation of early detection systems. This study aimed to develop local definitions of malaria epidemics in a known malarious area of Iran, and to use that definition to evaluate the validity of several epidemic alert thresholds. Epidemic definition variables generated from surveillance data were plotted against weekly malaria counts to assess which most accurately labelled aberrations. Various alert thresholds were then generated from weekly counts or log counts. Finally, the best epidemic definition was used to calculate and compare sensitivities, specificities, detection delays, and areas under ROC curves of the alert thresholds. The best epidemic definition used a minimum duration of four weeks and week-specific and overall smoothed geometric means plus 1.0 standard deviation. It defined 13 epidemics. A modified C-SUM alert of untransformed weekly counts using a threshold of mean+0.25 SD had the highest combined sensitivity and specificity. Untransformed C-SUM alerts also had the highest area under the ROC curve. Defining local malaria epidemics using objective criteria facilitated the evaluation of alert thresholds. This approach needs further study to refine epidemic definitions and prospectively evaluate epidemic alerts.

  17. An epidemic model for the future progression of the current Haiti cholera epidemic

    Science.gov (United States)

    Bertuzzo, E.; Mari, L.; Righetto, L.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2012-04-01

    As a major cholera epidemic progresses in Haiti, and the figures of the infection, up to December 2011, climb to 522,000 cases and 7,000 deaths, the development of general models to track and predict the evolution of the outbreak, so as to guide the allocation of medical supplies and staff, is gaining notable urgency. We propose here a spatially explicit epidemic model that accounts for the dynamics of susceptible and infected individuals as well as the redistribution of Vibrio cholera, the causative agent of the disease, among different human communities. In particular, we model two spreading pathways: the advection of pathogens through hydrologic connections and the dissemination due to human mobility described by means of a gravity-like model. To this end the country has been divided into hydrologic units based on drainage directions derived from a digital terrain model. Moreover the population of each unit has been estimated from census data downscaled to 1 km x 1 km resolution via remotely sensed geomorphological information (LandScan project). The model directly accounts for the role of rainfall patterns in driving the seasonality of cholera outbreaks. The two main outbreaks in fact occurred during the rainy seasons (October and May) when extensive floodings severely worsened the sanitation conditions and, in turn, raised the risk of infection. The model capability to reproduce the spatiotemporal features of the epidemic up to date grants robustness to the foreseen future development. To this end, we generate realistic scenario of future precipitation in order to forecast possible epidemic paths up to the end of the 2013. In this context, the duration of acquired immunity, a hotly debated topic in the scientific community, emerges as a controlling factor for progression of the epidemic in the near future. The framework presented here can straightforwardly be used to evaluate the effectiveness of alternative intervention strategies like mass vaccinations

  18. Dynamical Interplay between Awareness and Epidemic Spreading in Multiplex Networks

    Science.gov (United States)

    Granell, Clara; Gómez, Sergio; Arenas, Alex

    2013-09-01

    We present the analysis of the interrelation between two processes accounting for the spreading of an epidemic, and the information awareness to prevent its infection, on top of multiplex networks. This scenario is representative of an epidemic process spreading on a network of persistent real contacts, and a cyclic information awareness process diffusing in the network of virtual social contacts between the same individuals. The topology corresponds to a multiplex network where two diffusive processes are interacting affecting each other. The analysis using a microscopic Markov chain approach reveals the phase diagram of the incidence of the epidemics and allows us to capture the evolution of the epidemic threshold depending on the topological structure of the multiplex and the interrelation with the awareness process. Interestingly, the critical point for the onset of the epidemics has a critical value (metacritical point) defined by the awareness dynamics and the topology of the virtual network, from which the onset increases and the epidemics incidence decreases.

  19. Dynamical interplay between awareness and epidemic spreading in multiplex networks.

    Science.gov (United States)

    Granell, Clara; Gómez, Sergio; Arenas, Alex

    2013-09-20

    We present the analysis of the interrelation between two processes accounting for the spreading of an epidemic, and the information awareness to prevent its infection, on top of multiplex networks. This scenario is representative of an epidemic process spreading on a network of persistent real contacts, and a cyclic information awareness process diffusing in the network of virtual social contacts between the same individuals. The topology corresponds to a multiplex network where two diffusive processes are interacting affecting each other. The analysis using a microscopic Markov chain approach reveals the phase diagram of the incidence of the epidemics and allows us to capture the evolution of the epidemic threshold depending on the topological structure of the multiplex and the interrelation with the awareness process. Interestingly, the critical point for the onset of the epidemics has a critical value (metacritical point) defined by the awareness dynamics and the topology of the virtual network, from which the onset increases and the epidemics incidence decreases.

  20. Disease spreading with epidemic alert on small-world networks

    International Nuclear Information System (INIS)

    Han, Xiao-Pu

    2007-01-01

    Base on two-dimension small-world networks, a susceptible-infected model with epidemic alert is proposed in this Letter. In this model, if some parts of the network are alarmed as dangerous, a fraction of edges between the alarmed parts and others will be removed, and two cases of alerting rules that the degree and frequency of contacts kept unchanged are considered respectively. The numerical simulations show that the spreading velocity is reduced by the accurate and timely epidemic alert, and the more accurate and timely, the stronger the deceleration effect. This model indicates that to broadcast epidemic alert timely is helpful and necessary in the control of epidemic spreading, and in agreement with the general view of epidemic alert. This work is helpful to understand the effects of epidemic alert on disease spreading

  1. Cholera epidemics, war and disasters around Goma and Lake Kivu: an eight-year survey.

    Directory of Open Access Journals (Sweden)

    Didier Bompangue

    Full Text Available BACKGROUND: During the last eight years, North and South Kivu, located in a lake area in Eastern Democratic Republic of Congo, have been the site of a major volcano eruption and of numerous complex emergencies with population displacements. These conditions have been suspected to favour emergence and spread of cholera epidemics. METHODOLOGY/PRINCIPAL FINDINGS: In order to assess the influence of these conditions on outbreaks, reports of cholera cases were collected weekly from each health district of North Kivu (4,667,699 inhabitants and South Kivu (4,670,121 inhabitants from 2000 through 2007. A geographic information system was established, and in each health district, the relationships between environmental variables and the number of cholera cases were assessed using regression techniques and time series analysis. We further checked for a link between complex emergencies and cholera outbreaks. Finally, we analysed data collected during an epidemiological survey that was implemented in Goma after Nyiragongo eruption. A total of 73,605 cases and 1,612 deaths of cholera were reported. Time series decomposition showed a greater number of cases during the rainy season in South Kivu but not in North Kivu. Spatial distribution of cholera cases exhibited a higher number of cases in health districts bordering lakes (Odds Ratio 7.0, Confidence Interval range 3.8-12.9. Four epidemic reactivations were observed in the 12-week periods following war events, but simulations indicate that the number of reactivations was not larger than that expected during any random selection of period with no war. Nyiragongo volcanic eruption was followed by a marked decrease of cholera incidence. CONCLUSION/SIGNIFICANCE: Our study points out the crucial role of some towns located in lakeside areas in the persistence of cholera in Kivu. Even if complex emergencies were not systematically followed by cholera epidemics, some of them enabled cholera spreading.

  2. The spatial resolution of epidemic peaks.

    Directory of Open Access Journals (Sweden)

    Harriet L Mills

    2014-04-01

    Full Text Available The emergence of novel respiratory pathogens can challenge the capacity of key health care resources, such as intensive care units, that are constrained to serve only specific geographical populations. An ability to predict the magnitude and timing of peak incidence at the scale of a single large population would help to accurately assess the value of interventions designed to reduce that peak. However, current disease-dynamic theory does not provide a clear understanding of the relationship between: epidemic trajectories at the scale of interest (e.g. city; population mobility; and higher resolution spatial effects (e.g. transmission within small neighbourhoods. Here, we used a spatially-explicit stochastic meta-population model of arbitrary spatial resolution to determine the effect of resolution on model-derived epidemic trajectories. We simulated an influenza-like pathogen spreading across theoretical and actual population densities and varied our assumptions about mobility using Latin-Hypercube sampling. Even though, by design, cumulative attack rates were the same for all resolutions and mobilities, peak incidences were different. Clear thresholds existed for all tested populations, such that models with resolutions lower than the threshold substantially overestimated population-wide peak incidence. The effect of resolution was most important in populations which were of lower density and lower mobility. With the expectation of accurate spatial incidence datasets in the near future, our objective was to provide a framework for how to use these data correctly in a spatial meta-population model. Our results suggest that there is a fundamental spatial resolution for any pathogen-population pair. If underlying interactions between pathogens and spatially heterogeneous populations are represented at this resolution or higher, accurate predictions of peak incidence for city-scale epidemics are feasible.

  3. Epidemics on adaptive networks with geometric constraints

    Science.gov (United States)

    Shaw, Leah; Schwartz, Ira

    2008-03-01

    When a population is faced with an epidemic outbreak, individuals may modify their social behavior to avoid exposure to the disease. Recent work has considered models in which the contact network is rewired dynamically so that susceptibles avoid contact with infectives. We consider extensions in which the rewiring is subject to constraints that preserve key properties of the social network structure. Constraining to a fixed degree distribution destroys previously observed bistable behavior. The most effective rewiring strategy is found to depend on the spreading rate.

  4. Generalized epidemic process on modular networks.

    Science.gov (United States)

    Chung, Kihong; Baek, Yongjoo; Kim, Daniel; Ha, Meesoon; Jeong, Hawoong

    2014-05-01

    Social reinforcement and modular structure are two salient features observed in the spreading of behavior through social contacts. In order to investigate the interplay between these two features, we study the generalized epidemic process on modular networks with equal-sized finite communities and adjustable modularity. Using the analytical approach originally applied to clique-based random networks, we show that the system exhibits a bond-percolation type continuous phase transition for weak social reinforcement, whereas a discontinuous phase transition occurs for sufficiently strong social reinforcement. Our findings are numerically verified using the finite-size scaling analysis and the crossings of the bimodality coefficient.

  5. CHEMICAL VERSUS SERUM TREATMENT OF EPIDEMIC MENINGITIS.

    Science.gov (United States)

    Flexner, S; Amoss, H L

    1916-05-01

    Claims of efficiency have been made at two widely separated periods for the chemical treatment of epidemic meningitis, in the first instance for lysol and in the second for protargol. The use of lysol was long since abandoned; the recommendation for protargol is based on a single series of cases, small in number. Because of the variable severity of epidemics of meningitis, small reliance can be placed on results of treatment limited in extent to small numbers of cases and to one locality. A more uniform and accurate measure of the value of a method of treatment is provided by animals infected experimentally with pathogenic cultures of meningococci. Young guinea pigs respond in a definite manner to intraperitoneal inoculation of virulent meningococci. Neither protargol nor lysol proved to have any curative action on the experimental infection thus produced in these animals. Monkeys respond in a characteristic manner to the inoculation of virulent cultures into the subarachnoid space. Protargol displayed no curative action on the experimental infection thus produced in these animals. On the contrary, both lysol and protargol exert antileukotactic and antiphagocytic effects, and are also potent protoplasmic poisons, and the leukocytes with which they come in contact are injured and made to degenerate. According to the extent to which these harmful properties are exerted, the chemicals promote the advance rather than restrain the progress of meningococcic infection. Recovery from meningococcic infection in man and animals is accomplished chiefly through the process of phagocytosis. The specific antiserum acts curatively by increasing the emigration of leukocytes, by promoting phagocytosis directly, and by agglutinating the meningococci, and also by neutralizing endotoxin. Any means which interfere with and reduce these essential processes retard or prevent recovery. Both lysol and protargol interfere with and diminish the emigration of leukocytes and the phagocytosis

  6. Two approaches to forecast Ebola synthetic epidemics.

    Science.gov (United States)

    Champredon, David; Li, Michael; Bolker, Benjamin M; Dushoff, Jonathan

    2018-03-01

    We use two modelling approaches to forecast synthetic Ebola epidemics in the context of the RAPIDD Ebola Forecasting Challenge. The first approach is a standard stochastic compartmental model that aims to forecast incidence, hospitalization and deaths among both the general population and health care workers. The second is a model based on the renewal equation with latent variables that forecasts incidence in the whole population only. We describe fitting and forecasting procedures for each model and discuss their advantages and drawbacks. We did not find that one model was consistently better in forecasting than the other. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  7. Heterogeneous Epidemic Model for Assessing Data Dissemination in Opportunistic Networks

    DEFF Research Database (Denmark)

    Rozanova, Liudmila; Alekseev, Vadim; Temerev, Alexander

    2014-01-01

    that amount of data transferred between network nodes possesses a Pareto distribution, implying scale-free properties. In this context, more heterogeneity in susceptibility means the less severe epidemic progression, and, on the contrary, more heterogeneity in infectivity leads to more severe epidemics...... — assuming that the other parameter (either heterogeneity or susceptibility) stays fixed. The results are general enough to be useful for estimating the epidemic progression with no significant acquired immunity — in the cases where Pareto distribution holds....

  8. Hybrid epidemic spreading - from Internet worms to HIV infection

    OpenAIRE

    Zhang, C.

    2015-01-01

    Epidemic phenomena are ubiquitous, ranging from infectious diseases, computer viruses, to information dissemination. Epidemics have traditionally been studied as a single spreading process, either in a fully mixed population or on a network. Many epidemics, however, are hybrid, employing more than one spreading mechanism. For example, the Internet worm Conficker spreads locally targeting neighbouring computers in local networks as well as globally by randomly probing any computer on the Inter...

  9. Epidemic dynamics and endemic states in complex networks

    OpenAIRE

    Pastor-Satorras, Romualdo; Vespignani, Alessandro

    2001-01-01

    We study by analytical methods and large scale simulations a dynamical model for the spreading of epidemics in complex networks. In networks with exponentially bounded connectivity we recover the usual epidemic behavior with a threshold defining a critical point below which the infection prevalence is null. On the contrary, on a wide range of scale-free networks we observe the absence of an epidemic threshold and its associated critical behavior. This implies that scale-free networks are pron...

  10. Optimal Control of Interdependent Epidemics in Complex Networks

    OpenAIRE

    Chen, Juntao; Zhang, Rui; Zhu, Quanyan

    2017-01-01

    Optimal control of interdependent epidemics spreading over complex networks is a critical issue. We first establish a framework to capture the coupling between two epidemics, and then analyze the system's equilibrium states by categorizing them into three classes, and deriving their stability conditions. The designed control strategy globally optimizes the trade-off between the control cost and the severity of epidemics in the network. A gradient descent algorithm based on a fixed point itera...

  11. Epidemics: Lessons from the past and current patterns of response

    Science.gov (United States)

    Martin, Paul

    2008-09-01

    Hippocrates gave the term 'epidemic' its medical meaning. From antiquity to modern times, the meaning of the word epidemic has continued to evolve. Over the centuries, researchers have reached an understanding of the varying aspects of epidemics and have tried to combat them. The role played by travel, trade, and human exchanges in the propagation of epidemic infectious diseases has been understood. In 1948, the World Health Organization was created and given the task of advancing ways of combating epidemics. An early warning system to combat epidemics has been implemented by the WHO. The Global Outbreak Alert and Response Network (GOARN) is collaboration between existing institutions and networks that pool their human and technical resources to fight outbreaks. Avian influenza constitutes currently the most deadly epidemic threat, with fears that it could rapidly reach pandemic proportions and put several thousands of lives in jeopardy. Thanks to the WHO's support, most of the world's countries have mobilised and implemented an 'Action Plan for Pandemic Influenza'. As a result, most outbreaks of the H5N1 avian flu virus have so far been speedily contained. Cases of dengue virus introduction in countries possessing every circumstance required for its epidemic spread provide another example pertinent to the prevention of epidemics caused by vector-borne pathogens.

  12. Abia State HIV epidemic and response: challenges and prospects.

    Science.gov (United States)

    Onyeonoro, Ugochukwu Uchenna; Emelumadu, Obiageli Fidelia; Nwamoh, Uche Ngozi; Ukegbu, Andrew Ugwunna; Okafor, Godwin Oc

    2014-11-13

    Since the first seroprevalence survey in 1999, the HIV prevalence in Abia State has increased from 1.8% to 7.3% in 2010. The state is currently experiencing a generalized epidemic, with most transmission occurring through heterosexual low-risk sex. Drivers of the epidemic include low knowledge of HIV prevention, low risk perception, predominantly male factor-driven risky sexual behavior, and low condom use. This study reviewed the state HIV epidemic trend in relation to response, sought to identify the gaps between the epidemic and response, and recommended measures to strengthen the state response.

  13. Epidemic spreading on random surfer networks with infected avoidance strategy

    International Nuclear Information System (INIS)

    Feng Yun; Ding Li; Huang Yun-Han; Guan Zhi-Hong

    2016-01-01

    In this paper, we study epidemic spreading on random surfer networks with infected avoidance (IA) strategy. In particular, we consider that susceptible individuals’ moving direction angles are affected by the current location information received from infected individuals through a directed information network. The model is mainly analyzed by discrete-time numerical simulations. The results indicate that the IA strategy can restrain epidemic spreading effectively. However, when long-distance jumps of individuals exist, the IA strategy’s effectiveness on restraining epidemic spreading is heavily reduced. Finally, it is found that the influence of the noises from information transferring process on epidemic spreading is indistinctive. (paper)

  14. Epidemic spreading in time-varying community networks.

    Science.gov (United States)

    Ren, Guangming; Wang, Xingyuan

    2014-06-01

    The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold qc. The epidemic will survive when q > qc and die when q epidemic spreading in complex networks with community structure.

  15. Untangling the Interplay between Epidemic Spread and Transmission Network Dynamics.

    Directory of Open Access Journals (Sweden)

    Christel Kamp

    Full Text Available The epidemic spread of infectious diseases is ubiquitous and often has a considerable impact on public health and economic wealth. The large variability in the spatio-temporal patterns of epidemics prohibits simple interventions and requires a detailed analysis of each epidemic with respect to its infectious agent and the corresponding routes of transmission. To facilitate this analysis, we introduce a mathematical framework which links epidemic patterns to the topology and dynamics of the underlying transmission network. The evolution, both in disease prevalence and transmission network topology, is derived from a closed set of partial differential equations for infections without allowing for recovery. The predictions are in excellent agreement with complementarily conducted agent-based simulations. The capacity of this new method is demonstrated in several case studies on HIV epidemics in synthetic populations: it allows us to monitor the evolution of contact behavior among healthy and infected individuals and the contributions of different disease stages to the spreading of the epidemic. This gives both direction to and a test bed for targeted intervention strategies for epidemic control. In conclusion, this mathematical framework provides a capable toolbox for the analysis of epidemics from first principles. This allows for fast, in silico modeling--and manipulation--of epidemics and is especially powerful if complemented with adequate empirical data for parameterization.

  16. Dengue Deaths in Puerto Rico: Lessons Learned from the 2007 Epidemic

    Science.gov (United States)

    Tomashek, Kay M.; Gregory, Christopher J.; Rivera Sánchez, Aidsa; Bartek, Matthew A.; Garcia Rivera, Enid J.; Hunsperger, Elizabeth; Muñoz-Jordán, Jorge L.; Sun, Wellington

    2012-01-01

    Background The incidence and severity of dengue in Latin America has increased substantially in recent decades and data from Puerto Rico suggests an increase in severe cases. Successful clinical management of severe dengue requires early recognition and supportive care. Methods Fatal cases were identified among suspected dengue cases reported to two disease surveillance systems and from death certificates. To be included, fatal cases had to have specimen submitted for dengue diagnostic testing including nucleic acid amplification for dengue virus (DENV) in serum or tissue, immunohistochemical testing of tissue, and immunoassay detection of anti-DENV IgM from serum. Medical records from laboratory-positive dengue fatal case-patients were reviewed to identify possible determinants for death. Results Among 10,576 reported dengue cases, 40 suspect fatal cases were identified, of which 11 were laboratory-positive, 14 were laboratory-negative, and 15 laboratory-indeterminate. The median age of laboratory-positive case-patients was 26 years (range 5 months to 78 years), including five children aged Dengue was listed on the death certificate in only 5 instances. Conclusions During a dengue epidemic in an endemic area, none of the 11 laboratory-positive case-patients who died were managed according to current WHO Guidelines. Management issues identified in this case-series included failure to recognize warning signs for severe dengue and shock, prolonged ED stays, and infrequent patient monitoring. PMID:22530072

  17. Genetic Characterization of Northwestern Colombian Chikungunya Virus Strains from the 2014-2015 Epidemic.

    Science.gov (United States)

    Rodas, Juan D; Kautz, Tiffany; Camacho, Erwin; Paternina, Luis; Guzmán, Hilda; Díaz, Francisco J; Blanco, Pedro; Tesh, Robert; Weaver, Scott C

    2016-09-07

    Chikungunya fever, an acute and often chronic arthralgic disease caused by the mosquito-borne alphavirus, chikungunya virus (CHIKV), spread into the Americas in late 2013. Since then it has caused epidemics in nearly all New World countries, the second largest being Colombia with over 450,000 suspected cases beginning in September, 2014, and focused in Bolivar Department in the north. We examined 32 human sera from suspected cases, including diverse age groups and both genders, and sequenced the CHIKV envelope glycoprotein genes, known determinants of vector host range. As expected for Asian lineage CHIKV strains, these isolates lacked known Aedes albopictus-adaptive mutations. All the Colombian strains were closely related to those from the Virgin Islands, Saint Lucia, Mexico, Puerto Rico, and Brazil, consistent with a single, point-source introduction from the southeast Asia/Pacific region. Two substitutions in the E2 and E1 envelope glycoprotein genes were found in the Colombian strains, especially E1-K211E involving a residue shown previously to affect epistatically the penetrance of the E1-A226V A. albopictus-adaptive substitution. We also identified two amino acid substitutions unique to all American CHIKV sequences: E2-V368A and 6K-L20M. Only one codon, 6K-47, had a high nonsynonymous substitution rate suggesting positive selection. © The American Society of Tropical Medicine and Hygiene.

  18. Phenotypic and Genotypic Comparison of Epidemic and Non-Epidemic Strains of Pseudomonas aeruginosa from Individuals with Cystic Fibrosis.

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    Jessica Duong

    Full Text Available Epidemic strains of Pseudomonas aeruginosa have been found worldwide among the cystic fibrosis (CF patient population. Using pulse-field gel electrophoresis, the Prairie Epidemic Strain (PES has recently been found in one-third of patients attending the Calgary Adult CF Clinic in Canada. Using multi-locus sequence typing, PES isolates from unrelated patients were found to consistently have ST192. Though most patients acquired PES prior to enrolling in the clinic, some patients were observed to experience strain replacement upon transitioning to the clinic whereby local non-epidemic P. aeruginosa isolates were displaced by PES. Here we genotypically and phenotypically compared PES to other P. aeruginosa epidemic strains (OES found around the world as well as local non-epidemic CF P. aeruginosa isolates in order to characterize PES. Since some epidemic strains are associated with worse clinical outcomes, we assessed the pathogenic potential of PES to determine if these isolates are virulent, shared properties with OES, and if its phenotypic properties may offer a competitive advantage in displacing local non-epidemic isolates during strain replacement. As such, we conducted a comparative analysis using fourteen phenotypic traits, including virulence factor production, biofilm formation, planktonic growth, mucoidy, and antibiotic susceptibility to characterize PES, OES, and local non-epidemic isolates. We observed that PES and OES could be differentiated from local non-epidemic isolates based on biofilm growth with PES isolates being more mucoid. Pairwise comparisons indicated that PES produced significantly higher levels of proteases and formed better biofilms than OES but were more susceptible to antibiotic treatment. Amongst five patients experiencing strain replacement, we found that super-infecting PES produced lower levels of proteases and elastases but were more resistant to antibiotics compared to the displaced non-epidemic isolates. This

  19. The opioid overdose epidemic: opportunities for pharmacists

    Directory of Open Access Journals (Sweden)

    Wu LT

    2017-07-01

    Full Text Available Li-Tzy Wu,1–4 Udi E Ghitza,5 Anne L Burns,6 Paolo Mannelli,1 1Department of Psychiatry and Behavioral Sciences, 2Department of Medicine, 3Duke Clinical Research Institute, Duke University School of Medicine, 4Center for Child and Family Policy, Sanford School of Public Policy, Duke University, Durham, NC, 5Center for Clinical Trials Network, National Institute on Drug Abuse, Bethesda, MD, 6American Pharmacists Association, Washington, DC, USA The USA is experiencing an opioid overdose epidemic. It has been driven largely by prescription opioids and intensified by a surge of illicit opioids (e.g., heroin and fentanyl.1,2 Drug-involved overdose, mainly opioids (e.g., prescription opioids and heroin, is a leading cause of accidental death in the USA. The opioid overdose epidemic has been escalating consistently for over a decade.2 Every day, an estimated 91 Americans die from opioid-related overdose.3 Opioid overdose appears to have disproportionally affected men, adults aged 25–64 years, and non-Hispanic whites.2

  20. Resource allocation for epidemic control in metapopulations.

    Science.gov (United States)

    Ndeffo Mbah, Martial L; Gilligan, Christopher A

    2011-01-01

    Deployment of limited resources is an issue of major importance for decision-making in crisis events. This is especially true for large-scale outbreaks of infectious diseases. Little is known when it comes to identifying the most efficient way of deploying scarce resources for control when disease outbreaks occur in different but interconnected regions. The policy maker is frequently faced with the challenge of optimizing efficiency (e.g. minimizing the burden of infection) while accounting for social equity (e.g. equal opportunity for infected individuals to access treatment). For a large range of diseases described by a simple SIRS model, we consider strategies that should be used to minimize the discounted number of infected individuals during the course of an epidemic. We show that when faced with the dilemma of choosing between socially equitable and purely efficient strategies, the choice of the control strategy should be informed by key measurable epidemiological factors such as the basic reproductive number and the efficiency of the treatment measure. Our model provides new insights for policy makers in the optimal deployment of limited resources for control in the event of epidemic outbreaks at the landscape scale.

  1. [The cholera epidemic in Latin America].

    Science.gov (United States)

    Olsvik, O

    1992-05-30

    An outbreak of cholera started in Peru in January 1991 and spread through most Latin American countries within a year. This was the first known epidemic of cholera in America for more than a century. In 1991, 321,334 persons were reported to have cholera in Peru, 119,063 were hospitalized, and 2,906 died. Other countries like Ecuador, Colombia, Guatemala, Brazil, Mexico, Bolivia, Chile, El Salvador, Venezuela and Honduras were also affected, but these countries combined accounted for only 20% of the cases registered in Peru. In April 1992, all Latin American countries except Uruguay, Paraguay and French Guyana have reported cholera. The mortality rate for the epidemic in Latin America was only 1%, mainly owing to good oral rehydration treatment provided by Local health services and the Pan American Health Organization. The causative organism was Vibrio cholerae, serogroup O1, serotype Inaba (and Ogawa) of the El Tor biotype. Genetic characterization shows this strain to be unique, and the designation is reserved for the Latin American strain, distinguishing it from the other El Tor isolates from the 7th pandemic.

  2. Devastating epidemics in recent ages Greek populations.

    Science.gov (United States)

    Kotsiou, Antonia; Michalaki, Vasiliki; Anagnostopoulou, Helen N

    2017-12-01

    In the recent Greek ages the most devastating epidemics were plague, smallpox, leprosy and cholera. In 1816 plague struck the Ionian and Aegean Islands, mainland Greece, Constantinople and Smyrna. The Venetians ruling the Ionian Islands effectively combated plague in contrast to the Ottomans ruling all other regions. In 1922, plague appeared in Patras refugees who were expelled by the Turks from Smyrna and Asia Minor. Inoculation against smallpox was first performed in Thessaly by the Greek women, and the Greek doctors Emmanouel Timonis (1713, Oxford) and Jakovos Pylarinos (1715, Venice) made relevant scientific publications. The first leper colony opened in Chios Island. In Crete, Spinalonga was transformed into a leper island, which following the Independence War against Turkish occupation and the unification of Crete with Greece in 1913, was classified as an International Leper Hospital. Cholera struck Greece in 1853-1854 brought by the French troops during the Crimean War, and again during the Balkan Wars (1912-13) when the Bulgarian troops brought cholera to northern Greece. Due to successive wars, medical assistance was not always available, so desperate people turned many times to religion through processions in honor of local saints, for their salvation in epidemics.

  3. Resource allocation for epidemic control in metapopulations.

    Directory of Open Access Journals (Sweden)

    Martial L Ndeffo Mbah

    Full Text Available Deployment of limited resources is an issue of major importance for decision-making in crisis events. This is especially true for large-scale outbreaks of infectious diseases. Little is known when it comes to identifying the most efficient way of deploying scarce resources for control when disease outbreaks occur in different but interconnected regions. The policy maker is frequently faced with the challenge of optimizing efficiency (e.g. minimizing the burden of infection while accounting for social equity (e.g. equal opportunity for infected individuals to access treatment. For a large range of diseases described by a simple SIRS model, we consider strategies that should be used to minimize the discounted number of infected individuals during the course of an epidemic. We show that when faced with the dilemma of choosing between socially equitable and purely efficient strategies, the choice of the control strategy should be informed by key measurable epidemiological factors such as the basic reproductive number and the efficiency of the treatment measure. Our model provides new insights for policy makers in the optimal deployment of limited resources for control in the event of epidemic outbreaks at the landscape scale.

  4. America's Opioid Epidemic: Supply and Demand Considerations.

    Science.gov (United States)

    Clark, David J; Schumacher, Mark A

    2017-11-01

    America is in the midst of an opioid epidemic characterized by aggressive prescribing practices, highly prevalent opioid misuse, and rising rates of prescription and illicit opioid overdose-related deaths. Medical and lay public sentiment have become more cautious with respect to prescription opioid use in the past few years, but a comprehensive strategy to reduce our reliance on prescription opioids is lacking. Addressing this epidemic through reductions in unnecessary access to these drugs while implementing measures to reduce demand will be important components of any comprehensive solution. Key supply-side measures include avoiding overprescribing, reducing diversion, and discouraging misuse through changes in drug formulations. Important demand-side measures center around educating patients and clinicians regarding the pitfalls of opioid overuse and methods to avoid unnecessary exposure to these drugs. Anesthesiologists, by virtue of their expertise in the use of these drugs and their position in guiding opioid use around the time of surgery, have important roles to play in reducing patient exposure to opioids and providing education about appropriate use. Aside from the many immediate steps that can be taken, clinical and basic research directed at understanding the interaction between pain and opioid misuse is critical to identifying the optimal use of these powerful pain relievers in clinical practice.

  5. Epidemic contact tracing via communication traces.

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    Katayoun Farrahi

    Full Text Available Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks.

  6. Modelling the dynamics of nonendemic epidemics

    International Nuclear Information System (INIS)

    Ramani, A.; Grammaticos, B.; Satsuma, J.

    2009-01-01

    We present two models for an epidemic where the individuals are infective over a fixed period of time and which never becomes endemic i.e., no infective individuals remain after the epidemic has run its course. The first model is based on a delay-difference scheme. We show that, as a function of the delay (which corresponds to the period of infectiveness) the percentage of non-infected population varies over a wide range. We present also a variant of our model where the recovery rate follows a Poisson law and obtain a discrete version of the SIR model. We estimate the percentage of non-infected population in the two models, show that they lead to almost the same values and present an explanation of this fact. The second model is based on the assumption that the infection is spread by carriers. Under the hypothesis that the carriers are relatively long-lived, and that the number of the infected ones is a relatively small fraction of the total population of potential carriers, we show that the model reduces to the same version of the discrete SIR obtained by our first model.

  7. Modelling dengue epidemic spreading with human mobility

    Science.gov (United States)

    Barmak, D. H.; Dorso, C. O.; Otero, M.

    2016-04-01

    We explored the effect of human mobility on the spatio-temporal dynamics of Dengue with a stochastic model that takes into account the epidemiological dynamics of the infected mosquitoes and humans, with different mobility patterns of the human population. We observed that human mobility strongly affects the spread of infection by increasing the final size and by changing the morphology of the epidemic outbreaks. When the spreading of the disease is driven only by mosquito dispersal (flight), a main central focus expands diffusively. On the contrary, when human mobility is taken into account, multiple foci appear throughout the evolution of the outbreaks. These secondary foci generated throughout the outbreaks could be of little importance according to their mass or size compared with the largest main focus. However, the coalescence of these foci with the main one generates an effect, through which the latter develops a size greater than the one obtained in the case driven only by mosquito dispersal. This increase in growth rate due to human mobility and the coalescence of the foci are particularly relevant in temperate cities such as the city of Buenos Aires, since they give more possibilities to the outbreak to grow before the arrival of the low-temperature season. The findings of this work indicate that human mobility could be the main driving force in the dynamics of vector epidemics.

  8. Epidemic contact tracing via communication traces.

    Science.gov (United States)

    Farrahi, Katayoun; Emonet, Rémi; Cebrian, Manuel

    2014-01-01

    Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks.

  9. Colliding Epidemics and the Rise of Cryptococcosis

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    Christina C. Chang

    2015-12-01

    Full Text Available Discovered more than 100 years ago as a human pathogen, the Cryptococcus neoformans–Cryptococcus gattii (C. neoformans–C. gattii complex has seen a large global resurgence in its association with clinical disease in the last 30 years. First isolated in fermenting peach juice, and identified as a human pathogen in 1894 in a patient with bone lesions, this environmental pathogen has now found niches in soil, trees, birds, and domestic pets. Cryptococcosis is well recognized as an opportunistic infection and was first noted to be associated with reticuloendothelial cancers in the 1950s. Since then, advances in transplant immunology, medical science and surgical techniques have led to increasing numbers of solid organ transplantations (SOT and hematological stem cell transplantations being performed, and the use of biological immunotherapeutics in increasingly high-risk and older individuals, have contributed to the further rise in cryptococcosis. Globally, however, the major driver for revivification of cryptococcosis is undoubtedly the HIV epidemic, particularly in Sub-Saharan Africa where access to care and antiretroviral therapy remains limited and advanced immunodeficiency, poverty and malnutrition remains the norm. As a zoonotic disease, environmental outbreaks of both human and animal cryptococcosis have been reported, possibly driven by climate change. This is best exemplified by the resurgence of C. gattii infection in Vancouver Island, Canada, and the Pacific Northwest of the United States since 1999. Here we describe how the colliding epidemics of HIV, transplantation and immunologics, climate change and migration have contributed to the rise of cryptococcosis.

  10. Knowledge, Attitudes, and Practices Related to Ebola Virus Disease at the End of a National Epidemic - Guinea, August 2015.

    Science.gov (United States)

    Jalloh, Mohamed F; Robinson, Susan J; Corker, Jamaica; Li, Wenshu; Irwin, Kathleen; Barry, Alpha M; Ntuba, Paulyne Ngalame; Diallo, Alpha A; Jalloh, Mohammad B; Nyuma, James; Sellu, Musa; VanSteelandt, Amanda; Ramsden, Megan; Tracy, LaRee; Raghunathan, Pratima L; Redd, John T; Martel, Lise; Marston, Barbara; Bunnell, Rebecca

    2017-10-20

    Health communication and social mobilization efforts to improve the public's knowledge, attitudes, and practices (KAP) regarding Ebola virus disease (Ebola) were important in controlling the 2014-2016 Ebola epidemic in Guinea (1), which resulted in 3,814 reported Ebola cases and 2,544 deaths.* Most Ebola cases in Guinea resulted from the washing and touching of persons and corpses infected with Ebola without adequate infection control precautions at home, at funerals, and in health facilities (2,3). As the 18-month epidemic waned in August 2015, Ebola KAP were assessed in a survey among residents of Guinea recruited through multistage cluster sampling procedures in the nation's eight administrative regions (Boké, Conakry, Faranah, Kankan, Kindia, Labé, Mamou, and Nzérékoré). Nearly all participants (92%) were aware of Ebola prevention measures, but 27% believed that Ebola could be transmitted by ambient air, and 49% believed they could protect themselves from Ebola by avoiding mosquito bites. Of the participants, 95% reported taking actions to avoid getting Ebola, especially more frequent handwashing (93%). Nearly all participants (91%) indicated they would send relatives with suspected Ebola to Ebola treatment centers, and 89% said they would engage special Ebola burial teams to remove corpses with suspected Ebola from homes. Of the participants, 66% said they would prefer to observe an Ebola-affected corpse from a safe distance at burials rather than practice traditional funeral rites involving corpse contact. The findings were used to guide the ongoing epidemic response and recovery efforts, including health communication, social mobilization, and planning, to prevent and respond to future outbreaks or sporadic cases of Ebola.

  11. Clinical Survey of Dengue Virus Circulation in the Republic of Djibouti between 2011 and 2014 Identifies Serotype 3 Epidemic and Recommends Clinical Diagnosis Guidelines for Resource Limited Settings.

    Directory of Open Access Journals (Sweden)

    Erwan Le Gonidec

    2016-06-01

    Full Text Available Dengue virus is endemic globally, throughout tropical and sub-tropical regions. While the number of epidemics due to the four DENV serotypes is pronounced in East Africa, the total number of cases reported in Africa (16 million infections remained at low levels compared to Asia (70 million infections. The French Armed forces Health Service provides epidemiological surveillance support in the Republic of Djibouti through the Bouffard Military hospital. Between 2011 and 2014, clinical and biological data of suspected dengue syndromes were collected at the Bouffard Military hospital and analyzed to improve Dengue clinical diagnosis and evaluate its circulation in East Africa. Examining samples from patients that presented one or more Dengue-like symptoms the study evidenced 128 Dengue cases among 354 suspected cases (36.2% of the non-malarial Dengue-like syndromes. It also demonstrated the circulation of serotypes 1 and 2 and reports the first epidemic of serotype 3 infections in Djibouti which was found in all of the hospitalized patients in this study. Based on these results we have determined that screening for Malaria and the presence of the arthralgia, gastro-intestinal symptoms and lymphopenia < 1,000cell/ mm3 allows for negative predictive value and specificity of diagnosis in isolated areas superior to 80% up to day 6. This study also provides evidence for an epidemic of Dengue virus serotype 3 previously not detected in Djibouti.

  12. Accuracy of Zika virus disease case definition during simultaneous Dengue and Chikungunya epidemics.

    Science.gov (United States)

    Braga, José Ueleres; Bressan, Clarisse; Dalvi, Ana Paula Razal; Calvet, Guilherme Amaral; Daumas, Regina Paiva; Rodrigues, Nadia; Wakimoto, Mayumi; Nogueira, Rita Maria Ribeiro; Nielsen-Saines, Karin; Brito, Carlos; Bispo de Filippis, Ana Maria; Brasil, Patrícia

    2017-01-01

    Zika is a new disease in the American continent and its surveillance is of utmost importance, especially because of its ability to cause neurological manifestations as Guillain-Barré syndrome and serious congenital malformations through vertical transmission. The detection of suspected cases by the surveillance system depends on the case definition adopted. As the laboratory diagnosis of Zika infection still relies on the use of expensive and complex molecular techniques with low sensitivity due to a narrow window of detection, most suspected cases are not confirmed by laboratory tests, mainly reserved for pregnant women and newborns. In this context, an accurate definition of a suspected Zika case is crucial in order for the surveillance system to gauge the magnitude of an epidemic. We evaluated the accuracy of various Zika case definitions in a scenario where Dengue and Chikungunya viruses co-circulate. Signs and symptoms that best discriminated PCR confirmed Zika from other laboratory confirmed febrile or exanthematic diseases were identified to propose and test predictive models for Zika infection based on these clinical features. Our derived score prediction model had the best performance because it demonstrated the highest sensitivity and specificity, 86·6% and 78·3%, respectively. This Zika case definition also had the highest values for auROC (0·903) and R2 (0·417), and the lowest Brier score 0·096. In areas where multiple arboviruses circulate, the presence of rash with pruritus or conjunctival hyperemia, without any other general clinical manifestations such as fever, petechia or anorexia is the best Zika case definition.

  13. Accuracy of Zika virus disease case definition during simultaneous Dengue and Chikungunya epidemics.

    Directory of Open Access Journals (Sweden)

    José Ueleres Braga

    Full Text Available Zika is a new disease in the American continent and its surveillance is of utmost importance, especially because of its ability to cause neurological manifestations as Guillain-Barré syndrome and serious congenital malformations through vertical transmission. The detection of suspected cases by the surveillance system depends on the case definition adopted. As the laboratory diagnosis of Zika infection still relies on the use of expensive and complex molecular techniques with low sensitivity due to a narrow window of detection, most suspected cases are not confirmed by laboratory tests, mainly reserved for pregnant women and newborns. In this context, an accurate definition of a suspected Zika case is crucial in order for the surveillance system to gauge the magnitude of an epidemic.We evaluated the accuracy of various Zika case definitions in a scenario where Dengue and Chikungunya viruses co-circulate. Signs and symptoms that best discriminated PCR confirmed Zika from other laboratory confirmed febrile or exanthematic diseases were identified to propose and test predictive models for Zika infection based on these clinical features.Our derived score prediction model had the best performance because it demonstrated the highest sensitivity and specificity, 86·6% and 78·3%, respectively. This Zika case definition also had the highest values for auROC (0·903 and R2 (0·417, and the lowest Brier score 0·096.In areas where multiple arboviruses circulate, the presence of rash with pruritus or conjunctival hyperemia, without any other general clinical manifestations such as fever, petechia or anorexia is the best Zika case definition.

  14. Evaluation of laboratory tests for dengue diagnosis in clinical specimens from consecutive patients with suspected dengue in Belo Horizonte, Brazil.

    Science.gov (United States)

    Ferraz, Fernanda Oliveira; Bomfim, Maria Rosa Quaresma; Totola, Antônio Helvécio; Ávila, Thiago Vinícius; Cisalpino, Daniel; Pessanha, José Eduardo Marques; da Glória de Souza, Danielle; Teixeira Júnior, Antônio Lúcio; Nogueira, Maurício Lacerda; Bruna-Romero, Oscar; Teixeira, Mauro Martins

    2013-09-01

    Dengue is a widely spread arboviral disease in tropical and subtropical regions of the world. Dengue fever presents clinical characteristics similar to other febrile illness. Thus laboratory diagnosis is important for adequate management of the disease. The present study was designed to evaluate the diagnostic performance of real-time PCR and serological methods for dengue in a real epidemic context. Clinical data and blood samples were collected from consecutive patients with suspected dengue who attended a primary health care unit in Belo Horizonte, Brazil. Serologic methods and real-time PCR were performed in serum samples to confirm dengue diagnosis. Among the 181 consecutive patients enrolled in this study with suspected dengue, 146 were considered positive by serological criteria (positive NS1 ELISA and/or anti-dengue IgM ELISA) and 138 were positive by real-time PCR. Clinical criteria were not sufficient for distinguishing between dengue and non-dengue febrile illness. The PCR reaction was pre-optimized using samples from patients with known viral infection. It had similar sensitivity compared to NS1 ELISA (88% and 89%, respectively). We also evaluated three commercial lateral flow immunochromatographic tests for NS1 detection (BIOEASY, BIORAD and PANBIO). All three tests showed high sensitivity (94%, 91% and 81%, respectively) for dengue diagnosis. According to our results it can be suggested that lateral flow tests for NS1 detection are the most feasible methods for early diagnosis of dengue. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. The use of psychoactive prescription drugs among DUI suspects.

    Science.gov (United States)

    Karjalainen, Karoliina; Haukka, Jari; Lintonen, Tomi; Joukamaa, Matti; Lillsunde, Pirjo

    2015-10-01

    The study seeks to increase understanding of the use of psychoactive prescription drugs among persons suspected of driving under the influence (DUI). We studied whether the use of prescribed psychoactive medication was associated with DUI, and examined the difference in the use of prescription drugs between DUI recidivists and those arrested only once. In this register-based study, persons suspected of DUI (n=29470) were drawn from the Register of DUI suspects, and an age- and gender-matched reference population (n=30043) was drawn from the Finnish general population. Data on prescription drug use was obtained by linkage to the National Prescription Register. The associations of DUI arrest and use of psychoactive prescription drugs in different DUI groups (findings for alcohol only, prescription drugs, prescription drugs and alcohol, illicit drugs) were estimated by using mixed-effect logistic regression. The use of psychoactive prescription drugs and DUI appeared to be strongly associated, with DUI suspects significantly more likely to use psychoactive prescription drugs compared to the reference population. Gender differences existed, with the use of benzodiazepines being more common among female DUI suspects. Moreover, DUI recidivists were more likely to use psychoactive prescription drugs compared to those arrested only once. In addition to alcohol and/or illicit drug use, a significant proportion of DUI suspects were using psychoactive prescription drugs. When prescribing psychoactive medication, especially benzodiazepines, physicians are challenged to screen for possible substance use problems and also to monitor for patients' alcohol or illicit drug use while being medicated. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  16. Book Review: Placing the Suspect behind the Keyboard: Using Digital Forensics and Investigative Techniques to Identify Cybercrime Suspects

    Directory of Open Access Journals (Sweden)

    Thomas Nash

    2013-06-01

    Full Text Available Shavers, B. (2013. Placing the Suspect behind the Keyboard: Using Digital Forensics and Investigative Techniques to Identify Cybercrime Suspects. Waltham, MA: Elsevier, 290 pages, ISBN-978-1-59749-985-9, US$51.56. Includes bibliographical references and index.Reviewed by Detective Corporal Thomas Nash (tnash@bpdvt.org, Burlington Vermont Police Department, Internet Crime against Children Task Force. Adjunct Instructor, Champlain College, Burlington VT.In this must read for any aspiring novice cybercrime investigator as well as the seasoned professional computer guru alike, Brett Shaver takes the reader into the ever changing and dynamic world of Cybercrime investigation.  Shaver, an experienced criminal investigator, lays out the details and intricacies of a computer related crime investigation in a clear and concise manner in his new easy to read publication, Placing the Suspect behind the Keyboard. Using Digital Forensics and Investigative techniques to Identify Cybercrime Suspects. Shaver takes the reader from start to finish through each step of the investigative process in well organized and easy to follow sections, with real case file examples to reach the ultimate goal of any investigation: identifying the suspect and proving their guilt in the crime. Do not be fooled by the title. This excellent, easily accessible reference is beneficial to both criminal as well as civil investigations and should be in every investigator’s library regardless of their respective criminal or civil investigative responsibilities.(see PDF for full review

  17. A cost-effectiveness analysis of "test" versus "treat" patients hospitalized with suspected influenza in Hong Kong.

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    Joyce H S You

    Full Text Available BACKGROUND: Seasonal and 2009 H1N1 influenza viruses may cause severe diseases and result in excess hospitalization and mortality in the older and younger adults, respectively. Early antiviral treatment may improve clinical outcomes. We examined potential outcomes and costs of test-guided versus empirical treatment in patients hospitalized for suspected influenza in Hong Kong. METHODS: We designed a decision tree to simulate potential outcomes of four management strategies in adults hospitalized for severe respiratory infection suspected of influenza: "immunofluorescence-assay" (IFA or "polymerase-chain-reaction" (PCR-guided oseltamivir treatment, "empirical treatment plus PCR" and "empirical treatment alone". Model inputs were derived from literature. The average prevalence (11% of influenza in 2010-2011 (58% being 2009 H1N1 among cases of respiratory infections was used in the base-case analysis. Primary outcome simulated was cost per quality-adjusted life-year (QALY expected (ICER from the Hong Kong healthcare providers' perspective. RESULTS: In base-case analysis, "empirical treatment alone" was shown to be the most cost-effective strategy and dominated the other three options. Sensitivity analyses showed that "PCR-guided treatment" would dominate "empirical treatment alone" when the daily cost of oseltamivir exceeded USD18, or when influenza prevalence was <2.5% and the predominant circulating viruses were not 2009 H1N1. Using USD50,000 as the threshold of willingness-to-pay, "empirical treatment alone" and "PCR-guided treatment" were cost-effective 97% and 3% of time, respectively, in 10,000 Monte-Carlo simulations. CONCLUSIONS: During influenza epidemics, empirical antiviral treatment appears to be a cost-effective strategy in managing patients hospitalized with severe respiratory infection suspected of influenza, from the perspective of healthcare providers in Hong Kong.

  18. Virological confirmation of suspected dengue in a Phase 2 Latin American vaccine trial: Implications for vaccine efficacy evaluation

    Directory of Open Access Journals (Sweden)

    Mark Boaz

    2014-01-01

    Full Text Available The CYD tetravalent dengue vaccine candidate is being evaluated for protective efficacy against symptomatic dengue in Phase 3 efficacy trials. The laboratory test algorithm to confirm dengue cases was evaluated prior to Phase 3 trials. During a Phase 2 trial in Latin America a dengue epidemic occurred in the study countries. A total of 72 suspected dengue cases were reported and assessed: virological confirmation comprised qRT-PCR methods and a commercial ELISA kit for NS1 protein (Bio-Rad. The qRT-PCR included a screening assay targeting a conserved dengue region of the 3′-UTR (dengue screen assay followed by 4 individual serotype assays targeting the conserved dengue NS5 genomic region (WT dengue qRT-PCR assays. The NS1 and WT dengue qRT-PCR were endpoint assays for protocol virological confirmation (PVC. Of the 72 suspected cases, 14 were PVC. However, a unique pattern of dengue qRT-PCR results were observed in 5 suspected cases from Honduras: the dengue screen qRT-PCR assay was positive but WT dengue qRT-PCR and NS1 Ag ELISA were negative. To investigate these observations, additional molecular methods were applied: a SYBR® Green-based RT-PCR assay, sequencing assays directed at the genome regions covered by the WT dengue qRT-PCR, and a modified commercial dengue RT-PCR test (Simplexa™ Dengue, Focus Diagnostics. The exploratory data confirmed these additional cases as dengue and indicated the serotype 2 WT dengue qRT-PCR assay was unable to detect a circulating Latin American strain (DENV-2/NI/BID-V608/2006 due to a sequence variation in the isolate. The Simplexa Dengue RT-PCR test was able to detect and serotype dengue. Based on these findings an updated molecular test algorithm for the virological confirmation of dengue cases was developed and implemented in the Phase 3 efficacy trials.

  19. The origin and emergence of an HIV-1 epidemic:

    DEFF Research Database (Denmark)

    Bruhn, Christian Anders Wathne; Audelin, Anne M.; Helleberg, Marie

    2014-01-01

    To describe, at patient-level detail, the determining events and factors involved in the development of a country's HIV-1 epidemic.......To describe, at patient-level detail, the determining events and factors involved in the development of a country's HIV-1 epidemic....

  20. Stochastic analysis of epidemics on adaptive time varying networks

    Science.gov (United States)

    Kotnis, Bhushan; Kuri, Joy

    2013-06-01

    Many studies investigating the effect of human social connectivity structures (networks) and human behavioral adaptations on the spread of infectious diseases have assumed either a static connectivity structure or a network which adapts itself in response to the epidemic (adaptive networks). However, human social connections are inherently dynamic or time varying. Furthermore, the spread of many infectious diseases occur on a time scale comparable to the time scale of the evolving network structure. Here we aim to quantify the effect of human behavioral adaptations on the spread of asymptomatic infectious diseases on time varying networks. We perform a full stochastic analysis using a continuous time Markov chain approach for calculating the outbreak probability, mean epidemic duration, epidemic reemergence probability, etc. Additionally, we use mean-field theory for calculating epidemic thresholds. Theoretical predictions are verified using extensive simulations. Our studies have uncovered the existence of an “adaptive threshold,” i.e., when the ratio of susceptibility (or infectivity) rate to recovery rate is below the threshold value, adaptive behavior can prevent the epidemic. However, if it is above the threshold, no amount of behavioral adaptations can prevent the epidemic. Our analyses suggest that the interaction patterns of the infected population play a major role in sustaining the epidemic. Our results have implications on epidemic containment policies, as awareness campaigns and human behavioral responses can be effective only if the interaction levels of the infected populace are kept in check.

  1. The cholera epidemic in South Africa, 1980 - 1987 Epidemiological ...

    African Journals Online (AJOL)

    During the cholera epidemic in South Africa, 1980-1987, 25251 cases of cholera were bacteriologically proven. The case-fatality rate was 1,4%. Outbreaks occurred in the summer rainfall season. Age-specific aUack rates followed the pattern typically found during the 'epidemic phase' of the disease in most years. The vast ...

  2. [The cholera epidemic of 1833 and mortality in Mexico City].

    Science.gov (United States)

    Velasco, M D

    1992-01-01

    The author examines the impact of the 1833 cholera epidemic in Mexico City, Mexico, on social, economic, and political aspects of life in that city. She finds that some five percent of the population died during the epidemic, and enumerates them by age and sex.

  3. Unsynchronized influenza epidemics in two neighboring subtropical cities

    Directory of Open Access Journals (Sweden)

    Xiujuan Tang

    2018-04-01

    Full Text Available Objective: The aim of this study was to examine the synchrony of influenza epidemics between Hong Kong and Shenzhen, two neighboring subtropical cities in South China. Methods: Laboratory-confirmed influenza data for the period January 2006 to December 2016 were obtained from the Shenzhen Center for Disease Control and Prevention and the Department of Health in Hong Kong. The population data were retrieved from the 2011 population censuses. The weekly rates of laboratory-confirmed influenza cases were compared between Shenzhen and Hong Kong. Results: Unsynchronized influenza epidemics between Hong Kong and Shenzhen were frequently observed during the study period. Influenza A/H1N1 caused a more severe pandemic in Hong Kong in 2009, but the subsequent seasonal epidemics showed similar magnitudes in both cities. Two influenza A/H3N2 dominant epidemic waves were seen in Hong Kong in 2015, but these epidemics were very minor in Shenzhen. More influenza B epidemics occurred in Shenzhen than in Hong Kong. Conclusions: Influenza epidemics appeared to be unsynchronized between Hong Kong and Shenzhen most of the time. Given the close geographical locations of these two cities, this could be due to the strikingly different age structures of their populations. Keywords: Influenza epidemics, Synchrony, Shenzhen, Hong Kong

  4. The global spread of HIV-1 subtype B epidemic

    NARCIS (Netherlands)

    Magiorkinis, Gkikas; Angelis, Konstantinos; Mamais, Ioannis; Katzourakis, Aris; Hatzakis, Angelos; Albert, Jan; Lawyer, Glenn; Hamouda, Osamah; Struck, Daniel; Vercauteren, Jurgen; Wensing, Annemarie; Alexiev, Ivailo; Åsjö, Birgitta; Balotta, Claudia; Gomes, Perpétua; Camacho, Ricardo J.; Coughlan, Suzie; Griskevicius, Algirdas; Grossman, Zehava; Horban, Anders; Kostrikis, Leondios G.; Lepej, Snjezana J.; Liitsola, Kirsi; Linka, Marek; Nielsen, Claus; Otelea, Dan; Paredes, Roger; Poljak, Mario; Puchhammer-Stöckl, Elizabeth; Schmit, Jean Claude; Sönnerborg, Anders; Staneková, Danica; Stanojevic, Maja; Stylianou, Dora C.; Boucher, Charles A B; Nikolopoulos, Georgios; Vasylyeva, Tetyana; Friedman, Samuel R.; van de Vijver, David; Angarano, Gioacchino; Chaix, Marie Laure; de Luca, Andrea; Korn, Klaus; Loveday, Clive; Soriano, Vincent; Yerly, Sabine; Zazzi, Mauricio; Vandamme, Anne Mieke; Paraskevis, Dimitrios

    2016-01-01

    Human immunodeficiency virus type 1 (HIV-1) was discovered in the early 1980s when the virus had already established a pandemic. For at least three decades the epidemic in the Western World has been dominated by subtype B infections, as part of a sub-epidemic that traveled from Africa through Haiti

  5. On The Travelling Wave Solution For An SEIR Epidemic Disease ...

    African Journals Online (AJOL)

    We present the travelling wave solution for a Susceptible, Exposed, Infective and Removed (SEIR) epidemic disease model. For this SEIR model, the disease is driven by both the latent and infective class (the diffusion term is included in both classes). The population is closed. Keywords: Epidemic model, spatial spread, ...

  6. The fastest spreader in SIS epidemics on networks

    NARCIS (Netherlands)

    He, Z.; Van Mieghem, P.F.A.

    2018-01-01

    Identifying the fastest spreaders in epidemics on a network helps to ensure an efficient spreading. By ranking the average spreading time for different spreaders, we show that the fastest spreader may change with the effective infection rate of a SIS epidemic process, which means that the

  7. Effects of local and global network connectivity on synergistic epidemics

    Science.gov (United States)

    Broder-Rodgers, David; Pérez-Reche, Francisco J.; Taraskin, Sergei N.

    2015-12-01

    Epidemics in networks can be affected by cooperation in transmission of infection and also connectivity between nodes. An interplay between these two properties and their influence on epidemic spread are addressed in the paper. A particular type of cooperative effects (called synergy effects) is considered, where the transmission rate between a pair of nodes depends on the number of infected neighbors. The connectivity effects are studied by constructing networks of different topology, starting with lattices with only local connectivity and then with networks that have both local and global connectivity obtained by random bond-rewiring to nodes within a certain distance. The susceptible-infected-removed epidemics were found to exhibit several interesting effects: (i) for epidemics with strong constructive synergy spreading in networks with high local connectivity, the bond rewiring has a negative role in epidemic spread, i.e., it reduces invasion probability; (ii) in contrast, for epidemics with destructive or weak constructive synergy spreading on networks of arbitrary local connectivity, rewiring helps epidemics to spread; (iii) and, finally, rewiring always enhances the spread of epidemics, independent of synergy, if the local connectivity is low.

  8. The severe acute respiratory syndrome epidemic in mainland China dissected

    NARCIS (Netherlands)

    W.-C. Cao (Wu-Chun); S.J. de Vlas (Sake); J.H. Richardus (Jan Hendrik)

    2011-01-01

    textabstractThis paper provides a review of a recently published series of studies that give a detailed and comprehensive documentation of the severe acute respiratory syndrome (SARS) epidemic in mainland China, which severely struck the country in the spring of 2003. The epidemic spanned a large

  9. The global spread of HIV-1 subtype B epidemic

    NARCIS (Netherlands)

    G. Magiorkinis (Gkikas); K. Angelis (Konstantinos); I. Mamais (Ioannis); Katzourakis, A. (Aris); A. Hatzakis (Angelos); J. Albert (Jan); Lawyer, G. (Glenn); O. Hamouda (Osamah); D. Struck (Daniel); J. Vercauteren (Jurgen); A. Wensing (Amj); I. Alexiev (Ivailo); B. Åsjö (Birgitta); C. Balotta (Claudia); Gomes, P. (Perpétua); R.J. Camacho (Ricardo Jorge); S. Coughlan (Suzie); A. Griskevicius (Algirdas); Z. Grossman (Zehava); Horban, A. (Anders); L.G. Kostrikis (Leondios); Lepej, S.J. (Snjezana J.); K. Liitsola (Kirsi); M. Linka (Marek); C. Nielsen; D. Otelea (Dan); R. Paredes (Roger); M. Poljak (Mario); E. Puchhammer-Stöckl (Elisabeth); J.C. Schmit; A. Sonnerborg (Anders); D. Stanekova (Danica); M. Stanojevic (Maja); Stylianou, D.C. (Dora C.); C.A.B. Boucher (Charles); Nikolopoulos, G. (Georgios); Vasylyeva, T. (Tetyana); Friedman, S.R. (Samuel R.); D.A.M.C. van de Vijver (David); G. Angarano (Guiseppe); M.L. Chaix (Marie Laure); A. de Luca (Andrea); K. Korn (Klaus); Loveday, C. (Clive); V. Soriano (Virtudes); S. Yerly (Sabine); M. Zazzi; A.M. Vandamme (Anne Mieke); D. Paraskevis (Dimitrios)

    2016-01-01

    textabstractHuman immunodeficiency virus type 1 (HIV-1) was discovered in the early 1980s when the virus had already established a pandemic. For at least three decades the epidemic in the Western World has been dominated by subtype B infections, as part of a sub-epidemic that traveled from Africa

  10. Concurrency-Induced Transitions in Epidemic Dynamics on Temporal Networks.

    Science.gov (United States)

    Onaga, Tomokatsu; Gleeson, James P; Masuda, Naoki

    2017-09-08

    Social contact networks underlying epidemic processes in humans and animals are highly dynamic. The spreading of infections on such temporal networks can differ dramatically from spreading on static networks. We theoretically investigate the effects of concurrency, the number of neighbors that a node has at a given time point, on the epidemic threshold in the stochastic susceptible-infected-susceptible dynamics on temporal network models. We show that network dynamics can suppress epidemics (i.e., yield a higher epidemic threshold) when the node's concurrency is low, but can also enhance epidemics when the concurrency is high. We analytically determine different phases of this concurrency-induced transition, and confirm our results with numerical simulations.

  11. Concurrency-Induced Transitions in Epidemic Dynamics on Temporal Networks

    Science.gov (United States)

    Onaga, Tomokatsu; Gleeson, James P.; Masuda, Naoki

    2017-09-01

    Social contact networks underlying epidemic processes in humans and animals are highly dynamic. The spreading of infections on such temporal networks can differ dramatically from spreading on static networks. We theoretically investigate the effects of concurrency, the number of neighbors that a node has at a given time point, on the epidemic threshold in the stochastic susceptible-infected-susceptible dynamics on temporal network models. We show that network dynamics can suppress epidemics (i.e., yield a higher epidemic threshold) when the node's concurrency is low, but can also enhance epidemics when the concurrency is high. We analytically determine different phases of this concurrency-induced transition, and confirm our results with numerical simulations.

  12. Evaluating Subcriticality during the Ebola Epidemic in West Africa.

    Directory of Open Access Journals (Sweden)

    Wayne T A Enanoria

    Full Text Available The 2014-2015 Ebola outbreak is the largest and most widespread to date. In order to estimate ongoing transmission in the affected countries, we estimated the weekly average number of secondary cases caused by one individual infected with Ebola throughout the infectious period for each affected West African country using a stochastic hidden Markov model fitted to case data from the World Health Organization. If the average number of infections caused by one Ebola infection is less than 1.0, the epidemic is subcritical and cannot sustain itself. The epidemics in Liberia and Sierra Leone have approached subcriticality at some point during the epidemic; the epidemic in Guinea is ongoing with no evidence that it is subcritical. Response efforts to control the epidemic should continue in order to eliminate Ebola cases in West Africa.

  13. Dynamical processes and epidemic threshold on nonlinear coupled multiplex networks

    Science.gov (United States)

    Gao, Chao; Tang, Shaoting; Li, Weihua; Yang, Yaqian; Zheng, Zhiming

    2018-04-01

    Recently, the interplay between epidemic spreading and awareness diffusion has aroused the interest of many researchers, who have studied models mainly based on linear coupling relations between information and epidemic layers. However, in real-world networks the relation between two layers may be closely correlated with the property of individual nodes and exhibits nonlinear dynamical features. Here we propose a nonlinear coupled information-epidemic model (I-E model) and present a comprehensive analysis in a more generalized scenario where the upload rate differs from node to node, deletion rate varies between susceptible and infected states, and infection rate changes between unaware and aware states. In particular, we develop a theoretical framework of the intra- and inter-layer dynamical processes with a microscopic Markov chain approach (MMCA), and derive an analytic epidemic threshold. Our results suggest that the change of upload and deletion rate has little effect on the diffusion dynamics in the epidemic layer.

  14. The influence of school holiday timing on epidemic impact.

    Science.gov (United States)

    Eames, K T D

    2014-09-01

    The impact of reactive school closure on an epidemic is uncertain, since it is not clear how an unplanned closure will affect social mixing patterns. The effect of school holidays on social mixing patterns is better understood. Here, we use mathematical models to explore the influence of the timing of school holidays on the final size and peak incidence of an influenza-like epidemic. A well-timed holiday can reduce the impact of an epidemic, in particular substantially reducing an epidemic's peak. Final size and peak incidence cannot both be minimized: a later holiday is optimal for minimizing the final size, while an earlier holiday minimizes peak incidence. Using social mixing data from the UK, we estimated that, had the 2009 influenza epidemic not been interrupted by the school summer holidays, the final size would have been about 20% larger and the peak about 170% higher.

  15. Epidemic spreading between two coupled subpopulations with inner structures

    Science.gov (United States)

    Ruan, Zhongyuan; Tang, Ming; Gu, Changgui; Xu, Jinshan

    2017-10-01

    The structure of underlying contact network and the mobility of agents are two decisive factors for epidemic spreading in reality. Here, we study a model consisting of two coupled subpopulations with intra-structures that emphasizes both the contact structure and the recurrent mobility pattern of individuals simultaneously. We show that the coupling of the two subpopulations (via interconnections between them and round trips of individuals) makes the epidemic threshold in each subnetwork to be the same. Moreover, we find that the interconnection probability between two subpopulations and the travel rate are important factors for spreading dynamics. In particular, as a function of interconnection probability, the epidemic threshold in each subpopulation decreases monotonously, which enhances the risks of an epidemic. While the epidemic threshold displays a non-monotonic variation as travel rate increases. Moreover, the asymptotic infected density as a function of travel rate in each subpopulation behaves differently depending on the interconnection probability.

  16. Suppressing traffic-driven epidemic spreading by adaptive routing strategy

    International Nuclear Information System (INIS)

    Yang, Han-Xin; Wang, Zhen

    2016-01-01

    The design of routing strategies for traffic-driven epidemic spreading has received increasing attention in recent years. In this paper, we propose an adaptive routing strategy that incorporates topological distance with local epidemic information through a tunable parameter h. In the case where the traffic is free of congestion, there exists an optimal value of routing parameter h, leading to the maximal epidemic threshold. This means that epidemic spreading can be more effectively controlled by adaptive routing, compared to that of the static shortest path routing scheme. Besides, we find that the optimal value of h can greatly relieve the traffic congestion in the case of finite node-delivering capacity. We expect our work to provide new insights into the effects of dynamic routings on traffic-driven epidemic spreading.

  17. Epidemics and dimensionality in hierarchical networks

    Science.gov (United States)

    Zheng, Da-Fang; Hui, P. M.; Trimper, Steffen; Zheng, Bo

    2005-07-01

    Epidemiological processes are studied within a recently proposed hierarchical network model using the susceptible-infected-refractory dynamics of an epidemic. Within the network model, a population may be characterized by H independent hierarchies or dimensions, each of which consists of groupings of individuals into layers of subgroups. Detailed numerical simulations reveal that for H>1, global spreading results regardless of the degree of homophily of the individuals forming a social circle. For H=1, a transition from global to local spread occurs as the population becomes decomposed into increasingly homophilous groups. Multiple dimensions in classifying individuals (nodes) thus make a society (computer network) highly susceptible to large-scale outbreaks of infectious diseases (viruses).

  18. Social networks and spreading of epidemics

    Science.gov (United States)

    Trimper, Steffen; Zheng, Dafang; Brandau, Marian

    2004-05-01

    Epidemiological processes are studied within a recently proposed social network model using the susceptible-infected-refractory dynamics (SIR) of an epidemic. Within the network model, a population of individuals may be characterized by H independent hierarchies or dimensions, each of which consists of groupings of individuals into layers of subgroups. Detailed numerical simulations reveals that for H > 1, the global spreading results regardless of the degree of homophily α of the individuals forming a social circle. For H = 1, a transition from a global to a local spread occurs as the population becomes decomposed into increasingly homophilous groups. Multiple dimensions in classifying individuals (nodes) thus make a society (computer network) highly susceptible to large scale outbreaks of infectious diseases (viruses). The SIR-model can be extended by the inclusion of waiting times resulting in modified distribution function of the recovered.

  19. Quarantine generated phase transition in epidemic spreading

    Science.gov (United States)

    Dicksion, Mark; Lagorio, Cecilia; Vazquez, F.; Braunstein, L.; Macri, P. A.; Migueles, M. V.; Havlin, S.; Stanley, H. E.

    2011-03-01

    We study the critical effect of quarantine on the propagation of epidemics on an adaptive network of social contacts. For this purpose, we analyze the susceptible-infected-recovered (SIR) model in the presence of quarantine, where susceptible individuals protect themselves by disconnecting their links to infected neighbors with probability w, and reconnecting them to other susceptible individuals chosen at random. Starting from a single infected individual, we show by an analytical approach and simulations that there is a phase transition at a critical rewiring (quarantine) threshold wc separating a phase (w =wc) where the disease does not spread out. We find that in our model the topology of the network strongly affects the size of the propagation, and that wc increases with the mean degree and heterogeneity of the network. We also find that wc is reduced if we perform a preferential rewiring, in which the rewiring probability is proportional to the degree of infected nodes.

  20. Epidemic Dynamics in Open Quantum Spin Systems

    Science.gov (United States)

    Pérez-Espigares, Carlos; Marcuzzi, Matteo; Gutiérrez, Ricardo; Lesanovsky, Igor

    2017-10-01

    We explore the nonequilibrium evolution and stationary states of an open many-body system that displays epidemic spreading dynamics in a classical and a quantum regime. Our study is motivated by recent experiments conducted in strongly interacting gases of highly excited Rydberg atoms where the facilitated excitation of Rydberg states competes with radiative decay. These systems approximately implement open quantum versions of models for population dynamics or disease spreading where species can be in a healthy, infected or immune state. We show that in a two-dimensional lattice, depending on the dominance of either classical or quantum effects, the system may display a different kind of nonequilibrium phase transition. We moreover discuss the observability of our findings in laser driven Rydberg gases with particular focus on the role of long-range interactions.

  1. Multilingual event extraction for epidemic detection.

    Science.gov (United States)

    Lejeune, Gaël; Brixtel, Romain; Doucet, Antoine; Lucas, Nadine

    2015-10-01

    This paper presents a multilingual news surveillance system applied to tele-epidemiology. It has been shown that multilingual approaches improve timeliness in detection of epidemic events across the globe, eliminating the wait for local news to be translated into major languages. We present here a system to extract epidemic events in potentially any language, provided a Wikipedia seed for common disease names exists. The Daniel system presented herein relies on properties that are common to news writing (the journalistic genre), the most useful being repetition and saliency. Wikipedia is used to screen common disease names to be matched with repeated characters strings. Language variations, such as declensions, are handled by processing text at the character-level, rather than at the word level. This additionally makes it possible to handle various writing systems in a similar fashion. As no multilingual ground truth existed to evaluate the Daniel system, we built a multilingual corpus from the Web, and collected annotations from native speakers of Chinese, English, Greek, Polish and Russian, with no connection or interest in the Daniel system. This data set is available online freely, and can be used for the evaluation of other event extraction systems. Experiments for 5 languages out of 17 tested are detailed in this paper: Chinese, English, Greek, Polish and Russian. The Daniel system achieves an average F-measure of 82% in these 5 languages. It reaches 87% on BEcorpus, the state-of-the-art corpus in English, slightly below top-performing systems, which are tailored with numerous language-specific resources. The consistent performance of Daniel on multiple languages is an important contribution to the reactivity and the coverage of epidemiological event detection systems. Most event extraction systems rely on extensive resources that are language-specific. While their sophistication induces excellent results (over 90% precision and recall), it restricts their

  2. Genealogical evidence for epidemics of selfish genes.

    Science.gov (United States)

    Ingvarsson, Par K; Taylor, Douglas R

    2002-08-20

    Some genetic elements spread infectiously in populations by increasing their rate of genetic transmission at the expense of other genes in the genome. These so-called selfish genetic elements comprise a substantial portion of eukaryotic genomes and have long been viewed as a potent evolutionary force. Despite this view, little is known about the evolutionary history of selfish genetic elements in natural populations, or their genetic effects on other portions of the genome. Here we use nuclear and chloroplast gene genealogies in two species of Silene to show the historical pattern of selection on a well known selfish genetic element, cytoplasmic male sterility. We provide evidence that evolution of cytoplasmic male sterility has been characterized by frequent turnovers of mutations in natural populations, thus supporting an epidemic model for the evolution of selfish genes, where new mutations repeatedly arise and rapidly sweep through populations.

  3. Open data mining for Taiwan's dengue epidemic.

    Science.gov (United States)

    Wu, ChienHsing; Kao, Shu-Chen; Shih, Chia-Hung; Kan, Meng-Hsuan

    2018-07-01

    By using a quantitative approach, this study examines the applicability of data mining technique to discover knowledge from open data related to Taiwan's dengue epidemic. We compare results when Google trend data are included or excluded. Data sources are government open data, climate data, and Google trend data. Research findings from analysis of 70,914 cases are obtained. Location and time (month) in open data show the highest classification power followed by climate variables (temperature and humidity), whereas gender and age show the lowest values. Both prediction accuracy and simplicity decrease when Google trends are considered (respectively 0.94 and 0.37, compared to 0.96 and 0.46). The article demonstrates the value of open data mining in the context of public health care. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Chernobyl: Symptom of a worrying psychological epidemic

    International Nuclear Information System (INIS)

    Pretre, S.

    1991-01-01

    The Chernobyl psychological epidemic was already latent well prior to 1986 fully broke out after the accident, and continues to spread. It must be halted. But how can we counter a belief which has taken on the appearance of reality. It is the unknown, linked to alarming symbols, which sustains fear. To get beyond this state, radioactivity, ionizing radiation and nuclear energy have to become as ordinary as air travel and electronic calculators. In a climate of confidence and openness, it should be possible to successfully communicate several solid scientific reference points by first targeting teachers, doctors, and journalists. Thirty years ago, nuclear energy was presented as a universal panacea (clean, safe, and renewable). Now things have swung to the other extreme, and it is presented as diabolical. We have shifted from a symbolically white level to a symbolically black level, and both are misleading. It is high time to rejoin the world of facts, a world full of shades of gray

  5. A stochastic SIS epidemic model with vaccination

    Science.gov (United States)

    Cao, Boqiang; Shan, Meijing; Zhang, Qimin; Wang, Weiming

    2017-11-01

    In this paper, we investigate the basic features of an SIS type infectious disease model with varying population size and vaccinations in presence of environment noise. By applying the Markov semigroup theory, we propose a stochastic reproduction number R0s which can be seen as a threshold parameter to utilize in identifying the stochastic extinction and persistence: If R0s disease-free absorbing set for the stochastic epidemic model, which implies that disease dies out with probability one; while if R0s > 1, under some mild extra conditions, the SDE model has an endemic stationary distribution which results in the stochastic persistence of the infectious disease. The most interesting finding is that large environmental noise can suppress the outbreak of the disease.

  6. Fractional virus epidemic model on financial networks

    Directory of Open Access Journals (Sweden)

    Balci Mehmet Ali

    2016-01-01

    Full Text Available In this study, we present an epidemic model that characterizes the behavior of a financial network of globally operating stock markets. Since the long time series have a global memory effect, we represent our model by using the fractional calculus. This model operates on a network, where vertices are the stock markets and edges are constructed by the correlation distances. Thereafter, we find an analytical solution to commensurate system and use the well-known differential transform method to obtain the solution of incommensurate system of fractional differential equations. Our findings are confirmed and complemented by the data set of the relevant stock markets between 2006 and 2016. Rather than the hypothetical values, we use the Hurst Exponent of each time series to approximate the fraction size and graph theoretical concepts to obtain the variables.

  7. Epidemics scenarios in the "Romantic network".

    Directory of Open Access Journals (Sweden)

    Alexsandro M Carvalho

    Full Text Available The networks of sexual contacts together with temporal interactions play key roles in the spread of sexually transmitted infections. Unfortunately, data for this kind of network is scarce. One of the few exceptions, the "Romantic network", is a complete structure of a real sexual network in a high school. Based on many network measurements the authors of the work have concluded that it does not correspond to any other model network. Regarding the temporal structure, several studies indicate that relationship timing can have an effect on the diffusion throughout networks, as relationship order determines transmission routes. The aim is to check if the particular structure, static and dynamic, of the Romantic network is determinant for the propagation of an STI. We performed simulations in two scenarios: the static network where all contacts are available and the dynamic case where contacts evolve over time. In the static case, we compared the epidemic results in the Romantic network with some paradigmatic topologies. In the dynamic scenario, we considered the dynamics of formation of pairs in the Romantic network and we studied the propagation of the diseases. Our results suggest that although this real network cannot be labeled as a Watts-Strogatz network, it is, in regard to the propagation of an STI, very similar to a high disorder network. Additionally, we found that: the effect that any individual contacting an externally infected subject is to make the network closer to a fully connected one, the higher the contact degree of patient zero the faster the spread of the outbreaks, and the epidemic impact is proportional to the numbers of contacts per unit time. Finally, our simulations confirm that relationship timing severely reduced the final outbreak size, and also, show a clear correlation between the average degree and the outbreak size over time.

  8. Information content of household-stratified epidemics

    Directory of Open Access Journals (Sweden)

    T.M. Kinyanjui

    2016-09-01

    Full Text Available Household structure is a key driver of many infectious diseases, as well as a natural target for interventions such as vaccination programs. Many theoretical and conceptual advances on household-stratified epidemic models are relatively recent, but have successfully managed to increase the applicability of such models to practical problems. To be of maximum realism and hence benefit, they require parameterisation from epidemiological data, and while household-stratified final size data has been the traditional source, increasingly time-series infection data from households are becoming available. This paper is concerned with the design of studies aimed at collecting time-series epidemic data in order to maximize the amount of information available to calibrate household models. A design decision involves a trade-off between the number of households to enrol and the sampling frequency. Two commonly used epidemiological study designs are considered: cross-sectional, where different households are sampled at every time point, and cohort, where the same households are followed over the course of the study period. The search for an optimal design uses Bayesian computationally intensive methods to explore the joint parameter-design space combined with the Shannon entropy of the posteriors to estimate the amount of information in each design. For the cross-sectional design, the amount of information increases with the sampling intensity, i.e., the designs with the highest number of time points have the most information. On the other hand, the cohort design often exhibits a trade-off between the number of households sampled and the intensity of follow-up. Our results broadly support the choices made in existing epidemiological data collection studies. Prospective problem-specific use of our computational methods can bring significant benefits in guiding future study designs.

  9. Information content of household-stratified epidemics.

    Science.gov (United States)

    Kinyanjui, T M; Pellis, L; House, T

    2016-09-01

    Household structure is a key driver of many infectious diseases, as well as a natural target for interventions such as vaccination programs. Many theoretical and conceptual advances on household-stratified epidemic models are relatively recent, but have successfully managed to increase the applicability of such models to practical problems. To be of maximum realism and hence benefit, they require parameterisation from epidemiological data, and while household-stratified final size data has been the traditional source, increasingly time-series infection data from households are becoming available. This paper is concerned with the design of studies aimed at collecting time-series epidemic data in order to maximize the amount of information available to calibrate household models. A design decision involves a trade-off between the number of households to enrol and the sampling frequency. Two commonly used epidemiological study designs are considered: cross-sectional, where different households are sampled at every time point, and cohort, where the same households are followed over the course of the study period. The search for an optimal design uses Bayesian computationally intensive methods to explore the joint parameter-design space combined with the Shannon entropy of the posteriors to estimate the amount of information in each design. For the cross-sectional design, the amount of information increases with the sampling intensity, i.e., the designs with the highest number of time points have the most information. On the other hand, the cohort design often exhibits a trade-off between the number of households sampled and the intensity of follow-up. Our results broadly support the choices made in existing epidemiological data collection studies. Prospective problem-specific use of our computational methods can bring significant benefits in guiding future study designs. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Heroin epidemics, treatment and ODE modelling.

    Science.gov (United States)

    White, Emma; Comiskey, Catherine

    2007-07-01

    The UN [United Nations Office on Drugs and Crime (UNODC): World Drug Report, 2005, vol. 1: Analysis. UNODC, 2005.], EU [European Monitoring Centre for Drugs and Drug Addiction (EMCDDA): Annual Report, 2005.http://annualreport.emcdda.eu.int/en/home-en.html.] and WHO [World Health Organisation (WHO): Biregional Strategy for Harm Reduction, 2005-2009. HIV and Injecting Drug Use. WHO, 2005.] have consistently highlighted in recent years the ongoing and persistent nature of opiate and particularly heroin use on a global scale. While this is a global phenomenon, authors have emphasised the significant impact such an epidemic has on individual lives and on society. National prevalence studies have indicated the scale of the problem, but the drug-using career, typically consisting of initiation, habitual use, a treatment-relapse cycle and eventual recovery, is not well understood. This paper presents one of the first ODE models of opiate addiction, based on the principles of mathematical epidemiology. The aim of this model is to identify parameters of interest for further study, with a view to informing and assisting policy-makers in targeting prevention and treatment resources for maximum effectiveness. An epidemic threshold value, R(0), is proposed for the drug-using career. Sensitivity analysis is performed on R(0) and it is then used to examine the stability of the system. A condition under which a backward bifurcation may exist is found, as are conditions that permit the existence of one or more endemic equilibria. A key result arising from this model is that prevention is indeed better than cure.

  11. Clinical Profile of Suspected and Confirmed H1N1 Influenza Infection in Patients admitted at a Tertiary Care Teaching Hospital

    Directory of Open Access Journals (Sweden)

    Basavaraju Jayadeva

    2015-11-01

    Full Text Available Introduction: This study aimed to evaluate the clinical profile and outcomes of adult patients screened and diagnosed with H1N1 influenza infection at a tertiary care hospital in India. Materials and Methods: This retrospective  study was conducted on all adult patients suspected of H1N1 influenza admitted at a teaching hospital during the epidemic period of January-March 2015. Patients were screened and classified into three categories of A, B, and C based on international guidelines. Home confinement was recommended for patients in category A, and subjects in category B received treatment with Oseltamivir capsules. In addition, patients in category C received inpatient treatment with oseltamivir capsules. Results: In total, 695 patients were screened for H1N1 influenza infection during the epidemic, out of whom 380 patients (54.6% were in category A, 264 (37.9% were in category B, and 51 (7.3% were in category C. Throat swabs were collected and examined for 192 ( 27.6% patients, and 59 ( 8.4% cases were positive for H1N1 infection. Conclusion: According to the results of this study, close vigilance over the symptoms of patients infected with H1N1 influenza is more important than treatment and screening of suspicious cases during the epidemics of this infection. This is a retrospective cross sectional study. Hence, there were no comparative controls. The limitation of this study is,  thus the lack of control.

  12. Differential Diagnosis of Children with Suspected Childhood Apraxia of Speech

    Science.gov (United States)

    Murray, Elizabeth; McCabe, Patricia; Heard, Robert; Ballard, Kirrie J.

    2015-01-01

    Purpose: The gold standard for diagnosing childhood apraxia of speech (CAS) is expert judgment of perceptual features. The aim of this study was to identify a set of objective measures that differentiate CAS from other speech disorders. Method: Seventy-two children (4-12 years of age) diagnosed with suspected CAS by community speech-language…

  13. Use of budesonide Turbuhaler in young children suspected of asthma

    DEFF Research Database (Denmark)

    Bisgaard, H; Pedersen, S; Nikander, K

    1994-01-01

    The question addressed in this study was the ability of young children to use a dry-powder inhaler, Turbuhaler. One hundred and sixty five children suspected of asthma, equally distributed in one year age-groups from 6 months to 8 yrs, inhaled from a Pulmicort Turbuhaler, 200 micrograms budesonide...

  14. Spatial epidemiology of suspected clinical leptospirosis in Sri Lanka.

    Science.gov (United States)

    Robertson, C; Nelson, T A; Stephen, C

    2012-04-01

    Leptospirosis is one of the most widespread zoonoses in the world. A large outbreak of suspected human leptospirosis began in Sri Lanka during 2008. This study investigated spatial variables associated with suspected leptospirosis risk during endemic and outbreak periods. Data were obtained for monthly numbers of reported cases of suspected clinical leptospirosis for 2005-2009 for all of Sri Lanka. Space-time scan statistics were combined with regression modelling to test associations during endemic and outbreak periods. The cross-correlation function was used to test association between rainfall and leptospirosis at four locations. During the endemic period (2005-2007), leptospirosis risk was positively associated with shorter average distance to rivers and with higher percentage of agriculture made up of farms <0·20 hectares. Temporal correlation analysis of suspected leptospirosis cases and rainfall revealed a 2-month lag in rainfall-case association during the baseline period. Outbreak locations in 2008 were characterized by shorter distance to rivers and higher population density. The analysis suggests the possibility of household transmission in densely populated semi-urban villages as a defining characteristic of the outbreak. The role of rainfall in the outbreak remains to be investigated, although analysis here suggests a more complex relationship than simple correlation.

  15. PMS2 Involvement in Patients Suspected of Lynch Syndrome

    NARCIS (Netherlands)

    Niessen, Renee C.; Kleibeuker, Jan H.; Westers, Helga; Jager, Paul O. J.; Rozeveld, Dennie; Bos, Krista K.; Boersma-van Ek, Wytske; Hollema, Harry; Sijmons, Rolf H.; Hofstra, Robert M. W.

    It is well-established that germline mutations in the mismatch repair genes MLH1, MSH2, and MSH6 cause Lynch syndrome. However, mutations in these three genes do not account for all Lynch syndrome (suspected) families. Recently, it was shown that germline mutations in another mismatch repair gene,

  16. Correlates and Suspected Causes of Obesity in Children

    Science.gov (United States)

    Crothers, Laura M.; Kehle, Thomas J.; Bray, Melissa A.; Theodore, Lea A.

    2009-01-01

    The correlates and suspected causes of the intractable condition obesity are complex and involve environmental and heritable, psychological and physical variables. Overall, the factors associated with and possible causes of it are not clearly understood. Although there exists some ambiguity in the research regarding the degree of happiness in…

  17. 48 CFR 3.303 - Reporting suspected antitrust violations.

    Science.gov (United States)

    2010-10-01

    ... suspect. Paragraph (c) below identifies behavior patterns that are often associated with antitrust... offers; (2) A sudden change from competitive bidding to identical bidding; (3) Simultaneous price... turn in sequence as low bidder, or so that certain competitors bid low only on some sizes of contracts...

  18. Is extended biopsy protocol justified in all patients with suspected ...

    African Journals Online (AJOL)

    Objective: To determine the significance of an extended 10-core transrectal biopsy protocol in different categories of patients with suspected prostate cancer using digital guidance. Materials and Methods: We studied 125 men who were being evaluated for prostate cancer. They all had an extended 10-core digitally guided ...

  19. A suspected case of Addison's disease in cattle.

    Science.gov (United States)

    Lambacher, Bianca; Wittek, Thomas

    2015-09-01

    A 4.75-year old Simmental cow was presented with symptoms of colic and ileus. The clinical signs and blood analysis resulted in the diagnosis of suspected primary hypoadrenocorticism (Addison's disease). Although Addison's disease has been frequently described in other domestic mammals, to our knowledge, this disease has not previously been reported in cattle.

  20. Talking heads : interviewing suspects from a cultural perspective

    NARCIS (Netherlands)

    Beune, K.

    2009-01-01

    Although the literature on the interviewing of suspects has increased over the past decade, research on the use and effectiveness of police strategies and their boundary conditions is very rare. The present dissertation aims to fill this void by identifying behaviors that appeal to and persuade

  1. 48 CFR 903.303 - Reporting suspected antitrust violations.

    Science.gov (United States)

    2010-10-01

    ... as described in FAR 3.301, and antitrust law violations as described in FAR 3.303, evidenced in bids... antitrust violations. 903.303 Section 903.303 Federal Acquisition Regulations System DEPARTMENT OF ENERGY GENERAL IMPROPER BUSINESS PRACTICES AND PERSONAL CONFLICTS OF INTEREST Reports of Suspected Antitrust...

  2. Suspected infection in afebrile patients : Are they septic?

    NARCIS (Netherlands)

    Martins, Fernanda de Souza; Guedes, Gisele Giuliane; Santos, Thiago Martins; de Carvalho-Filho, Marco A

    We prospectively evaluated afebrile patients admitted to an emergency department (ED), with suspected infection and only tachycardia or tachypnea.The white blood cell count (WBC) was obtained, and patients were considered septic if leukocyte count was >12,000 μL-1 or <4000 μL-1 or with >10% of band

  3. Cognitive Linguistic Performances of Multilingual University Students Suspected of Dyslexia

    Science.gov (United States)

    Lindgren, Signe-Anita; Laine, Matti

    2011-01-01

    High-performing adults with compensated dyslexia pose particular challenges to dyslexia diagnostics. We compared the performance of 20 multilingual Finnish university students with suspected dyslexia with 20 age-matched and education-matched controls on an extensive test battery. The battery tapped various aspects of reading, writing, word…

  4. Lineup Composition, Suspect Position, and the Sequential Lineup Advantage

    Science.gov (United States)

    Carlson, Curt A.; Gronlund, Scott D.; Clark, Steven E.

    2008-01-01

    N. M. Steblay, J. Dysart, S. Fulero, and R. C. L. Lindsay (2001) argued that sequential lineups reduce the likelihood of mistaken eyewitness identification. Experiment 1 replicated the design of R. C. L. Lindsay and G. L. Wells (1985), the first study to show the sequential lineup advantage. However, the innocent suspect was chosen at a lower rate…

  5. Pathologically confirmed autoimmune encephalitis in suspected Creutzfeldt-Jakob disease

    NARCIS (Netherlands)

    Maat, P.; de Beukelaar, J.W.; Jansen, C.; Schuur, M.; van Duijn, C.M.; van Coevorden, M.H.; de Graaff, E.; Titulaer, E.; Rozemuller, A.J.M.; Sillevis Smitt, P.

    2015-01-01

    Objective: To determine the clinical features and presence in CSF of antineuronal antibodies in patients with pathologically proven autoimmune encephalitis derived from a cohort of patients with suspected Creutzfeldt-Jakob disease (CJD). Methods: The Dutch Surveillance Centre for Prion Diseases

  6. DNA typing from vaginal smear slides in suspected rape cases

    Directory of Open Access Journals (Sweden)

    Dayse Aparecida da Silva

    Full Text Available In an investigation of suspected rape, proof of sexual assault with penetration is required. In view of this, detailed descriptions of the genitalia, the thighs and pubic region are made within the forensic medical service. In addition, vaginal swabs are taken from the rape victim and some of the biological material collected is then transferred to glass slides. In this report, we describe two rape cases solved using DNA typing from cells recovered from vaginal smear slides. In 1999, two young women informed the Rio de Janeiro Police Department that they had been victims of sexual assaults. A suspect was arrested and the victims identified him as the offender. The suspect maintained that he was innocent. In order to elucidate these crimes, vaginal smear slides were sent to the DNA Diagnostic Laboratory for DNA analysis three months after the crimes, as unique forensic evidence. To get enough epithelial and sperm cells to perform DNA analysis, we used protocols modified from the previously standard protocols used for DNA extraction from biological material fixed on glass slides. The quantity of cells was sufficient to perform human DNA typing using nine short tandem repeat (STR loci. It was 3.3 billion times more probable that it was the examined suspect who had left sperm cells in the victims, rather than any other individual in the population of Rio de Janeiro.

  7. Risk Factors and Bacterial Profile of Suspected Neonatal ...

    African Journals Online (AJOL)

    Neonatal septicaemia is a common cause of morbidity and mortality in developing countries and a major health concern. The aim of this study is to evaluate the bacterial profile, antibiotics susceptibility pattern and associated risk factors of suspected septicaemia in neonates in this locality. Five hundred and forty seven ...

  8. Is extended biopsy protocol justified in all patients with suspected ...

    African Journals Online (AJOL)

    2012-01-03

    Jan 3, 2012 ... Objective: To determine the significance of an extended 10-core transrectal biopsy protocol in different categories of patients with suspected prostate cancer using digital guidance. Materials and Methods: We studied 125 men who were being evaluated for prostate cancer. They all had an extended.

  9. Suspected pulmonary tuberculosis in rural South Africa - Sputum ...

    African Journals Online (AJOL)

    Three (125%) of the 24 patients with a discharge diagnosis other than TB (17 pneumonia, 3 old TB, 2 carcinoma of the lung, 1 bronchiectasis) turned out to have TB within the follow-up period; 2 of those had extrapulmonary TB Conclusion, SI produced a positive smear result in 29% of patients with suspected TB who had ...

  10. Are cutaneous hypersensitivity tests to inhalant allergens a severity marker for vernal keratoconjunctivitis? Os testes de hipersensibilidade cutânea contra alérgenos inalantes são marcadores de gravidade da ceratoconjuntivite vernal?

    Directory of Open Access Journals (Sweden)

    Lauro Augusto de Oliveira

    2007-12-01

    Full Text Available PURPOSE: The purpose of this study was to analyze the cutaneous sensitivity to a variety of allergens in patients with vernal keratoconjunctivitis (VKC and to demonstrate the relation between skin response and clinical aspects of the disease. METHODS: Twenty patients with vernal keratoconjunctivitis were randomly chosen from the External Disease and Cornea Sector. They were clinically evaluated, and a score ranging from 0 to 20 was applied based on signs and symptoms on ophthalmic examination. All subjects underwent a skin prick test against standardized allergens, such as house dust mites D. pteronyssinus, D. farinae, and Blomia tropicalis, as well as allergens from cat, dog, fungi and feather. RESULTS: Seventy-five per cent of patients were positive for at least one of the allergens tested. House dust mites were responsible for the majority of the cases (75%. There was a poor correlation between the clinical score and sensitivity to allergens (r= - 0.119 for fungi; r= - 0.174 for dog; r= - 0.243 for house dust mites; r= - 0.090 for feather. A significant correlation was found only for cat allergen extract (r = - 0.510; p=0.024. CONCLUSIONS: Our study demonstrated poor correlation between cutaneous hypersensitivity tests and clinical findings in patients with vernal keratoconjuntivitis. We concluded that skin response to inhalant allergens is not a useful test to identify clinical severity and chronicity of inflammatory process in this disease.OBJETIVO: Avaliar o papel da sensibilização cutânea a diferentes aeroalérgenos em pacientes com ceratoconjuntivite vernal e a correlação entre esta e os aspectos clínicos da doença. MÉTODOS: Vinte pacientes do setor de doenças externas e córnea foram aleatoriamente convidados para participar deste estudo. Os pacientes foram avaliados e a eles foi atribuído um escore clínico variando de 0 a 20 de acordo com sinais e sintomas presentes no exame oftalmológico. Todos os pacientes foram

  11. Comparison of clinically suspected injuries with injuries detected at whole-body CT in suspected multi-trauma victims

    International Nuclear Information System (INIS)

    Shannon, L.; Peachey, T.; Skipper, N.; Adiotomre, E.; Chopra, A.; Marappan, B.; Kotnis, N.

    2015-01-01

    Aim: To assess the accuracy of the trauma team leader's clinical suspicion of injury in patients who have undergone whole-body computed tomography (WBCT) for suspected polytrauma, and to assess the frequency of unsuspected injuries and specific patterns of injury at WBCT. Materials and methods: Requests for patients who underwent WBCT for suspected polytrauma from April 2011 to March 2014 were reviewed and each body area that was clinically suspected to be injured was recorded. Body areas were divided into the following groups based on anatomical regions covered in each segment of the WBCT examination: head (including facial bones); neck (including cervical spine); chest (including thoracic spine); and abdomen/pelvis (including lumbar spine). The formal radiology report for each study was reviewed and injuries found at CT were grouped into the same body areas. For each patient, the number of clinically suspected injured areas was compared to the number of confirmed injured areas at WBCT. Results: Five hundred and eighty-eight patients were included in the study. Thirty-two percent (186/588) had a normal scan. Ninety-three percent (546/588) had fewer injured body areas at WBCT than suspected. Four percent (27/588) had the equivalent number of injured areas at WBCT as suspected. Three percent (15/588) had more injured areas at WBCT than suspected. Fifty percent (263/527) with clinically suspected chest injuries were confirmed to have chest injuries at WBCT. This was lower for other areas: abdomen/pelvis 31% (165/535); head 29% (155/533); neck 13% (66/513). Four percent of (24/588) patients had unsuspected injuries found at WBCT. Seventy-five percent (18/24) of unsuspected injuries were considered as serious, where failure to treat would have the potential for significant morbidity. Most of these patients had severe injuries to other body areas that were correctly suspected. Of the 165 with abdominal/pelvic region injuries, there were associated injuries in the

  12. Comparison of hyaluronic acid-containing topical eye drops with carbomer-based topical ocular gel as a tear replacement in canine keratoconjunctivitis sicca: A prospective study in twenty five dogs

    Directory of Open Access Journals (Sweden)

    David Williams

    2012-12-01

    Full Text Available The aim of this study was to evaluate the efficacy of a hyaluronic acid containing eye drop in ameliorating ocular surface pathology and discomfort in canine keratoconjunctivitis sicca (KCS. Twenty five dogs with KCS treated with a topical carbomer (CA-based tear replacement gel were moved to treatment with a hyaluronic acid (HA-containing tear replacement eye drop. Dogs were subject to a full ophthalmic examination at the beginning of the study and after two and four weeks of treatment, Schirmer tear tests (STTs were performed at each examination. Conjunctival hyperemia, ocular discharge and ocular irritation were evaluated and scored on a 0-3 semi-quantitative scale. Values were compared before and after 4 weeks of treatment using a paired t-test. Evaluation scores were compared using the Wilcoxon signed rank test. The transfer from CA-based to HA-containing tear replacement significantly decreased the conjunctival hyperemia score from 2.12 ± 0.73 to 1.26 ± 0.59 and ocular discomfort was lowered from 2.11 ± 0.97 to 0.93 ± 0.75. Ocular discharge was reduced from a score of 1.04 ± 0.82 to 0.70 ± 0.53, however, the decrease did not reach statistical significance. Schirmer tear test was increased with statistical significance (p < 0.001 but given that the increase was only from 5.42 ± 3.50 to 6.19 ± 3.86 mm min-1; this was not considered clinically significant. This study demonstrated that HA-containing eye drops used twice daily in dogs with KCS had greater ameliorative effects on ocular surface health and discomfort than did CA-based topical gels used as or more frequently.

  13. Can influenza epidemics be prevented by voluntary vaccination?

    Directory of Open Access Journals (Sweden)

    Raffaele Vardavas

    2007-05-01

    Full Text Available Previous modeling studies have identified the vaccination coverage level necessary for preventing influenza epidemics, but have not shown whether this critical coverage can be reached. Here we use computational modeling to determine, for the first time, whether the critical coverage for influenza can be achieved by voluntary vaccination. We construct a novel individual-level model of human cognition and behavior; individuals are characterized by two biological attributes (memory and adaptability that they use when making vaccination decisions. We couple this model with a population-level model of influenza that includes vaccination dynamics. The coupled models allow individual-level decisions to influence influenza epidemiology and, conversely, influenza epidemiology to influence individual-level decisions. By including the effects of adaptive decision-making within an epidemic model, we can reproduce two essential characteristics of influenza epidemiology: annual variation in epidemic severity and sporadic occurrence of severe epidemics. We suggest that individual-level adaptive decision-making may be an important (previously overlooked causal factor in driving influenza epidemiology. We find that severe epidemics cannot be prevented unless vaccination programs offer incentives. Frequency of severe epidemics could be reduced if programs provide, as an incentive to be vaccinated, several years of free vaccines to individuals who pay for one year of vaccination. Magnitude of epidemic amelioration will be determined by the number of years of free vaccination, an individuals' adaptability in decision-making, and their memory. This type of incentive program could control epidemics if individuals are very adaptable and have long-term memories. However, incentive-based programs that provide free vaccination for families could increase the frequency of severe epidemics. We conclude that incentive-based vaccination programs are necessary to control

  14. Five challenges for stochastic epidemic models involving global transmission

    Directory of Open Access Journals (Sweden)

    Tom Britton

    2015-03-01

    Full Text Available The most basic stochastic epidemic models are those involving global transmission, meaning that infection rates depend only on the type and state of the individuals involved, and not on their location in the population. Simple as they are, there are still several open problems for such models. For example, when will such an epidemic go extinct and with what probability (questions depending on the population being fixed, changing or growing? How can a model be defined explaining the sometimes observed scenario of frequent mid-sized epidemic outbreaks? How can evolution of the infectious agent transmission rates be modelled and fitted to data in a robust way?

  15. Epidemic Spread in Networks Induced by Deactivation Mechanism

    International Nuclear Information System (INIS)

    Yu Xiaoling; Wu Xiao; Zhang Duanming; Li Zhihao; Liang Fang; Wang Xiaoyu

    2008-01-01

    We have studied the topology and epidemic spreading behaviors on the networks in which deactivation mechanism and long-rang connection are coexisted. By means of numerical simulation, we find that the clustering coefficient C and the Pearson correlation coefficient r decrease with increasing long-range connection μ and the topological state of the network changes into that of BA model at the end (when μ = 1). For the Susceptible-Infect-Susceptible model of epidemics, the epidemic threshold can reach maximum value at μ = 0.4 and presents two different variable states around μ = 0.4

  16. Know your epidemic, know your response: targeting HIV in Asia

    DEFF Research Database (Denmark)

    Lazarus, Jeff; Curth, Nadja; Bridge, Jamie

    2010-01-01

    This article provides an overview of the HIV epidemic in Asia, the context within which the epidemic is evolving, and the key actions to address the challenges faced by countries and risk groups. HIV epidemics across Asia are predominantly concentrated among most-at-risk populations. Although...... prevention and treatment services. In order to reach the Millennium Development Goal of halting and reversing the spread of HIV by 2015 and to achieve universal access to HIV treatment, these barriers must be overcome across Asia. High-impact programs must be targeted at those in need, with continuous...

  17. The impact of awareness on epidemic spreading in networks.

    Science.gov (United States)

    Wu, Qingchu; Fu, Xinchu; Small, Michael; Xu, Xin-Jian

    2012-03-01

    We explore the impact of awareness on epidemic spreading through a population represented by a scale-free network. Using a network mean-field approach, a mathematical model for epidemic spreading with awareness reactions is proposed and analyzed. We focus on the role of three forms of awareness including local, global, and contact awareness. By theoretical analysis and simulation, we show that the global awareness cannot decrease the likelihood of an epidemic outbreak while both the local awareness and the contact awareness can. Also, the influence degree of the local awareness on disease dynamics is closely related with the contact awareness.

  18. Inhomogeneity of epidemic spreading with entropy-based infected clusters.

    Science.gov (United States)

    Wen-Jie, Zhou; Xing-Yuan, Wang

    2013-12-01

    Considering the difference in the sizes of the infected clusters in the dynamic complex networks, the normalized entropy based on infected clusters (δ*) is proposed to characterize the inhomogeneity of epidemic spreading. δ* gives information on the variability of the infected clusters in the system. We investigate the variation in the inhomogeneity of the distribution of the epidemic with the absolute velocity v of moving agent, the infection density ρ, and the interaction radius r. By comparing δ* in the dynamic networks with δH* in homogeneous mode, the simulation experiments show that the inhomogeneity of epidemic spreading becomes smaller with the increase of v, ρ, r.

  19. The psychiatric epidemic in the American workplace.

    Science.gov (United States)

    Brodsky, C M

    1988-01-01

    make renouncement tantamount to betrayal. The mass psychogenic illness or psychiatric epidemic that occurs in the workplace offers an opportunity not only to study the elements of a biopsychosocial system, but also offers opportunities for medical anthropological studies that relate the causes and courses of specific episodes of MPI to the cultures of the individuals who develop symptoms and the cultures of the area in which the epidemic occurs.

  20. A field investigation into a suspected outbreak of pyrrolizidine alkaloid toxicosis in horses in western Queensland.

    Science.gov (United States)

    Robinson, B; Gummow, B

    2015-03-01

    A disease outbreak investigation was conducted in western Queensland to investigate a rare suspected outbreak of pyrrolizidine alkaloid (PA) toxicosis in horses. Thirty five of 132 horses depastured on five properties on the Mitchell grass plains of western Queensland died in the first six months of 2010. Clinical-pathological findings were consistent with PA toxicosis. A local variety of Crotalaria medicaginea was the only hepatotoxic plant found growing on affected properties. Pathology reports and departure and arrival dates of two brood mares provided evidence of a pre wet season exposure period. All five affected properties experienced a very dry spring and early summer preceded by a large summer wet season. The outbreak was characterised as a point epidemic with a sudden peak of deaths in March followed by mortalities steadily declining until the end of June. The estimated morbidity (serum IGG>50IU/L) rate was 76%. Average crude mortality was 27% but higher in young horses (67%) and brood mares (44%). Logistic regression analysis showed that young horses and brood mares and those grazing denuded pastures in December were most strongly associated with dying whereas those fed hay and/or grain based supplements were less likely to die. This is the first detailed study of an outbreak of PA toxicosis in central western Queensland and the first to provide evidence that environmental determinants were associated with mortality, that the critical exposure period was towards the end of the dry season, that supplementary feeding is protective and that denuded pastures and the horses physiological protein requirement are risk factors. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Methods for Characterisation of unknown Suspect Radioactive Samples

    International Nuclear Information System (INIS)

    Sahagia, M.; Grigorescu, E.L.; Luca, A.; Razdolescu, A.C.; Ivan, C.

    2001-01-01

    Full text: The paper presents various identification and measurement methods, used for the expertise of a wide variety of suspect radioactive materials, whose circulation was not legally stated. The main types of examined samples were: radioactive sources, illegally trafficked; suspect radioactive materials or radioactively contaminated devices; uranium tablets; fire detectors containing 241 Am sources; osmium samples containing radioactive 185 Os or enriched 187 Os. The types of analyses and determination methods were as follows: the chemical composition was determined by using identification reagents or by neutron activation analysis; the radionuclide composition was determined by using gamma-ray spectrometry; the activity and particle emission rates were determined by using calibrated radiometric equipment; the absorbed dose rate at the wall of all types of containers and samples was determined by using calibrated dose ratemeters. The radiation exposure risk for population, due to these radioactive materials, was evaluated for every case. (author)

  2. Cholescintigraphy and ultrasonography in patients suspected of having acute cholecystitis

    DEFF Research Database (Denmark)

    Lauritsen, K B; Sommer, W; Hahn, L

    1988-01-01

    The diagnostic power of combined cholescintigraphy and ultrasonography was tested in 67 patients suspected of having acute cholecystitis; of these, 42 (63%) had acute cholecystitis. The predictive value of a positive scintigraphy (PVpos) was 95% and that of a negative (PVneg) was 91% (n = 67......). The PVpos and PVneg of ultrasonography were 89% and 75%, respectively (n = 54), and these values did not achieve statistical significance when compared with those for scintigraphy. Inconclusive tests were 10% and 11%, respectively, but in no patient were both scintigraphy and ultrasonography inconclusive...... that in patients suspected of having acute cholecystitis cholescintigraphy should be the first diagnostic procedure performed. If the scintigraphy is positive, additional ultrasonographic detection of gallstones makes the diagnosis almost certain. If one diagnostic modality is inconclusive, the other makes a fair...

  3. Interdisciplinary action of nurses to children with suspected sexual abuse

    Directory of Open Access Journals (Sweden)

    Lia Leão Ciuffo

    2014-04-01

    Full Text Available Objective. Understanding the role of nurses as members of interdisciplinary teams in the care of children with suspected sexual abuse. Methodology. This is a qualitative research based on the sociological phenomenology of Alfred Schutz. In 2008 were interviewed eleven nurses who worked in reference institutions for the care of child victims of sexual abuse in Rio de Janeiro. Results. The category called 'Interacting with other professionals in child care' emerged from the analysis of performance of professionals. The intersubjective relations between the nurses and the interdisciplinary team will enable to understand the intent of care from the perspective of social, emotional and psychological needs of children and their families. Conclusion. Interdisciplinarity favored the development of actions based on acceptance, listening and agreements on possible solutions in the care of children with suspected sexual abuse.

  4. Incidence of clinically suspected venous thromboembolism in British Indian patients.

    Science.gov (United States)

    Siddiqui, B M; Patel, M S; Rudge, S; Best, A; Mangwani, J

    2018-05-01

    Introduction Venous thromboembolism (VTE) remains a major public health issue around the world. Ethnicity is known to alter the incidence of VTE. To our knowledge, there are no reports in the literature investigating the incidence of VTE in British Indians. The aim of this study was to investigate the rates of symptomatic VTE in British Indian patients in the UK. Methods Patients referred to our institution between January 2011 and August 2013 with clinically suspected VTE were eligible for inclusion in the study. Those not of British Indian or Caucasian ethnicity were excluded. A retrospective review of these two cohorts was conducted. Results Overall, 15,529 cases were referred to our institution for suspected VTE. This included 1,498 individuals of British Indian ethnicity. Of these, 182 (12%) had confirmed VTE episodes. A further 13,159 of the patients with suspected VTE were coded as Caucasian, including 2,412 (16%) who had confirmed VTE events. VTE rates were a third lower in British Indians with clinically suspected VTE than in the equivalent Caucasian group. The British Indian cohort presented with VTE at a much earlier age than Caucasians (mean 57.0 vs 68.0 years). Conclusions This study suggests that British Indian patients have a lower incidence of VTE and are more likely to present at an earlier age than Caucasians. There was no significant difference in VTE type (deep vein thrombosis vs pulmonary embolism) among the ethnic groups. Clinicians should be aware of variations within ethnicities but should continue to adhere to existing VTE prevention guidance.

  5. Spinal cord magnetic resonance imaging in suspected multiple sclerosis

    International Nuclear Information System (INIS)

    Lycklama a Nijeholt, G.J.; Bergers, E.; Castelijns, J.A.; Barkhof, F.; Uitdehaag, B.M.J.; Polman, C.H.

    2000-01-01

    We examined the value of spinal cord magnetic resonance imaging (MRI) in the diagnostic work-up of multiple sclerosis (MS). Forty patients suspected of having MS were examined within 24 months after the start of symptoms. Disability was assessed, and symptoms were categorized as either brain or spinal cord. Work-up further included cerebrospinal fluid analysis and standard proton-density, T2-, and T1-weighted gadolinium-enhanced brain and spinal cord MRI. Patients were categorized as either clinically definite MS (n = 13), laboratory-supported definite MS (n = 14), or clinically probable MS (n = 4); four patients had clinically probable MS, and in nine MS was suspected. Spinal cord abnormalities were found in 35 of 40 patients (87.5 %), consisting of focal lesions in 31, only diffuse abnormalities in two, and both in two. Asymptomatic spinal cord lesions occurred in six patients. All patients with diffuse spinal cord abnormality had clear spinal cord symptoms and a primary progressive disease course. In clinically definite MS, the inclusion of spinal imaging increased the sensitivity of MRI to 100 %. Seven patients without a definite diagnosis had clinically isolated syndromes involving the spinal cord. Brain MRI was inconclusive, while all had focal spinal cord lesions which explained symptoms and ruled out other causes. Two other patients had atypical brain abnormalities suggesting ischemic/vascular disease. No spinal cord abnormalities were found, and during follow-up MS was ruled out. Spinal cord abnormalities are common in suspected MS, and may occur asymptomatic. Although diagnostic classification is seldom changed, spinal cord imaging increases diagnostic sensitivity of MRI in patients with suspected MS. In addition, patients with primary progressive MS may possibly be earlier diagnosed. Finally, differentiation with atypical lesions may be improved. (orig.)

  6. Interviewing strategically to elicit admissions from guilty suspects

    OpenAIRE

    Tekin, Serra; Granhag, Pär Anders; Strömwall, Leif; Giolla, Erik Mac; Vrij, Aldert; Hartwig, Maria

    2015-01-01

    In this article we introduce a novel interviewing tactic to elicit admissions from guilty suspects. By influencing the suspects’ perception of the amount of evidence the interviewer holds against them, we aimed to shift the suspects’ counterinterrogation strategies from less to more forthcoming. The proposed tactic (SUE-Confrontation) is a development of the Strategic Use of Evidence (SUE) framework and aims to affect the suspects’ perception by confronting them with statement-evidence incons...

  7. Creating fair lineups for suspects with distinctive features

    OpenAIRE

    Zarkadi, Theodora; Wade, Kimberley A.; Stewart, Neil

    2009-01-01

    In their descriptions, eyewitnesses often refer to a culprit's distinctive facial features. However, in a police lineup, selecting the only member with the described distinctive feature is unfair to the suspect and provides the police with little further information. For fair and informative lineups, the distinctive feature should be either replicated across foils or concealed on the target. In the present experiments, replication produced more correct identifications in target-present lineup...

  8. Percutaneous cholecystocentesis in cats with suspected hepatobiliary disease.

    Science.gov (United States)

    Byfield, Victoria L; Callahan Clark, Julie E; Turek, Bradley J; Bradley, Charles W; Rondeau, Mark P

    2017-12-01

    Objectives The objective was to evaluate the safety and diagnostic utility of percutaneous ultrasound-guided cholecystocentesis (PUC) in cats with suspected hepatobiliary disease. Methods Medical records of 83 cats with suspected hepatobiliary disease that underwent PUC were retrospectively reviewed. Results At the time of PUC, at least one additional procedure was performed in 79/83 cats, including hepatic aspiration and/or biopsy (n = 75) and splenic aspiration (n = 18). Complications were noted in 14/83 cases, including increased abdominal fluid (n = 11), needle-tip occlusion (n = 1), failed first attempt to penetrate the gall bladder wall (n = 1) and pneumoperitoneum (n = 1). There were no reports of gall bladder rupture, bile peritonitis or hypotension necessitating treatment with vasopressor medication. Blood products were administered to 7/83 (8%) cats. Seventy-two cats (87%) survived to discharge. Of the cats that were euthanized (9/83) or died (2/83), none were reported as a definitive consequence of PUC. Bacteria were identified cytologically in 10/71 samples (14%); all 10 had a positive aerobic bacterial culture. Bile culture was positive in 11/80 samples (14%). Of the cases with a positive bile culture, cytological description of bacteria corresponded to the organism cultured in fewer than 50% of cases. The most common cytologic diagnosis was hepatic lipidosis (49/66). The most common histopathologic diagnosis was cholangitis (10/21). Conclusions and relevance PUC was safe in this group of cats with suspected hepatobiliary disease. Complications were likely associated with ancillary procedures performed at the time of PUC. Bile analysis yielded an abnormal result in nearly one-third of cats with suspected hepatobiliary disease. Complete agreement between bile cytology and culture was lacking. Further evaluation of the correlation between bile cytology and bile culture is warranted.

  9. MRI for clinically suspected pediatric appendicitis: an implemented program

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Michael M.; Gustas, Cristy N.; Choudhary, Arabinda K.; Methratta, Sosamma T.; Hulse, Michael A.; Eggli, Kathleen D.; Boal, Danielle K.B. [Penn State Milton S. Hershey Medical Center, Department of Radiology, Mail Code H066, 500 University Drive, P.O. Box 850, Hershey, PA (United States); Geeting, Glenn [Penn State Milton S. Hershey Medical Center, Department of Emergency Medicine, Hershey, PA (United States)

    2012-09-15

    Emergent MRI is now a viable alternative to CT for evaluating appendicitis while avoiding the detrimental effects of ionizing radiation. However, primary employment of MRI in the setting of clinically suspected pediatric appendicitis has remained significantly underutilized. To describe our institution's development and the results of a fully implemented clinical program using MRI as the primary imaging evaluation for children with suspected appendicitis. A four-sequence MRI protocol consisting of coronal and axial single-shot turbo spin-echo (SS-TSE) T2, coronal spectral adiabatic inversion recovery (SPAIR), and axial SS-TSE T2 with fat saturation was performed on 208 children, ages 3 to 17 years, with clinically suspected appendicitis. No intravenous or oral contrast material was administered. No sedation was administered. Data collection includes two separate areas: time parameter analysis and MRI diagnostic results. Diagnostic accuracy of MRI for pediatric appendicitis indicated a sensitivity of 97.6% (CI: 87.1-99.9%), specificity 97.0% (CI: 93.2-99.0%), positive predictive value 88.9% (CI: 76.0-96.3%), and negative predictive value 99.4% (CI: 96.6-99.9%). Time parameter analysis indicated clinical feasibility, with time requested to first sequence obtained mean of 78.7 +/- 52.5 min, median 65 min; first-to-last sequence time stamp mean 14.2 +/- 8.8 min, median 12 min; last sequence to report mean 57.4 +/- 35.2 min, median 46 min. Mean age was 11.2 +/- 3.6 years old. Girls represented 57% of patients. MRI is an effective and efficient method of imaging children with clinically suspected appendicitis. Using an expedited four-sequence protocol, sensitivity and specificity are comparable to CT while avoiding the detrimental effects of ionizing radiation. (orig.)

  10. MRI for clinically suspected pediatric appendicitis: case interpretation

    International Nuclear Information System (INIS)

    Moore, Michael M.; Brian, James M.; Methratta, Sosamma T.; Hulse, Michael A.; Choudhary, Arabinda K.; Eggli, Kathleen D.; Boal, Danielle K.B.

    2014-01-01

    As utilization of MRI for clinically suspected pediatric appendicitis becomes more common, there will be increased focus on case interpretation. The purpose of this pictorial essay is to share our institution's case interpretation experience. MRI findings of appendicitis include appendicoliths, tip appendicitis, intraluminal fluid-debris level, pitfalls of size measurements, and complications including abscesses. The normal appendix and inguinal appendix are also discussed. (orig.)

  11. MRI for clinically suspected pediatric appendicitis: case interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Michael M.; Brian, James M.; Methratta, Sosamma T.; Hulse, Michael A.; Choudhary, Arabinda K.; Eggli, Kathleen D.; Boal, Danielle K.B. [Penn State Milton S. Hershey Medical Center, Division of Pediatric Radiology, Department of Radiology, Hershey, PA (United States)

    2014-05-15

    As utilization of MRI for clinically suspected pediatric appendicitis becomes more common, there will be increased focus on case interpretation. The purpose of this pictorial essay is to share our institution's case interpretation experience. MRI findings of appendicitis include appendicoliths, tip appendicitis, intraluminal fluid-debris level, pitfalls of size measurements, and complications including abscesses. The normal appendix and inguinal appendix are also discussed. (orig.)

  12. Current Zika virus epidemiology and recent epidemics.

    Science.gov (United States)

    Ioos, S; Mallet, H-P; Leparc Goffart, I; Gauthier, V; Cardoso, T; Herida, M

    2014-07-01

    The Zika virus (ZIKV) is a mosquito-borne flavivirus (Aedes), similar to other arboviruses, first identified in Uganda in 1947. Few human cases were reported until 2007, when a Zika outbreak occurred in Yap, Micronesia, even though ZIKV activity had been reported in Africa and in Asia through virological surveillance and entomological studies. French Polynesia has recorded a large outbreak since October 2013. A great number of cases and some with neurological and autoimmune complications have been reported in a context of concurrent circulation of dengue viruses. The clinical presentation is a "dengue-like syndrome". Until the epidemic in French Polynesia, no severe ZIKV disease had been described so far. The diagnosis is confirmed by viral genome detection by genomic amplification (RT- PCR) and viral isolation. These two large outbreaks occurred in a previously unaffected area in less than a decade. They should raise awareness as to the potential for ZIKV to spread especially since this emergent disease is not well known and that some questions remain on potential reservoirs and transmission modes as well as on clinical presentations and complications. ZIKV has the potential to spread to new areas where the Aedes mosquito vector is present and could be a risk for Southern Europe. Strategies for the prevention and control of ZIKV disease should include the use of insect repellent and mosquito vector eradication. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  13. Diffusive epidemic process: theory and simulation

    International Nuclear Information System (INIS)

    Maia, Daniel Souza; Dickman, Ronald

    2007-01-01

    We study the continuous absorbing-state phase transition in the one-dimensional diffusive epidemic process via mean-field theory and Monte Carlo simulation. In this model, particles of two species (A and B) hop on a lattice and undergo reactions B → A and A+B → 2B; the total particle number is conserved. We formulate the model as a continuous-time Markov process described by a master equation. A phase transition between the (absorbing) B-free state and an active state is observed as the parameters (reaction and diffusion rates, and total particle density) are varied. Mean-field theory reveals a surprising, nonmonotonic dependence of the critical recovery rate on the diffusion rate of B particles. A computational realization of the process that is faithful to the transition rates defining the model is devised, allowing for direct comparison with theory. Using the quasi-stationary simulation method we determine the order parameter and the survival time in systems of up to 4000 sites. Due to strong finite-size effects, the results converge only for large system sizes. We find no evidence for a discontinuous transition. Our results are consistent with the existence of three distinct universality classes, depending on whether A particles diffusive more rapidly, less rapidly or at the same rate as B particles. We also perform quasi-stationary simulations of the triplet creation model, which yield results consistent with a discontinuous transition at high diffusion rates

  14. Spatially explicit modelling of cholera epidemics

    Science.gov (United States)

    Finger, F.; Bertuzzo, E.; Mari, L.; Knox, A. C.; Gatto, M.; Rinaldo, A.

    2013-12-01

    Epidemiological models can provide crucial understanding about the dynamics of infectious diseases. Possible applications range from real-time forecasting and allocation of health care resources to testing alternative intervention mechanisms such as vaccines, antibiotics or the improvement of sanitary conditions. We apply a spatially explicit model to the cholera epidemic that struck Haiti in October 2010 and is still ongoing. The dynamics of susceptibles as well as symptomatic and asymptomatic infectives are modelled at the scale of local human communities. Dissemination of Vibrio cholerae through hydrological transport and human mobility along the road network is explicitly taken into account, as well as the effect of rainfall as a driver of increasing disease incidence. The model is calibrated using a dataset of reported cholera cases. We further model the long term impact of several types of interventions on the disease dynamics by varying parameters appropriately. Key epidemiological mechanisms and parameters which affect the efficiency of treatments such as antibiotics are identified. Our results lead to conclusions about the influence of different intervention strategies on the overall epidemiological dynamics.

  15. Human enterovirus 71 epidemics: what's next?

    Science.gov (United States)

    Yip, Cyril C. Y.; Lau, Susanna K. P.; Woo, Patrick C. Y.; Yuen, Kwok-Yung

    2013-01-01

    Human enterovirus 71 (EV71) epidemics have affected various countries in the past 40 years. EV71 commonly causes hand, foot and mouth disease (HFMD) in children, but can result in neurological and cardiorespiratory complications in severe cases. Genotypic changes of EV71 have been observed in different places over time, with the emergence of novel genotypes or subgenotypes giving rise to serious outbreaks. Since the late 1990s, intra- and inter-typic recombination events in EV71 have been increasingly reported in the Asia-Pacific region. In particular, ‘double-recombinant’ EV71 strains belonging to a novel genotype D have been predominant in mainland China and Hong Kong over the last decade, though co-circulating with a minority of other EV71 subgenotypes and coxsackie A viruses. Continuous surveillance and genome studies are important to detect potential novel mutants or recombinants in the near future. Rapid and sensitive molecular detection of EV71 is of paramount importance in anticipating and combating EV71 outbreaks. PMID:24119538

  16. The economics of cardiac biomarker testing in suspected myocardial infarction.

    Science.gov (United States)

    Goodacre, Steve; Thokala, Praveen

    2015-03-01

    Suspected myocardial infarction (MI) is a common reason for emergency hospital attendance and admission. Cardiac biomarker measurement is an essential element of diagnostic assessment of suspected MI. Although the cost of a routinely available biomarker may be small, the large patient population and consequences in terms of hospital admission and investigation mean that the economic impact of cardiac biomarker testing is substantial. Economic evaluation involves comparing the estimated costs and effectiveness (outcomes) of two or more interventions or care alternatives. This process creates some difficulties with respect to cardiac biomarkers. Estimating the effectiveness of cardiac biomarkers involves identifying how they help to improve health and how we can measure this improvement. Comparison to an appropriate alternative is also problematic. New biomarkers may be promoted on the basis of reducing hospital admission or length of stay, but hospital admission for low risk patients may incur significant costs while providing very little benefit, making it an inappropriate comparator. Finally, economic evaluation may conclude that a more sensitive biomarker strategy is more effective but, by detecting and treating more cases, is also more expensive. In these circumstances it is unclear whether we should use the more effective or the cheaper option. This article provides an introduction to health economics and addresses the specific issues relevant to cardiac biomarkers. It describes the key concepts relevant to economic evaluation of cardiac biomarkers in suspected MI and highlights key areas of uncertainty and controversy. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  17. Does this adult patient with suspected bacteremia require blood cultures?

    Science.gov (United States)

    Coburn, Bryan; Morris, Andrew M; Tomlinson, George; Detsky, Allan S

    2012-08-01

    Clinicians order blood cultures liberally among patients in whom bacteremia is suspected, though a small proportion of blood cultures yield true-positive results. Ordering blood cultures inappropriately may be both wasteful and harmful. To review the accuracy of easily obtained clinical and laboratory findings to inform the decision to obtain blood cultures in suspected bacteremia. A MEDLINE and EMBASE search (inception to April 2012) yielded 35 studies that met inclusion criteria for evaluating the accuracy of clinical variables for bacteremia in adult immunocompetent patients, representing 4566 bacteremia and 25,946 negative blood culture episodes. Data were extracted to determine the prevalence and likelihood ratios (LRs) of findings for bacteremia. The pretest probability of bacteremia varies depending on the clinical context, from low (eg, cellulitis: 2%) to high (eg, septic shock: 69%). Elevated temperatures alone do not accurately predict bacteremia (for ≥38°C [>100.3°F], LR, 1.9 [95% CI, 1.4-2.4]; for ≥38.5°C [>101.2°F], LR, 1.4 [95% CI, 1.1-2.0]), nor does isolated leukocytosis (LR, cultures should not be ordered for adult patients with isolated fever or leukocytosis without considering the pretest probability. SIRS and the decision rule may be helpful in identifying patients who do not need blood cultures. These conclusions do not apply to immunocompromised patients or when endocarditis is suspected.

  18. Autism spectrum disorder symptoms in juvenile suspects of sex offenses.

    Science.gov (United States)

    't Hart-Kerkhoffs, Lisette A; Jansen, Lucres M; Doreleijers, Theo A; Vermeiren, Robert; Minderaa, Ruud B; Hartman, Catharina A

    2009-02-01

    To investigate autism spectrum disorder (ASD) symptoms in juvenile suspects of sex offenses. A group of 175 juvenile suspected sex offenders (all males, mean +/- SD age = 14.9 +/- 1.4 years) was compared with a matched healthy control group (N = 500, mean +/- SD age = 14.0 +/- 1.4 years) and a group of children with DSM-IV-diagnosed ASD (N = 114, mean +/- SD age = 14.2 +/- 1.9 years) with respect to autistic symptoms as measured by means of a standardized questionnaire, the Children's Social Behavior Questionnaire. Furthermore, specific subgroups of sexual offenders, i.e., child molesters, solo peer offenders, and group offenders, were compared with regard to levels of ASD symptoms. The study was conducted from May 2003 to December 2006. Significantly higher levels of ASD symptoms were found in juvenile sex offenders than in healthy controls, while levels were lower than in the ASD group (F = 148.259, p symptoms than group offenders (F = 5.127, p symptoms are higher in juvenile suspects of sex offenses as compared to the healthy population, which argues for considering specific diagnostic assessment in this population, especially in solo offenders and child molesters. Copyright 2009 Physicians Postgraduate Press, Inc.

  19. Police officers' perceptions and experiences with mentally disordered suspects.

    Science.gov (United States)

    Oxburgh, Laura; Gabbert, Fiona; Milne, Rebecca; Cherryman, Julie

    Despite mentally disordered suspects being over-represented within the criminal justice system, there is a dearth of published literature that examines police officers' perceptions when interviewing this vulnerable group. This is concerning given that police officers are increasingly the first point of contact with these individuals. Using a Grounded Theory approach, this study examined 35 police officers' perceptions and experiences when interviewing mentally disordered suspects. Current safeguards, such as Appropriate Adults, and their experiences of any training they received were also explored. A specially designed questionnaire was developed and distributed across six police forces in England and Wales. Nine conceptual categories emerged from the data that highlighted how police officers' level of experience impacted upon their perceptions when dealing with this cohort. As a consequence, a new model grounded within Schema Theory has emerged termed Police Experience Transitional Model. Implications include the treatment and outcome of mentally disordered suspects being heavily dependent on whom they encounter within the criminal justice system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. [Suspected Alzheimer's disease. Selection of outpatients for neuropsychological assessment].

    Science.gov (United States)

    Wolf, S A; Henry, M; Deike, R; Ebert, A D; Wallesch, C-W

    2008-04-01

    Incipient Alzheimer's disease (AD) is frequently suspected by neurologists and psychiatrists, but diagnosis is difficult to establish. The aim of this report was to analyse to what extent suspicion is confirmed by a comprehensive neuropsychological examination intended to distinguish different types of dementia. Descriptive data analysis was used for investigating the differential diagnoses of 47 outpatients with suspected AD referred to a department of neuropsychology by physicians in private practice. Data analysis was based upon the NINCDS-ADRDA diagnostic criteria of AD. Only 38% of the outpatients examined with suspected AD met the NINCDS-ADRDA diagnostic criteria for AD or mixed dementia from a neuropsychological point of view, whereas 22% met criteria for other types of dementia. The remaining patients met criteria for distinct differential diagnoses (23%) or lacked pathological findings in neuropsychological functions (17%). Neuropsychology is an essential part in the differential diagnosis of mild to moderate dementias. It can aid in differential therapeutic considerations concerning the treatment of dementia, for example in selecting appropriate treatments or avoiding expensive but inappropriate ones.

  1. How useful is gastroesophageal reflux scintigraphy in suspected childhood aspiration

    Energy Technology Data Exchange (ETDEWEB)

    Fawcett, H.D.; Adams, J.C.; Hayden, C.K.; Swischuk, L.E.

    1988-05-01

    It has been suggested that gastroesophageal reflux scintigraphy might be useful in assisting one in determining therapy for patients suspected of aspirating or becoming apneic secondary to gastroesophageal reflux. This, however, has not been our experience and in reviewing 23 patients with recurrent pneumonia and/or apnea who had gastroesophageal reflux scintigraphy, we were able to detect aspiration in only one. This was especially significant since 13 (59%) of these patients had demonstrable reflux, and of these, eight were treated successfully for suspected aspiration even though none was demonstrated isotopically. To be sure, the demonstration of pulmonary aspiration with gastroesophageal reflux scintigraphy had little influence on patient selection and response to therapy. For this reason we feel there is little justification in depending on the GRS for the specific purpose of trying to document pulmonary aspiration in infants and children who are refluxing. One of the more serious complications of gastroesophageal (GE) reflux is aspiration leading to recurrent pulmonary infections and/or apnea. However, it always has been difficult to demonstrate actual aspiration into the lungs, and to be sure, barium studies of the upper GI tract seldom reveal this complication. Recently, however, considerable interest has been generated in gastroesophageal scintigraphy (GRS) as a possible means of documenting such aspiration. Rationale for this stems from the fact that suspected patients can be studied over a longer period of time and in addition, delayed and overnight images can be obtained. However, our experience does not support GRS as being an adequate method for demonstrating aspiration.

  2. Thoracic computed tomography in patients with suspected malignant pleural effusions

    International Nuclear Information System (INIS)

    Traill, Zoee C.; Davies, Robert J.O.; Gleeson, Fergus V.

    2001-01-01

    AIM: To assess the role of contrast-enhanced computed tomography (CT) prospectively in patients with suspected malignant pleural effusions. MATERIALS AND METHODS: Forty consecutive patients referred for the investigation of a suspected malignant pleural effusion had contrast-enhanced thoracic CT, thoracoscopy, thoraco-centesis and pleural biopsy, either percutaneously or at thoracoscopy. Final diagnoses were based on histopathological or cytological analysis (n = 30), autopsy findings (n = 3) or clinical follow-up (n = 7). The pleural surfaces were classified at contrast-enhanced CT as normal or abnormal and, if abnormal, as benign or malignant in appearance using previously established CT criteria for malignant pleural thickening by two observers unaware of the pathological diagnosis. RESULTS: Pleural effusions were malignant in 32 patients and benign in eight patients. Pleural surfaces assessed at CT showed features of malignancy in 27 out of 32 patients with a malignant effusion (sensitivity 84%, specificity 100%). Overall, CT appearances indicated the presence of malignancy in 28 of 32 (87%) patients. All eight patients with benign pleural disease were correctly diagnosed by CT. CONCLUSION: Contrast-enhanced CT is of value in patients with suspected malignant pleural effusions. The previously established criteria for malignant pleural thickening of nodularity, irregularity and pleural thickness >1 cm are reliable in the presence of a pleural effusion. Traill, Z.C. et al. (2001)

  3. Topology dependent epidemic spreading velocity in weighted networks

    International Nuclear Information System (INIS)

    Duan, Wei; Qiu, Xiaogang; Quax, Rick; Lees, Michael; Sloot, Peter M A

    2014-01-01

    Many diffusive processes occur on structured networks with weighted links, such as disease spread by airplane transport or information diffusion in social networks or blogs. Understanding the impact of weight-connectivity correlations on epidemic spreading in weighted networks is crucial to support decision-making on disease control and other diffusive processes. However, a real understanding of epidemic spreading velocity in weighted networks is still lacking. Here we conduct a numerical study of the velocity of a Reed–Frost epidemic spreading process in various weighted network topologies as a function of the correlations between edge weights and node degrees. We find that a positive weight-connectivity correlation leads to a faster epidemic spreading compared to an unweighted network. In contrast, we find that both uncorrelated and negatively correlated weight distributions lead to slower spreading processes. In the case of positive weight-connectivity correlations, the acceleration of spreading velocity is weak when the heterogeneity of weight distribution increases. (paper)

  4. Epidemic spreading in time-varying community networks

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Guangming, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [School of Electronic and Information, Guangdong Polytechnic Normal University, Guangzhou 510665 (China); Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Xingyuan, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China)

    2014-06-15

    The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold q{sub c}. The epidemic will survive when q > q{sub c} and die when q < q{sub c}. These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure.

  5. Epidemic spread in bipartite network by considering risk awareness

    Science.gov (United States)

    Han, She; Sun, Mei; Ampimah, Benjamin Chris; Han, Dun

    2018-02-01

    Human awareness plays an important role in the spread of infectious diseases and the control of propagation patterns. Exploring the interplay between human awareness and epidemic spreading is a topic that has been receiving increasing attention. Considering the fact, some well-known diseases only spread between different species we propose a theoretical analysis of the Susceptible-Infected-Susceptible (SIS) epidemic spread from the perspective of bipartite network and risk aversion. Using mean field theory, the epidemic threshold is calculated theoretically. Simulation results are consistent with the proposed analytic model. The results show that, the final infection density is negative linear with the value of individuals' risk awareness. Therefore, the epidemic spread could be effectively suppressed by improving individuals' risk awareness.

  6. The effect of awareness on networked SIS epidemics

    KAUST Repository

    Paarporn, Keith; Eksin, Ceyhun; Weitz, Joshua S.; Shamma, Jeff S.

    2017-01-01

    the epidemic is currently prevalent. An agent's awareness is weighted from three sources of information: the fraction of infected neighbors in their contact network, their social network, and a global broadcast of the fraction of infected nodes in the entire

  7. Stochastic population and epidemic models persistence and extinction

    CERN Document Server

    Allen, Linda J S

    2015-01-01

    This monograph provides a summary of the basic theory of branching processes for single-type and multi-type processes. Classic examples of population and epidemic models illustrate the probability of population or epidemic extinction obtained from the theory of branching processes. The first chapter develops the branching process theory, while in the second chapter two applications to population and epidemic processes of single-type branching process theory are explored. The last two chapters present multi-type branching process applications to epidemic models, and then continuous-time and continuous-state branching processes with applications. In addition, several MATLAB programs for simulating stochastic sample paths  are provided in an Appendix. These notes originated as part of a lecture series on Stochastics in Biological Systems at the Mathematical Biosciences Institute in Ohio, USA. Professor Linda Allen is a Paul Whitfield Horn Professor of Mathematics in the Department of Mathematics and Statistics ...

  8. Drought and Epidemic Typhus, Central Mexico, 1655–1918

    Science.gov (United States)

    Acuna-Soto, Rudofo; Stahle, David W.

    2014-01-01

    Epidemic typhus is an infectious disease caused by the bacterium Rickettsia prowazekii and transmitted by body lice (Pediculus humanus corporis). This disease occurs where conditions are crowded and unsanitary. This disease accompanied war, famine, and poverty for centuries. Historical and proxy climate data indicate that drought was a major factor in the development of typhus epidemics in Mexico during 1655–1918. Evidence was found for 22 large typhus epidemics in central Mexico, and tree-ring chronologies were used to reconstruct moisture levels over central Mexico for the past 500 years. Below-average tree growth, reconstructed drought, and low crop yields occurred during 19 of these 22 typhus epidemics. Historical documents describe how drought created large numbers of environmental refugees that fled the famine-stricken countryside for food relief in towns. These refugees often ended up in improvised shelters in which crowding encouraged conditions necessary for spread of typhus. PMID:24564928

  9. [Hippocrates. Aphorisms and Epidemics III. Two clinical texts].

    Science.gov (United States)

    Frøland, Anders

    2015-01-01

    The two Hippocratic texts, Aphorisms and Epidemics III, have not been translated into Danish previously. The Aphorisms are 412 short, pithy statements, mostly on the prognosis in relation to certain symptoms in the course of the diseases, very often febrile. The Aphorisms begin with the famous words: "Life is short, the Art long, opportunity fleeting, experiment treacherous, judgment difficult." (Transl. W H S Jones [22]). Epidemics III consists of 28 case histories, again mostly of febrile patients, but also of observations on the connection of the seasons with general morbidity and mortality. The author describes an epidemic, which in some respects resembles Thucydides' report on the plague in Athens in 430 BC. It is suggested, that observations as have been recorded in the seven Hippocratic texts on epidemic diseases are the material on which prognostic statements as those collected in the Aphorisms are founded.

  10. 2,500-year Evolution of the Term Epidemic

    Science.gov (United States)

    Martin-Granel, Estelle

    2006-01-01

    The term epidemic (from the Greek epi [on] plus demos [people]), first used by Homer, took its medical meaning when Hippocrates used it as the title of one of his famous treatises. At that time, epidemic was the name given to a collection of clinical syndromes, such as coughs or diarrheas, occurring and propagating in a given period at a given location. Over centuries, the form and meaning of the term have changed. Successive epidemics of plague in the Middle Ages contributed to the definition of an epidemic as the propagation of a single, well-defined disease. The meaning of the term continued to evolve in the 19th-century era of microbiology. Its most recent semantic evolution dates from the last quarter of the 20th century, and this evolution is likely to continue in the future. PMID:16707055

  11. History of the HIV epidemic and response in Swaziland

    African Journals Online (AJOL)

    that self-stigma, multiple concurrent partnerships and short-term relationships, decision on condom use and ... This prevents MSM from seeking health services. To .... 90-90-90: An ambitious treatment target to help end the AIDS epidemic.

  12. Epidemic cholera in Latin America: spread and routes of transmission.

    Science.gov (United States)

    Guthmann, J P

    1995-12-01

    In the most recent epidemic of cholera in Latin America, nearly a million cases were reported and almost 9000 people died between January 1991 and December 1993. The epidemic spread rapidly from country to country, affecting in three years all the countries of Latin America except Uruguay and the Caribbean. Case-control studies carried out in Peru showed a significant association between drinking water and risk of disease. Cholera was associated with the consumption of unwashed fruit and vegetables, with eating food from street vendors and with contaminated crabmeat transported in travellers' luggage. This article documents the spread of the epidemic and its routes of transmission and discusses whether the introduction of the epidemic to Peru and its subsequent spread throughout the continent could have been prevented.

  13. Epidemic spread over networks with agent awareness and social distancing

    KAUST Repository

    Paarporn, Keith; Eksin, Ceyhun; Weitz, Joshua S.; Shamma, Jeff S.

    2016-01-01

    with their neighbors (social distancing) when they believe the epidemic is currently prevalent or resume normal interactions when they believe there is low risk of becoming infected. The information is a weighted combination of three sources: 1) the average states

  14. Context analysis for epidemic control in the Netherlands

    NARCIS (Netherlands)

    Huizer, Y.L.; Kraaij-Dirkzwager, M.M.; Timen, A.; Schuitmaker-Warnaar, T.J.; van Steenbergen, J.E.

    2014-01-01

    When epidemics occur, experts advise the Ministries on effective control measures. There is uncertainty in the translation of epidemiological evidence into effective outbreak management interventions, due to contradicatory problem perspectives, diverse interests and time pressure. Several models

  15. INTRODUCTION The global HIV epidemic continues to expand with ...

    African Journals Online (AJOL)

    maybe potentially dangerous in low resource settings.6. Women infected with ... The HIV epidemic in children parallels that among women on account of perinatal ... unknown.14, 15 Immune suppression resulting from general anaesthetics ...

  16. Dynamics of epidemic diseases on a growing adaptive network.

    Science.gov (United States)

    Demirel, Güven; Barter, Edmund; Gross, Thilo

    2017-02-10

    The study of epidemics on static networks has revealed important effects on disease prevalence of network topological features such as the variance of the degree distribution, i.e. the distribution of the number of neighbors of nodes, and the maximum degree. Here, we analyze an adaptive network where the degree distribution is not independent of epidemics but is shaped through disease-induced dynamics and mortality in a complex interplay. We study the dynamics of a network that grows according to a preferential attachment rule, while nodes are simultaneously removed from the network due to disease-induced mortality. We investigate the prevalence of the disease using individual-based simulations and a heterogeneous node approximation. Our results suggest that in this system in the thermodynamic limit no epidemic thresholds exist, while the interplay between network growth and epidemic spreading leads to exponential networks for any finite rate of infectiousness when the disease persists.

  17. Epidemic spreading on random surfer networks with infected avoidance strategy

    Science.gov (United States)

    Feng, Yun; Ding, Li; Huang, Yun-Han; Guan, Zhi-Hong

    2016-12-01

    In this paper, we study epidemic spreading on random surfer networks with infected avoidance (IA) strategy. In particular, we consider that susceptible individuals’ moving direction angles are affected by the current location information received from infected individuals through a directed information network. The model is mainly analyzed by discrete-time numerical simulations. The results indicate that the IA strategy can restrain epidemic spreading effectively. However, when long-distance jumps of individuals exist, the IA strategy’s effectiveness on restraining epidemic spreading is heavily reduced. Finally, it is found that the influence of the noises from information transferring process on epidemic spreading is indistinctive. Project supported in part by the National Natural Science Foundation of China (Grant Nos. 61403284, 61272114, 61673303, and 61672112) and the Marine Renewable Energy Special Fund Project of the State Oceanic Administration of China (Grant No. GHME2013JS01).

  18. Risk from the frontlines of a hidden epidemic sexuality, masculinities ...

    African Journals Online (AJOL)

    Risk from the frontlines of a hidden epidemic sexuality, masculinities and social pressures ... It frames risk in the context of the dynamics governing sexuality, underlined ... MSM risk and practice, in these contexts, are consequently shaped by ...

  19. Hybrid epidemics--a case study on computer worm conficker.

    Directory of Open Access Journals (Sweden)

    Changwang Zhang

    Full Text Available Conficker is a computer worm that erupted on the Internet in 2008. It is unique in combining three different spreading strategies: local probing, neighbourhood probing, and global probing. We propose a mathematical model that combines three modes of spreading: local, neighbourhood, and global, to capture the worm's spreading behaviour. The parameters of the model are inferred directly from network data obtained during the first day of the Conficker epidemic. The model is then used to explore the tradeoff between spreading modes in determining the worm's effectiveness. Our results show that the Conficker epidemic is an example of a critically hybrid epidemic, in which the different modes of spreading in isolation do not lead to successful epidemics. Such hybrid spreading strategies may be used beneficially to provide the most effective strategies for promulgating information across a large population. When used maliciously, however, they can present a dangerous challenge to current internet security protocols.

  20. Hybrid epidemics--a case study on computer worm conficker.

    Science.gov (United States)

    Zhang, Changwang; Zhou, Shi; Chain, Benjamin M

    2015-01-01

    Conficker is a computer worm that erupted on the Internet in 2008. It is unique in combining three different spreading strategies: local probing, neighbourhood probing, and global probing. We propose a mathematical model that combines three modes of spreading: local, neighbourhood, and global, to capture the worm's spreading behaviour. The parameters of the model are inferred directly from network data obtained during the first day of the Conficker epidemic. The model is then used to explore the tradeoff between spreading modes in determining the worm's effectiveness. Our results show that the Conficker epidemic is an example of a critically hybrid epidemic, in which the different modes of spreading in isolation do not lead to successful epidemics. Such hybrid spreading strategies may be used beneficially to provide the most effective strategies for promulgating information across a large population. When used maliciously, however, they can present a dangerous challenge to current internet security protocols.

  1. Epidemic transmission on random mobile network with diverse infection periods

    Science.gov (United States)

    Li, Kezan; Yu, Hong; Zeng, Zhaorong; Ding, Yong; Ma, Zhongjun

    2015-05-01

    The heterogeneity of individual susceptibility and infectivity and time-varying topological structure are two realistic factors when we study epidemics on complex networks. Current research results have shown that the heterogeneity of individual susceptibility and infectivity can increase the epidemic threshold in a random mobile dynamical network with the same infection period. In this paper, we will focus on random mobile dynamical networks with diverse infection periods due to people's different constitutions and external circumstances. Theoretical results indicate that the epidemic threshold of the random mobile network with diverse infection periods is larger than the counterpart with the same infection period. Moreover, the heterogeneity of individual susceptibility and infectivity can play a significant impact on disease transmission. In particular, the homogeneity of individuals will avail to the spreading of epidemics. Numerical examples verify further our theoretical results very well.

  2. Multidimensional epidemic thresholds in diffusion processes over interdependent networks

    International Nuclear Information System (INIS)

    Salehi, Mostafa; Siyari, Payam; Magnani, Matteo; Montesi, Danilo

    2015-01-01

    Highlights: •We propose a new concept of multidimensional epidemic threshold for interdependent networks. •We analytically derive and numerically illustrate the conditions for multilayer epidemics. •We study the evolution of infection density and diffusion dynamics. -- Abstract: Several systems can be modeled as sets of interdependent networks where each network contains distinct nodes. Diffusion processes like the spreading of a disease or the propagation of information constitute fundamental phenomena occurring over such coupled networks. In this paper we propose a new concept of multidimensional epidemic threshold characterizing diffusion processes over interdependent networks, allowing different diffusion rates on the different networks and arbitrary degree distributions. We analytically derive and numerically illustrate the conditions for multilayer epidemics, i.e., the appearance of a giant connected component spanning all the networks. Furthermore, we study the evolution of infection density and diffusion dynamics with extensive simulation experiments on synthetic and real networks

  3. Underrecognition of Dengue during 2013 Epidemic in Luanda, Angola.

    Science.gov (United States)

    Sharp, Tyler M; Moreira, Rosa; Soares, Maria José; Miguel da Costa, Lúis; Mann, Jennifer; DeLorey, Mark; Hunsperger, Elizabeth; Muñoz-Jordán, Jorge L; Colón, Candimar; Margolis, Harold S; de Caravalho, Adelaide; Tomashek, Kay M

    2015-08-01

    During the 2013 dengue epidemic in Luanda, Angola, 811 dengue rapid diagnostic test-positive cases were reported to the Ministry of Health. To better understand the magnitude of the epidemic and identify risk factors for dengue virus (DENV) infection, we conducted cluster surveys around households of case-patients and randomly selected households 6 weeks after the peak of the epidemic. Of 173 case cluster participants, 16 (9%) exhibited evidence of recent DENV infection. Of 247 random cluster participants, 25 (10%) had evidence of recent DENV infection. Of 13 recently infected participants who had a recent febrile illness, 7 (54%) had sought medical care, and 1 (14%) was hospitalized with symptoms consistent with severe dengue; however, none received a diagnosis of dengue. Behavior associated with protection from DENV infection included recent use of mosquito repellent or a bed net. These findings suggest that the 2013 dengue epidemic was larger than indicated by passive surveillance data.

  4. Epidemic spreading in time-varying community networks

    International Nuclear Information System (INIS)

    Ren, Guangming; Wang, Xingyuan

    2014-01-01

    The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold q c . The epidemic will survive when q > q c and die when q  c . These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure

  5. Azañón's disease. A 19th century epidemic of neurolathyrism in Spain.

    Science.gov (United States)

    Giménez-Roldán, S; Spencer, P S

    2016-12-01

    The cultivation and consumption of grasspea (Lathyrus sativus) in Spain probably dates back centuries, especially during times of famine when the neurotoxic potential of this legume was expressed in the form of a spastic paraparesis known as neurolathyrism. Little known outside the country, the epidemic of neurolathyrism in the years following the Spanish Civil War (1936-1939) came to affect more than a thousand people. In late 1872, during the Six Years Revolutionary Term, young Alejandro San Martín Satrústegui (1847-1908), then editor of the popular weekly El Siglo Médico, travelled to Azañón, a remote village in the province of Guadalajara, to clarify a so-far unknown disease. We analysed the original article published in 1873 by San Martin, as well as communications sent by El Siglo Médico readers reporting similar cases in many other Castilian provinces. San Martín's neurological findings in seven personally examined cases were astonishingly accurate; he concluded the subjects' neurological deficits resulted from injury to the lateral columns in the lower portion of the spinal cord. Description of the clinical findings provided both by San Martín, and by the readers of El Siglo Médico, leave no doubt as to the diagnosis of neurolathyrism. However, none suspected the patient's staple food was the determinant cause of the disease. San Martín proposed the eponym Azañón's disease for lack of a better name the same year (1873) in which Cantani in Italy introduced the term lathyrism. The epidemic of neurolathyrism that affected many Castilian towns represents one of the best-documented in Europe during the last third of the 19th century. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  6. Imaging trends in suspected appendicitis-a Canadian perspective.

    Science.gov (United States)

    Tan, Victoria F; Patlas, Michael N; Katz, Douglas S

    2017-06-01

    The purpose of our study was to assess trends in the imaging of suspected appendicitis in adult patients in emergency departments of academic centers in Canada. A questionnaire was sent to all 17 academic centers in Canada to be completed by a radiologist who works in emergency radiology. The questionnaires were sent and collected over a period of 4 months from October 2015 to February 2016. Sixteen centers (94%) responded to the questionnaire. Eleven respondents (73%) use IV contrast-enhanced computed tomography (CT) as the imaging modality of choice for all patients with suspected appendicitis. Thirteen respondents (81%) use ultrasound as the first modality of choice in imaging pregnant patients with suspected appendicitis. Eleven respondents (69%) use ultrasound (US) as the first modality of choice in patients younger than 40 years of age. Ten respondents (67%) use ultrasound as the first imaging modality in female patients younger than 40 years of age. When CT is used, 81% use non-focused CT of the abdomen and pelvis, and 44% of centers use oral contrast. Thirteen centers (81%) have ultrasound available 24 h a day/7 days a week. At 12 centers (75%), ultrasound is performed by ultrasound technologists. Four centers (40%) perform magnetic resonance imaging (MRI) in suspected appendicitis in adult patients at the discretion of the attending radiologist. Eleven centers (69%) have MRI available 24/7. All 16 centers (100%) use unenhanced MRI. Various imaging modalities are available for the work-up of suspected appendicitis. Although there are North American societal guidelines and recommendations regarding the appropriateness of the multiple imaging modalities, significant heterogeneity in the first-line modalities exist, which vary depending on the patient demographics and resource availability. Imaging trends in the use of the first-line modalities should be considered in order to plan for the availability of the imaging examinations and to consider plans for

  7. Predicting and controlling infectious disease epidemics using temporal networks

    OpenAIRE

    Masuda, Naoki; Holme, Petter

    2013-01-01

    Infectious diseases can be considered to spread over social networks of people or animals. Mainly owing to the development of data recording and analysis techniques, an increasing amount of social contact data with time stamps has been collected in the last decade. Such temporal data capture the dynamics of social networks on a timescale relevant to epidemic spreading and can potentially lead to better ways to analyze, forecast, and prevent epidemics. However, they also call for extended anal...

  8. Community Size Effects on Epidemic Spreading in Multiplex Social Networks

    OpenAIRE

    Liu, Ting; Li, Ping; Chen, Yan; Zhang, Jie

    2016-01-01

    The dynamical process of epidemic spreading has drawn much attention of the complex network community. In the network paradigm, diseases spread from one person to another through the social ties amongst the population. There are a variety of factors that govern the processes of disease spreading on the networks. A common but not negligible factor is people's reaction to the outbreak of epidemics. Such reaction can be related information dissemination or self-protection. In this work, we explo...

  9. Dynamical interplay between awareness and epidemic spreading in multiplex networks

    OpenAIRE

    Granell, Clara; Gomez, Sergio; Arenas, Alex

    2013-01-01

    We present the analysis of the interrelation between two processes accounting for the spreading of an epidemics, and the information awareness to prevent its infection, on top of multiplex networks. This scenario is representative of an epidemic process spreading on a network of persistent real contacts, and a cyclic information awareness process diffusing in the network of virtual social contacts between the same individuals. The topology corresponds to a multiplex network where two diffusiv...

  10. Predicting Subnational Ebola Virus Disease Epidemic Dynamics from Sociodemographic Indicators.

    Directory of Open Access Journals (Sweden)

    Linda Valeri

    Full Text Available The recent Ebola virus disease (EVD outbreak in West Africa has spread wider than any previous human EVD epidemic. While individual-level risk factors that contribute to the spread of EVD have been studied, the population-level attributes of subnational regions associated with outbreak severity have not yet been considered.To investigate the area-level predictors of EVD dynamics, we integrated time series data on cumulative reported cases of EVD from the World Health Organization and covariate data from the Demographic and Health Surveys. We first estimated the early growth rates of epidemics in each second-level administrative district (ADM2 in Guinea, Sierra Leone and Liberia using exponential, logistic and polynomial growth models. We then evaluated how these growth rates, as well as epidemic size within ADM2s, were ecologically associated with several demographic and socio-economic characteristics of the ADM2, using bivariate correlations and multivariable regression models.The polynomial growth model appeared to best fit the ADM2 epidemic curves, displaying the lowest residual standard error. Each outcome was associated with various regional characteristics in bivariate models, however in stepwise multivariable models only mean education levels were consistently associated with a worse local epidemic.By combining two common methods-estimation of epidemic parameters using mathematical models, and estimation of associations using ecological regression models-we identified some factors predicting rapid and severe EVD epidemics in West African subnational regions. While care should be taken interpreting such results as anything more than correlational, we suggest that our approach of using data sources that were publicly available in advance of the epidemic or in real-time provides an analytic framework that may assist countries in understanding the dynamics of future outbreaks as they occur.

  11. Engaging 'communities': anthropological insights from the West African Ebola epidemic.

    Science.gov (United States)

    Wilkinson, A; Parker, M; Martineau, F; Leach, M

    2017-05-26

    The recent Ebola epidemic in West Africa highlights how engaging with the sociocultural dimensions of epidemics is critical to mounting an effective outbreak response. Community engagement was pivotal to ending the epidemic and will be to post-Ebola recovery, health system strengthening and future epidemic preparedness and response. Extensive literatures in the social sciences have emphasized how simple notions of community, which project solidarity onto complex hierarchies and politics, can lead to ineffective policies and unintended consequences at the local level, including doing harm to vulnerable populations. This article reflects on the nature of community engagement during the Ebola epidemic and demonstrates a disjuncture between local realities and what is being imagined in post-Ebola reports about the lessons that need to be learned for the future. We argue that to achieve stated aims of building trust and strengthening outbreak response and health systems, public health institutions need to reorientate their conceptualization of 'the community' and develop ways of working which take complex social and political relationships into account.This article is part of the themed issue 'The 2013-2016 West African Ebola epidemic: data, decision-making and disease control'. © 2017 The Authors.

  12. A simple model for behaviour change in epidemics

    Directory of Open Access Journals (Sweden)

    Brauer Fred

    2011-02-01

    Full Text Available Abstract Background People change their behaviour during an epidemic. Infectious members of a population may reduce the number of contacts they make with other people because of the physical effects of their illness and possibly because of public health announcements asking them to do so in order to decrease the number of new infections, while susceptible members of the population may reduce the number of contacts they make in order to try to avoid becoming infected. Methods We consider a simple epidemic model in which susceptible and infectious members respond to a disease outbreak by reducing contacts by different fractions and analyze the effect of such contact reductions on the size of the epidemic. We assume constant fractional reductions, without attempting to consider the way in which susceptible members might respond to information about the epidemic. Results We are able to derive upper and lower bounds for the final size of an epidemic, both for simple and staged progression models. Conclusions The responses of uninfected and infected individuals in a disease outbreak are different, and this difference affects estimates of epidemic size.

  13. Effects of epidemic threshold definition on disease spread statistics

    Science.gov (United States)

    Lagorio, C.; Migueles, M. V.; Braunstein, L. A.; López, E.; Macri, P. A.

    2009-03-01

    We study the statistical properties of SIR epidemics in random networks, when an epidemic is defined as only those SIR propagations that reach or exceed a minimum size sc. Using percolation theory to calculate the average fractional size of an epidemic, we find that the strength of the spanning link percolation cluster P∞ is an upper bound to . For small values of sc, P∞ is no longer a good approximation, and the average fractional size has to be computed directly. We find that the choice of sc is generally (but not always) guided by the network structure and the value of T of the disease in question. If the goal is to always obtain P∞ as the average epidemic size, one should choose sc to be the typical size of the largest percolation cluster at the critical percolation threshold for the transmissibility. We also study Q, the probability that an SIR propagation reaches the epidemic mass sc, and find that it is well characterized by percolation theory. We apply our results to real networks (DIMES and Tracerouter) to measure the consequences of the choice sc on predictions of average outcome sizes of computer failure epidemics.

  14. Parasite transmission in social interacting hosts: Monogenean epidemics in guppies

    Science.gov (United States)

    Johnson, Mirelle B.; Lafferty, Kevin D.; van Oosterhout, Cock; Cable, Joanne

    2011-01-01

    Background Infection incidence increases with the average number of contacts between susceptible and infected individuals. Contact rates are normally assumed to increase linearly with host density. However, social species seek out each other at low density and saturate their contact rates at high densities. Although predicting epidemic behaviour requires knowing how contact rates scale with host density, few empirical studies have investigated the effect of host density. Also, most theory assumes each host has an equal probability of transmitting parasites, even though individual parasite load and infection duration can vary. To our knowledge, the relative importance of characteristics of the primary infected host vs. the susceptible population has never been tested experimentally. Methodology/Principal Findings Here, we examine epidemics using a common ectoparasite, Gyrodactylus turnbulli infecting its guppy host (Poecilia reticulata). Hosts were maintained at different densities (3, 6, 12 and 24 fish in 40 L aquaria), and we monitored gyrodactylids both at a population and individual host level. Although parasite population size increased with host density, the probability of an epidemic did not. Epidemics were more likely when the primary infected fish had a high mean intensity and duration of infection. Epidemics only occurred if the primary infected host experienced more than 23 worm days. Female guppies contracted infections sooner than males, probably because females have a higher propensity for shoaling. Conclusions/Significance These findings suggest that in social hosts like guppies, the frequency of social contact largely governs disease epidemics independent of host density.

  15. Russia is on brink of AIDS epidemic.

    Science.gov (United States)

    Ingram, M

    1996-08-03

    Russia, and in particular Moscow, is on the brink of an AIDS epidemic, the president of the Russian Medical Academy told doctors gathered in Moscow for a national AIDS seminar. Although Russia has officially registered only 1269 cases of HIV infection, a quarter of them in Moscow, and 193 deaths since the first case appeared in Russia in 1987, health officials are alarmed by the recent rise in the rate of infection. In 1995, 200 new cases were registered, but 205 cases had already been registered in the first 6 months of 1996. The rapid spread of intravenous drug use is the main factor contributing to the rise in HIV infection. According to the head of the Russian AIDS Center, the real number of people infected with HIV in Russia is 3-4 times higher than official numbers, while AIDS activists believe that the real figure is 10-20 times higher. Russia has traditionally blamed its AIDS problem on foreigners and introduced an obligatory HIV test as a visa requirement for long-term visitors. Now neighboring Ukraine and Belarus are being blamed for the latest crisis. Of 1000 known intravenous drug users tested in Svetlogorsk, Belarus, 158 are HIV positive, with 20 results still outstanding. Previously, only 130 people in Belarus were known to be infected with HIV. In the Ukraine, where HIV testing has shown that over 5000 people are HIV positive and where a further 20,000 are estimated to be infected, a special subtype of HIV-1 has been discovered. In 1995 there were 1021 new cases of HIV infection, but in the first 4 months of this year there were 1805 new cases. Although the chief AIDS specialist at Russia's health ministry agrees that health education is more important than scare tactics against foreigners, in 1995 the health ministry received only 49% of the funds allocated for national AIDS education.

  16. Evidence from epidemic appraisals in Nigeria

    Directory of Open Access Journals (Sweden)

    Idoteyin O. Ezirim

    2015-10-01

    Full Text Available Although HIV prevalence has increased in most-at-risk populations (MARPs across Nigeria, effective programming was difficult because Nigeria lacked information for prevention programmes to target interventions that maximise coverage and cost effectiveness. Epidemic appraisals (EA were conducted in eight states to provide evidence for the planning, implementation and co-ordination of prevention interventions. Component 1: Mapping determined the size, typology and locations of MARPs. Component 2: Venue profiling identified and profiled venues where general populations engaged in high-risk behaviours. Component 3: Rural appraisals provided insights into risk behaviours and sexual networking in villages. States used mapping results to prioritise areas with a MARP coverage of 70% – 80% and then scale up interventions for non-brothel-based female sex workers (FSWs instead of focusing on brothel-based FSWs. The eight states prioritisedf unding for the high-coverage areas to ensure a minimum coverage level of 70% – 80% of MARPs was reached. The refocused resources led to cost efficiencies. Applying venue profiling results, six states implemented interventions at bars and night clubs – previously not covered. States also maximised intervention coverage for high-risk general populations; this led to the use of resources for general population interventions in a focused way rather than across an entire state. States focused on condom programmes in rural areas. EA results provided the evidence for focusing interventions for high MARP coverage as well as forhigh-risk general populations. The states applied the results and rapidly refocused their interventions, increasing the likelihood of having an impact on HIV transmission in those states. Nigeria is now implementing EAs in the remaining 29 states to effect national-level impact.

  17. Building partnerships to address the HIV epidemic.

    Science.gov (United States)

    Chua, A C; Leo, Y S; Lee, C C

    2008-05-01

    Batam is one of the islands comprising the Riau Province in Indonesia, and is closest to Singapore. It is a popular destination of many Singaporeans. Surveillance reports among commercial sex workers conducted in Batam showed the prevalence rate of human immunodeficiency virus (HIV) is 16.2 percent. At the end of 2006, the total number of HIV-infected Singaporeans was 3,060, the majority being infected via heterosexual transmission. The aim of the Indonesian government is to rapidly scale up HIV treatment to those needing it. One of the factors critical to the rapid scale-up is healthcare worker training. An intersectoral collaboration addressing the issue of HIV care and treatment with a hospital in Batam was created. The first activity of the collaboration was a two-day HIV training course conducted in February 2007. The aim of the course was to provide a basic understanding of HIV, as well as knowledge on common opportunistic infections that may present to a general hospital or clinical setting. 34 doctors from 23 institutions in Batam and three doctors from two hospitals in the Riau Islands attended the two-day HIV training course. The participants found the training very useful and highly relevant. This first HIV training provided a foundation to build on further HIV education. It is our belief that through the HIV training programme, there will be more awareness of HIV among the various medical institutions in Batam. As the HIV epidemic knows no borders, working with neighbouring countries is one strategy that deserves attention.

  18. Estimating the future number of cases in the Ebola epidemic--Liberia and Sierra Leone, 2014-2015.

    Science.gov (United States)

    Meltzer, Martin I; Atkins, Charisma Y; Santibanez, Scott; Knust, Barbara; Petersen, Brett W; Ervin, Elizabeth D; Nichol, Stuart T; Damon, Inger K; Washington, Michael L

    2014-09-26

    The first cases of the current West African epidemic of Ebola virus disease (hereafter referred to as Ebola) were reported on March 22, 2014, with a report of 49 cases in Guinea. By August 31, 2014, a total of 3,685 probable, confirmed, and suspected cases in West Africa had been reported. To aid in planning for additional disease-control efforts, CDC constructed a modeling tool called EbolaResponse to provide estimates of the potential number of future cases. If trends continue without scale-up of effective interventions, by September 30, 2014, Sierra Leone and Liberia will have a total of approximately 8,000 Ebola cases. A potential underreporting correction factor of 2.5 also was calculated. Using this correction factor, the model estimates that approximately 21,000 total cases will have occurred in Liberia and Sierra Leone by September 30, 2014. Reported cases in Liberia are doubling every 15-20 days, and those in Sierra Leone are doubling every 30-40 days. The EbolaResponse modeling tool also was used to estimate how control and prevention interventions can slow and eventually stop the epidemic. In a hypothetical scenario, the epidemic begins to decrease and eventually end if approximately 70% of persons with Ebola are in medical care facilities or Ebola treatment units (ETUs) or, when these settings are at capacity, in a non-ETU setting such that there is a reduced risk for disease transmission (including safe burial when needed). In another hypothetical scenario, every 30-day delay in increasing the percentage of patients in ETUs to 70% was associated with an approximate tripling in the number of daily cases that occur at the peak of the epidemic (however, the epidemic still eventually ends). Officials have developed a plan to rapidly increase ETU capacities and also are developing innovative methods that can be quickly scaled up to isolate patients in non-ETU settings in a way that can help disrupt Ebola transmission in communities. The U.S. government and

  19. Herbal hepatotoxicity: suspected cases assessed for alternative causes.

    Science.gov (United States)

    Teschke, Rolf; Schulze, Johannes; Schwarzenboeck, Alexander; Eickhoff, Axel; Frenzel, Christian

    2013-09-01

    Alternative explanations are common in suspected drug-induced liver injury (DILI) and account for up to 47.1% of analyzed cases. This raised the question of whether a similar frequency may prevail in cases of assumed herb-induced liver injury (HILI). We searched the Medline database for the following terms: herbs, herbal drugs, herbal dietary supplements, hepatotoxic herbs, herbal hepatotoxicity, and herb-induced liver injury. Additional terms specifically addressed single herbs and herbal products: black cohosh, Greater Celandine, green tea, Herbalife products, Hydroxycut, kava, and Pelargonium sidoides. We retrieved 23 published case series and regulatory assessments related to hepatotoxicity by herbs and herbal dietary supplements with alternative causes. The 23 publications comprised 573 cases of initially suspected HILI; alternative causes were evident in 278/573 cases (48.5%). Among them were hepatitis by various viruses (9.7%), autoimmune diseases (10.4%), nonalcoholic and alcoholic liver diseases (5.4%), liver injury by comedication (DILI and other HILI) (43.9%), and liver involvement in infectious diseases (4.7%). Biliary and pancreatic diseases were frequent alternative diagnoses (11.5%), raising therapeutic problems if specific treatment is withheld; pre-existing liver diseases including cirrhosis (9.7%) were additional confounding variables. Other diagnoses were rare, but possibly relevant for the individual patient. In 573 cases of initially assumed HILI, 48.5% showed alternative causes unrelated to the initially incriminated herb, herbal drug, or herbal dietary supplement, calling for thorough clinical evaluations and appropriate causality assessments in future cases of suspected HILI.

  20. How useful is gastroesophageal reflux scintigraphy in suspected childhood aspiration?

    International Nuclear Information System (INIS)

    Fawcett, H.D.; Adams, J.C.; Hayden, C.K.; Swischuk, L.E.

    1988-01-01

    It has been suggested that gastroesophageal reflux scintigraphy might be useful in assisting one in determining therapy for patients suspected of aspirating or becoming apneic secondary to gastroesophageal reflux. This, however, has not been our experience and in reviewing 23 patients with recurrent pneumonia and/or apnea who had gastroesophageal reflux scintigraphy, we were able to detect aspiration in only one. This was especially significant since 13 (59%) of these patients had demonstrable reflux, and of these, eight were treated successfully for suspected aspiration even though none was demonstrated isotopically. To be sure, the demonstration of pulmonary aspiration with gastroesophageal reflux scintigraphy had little influence on patient selection and response to therapy. For this reason we feel there is little justification in depending on the GRS for the specific purpose of trying to document pulmonary aspiration in infants and children who are refluxing. One of the more serious complications of gastroesophageal (GE) reflux is aspiration leading to recurrent pulmonary infections and/or apnea. However, it always has been difficult to demonstrate actual aspiration into the lungs, and to be sure, barium studies of the upper GI tract seldom reveal this complication. Recently, however, considerable interest has been generated in gastroesophageal scintigraphy (GRS) as a possible means of documenting such aspiration. Rationale for this stems from the fact that suspected patients can be studied over a longer period of time and in addition, delayed and overnight images can be obtained. However, our experience does not support GRS as being an adequate method for demonstrating aspiration. (orig.)

  1. Use of biomarkers in triage of patients with suspected stroke.

    Science.gov (United States)

    Vanni, Simone; Polidori, Gianluca; Pepe, Giuseppe; Chiarlone, Melisenda; Albani, Alberto; Pagnanelli, Adolfo; Grifoni, Stefano

    2011-05-01

    The absence of a rapidly available and sensitive diagnostic test represents an important limitation in the triage of patients with suspected stroke. The aim of the present study was to investigate the triage accuracy of a novel test that measures blood-borne biomarkers (triage stroke panel, TSP) and to compare its accuracy with that of the Cincinnati Prehospital Stroke Scale (CPSS). Consecutive patients with suspected stroke presenting to the Emergency Departments of three Italian hospitals underwent triage by a trained nurse according to the CPSS and had blood drawn for TSP testing. The TSP simultaneously measures four markers (B-type natriuretic peptide, D-dimer, matrix metalloproteinase-9, and S100β) presenting a single composite result, the Multimarker Index (MMX). Stroke diagnosis was established by an expert committee blinded to MMX and CPSS results. There were 155 patients enrolled, 87 (56%) of whom had a final diagnosis of stroke. The area under the receiver operating characteristic (ROC) curve for CPSS was 0.77 (95% confidence interval [CI] 0.70-0.84) and that of MMX was 0.74 (95% CI 0.66-0.82) (p = 0.285). Thus, both tests, when used alone, failed to recognize approximately 25% of strokes. The area under the ROC curve of the combination of the two tests (0.86, 95% CI 0.79-0.91) was significantly greater than that of either single test (p = 0.01 vs. CPSS and p vs. TSP). In an emergency care setting, a panel test using multiple biochemical markers showed triage accuracy similar to that of CPSS. Further studies are needed before biomarkers can be introduced in the clinical work-up of patients with suspected stroke. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. A Suspected Pelvic Aneurysmal Bone Cyst in Pregnancy

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    Rayan Elkattah

    2013-01-01

    Full Text Available Albeit rare, the majority of identified bone lesions in pregnancy spare the pelvis. Once encountered with a pelvic bone lesion in pregnancy, the obstetrician may face a challenging situation as it is difficult to determine and predict the effects that labor and parturition impart on the pelvic bones. Bone changes and pelvic bone fractures have been well documented during childbirth. The data regarding clinical outcomes and management of pregnancies complicated by pelvic ABCs is scant. Highly suspected to represent an aneurysmal bone cyst, the clinical evaluation of a pelvic lesion in the ilium of a pregnant individual is presented, and modes of delivery in such a scenario are discussed.

  3. Investigation of suspected TRALI cases in 2006–2011

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    Marjeta Maček Kvanka

    2012-12-01

    Methods: In 2006–2011, eight suspected TRALI cases that met consensus clinical criteria and had chest radiograph were investigated in the Blood Transfusion Center of Slovenia. Patients and all donors of blood components transfused within 6 hours before the onset of acute respiratory distress were investigated for leukocyte antibodies against HLA class I and II antigens, and antibodies against neutrophil antigens HNA. All cases were investigated for patient, donor and blood component characteristics. In cooperation with clinicians, chest radiographs and alternative risk factors for acute lung injury (ALI were evaluated.

  4. Creating fair lineups for suspects with distinctive features.

    Science.gov (United States)

    Zarkadi, Theodora; Wade, Kimberley A; Stewart, Neil

    2009-12-01

    In their descriptions, eyewitnesses often refer to a culprit's distinctive facial features. However, in a police lineup, selecting the only member with the described distinctive feature is unfair to the suspect and provides the police with little further information. For fair and informative lineups, the distinctive feature should be either replicated across foils or concealed on the target. In the present experiments, replication produced more correct identifications in target-present lineups--without increasing the incorrect identification of foils in target-absent lineups--than did concealment. This pattern, and only this pattern, is predicted by the hybrid-similarity model of recognition.

  5. Cytogenetic dosimetry in suspected cases of ionizing radiation occupational exposure

    International Nuclear Information System (INIS)

    Ramalho, Adriana T.; Costa, Maria Lucia P.; Oliveira, Monica S.; Silva, Francisco Cesar A. da

    2001-01-01

    Cytogenetic dosimetry is very useful in routine as well as in serious accident situations in which exposed individuals do not wear physical dosimeters. Since 1984, the technique of cytogenetic dosimetry has been used as a routine in our laboratory at IRD/CNEN to complement the data of physical dosimetry. In the period from 1984 to 2000, 138 cases of occupational overexposure of individual dosimeters were investigated by us. In total, only in 36 of the 138 cases investigated the overexposure was confirmed by cytogenetic dosimetry. The data indicates a total confirmation index of just 26% of the suspected cases.(author)

  6. Could the Recent Zika Epidemic Have Been Predicted?

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    Ángel G. Muñoz

    2017-07-01

    Full Text Available Given knowledge at the time, the recent 2015–2016 zika virus (ZIKV epidemic probably could not have been predicted. Without the prior knowledge of ZIKV being already present in South America, and given the lack of understanding of key epidemiologic processes and long-term records of ZIKV cases in the continent, the best related prediction could be carried out for the potential risk of a generic Aedes-borne disease epidemic. Here we use a recently published two-vector basic reproduction number model to assess the predictability of the conditions conducive to epidemics of diseases like zika, chikungunya, or dengue, transmitted by the independent or concurrent presence of Aedes aegypti and Aedes albopictus. We compare the potential risk of transmission forcing the model with the observed climate and with state-of-the-art operational forecasts from the North American Multi Model Ensemble (NMME, finding that the predictive skill of this new seasonal forecast system is highest for multiple countries in Latin America and the Caribbean during the December-February and March-May seasons, and slightly lower—but still of potential use to decision-makers—for the rest of the year. In particular, we find that above-normal suitable conditions for the occurrence of the zika epidemic at the beginning of 2015 could have been successfully predicted at least 1 month in advance for several zika hotspots, and in particular for Northeast Brazil: the heart of the epidemic. Nonetheless, the initiation and spread of an epidemic depends on the effect of multiple factors beyond climate conditions, and thus this type of approach must be considered as a guide and not as a formal predictive tool of vector-borne epidemics.

  7. Could the Recent Zika Epidemic Have Been Predicted?

    Science.gov (United States)

    Vecchi, G. A.; Munoz, A. G.; Thomson, M. C.; Stewart-Ibarra, A. M.; Chourio, X.; Nájera, P.; Moran, Z.; Yang, X.

    2017-12-01

    Given knowledge at the time, the recent 2015-2016 zika virus (ZIKV) epidemic probably could not have been predicted. Without the prior knowledge of ZIKV being already present in South America, and given the lack of understanding of key epidemiologic processes and long-term records of ZIKV cases in the continent, the best related prediction could be carried out for the potential risk of a generic Aedes-borne disease epidemic. Here we use a recently published two-vector basic reproduction number model to assess the predictability of the conditions conducive to epidemics of diseases like zika, chikungunya, or dengue, transmitted by the independent or concurrent presence of Aedes aegypti and Aedes albopictus. We compare the potential risk of transmission forcing the model with the observed climate and with state-of-the-art operational forecasts from the North American Multi Model Ensemble (NMME), finding that the predictive skill of this new seasonal forecast system is highest for multiple countries in Latin America and the Caribbean during the December-February and March-May seasons, and slightly lower—but still of potential use to decision-makers—for the rest of the year. In particular, we find that above-normal suitable conditions for the occurrence of the zika epidemic at the beginning of 2015 could have been successfully predicted at least 1 month in advance for several zika hotspots, and in particular for Northeast Brazil: the heart of the epidemic. Nonetheless, the initiation and spread of an epidemic depends on the effect of multiple factors beyond climate conditions, and thus this type of approach must be considered as a guide and not as a formal predictive tool of vector-borne epidemics.

  8. Flexible Modeling of Epidemics with an Empirical Bayes Framework

    Science.gov (United States)

    Brooks, Logan C.; Farrow, David C.; Hyun, Sangwon; Tibshirani, Ryan J.; Rosenfeld, Roni

    2015-01-01

    Seasonal influenza epidemics cause consistent, considerable, widespread loss annually in terms of economic burden, morbidity, and mortality. With access to accurate and reliable forecasts of a current or upcoming influenza epidemic’s behavior, policy makers can design and implement more effective countermeasures. This past year, the Centers for Disease Control and Prevention hosted the “Predict the Influenza Season Challenge”, with the task of predicting key epidemiological measures for the 2013–2014 U.S. influenza season with the help of digital surveillance data. We developed a framework for in-season forecasts of epidemics using a semiparametric Empirical Bayes framework, and applied it to predict the weekly percentage of outpatient doctors visits for influenza-like illness, and the season onset, duration, peak time, and peak height, with and without using Google Flu Trends data. Previous work on epidemic modeling has focused on developing mechanistic models of disease behavior and applying time series tools to explain historical data. However, tailoring these models to certain types of surveillance data can be challenging, and overly complex models with many parameters can compromise forecasting ability. Our approach instead produces possibilities for the epidemic curve of the season of interest using modified versions of data from previous seasons, allowing for reasonable variations in the timing, pace, and intensity of the seasonal epidemics, as well as noise in observations. Since the framework does not make strict domain-specific assumptions, it can easily be applied to some other diseases with seasonal epidemics. This method produces a complete posterior distribution over epidemic curves, rather than, for example, solely point predictions of forecasting targets. We report prospective influenza-like-illness forecasts made for the 2013–2014 U.S. influenza season, and compare the framework’s cross-validated prediction error on historical data to

  9. Is the New Heroin Epidemic Really New? Racializing Heroin.

    Science.gov (United States)

    Bowser, Benjamin; Fullilove, Robert; Word, Carl

    2017-01-01

    Heroin abuse as an outcome of the prior use of painkillers increased rapidly over the past decade. This "new epidemic" is unique because the new heroin users are primarily young White Americans in rural areas of virtually every state. This commentary argues that the painkiller-to-heroin transition could not be the only cause of heroin use on such a scale and that the new and old heroin epidemics are linked. The social marketing that so successfully drove the old heroin epidemic has innovated and expanded due to the use of cell-phones, text messaging and the "dark web" which requires a Tor browser, and software that allows one to communicate with encrypted sites without detection. Central city gentrification has forced traffickers to take advantage of larger and more lucrative markets. A second outcome is that urban black and Latino communities are no longer needed as heroin stages areas for suburban and exurban illicit drug distribution. Drug dealing can be done directly in predominantly white suburbs and rural areas without the accompanying violence associated with the old epidemic. Denial of the link between the new and old heroin epidemics racially segregates heroin users and more proactive prevention and treatment in the new epidemic than in the old. It also cuts off a half-century of knowledge about the supply-side of heroin drug dealing and the inevitable public policy measures that will have to be implemented to effectively slow and stop both the old and new epidemic. Copyright © 2016 National Medical Association. Published by Elsevier Inc. All rights reserved.

  10. On the Use of Human Mobility Proxies for Modeling Epidemics

    Science.gov (United States)

    Tizzoni, Michele; Bajardi, Paolo; Decuyper, Adeline; Kon Kam King, Guillaume; Schneider, Christian M.; Blondel, Vincent; Smoreda, Zbigniew; González, Marta C.; Colizza, Vittoria

    2014-01-01

    Human mobility is a key component of large-scale spatial-transmission models of infectious diseases. Correctly modeling and quantifying human mobility is critical for improving epidemic control, but may be hindered by data incompleteness or unavailability. Here we explore the opportunity of using proxies for individual mobility to describe commuting flows and predict the diffusion of an influenza-like-illness epidemic. We consider three European countries and the corresponding commuting networks at different resolution scales, obtained from (i) official census surveys, (ii) proxy mobility data extracted from mobile phone call records, and (iii) the radiation model calibrated with census data. Metapopulation models defined on these countries and integrating the different mobility layers are compared in terms of epidemic observables. We show that commuting networks from mobile phone data capture the empirical commuting patterns well, accounting for more than 87% of the total fluxes. The distributions of commuting fluxes per link from mobile phones and census sources are similar and highly correlated, however a systematic overestimation of commuting traffic in the mobile phone data is observed. This leads to epidemics that spread faster than on census commuting networks, once the mobile phone commuting network is considered in the epidemic model, however preserving to a high degree the order of infection of newly affected locations. Proxies' calibration affects the arrival times' agreement across different models, and the observed topological and traffic discrepancies among mobility sources alter the resulting epidemic invasion patterns. Results also suggest that proxies perform differently in approximating commuting patterns for disease spread at different resolution scales, with the radiation model showing higher accuracy than mobile phone data when the seed is central in the network, the opposite being observed for peripheral locations. Proxies should therefore be

  11. Efficacy of Carbopol 974P (Siccafluid in the treatment of severe to moderate keratoconjunctivitis sicca (KCS in patients with primary Sjögren’s syndrome (SS not responding to standard treatment with artificial tears

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    A. Furlan

    2011-09-01

    Full Text Available Objective. To determine efficacy and safety of Carbopol 974P in the treatment of severe to moderate keratoconjunctivitis sicca (KCS in patients with primary Sjögren’s syndrome (SS not responding to standard treatment with artificial tears. Methods. 60 patients (57 F, 3 M, mean age 52.5±12.0, mean disease duration 12.2±7.1 yrs affected with primary SS diagnosed according to the European Community Study Group criteria were studied. Foregoing medications for SS and artificial tears for KCS have not been changed within 3 and 2 months respectively prior to the study onset. In all cases Carbopol 974P was added because symptoms of KCS were not adequately controlled with traditional lubricants. Schirmer I test, B.U.T. (break up time, rose Bengal-stain, clinical ophthalmological examination (i.e. fluorescein staining, keratis, corneal infiltrates and ulcers and a questionnaire for dry eye symptoms (range 0-30 were performed at entry (T0 and after 2 (T1 and 12 (T2 weeks. Assessment of global efficacy was obtained by VAS 0-100 at T2 either by patients and by the ophthalmologist. Results. Lachrymal tests significantly improved after 2 and, even more, after 12 weeks. Clinical ophthalmologic picture also ameliorated: a remarkable reduction of fluorescein positive lesions was demonstrated from 71.6% of the cases at T0 to 38.3% at T2. Total score of symptoms (T0: 16.1±7.3 dropped to 11.9±6.6 (T1 (p=0.000 and then to 6.7±5.3 (T2 (p=0.000. Global efficacy expressed by patients and physician was 74.8±15.9 and 76.6±13.0, respectively. No adverse events (blurred vision, allergy were reported throughout the study. Conclusions. Our study seems to demonstrate that addition of Carbopol 974P to the traditional therapeutic armamentarium for moderate to severe KCS is useful and well accepted in patients with primary SS in which management of ocular symptoms is unsatisfactory.

  12. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania.

    Science.gov (United States)

    Mweya, Clement N; Kimera, Sharadhuli I; Mellau, Lesakit S B; Mboera, Leonard E G

    2015-01-01

    Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC) light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. A total of 1,823 mosquitoes were collected, of which 87% (N=1,588) were Culex pipiens complex, 12% (N=226) Aedes aegypti, and 0.5% (N=9) Anopheles species. About two-thirds (67%; N=1,095) of C. pipiens complex and nearly 100% (N=225) of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78%) of C. pipiens complex and most (85%) of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania.

  13. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania

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    Clement N. Mweya

    2015-01-01

    Full Text Available Background: Rift Valley fever (RVF is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. Objective: To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. Methods: A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. Results: A total of 1,823 mosquitoes were collected, of which 87% (N=1,588 were Culex pipiens complex, 12% (N=226 Aedes aegypti, and 0.5% (N=9 Anopheles species. About two-thirds (67%; N=1,095 of C. pipiens complex and nearly 100% (N=225 of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78% of C. pipiens complex and most (85% of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. Conclusions: These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania.

  14. The Potential Impact of Up-Front Drug Sensitivity Testing on India's Epidemic of Multi-Drug Resistant Tuberculosis.

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    Kuldeep Singh Sachdeva

    Full Text Available In India as elsewhere, multi-drug resistance (MDR poses a serious challenge in the control of tuberculosis (TB. The End TB strategy, recently approved by the world health assembly, aims to reduce TB deaths by 95% and new cases by 90% between 2015 and 2035. A key pillar of this approach is early diagnosis of tuberculosis, including use of higher-sensitivity diagnostic testing and universal rapid drug susceptibility testing (DST. Despite limitations of current laboratory assays, universal access to rapid DST could become more feasible with the advent of new and emerging technologies. Here we use a mathematical model of TB transmission, calibrated to the TB epidemic in India, to explore the potential impact of a major national scale-up of rapid DST. To inform key parameters in a clinical setting, we take GeneXpert as an example of a technology that could enable such scale-up. We draw from a recent multi-centric demonstration study conducted in India that involved upfront Xpert MTB/RIF testing of all TB suspects.We find that widespread, public-sector deployment of high-sensitivity diagnostic testing and universal DST appropriately linked with treatment could substantially impact MDR-TB in India. Achieving 75% access over 3 years amongst all cases being diagnosed for TB in the public sector alone could avert over 180,000 cases of MDR-TB (95% CI 44187 - 317077 cases between 2015 and 2025. Sufficiently wide deployment of Xpert could, moreover, turn an increasing MDR epidemic into a diminishing one. Synergistic effects were observed with assumptions of simultaneously improving MDR-TB treatment outcomes. Our results illustrate the potential impact of new and emerging technologies that enable widespread, timely DST, and the important effect that universal rapid DST in the public sector can have on the MDR-TB epidemic in India.

  15. Incidence rates of enterovirus 71 infections in young children during a nationwide epidemic in Taiwan, 2008-09.

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    Min-Shi Lee

    Full Text Available OBJECTIVE: Enterovirus 71 (EV71 is causing life-threatening outbreaks in tropical Asia. In Taiwan and other tropical Asian countries, although nationwide EV71 epidemics occur cyclically, age-specific incidence rates of EV71 infections that are critical to estimate disease burden and design vaccine trials are not clear. A nationwide EV71 epidemic occurred in 2008-09 in Taiwan, which provided a unique opportunity to estimate age-specific incidence rates of EV71 infections. STUDY DESIGN: We prospectively recruited 749 healthy neonates and conducted follow-ups from June 2006 to December 2009. Sera were obtained from participants at 0, 6, 12, 24, and 36 months of age for measuring EV71 neutralizing antibody titers. If the participants developed suspected enterovirus illnesses, throat swabs were collected for virus isolation. RESULTS: We detected 28 EV71 infections including 20 symptomatic and 8 asymptomatic infections. Age-specific incidence rates of EV71 infection increased from 1.71 per 100 person-years at 0-6 months of age to 4.09, 5.74, and 4.97 per 100 person-years at 7-12, 13-24, and 25-36 months of age, respectively. Cumulative incidence rate was 15.15 per 100 persons by 36 months of age, respectively. CONCLUSIONS: Risk of EV71 infections in Taiwan increased after 6 months of age during EV71 epidemics. The cumulative incidence rate was 15% by 36 months of age, and 29% of EV71 infections were asymptomatic in young children.

  16. Epidemic myalgia and myositis associated with human parechovirus type 3 infections occur not only in adults but also in children: findings in Yamagata, Japan, 2014.

    Science.gov (United States)

    Mizuta, K; Yamakawa, T; Kurokawa, K; Chikaoka, S; Shimizu, Y; Itagaki, T; Katsushima, F; Katsushima, Y; Ito, S; Aoki, Y; Matoba, Y; Tanaka, S; Yahagi, K

    2016-04-01

    We previously reported an association between human parechovirus type 3 (HPeV3) and epidemic myalgia with myositis in adults during summers in which an HPeV3 outbreak occurred in children. However, this disease association has not yet been reported elsewhere. We have since continued our surveillance to accumulate data on this disease association and to confirm whether myalgia occurs in children as well as adults. Between June and August 2014, we collected 380 specimens from children with infectious diseases. We also collected clinical specimens from two adult and three paediatric patients suspected of myalgia. We then performed virus isolation and reverse-transcription-PCR using the collected specimens. We detected HPeV3 in 26 children with infectious diseases, which we regarded as indicating an outbreak. We also confirmed HPeV3 infection in all patients suspected of myalgia. In particular the symptoms in two boys, complaining of myalgia and fever, closely matched the criteria for adult myalgia. Based on our findings from 2008, 2011 and 2014, we again urge that clinical consideration be given to the relationship between myalgia and HPeV3 infections during HPeV3 outbreaks in children. Furthermore, our observations from 2014 suggest that epidemic myalgia and myositis occur not only in adults but also in children.

  17. Clinical Survey of Dengue Virus Circulation in the Republic of Djibouti between 2011 and 2014 Identifies Serotype 3 Epidemic and Recommends Clinical Diagnosis Guidelines for Resource Limited Settings.

    Science.gov (United States)

    Le Gonidec, Erwan; Maquart, Marianne; Duron, Sandrine; Savini, Hélène; Cazajous, Geraldine; Vidal, Pierre-Olivier; Chenilleau, Marie-Caroline; Roseau, Jean-Baptiste; Benois, Alain; Dehan, Céline; Kugelman, Jeffrey; Leparc-Goffart, Isabelle; Védy, Serge

    2016-06-01

    Dengue virus is endemic globally, throughout tropical and sub-tropical regions. While the number of epidemics due to the four DENV serotypes is pronounced in East Africa, the total number of cases reported in Africa (16 million infections) remained at low levels compared to Asia (70 million infections). The French Armed forces Health Service provides epidemiological surveillance support in the Republic of Djibouti through the Bouffard Military hospital. Between 2011 and 2014, clinical and biological data of suspected dengue syndromes were collected at the Bouffard Military hospital and analyzed to improve Dengue clinical diagnosis and evaluate its circulation in East Africa. Examining samples from patients that presented one or more Dengue-like symptoms the study evidenced 128 Dengue cases among 354 suspected cases (36.2% of the non-malarial Dengue-like syndromes). It also demonstrated the circulation of serotypes 1 and 2 and reports the first epidemic of serotype 3 infections in Djibouti which was found in all of the hospitalized patients in this study. Based on these results we have determined that screening for Malaria and the presence of the arthralgia, gastro-intestinal symptoms and lymphopenia Djibouti.

  18. A case of suspected 'Bickerstaff's encephalitis' and its CT findings

    International Nuclear Information System (INIS)

    Moto, Atsufumi; Endo, Shunro; Ohmori, Tomoaki; Oka, Nobuo; Takaku, Akira

    1985-01-01

    A case of suspected ''Bickerstaff's encephalitis'' was presented with special reference to the CT findings. A 4-year-old girl exhibited fever and nausea after the beginning of December, 1983, followed by unsteady gait on January 1, 1984. She was admitted to another hospital and diagnosed by means of a spinalfluid examination as having aseptic meningitis. Her symptoms subsided transiently, but then she began again to suffer recurrently from unsteady gait on January 27. After that she developed dysarthria and dysphagia, a disturbance of eye movement was observed, and she became lethargic and disoriented. On February 6, she was transferred to our hospital. Plain CT scan on admission revealed a low-density area on the left cerebellar peduncle and the inferior medial part of the left temporal lobe. Moreover, the low-density area was heterogenously enhanced with the contrast medium. Angiography showed no abnormal findings. Considering these CT findings, we suspected a pontine tumor. Four days after her admission, however, her symptoms and signs began rapidly to subside, and also the abnormal findings on the CT scan diminished gradually as the symptoms were relieved. On March 2, she was discharged without any neurological abnormality. (author)

  19. PMS2 involvement in patients suspected of Lynch syndrome.

    Science.gov (United States)

    Niessen, Renée C; Kleibeuker, Jan H; Westers, Helga; Jager, Paul O J; Rozeveld, Dennie; Bos, Krista K; Boersma-van Ek, Wytske; Hollema, Harry; Sijmons, Rolf H; Hofstra, Robert M W

    2009-04-01

    It is well-established that germline mutations in the mismatch repair genes MLH1, MSH2, and MSH6 cause Lynch syndrome. However, mutations in these three genes do not account for all Lynch syndrome (suspected) families. Recently, it was shown that germline mutations in another mismatch repair gene, PMS2, play a far more important role in Lynch syndrome than initially thought. To explore this further, we determined the prevalence of pathogenic germline PMS2 mutations in a series of Lynch syndrome-suspected patients. Ninety-seven patients who had early-onset microsatellite instable colorectal or endometrial cancer, or multiple Lynch syndrome-associated tumors and/or were from an Amsterdam Criteria II-positive family were selected for this study. These patients carried no pathogenic germline mutation in MLH1, MSH2, or MSH6. When available, tumors were investigated for immunohistochemical staining (IHC) for PMS2. PMS2 was screened in all patients by exon-by-exon sequencing. We identified four patients with a pathogenic PMS2 mutation (4%) among the 97 patients we selected. IHC of PMS2 was informative in one of the mutation carriers, and in this case, the tumor showed loss of PMS2 expression. In conclusion, our study confirms the finding of previous studies that PMS2 is more frequently involved in Lynch syndrome than originally expected.

  20. Investigation of suspected chronic fatigue syndrome/myalgic encephalopathy.

    Science.gov (United States)

    Owe, Jone Furlund; Næss, Halvor; Gjerde, Ivar Otto; Bødtker, Jørn Eilert; Tysnes, Ole-Bjørn

    2016-02-09

    Chronic fatigue is a frequently occurring problem in both the primary and specialist health services. The Department of Neurology at Haukeland University Hospital has established a standard assessment for patients referred with suspected CFS/ME. This study reports diagnoses and findings upon assessment, and considers the benefit of supplementary examinations. Diagnoses and findings from examinations of 365 patients assessed for suspected CFS/ME are retrospectively reported. A total of 48 patients (13.2%) were diagnosed with CFS/ME, while a further 18 patients (4.9%) were diagnosed with post-infectious fatigue. Mental and behavioural disorders were diagnosed in 169 patients (46.3%), and these represented by far the largest group. Serious, but unrecognised somatic illness was discovered in two patients, while changes of uncertain significance were identified by MRI and lumbar puncture in a few patients. Fatigue is a frequently occurring symptom in the population. Thorough somatic and psychiatric investigation is necessary before referral to the specialist health services. Mental disorders and reactions to life crises are common and important differential diagnoses for CFS/ME. Long waiting times in the specialist health services may result in delayed diagnosis for these patients.

  1. The role of MRI in suspected inner ear malformations

    International Nuclear Information System (INIS)

    Koesling, S.; Juettemann, S.; Amaya, B.; Rasinski, C.; Bloching, M.; Koenig, E.

    2003-01-01

    Purpose: This is a prospective analysis of the value of MRI in suspected inner ear malformations. Materials and Methods: In 50 patients (43 children and young adults, 7 adults) with suspected inner ear malformation MRI (1.5 T) was performed. In addition, 42 of these patients underwent CT. For the analysis of the inner ear structures, the constructive interference in steady state (CISS) sequence with 0.7 mm slice thickness was used. Functional tests revealed a sensorineural hearing loss or deafness in 82 temporal bones (TB) and a combined hearing loss in 4 TB. The hearing loss was unilateral in 14 patients. MRI and CT findings were compared. Results: Imaging findings were normal in 58 TB. The pathological findings included inner ear malformations (35 TB), inflammatory changes (4 TB), partial obliteration of labyrinth (2 TB) and congenital aural atresia (1 TB). An isolated absence of the cochlear nerve (1 TB) could only be found by MRI. In the remaining cases, an inner ear malformation was diagnosed by MRI and CT with the same confidence but MRI was superior in displaying the fine details. Conclusions: MRI will become the method of choice in the diagnosis of inner ear malformations. (orig.) [de

  2. Early diagnosis of dengue virus infection in clinically suspected cases

    International Nuclear Information System (INIS)

    Afridi, N.K.; Ahmed, S.; Ali, N.; Khan, S.A.

    2016-01-01

    Objective: Comparison of real time reverse transcriptase polymerase chain reaction (RTPCR) and immunoglobulin M (IgM) capture enzyme linked immunosorbent assay (ELISA) for diagnosis of dengue virus infection in first week of illness in clinically suspected patients of dengue fever. Study Design: Cross sectional study. Place and Duration of Study: Department of haematology, Armed Forces Institute of Pathology (AFIP) Rawalpindi from Jan 2013 to Nov 2013. Material and Methods: A cross sectional study including 68 clinically suspected patients of dengue fever according to the World Health Organization (WHO) criteria. IgM capture ELISA and RT PCR for dengue virus ribonucleic acid (RNA) was performed on samples collected from patients having fever for 1 to 7 days. These were divided into two groups. Patients in group 1 presented with fever of 4 days or less, patients in group 2 had fever of 5 to 7 days duration. Results: In group 1, 72 percent of the patients were positive by RT PCR while 31 percent were positive by IgM capture ELISA. In group 2, 43 percent of the patients were positive by RT PCR while 97 percent were positive by ELISA. Conclusion: RT PCR can be used for early detection of dengue virus infection in the first few days of fever while IgM ELISA is diagnostic afterwards. (author)

  3. MRI diagnosis of suspected atlanto-occipital dissociation in childhood

    International Nuclear Information System (INIS)

    Grabb, B.C.; Frye, T.A.; Hedlund, G.L.; Vaid, Y.N.; Royal, S.A.; Grabb, P.A.

    1999-01-01

    Objective. To demonstrate the utility of magnetic resonance (MR) imaging in the diagnosis of complete and partial ligamentous injuries in patients with suspected atlanto-occipital dissociation (AOD). Materials and methods. Five patients with suspected AOD had MR imaging performed within an average of 4 days after injury. MR scans were reviewed with specific analysis of craniocervical ligamentous structures. Charts were reviewed to obtain clinical information regarding presentation, treatment, hospital course, and outcome. Results. Two patients demonstrated MR evidence of complete AOD. One had disruption of all visualized major ligamentous structures at the craniocervical junction with anterolisthesis and evidence of cord damage. The second had injuries to the tectorial membrane, superior band of the cruciform ligament, apical ligament, and interspinous ligament at C 1-2. The remaining three patients sustained incomplete severance of the ligamentous structures at the craniocervical junction. All patients demonstrated subtle radiographic findings suggestive of AOD, including soft tissue swelling at the craniocervical junction without fracture. The two patients with complete AOD died. The three patients with partial AOD were treated with stabilization. On follow-up, these three children were asymptomatic following their craniocervical injury. Conclusion. MR imaging of acute AOD provides accurate identification of the craniocervical ligaments injured, classification of full versus partial ligamentous disruption, and analysis of accompanying spinal cord injury. This information is important for early appropriate neurosurgical management and preservation of neurologic function in survivors. (orig.)

  4. CT coronary angiographic evaluation of suspected anginal chest pain.

    Science.gov (United States)

    Moss, Alastair J; Newby, David E

    2016-02-15

    Non-invasive imaging plays a critical role in the assessment of patients presenting with suspected angina chest pain. However, wide variations in practice across Europe and North America highlight the lack of consensus in selecting the appropriate first-line test for the investigation of coronary artery disease (CAD). CT coronary angiography (CTCA) has a high negative predictive value for excluding the presence of CAD. As such, it serves as a potential 'gatekeeper' to downstream testing by reducing the rate of inappropriate invasive coronary angiography. Two recent large multicentre randomised control trials have provided insights into whether CTCA can be incorporated into chest pain care pathways to improve risk stratification of CAD. They demonstrate that using CTCA enhances diagnostic certainty and improves the targeting of appropriate invasive investigations and therapeutic interventions. Importantly, reductions in cardiac death and non-fatal myocardial infarction appear to be attained through the more appropriate use of preventative therapy and coronary revascularisation when guided by CTCA. With this increasing portfolio of evidence, CTCA should be considered the non-invasive investigation of choice in the evaluation of patients with suspected angina pectoris due to coronary heart disease. NCT01149590, post-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  5. Value of noncontrast spiral CT for suspected acute appendicitis

    International Nuclear Information System (INIS)

    Choi, Pil Yeob; Lee, Sang Wook; Kwon, Jae Soo; Sung, Young Soon; Rho, Myoung Ho; Chang, Jeong A.

    1998-01-01

    To assess the diagnostic accuracy and clinical efficacy of noncontrast spiral CT in patients with suspected acute appendicitis. Over a six-month period, 100 patients with suspected acute appendicitis were prospectively evaluated with noncontrast spiral CT. All scans were obtained from the lower body of L3 to the symphysis pubis, with 5mm or 10mm collimation and pitch of 1 or 1.5, and without intravenous or oral contrast material. Diagnosis was established by means of surgical or clinical follow-up. Prospective diagnosis based on CT findings was compared with surgical results and clinical follow-up. Acute appendicitis was confirmed in 47 of 100 patients. On the basis of the Ct findings, SI patients were prospectively interpreted as positive for appendicitis, but in six the diagnosis was false-positive. Two of the 47 with acute appendicitis were prospectively interpreted as normal. The preoperative diagnosis of acute appendicitis was, thus, 45 true-positive, 47 true-negative, six false-positive and two false-negative yielding a sensitivity of 96%, a specificity of 89%, an accuracy of 92%, a positive predictive value of 88%, and a negative predictive value of 96%. Using CT, an alternative diagnosis was established in 14 patients. Noncontrast spiral CT is a useful technique for diagnosing acute appendicitis. =20

  6. Epidemic dengue 2 in the city of Djibouti 1991-1992.

    Science.gov (United States)

    Rodier, G R; Gubler, D J; Cope, S E; Cropp, C B; Soliman, A K; Polycarpe, D; Abdourhaman, M A; Parra, J P; Maslin, J; Arthur, R R

    1996-01-01

    From October 1991 to February 1992, an outbreak of acute fever (in which thick blood films were negative for malaria) spread rapidly in the city of Djibouti, Djibouti Republic, affecting all age groups and both nationals and foreigners. The estimated number of cases was 12,000. The clinical features were consistent with a non-haemorrhagic dengue-like illness. Serum samples from 91 patients were analysed serologically for flavivirus infection (dengue 1-4, West Nile, yellow fever, Zika, Banzi, and Uganda-S), and virus isolation was attempted. Twelve strains of dengue 2 virus were isolated. Dengue infection was confirmed by a 4-fold or greater rise in immunoglobulin (Ig) G antibody in paired serum specimens, the presence of IgM antibody, or isolation of the virus. Overall, 46 of the suspected cases (51%) were confirmed virologically or had serological evidence of a recent flavivirus infection. Statistical analysis showed that the presence of a rash was the best predictor of flavivirus seropositivity. In November 1992, Aedes aegypti was widespread and abundant in several districts of Djibouti city. A serological study of serum samples collected from Djiboutian military personnel 5 months before the epidemic showed that only 15/177 (8.5%) had flavivirus antibodies. These findings, together with a negative serosurvey for dengue serotypes 1-4 and yellow fever virus performed in 1987, support the conclusion that dengue 2 virus has only recently been introduced to Djibouti.

  7. Method for detection of a suspect viral deoxyribonucleic acid in an acellular biological fluid

    Energy Technology Data Exchange (ETDEWEB)

    Berninger, M S

    1982-10-06

    A method for evaluating an acellular biological fluid for the presence of a suspect viral DNA, such as DNA of the Hepatitis-B virus, is described. The acellular biological fluid is treated to immobilize in denatured form the DNAs including the suspect viral DNA on a solid substrate. This substrate is contacted with a solution including radioisotopically-labelled suspect viral denatured DNA to renature the immobilized suspect viral native DNA. The solid substrate is then evaluated for radioisotopically-labelled suspect viral renatured DNA.

  8. Method for detection of a suspect viral deoxyribonucleic acid in an acellular biological fluid

    International Nuclear Information System (INIS)

    Berninger, M.S.

    1982-01-01

    A method for evaluating an acellular biological fluid for the presence of a suspect viral DNA, such as DNA of the Hepatitis-B virus, is described. The acellular biological fluid is treated to immobilize in denatured form the DNAs including the suspect viral DNA on a solid substrate. This substrate is contacted with a solution including radioisotopically-labelled suspect viral denatured DNA to renature the immobilized suspect viral native DNA. The solid substrate is then evaluated for radioisotopically-labelled suspect viral renatured DNA. (author)

  9. Nonlinear model of epidemic spreading in a complex social network.

    Science.gov (United States)

    Kosiński, Robert A; Grabowski, A

    2007-10-01

    The epidemic spreading in a human society is a complex process, which can be described on the basis of a nonlinear mathematical model. In such an approach the complex and hierarchical structure of social network (which has implications for the spreading of pathogens and can be treated as a complex network), can be taken into account. In our model each individual has one of the four permitted states: susceptible, infected, infective, unsusceptible or dead. This refers to the SEIR model used in epidemiology. The state of an individual changes in time, depending on the previous state and the interactions with other individuals. The description of the interpersonal contacts is based on the experimental observations of the social relations in the community. It includes spatial localization of the individuals and hierarchical structure of interpersonal interactions. Numerical simulations were performed for different types of epidemics, giving the progress of a spreading process and typical relationships (e.g. range of epidemic in time, the epidemic curve). The spreading process has a complex and spatially chaotic character. The time dependence of the number of infective individuals shows the nonlinear character of the spreading process. We investigate the influence of the preventive vaccinations on the spreading process. In particular, for a critical value of preventively vaccinated individuals the percolation threshold is observed and the epidemic is suppressed.

  10. Epidemic spreading on dual-structure networks with mobile agents

    Science.gov (United States)

    Yao, Yiyang; Zhou, Yinzuo

    2017-02-01

    The rapid development of modern society continually transforms the social structure which leads to an increasingly distinct dual structure of higher population density in urban areas and lower density in rural areas. Such structure may induce distinctive spreading behavior of epidemics which does not happen in a single type structure. In this paper, we study the epidemic spreading of mobile agents on dual structure networks based on SIRS model. First, beyond the well known epidemic threshold for generic epidemic model that when the infection rate is below the threshold a pertinent infectious disease will die out, we find the other epidemic threshold which appears when the infection rate of a disease is relatively high. This feature of two thresholds for the SIRS model may lead to the elimination of infectious disease when social network has either high population density or low population density. Interestingly, however, we find that when a high density area is connected to a low density may cause persistent spreading of the infectious disease, even though the same disease will die out when it spreads in each single area. This phenomenon indicates the critical role of the connection between the two areas which could radically change the behavior of spreading dynamics. Our findings, therefore, provide new understanding of epidemiology pertinent to the characteristic modern social structure and have potential to develop controlling strategies accordingly.

  11. Epidemic spread over networks with agent awareness and social distancing

    KAUST Repository

    Paarporn, Keith

    2016-04-20

    We study an SIS epidemic model over an arbitrary connected network topology when the agents receive personalized information about the current epidemic state. The agents utilize their available information to either reduce interactions with their neighbors (social distancing) when they believe the epidemic is currently prevalent or resume normal interactions when they believe there is low risk of becoming infected. The information is a weighted combination of three sources: 1) the average states of nodes in contact neighborhoods 2) the average states of nodes in an information network 3) a global broadcast of the average epidemic state of the network. A 2n-state Markov Chain is first considered to model the disease dynamics with awareness, from which a mean-field discrete-time n-state dynamical system is derived, where each state corresponds to an agent\\'s probability of being infected. The nonlinear model is a lower bound of its linearized version about the origin. Hence, global stability of the origin (the diseasefree equilibrium) in the linear model implies global stability in the nonlinear model. When the origin is not stable, we show the existence of a nontrivial fixed point in the awareness model, which obeys a strict partial order in relation to the nontrivial fixed point of the dynamics without distancing. In simulations, we define two performance metrics to understand the effectiveness agent awareness has in reducing the spread of an epidemic. © 2015 IEEE.

  12. Reconstructing the AIDS epidemic among injection drug users in Brazil.

    Science.gov (United States)

    Hacker, Mariana A; Leite, Iuri C; Renton, Adrian; Torres, Tania Guillén de; Gracie, Renata; Bastos, Francisco I

    2006-04-01

    The HIV/AIDS epidemic among injection drug users (IDUs) in Brazil has been unique in terms of temporal and geographical contrasts. This analysis explores these contrasts through the use of multilevel modeling. Standardized AIDS incidence rates among IDUs for Brazilian municipalities (1986-2000) were used as the dependent variable, with a set of social indicators as independent variables (covariates). In some States of the North/Northeast, the epidemic among IDUs has been incipient. The São Paulo epidemic extended to reach a network of municipalities, most of which located far from the capital. More recently, on a smaller scale, a similar extension has been observed in the southernmost States of the country. Both "number of physicians per inhabitant" and "standard distance to the State capital" were found to be associated with AIDS incidence. AIDS cases among IDUs appeared to cluster in wealthier, more developed municipalities. The relative weight of such extensive dissemination in key, heavily populated States prevails in the Brazilian IDU epidemic, defining a central-western-southeastern strip of wealthier middle-sized municipalities and more recently a southern strip of municipalities deeply affected by the epidemic in this population.

  13. Disease-induced resource constraints can trigger explosive epidemics

    Science.gov (United States)

    Böttcher, L.; Woolley-Meza, O.; Araújo, N. A. M.; Herrmann, H. J.; Helbing, D.

    2015-11-01

    Advances in mathematical epidemiology have led to a better understanding of the risks posed by epidemic spreading and informed strategies to contain disease spread. However, a challenge that has been overlooked is that, as a disease becomes more prevalent, it can limit the availability of the capital needed to effectively treat those who have fallen ill. Here we use a simple mathematical model to gain insight into the dynamics of an epidemic when the recovery of sick individuals depends on the availability of healing resources that are generated by the healthy population. We find that epidemics spiral out of control into “explosive” spread if the cost of recovery is above a critical cost. This can occur even when the disease would die out without the resource constraint. The onset of explosive epidemics is very sudden, exhibiting a discontinuous transition under very general assumptions. We find analytical expressions for the critical cost and the size of the explosive jump in infection levels in terms of the parameters that characterize the spreading process. Our model and results apply beyond epidemics to contagion dynamics that self-induce constraints on recovery, thereby amplifying the spreading process.

  14. Epidemic Intelligence. Langmuir and the Birth of Disease Surveillance

    Directory of Open Access Journals (Sweden)

    Lyle Fearnley

    2010-12-01

    Full Text Available In the wake of the SARS and influenza epidemics of the past decade, one public health solution has become a refrain: surveillance systems for detection of disease outbreaks. This paper is an effort to understand how disease surveillance for outbreak detection gained such paramount rationality in contemporary public health. The epidemiologist Alexander Langmuir is well known as the creator of modern disease surveillance. But less well known is how he imagined disease surveillance as one part of what he called “epidemic intelligence.” Langmuir developed the practice of disease surveillance during an unprecedented moment in which the threat of biological warfare brought civil defense experts and epidemiologists together around a common problem. In this paper, I describe how Langmuir navigated this world, experimenting with new techniques and rationales of epidemic control. Ultimately, I argue, Langmuir′s experiments resulted in a set of techniques and infrastructures – a system of epidemic intelligence – that transformed the epidemic as an object of human art.

  15. Reconstructing the AIDS epidemic among injection drug users in Brazil

    Directory of Open Access Journals (Sweden)

    Mariana A. Hacker

    2006-04-01

    Full Text Available The HIV/AIDS epidemic among injection drug users (IDUs in Brazil has been unique in terms of temporal and geographical contrasts. This analysis explores these contrasts through the use of multilevel modeling. Standardized AIDS incidence rates among IDUs for Brazilian municipalities (1986-2000 were used as the dependent variable, with a set of social indicators as independent variables (covariates. In some States of the North/Northeast, the epidemic among IDUs has been incipient. The São Paulo epidemic extended to reach a network of municipalities, most of which located far from the capital. More recently, on a smaller scale, a similar extension has been observed in the southernmost States of the country. Both "number of physicians per inhabitant" and "standard distance to the State capital" were found to be associated with AIDS incidence. AIDS cases among IDUs appeared to cluster in wealthier, more developed municipalities. The relative weight of such extensive dissemination in key, heavily populated States prevails in the Brazilian IDU epidemic, defining a central-western-southeastern strip of wealthier middle-sized municipalities and more recently a southern strip of municipalities deeply affected by the epidemic in this population.

  16. Unfair Lineups Make Witnesses More Likely to Confuse Innocent and Guilty Suspects.

    Science.gov (United States)

    Colloff, Melissa F; Wade, Kimberley A; Strange, Deryn

    2016-09-01

    Eyewitness-identification studies have focused on the idea that unfair lineups (i.e., ones in which the police suspect stands out) make witnesses more willing to identify the police suspect. We examined whether unfair lineups also influence subjects' ability to distinguish between innocent and guilty suspects and their ability to judge the accuracy of their identification. In a single experiment (N = 8,925), we compared three fair-lineup techniques used by the police with unfair lineups in which we did nothing to prevent distinctive suspects from standing out. Compared with the fair lineups, doing nothing not only increased subjects' willingness to identify the suspect but also markedly impaired subjects' ability to distinguish between innocent and guilty suspects. Accuracy was also reduced at every level of confidence. These results advance theory on witnesses' identification performance and have important practical implications for how police should construct lineups when suspects have distinctive features. © The Author(s) 2016.

  17. [An epidemic risk of yellow fever in Burkina Faso despite a rapid immunisation riposte: role of a multidisciplinary investigation team].

    Science.gov (United States)

    Barennes, H; Baldet, T; Cassel, A-M; Kabiré, C; Kambou, C

    2002-01-01

    On October 8, 1999, one yellow fever (YF) case is confirmed in the South West of Burkina Faso by the Centre Muraz' virology unit. Epidemic extension is suspected as large movements of population are occurring due to troubles in Côte d'Ivoire nearby and as the Aedes vector is endemic in the region. On October 23, the Gaoua's Health Regional Head immunizes 1,000 people around the detected YF case, i.e. 70% of the estimated population and requests an epidemiological investigation. A multidisciplinary team (epidemiologist, entomologist, virologist) from the Centre Muraz, a medical research centre based in Bobo Dioulasso investigate in order to answer the following questions: are there any other or asymptomatic cases of YF? How far is the epidemic risk? Is a paper filter a valuable method for collecting blood samples? What benefit can be gained from a multidisciplinary team? An epidemiological analysis of the patient, a research of asymptomatic or ignored patient is performed (Health Centre registers, interview of the population). This includes the research of people missing the immunisation campaign. Blood samples are collected through 5 ml EDTA glass tubes or through filter paper in order to measure immunoglobuline M. A classical entomological prospecting completes the investigation. Two possible cases are suspected in the patient's home. History of the patient's is in agreement with a local contamination. In the village 110 people missed the immunisation campaign and samples were collected in 58 people including 26 children. Among them, four (15.3%) were positive with immunoglobuline M, while there were none in the adults. Aedes Luteocephalus, a potential vector is collected through night-captures but is absent of home-water collection. Paper filter assays shows a 100% concordance with classical method. The team could determine the persistency of a yellow fever epidemic risk in the region despite a rapid and adequate immunisation riposte. Due to iterative sporadic

  18. [Observations on the 1348 plague epidemic. Measures taken to combat its tragic effects and avoid epidemic recrudescence].

    Science.gov (United States)

    Sabbatani, Sergio

    2003-03-01

    When the "Black Death" swept through Europe from southern France in 1348, in the short space of two years the Europeans were hit by one of the most serious epidemics ever recorded in human history. Yersinia pestis reached Europe by sea, its contamination propagated by the Genoese ships coming from the Crimean port of Jaffa. For the first time the world experienced microbiological unification: East and West were equally involved in the tragedy that spread, and no town remained unscathed during the various epidemic waves which succeeded one another in the following three centuries. The authors of this article describe how and why the epidemic spread, as well as the factors that led to the swift, and often fatal, involment of millions of Europeans. The second part of the article deals with the measures taken by the healthcare authorities of European towns and countries in order to halt the proliferation of the disease. According to the data and observations by authoritative authors, selected among the many who studied the disease that from the 14th century spread like a scourge throughout the known world at the time, the epidemic could have been even more serious, in terms of mortality and morbidity, without the disciplinary and provisional health measures taken. The experience gained in Italy and all over Europe at the time proved useful not only to better manage the epidemics which cyclically broke out, but also to efficiently combat the cholera epidemics of the 19th century. With the 14th century plague epidemic, the Europeans and their political and administrative representatives may well have realized for the very first time that contamination could be combatted by adopting a set of rational, scientific norms - although in practice such rules were mostly inspired by misguided scientific theories. Humankind was no longer alone. A new society was emerging, one that was not going to passively accept the more or less mysterious ways of a superior being of fate. The

  19. A suspected case of lymphogranuloma venereum (LGV) suggests underdiagnosed LGV infection among Slovenian men who have sex with men.

    Science.gov (United States)

    Mlakar, Boštjan; Ramšak, Ana

    2016-06-01

    Lymphogranuloma venereum (LGV) is sexually transmitted infection caused by serovars of Chlamydia trachomatis, mostly seen among HIV-positive men who have sex with men. The first three reports of possible LGV in Slovenia were from April to June 2015, followed by a confirmed case of LGV in August 2015. We present the case of an HIV-positive MSM that presented with an anorectal abscess, discharge, lymphadenopathy, and unusual perianal plaque. Gonococcal proctitis was assumed and he received empirical antibiotic treatment, after which only intermittent improvement occurred. After a positive test result for chlamydial infection, but without a response to azithromycin treatment, LGV was suspected. Treatment according to the guidelines was introduced. When doxycycline therapy started, rapid improvement was observed, and it was therefore assumed that the LGV infection had been successfully treated. Two similar cases with an unusual anorectal presentation and an excellent response to antibiotic therapy for LGV were observed at the same center shortly thereafter. While pointing out possible delays and limitations in diagnostic procedures at self-pay facilities, the need for better access to high quality STI management in public and in private services is emphasized. Enhanced surveillance and testing guidelines could reveal a hidden LGV epidemic among MSM in Slovenia.

  20. Obesity epidemic in Brazil and Argentina: a public health concern.

    Science.gov (United States)

    Arbex, Alberto K; Rocha, Denise R T W; Aizenberg, Marisa; Ciruzzi, Maria S

    2014-06-01

    The obesity epidemic is rapidly advancing in South America, leading to inevitable health consequences. Argentinian and Brazilian health policies try to become adapted to the new economic and social framework that follows from this epidemic. It is in incipient and ineffective control so far since the prevalence of obesity was not restrained. The Argentine national legislation is more advanced, through the so-called "Ley de Obesidad." In Brazil, there are numerous local initiatives but still not a comprehensive law. National policies relating to decisions regarding obesity are discussed in this paper. Trends in decisions issued in higher courts of Argentina (Supreme Court of Justice of the Nation--CSJN) and Brazil (Supreme Court of Justice--STF), in the last 15 years, seek to clarify the approach of each country and court's resolutions. Marked differences were found in their positions. Finally, legal and health solutions to this obesity epidemic are proposed.

  1. Horizontal antimicrobial resistance transfer drives epidemics of multiple Shigella species.

    Science.gov (United States)

    Baker, Kate S; Dallman, Timothy J; Field, Nigel; Childs, Tristan; Mitchell, Holly; Day, Martin; Weill, François-Xavier; Lefèvre, Sophie; Tourdjman, Mathieu; Hughes, Gwenda; Jenkins, Claire; Thomson, Nicholas

    2018-04-13

    Horizontal gene transfer has played a role in developing the global public health crisis of antimicrobial resistance (AMR). However, the dynamics of AMR transfer through bacterial populations and its direct impact on human disease is poorly elucidated. Here, we study parallel epidemic emergences of multiple Shigella species, a priority AMR organism, in men who have sex with men to gain insight into AMR emergence and spread. Using genomic epidemiology, we show that repeated horizontal transfer of a single AMR plasmid among Shigella enhanced existing and facilitated new epidemics. These epidemic patterns contrasted with slighter, slower increases in disease caused by organisms with vertically inherited (chromosomally encoded) AMR. This demonstrates that horizontal transfer of AMR directly affects epidemiological outcomes of globally important AMR pathogens and highlights the need for integration of genomic analyses into all areas of AMR research, surveillance and management.

  2. Steady States in SIRS Epidemical Model of Mobile Individuals

    International Nuclear Information System (INIS)

    Zhang Duanming; He Minhua; Yu Xiaoling; Pan Guijun; Sun Hongzhang; Su Xiangying; Sun Fan; Yin Yanping; Li Rui; Liu Dan

    2006-01-01

    We consider an epidemical model within socially interacting mobile individuals to study the behaviors of steady states of epidemic propagation in 2D networks. Using mean-field approximation and large scale simulations, we recover the usual epidemic behavior with critical thresholds δ c and p c below which infectious disease dies out. For the population density δ far above δ c , it is found that there is linear relationship between contact rate λ and the population density δ in the main. At the same time, the result obtained from mean-field approximation is compared with our numerical result, and it is found that these two results are similar by and large but not completely the same.

  3. Steady States in SIRS Epidemical Model of Mobile Individuals

    Institute of Scientific and Technical Information of China (English)

    ZHANG Duan-Ming; LIU Dan; HE Min-Hua; YU Xiao-Ling; PAN Gui-Jun; SUN Hong-Zhang; SU Xiang-Ying; SUN Fan; YIN Yan-Ping; LI Rui

    2006-01-01

    We consider an epidemical model within socially interacting mobile individuals to study the behaviors of steady statesof epidemic propagation in 2D networks. Using mean-field approximation and large scale simulations, we recover the usual epidemic behavior with critical thresholds δc and pc below which infectious disease dies out. For the population density δ far above δc, it is found that there is linear relationship between contact rate λ and the population density δ in the main. At the same time, the result obtained from mean-field approximation is compared with our numerical result, and it is found that these two results are similar by and large but not completely the same.

  4. Epidemic spreading on contact networks with adaptive weights.

    Science.gov (United States)

    Zhu, Guanghu; Chen, Guanrong; Xu, Xin-Jian; Fu, Xinchu

    2013-01-21

    The heterogeneous patterns of interactions within a population are often described by contact networks, but the variety and adaptivity of contact strengths are usually ignored. This paper proposes a modified epidemic SIS model with a birth-death process and nonlinear infectivity on an adaptive and weighted contact network. The links' weights, named as 'adaptive weights', which indicate the intimacy or familiarity between two connected individuals, will reduce as the disease develops. Through mathematical and numerical analyses, conditions are established for population extermination, disease extinction and infection persistence. Particularly, it is found that the fixed weights setting can trigger the epidemic incidence, and that the adaptivity of weights cannot change the epidemic threshold but it can accelerate the disease decay and lower the endemic level. Finally, some corresponding control measures are suggested. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. The paralytic poliomyelitis epidemic of 1978 in Jordan: epidemiological implications

    Science.gov (United States)

    Khuri-Bulos, Najwa; Melnick, Joseph L.; Hatch, Milford H.; Dawod, Saleh T.

    1984-01-01

    Poliomyelitis is endemic in Jordan, but until 1978 there were no epidemics. In that year, 66 children were admitted to the Jordan University Hospital with a paralytic illness, compared with 13 in 1979 and 11 in 1980. The epidemic reached a peak in the summer and fall of 1978. While 54% of the patients had not received any vaccine, 19% had received 3 doses of oral poliovaccine; 82% of the cases were in children less than 2 years of age, and all belonged to the lower socioeconomic group. There were 28 deaths with complications of the disease. Poliovirus was isolated from 10 out of 14 rectal swab samples examined (9 with poliovirus 1, 1 with poliovirus 2), and from 4 out of 13 throat specimens from the same patients. It is concluded that as a result of improving living standards in Jordan and neighbouring countries, more epidemics may occur unless immunization efforts against poliomyelitis are intensified. PMID:6609022

  6. Global Changes in Food Supply and the Obesity Epidemic.

    Science.gov (United States)

    Zobel, Emilie H; Hansen, Tine W; Rossing, Peter; von Scholten, Bernt Johan

    2016-12-01

    We explore how a global shift in the food system caused by global economic growth, increase in available food per capita and in food processing is a driver of the obesity epidemic. Economic development in most areas of the world has resulted in increased purchasing power and available per capita food. Supermarkets and a growing fast-food industry have transformed our dietary pattern. Ultra-processed food rich on sugars and saturated fat is now the major source of energy in most countries. The shift in food supply is considered a major driver of the obesity epidemic and the increasing prevalence of accompanying complications, such as type 2 diabetes, cardiovascular disease and cancer. However, the global shift might also have direct effects on the increase in type 2 diabetes, cardiovascular disease and cancer, independently of overweight and obesity. The shift in the food supply is a major driver of the obesity epidemic.

  7. Association of Drought with Typhus Epidemics in Central Mexico

    Science.gov (United States)

    Acuna-Soto, R.; Stahle, D.; Villanueva Diaz, J.; Therrell, M.

    2007-05-01

    Typhus is an acute infectious disease caused by the bacteria Rickettsia prowazekii, which is transmitted among humans by the body lice (Pediculus humanus corporis). The disease is highly contagious and transmission is favored in populations living in crowded conditions. Under these circumstances, typhus transmission is facilitated by factors that favor the colonization and proliferation of body lice such as absence of personal hygiene and wearing the same clothes for long periods of time. Historically, periods of war and famine were associated with devastating epidemics with high mortality rates in many parts of the world. Central Mexico has a long record of typhus epidemics. In this region, at > 2000 meters above sea level, the disease was endemic and occurred with a seasonal pattern in winter, with occasional large epidemics. Recently, we completed a chronology of epidemics in Mexico. A total of 22 well-defined major typhus epidemics were identified between 1650 and 1920. All of them caused periods of increased mortality that lasted 2 - 4 years (more than one standard deviation from the previous ten year period). The record of typhus epidemics was evaluated against the tree-ring record of Cuauhtmoc La Fragua, Puebla. This chronology, based on Douglas fir, has demonstrated to be a faithful record of precipitation in central Mexico. The results indicate that a statistically significant drought (t test, p first year of all 22 large outbreaks of typhus in recent Mexican history. No distinction is made between times of peace and war. This indicates that drought alone was capable of inducing the social conditions for increased transmission of typhus in pre-industrial central Mexico.

  8. Using Internet Artifacts to Profile a Child Pornography Suspect

    Directory of Open Access Journals (Sweden)

    Marcus K. Rogers

    2014-03-01

    Full Text Available Digital evidence plays a crucial role in child pornography investigations. However, in the following case study, the authors argue that the behavioral analysis or “profiling” of digital evidence can also play a vital role in child pornography investigations. The following case study assessed the Internet Browsing History (Internet Explorer Bookmarks, Mozilla Bookmarks, and Mozilla History from a suspected child pornography user’s computer. The suspect in this case claimed to be conducting an ad hoc law enforcement investigation. After the URLs were classified (Neutral; Adult Porn; Child Porn; Adult Dating sites; Pictures from Social Networking Profiles; Chat Sessions; Bestiality; Data Cleaning; Gay Porn, the Internet history files were statistically analyzed to determine prevalence and trends in Internet browsing. First, a frequency analysis was used to determine a baseline of online behavior. Results showed 54% (n = 3205 of the URLs were classified as “neutral” and 38.8% (n = 2265 of the URLs were classified as a porn website. Only 10.8% of the URLs were classified as child pornography websites. However when the IE history file was analyzed by visit, or “hit,” count, the Pictures/Profiles (31.5% category had the highest visit count followed by Neutral (19.3%, Gay Porn (17%, and Child Porn (16.6%. When comparing the frequency of URLs to the Hit Count for each pornography type, it was noted that the accused was accessing gay porn, child porn, chat rooms, and picture profiles (i.e., from Facebook more often than adult porn and neutral websites. The authors concluded that the suspect in this case was in fact a child pornography user and not an ad hoc investigator, and the findings from the behavioral analysis were admitted as evidence in the sentencing hearing for this case. The authors believe this case study illustrates the ability to conduct a behavioral analysis of digital evidence. More work is required to further validate the

  9. Suppressing traffic-driven epidemic spreading by use of the efficient routing protocol

    International Nuclear Information System (INIS)

    Yang, Han-Xin; Wu, Zhi-Xi

    2014-01-01

    Despite extensive work on the interplay between traffic dynamics and epidemic spreading, the control of epidemic spreading by routing strategies has not received adequate attention. In this paper, we study the impact of an efficient routing protocol on epidemic spreading. In the case of infinite node-delivery capacity, where the traffic is free of congestion, we find that that there exist optimal values of routing parameter, leading to the maximal epidemic threshold. This means that epidemic spreading can be effectively controlled by fine tuning the routing scheme. Moreover, we find that an increase in the average network connectivity and the emergence of traffic congestion can suppress the epidemic outbreak. (paper)

  10. Stable intergenerational associations of childhood overweight during the development of the obesity epidemic

    DEFF Research Database (Denmark)

    Ajslev, Teresa A; Ängquist, Lars; Silventoinen, Karri

    2015-01-01

    OBJECTIVE: The obesity epidemic may have developed as a response to the obesogenic environment among the genetically predisposed. This investigation examined whether the intergenerational resemblances in childhood overweight changed across the development of the obesity epidemic in groups of chil......: Parent-child resemblance in childhood overweight showed small changes during the development of the obesity epidemic, suggesting that the obesogenic environment inducing the epidemic in Denmark influenced children irrespective of their familial predisposition.......OBJECTIVE: The obesity epidemic may have developed as a response to the obesogenic environment among the genetically predisposed. This investigation examined whether the intergenerational resemblances in childhood overweight changed across the development of the obesity epidemic in groups...

  11. Predicting and controlling infectious disease epidemics using temporal networks.

    Science.gov (United States)

    Masuda, Naoki; Holme, Petter

    2013-01-01

    Infectious diseases can be considered to spread over social networks of people or animals. Mainly owing to the development of data recording and analysis techniques, an increasing amount of social contact data with time stamps has been collected in the last decade. Such temporal data capture the dynamics of social networks on a timescale relevant to epidemic spreading and can potentially lead to better ways to analyze, forecast, and prevent epidemics. However, they also call for extended analysis tools for network epidemiology, which has, to date, mostly viewed networks as static entities. We review recent results of network epidemiology for such temporal network data and discuss future developments.

  12. Ebola epidemic of 2014-2015: unresolved ethical issues.

    Science.gov (United States)

    Garbuglia, Anna Rosa

    2016-01-01

    Some ethical aspects of the management of the Ebola epidemic in Guinea, Liberia and Sierra Leone which started in January 2014, have been questionable. First, as regards the prevention of the spread of the virus, the necessary epidemiological investigations on the origin of the infection were not carried out adequately and this did not help to curb the spread of the disease. A disparity has been observed between the western and African countries' access to the treatment of patients; this infringes on the principle of equality. This paper also focuses on how the Global Public Goods for Health principle was not fully respected in the management of the epidemic.

  13. Epidemic Increase in Methicillin-resistant Staphylococcus aureus in Copenhagen

    DEFF Research Database (Denmark)

    Westh, Henrik; Boye, Kit; Bartels, Mette Damkjær

    2006-01-01

    INTRODUCTION: We have found an epidemic increase in methicillin-resistant Staphylococcus aureus (MRSA) in Copenhagen. The increase has a complex background and involves hospitals, nursing homes and persons nursed in their own home. MATERIAL AND METHODS: We found 33 MRSA patients in 2003 and 121...... in 2004. All isolates have been spa-typed and epidemiologic information collected. RESULTS: The number of MRSA cases has a doubling time of about six months. The epidemic has been caused by many different MRSA types and 31 staphylococcus protein A genotypes (spa types). MRSA has caused several hospital...

  14. Reiter′s Disease - Clinical Profile of Epidemic Form

    Directory of Open Access Journals (Sweden)

    H S Girgia

    1980-01-01

    Full Text Available Absence of urethritis need not exclude the possiblity of Reiter′s disease in young males where conjunctivitis and polyarthritis are cardinal features. Appearance of cutaneous lesion early in the course of the disease heralds a poor prognosis specially in the rare epidemic form of the disease. Two cases of Reiter′s disease are reported. Both belonged to the dysentric type of the disease; sometimes ref to as the epidemic form. Relatively high dose of steroids necessary to control symptoms.

  15. Ebola Virus Epidemic in West Africa and Beyond

    Directory of Open Access Journals (Sweden)

    Oscar G Gómez-Duarte

    2014-10-01

    Full Text Available Is there a reason to fear that an Ebola outbreak may strike Latin America? The fear may not be unreasonable taking into account the history of epidemics that have affected the American continent since colonization times in 1492. Old World small pox epidemics spread and killed millions of Native Americans north and south from the equator. Imported West Nile virus infections reported in New York in 1999 dramatically spread East to West of the United States. Most recently, Chikungunya virus arrived to Central America in 2013 and has already infected close to 1 million people in Mexico, Central American countries, Brazil, Colombia, Ecuador, Guyanas, Paraguay, and Venezuela.

  16. Random migration processes between two stochastic epidemic centers.

    Science.gov (United States)

    Sazonov, Igor; Kelbert, Mark; Gravenor, Michael B

    2016-04-01

    We consider the epidemic dynamics in stochastic interacting population centers coupled by random migration. Both the epidemic and the migration processes are modeled by Markov chains. We derive explicit formulae for the probability distribution of the migration process, and explore the dependence of outbreak patterns on initial parameters, population sizes and coupling parameters, using analytical and numerical methods. We show the importance of considering the movement of resident and visitor individuals separately. The mean field approximation for a general migration process is derived and an approximate method that allows the computation of statistical moments for networks with highly populated centers is proposed and tested numerically. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Network Performance Improvement under Epidemic Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Ruepp, Sarah Renée

    2013-01-01

    In this paper we investigate epidemic failure spreading in large- scale GMPLS-controlled transport networks. By evaluating the effect of the epidemic failure spreading on the network, we design several strategies for cost-effective network performance improvement via differentiated repair times....... First we identify the most vulnerable and the most strategic nodes in the network. Then, via extensive simulations we show that strategic placement of resources for improved failure recovery has better performance than randomly assigning lower repair times among the network nodes. Our OPNET simulation...... model can be used during the network planning process for facilitating cost- effective network survivability design....

  18. The effect of heterogeneity on invasion in spatial epidemics

    DEFF Research Database (Denmark)

    Neri, Franco M; Bates, Anne; Füchtbauer, Winnie Sophie

    2011-01-01

    Heterogeneity in host populations is an important factor affecting the ability of a pathogen to invade, yet the quantitative investigation of its effects on epidemic spread is still an open problem. In this paper, we test recent theoretical results, which extend the established “percolation...... paradigm” to the spread of a pathogen in discrete heterogeneous host populations. In particular, we test the hypothesis that the probability of epidemic invasion decreases when host heterogeneity is increased. We use replicated experimental microcosms, in which the ubiquitous pathogenic fungus Rhizoctonia...

  19. Stochastic epidemic-type model with enhanced connectivity: exact solution

    International Nuclear Information System (INIS)

    Williams, H T; Mazilu, I; Mazilu, D A

    2012-01-01

    We present an exact analytical solution to a one-dimensional model of the susceptible–infected–recovered (SIR) epidemic type, with infection rates dependent on nearest-neighbor occupations. We use a quantum mechanical approach, transforming the master equation via a quantum spin operator formulation. We calculate exactly the time-dependent density of infected, recovered and susceptible populations for random initial conditions. Our results compare well with those of previous work, validating the model as a useful tool for additional and extended studies in this important area. Our model also provides exact solutions for the n-point correlation functions, and can be extended to more complex epidemic-type models

  20. Distemper in raccoons and foxes suspected of having rabies

    Science.gov (United States)

    Habermann, R.T.; Herman, C.M.; Williams, F.P.

    1958-01-01

    1) Twenty-one raccoons and 3 red foxes were collected from areas where suspected rabies occurred. All were found to be nonrabid. 2) Distemper was diagnosed in 14 of the 21 raccoons by demonstrating intracytoplasmic and intranuclear inclusions in the brain and visceral tissues. Two of the 3 foxes were considered to have distemper; the clinical signs were typical and mouse inoculation tests were negative for rabies. 3) Deaths of the other 7 raccoons were attributed to: leishmaniasis 1, gastritis 1, bronchopneumonia 1, parasitism 2, car injury 1; 1 showed no significant lesions. The death of 1 fox was attributed to parasitism. 4) Distemper may be a frequent cause of death in raccoons and foxes, in epizootics which simulate rabies.

  1. Diagnosis of suspected venous thromboembolic disease in pregnancy

    International Nuclear Information System (INIS)

    Scarsbrook, A.F.; Evans, A.L.; Owen, A.R.; Gleeson, F.V.

    2006-01-01

    Venous thromboembolic disease is a leading cause of maternal mortality during pregnancy. Early and accurate radiological diagnosis is essential as anticoagulation is not without risk and clinical diagnosis is unreliable. Although the disorder is potentially treatable, unnecessary treatment should be avoided. Most of the diagnostic imaging techniques involve ionizing radiation which exposes both the mother and fetus to finite radiation risks. There is a relative lack of evidence in the literature to guide clinicians and radiologists on the most appropriate method of assessing this group of patients. This article will review the role of imaging of suspected venous thromboembolic disease in pregnant patients, highlight contentious issues such as radiation risk, intravenous contrast use in pregnancy and discuss the published guidelines, as well as suggesting an appropriate imaging algorithm based on the available evidence

  2. Strength training for a child with suspected developmental coordination disorder.

    Science.gov (United States)

    Menz, Stacy M; Hatten, Kristin; Grant-Beuttler, Marybeth

    2013-01-01

    Children with developmental coordination disorder (DCD) demonstrate difficulty with feedforward motor control and use varied compensatory strategies. To examine gross motor function changes following strength training in a child with motor control difficulties. A girl aged 6 years 11 months, with apraxia and hypotonia, and demonstrating motor delays consistent with DCD. Twenty-four strength training sessions were completed using a universal exercise unit. Postintervention scores significantly improved on the Bruininks-Oseretsky test of motor proficiency, second edition, and the Canadian occupational performance measure scores and raised the developmental coordination disorder questionnaire, revised 2007, scores above the range where DCD is suspected. Nonsignificant changes in strength were observed. Improved function and significant gains in manual coordination were observed following blocked practice of isolated, simple joint movements during strength training. Improved motor skills may be because of effective use of feedforward control and improved stabilization. Strength training does not rehearse skills using momentum, explaining nonsignificant changes in locomotor or locomotion areas.

  3. Management of suspected monogenic lung fibrosis in a specialised centre

    Directory of Open Access Journals (Sweden)

    Raphael Borie

    2017-04-01

    Full Text Available At least 10% of patients with interstitial lung disease present monogenic lung fibrosis suspected on familial aggregation of pulmonary fibrosis, specific syndromes or early age of diagnosis. Approximately 25% of families have an identified mutation in genes mostly involved in telomere homeostasis, and more rarely in surfactant homeostasis. Beyond pathophysiological knowledge, detection of these mutations has practical consequence for patients. For instance, mutations involved in telomere homeostasis are associated with haematological complications after lung transplantation and may require adapted immunosuppression. Moreover, relatives may benefit from a clinical and genetic evaluation that should be specifically managed. The field of genetics of pulmonary fibrosis has made great progress in the last 10 years, raising specific problems that should be addressed by a specialised team.

  4. Bile acid aspiration in suspected ventilator-associated pneumonia.

    Science.gov (United States)

    Wu, Yu-Chung; Hsu, Po-Kuei; Su, Kang-Cheng; Liu, Lung-Yu; Tsai, Cheng-Chien; Tsai, Shu-Ho; Hsu, Wen-Hu; Lee, Yu-Chin; Perng, Diahn-Warng

    2009-07-01

    The aims of this study were to measure the levels of bile acids in patients with suspected ventilator-associated pneumonia (VAP) and provide a possible pathway for neutrophilic inflammation to explain its proinflammatory effect on the airway. Bile acid levels were measured by spectrophotometric enzymatic assay, and liquid chromatography mass spectrometry was used to quantify the major bile acids. Alveolar cells were grown on modified air-liquid interface culture inserts, and bile acids were then employed to stimulate the cells. Reverse transcriptase polymerase chain reaction and Western blots were used to determine the involved gene expression and protein levels. The mean (+/- SE) concentration of total bile acids in tracheal aspirates was 6.2 +/- 2.1 and 1.1 +/- 0.4 mumol/L/g sputum, respectively, for patients with and without VAP (p VAP group (p aspiration may reduce the intensity of neutrophilic inflammation in intubated and mechanically ventilated patients in the ICU.

  5. [Diagnostic strategy in patients with clinically suspected deep vein thrombosis

    DEFF Research Database (Denmark)

    Mantoni, Margit Yvonne; Kristensen, M.; Brogaard, M.H.

    2008-01-01

    INTRODUCTION: The standard method for diagnosing deep vein thrombosis (DVT) involves determination of D-dimer and ultrasound scanning. In an attempt to reduce the number of ultrasound examinations we have supplemented this with a clinical probability estimate for DVT (DVT-score) over one year....... MATERIALS AND METHODS: A total of 508 consecutive patients presenting in the emergency room with suspected DVT had D-dimer and DVT-score performed. Patients with non-elevated D-dimer and a low or moderate DVT score received no treatment. The remainder had ultrasound scanning from the groin to the popliteal...... patients with normal D-dimer had high DVT-scores, none had DVT, so that the benefit from determining DVT-scores was modest. Ultrasound scanning revealed DVT in 85 out of 397 patients with elevated D-dimer. A repeat examination was performed in 91 patients with persisting symptoms, and disclosed DVT in two...

  6. Suspected seminal vesiculitis in an Asian elephant (Elephas maximus).

    Science.gov (United States)

    Kilburn, Jennifer J; Velguth, Karen E; Backues, Kay A

    2011-09-01

    A 32-year-old male Asian elephant (Elephas maximus) underwent routine transrectal stimulation for semen collection as part of an artificial insemination program. The procedure consisted of a preinsemination semen collection followed by two consecutive days of semen collections for artificial insemination. The second day's sample contained large numbers of inflammatory cells, intracellular bacteria, and phagocytized sperm. Semen was submitted for culture and sensitivity. Culture revealed Acinetobacter lwoffii, Staphylococcus intermedius, Kocuria roseus, and an unidentified gram-positive organism. Empirical antibiotic therapy with trimethoprim sulfa was initiated and then changed to enrofloxacin based on sensitivity panel results for a total of 28 days of treatment. Diagnostic semen collections were performed during treatment and 2 wk posttreatment to determine the success of therapy. Posttreatment collections revealed resolution of the inflammation. The origin of the infection was suspected to be the seminal vesicles.

  7. Unenhanced MR Imaging in adults with clinically suspected acute appendicitis

    DEFF Research Database (Denmark)

    Chabanova, Elizaveta; Balslev, Ingegerd; Achiam, Michael

    2011-01-01

    PURPOSE: The purpose of the study was to evaluate unenhanced Magnetic Resonance Imaging (MRI) for the diagnosis of appendicitis or another surgery-requiring condition in an adult population scheduled for emergency appendectomy based on a clinical diagnosis of suspected acute appendicitis. MATERIALS...... radiologists and one surgeon independent of each other and compared with surgical and pathological records. RESULTS: According to the surgical and histopathological findings 30 of 48 patients (63%) had acute appendicitis. Of the remaining 18 patients, 4 patients had no reasons for the clinical symptoms and 14...... patients had other pathology. For the three reviewers the performance of MRI in the diagnosis of acute appendicitis showed the following sensitivity, specificity and accuracy ranges: 83-93%, 50-83% and 77-83%. Moderate (kappa=0.51) and fair (kappa=0.31) interobserver agreements in the MR diagnosis of acute...

  8. Optical spectroscopy of known and suspected Herbig-Haro objects

    International Nuclear Information System (INIS)

    Cohen, M.; Fuller, G.A.; California Univ., Berkeley)

    1985-01-01

    Optical spectra of a number of suspected Herbig-Haro objects are presented. From these, the nature of these nebulosities are determined. Several of the nebulae are of very high density, perhaps due to their extreme youth. Extinctions measured toward DG Tau HH and the L1551 IRS 5 optical jet are in each case substantially less than the stellar values. It is suggested that this phenomenon reflects the existence of appreciably thick circumstellar dust disks around these, and two additional, exciting stars. Shock model diagnostics suggest that the emission lines in these Herbig-Haro nebulae arise in modest velocity shocks with sizable preshock densities in several cases. Radial velocities enable lower limits to be placed on the mass loss rates of those stars that have been detected in the radio continuum. 39 references

  9. Investigating suspected acute pulmonary embolism - what are hospital clinicians thinking?

    International Nuclear Information System (INIS)

    McQueen, A.S.; Worthy, S.; Keir, M.J.

    2008-01-01

    Aims: To assess local clinical knowledge of the appropriate investigation of suspected acute pulmonary embolism (PE) and this compare with the 2003 British Thoracic Society (BTS) guidelines as a national reference standard. Methods: A clinical questionnaire was produced based on the BTS guidelines. One hundred and eight-six participants completed the questionnaires at educational sessions for clinicians of all grades, within a single NHS Trust. The level of experience amongst participants ranged from final year medical students to consultant physicians. Results: The clinicians were divided into four groups based on seniority: Pre-registration, Junior, Middle, and Senior. Forty-six point eight percent of all the clinicians correctly identified three major risk factors for PE and 25.8% recognized the definition of the recommended clinical probability score from two alternatives. Statements regarding the sensitivity of isotope lung imaging and computed tomography pulmonary angiography (CTPA) received correct responses from 41.4 and 43% of participants, respectively, whilst 81.2% recognized that an indeterminate ventilation-perfusion scintigraphy (V/Q) study requires further imaging. The majority of clinicians correctly answered three clinical scenario questions regarding use of D-dimers and imaging (78, 85, and 57.5%). There was no statistically significant difference between the four groups for any of the eight questions. Conclusions: The recommended clinical probability score was unfamiliar to all four groups of clinicians in the present study, and the majority of doctors did not agree that a negative CTPA or isotope lung scintigraphy reliably excluded PE. However, questions based on clinical scenarios received considerably higher rates of correct responses. The results indicate that various aspects of the national guidelines on suspected acute pulmonary embolism are unfamiliar to many UK hospital clinicians. Further research is needed to identify methods to improve

  10. The impact of ultrasound in suspected acute appendicitis

    International Nuclear Information System (INIS)

    Gracey, D.; McClure, M.J.

    2007-01-01

    Aims: To evaluate prospectively the impact of an appendix ultrasound (US) service on the clinical management of patients presenting with suspected acute appendicitis. Materials and methods: The referring clinician completed a proforma for patients presenting with suspected acute appendicitis. Two visual analogue scales assessed clinical suspicion before and after knowledge of laboratory results. The clinician also indicated if they intended to operate had US been unavailable. During a 3-year period, 327 patients were examined by graded-compression US and diagnosed 'positive' or 'negative' for acute appendicitis. Findings were correlated with histopathology results. The referring clinician completed a retrospective audit questionnaire to assess user satisfaction. Results: Clinical suspicion was altered by knowledge of laboratory results. The decision to operate if US had been unavailable, was 'yes' in 70 cases (group A), 'no' in 231 (group B), and incomplete in 26 (group C). In group A, 31 patients (44.3%) had a negative US and 25 avoided surgery. US identified 39 cases of appendicitis and 37 appendicectomies confirmed appendicitis in 34 cases. In group B, 72 (31.2%) patients had a positive US and 66 appendicectomies confirmed 51 cases of appendicitis. The sensitivity of US was 94.7% in group A, 93.3% in group B and 93.8% overall. Specificity was 90.6% in group A, 91.2% in group B and 91.3% overall. US findings were contrary to intended surgical management in 103 cases. Management was altered in 97 cases (32.2%), with a positive outcome in 85 (28.2%). The referrers found US of appendix very useful in planning appropriate management. Conclusion: US of the appendix increases diagnostic accuracy, alters management and is more sensitive and specific than clinical impression, either alone, or in conjunction with laboratory results

  11. Results of photorefractive keratectomy in keratoconus suspects at 4 years.

    Science.gov (United States)

    Bilgihan, K; Ozdek, S C; Konuk, O; Akata, F; Hasanreisoglu, B

    2000-01-01

    We studied the long-term results of photorefractive keratectomy (PRK) in keratoconus suspects detected by videokeratography (TMS). Bilateral inferior corneal steepening was detected in 6 candidates for PRK presenting with moderate myopia or astigmatism. Mean follow-up was 44.5 +/- 4.4 months (range, 38 to 54 mo). Mean spherical equivalent refraction was -5.18 +/- 1.60 D (mean sphere, -4.73 D; mean cyclinder, -0.92 D) which was stable for at least the preceding year. The quantitative measurement of inferior corneal steepening (I-S value) was greater than +1.60 (mean, 1.83 +/- 0.11) in all eyes. An Aesculap Meditec Mel 60 excimer laser was used for the PRK procedures and mean follow-up was 44.5 months. Postoperative pachymetric measurements were also performed in 6 eyes. Postoperative uncorrected visual acuity was 20/20 in 8 eyes (66.6%) and 20/32 or better in all eyes with a mean postoperative spherical equivalent refraction of -0.70 +/- 0.74 D (mean sphere, -0.63 D; mean cyclinder, -0.39 D). Five eyes (41.6%) were within +/- 0.50 D spherical equivalent refraction. Inferior steepening was associated with thinning of the inferior cornea which was statistically significantly thinner than the superior thickness (Student's t-test, P < .05). There were no wound healing problems or any sign that the excimer laser adversely affected the cornea during follow-up. Photorefractive keratectomy seems to be a safe procedure for reducing or eliminating myopia or astigmatism in keratoconus suspect eyes-most probably forme fruste keratoconus-with a stable refraction, but this may be different in eyes with early keratoconus, known to be a progressive disease.

  12. Evaluation of basophil activation test in suspected food hypersensitivity.

    Science.gov (United States)

    Pignatti, Patrizia; Yacoub, Mona-Rita; Testoni, Claudia; Pala, Gianni; Corsetti, Maura; Colombo, Giselda; Meriggi, Antonio; Moscato, Gianna

    2017-07-01

    Food hypersensitivity is characterized by a wide range of symptoms. The relationship between symptoms and food is more frequently suspected than objectively proven. Basophil activation test (BAT) is based on the evaluation of activation markers on blood basophils in vitro stimulated with drugs or allergens. The aim of the study was to evaluate the usefulness of BAT when introduced in the routine work-up of suspected food hypersensitivity. BAT was requested in subjects with food adverse reactions when a discrepancy existed among history and skin prick test (SPT) and/or specific IgE. Data from 150 subjects were analysed using CD63 as basophil activation marker. Thirty controls were evaluated for cut-offs. Immunoblots was performed with the sera of representative subjects positive for BAT and negative for SPT and sIgE. 1,024 BAT were carried out, the agreement (positive/positive and negative/negative) was 78.5% for BAT vs. SPT and 78.3% for BAT vs. IgE. Atopic patients, but not atopic controls, more frequently had a positive BAT than non-atopic patients (P tested food) and both negative sIgE and SPT. Immunoblots revealed the presence of sIgE for the tested foods in representative patients with positive BAT, negative SPT and sIgE. Introduction of BAT in routine of food hypersensitivity, limited to subjects with a discrepancy between history and traditional tests, might be useful particularly when total IgE are low. © 2015 International Clinical Cytometry Society. © 2015 International Clinical Cytometry Society.

  13. Reliability of Examination Findings in Suspected Community-Acquired Pneumonia.

    Science.gov (United States)

    Florin, Todd A; Ambroggio, Lilliam; Brokamp, Cole; Rattan, Mantosh S; Crotty, Eric J; Kachelmeyer, Andrea; Ruddy, Richard M; Shah, Samir S

    2017-09-01

    The authors of national guidelines emphasize the use of history and examination findings to diagnose community-acquired pneumonia (CAP) in outpatient children. Little is known about the interrater reliability of the physical examination in children with suspected CAP. This was a prospective cohort study of children with suspected CAP presenting to a pediatric emergency department from July 2013 to May 2016. Children aged 3 months to 18 years with lower respiratory signs or symptoms who received a chest radiograph were included. We excluded children hospitalized ≤14 days before the study visit and those with a chronic medical condition or aspiration. Two clinicians performed independent examinations and completed identical forms reporting examination findings. Interrater reliability for each finding was reported by using Fleiss' kappa (κ) for categorical variables and intraclass correlation coefficient (ICC) for continuous variables. No examination finding had substantial agreement (κ/ICC > 0.8). Two findings (retractions, wheezing) had moderate to substantial agreement (κ/ICC = 0.6-0.8). Nine findings (abdominal pain, pleuritic pain, nasal flaring, skin color, overall impression, cool extremities, tachypnea, respiratory rate, and crackles/rales) had fair to moderate agreement (κ/ICC = 0.4-0.6). Eight findings (capillary refill time, cough, rhonchi, head bobbing, behavior, grunting, general appearance, and decreased breath sounds) had poor to fair reliability (κ/ICC = 0-0.4). Only 3 examination findings had acceptable agreement, with the lower 95% confidence limit >0.4: wheezing, retractions, and respiratory rate. In this study, we found fair to moderate reliability of many findings used to diagnose CAP. Only 3 findings had acceptable levels of reliability. These findings must be considered in the clinical management and research of pediatric CAP. Copyright © 2017 by the American Academy of Pediatrics.

  14. Cost-effectiveness of routine imaging of suspected appendicitis.

    Science.gov (United States)

    D'Souza, N; Marsden, M; Bottomley, S; Nagarajah, N; Scutt, F; Toh, S

    2018-01-01

    Introduction The misdiagnosis of appendicitis and consequent removal of a normal appendix occurs in one in five patients in the UK. On the contrary, in healthcare systems with routine cross-sectional imaging of suspected appendicitis, the negative appendicectomy rate is around 5%. If we could reduce the rate in the UK to similar numbers, would this be cost effective? This study aimed to calculate the financial impact of negative appendicectomy at the Queen Alexandra Hospital and to explore whether a policy of routine imaging of such patients could reduce hospital costs. Materials and methods We performed a retrospective analysis of all appendicectomies over a 1-year period at our institution. Data were extracted on outcomes including appendix histology, operative time and length of stay to calculate the negative appendicectomy rate and to analyse costs. Results A total of 531 patients over 5 years of age had an appendicectomy. The negative appendicectomy rate was 22% (115/531). The additional financial costs of negative appendicectomy to the hospital during this period were £270,861. Universal imaging of all patients with right iliac fossa pain that could result in a 5% negative appendicectomy rate would cost between £67,200 and £165,600 per year but could save £33,896 (magnetic resonance imaging), £105,896 (computed tomography) or £132,296 (ultrasound) depending on imaging modality used. Conclusions Negative appendicectomy is still too frequent and results in additional financial burden to the health service. Routine imaging of patients with suspected appendicitis would not only reduce the negative appendicectomy rate but could lead to cost savings and a better service for our patients.

  15. Ambulatory Blood Pressure Monitoring in a Cohort of Children Referred with Suspected Hypertension: Characteristics of Children with and without Attention Deficit Hyperactivity Disorder

    Directory of Open Access Journals (Sweden)

    Silviu Grisaru

    2013-01-01

    Full Text Available Childhood hypertension’s increasing prevalence has generally been linked to the obesity epidemic. We observed that a significant proportion of children referred to our pediatric center with documented office hypertension are nonobese and have a history of attention deficit hyperactivity disorder (ADHD. To define the extent of this anecdotal observation, we performed a retrospective analysis of ambulatory blood pressure monitoring (ABPM tests which in our center are routinely performed in newly referred children suspected of hypertension. Twenty-one percent (48 of 227 new referrals had a history of ADHD, and 81% of them were treated with psychostimulant medications at the time of their ABPM test. Children in this group had a significantly lower average BMI z-score compared with the rest of the children (0.18 versus 0.75 and were significantly more likely to have abnormally elevated wake systolic loads on ABPM (38% versus 4%. The overall proportion of children with any abnormality on ABPM was comparable in both groups (46% versus 40%. Conclusion. A significant proportion of children suspected of hypertension have ADHD which may be related to higher wake systolic BP values. The prevalence of hypertension among children with ADHD will have to be determined in prospective studies.

  16. Cultural Practices and the HIV Epidemic in Swaziland: Student\\'s ...

    African Journals Online (AJOL)

    International Journal of Educational Research ... Cultural Practices and the HIV Epidemic in Swaziland: Student\\'s Perspectives and Challenges for School Counsellors ... Keywords: Cultural Practices, HIV Epidemic; Behaviour Change.

  17. A threshold limit theorem for the stochastic logistic epidemic

    OpenAIRE

    Andersson, Håkan; Djehiche, Boualem

    1998-01-01

    The time until extinction for the closed SIS stochastic logistic epidemic model is investigated. We derive the asymptotic distribution for the extinction time as the population grows to infinity, under different initial conditions and for different values of the infection rate.

  18. The threshold of a stochastic SIQS epidemic model

    Science.gov (United States)

    Zhang, Xiao-Bing; Huo, Hai-Feng; Xiang, Hong; Shi, Qihong; Li, Dungang

    2017-09-01

    In this paper, we present the threshold of a stochastic SIQS epidemic model which determines the extinction and persistence of the disease. Furthermore, we find that noise can suppress the disease outbreak. Numerical simulations are also carried out to confirm the analytical results.

  19. Alkaline stabilization of manure slurry inactivates porcine epidemic diarrhea virus

    Science.gov (United States)

    The porcine epidemic diarrhea virus (PEDv) outbreak in North America has substantially impacted swine production since it causes nearly 100% mortality in infected pre-weaned piglets. The PED virus is transmitted via the fecal oral route and manure may remain a source of reinfection; therefore, prop...

  20. How to Estimate Epidemic Risk from Incomplete Contact Diaries Data?

    Science.gov (United States)

    Mastrandrea, Rossana; Barrat, Alain

    2016-06-01

    Social interactions shape the patterns of spreading processes in a population. Techniques such as diaries or proximity sensors allow to collect data about encounters and to build networks of contacts between individuals. The contact networks obtained from these different techniques are however quantitatively different. Here, we first show how these discrepancies affect the prediction of the epidemic risk when these data are fed to numerical models of epidemic spread: low participation rate, under-reporting of contacts and overestimation of contact durations in contact diaries with respect to sensor data determine indeed important differences in the outcomes of the corresponding simulations with for instance an enhanced sensitivity to initial conditions. Most importantly, we investigate if and how information gathered from contact diaries can be used in such simulations in order to yield an accurate description of the epidemic risk, assuming that data from sensors represent the ground truth. The contact networks built from contact sensors and diaries present indeed several structural similarities: this suggests the possibility to construct, using only the contact diary network information, a surrogate contact network such that simulations using this surrogate network give the same estimation of the epidemic risk as simulations using the contact sensor network. We present and compare several methods to build such surrogate data, and show that it is indeed possible to obtain a good agreement between the outcomes of simulations using surrogate and sensor data, as long as the contact diary information is complemented by publicly available data describing the heterogeneity of the durations of human contacts.

  1. Epidemic Processes on Complex Networks : Modelling, Simulation and Algorithms

    NARCIS (Netherlands)

    Van de Bovenkamp, R.

    2015-01-01

    Local interactions on a graph will lead to global dynamic behaviour. In this thesis we focus on two types of dynamic processes on graphs: the Susceptible-Infected-Susceptilbe (SIS) virus spreading model, and gossip style epidemic algorithms. The largest part of this thesis is devoted to the SIS

  2. Simulating individual-based models of epidemics in hierarchical networks

    NARCIS (Netherlands)

    Quax, R.; Bader, D.A.; Sloot, P.M.A.

    2009-01-01

    Current mathematical modeling methods for the spreading of infectious diseases are too simplified and do not scale well. We present the Simulator of Epidemic Evolution in Complex Networks (SEECN), an efficient simulator of detailed individual-based models by parameterizing separate dynamics

  3. Some Empirical Notes on the Epo Epidemic in Professional Cycling

    Science.gov (United States)

    Lodewijkx, Hein F. M.; Brouwer, Bram

    2011-01-01

    The 1990-2010 period in professional cycling is labeled by some as the epo epidemic. Surprisingly, performance enhancement by epo and blood doping is not that clear-cut for endurance athletes, leading to the question whether doping indeed strongly influenced cyclists' performances from the 1990s onwards. We examined the records (1947-2008) of the…

  4. Cardiovascular disease: A Global Epidemic extending into Sub ...

    African Journals Online (AJOL)

    Background: Cardiovascular disease is a global epidemic; the prevalence is currently stable in the developed world but is on a rapid rise in the developing world particularly in Sub-Saharan Africa. It is the commonest cause of morbidity and mortality globally. Its victims are older in the developed world but younger in Africa ...

  5. Perspectives of Spatial Scale in a Wildland Forest Epidemic

    Science.gov (United States)

    W.W. Dillon; S.E. Haas; D.M. Rizzo; R.K. Meentemeyer

    2014-01-01

    The challenge of observing interactions between plant pathogens, their hosts, and environmental heterogeneity across multiple spatial scales commonly limits our ability to understand and manage wildland forest epidemics. Using the forest pathogen Phytophthora ramorum as a case study, we established 20 multiscale field sites to analyze how host-...

  6. [Paediatric emergencies; example of the management of winter epidemics].

    Science.gov (United States)

    Mercier, Jean-Christophe; Bellettre, Xavier; Lejay, Émilie; Desmarest, Marie; Titomanlio, Luigi

    2015-01-01

    Every year, epidemics of viral bronchiolitis and gastroenteritis occur with a significant increase in the number of visits (by a factor 1.8) and hospitalisations that can over-exceed bed capacity leading to transfer sick children to other hospitals. This kind of hospital 'crisis' is not limited to paediatrics, big cities or western nations. It is a worldwide worrying problem. Because our hospital sits in the Northern districts of Paris where a large community of m.ncants lives in poverty, our number of visits is high (mean 250 per day), and winter epidemics further jeopardise the difficult equilibrium achieved between quality management and waiting times. Thus, we have taken various initiatives in terms of organisation of the paediatric emergency department and other wards, including a "fast track" clinic, the opening of beds dedicated to winter epidemics, the institution of a "bed manager" in order to more easily find a bed, and a larger use of home hospitalisations. Furthermore, we created a specific committee which may decide on various indicators of tension whether it is necessary to cancel programmed hospitalisations or surgery.in order to resolve the emergency crisis. This kind of organisation can serve as a model for other hospitals facing winter epidemics crises.

  7. The epidemic of Athens, 430 - 426 BC | Retief | South African ...

    African Journals Online (AJOL)

    ... number of scholars who studied the subject, Thucydides' description does not accurately fit any existing disease, but we suggest that analysis of the signs and symptoms, considered in conjunction with significant epidemiological evidence, narrows down the many possibilities to epidemic typhus, plague, arboviral disease ...

  8. Overcrowding and disease epidemics in colonial Lagos: rethinking ...

    African Journals Online (AJOL)

    Thus, it degenerated to overcrowding and disease epidemics as epitomised by the outbreak of tuberculosis and bubonic plague in 1919 and between 1924 and 1930 respectively. The paper, therefore, concludes that with the available evidence at our disposal, it is obvious that the road and railway were constructed to ...

  9. Virulence evolution at the front line of spreading epidemics.

    Science.gov (United States)

    Griette, Quentin; Raoul, Gaël; Gandon, Sylvain

    2015-11-01

    Understanding and predicting the spatial spread of emerging pathogens is a major challenge for the public health management of infectious diseases. Theoretical epidemiology shows that the speed of an epidemic is governed by the life-history characteristics of the pathogen and its ability to disperse. Rapid evolution of these traits during the invasion may thus affect the speed of epidemics. Here we study the influence of virulence evolution on the spatial spread of an epidemic. At the edge of the invasion front, we show that more virulent and transmissible genotypes are expected to win the competition with other pathogens. Behind the front line, however, more prudent exploitation strategies outcompete virulent pathogens. Crucially, even when the presence of the virulent mutant is limited to the edge of the front, the invasion speed can be dramatically altered by pathogen evolution. We support our analysis with individual-based simulations and we discuss the additional effects of demographic stochasticity taking place at the front line on virulence evolution. We confirm that an increase of virulence can occur at the front, but only if the carrying capacity of the invading pathogen is large enough. These results are discussed in the light of recent empirical studies examining virulence evolution at the edge of spreading epidemics. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  10. Topology dependent epidemic spreading velocity in weighted networks

    NARCIS (Netherlands)

    Duan, W.; Quax, R.; Lees, M.; Qiu, X.; Sloot, P.M.A.

    2014-01-01

    Many diffusive processes occur on structured networks with weighted links, such as disease spread by airplane transport or information diffusion in social networks or blogs. Understanding the impact of weight-connectivity correlations on epidemic spreading in weighted networks is crucial to support

  11. Addressing the "Epidemic" of Overweight Children by Using the Internet

    Science.gov (United States)

    Coleman, Mick; Wallinga, Charlotte; Bales, Diane

    2009-01-01

    The Internet can be of great assistance to early childhood teachers in planning educational activities for the classroom and with families. This article explores how early childhood teachers can use resources online to address what has been called an "epidemic" of overweight children. Guidelines for using online resources are presented. (Contains…

  12. Porcine Epidemic Diarrhea Virus among Farmed Pigs, Ukraine.

    Science.gov (United States)

    Dastjerdi, Akbar; Carr, John; Ellis, Richard J; Steinbach, Falko; Williamson, Susanna

    2015-12-01

    An outbreak of porcine epidemic diarrhea occurred in the summer of 2014 in Ukraine, severely affecting piglets <10 days of age; the mortality rate approached 100%. Full genome sequencing showed the virus to be closely related to strains reported from North America, showing a sequence identity of up to 99.8%.

  13. Resolving epidemic network failures through differentiated repair times

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Ruepp, Sarah Renée; Manzano, Marc

    2015-01-01

    In this study, the authors investigate epidemic failure spreading in large-scale transport networks under generalisedmulti-protocol label switching control plane. By evaluating the effect of the epidemic failure spreading on the network,they design several strategies for cost-effective network pe...... assigninglower repair times among the network nodes. They believe that the event-driven simulation model can be highly beneficialfor network providers, since it could be used during the network planning process for facilitating cost-effective networksurvivability design.......In this study, the authors investigate epidemic failure spreading in large-scale transport networks under generalisedmulti-protocol label switching control plane. By evaluating the effect of the epidemic failure spreading on the network,they design several strategies for cost-effective network...... performance improvement via differentiated repair times. First, theyidentify the most vulnerable and the most strategic nodes in the network. Then, via extensive event-driven simulations theyshow that strategic placement of resources for improved failure recovery has better performance than randomly...

  14. Effect of risk perception on epidemic spreading in temporal networks

    Science.gov (United States)

    Moinet, Antoine; Pastor-Satorras, Romualdo; Barrat, Alain

    2018-01-01

    Many progresses in the understanding of epidemic spreading models have been obtained thanks to numerous modeling efforts and analytical and numerical studies, considering host populations with very different structures and properties, including complex and temporal interaction networks. Moreover, a number of recent studies have started to go beyond the assumption of an absence of coupling between the spread of a disease and the structure of the contacts on which it unfolds. Models including awareness of the spread have been proposed, to mimic possible precautionary measures taken by individuals that decrease their risk of infection, but have mostly considered static networks. Here, we adapt such a framework to the more realistic case of temporal networks of interactions between individuals. We study the resulting model by analytical and numerical means on both simple models of temporal networks and empirical time-resolved contact data. Analytical results show that the epidemic threshold is not affected by the awareness but that the prevalence can be significantly decreased. Numerical studies on synthetic temporal networks highlight, however, the presence of very strong finite-size effects, resulting in a significant shift of the effective epidemic threshold in the presence of risk awareness. For empirical contact networks, the awareness mechanism leads as well to a shift in the effective threshold and to a strong reduction of the epidemic prevalence.

  15. The effect of awareness on networked SIS epidemics

    KAUST Repository

    Paarporn, Keith

    2017-01-05

    We study an SIS epidemic model over an arbitrary fixed network topology where the n agents, or nodes of the network, have partial information about the epidemic state. The agents react by distancing themselves from their neighbors when they believe the epidemic is currently prevalent. An agent\\'s awareness is weighted from three sources of information: the fraction of infected neighbors in their contact network, their social network, and a global broadcast of the fraction of infected nodes in the entire network. The dynamics of the benchmark (no awareness) and awareness models are described by discrete-time 2-state Markov chains. Through a coupling technique, we establish monotonicity properties between the benchmark and awareness models. Particularly, we show that the expectation of any increasing random variable on the space of sample paths, e.g. eradication time or total infections, is lower for the awareness model. In addition, we give a characterization for this difference of expectations in terms of the coupling distribution. In simulations, we evaluate how different sources of information affect the spread of an epidemic.

  16. [MPOWER--strategy for fighting the global tobacco epidemic].

    Science.gov (United States)

    Kaleta, Dorota; Kozieł, Anna; Miśkiewicz, Paulina

    2009-01-01

    It is estimated that tobacco use may cause death of 5 million people in 2008, which is higher than the number of deaths attributed to tuberculosis (TB), HIV/AIDS and malaria taken together. By 2030, the number of deaths related to the tobacco epidemic could exceed annually even 8 million. Despite many difficulties, a growing number of countries undertake intensive actions aimed at tobacco control. The objective of this paper was to discuss the major objectives of the MPOWER Report issued by the World Health Organization (WHO). The MPOWER package consists a set of six key and most effective strategies for fighting the global tobacco epidemic: 1) Monitoring tobacco consumption and the effectiveness of preventive measures; 2) Protect people from tobacco smoke; 3) Offer help to quit tobacco use; 4) Warn about the dangers of tobacco; 5) Enforce bans on tobacco advertising, promotion and sponsorship; and 6) Raise taxes on tobacco. It is proven that these strategies implemented in the compatible way, effectively decreases tobacco use. In addition, MPOWER comprises epidemiological data, information on implemented tobacco control measures and their efficiency. MPOWER is the only one document of a somewhat strategic nature that is a source of information on the spread of tobacco epidemic, as well as of suggestions concerning specific actions for supporting the fight against this epidemic.

  17. THE EPIDEMIC OF JUSTINIAN (AD 542): A PRELUDE TO THE ...

    African Journals Online (AJOL)

    ABSTRACT. The epidemic that struck Constantinople and the surrounding countries during the ... tical manpower shortage in the army were further effects which all contributed to bringing to a ... (Byzantium) from AD 527 to 565, a century after the fall of Rome and the Western ..... In Constantinople, economic decline and ...

  18. EDITORIAL Plagiarism - time to strike at the epidemic

    African Journals Online (AJOL)

    admin

    Plagiarism - time to strike at the epidemic. Lukman Yusuf1, Abraham Aseffa2. We live in a globalized world where information is instantly shared across continents. The number of biomedical journals available for reference is quite enormous and there is a sudden huge surge of free open access journals in the last few years ...

  19. Sudden transitions in coupled opinion and epidemic dynamics with vaccination

    Science.gov (United States)

    Pires, Marcelo A.; Oestereich, André L.; Crokidakis, Nuno

    2018-05-01

    This work consists of an epidemic model with vaccination coupled with an opinion dynamics. Our objective was to study how disease risk perception can influence opinions about vaccination and therefore the spreading of the disease. Differently from previous works we have considered continuous opinions. The epidemic spreading is governed by an SIS-like model with an extra vaccinated state. In our model individuals vaccinate with a probability proportional to their opinions. The opinions change due to peer influence in pairwise interactions. The epidemic feedback to the opinion dynamics acts as an external field increasing the vaccination probability. We performed Monte Carlo simulations in fully-connected populations. Interestingly we observed the emergence of a first-order phase transition, besides the usual active-absorbing phase transition presented in the SIS model. Our simulations also show that with a certain combination of parameters, an increment in the initial fraction of the population that is pro-vaccine has a twofold effect: it can lead to smaller epidemic outbreaks in the short term, but it also contributes to the survival of the chain of infections in the long term. Our results also suggest that it is possible that more effective vaccines can decrease the long-term vaccine coverage. This is a counterintuitive outcome, but it is in line with empirical observations that vaccines can become a victim of their own success.

  20. The global spread of HIV-1 subtype B epidemic.

    Science.gov (United States)

    Magiorkinis, Gkikas; Angelis, Konstantinos; Mamais, Ioannis; Katzourakis, Aris; Hatzakis, Angelos; Albert, Jan; Lawyer, Glenn; Hamouda, Osamah; Struck, Daniel; Vercauteren, Jurgen; Wensing, Annemarie; Alexiev, Ivailo; Åsjö, Birgitta; Balotta, Claudia; Gomes, Perpétua; Camacho, Ricardo J; Coughlan, Suzie; Griskevicius, Algirdas; Grossman, Zehava; Horban, Anders; Kostrikis, Leondios G; Lepej, Snjezana J; Liitsola, Kirsi; Linka, Marek; Nielsen, Claus; Otelea, Dan; Paredes, Roger; Poljak, Mario; Puchhammer-Stöckl, Elizabeth; Schmit, Jean Claude; Sönnerborg, Anders; Staneková, Danica; Stanojevic, Maja; Stylianou, Dora C; Boucher, Charles A B; Nikolopoulos, Georgios; Vasylyeva, Tetyana; Friedman, Samuel R; van de Vijver, David; Angarano, Gioacchino; Chaix, Marie-Laure; de Luca, Andrea; Korn, Klaus; Loveday, Clive; Soriano, Vincent; Yerly, Sabine; Zazzi, Mauricio; Vandamme, Anne-Mieke; Paraskevis, Dimitrios

    2016-12-01

    Human immunodeficiency virus type 1 (HIV-1) was discovered in the early 1980s when the virus had already established a pandemic. For at least three decades the epidemic in the Western World has been dominated by subtype B infections, as part of a sub-epidemic that traveled from Africa through Haiti to United States. However, the pattern of the subsequent spread still remains poorly understood. Here we analyze a large dataset of globally representative HIV-1 subtype B strains to map their spread around the world over the last 50years and describe significant spread patterns. We show that subtype B travelled from North America to Western Europe in different occasions, while Central/Eastern Europe remained isolated for the most part of the early epidemic. Looking with more detail in European countries we see that the United Kingdom, France and Switzerland exchanged viral isolates with non-European countries than with European ones. The observed pattern is likely to mirror geopolitical landmarks in the post-World War II era, namely the rise and the fall of the Iron Curtain and the European colonialism. In conclusion, HIV-1 spread through specific migration routes which are consistent with geopolitical factors that affected human activities during the last 50years, such as migration, tourism and trade. Our findings support the argument that epidemic control policies should be global and incorporate political and socioeconomic factors. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Towards flexible decision support in thecontrol of animal epidemics

    NARCIS (Netherlands)

    Ge, L.; Mourits, M.C.M.; Huirne, R.B.M.

    2007-01-01

    Decision-making in the control of animal epidemics is a dynamic and flexible process. Facing uncertainties about the consequences of control options, flexible decision-making can avoid unnecessary control costs through learning and adjusting. While recognising the importance and complexity of

  2. Etoposide for epidemic Kaposi's sarcoma: a phase II study

    NARCIS (Netherlands)

    Bakker, P. J.; Danner, S. A.; Lange, J. M.; Veenhof, K. H.

    1988-01-01

    Fourteen untreated patients with epidemic Kaposi's sarcoma stages III and IV were treated with etoposide 150 mg/m2 on 3 consecutive days every 4 weeks. No responses were observed. Myelosuppression was severe with white blood count WHO grade 3-4 in nine patients and with platelets WHO grade 3-4 in

  3. One Hundred Years in the Making: The Global Tobacco Epidemic.

    Science.gov (United States)

    Wipfli, Heather; Samet, Jonathan M

    2016-01-01

    Today's global tobacco epidemic may represent one of the first instances of the globalization of a noninfectious cause of disease. This article focuses on the first century of the global tobacco epidemic and its current status, reviewing the current and projected future of the global tobacco epidemic and the steps that are in progress to end it. In the United States and many countries of Western Europe, tobacco consumption peaked during the 1960s and 1970s and declined as tobacco control programs were initiated, motivated by the evidence indicting smoking as a leading cause of disease. Despite this policy advancement and the subsequent reductions in tobacco consumption, the global tobacco epidemic continued to grow exponentially in the later years of the twentieth century, as the multinational companies sought new markets to replace those shrinking in high-income countries. In response, between 2000 and 2004, the World Health Organization developed its first public health treaty, the Framework Convention on Tobacco Control, which entered into force in 2005. An accompanying package of interventions has been implemented. New approaches to tobacco control, including plain packaging and single representation of brands, have been implemented by Australia and Uruguay, respectively, but have been challenged by the tobacco industry.

  4. The 1992 measles epidemic in Cape Town - a changing ...

    African Journals Online (AJOL)

    Over the last 6 years there has been a decline in the incidence of measles in Cape Town. However, during August 1992 an outbreak occurred, with cases reported at many schools in children presumably immunised. The objectives of this study were to characterise the epidemic in Cape Town and to determine possible ...

  5. The influence of the school year on measles epidemics

    DEFF Research Database (Denmark)

    Andreasen, Viggo

    The measles incidence record for Copenhagen 1880-1966 shows that the date of admission of new pupils has major impact on the structure of the epidemics, suggesting that measles transmission should be modelled in a way that accounts for the pulsed influx of new pupils. Assuming that the school year...

  6. A stochastic modeling of recurrent measles epidemic | Kassem ...

    African Journals Online (AJOL)

    A simple stochastic mathematical model is developed and investigated for the dynamics of measles epidemic. The model, which is a multi-dimensional diffusion process, includes susceptible individuals, latent (exposed), infected and removed individuals. Stochastic effects are assumed to arise in the process of infection of ...

  7. The epidemic of childhood obesity | du Toit | South African Medical ...

    African Journals Online (AJOL)

    South African Medical Journal. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 93, No 1 (2003) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. The epidemic of childhood obesity. G du Toit, M-T van der Merwe. Abstract.

  8. Examination of the Obesity Epidemic from a Behavioral Perspective

    Science.gov (United States)

    Shields, A. Tamlyn

    2009-01-01

    Obesity prevalence has doubled among adults and overweight has tripled among children since 1980. This article discusses behavioral approaches to the obesity epidemic, focusing on recent environmental changes, the resulting behaviors, and possible solutions. Over the last 4 decades, time spent in sedentary activities, the consumption of fast food,…

  9. Neoliberal science, Chinese style: Making and managing the 'obesity epidemic'.

    Science.gov (United States)

    Greenhalgh, Susan

    2016-08-01

    Science and Technology Studies has seen a growing interest in the commercialization of science. In this article, I track the role of corporations in the construction of the obesity epidemic, deemed one of the major public health threats of the century. Focusing on China, a rising superpower in the midst of rampant, state-directed neoliberalization, I unravel the process, mechanisms, and broad effects of the corporate invention of an obesity epidemic. Largely hidden from view, Western firms were central actors at every stage in the creation, definition, and governmental management of obesity as a Chinese disease. Two industry-funded global health entities and the exploitation of personal ties enabled actors to nudge the development of obesity science and policy along lines beneficial to large firms, while obscuring the nudging. From Big Pharma to Big Food and Big Soda, transnational companies have been profiting from the 'epidemic of Chinese obesity', while doing little to effectively treat or prevent it. The China case suggests how obesity might have been constituted an 'epidemic threat' in other parts of the world and underscores the need for global frameworks to guide the study of neoliberal science and policymaking.

  10. The chemical bases of the various AIDS epidemics: recreational ...

    Indian Academy of Sciences (India)

    Why did AIDS not rise and then decline exponentially owing to antiviral immunity like all other viral epidemics? Why is AIDS not contagious? Why would only HIV carriers get AIDS who use either recreational or anti-HIV drugs or are subject to malnutrition? Why is the mortality of HIV-antibody-positives treated with anti-HIV ...

  11. Dynamics of cholera epidemics with impulsive vaccination and disinfection.

    Science.gov (United States)

    Sisodiya, Omprakash Singh; Misra, O P; Dhar, Joydip

    2018-04-01

    Waterborne diseases have a tremendous influence on human life. The contaminated drinking water causes water-borne disease like cholera. Pulse vaccination is an important and effective strategy for the elimination of infectious diseases. A waterborne disease like cholera can also be controlled by using impulse technique. In this paper, we have proposed a delayed SEIRB epidemic model with impulsive vaccination and disinfection. We have studied the pulse vaccination strategy and sanitation to control the cholera disease. The existence and stability of the disease-free and endemic periodic solution are investigated both analytically and numerically. It is shown that there exists an infection-free periodic solution, using the impulsive dynamical system defined by the stroboscopic map. It is observed that the infection-free periodic solution is globally attractive when the impulse period is less than some critical value. From the analysis of the model, we have obtained a sufficient condition for the permanence of the epidemic with pulse vaccination. The main highlight of this paper is to introduce impulse technique along with latent period into the SEIRB epidemic model to investigate the role of pulse vaccination and disinfection on the dynamics of the cholera epidemics. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Molecular evolution and the natural history of select virus epidemics

    DEFF Research Database (Denmark)

    Bruhn, Christian Anders Wathne

    Molecular evolution of pathogenic viruses with RNA based genomes is most often fast enough to leave an informative genomic sequence signal within a timeframe that is relevant for the study of both recent and on-­‐going epidemics (and epizootics). The true power of molecular evolutionary methodolo...

  13. Understanding the epidemic of HIV in South Africa

    African Journals Online (AJOL)

    the worst HIV epidemics in Africa. The lack of ... The data collected by the Department of Health through their annual ... Epidemiology Research Unit, PO Box 30606, Braamfontein, 2017. Brian Williams. ... socio-economic conditions. In the Western Cape, ... differs significantly from the mean value, which is 12.0 months (11.3 ...

  14. Information Spreading in Epidemics and in Communication Networks

    DEFF Research Database (Denmark)

    Uekermann, Florian Philipp

    The PhD thesis revolves mainly around models of disease spreading and human behavior. We present models for different epidemic patterns of infectious diseases. This includes investigations of the trajectory of the 2014 Ebola outbreak in West-Africa, influenza evolution and the seasonal dynamics...

  15. Slow Epidemic of Lymphogranuloma Venereum L2b Strain

    Science.gov (United States)

    Spaargaren, Joke; Schachter, Julius; Moncada, Jeanne; de Vries, Henry J.C.; Fennema, Han S.A.; Peña, A. Salvador; Coutinho, Roel A.

    2005-01-01

    We traced the Chlamydia trachomatis L2b variant in Amsterdam and San Francisco. All recent lymphogranuloma venereum cases in Amsterdam were caused by the L2b variant. This variant was also present in the 1980s in San Francisco. Thus, the current "outbreak" is most likely a slowly evolving epidemic. PMID:16318741

  16. The looming epidemic of diabetes-associated tuberculosis

    DEFF Research Database (Denmark)

    Harries, A D; Lin, Y; Satyanarayana, S

    2011-01-01

    The prevalence of diabetes mellitus is increasing at a dramatic rate, and countries in Asia, particularly India and China, will bear the brunt of this epidemic. Persons with diabetes have a significantly increased risk of active tuberculosis (TB), which is two to three times higher than in persons...

  17. A social contagious model of the obesity epidemic

    Science.gov (United States)

    Huang, He; Yan, Zhijun; Chen, Yahong; Liu, Fangyan

    2016-11-01

    Obesity has been recognized as a global epidemic by WHO, followed by many empirical evidences to prove its infectiousness. However, the inter-person spreading dynamics of obesity are seldom studied. A distinguishing feature of the obesity epidemic is that it is driven by a social contagion process which cannot be perfectly described by the infectious disease models. In this paper, we propose a novel belief decision model based on the famous Dempster-Shafer theory of evidence to model obesity epidemic as the competing spread of two obesity-related behaviors: physical inactivity and physical activity. The transition of health states is described by an SIS model. Results reveal the existence of obesity epidemic threshold, above which obesity is quickly eradicated. When increasing the fading level of information spread, enlarging the clustering of initial obese seeds, or introducing small-world characteristics into the network topology, the threshold is easily met. Social discrimination against the obese people plays completely different roles in two cases: on one hand, when obesity cannot be eradicated, social discrimination can reduce the number of obese people; on the other hand, when obesity is eradicable, social discrimination may instead cause it breaking out.

  18. Epidemics in Networks : Modeling, Optimization and Security Games

    NARCIS (Netherlands)

    Omic, J.

    2010-01-01

    Epidemic theory has wide range of applications in computer networks, from spreading of malware to the information dissemination algorithms. Our society depends more strongly than ever on such computer networks. Many of these networks rely to a large extent on decentralization and self-organization.

  19. Obesity and kidney disease: hidden consequences of the epidemic ...

    African Journals Online (AJOL)

    Obesity has become a worldwide epidemic, and its prevalence has been projected to grow by 40% in the next decade. This increasing prevalence has implications for the risk of diabetes, cardiovascular disease and also for Chronic Kidney Disease. A high body mass index is one of the strongest risk factors for new-onset ...

  20. Dewey: A Panacea for the 'Schoolification' Epidemic

    Science.gov (United States)

    Ring, Emer; O'Sullivan, Lisha

    2018-01-01

    High quality early years' education is associated with providing a child-centred curriculum based on a knowledge of how young children learn. The global 'schoolification epidemic' has led to an increasing focus on prescribed curricula and presents as a serious threat to the quality of children's early years' experiences. Findings from research in…