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Sample records for h1n1 virus infection

  1. 1918 pandemic H1N1 DNA vaccine protects ferrets against 2007 H1N1 virus infection

    DEFF Research Database (Denmark)

    Bragstad, Karoline; Martel, Cyril Jean-Marie; Aasted, Bent

    of the H1N1 pandemic virus from 1918 induce protection in ferrets against infection with a H1N1 (A/New Caledonia/20/99(H1N1)) virus which was included in the conventional vaccine for the 2006-2007 season. The viruses are separated by a time interval of 89 years and differ by 21.2% in the HA1 protein...

  2. Experimental infection with H1N1 European swine influenza virus protects pigs from an infection with the 2009 pandemic H1N1 human influenza virus.

    Science.gov (United States)

    Busquets, Núria; Segalés, Joaquim; Córdoba, Lorena; Mussá, Tufaria; Crisci, Elisa; Martín-Valls, Gerard E; Simon-Grifé, Meritxell; Pérez-Simó, Marta; Pérez-Maíllo, Monica; Núñez, Jose I; Abad, Francesc X; Fraile, Lorenzo; Pina, Sonia; Majó, Natalia; Bensaid, Albert; Domingo, Mariano; Montoya, María

    2010-01-01

    The recent pandemic caused by human influenza virus A(H1N1) 2009 contains ancestral gene segments from North American and Eurasian swine lineages as well as from avian and human influenza lineages. The emergence of this A(H1N1) 2009 poses a potential global threat for human health and the fact that it can infect other species, like pigs, favours a possible encounter with other influenza viruses circulating in swine herds. In Europe, H1N1, H1N2 and H3N2 subtypes of swine influenza virus currently have a high prevalence in commercial farms. To better assess the risk posed by the A(H1N1) 2009 in the actual situation of swine farms, we sought to analyze whether a previous infection with a circulating European avian-like swine A/Swine/Spain/53207/2004 (H1N1) influenza virus (hereafter referred to as SwH1N1) generated or not cross-protective immunity against a subsequent infection with the new human pandemic A/Catalonia/63/2009 (H1N1) influenza virus (hereafter referred to as pH1N1) 21 days apart. Pigs infected only with pH1N1 had mild to moderate pathological findings, consisting on broncho-interstitial pneumonia. However, pigs inoculated with SwH1N1 virus and subsequently infected with pH1N1 had very mild lung lesions, apparently attributed to the remaining lesions caused by SwH1N1 infection. These later pigs also exhibited boosted levels of specific antibodies. Finally, animals firstly infected with SwH1N1 virus and latter infected with pH1N1 exhibited undetectable viral RNA load in nasal swabs and lungs after challenge with pH1N1, indicating a cross-protective effect between both strains. © INRA, EDP Sciences, 2010.

  3. Humans and ferrets with prior H1N1 influenza virus infections do not exhibit evidence of original antigenic sin after infection or vaccination with the 2009 pandemic H1N1 influenza virus.

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    O'Donnell, Christopher D; Wright, Amber; Vogel, Leatrice; Boonnak, Kobporn; Treanor, John J; Subbarao, Kanta

    2014-05-01

    The hypothesis of original antigenic sin (OAS) states that the imprint established by an individual's first influenza virus infection governs the antibody response thereafter. Subsequent influenza virus infection results in an antibody response against the original infecting virus and an impaired immune response against the newer influenza virus. The purpose of our study was to seek evidence of OAS after infection or vaccination with the 2009 pandemic H1N1 (2009 pH1N1) virus in ferrets and humans previously infected with H1N1 viruses with various antigenic distances from the 2009 pH1N1 virus, including viruses from 1935 through 1999. In ferrets, seasonal H1N1 priming did not diminish the antibody response to infection or vaccination with the 2009 pH1N1 virus, nor did it diminish the T-cell response, indicating the absence of OAS in seasonal H1N1 virus-primed ferrets. Analysis of paired samples of human serum taken before and after vaccination with a monovalent inactivated 2009 pH1N1 vaccine showed a significantly greater-fold rise in the titer of antibody against the 2009 pH1N1 virus than against H1N1 viruses that circulated during the childhood of each subject. Thus, prior experience with H1N1 viruses did not result in an impairment of the antibody response against the 2009 pH1N1 vaccine. Our data from ferrets and humans suggest that prior exposure to H1N1 viruses did not impair the immune response against the 2009 pH1N1 virus.

  4. Pandemic (H1N1) 2009 virus infection during pregnancy in South India.

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    Pramanick, Angsumita; Rathore, Swati; Peter, John V; Moorthy, Mahesh; Lionel, Jessie

    2011-04-01

    To assess the clinical profile of pregnant/puerperal women from a semi-urban Indian population who were infected with pandemic (H1N1) 2009 virus (P[H1N1]2009v) and to evaluate their outcome. In a cross-sectional study, 566 women (79 pregnant/puerperal, 487 nonpregnant) who presented to a tertiary care hospital with influenza-like illness were tested for P(H1N1)2009v by real-time reverse transcriptase polymerase chain reaction. Outcomes measures were the maternal mortality and the perinatal mortality rate (PMR). Twenty (25%) pregnant/puerperal and 144 (30%) nonpregnant women tested positive for P(H1N1)2009v, with 5 pregnant and 3 postpartum women requiring admission to the intensive care unit (ICU). P(H1N1)2009v-related mortality was higher in pregnant than nonpregnant women (25% versus 8%; P=0.04). In the pregnant/puerperal cohort, factors associated with death included delayed presentation (median 6days versus 1.5days in survivors; P=0.007), need for ICU admission (P=0.004), need for ventilation (P=0.001), and renal failure (P=0.001). The PMR was 55.5/1000 births compared with 33.5/1000 births in the hospital overall during the study period. In a low-income country, P(H1N1)2009v infection in pregnancy is associated with considerable mortality. Delayed presentation to a tertiary care center, lack of awareness, and restricted access to treatment might have contributed to the high mortality. Copyright © 2011 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  5. Serosurveillance for pandemic influenza A (H1N1 2009 virus infection in domestic elephants, Thailand.

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    Weena Paungpin

    Full Text Available The present study conducted serosurveillance for the presence of antibody to pandemic influenza A (H1N1 2009 virus (H1N1pdm virus in archival serum samples collected between 2009 and 2013 from 317 domestic elephants living in 19 provinces situated in various parts of Thailand. To obtain the most accurate data, hemagglutination-inhibition (HI assay was employed as the screening test; and sera with HI antibody titers ≥20 were further confirmed by other methods, including cytopathic effect/hemagglutination based-microneutralization (microNT and Western blot (WB assays using H1N1pdm matrix 1 (M1 or hemagglutinin (HA recombinant protein as the test antigen. Conclusively, the appropriate assays using HI in conjunction with WB assays for HA antibody revealed an overall seropositive rate of 8.5% (27 of 317. The prevalence of antibody to H1N1pdm virus was 2% (4/172 in 2009, 32% (17/53 in 2010, 9% (2/22 in 2011, 12% (1/8 in 2012, and 5% (3/62 in 2013. Notably, these positive serum samples were collected from elephants living in 7 tourist provinces of Thailand. The highest seropositive rate was obtained from elephants in Phuket, a popular tourist beach city. Young elephants had higher seropositive rate than older elephants. The source of H1N1pdm viral infection in these elephants was not explored, but most likely came from close contact with the infected mahouts or from the infected tourists who engaged in activities such as elephant riding and feeding. Nevertheless, it could not be excluded that elephant-to-elephant transmission did occur.

  6. Chest X-ray findings in children with influenza A (H1N1) virus infection

    International Nuclear Information System (INIS)

    Zhou Min; Guo Wanliang; Wang Jian

    2011-01-01

    Objective: To assess the chest X-ray radiographic findings in children with influenza A (H1N1) virus infection. Methods: The chest X-ray radiographs in 67 children with influenza A (H1N1) virus infection were reviewed in this study. The chest radiographs were obtained 3-8 days after the onset of symptoms and for the follow-up. Results: The abnormalities were bilateral in 53 patients and unilateral in 7 patients. The predominant radiographic findings were bilateral patchy consolidation (n=42) with rapid confluence in 10 patients, lobular consolidation (n=7) with interstitial hyperplasia in 1 patient 3 month later, diffuse consolidation (n=11) with interstitial hyperplasia in all patients after 3 month. Conclusion: The predominant chest X-ray radiographic findings are bilateral patchy consolidation and diffuse consolidation with interstitial hyperplasia afterward. (authors)

  7. Novel Influenza A (H1N1) Virus Infection in Children: Chest Radiographic and CT Evaluation

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    Choi, Min Jeong; Lee, Young Seok; Lee, Jee Young; Lee, Kun Song [Dankook University College of Medicine, Dankook University Hospital, Cheonan (Korea, Republic of)

    2010-12-15

    The purpose of this study was to evaluate the chest radiographic and CT findings of novel influenza A (H1N1) virus infection in children, the population that is more vulnerable to respiratory infection than adults. The study population comprised 410 children who were diagnosed with an H1N1 infection from August 24, 2009 to November 11, 2009 and underwent chest radiography at Dankook University Hospital in Korea. Six of these patients also underwent chest CT. The initial chest radiographs were classified as normal or abnormal. The abnormal chest radiographs and high resolution CT scans were assessed for the pattern and distribution of parenchymal lesions, and the presence of complications such as atelectasis, pleural effusion, and pneumomediastinum. The initial chest radiograph was normal in 384 of 410 (94%) patients and abnormal in 26 of 410 (6%) patients. Parenchymal abnormalities seen on the initial chest radiographs included prominent peribronchial marking (25 of 26, 96%), consolidation (22 of 26, 85%), and ground-glass opacities without consolidation (2 of 26, 8%). The involvement was usually bilateral (19 of 26, 73%) with the lower lung zone predominance (22 of 26, 85%). Atelectasis was observed in 12 (46%) and pleural effusion in 11 (42%) patients. CT (n = 6) scans showed peribronchovascular interstitial thickening (n = 6), ground-glass opacities (n = 5), centrilobular nodules (n = 4), consolidation (n = 3), mediastinal lymph node enlargement (n = 5), pleural effusion (n = 3), and pneumomediastinum (n = 3). Abnormal chest radiographs were uncommon in children with a swine-origin influenza A (H1N1) virus (S-OIV) infection. In children, H1N1 virus infection can be included in the differential diagnosis, when chest radiographs and CT scans show prominent peribronchial markings and ill-defined patchy consolidation with mediastinal lymph node enlargement, pleural effusion and pneumomediastinum

  8. Novel Influenza A (H1N1) Virus Infection in Children: Chest Radiographic and CT Evaluation

    International Nuclear Information System (INIS)

    Choi, Min Jeong; Lee, Young Seok; Lee, Jee Young; Lee, Kun Song

    2010-01-01

    The purpose of this study was to evaluate the chest radiographic and CT findings of novel influenza A (H1N1) virus infection in children, the population that is more vulnerable to respiratory infection than adults. The study population comprised 410 children who were diagnosed with an H1N1 infection from August 24, 2009 to November 11, 2009 and underwent chest radiography at Dankook University Hospital in Korea. Six of these patients also underwent chest CT. The initial chest radiographs were classified as normal or abnormal. The abnormal chest radiographs and high resolution CT scans were assessed for the pattern and distribution of parenchymal lesions, and the presence of complications such as atelectasis, pleural effusion, and pneumomediastinum. The initial chest radiograph was normal in 384 of 410 (94%) patients and abnormal in 26 of 410 (6%) patients. Parenchymal abnormalities seen on the initial chest radiographs included prominent peribronchial marking (25 of 26, 96%), consolidation (22 of 26, 85%), and ground-glass opacities without consolidation (2 of 26, 8%). The involvement was usually bilateral (19 of 26, 73%) with the lower lung zone predominance (22 of 26, 85%). Atelectasis was observed in 12 (46%) and pleural effusion in 11 (42%) patients. CT (n = 6) scans showed peribronchovascular interstitial thickening (n = 6), ground-glass opacities (n = 5), centrilobular nodules (n = 4), consolidation (n = 3), mediastinal lymph node enlargement (n = 5), pleural effusion (n = 3), and pneumomediastinum (n = 3). Abnormal chest radiographs were uncommon in children with a swine-origin influenza A (H1N1) virus (S-OIV) infection. In children, H1N1 virus infection can be included in the differential diagnosis, when chest radiographs and CT scans show prominent peribronchial markings and ill-defined patchy consolidation with mediastinal lymph node enlargement, pleural effusion and pneumomediastinum

  9. Bilateral Pulmonary Thromboembolism: An Unusual Presentation of Infection with Influenza A (H1N1 Virus

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    Parviz Saleh

    2010-06-01

    Full Text Available AbstractSwine flue is a highly contagious acute respiratory diseasecaused by a subtype of influenza A virus. Herein we presentthree patients with H1N1 infection complicated with pulmonarythromboembolism. The patients had chest pain and unexplaineddyspnea. Imaging studies showed bilateral hilar predominance.Computed tomographic angiography confirmed bilateral thromboembolism(an unusual presentation of H1N1 infection. We didnot find any predisposing factor including endothelial damage,stasis, or hypercoagulable state in these patients. They did notreceive any medication. After anticoagulation and treatment withoseltamivir, all the patients were discharged in good condition.To the best of our knowledge bilateral pulmonary thromboembolismhas not been reported in English language literature inpatients with swine flu infection. Appropriate diagnosis andtreatment will be life saving in this condition.Iran J Med Sci 2010; 35(2: 149-153.

  10. Outcomes of influenza A(H1N1)pdm09 virus infection

    DEFF Research Database (Denmark)

    Lynfield, Ruth; Davey, Richard; Dwyer, Dominic E

    2014-01-01

    BACKGROUND: Data from prospectively planned cohort studies on risk of major clinical outcomes and prognostic factors for patients with influenza A(H1N1)pdm09 virus are limited. In 2009, in order to assess outcomes and evaluate risk factors for progression of illness, two cohort studies were...

  11. Thoracic computerized tomographic (CT findings in 2009 influenza A (H1N1 virus infection in Isfahan, Iran

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    Mojtaba Rostami

    2011-01-01

    Full Text Available Background: Pandemic 2009 H1N1 influenza A virus arrived at Isfahan in August 2009. The virus is still circulating in the world. The abnormal thoracic computerized tomographic (CT scan findings vary widely among the studies of 2009 H1N1 influenza. We evaluated the thoracic CT findings in patients with 2009 H1N1 virus infection to describe findings compared to previously reported findings, and to suggest patterns that may be suggestive for 2009 influenza A (H1N1 in an appropriate clinical setting. Methods: Retrospectively, the archive of all patients with a diagnosis of 2009 H1N1 influenza A were reviewed, in Al-Zahra Hospital in Isfahan, central Iran, between September 23 rd 2009 to February 20 th 2010. Out of 216 patients with confirmed 2009 influenza A (H1N1 virus, 26 cases with abnormal CT were enrolled in the study. Radiologic findings were characterized by the type and pattern of opacities and zonal distribution. Results: Patchy infiltration (34.6%, lobar consolidation (30.8%, and interstitial infiltration (26.9% with airbronchogram (38.5% were the predominant findings in our patients. Bilateral distribution was seen in 80.8% of the patients. Only one patient (3.8% showed ground-glass opacity, predominant radiographic finding in the previous reports and severe acute respiratory syndrome (SARS. Conclusions: The most common thoracic CT findings in pandemic H1N1 were patchy infiltration, lobar consolidation, and interstitial infiltration with airbronchogram and bilateral distribution. While these findings can be associated with other infections; they may be suggestive to 2009 influenza A (H1N1 in the appropriate clinical setting. Various radiographic patterns can be seen in thoracic CT scans of the influenza patients. Imaging findings are nonspecific.

  12. Clinical and radiological features of pandemic H1N1 2009 influenza virus infection manifesting as acute febrile respiratory illness at their initial presentations: comparison with contemporaneous non-H1N1 patients

    International Nuclear Information System (INIS)

    Yun, Tae Jin; Park, Chang Min; Choi, Seung Hong; Lee, Hyun Ju; Goo, Jin Mo; Kwon, Gu Jin; Woo, Sung Koo; Park, Seung Hoon

    2011-01-01

    Background Since the first outbreak caused by the pandemic H1N1 2009 influenza in Mexico, the virus has spread widely across the world with meaningful morbidity and mortality. However, there are few data on the comparative investigations to assess the clinical and radiological features between the H1N1 patient and non-H1N1 patients. Purpose To assess the clinical and radiological features of patients infected by the pandemic H1N1 2009 flu virus at their initial presentation and to compare them with contemporaneous non-H1N1 patients with acute febrile respiratory illness. Material and Methods This retrospective study was approved by the ethics committee of the Armed Forces Medical Command, South Korea. From August to September 2009, 337 consecutive patients presented with an acute febrile respiratory illness in a tertiary military hospital. Reverse-transcriptase polymerase-chain-reaction tests were performed in 62 of these patients under the impression of H1N1 infection. Clinical and radiological features at their initial presentation were described for the H1N1 group (n = 35) and non-H1N1 group (n = 27) and compared between the two groups. Results Increased C-reactive protein level (97%) without leukocytosis (9%) or increased erythrocyte sedimentation rate (0%) was common in the H1N1 group at their initial presentation. On chest radiographs, 12 of 35 (34%) H1N1 patients had abnormal findings; nodules in 10 patients (83%) and consolidations in two (17%). Of the 28 H1N1 patients who underwent thin-section CT 16 patients (57%) showed abnormal findings; ground-glass opacities (GGOs) in 15 (94%), and nodules in 13 (81%). However, there were no significant differences between the H1N1 group and non-H1N1 group in terms of symptoms, laboratory results, or radiological findings (P > 0.05). Conclusion Patients with H1N1 infection show consistent clinical and radiological features at their initial presentation, however, clinical and radiological features of the H1N1 group are

  13. Clinical and radiological features of pandemic H1N1 2009 influenza virus infection manifesting as acute febrile respiratory illness at their initial presentations: comparison with contemporaneous non-H1N1 patients

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    Yun, Tae Jin (Dept. of Radiology, Armed Force Byukjae Hospital, Gyeonggi-do (Korea, Republic of); Dept. of Radiology, Seoul National Univ. Hospital, Seoul (Korea, Republic of)); Park, Chang Min; Choi, Seung Hong; Lee, Hyun Ju; Goo, Jin Mo (Dept. of Radiology, Seoul National Univ. Hospital, Seoul (Korea, Republic of)), email: cmpark@radiol.snu.ac.kr; Kwon, Gu Jin (Dept. of Family Medicine, Armed Force Byukjae Hospital, Gyeonggi-do (Korea, Republic of); Dept. of Family Medicine, Gangneung Asan Hospital, Gangneung (Korea, Republic of)); Woo, Sung Koo (Dept. of Radiology, Armed Force Byukjae Hospital, Gyeonggi-do (Korea, Republic of)); Park, Seung Hoon (Dept. of Internal Medicine, Armed Force Byukjae Hospital, Gyeonggi-do (Korea, Republic of))

    2011-05-15

    Background Since the first outbreak caused by the pandemic H1N1 2009 influenza in Mexico, the virus has spread widely across the world with meaningful morbidity and mortality. However, there are few data on the comparative investigations to assess the clinical and radiological features between the H1N1 patient and non-H1N1 patients. Purpose To assess the clinical and radiological features of patients infected by the pandemic H1N1 2009 flu virus at their initial presentation and to compare them with contemporaneous non-H1N1 patients with acute febrile respiratory illness. Material and Methods This retrospective study was approved by the ethics committee of the Armed Forces Medical Command, South Korea. From August to September 2009, 337 consecutive patients presented with an acute febrile respiratory illness in a tertiary military hospital. Reverse-transcriptase polymerase-chain-reaction tests were performed in 62 of these patients under the impression of H1N1 infection. Clinical and radiological features at their initial presentation were described for the H1N1 group (n = 35) and non-H1N1 group (n = 27) and compared between the two groups. Results Increased C-reactive protein level (97%) without leukocytosis (9%) or increased erythrocyte sedimentation rate (0%) was common in the H1N1 group at their initial presentation. On chest radiographs, 12 of 35 (34%) H1N1 patients had abnormal findings; nodules in 10 patients (83%) and consolidations in two (17%). Of the 28 H1N1 patients who underwent thin-section CT 16 patients (57%) showed abnormal findings; ground-glass opacities (GGOs) in 15 (94%), and nodules in 13 (81%). However, there were no significant differences between the H1N1 group and non-H1N1 group in terms of symptoms, laboratory results, or radiological findings (P > 0.05). Conclusion Patients with H1N1 infection show consistent clinical and radiological features at their initial presentation, however, clinical and radiological features of the H1N1 group are

  14. Epidemiological survey on pandemic influenza A (H1N1) virus infection in Kurdistan province, Islamic Republic of Iran, 2009.

    Science.gov (United States)

    Afrasiabian, S; Mohsenpour, B; Bagheri, K H; Barari, M; Ghaderi, E; Hashemi, R; Garibi, F

    2014-04-03

    This study evaluated the epidemiology of suspected cases of pandemic influenza A (H1N1) virus infection in 2009-2010 in Kurdistan province, a frontier province of the Islamic Republic of Iran. A questionnaire covering demographic characteristics, clinical presentation and outcome, and history of exposure and travel was completed by patients attending health centres and hospitals in the province. Nasal and throat swabs were analysed by RT-PCR. A total of 1059 suspected cases were assessed; H1N1 influenza A was confirmed in 157 (14.8%). The highest proportion of confirmed cases was 30.0%, among children aged Kurdistan.

  15. The early days of pandemic (H1N1 2009 virus infection in the central region of Portugal

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    V. Duque

    2010-11-01

    Full Text Available Background: The first case of pandemic (H1N1 2009 virus infection was diagnosed in the central region of Portugal on June 16, 2009, in a woman infected in Canada. Methods: The aim of our study was, first to characterize the clinical and epidemiologic aspects of all the patients with clinical manifestations included in the definition of a case for investigation with samples submitted to diagnosis of the pandemic (H1N1 2009 virus infection, in the central region of Portugal; second, to assess the precision of the case definition of case for investigation considered in the study according to the presence or the absence of fever at the moment of clinical observation. We reviewed the medical records of all the patients presenting with Influenza like-illness classified as a case for investigation and the first cases of patients infected with the new pandemic (H1N1 2009 virus, diagnosed in the central region of Portugal during the pandemic period between June and August, 2009, were analyzed. Real-time reverse-transcriptase polymerase-chain-reaction (RT-PCR testing was used to confirm the pandemic (H1N1 2009 virus infection. Data collection was performed using a standardized paper format in agreement with the General Health Directorate. Results and discussion: Pandemic (H1N1 2009 virus infection was confirmed in 255 patients. Overall, median age was 23 years and 42.7% were included in the category of 20 to 29 years. Confirmed infection in patients with less than 2 years or greater than 50 years was a rare event. The first cases were imported from Europe, namely France, Spain and England. In a second phase, pandemic (H1N1 2009 virus infection was acquired in the south of Portugal (Algarve. The incidence rate for pandemic (H1N1 2009 virus infection was 10.7 per 100,000 persons and was different according to the district. It was higher in the district of Coimbra and Guarda where the main roads are connecting to Europe. The median calculated incubation

  16. Manifestations of infection by the novel influenza A (H1N1) virus at chest computed tomography

    International Nuclear Information System (INIS)

    Verrastro, Carlos Gustavo Yuji; D'Ippolito, Giuseppe

    2009-01-01

    Objective: the objective of this study was to describe chest computed tomography findings in confirmed cases of infection by the novel influenza A (H1N1) virus. Materials and methods: computed tomography studies of nine patients with laboratory-confirmed infection by the novel influenza A (H1N1) virus were consensually evaluated by three observers. The sample of the present study included five male and four female patients with ages ranging from 14 to 64 years (mean, 40 years). Four of the patients were previously healthy, four were kidney transplant recipients and one was pregnant at the time of diagnosis. Presence, extent and distribution of the following findings were evaluated: ground-glass opacities; centrilobular nodules; consolidation; interlobular septa thickening; pleural effusion; lymphadenopathy. Results: The most frequent findings were ground-glass opacities, centrilobular nodules and consolidations, present in nine (100%), five (55%) and four (44%) of cases, respectively. Pleural effusions and lymphadenopathy were less common findings, occurring in only two (22%) of the cases. Conclusion: ground-glass opacities, centrilobular nodules and consolidation were the most frequent findings in cases of infection by the novel influenza A (H1N1) virus. These changes are not typical or unique to this agent and may also occur in other viral or bacterial infections. (author)

  17. Acute immune thrombocytopenic purpura in an adolescent with 2009 novel H1N1 influenza A virus infection

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    Chun-Yi Lee

    2011-09-01

    Full Text Available Although both leukopenia and thrombocytopenia are not uncommon hematological findings among patients with novel 2009 H1N1 influenza virus infection, immune thrombocytopenic purpura has rarely been shown to be associated with this novel influenza A infection. Here, we describe a previously healthy adolescent who presented with fever, influenza-like symptoms and acute onset of generalized petechiae and active oral mucosa bleeding on the third day of his illness. Severe leukopenia and thrombocytopenia were found. There was neither malignancy nor blast cells found by bone marrow aspiration. Real-time reverse transcriptase polymerase chain reaction was positive for novel 2009 H1N1 influenza infection. Novel influenza-associated atypical immune thrombocytopenic purpura was diagnosed. The patient recovered uneventfully after oseltamivir and methylprednisolone therapy.

  18. Chest Radiographic Findings of Novel Swine-Origin Influenza A (H1N1) Virus Infection in Children

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    Bae, So Young; Hong, Eun Sook; Paik, Sang Hyun; Park, Seong Jin; Cha, Jang Gyu; Lee, Hae Kyung [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Jang, Yun Woo [Dept. of Radiology, Soonchunhyang University Hospital, Seoul (Korea, Republic of)

    2011-06-15

    To analyze chest radiographic findings in children infected with laboratory confirmed novel swine-origin influenza A (H1N1) virus. Three hundred seventy-two out of 2,014 children with laboratory confirmed H1N1 infection and who also underwent a chest radiograph from September to November 2009 were enrolled in this study. Patients were divided into in-patients, out-patients, and patients with co-infections and further subdivided into with underlying disease and without underlying disease as well as age (<2 years old, 2-5 years, 5-10 years, 10-18 years old). The initial radiographs were evaluated for radiographic findings and the anatomic distribution of abnormalities. The initial radiographs were abnormal in 154 (41.39%) patients. The predominant radiographic findings were peribronchial wall opacity found in 85 (22.84%) patients and hyperinflation observed in 69 (18.54%) patients. Further, 75 (71.42%) patients exhibited central predominance and the right lower lung zone was also commonly involved. There were statistically significant differences in the radiological findings between in-patient and out-patient groups. However, there were no significant differences in the radiographic findings between in-patients and the co-infection group with respect the presence of underlying disease and age. Initial radiographs of children with laboratory confirmed H1N1 virus were abnormal in 41.39% of cases. The common radiographic findings included peribronchial opacities, hyperinflation, lower lung zonal distribution, and central predominance

  19. Radiological and Clinical Characteristics of a Military Outbreak of Pandemic H1N1 2009 Influenza Virus Infection

    International Nuclear Information System (INIS)

    Yun, Tae Jin; Kwon, Gu Jin; Oh, Mi Kyeong; Woo, Sung Koo; Park, Seung Hoon; Choi, Seung Hong; Lee, Hyun Ju; Goo, Jin Mo; Yim, Jae Joon; Kim, Jong Sung; Park, Chang Min

    2010-01-01

    To describe detailed clinical and radiological features of the pandemic H1N1 2009 influenza viral infection among healthy young males in a semiclosed institutionalized setting. A total of 18 patients confirmed with the pandemic H1N1 2009 influenza virus infection from July 18 to July 30, 2009 were enrolled in this study. Each patient underwent an evaluation to determine detailed clinical and radiological features. All patients presented with high fever (> 38.0..C), with accompanying symptoms of cough, rhinorrhea, sore throat, myalgia and diarrhea, and increased C-reactive protein (CRP) values with no leukocytosis nor elevated erythrocyte sedimentation rate (ESR). All patients, including one patient who progressed into acute respiratory distress syndrome, were treated with oseltamivir phosphate and quickly recovered from their symptoms. Chest radiographs showed abnormalities of small nodules and lobar consolidation in only two out of 18 patients. However, six of 12 patients who underwent thin-section CT examinations showed abnormal findings for small ground-glass opacities (GGOs) in addition to poorly-defined nodules with upper lobe predominance. In a population of healthy young adults, elevated CRP with normal ESR and white blood cell levels combined with GGOs and nodules on thin section CT scans may indicate early signs of infection by the pandemic H1N1 2009 influenza virus

  20. Productive infection of human skeletal muscle cells by pandemic and seasonal influenza A(H1N1 viruses.

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    Marion Desdouits

    Full Text Available Besides the classical respiratory and systemic symptoms, unusual complications of influenza A infection in humans involve the skeletal muscles. Numerous cases of acute myopathy and/or rhabdomyolysis have been reported, particularly following the outbreak of pandemic influenza A(H1N1 in 2009. The pathogenesis of these influenza-associated myopathies (IAM remains unkown, although the direct infection of muscle cells is suspected. Here, we studied the susceptibility of cultured human primary muscle cells to a 2009 pandemic and a 2008 seasonal influenza A(H1N1 isolate. Using cells from different donors, we found that differentiated muscle cells (i. e. myotubes were highly susceptible to infection by both influenza A(H1N1 isolates, whereas undifferentiated cells (i. e. myoblasts were partially resistant. The receptors for influenza viruses, α2-6 and α2-3 linked sialic acids, were detected on the surface of myotubes and myoblasts. Time line of viral nucleoprotein (NP expression and nuclear export showed that the first steps of the viral replication cycle could take place in muscle cells. Infected myotubes and myoblasts exhibited budding virions and nuclear inclusions as observed by transmission electron microscopy and correlative light and electron microscopy. Myotubes, but not myoblasts, yielded infectious virus progeny that could further infect naive muscle cells after proteolytic treatment. Infection led to a cytopathic effect with the lysis of muscle cells, as characterized by the release of lactate dehydrogenase. The secretion of proinflammatory cytokines by muscle cells was not affected following infection. Our results are compatible with the hypothesis of a direct muscle infection causing rhabdomyolysis in IAM patients.

  1. An Outbreak of 2009 Pandemic Influenza A (H1N1) Virus Infection in an Elementary School in Pennsylvania

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    Bhattarai, Achuyt; Fagan, Ryan P.; Ostroff, Stephen; Sodha, Samir V.; Moll, Mària E.; Lee, Bruce Y.; Chang, Chung-Chou H.; Ennis, Brent; Britz, Phyllis; Fiore, Anthony; Nguyen, Michael; Palekar, Rakhee; Archer, W. Roodly; Gift, Thomas L.; Leap, Rebecca; Nygren, Benjamin L.; Cauchemez, Simon; Angulo, Frederick J.; Swerdlow, David

    2011-01-01

    In May 2009, one of the earliest outbreaks of 2009 pandemic influenza A virus (pH1N1) infection resulted in the closure of a semi-rural Pennsylvania elementary school. Two sequential telephone surveys were administered to 1345 students (85% of the students enrolled in the school) and household members in 313 households to collect data on influenza-like illness (ILI). A total of 167 persons (12.4%) among those in the surveyed households, including 93 (24.0%) of the School A students, reported ILI. Students were 3.1 times more likely than were other household members to develop ILI (95% confidence interval [CI], 2.3–4.1). Fourth-grade students were more likely to be affected than were students in other grades (relative risk, 2.2; 95% CI, 1.2–3.9). pH1N1 was confirmed in 26 (72.2%) of the individuals tested by real-time reverse-transcriptase polymerase chain reaction. The outbreak did not resume upon the reopening of the school after the 7-day closure. This investigation found that pH1N1 outbreaks at schools can have substantial attack rates; however, grades and classrooms are affected variably. Additioanl study is warranted to determine the effectiveness of school closure during outbreaks. PMID:21342888

  2. Carbohydrate determinants in ferret conjunctiva are affected by infection with influenza H1N1 virus

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Martel, Cyril; Aasted, Bent

    2013-01-01

    Carbohydrates often accomplish as cell-surface receptors for microorganisms and influenza virus preferentially binds to sialic acid through the viral haemagglutinin. The virus may attach not only to the epithelium in the airways, but also to the surface ocular epithelium.......Carbohydrates often accomplish as cell-surface receptors for microorganisms and influenza virus preferentially binds to sialic acid through the viral haemagglutinin. The virus may attach not only to the epithelium in the airways, but also to the surface ocular epithelium....

  3. Pneumonia in novel swine-origin influenza A (H1N1) virus infection: High-resolution CT findings

    International Nuclear Information System (INIS)

    Li Ping; Su Dongju; Zhang Jifeng; Xia Xudong; Sui Hong; Zhao Donghui

    2011-01-01

    Objective: The purpose of our study was to review the initial high-resolution CT (HRCT) findings in pneumonia patients with presumed/laboratory-confirmed novel swine-origin influenza A (H1N1) virus (S-OIV) infection and detect pneumonia earlier. Materials and methods: High-resolution CT (HRCT) findings of 106 patients with presumed/laboratory-confirmed novel S-OIV (H1N1) infection were reviewed. The 106 patients were divided into two groups according to the serious condition of the diseases. The pattern (consolidation, ground-glass, nodules, and reticulation), distribution, and extent of abnormality on the HRCT were evaluated in both groups. The dates of the onset of symptoms of the patients were recorded. Results: The predominant CT findings in the patients at presentation were unilateral or bilateral multifocal asymmetric ground-glass opacities alone (n = 29, 27.4%), with unilateral or bilateral consolidation (n = 50, 47.2%). The consolidation had peribronchovascular and subpleural predominance. The areas of consolidation were found mainly in the posterior, middle and lower regions of the lungs. Reticular opacities were found in 6 cases of the initial MDCT scan. The extent of disease was greater in group 1 patients requiring advanced mechanical ventilation, with diffuse involvement in 19 patients (63.3%) of group 1 patients, and only 15/76 (19.7%) of group 2 patients (p 2 test). 20 cases (19%) of the 106 patients had small bilateral or unilateral pleural effusions. None had evidence of hilar or mediastinal lymph node enlargement on CT performed at admission or later. Conclusions: The most common radiographic and CT findings in patients with S-OIV infection are unilateral or bilateral ground-glass opacities with or without associated focal or multifocal areas of consolidation. On HRCT, the ground-glass opacities had a predominant peribronchovascular and subpleural distribution. CT plays an important role in the early recognition of severe S-OIV (H1N1).

  4. Fitness of Pandemic H1N1 and Seasonal influenza A viruses during Co-infection: Evidence of competitive advantage of pandemic H1N1 influenza versus seasonal influenza.

    Science.gov (United States)

    Perez, Daniel Roberto; Sorrell, Erin; Angel, Matthew; Ye, Jianqiang; Hickman, Danielle; Pena, Lindomar; Ramirez-Nieto, Gloria; Kimble, Brian; Araya, Yonas

    2009-08-24

    On June 11, 2009 the World Health Organization (WHO) declared a new H1N1 influenza pandemic. This pandemic strain is as transmissible as seasonal H1N1 and H3N2 influenza A viruses. Major concerns facing this pandemic are whether the new virus will replace, co-circulate and/or reassort with seasonal H1N1 and/or H3N2 human strains. Using the ferret model, we investigated which of these three possibilities were most likely favored. Our studies showed that the current pandemic virus is more transmissible than, and has a biological advantage over, prototypical seasonal H1 or H3 strains.

  5. Pneumonia in novel swine-origin influenza A (H1N1) virus infection: High-resolution CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Li Ping, E-mail: pinglee_2000@yahoo.com [Department of Radiology, The Second Affiliated Hospital of Harbin Medical University, 246 Xue Fu Road, Harbin 150086 (China); Su Dongju, E-mail: hyd_sdj@yahoo.com.cn [Department of Respiratory, The Second Affiliated Hospital of Harbin Medical University, 246 Xue Fu Road, Harbin 150086 (China); Zhang Jifeng, E-mail: zjf2005520@163.com [Department of Radiology, The Second Affiliated Hospital of Harbin Medical University, 246 Xue Fu Road, Harbin 150086 (China); Xia Xudong, E-mail: xiaxd888@163.com [Department of Radiology, The Second Affiliated Hospital of Harbin Medical University, 246 Xue Fu Road, Harbin 150086 (China); Sui Hong, E-mail: suisuihong@126.com [Department of Statistics, Harbin Medical University, 240 Xue Fu Road, Harbin 150086 (China); Zhao Donghui, E-mail: yhwoooooo@yahoo.com.cn [Centers for Disease Control and Prevention of Heilongjiang, 187 Xiang An Street, Harbin 150036 (China)

    2011-11-15

    Objective: The purpose of our study was to review the initial high-resolution CT (HRCT) findings in pneumonia patients with presumed/laboratory-confirmed novel swine-origin influenza A (H1N1) virus (S-OIV) infection and detect pneumonia earlier. Materials and methods: High-resolution CT (HRCT) findings of 106 patients with presumed/laboratory-confirmed novel S-OIV (H1N1) infection were reviewed. The 106 patients were divided into two groups according to the serious condition of the diseases. The pattern (consolidation, ground-glass, nodules, and reticulation), distribution, and extent of abnormality on the HRCT were evaluated in both groups. The dates of the onset of symptoms of the patients were recorded. Results: The predominant CT findings in the patients at presentation were unilateral or bilateral multifocal asymmetric ground-glass opacities alone (n = 29, 27.4%), with unilateral or bilateral consolidation (n = 50, 47.2%). The consolidation had peribronchovascular and subpleural predominance. The areas of consolidation were found mainly in the posterior, middle and lower regions of the lungs. Reticular opacities were found in 6 cases of the initial MDCT scan. The extent of disease was greater in group 1 patients requiring advanced mechanical ventilation, with diffuse involvement in 19 patients (63.3%) of group 1 patients, and only 15/76 (19.7%) of group 2 patients (p < 0.01, {chi}{sup 2} test). 20 cases (19%) of the 106 patients had small bilateral or unilateral pleural effusions. None had evidence of hilar or mediastinal lymph node enlargement on CT performed at admission or later. Conclusions: The most common radiographic and CT findings in patients with S-OIV infection are unilateral or bilateral ground-glass opacities with or without associated focal or multifocal areas of consolidation. On HRCT, the ground-glass opacities had a predominant peribronchovascular and subpleural distribution. CT plays an important role in the early recognition of severe S

  6. Oseltamivir for treatment and prevention of pandemic influenza A/H1N1 virus infection in households, Milwaukee, 2009

    Directory of Open Access Journals (Sweden)

    Miller Joel C

    2010-07-01

    Full Text Available Abstract Background During an influenza pandemic, a substantial proportion of transmission is thought to occur in households. We used data on influenza progression in individuals and their contacts collected by the City of Milwaukee Health Department (MHD to study the transmission of pandemic influenza A/H1N1 virus in 362 households in Milwaukee, WI, and the effects of oseltamivir treatment and chemoprophylaxis. Methods 135 households had chronological information on symptoms and oseltamivir usage for all household members. The effect of oseltamivir treatment and other factors on the household secondary attack rate was estimated using univariate and multivariate logistic regression with households as the unit of analysis. The effect of oseltamivir treatment and other factors on the individual secondary attack rate was estimated using univariate and multivariate logistic regression with individual household contacts as the unit of analysis, and a generalized estimating equations approach was used to fit the model to allow for clustering within households. Results Oseltamivir index treatment on onset day or the following day (early treatment was associated with a 42% reduction (OR: 0.58, 95% CI: 0.19, 1.73 in the odds of one or more secondary infections in a household and a 50% reduction (OR: 0.5, 95% CI: 0.17, 1.46 in the odds of a secondary infection in individual contacts. The confidence bounds are wide due to a small sample of households with early oseltamivir index usage - in 29 such households, 5 had a secondary attack. Younger household contacts were at higher risk of infection (OR: 2.79, 95% CI: 1.50-5.20. Conclusions Early oseltamivir treatment may be beneficial in preventing H1N1pdm influenza transmission; this may have relevance to future control measures for influenza pandemics. Larger randomized trials are needed to confirm this finding statistically.

  7. Comparative pathology of pigs infected with Korean H1N1, H1N2, or H3N2 swine influenza A viruses

    OpenAIRE

    Lyoo, Kwang-Soo; Kim, Jeong-Ki; Jung, Kwonil; Kang, Bo-Kyu; Song, Daesub

    2014-01-01

    Background The predominant subtypes of swine influenza A virus (SIV) in Korea swine population are H1N1, H1N2, and H3N2. The viruses are genetically close to the classical U.S. H1N1 and triple-reassortant H1N2 and H3N2 viruses, respectively. Comparative pathogenesis caused by Korean H1N1, H1N2, and H3N2 SIV was evaluated in this study. Findings The H3N2 infected pigs had severe scores of gross and histopathological lesions at post-inoculation days (PID) 2, and this then progressively decrease...

  8. Pandemic (H1N1 2009 Influenza Virus Infection in A Survivor who has recovered from severe H7N9 Virus Infection, China

    Directory of Open Access Journals (Sweden)

    Shan-Hui Chen

    2016-10-01

    Full Text Available We firstly report a patient who presented with severe complications after infection with influenza A(H1N1 pdm2009, more than one year after recovery from severe H7N9 virus infections. The population of patients who recovered from severe H7N9 infections might be at a higher risk to suffer severe complications after seasonal influenza infections, and they should be included in the high-risk populations recommended to receive seasonal influenza vaccination.

  9. Intensive cytokine induction in pandemic H1N1 influenza virus infection accompanied by robust production of IL-10 and IL-6.

    Science.gov (United States)

    Yu, Xuelian; Zhang, Xi; Zhao, Baihui; Wang, Jiayu; Zhu, Zhaokui; Teng, Zheng; Shao, Junjie; Shen, Jiaren; Gao, Ye; Yuan, Zhengan; Wu, Fan

    2011-01-01

    The innate immune system is the first line of defense against viruses by inducing expression of cytokines and chemokines. Many pandemic influenza H1N1 virus [P(H1N1)] infected severe cases occur in young adults under 18 years old who were rarely seriously affected by seasonal influenza. Results regarding host cytokine profiles of P(H1N1) are ambivalent. In the present study we investigated host cytokine profiles in P(H1N1) patients and identified cytokines related to disease severity. We retrieved 77, 59, 26 and 26 sera samples from P(H1N1) and non-flu influenza like illness (non-ILIs) cases with mild symptoms (mild patients), P(H1N1) vaccinees and healthy individuals, respectively. Nine and 16 sera were from hospitalized P(H1N1) and non-ILIs patients with severe symptoms (severe patients). Cytokines of IL-1, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IFN-γ and TNF-α were assayed by cytokine bead array, IL-17 and IL-23 measured with ELISA. Mild P(H1N1) patients produced significantly elevated IL-2, IL-12, IFN-γ, IL-6, TNF-α, IL-5, IL-10, IL-17 and IL-23 versus to healthy controls. While an overwhelming IL-6 and IL-10 production were observed in severe P(H1N1) patients. Higher IL-10 secretion in P(H1N1) vaccinees confirmed our observation that highly increased level of sera IL-6 and IL-10 in P(H1N1) patients may lead to disease progression. A comprehensive innate immune response was activated at the early stage of P(H1N1) infection with a combine Th1/Th2/Th3 cytokines production. As disease progression, a systemic production of IL-6 and IL-10 were observed in severe P(H1N1) patients. Further analysis found a strong correlation between IL-6 and IL-10 production in the severe P(H1N1) patients. IL-6 may be served as a mediator to induce IL-10 production. Highly elevated level of sera IL-6 and IL-10 in P(H1N1) patients may lead to disease progression, but the underlying mechanism awaits further detailed investigations.

  10. Intensive cytokine induction in pandemic H1N1 influenza virus infection accompanied by robust production of IL-10 and IL-6.

    Directory of Open Access Journals (Sweden)

    Xuelian Yu

    Full Text Available BACKGROUND: The innate immune system is the first line of defense against viruses by inducing expression of cytokines and chemokines. Many pandemic influenza H1N1 virus [P(H1N1] infected severe cases occur in young adults under 18 years old who were rarely seriously affected by seasonal influenza. Results regarding host cytokine profiles of P(H1N1 are ambivalent. In the present study we investigated host cytokine profiles in P(H1N1 patients and identified cytokines related to disease severity. METHODS AND PRINCIPAL FINDINGS: We retrieved 77, 59, 26 and 26 sera samples from P(H1N1 and non-flu influenza like illness (non-ILIs cases with mild symptoms (mild patients, P(H1N1 vaccinees and healthy individuals, respectively. Nine and 16 sera were from hospitalized P(H1N1 and non-ILIs patients with severe symptoms (severe patients. Cytokines of IL-1, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IFN-γ and TNF-α were assayed by cytokine bead array, IL-17 and IL-23 measured with ELISA. Mild P(H1N1 patients produced significantly elevated IL-2, IL-12, IFN-γ, IL-6, TNF-α, IL-5, IL-10, IL-17 and IL-23 versus to healthy controls. While an overwhelming IL-6 and IL-10 production were observed in severe P(H1N1 patients. Higher IL-10 secretion in P(H1N1 vaccinees confirmed our observation that highly increased level of sera IL-6 and IL-10 in P(H1N1 patients may lead to disease progression. CONCLUSION AND SIGNIFICANCE: A comprehensive innate immune response was activated at the early stage of P(H1N1 infection with a combine Th1/Th2/Th3 cytokines production. As disease progression, a systemic production of IL-6 and IL-10 were observed in severe P(H1N1 patients. Further analysis found a strong correlation between IL-6 and IL-10 production in the severe P(H1N1 patients. IL-6 may be served as a mediator to induce IL-10 production. Highly elevated level of sera IL-6 and IL-10 in P(H1N1 patients may lead to disease progression, but the underlying mechanism awaits

  11. The association between serum biomarkers and disease outcome in influenza A(H1N1)pdm09 virus infection

    DEFF Research Database (Denmark)

    Davey, Richard T; Lynfield, Ruth; Dwyer, Dominic E

    2013-01-01

    Prospective studies establishing the temporal relationship between the degree of inflammation and human influenza disease progression are scarce. To assess predictors of disease progression among patients with influenza A(H1N1)pdm09 infection, 25 inflammatory biomarkers measured at enrollment wer...

  12. Avian influenza viruses that cause highly virulent infections in humans exhibit distinct replicative properties in contrast to human H1N1 viruses

    Science.gov (United States)

    Simon, Philippe F.; de La Vega, Marc-Antoine; Paradis, Éric; Mendoza, Emelissa; Coombs, Kevin M.; Kobasa, Darwyn; Beauchemin, Catherine A. A.

    2016-04-01

    Avian influenza viruses present an emerging epidemiological concern as some strains of H5N1 avian influenza can cause severe infections in humans with lethality rates of up to 60%. These have been in circulation since 1997 and recently a novel H7N9-subtyped virus has been causing epizootics in China with lethality rates around 20%. To better understand the replication kinetics of these viruses, we combined several extensive viral kinetics experiments with mathematical modelling of in vitro infections in human A549 cells. We extracted fundamental replication parameters revealing that, while both the H5N1 and H7N9 viruses replicate faster and to higher titers than two low-pathogenicity H1N1 strains, they accomplish this via different mechanisms. While the H7N9 virions exhibit a faster rate of infection, the H5N1 virions are produced at a higher rate. Of the two H1N1 strains studied, the 2009 pandemic H1N1 strain exhibits the longest eclipse phase, possibly indicative of a less effective neuraminidase activity, but causes infection more rapidly than the seasonal strain. This explains, in part, the pandemic strain’s generally slower growth kinetics and permissiveness to accept mutations causing neuraminidase inhibitor resistance without significant loss in fitness. Our results highlight differential growth properties of H1N1, H5N1 and H7N9 influenza viruses.

  13. Comparative pathology of pigs infected with Korean H1N1, H1N2, or H3N2 swine influenza A viruses.

    Science.gov (United States)

    Lyoo, Kwang-Soo; Kim, Jeong-Ki; Jung, Kwonil; Kang, Bo-Kyu; Song, Daesub

    2014-09-24

    The predominant subtypes of swine influenza A virus (SIV) in Korea swine population are H1N1, H1N2, and H3N2. The viruses are genetically close to the classical U.S. H1N1 and triple-reassortant H1N2 and H3N2 viruses, respectively. Comparative pathogenesis caused by Korean H1N1, H1N2, and H3N2 SIV was evaluated in this study. The H3N2 infected pigs had severe scores of gross and histopathological lesions at post-inoculation days (PID) 2, and this then progressively decreased. Both the H1N1 and H1N2 infected pigs lacked gross lesions at PID 2, but they showed moderate to severe pneumonia on PID 4, 7 and 14. The pigs infected with H1N1 had significant scores of gross and histopathological lesions when compared with the other pigs infected with H1N2, H3N2, and mock at PID 14. Mean SIV antigen-positive scores were rarely detected for pigs infected with H1N2 and H3N2 from PID 7, whereas a significantly increased amount of viral antigens were found in the bronchioles and alveolar epithelium of the H1N1infected pigs at PID 14. We demonstrated that Korean SIV subtypes had different pulmonary pathologic patterns. The Korean H3N2 rapidly induced acute lung lesions such as broncho-interstitial pneumonia, while the Korean H1N1 showed longer course of infection as compared to other strains.

  14. TNF, IL6, and IL1B Polymorphisms Are Associated with Severe Influenza A (H1N1) Virus Infection in the Mexican Population

    Science.gov (United States)

    García-Ramírez, Román Alejandro; Ramírez-Venegas, Alejandra; Quintana-Carrillo, Roger; Camarena, Ángel Eduardo; Falfán-Valencia, Ramcés; Mejía-Aranguré, Juan Manuel

    2015-01-01

    Background Hypercytokinemia is the main immunopathological mechanism contributing to a more severe clinical course in influenza A (H1N1) virus infections. Most patients infected with the influenza A (H1N1) pdm09 virus had increased systemic levels of pro-inflammatory cytokines; including interleukin IL-6, IL-8, and tumor necrosis factor-alpha (TNF-α). We propose that single-nucleotide polymorphisms (SNPs) in the promoter regions of pro-inflammatory genes are associated with the severity of influenza A (H1N1) pdm09 virus infection. Methods 145 patients with influenza A (H1N1) (pA/H1N1), 133 patients with influenza-like illness (ILI), and 360 asymptomatic healthy contacts (AHCs) were included. Eleven SNPs were genotyped in six genes (TNF, LT, IL1B, IL6, CCL1, and IL8) using real-time PCR; the ancestral genotype was used for comparison. Genotypes were correlated with 27 clinical severity variables. Ten cytokines (GM-CSF, TNF-α, IL-2, IL-1β, IL-6, IL-8, IFN-γ, IL-10, IL-5, and IL-4) were measured on a Luminex 100. Results The IL6 rs1818879 (GA) heterozygous genotype was associated with severe influenza A (H1N1) virus infection (odds ratio [OR] = 5.94, 95% confidence interval [CI] 3.05–11.56), and two IL1B SNPs, rs16944 AG and rs3136558 TC, were associated with a decreased risk of infection (OR = 0.52 and OR = 0.51, respectively). Genetic susceptibility was determined (pA/H1N1 vs. AHC): the LTA rs909253 TC heterozygous genotype conferred greater risk (OR = 1.9), and a similar association was observed with the IL1B rs3136558 CC genotype (OR = 1.89). Additionally, severely ill patients were compared with moderately ill patients. The TNF-238 GA genotype was associated with an increased risk of disease severity (OR = 16.06, p = 0.007). Compared with ILIs, patients with severe pA/H1N1 infections exhibited increased serum IL-5 (p <0.001) and IL-6 (p  =  0.007) levels. Conclusions The TNF gene was associated with disease severity, whereas IL1B and IL6 SNPs were

  15. TNF, IL6, and IL1B Polymorphisms Are Associated with Severe Influenza A (H1N1 Virus Infection in the Mexican Population.

    Directory of Open Access Journals (Sweden)

    Román Alejandro García-Ramírez

    Full Text Available Hypercytokinemia is the main immunopathological mechanism contributing to a more severe clinical course in influenza A (H1N1 virus infections. Most patients infected with the influenza A (H1N1 pdm09 virus had increased systemic levels of pro-inflammatory cytokines; including interleukin IL-6, IL-8, and tumor necrosis factor-alpha (TNF-α. We propose that single-nucleotide polymorphisms (SNPs in the promoter regions of pro-inflammatory genes are associated with the severity of influenza A (H1N1 pdm09 virus infection.145 patients with influenza A (H1N1 (pA/H1N1, 133 patients with influenza-like illness (ILI, and 360 asymptomatic healthy contacts (AHCs were included. Eleven SNPs were genotyped in six genes (TNF, LT, IL1B, IL6, CCL1, and IL8 using real-time PCR; the ancestral genotype was used for comparison. Genotypes were correlated with 27 clinical severity variables. Ten cytokines (GM-CSF, TNF-α, IL-2, IL-1β, IL-6, IL-8, IFN-γ, IL-10, IL-5, and IL-4 were measured on a Luminex 100.The IL6 rs1818879 (GA heterozygous genotype was associated with severe influenza A (H1N1 virus infection (odds ratio [OR] = 5.94, 95% confidence interval [CI] 3.05-11.56, and two IL1B SNPs, rs16944 AG and rs3136558 TC, were associated with a decreased risk of infection (OR = 0.52 and OR = 0.51, respectively. Genetic susceptibility was determined (pA/H1N1 vs. AHC: the LTA rs909253 TC heterozygous genotype conferred greater risk (OR = 1.9, and a similar association was observed with the IL1B rs3136558 CC genotype (OR = 1.89. Additionally, severely ill patients were compared with moderately ill patients. The TNF-238 GA genotype was associated with an increased risk of disease severity (OR = 16.06, p = 0.007. Compared with ILIs, patients with severe pA/H1N1 infections exhibited increased serum IL-5 (p <0.001 and IL-6 (p  =  0.007 levels.The TNF gene was associated with disease severity, whereas IL1B and IL6 SNPs were associated with influenza A (H1N1 virus

  16. Radiologic Review of an Outbreak of the Pandemic (H1N1) 2009 Virus Infection at a University Hospital in Seoul, Korea

    International Nuclear Information System (INIS)

    Choi, Seung Hee; Kang, Eun Young; Kim, Yoon Kyung; Woo, Ok Hee; Yong, Hwan Seok; Oh, Yu Whan; Kim, Jang Su

    2011-01-01

    To assess the frequency of radiologic abnormalities and investigate the radiologic findings of patients with a pandemic (H1N1) 2009 virus infection at a University hospital in Seoul, Korea. In November 2009, 9,427 patients were tested for pandemic (H1N1) 2009 virus and 3,849 (41%) were positive. Among them, only 338 (9%) underwent chest radiographs and 13 (0.3%) received chest CT. Two radiologists retrospectively reviewed all the radiologic images. Among the 338 patients, 287 (85%) were normal and 51 (15%) showed abnormalities. The frequency of abnormalities was significantly higher in children (41/212=19%) than in adults (10/126=8%) (p = 0.005). Of them, 42 (82%) patients had airspace pneumonia, whereas the remaining patients showed a bronchopneumonia pattern. Unilateral (82%) involvement was more common than bilateral (18%) involvement. Among patients who received chest CT, 12 (92%) showed abnormalities, with bilateral (67%) and random (75%) involvement being more common. Ground-glass opacity (67%) and centrilobular nodules (58%) were the more common CT findings. Only a small number of patients were critically ill enough to undergo further radiologic evaluation as a result of pandemic (H1N1) 2009 virus infection, and most patients had normal chest radiographs. Unilateral airspace pneumonia was the most common abnormality in patients infected with pandemic (H1N1) 2009 virus.

  17. A polyvalent influenza A DNA vaccine induces heterologous immunity and protects pigs against pandemic A(H1N1)pdm09 virus infection

    DEFF Research Database (Denmark)

    Bragstad, Karoline; Vinner, Lasse; Hansen, Mette Sif

    2013-01-01

    seasonal and emerging influenza viruses. We have developed an alternative influenza vaccine based on DNA expressing selected influenza proteins of pandemic and seasonal origin. In the current study, we investigated the protection of a polyvalent influenza DNA vaccine approach in pigs. We immunised pigs...... intradermally with a combination of influenza DNA vaccine components based on the pandemic 1918 H1N1 (M and NP genes), pandemic 2009 H1N1pdm09 (HA and NA genes) and seasonal 2005 H3N2 genes (HA and NA genes) and investigated the protection against infection with virus both homologous and heterologous to the DNA...... of this DNA vaccine to limit virus shedding may have an impact on virus spread among pigs which could possibly extend to humans as well, thereby diminishing the risk for epidemics and pandemics to evolve....

  18. Protective efficacy of an inactivated Eurasian avian-like H1N1 swine influenza vaccine against homologous H1N1 and heterologous H1N1 and H1N2 viruses in mice.

    Science.gov (United States)

    Sui, Jinyu; Yang, Dawei; Qiao, Chuanling; Xu, Huiyang; Xu, Bangfeng; Wu, Yunpu; Yang, Huanliang; Chen, Yan; Chen, Hualan

    2016-07-19

    Eurasian avian-like H1N1 (EA H1N1) swine influenza viruses are prevalent in pigs in Europe and Asia, but occasionally cause human infection, which raises concern about their pandemic potential. Here, we produced a whole-virus inactivated vaccine with an EA H1N1 strain (A/swine/Guangxi/18/2011, SW/GX/18/11) and evaluated its efficacy against homologous H1N1 and heterologous H1N1 and H1N2 influenza viruses in mice. A strong humoral immune response, which we measured by hemagglutination inhibition (HI) and virus neutralization (VN), was induced in the vaccine-inoculated mice upon challenge. The inactivated SW/GX/18/11 vaccine provided complete protection against challenge with homologous SW/GX/18/11 virus in mice and provided effective protection against challenge with heterologous H1N1 and H1N2 viruses with distinctive genomic combinations. Our findings suggest that this EA H1N1 vaccine can provide protection against both homologous H1N1 and heterologous H1N1 or H1N2 virus infection. As such, it is an excellent vaccine candidate to prevent H1N1 swine influenza. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Vγ4+γδT Cells Aggravate Severe H1N1 Influenza Virus Infection-Induced Acute Pulmonary Immunopathological Injury via Secreting Interleukin-17A

    Directory of Open Access Journals (Sweden)

    Chunxue Xue

    2017-08-01

    Full Text Available The influenza A (H1N1 pdm09 virus remains a critical global health concern and causes high levels of morbidity and mortality. Severe acute lung injury (ALI and acute respiratory distress syndrome (ARDS are the major outcomes among severely infected patients. Our previous study found that interleukin (IL-17A production by humans or mice infected with influenza A (H1N1 pdm09 substantially contributes to ALI and subsequent morbidity and mortality. However, the cell types responsible for IL-17A production during the early stage of severe influenza A (H1N1 pdm09 infection remained unknown. In this study, a mouse model of severe influenza A (H1N1 pdm09 infection was established. Our results show that, in the lungs of infected mice, the percentage of γδT cells, but not the percentages of CD4+Th and CD8+Tc cells, gradually increased and peaked at 3 days post-infection (dpi. Further analysis revealed that the Vγ4+γδT subset, but not the Vγ1+γδT subset, was significantly increased among the γδT cells. At 3 dpi, the virus induced significant increases in IL-17A in the bronchoalveolar lavage fluid (BALF and serum. IL-17A was predominantly secreted by γδT cells (especially the Vγ4+γδT subset, but not CD4+Th and CD8+Tc cells at the early stage of infection, and IL-1β and/or IL-23 were sufficient to induce IL-17A production by γδT cells. In addition to secreting IL-17A, γδT cells secreted interferon (IFN-γ and expressed both an activation-associated molecule, natural killer group 2, member D (NKG2D, and an apoptosis-associated molecule, FasL. Depletion of γδT cells or the Vγ4+γδT subset significantly rescued the virus-induced weight loss and improved the survival rate by decreasing IL-17A secretion and reducing immunopathological injury. This study demonstrated that, by secreting IL-17A, lung Vγ4+γδT cells, at least, in part mediated influenza A (H1N1 pdm09-induced immunopathological injury. This mechanism might serve as a

  20. Prevalence and risk factors for H1N1 and H3N2 influenza A virus infections in Minnesota turkey premises.

    Science.gov (United States)

    Corzo, Cesar A; Gramer, Marie; Lauer, Dale; Davies, Peter R

    2012-09-01

    Influenza virus infections can cause respiratory and systemic disease of variable severity and also result in economic losses for the turkey industry. Several subtypes of influenza can infect turkeys, causing diverse clinical signs. Influenza subtypes of swine origin have been diagnosed in turkey premises; however, it is not known how common these infections are nor the likely routes of transmission. We conducted a cross-sectional study to estimate the prevalence of influenza viruses and examine factors associated with infection on Minnesota turkey premises. Results from influenza diagnostic tests and turkey and pig premise location data were obtained from the Minnesota Poultry Testing Laboratory and the Minnesota Board of Animal Health, respectively, from January 2007 to September 2008. Diagnostic data from 356 premises were obtained, of which 17 premises tested positive for antibodies to influenza A virus by agar gel immunodiffusion assay and were confirmed as either H1N1 or H3N2 influenza viruses by hemagglutination and neuraminidase inhibition assays. Influenza infection status was associated with proximity to pig premises and flock size. The latter had a sparing effect on influenza status. This study suggests that H1N1 and H3N2 influenza virus infections of turkey premises in Minnesota are an uncommon event. The route of influenza virus transmission could not be determined; however, the findings suggest that airborne transmission should be considered in future studies.

  1. Identification and Epidemiology of Severe Respiratory Disease due to Novel Swine-Origin Influenza A (H1N1 Virus Infection in Alberta

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    George Zahariadis

    2010-01-01

    Full Text Available BACKGROUND: In March 2009, global surveillance started detecting cases of influenza-like illness in Mexico. By mid-April 2009, two pediatric patients were identified in the United States who were confirmed to be infected by a novel influenza A (H1N1 strain. The present article describes the first identified severe respiratory infection and the first death associated with pandemic H1N1 (pH1N1 in Canada.

  2. Burden of pediatric influenza A virus infection post swine-flu H1N1 pandemic in Egypt.

    Science.gov (United States)

    Khattab, Adel; Shaheen, Malak; Kamel, Terez; El Faramay, Amel; El Rahman, Safaa Abd; Nabil, Dalia; Gouda, Mohamed

    2013-09-01

    To screen children with influenza like illness or with symptoms of acute respiratory tract infections for influenza A virus infection - post swine flu pandemic era - using rapid influenza diagnostic tests. During two years (2010 & 2011), 1 200 children with influenza like illness or acute respiratory tract infections (according to World Health Organization criteria) were recruited. Their ages ranged from 2-60 months. Nasopharyngeal aspirates specimens were collected from all children for rapid influenza A diagnostic test. Influenza A virus rapid test was positive in 47.5% of the children; the majority (89.6%) were presented with lower respiratory tract infections. Respiratory rate and temperature were significantly higher among positive rapid influenza test patients. Influenza A virus infection is still a major cause of respiratory tract infections in Egyptian children. It should be considered in all cases with cough and febrile episodes and influenza like symptoms even post swine flu pandemic. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  3. Sociodemographic factors and clinical conditions associated to hospitalization in influenza A (H1N1 2009 virus infected patients in Spain, 2009-2010.

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    Fernando González-Candelas

    Full Text Available The emergence and pandemic spread of a new strain of influenza A (H1N1 virus in 2009 resulted in a serious alarm in clinical and public health services all over the world. One distinguishing feature of this new influenza pandemic was the different profile of hospitalized patients compared to those from traditional seasonal influenza infections. Our goal was to analyze sociodemographic and clinical factors associated to hospitalization following infection by influenza A(H1N1 virus. We report the results of a Spanish nationwide study with laboratory confirmed infection by the new pandemic virus in a case-control design based on hospitalized patients. The main risk factors for hospitalization of influenza A (H1N1 2009 were determined to be obesity (BMI≥40, with an odds-ratio [OR] 14.27, hematological neoplasia (OR 10.71, chronic heart disease, COPD (OR 5.16 and neurological disease, among the clinical conditions, whereas low education level and some ethnic backgrounds (Gypsies and Amerinds were the sociodemographic variables found associated to hospitalization. The presence of any clinical condition of moderate risk almost triples the risk of hospitalization (OR 2.88 and high risk conditions raise this value markedly (OR 6.43. The risk of hospitalization increased proportionally when for two (OR 2.08 or for three or more (OR 4.86 risk factors were simultaneously present in the same patient. These findings should be considered when a new influenza virus appears in the human population.

  4. Alteration of protein levels during influenza virus H1N1 infection in host cells: a proteomic survey of host and virus reveals differential dynamics.

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    Susann Kummer

    Full Text Available We studied the dynamics of the proteome of influenza virus A/PR/8/34 (H1N1 infected Madin-Darby canine kidney cells up to 12 hours post infection by mass spectrometry based quantitative proteomics using the approach of stable isotope labeling by amino acids in cell culture (SILAC. We identified 1311 cell proteins and, apart from the proton channel M2, all major virus proteins. Based on their abundance two groups of virus proteins could be distinguished being in line with the function of the proteins in genesis and formation of new virions. Further, the data indicate a correlation between the amount of proteins synthesized and their previously determined copy number inside the viral particle. We employed bioinformatic approaches such as functional clustering, gene ontology, and pathway (KEGG enrichment tests to uncover co-regulated cellular protein sets, assigned the individual subsets to their biological function, and determined their interrelation within the progression of viral infection. For the first time we are able to describe dynamic changes of the cellular and, of note, the viral proteome in a time dependent manner simultaneously. Through cluster analysis, time dependent patterns of protein abundances revealed highly dynamic up- and/or down-regulation processes. Taken together our study provides strong evidence that virus infection has a major impact on the cell status at the protein level.

  5. Follow-up after acute respiratory distress syndrome caused by influenza a (H1N1 virus infection

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    Carlos Toufen Jr.

    2011-01-01

    Full Text Available BACKGROUND: There are no reports on the long-term follow-up of patients with swine-origin influenza A virus infection that progressed to acute respiratory distress syndrome. METHODS: Four patients were prospectively followed up with pulmonary function tests and high-resolution computed tomography for six months after admission to an intensive care unit. RESULTS: Pulmonary function test results assessed two months after admission to the intensive care unit showed reduced forced vital capacity in all patients and low diffusion capacity for carbon monoxide in two patients. At six months, pulmonary function test results were available for three patients. Two patients continued to have a restrictive pattern, and none of the patients presented with abnormal diffusion capacity for carbon monoxide. All of them had a diffuse ground-glass pattern on high-resolution computed tomography that improved after six months. CONCLUSIONS: Despite the marked severity of lung disease at admission, patients with acute respiratory distress syndrome caused by swine-origin influenza A virus infection presented a late but substantial recovery over six months of follow-up.

  6. The critical role of Notch ligand Delta-like 1 in the pathogenesis of influenza A virus (H1N1 infection.

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    Toshihiro Ito

    2011-11-01

    Full Text Available Influenza A viral infections have been identified as the etiologic agents for historic pandemics, and contribute to the annual mortality associated with acute viral pneumonia. While both innate and acquired immunity are important in combating influenza virus infection, the mechanism connecting these arms of the immune system remains unknown. Recent data have indicated that the Notch system is an important bridge between antigen-presenting cells (APCs and T cell communication circuits and plays a central role in driving the immune system to overcome disease. In the present study, we examine the role of Notch signaling during influenza H1N1 virus infection, focusing on APCs. We demonstrate here that macrophages, but not dendritic cells (DCs, increased Notch ligand Delta-like 1 (Dll1 expression following influenza virus challenge. Dll1 expression on macrophages was dependent on retinoic acid-inducible gene-I (RIG-I induced type-I IFN pathway, and not on the TLR3-TRIF pathway. We also found that IFNα-Receptor knockout mice failed to induce Dll1 expression on lung macrophages and had enhanced mortality during influenza virus infection. Our results further showed that specific neutralization of Dll1 during influenza virus challenge induced higher mortality, impaired viral clearance, and decreased levels of IFN-γ. In addition, we blocked Notch signaling by using γ-secretase inhibitor (GSI, a Notch signaling inhibitor. Intranasal administration of GSI during influenza infection also led to higher mortality, and higher virus load with excessive inflammation and an impaired production of IFN-γ in lungs. Moreover, Dll1 expression on macrophages specifically regulates IFN-γ levels from CD4(+and CD8(+T cells, which are important for anti-viral immunity. Together, the results of this study show that Dll1 positively influences the development of anti-viral immunity, and may provide mechanistic approaches for modifying and controlling the immune response

  7. miR-194 Inhibits Innate Antiviral Immunity by Targeting FGF2 in Influenza H1N1 Virus Infection

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    Keyu Wang

    2017-11-01

    Full Text Available Fibroblast growth factor 2 (FGF2 or basic FGF regulates a wide range of cell biological functions including proliferation, angiogenesis, migration, differentiation, and injury repair. However, the roles of FGF2 and the underlying mechanisms of action in influenza A virus (IAV-induced lung injury remain largely unexplored. In this study, we report that microRNA-194-5p (miR-194 expression is significantly decreased in A549 alveolar epithelial cells (AECs following infection with IAV/Beijing/501/2009 (BJ501. We found that miR-194 can directly target FGF2, a novel antiviral regulator, to suppress FGF2 expression at the mRNA and protein levels. Overexpression of miR-194 facilitated IAV replication by negatively regulating type I interferon (IFN production, whereas reintroduction of FGF2 abrogated the miR-194-induced effects on IAV replication. Conversely, inhibition of miR-194 alleviated IAV-induced lung injury by promoting type I IFN antiviral activities in vivo. Importantly, FGF2 activated the retinoic acid-inducible gene I signaling pathway, whereas miR-194 suppressed the phosphorylation of tank binding kinase 1 and IFN regulatory factor 3. Our findings suggest that the miR-194-FGF2 axis plays a vital role in IAV-induced lung injury, and miR-194 antagonism might be a potential therapeutic target during IAV infection.

  8. Effect of priming with H1N1 influenza viruses of variable antigenic distances on challenge with 2009 pandemic H1N1 virus.

    Science.gov (United States)

    O'Donnell, Christopher D; Wright, Amber; Vogel, Leatrice N; Wei, Chih-Jen; Nabel, Gary J; Subbarao, Kanta

    2012-08-01

    Compared to seasonal influenza viruses, the 2009 pandemic H1N1 (pH1N1) virus caused greater morbidity and mortality in children and young adults. People over 60 years of age showed a higher prevalence of cross-reactive pH1N1 antibodies, suggesting that they were previously exposed to an influenza virus or vaccine that was antigenically related to the pH1N1 virus. To define the basis for this cross-reactivity, ferrets were infected with H1N1 viruses of variable antigenic distance that circulated during different decades from the 1930s (Alaska/35), 1940s (Fort Monmouth/47), 1950s (Fort Warren/50), and 1990s (New Caledonia/99) and challenged with 2009 pH1N1 virus 6 weeks later. Ferrets primed with the homologous CA/09 or New Jersey/76 (NJ/76) virus served as a positive control, while the negative control was an influenza B virus that should not cross-protect against influenza A virus infection. Significant protection against challenge virus replication in the respiratory tract was observed in ferrets primed with AK/35, FM/47, and NJ/76; FW/50-primed ferrets showed reduced protection, and NC/99-primed ferrets were not protected. The hemagglutinins (HAs) of AK/35, FM/47, and FW/50 differ in the presence of glycosylation sites. We found that the loss of protective efficacy observed with FW/50 was associated with the presence of a specific glycosylation site. Our results suggest that changes in the HA occurred between 1947 and 1950, such that prior infection could no longer protect against 2009 pH1N1 infection. This provides a mechanistic understanding of the nature of serological cross-protection observed in people over 60 years of age during the 2009 H1N1 pandemic.

  9. Pathogenesis of infection with 2009 pandemic H1N1 influenza virus in isogenic guinea pigs after intranasal or intratracheal inoculation.

    Science.gov (United States)

    Wiersma, Lidewij C M; Vogelzang-van Trierum, Stella E; van Amerongen, Geert; van Run, Peter; Nieuwkoop, Nella J; Ladwig, Mechtild; Banneke, Stefanie; Schaefer, Hubert; Kuiken, Thijs; Fouchier, Ron A M; Osterhaus, Albert D M E; Rimmelzwaan, Guus F

    2015-03-01

    To elucidate the pathogenesis and transmission of influenza virus, the ferret model is typically used. To investigate protective immune responses, the use of inbred mouse strains has proven invaluable. Here, we describe a study with isogenic guinea pigs, which would uniquely combine the advantages of the mouse and ferret models for influenza virus infection. Strain 2 isogenic guinea pigs were inoculated with H1N1pdm09 influenza virus A/Netherlands/602/09 by the intranasal or intratracheal route. Viral replication kinetics were assessed by determining virus titers in nasal swabs and respiratory tissues, which were also used to assess histopathologic changes and the number of infected cells. In all guinea pigs, virus titers peaked in nasal secretions at day 2 after inoculation. Intranasal inoculation resulted in higher virus excretion via the nose and higher virus titers in the nasal turbinates than intratracheal inoculation. After intranasal inoculation, infectious virus was recovered only from nasal epithelium; after intratracheal inoculation, it was recovered also from trachea, lung, and cerebrum. Histopathologic changes corresponded with virus antigen distribution, being largely limited to nasal epithelium for intranasally infected guinea pigs and more widespread in the respiratory tract for intratracheally infected guinea pigs. In summary, isogenic guinea pigs show promise as a model to investigate the role of humoral and cell-mediated immunities to influenza and their effect on virus transmission. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  10. Factors associated with post-seasonal serological titer and risk factors for infection with the pandemic A/H1N1 virus in the French general population.

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    Nathanael Lapidus

    Full Text Available The CoPanFlu-France cohort of households was set up in 2009 to study the risk factors for infection by the pandemic influenza virus (H1N1pdm in the French general population. The authors developed an integrative data-driven approach to identify individual, collective and environmental factors associated with the post-seasonal serological H1N1pdm geometric mean titer, and derived a nested case-control analysis to identify risk factors for infection during the first season. This analysis included 1377 subjects (601 households. The GMT for the general population was 47.1 (95% confidence interval (CI: 45.1, 49.2. According to a multivariable analysis, pandemic vaccination, seasonal vaccination in 2009, recent history of influenza-like illness, asthma, chronic obstructive pulmonary disease, social contacts at school and use of public transports by the local population were associated with a higher GMT, whereas history of smoking was associated with a lower GMT. Additionally, young age at inclusion and risk perception of exposure to the virus at work were identified as possible risk factors, whereas presence of an air humidifier in the living room was a possible protective factor. These findings will be interpreted in light of the longitudinal analyses of this ongoing cohort.

  11. Polymorphism of HLA class I and class II alleles in influenza A(H1N1)pdm09 virus infected population of Assam, Northeast India.

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    Dutta, Mousumi; Dutta, Prafulla; Medhi, Subhash; Borkakoty, Biswajyoti; Biswas, Dipankar

    2018-05-01

    Human leucocyte antigen (HLA) represents one of the most highly polymorphic systems which plays a central role in the immune response. Genetic polymorphism of HLA in influenza A(H1N1)pdm09 infected population may be an important factor in disease progression and severity that needs further probing. In this study, a total of 110 Influenza like illness patients were recruited from the population of Assam, Northeast India, from which 35 cases infected by A(H1N1)pdm09 viruses and 35 controls were typed for HLA-A, B and DRB1 locus by PCR-SSP method. A total of seven alleles of HLA-A, 16 alleles of HLA-B, and 11 alleles of HLA-DRB1 locus were identified. The most common alleles within each locus in cases were HLA-A*11 (85.71%, P = 0.046), HLA-B*35 (25%, P = 0.0001), and HLA-DRB1*15 (49.35%,  P = 0.133) as compared to the controls, HLA-A*11 (40.82%), HLA-B*35 (0.00%), and HLA-DRB1*15 (67.53%). The frequency of HLA-A*11 and HLA-B*35 were significantly higher in cases as compared to the controls. In DRB1 locus, HLA-DRB1*10 was significantly higher in cases (20.78%, P = 0.005) than that of controls (0.00%). Whereas, HLA-DRB1*15 showed a higher frequency in controls than in cases. In addition, HLA-DRB3*01 (P = 0.053), DRB4*01 (P = 1.000), and DRB5*01(P = 0.591) were also identified along with HLA-DRB1 haplotype. From this preliminary study, it is suspected that there may be a role of HLA-A*11, HLA-B*35 and HLA-DRB1*10 in conferring susceptibility to influenza A(H1N1)pdm09 infection in the study population. A larger extended study on HLA polymorphism may explain the association between HLA and influenza A(H1N1)pdm09 infection and provide insights for HLA restricted peptide based vaccines. © 2018 Wiley Periodicals, Inc.

  12. The environmental deposition of influenza virus from patients infected with influenza A(H1N1)pdm09: Implications for infection prevention and control.

    Science.gov (United States)

    Killingley, Benjamin; Greatorex, Jane; Digard, Paul; Wise, Helen; Garcia, Fayna; Varsani, Harsha; Cauchemez, Simon; Enstone, Joanne E; Hayward, Andrew; Curran, Martin D; Read, Robert C; Lim, Wei S; Nicholson, Karl G; Nguyen-Van-Tam, Jonathan S

    2016-01-01

    In a multi-center, prospective, observational study over two influenza seasons, we sought to quantify and correlate the amount of virus recovered from the nares of infected subjects with that recovered from their immediate environment in community and hospital settings. We recorded the symptoms of adults and children with A(H1N1)pdm09 infection, took nasal swabs, and sampled touched surfaces and room air. Forty-two infected subjects were followed up. The mean duration of virus shedding was 6.2 days by PCR (Polymerase Chain Reaction) and 4.2 days by culture. Surface swabs were collected from 39 settings; 16 (41%) subject locations were contaminated with virus. Overall, 33 of the 671 (4.9%) surface swabs were PCR positive for influenza, of which two (0.3%) yielded viable virus. On illness Day 3, subjects yielding positive surface samples had significantly higher nasal viral loads (geometric mean ratio 25.7; 95% CI 1.75, 376.0, p=0.021) and a positive correlation (r=0.47, p=0.006) was observed between subject nasal viral loads and viral loads recovered from the surfaces around them. Room air was sampled in the vicinity of 12 subjects, and PCR positive samples were obtained for five (42%) samples. Influenza virus shed by infected subjects did not detectably contaminate the vast majority of surfaces sampled. We question the relative importance of the indirect contact transmission of influenza via surfaces, though our data support the existence of super-spreaders via this route. The air sampling results add to the accumulating evidence that supports the potential for droplet nuclei (aerosol) transmission of influenza. Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  13. Surveillance of illness associated with pandemic (H1N1) 2009 virus infection among adults using a global clinical site network approach: the INSIGHT FLU 002 and FLU 003 studies

    DEFF Research Database (Denmark)

    Dwyer, Dominic E; Nielsen, Henrik Ib

    2011-01-01

    The novel pandemic influenza A (H1H1) 2009 virus spread rapidly around the world in 2009. The paucity of prospective international epidemiologic data on predictors of clinical outcomes with pandemic (H1N1) 2009 virus infection stimulated the INSIGHT network, an international network of community...... and hospital-based investigators, to commence two worldwide clinical observational studies to describe pandemic (H1N1) 2009 virus activity. The purpose of these two studies was to estimate the percent of adult patients with illness due to laboratory-confirmed pandemic (H1N1) 2009 virus infection...

  14. Narcolepsy: Association with H1N1 Infection and Vaccination

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    Ji Hyun Song

    2016-12-01

    Full Text Available Epidemiological studies have demonstrated an association between H1N1 influenza infection and vaccinations. This article reviews the various studies, and suggests the biological mechanisms explaining why and how H1N1 influenza infection or vaccine stimulates the autoimmune response, thereby resulting in narcolepsy. Among the vaccines, the effect of Pandemrix was scrutinized more than other vaccines, due to its higher association with an increase of narcolepsy onset. The consequences of using other vaccines which contain same or different adjuvants as Pandemrix, were also analyzed.

  15. Protection of pigs against pandemic swine origin H1N1 influenza A virus infection by hemagglutinin- or neuraminidase-expressing attenuated pseudorabies virus recombinants.

    Science.gov (United States)

    Klingbeil, Katharina; Lange, Elke; Blohm, Ulrike; Teifke, Jens P; Mettenleiter, Thomas C; Fuchs, Walter

    2015-03-02

    Influenza is an important respiratory disease of pigs, and may lead to novel human pathogens like the 2009 pandemic H1N1 swine-origin influenza virus (SoIV). Therefore, improved influenza vaccines for pigs are required. Recently, we demonstrated that single intranasal immunization with a hemagglutinin (HA)-expressing pseudorabies virus recombinant of vaccine strain Bartha (PrV-Ba) protected pigs from H1N1 SoIV challenge (Klingbeil et al., 2014). Now we investigated enhancement of efficacy by prime-boost vaccination and/or intramuscular administration. Furthermore, a novel PrV-Ba recombinant expressing codon-optimized N1 neuraminidase (NA) was included. In vitro replication of this virus was only slightly affected compared to parental virus. Unlike HA, the abundantly expressed NA was efficiently incorporated into PrV particles. Immunization of pigs with the two PrV recombinants, either singly or in combination, induced B cell proliferation and the expected SoIV-specific antibodies, whose titers increased substantially after boost vaccination. After immunization of animals with either PrV recombinant H1N1 SoIV challenge virus replication was significantly reduced compared to PrV-Ba vaccinated or naïve controls. Protective efficacy of HA-expressing PrV was higher than of NA-expressing PrV, and not significantly enhanced by combination. Despite higher serum antibody titers obtained after intramuscular immunization, transmission of challenge virus to naïve contact animals was only prevented after intranasal prime-boost vaccination with HA-expressing PrV-Ba. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Distinct T and NK cell populations may serve as immune correlates of protection against symptomatic pandemic influenza A(H1N1 virus infection during pregnancy.

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    Miloje Savic

    Full Text Available Maternal influenza infection during pregnancy is associated with increased risk of morbidity and mortality. However, the link between the anti-influenza immune responses and health-related risks during infection is not well understood. We have analyzed memory T and NK cell mediated immunity (CMI responses in pandemic influenza A(H1N1pdm09 (pdm09 virus infected non-vaccinated pregnant women participating in the Norwegian Influenza Pregnancy Cohort (NorFlu. The cohort includes information on immunization, self-reported health and disease status, and biological samples (plasma and PBMC. Infected cases (N = 75 were defined by having a serum hemagglutination inhibition (HI titer > = 20 to influenza pdm09 virus at the time of delivery, while controls (N = 75 were randomly selected among non-infected pregnant women (HI titer <10. In ELISpot assays cases had higher frequencies of IFNγ+ CD8+ T cells responding to pdm09 virus or conserved CD8 T cell-restricted influenza A virus epitopes, compared to controls. Within this T cell population, frequencies of CD95+ late effector (CD45RA+CCR7- and naive (CD45RA+CCR7+ CD8+ memory T cells correlated inversely with self-reported influenza illness (ILI symptoms. ILI symptoms in infected women were also associated with lower numbers of poly-functional (IFNγ+TNFα+, IL2+IFNγ+, IL2+IFNγ+TNFα+ CD4+ T cells and increased frequencies of IFNγ+CD3-CD7+ NK cells compared to asymptomatic cases, or controls, after stimulation with the pdm09 virus. Taken together, virus specific and functionally distinct T and NK cell populations may serve as cellular immune correlates of clinical outcomes of pandemic influenza disease in pregnant women. Our results may provide information important for future universal influenza vaccine design.

  17. Distinct T and NK cell populations may serve as immune correlates of protection against symptomatic pandemic influenza A(H1N1) virus infection during pregnancy.

    Science.gov (United States)

    Savic, Miloje; Dembinski, Jennifer L; Laake, Ida; Hungnes, Olav; Cox, Rebecca; Oftung, Fredrik; Trogstad, Lill; Mjaaland, Siri

    2017-01-01

    Maternal influenza infection during pregnancy is associated with increased risk of morbidity and mortality. However, the link between the anti-influenza immune responses and health-related risks during infection is not well understood. We have analyzed memory T and NK cell mediated immunity (CMI) responses in pandemic influenza A(H1N1)pdm09 (pdm09) virus infected non-vaccinated pregnant women participating in the Norwegian Influenza Pregnancy Cohort (NorFlu). The cohort includes information on immunization, self-reported health and disease status, and biological samples (plasma and PBMC). Infected cases (N = 75) were defined by having a serum hemagglutination inhibition (HI) titer > = 20 to influenza pdm09 virus at the time of delivery, while controls (N = 75) were randomly selected among non-infected pregnant women (HI titer <10). In ELISpot assays cases had higher frequencies of IFNγ+ CD8+ T cells responding to pdm09 virus or conserved CD8 T cell-restricted influenza A virus epitopes, compared to controls. Within this T cell population, frequencies of CD95+ late effector (CD45RA+CCR7-) and naive (CD45RA+CCR7+) CD8+ memory T cells correlated inversely with self-reported influenza illness (ILI) symptoms. ILI symptoms in infected women were also associated with lower numbers of poly-functional (IFNγ+TNFα+, IL2+IFNγ+, IL2+IFNγ+TNFα+) CD4+ T cells and increased frequencies of IFNγ+CD3-CD7+ NK cells compared to asymptomatic cases, or controls, after stimulation with the pdm09 virus. Taken together, virus specific and functionally distinct T and NK cell populations may serve as cellular immune correlates of clinical outcomes of pandemic influenza disease in pregnant women. Our results may provide information important for future universal influenza vaccine design.

  18. Stability and infectivity of novel pandemic influenza A (H1N1) virus in blood-derived matrices under different storage conditions.

    Science.gov (United States)

    Wang, Xue; Zoueva, Olga; Zhao, Jiangqin; Ye, Zhiping; Hewlett, Indira

    2011-12-22

    Influenza A virus has been detected in the blood of some infected individuals, and may pose a safety concern for collection, handling and transport of specimens for epidemiological and public health investigations if infectious virus is present in samples. Furthermore the effect of storage on virus stability and infectivity has not been well studied. We examined the stability of novel pandemic influenza A (H1N1) virus RNA when the virus was stored in phosphate buffered saline (PBS), plasma, or buffy coated blood at either room temperature or 4°C using a sensitive Taqman RT-PCR assay. We also investigated virus infectivity using the EID(50) assay when virus was stored in PBS, plasma, or buffy coats isolated from blood at 4°C. Viral RNA stability was affected by the matrix used for storage. The recovery of viral RNA was highest when virus was stored in PBS with lower amounts being recovered from plasma and buffy coats at either room temperature or 4°C. Incubation time did not appear to be a major factor for viral RNA stability, although there was gradual decline after longer periods post-incubation. Both sample matrix and incubation time affected virus infectivity. The decay in virus infectivity was greatest in PBS followed by buffy coats and plasma. Virus infectivity was abolished in buffy coats at day 20 post-incubation when virus concentrations were low. These data indicate that encapsidated viral RNA was stable overall in all three liquid matrices at room temperature or 4°C although it was most stable in PBS; virus infectivity in buffy coats at 4°C decayed in a time dependent manner while it remained unchanged in plasma. These findings have implications for storage, handling and transport of blood derived samples from influenza patients for epidemiological and laboratory investigations. It should be noted that there is little known about influenza viremia, and whether influenza viruses can be transmitted by blood or blood derived samples.

  19. Stability and infectivity of novel pandemic influenza A (H1N1 virus in blood-derived matrices under different storage conditions

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    Wang Xue

    2011-12-01

    Full Text Available Abstract Background Influenza A virus has been detected in the blood of some infected individuals, and may pose a safety concern for collection, handling and transport of specimens for epidemiological and public health investigations if infectious virus is present in samples. Furthermore the effect of storage on virus stability and infectivity has not been well studied. Methods We examined the stability of novel pandemic influenza A (H1N1 virus RNA when the virus was stored in phosphate buffered saline (PBS, plasma, or buffy coated blood at either room temperature or 4°C using a sensitive Taqman RT-PCR assay. We also investigated virus infectivity using the EID50 assay when virus was stored in PBS, plasma, or buffy coats isolated from blood at 4°C. Results Viral RNA stability was affected by the matrix used for storage. The recovery of viral RNA was highest when virus was stored in PBS with lower amounts being recovered from plasma and buffy coats at either room temperature or 4°C. Incubation time did not appear to be a major factor for viral RNA stability, although there was gradual decline after longer periods post-incubation. Both sample matrix and incubation time affected virus infectivity. The decay in virus infectivity was greatest in PBS followed by buffy coats and plasma. Virus infectivity was abolished in buffy coats at day 20 post-incubation when virus concentrations were low. Conclusion These data indicate that encapsidated viral RNA was stable overall in all three liquid matrices at room temperature or 4°C although it was most stable in PBS; virus infectivity in buffy coats at 4°C decayed in a time dependent manner while it remained unchanged in plasma. These findings have implications for storage, handling and transport of blood derived samples from influenza patients for epidemiological and laboratory investigations. It should be noted that there is little known about influenza viremia, and whether influenza viruses can be

  20. La influenza A (H1N1: estado actual del conocimiento Influenza A (H1N1 virus: current information

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    Laura Margarita González Valdés

    2010-03-01

    Full Text Available Se revisó la bibliografía actualizada sobre el tema a partir de los principales buscadores, y reuniones internacionales realizadas sobre la pandemia de la influenza A (H1N1. Se tratan los aspectos relacionados con la historia, la aparición de la pandemia, la biología de la enfermedad, la epidemiología, el cuadro clínico, el tratamiento y el pronóstico y la prevención. La gripe A (H1N1 es una pandemia causada por una variante nueva del virus de la Influenza A que ha sufrido cambios antigénicos en la hemaglutinina y la neuraminidasa. Esto hace que la población sea altamente vulnerable a la infección y produce una sobrecarga temporal enorme a los servicios de salud. El virus se trasmite como otros virus Influenza. Su letalidad es similar a la de la influenza estacional, pero puede incrementarse en personas con factores de riesgo y en adultos jóvenes sanos. El asma y el embarazo parecen ser condiciones de base importantes para incrementar la severidad de la infección. Puede existir cierta protección por inmunidad cruzada con cepas que circularon en el pasado. El espectro clínico va desde personas asintomáticas hasta las formas graves que requieren internación en cuidados intensivos, con rápido deterioro hasta llegar a la insuficiencia respiratoria en un plazo de 24 horas. La vacunación durante la pandemia no parece ser suficientemente efectiva. Son necesarios antivirales (oseltamivir y zanamivir, y las medidas preventivas higiénico-sanitarias son muy eficaces.An updated review using the main search motors and international meetings already celebrated related to Influenza A H1N1 pandemics. Items related to the history, the appearance of the pandemics, the biology of the disease, its epidemiology, clinics, treatment, prognosis and prevention. Grippe A H1N1 is a pandemic caused by a new variant of the Influenza A virus that has suffered antigenic changes in haemaglutinin and neuraminidase. This turns populations more susceptible to

  1. Direct isolation of H1N2 recombinant virus from a throat swab of a patient simultaneously infected with H1N1 and H3N2 influenza A viruses.

    OpenAIRE

    Nishikawa, F; Sugiyama, T

    1983-01-01

    Two H1N2 recombinant viruses were isolated by a plaquing method from a throat swab of a patient who was simultaneously infected with H1N1 and H3N2 influenza viruses during the Tokyo epidemic of 1981. This is the first direct evidence that recombination of influenza viruses occurred in the human body.

  2. Natural co-infection of influenza A/H3N2 and A/H1N1pdm09 viruses resulting in a reassortant A/H3N2 virus.

    Science.gov (United States)

    Rith, Sareth; Chin, Savuth; Sar, Borann; Y, Phalla; Horm, Srey Viseth; Ly, Sovann; Buchy, Philippe; Dussart, Philippe; Horwood, Paul F

    2015-12-01

    Despite annual co-circulation of different subtypes of seasonal influenza, co-infections between different viruses are rarely detected. These co-infections can result in the emergence of reassortant progeny. We document the detection of an influenza co-infection, between influenza A/H3N2 with A/H1N1pdm09 viruses, which occurred in a 3 year old male in Cambodia during April 2014. Both viruses were detected in the patient at relatively high viral loads (as determined by real-time RT-PCR CT values), which is unusual for influenza co-infections. As reassortment can occur between co-infected influenza A strains we isolated plaque purified clonal viral populations from the clinical material of the patient infected with A/H3N2 and A/H1N1pdm09. Complete genome sequences were completed for 7 clonal viruses to determine if any reassorted viruses were generated during the influenza virus co-infection. Although most of the viral sequences were consistent with wild-type A/H3N2 or A/H1N1pdm09, one reassortant A/H3N2 virus was isolated which contained an A/H1N1pdm09 NS1 gene fragment. The reassortant virus was viable and able to infect cells, as judged by successful passage in MDCK cells, achieving a TCID50 of 10(4)/ml at passage number two. There is no evidence that the reassortant virus was transmitted further. The co-infection occurred during a period when co-circulation of A/H3N2 and A/H1N1pdm09 was detected in Cambodia. It is unclear how often influenza co-infections occur, but laboratories should consider influenza co-infections during routine surveillance activities. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Pre-infection of pigs with Mycoplasma hyopneumoniae modifies outcomes of infection with European swine influenza virus of H1N1, but not H1N2, subtype.

    Science.gov (United States)

    Deblanc, C; Gorin, S; Quéguiner, S; Gautier-Bouchardon, A V; Ferré, S; Amenna, N; Cariolet, R; Simon, G

    2012-05-25

    Swine influenza virus (SIV) and Mycoplasma hyopneumoniae (Mhp) are widespread in farms and are major pathogens involved in the porcine respiratory disease complex (PRDC). The aim of this experiment was to compare the pathogenicity of European avian-like swine H1N1 and European human-like reassortant swine H1N2 viruses in naïve pigs and in pigs previously infected with Mhp. Six groups of SPF pigs were inoculated intra-tracheally with either Mhp, or H1N1, or H1N2 or Mhp+H1N1 or Mhp+H1N2, both pathogens being inoculated at 21 days intervals in these two last groups. A mock-infected group was included. Although both SIV strains induced clinical signs when singly inoculated, results indicated that the H1N2 SIV was more pathogenic than the H1N1 virus, with an earlier shedding and a greater spread in lungs. Initial infection with Mhp before SIV inoculation increased flu clinical signs and pathogenesis (hyperthermia, loss of appetite, pneumonia lesions) due to the H1N1 virus but did not modify significantly outcomes of H1N2 infection. Thus, Mhp and SIV H1N1 appeared to act synergistically, whereas Mhp and SIV H1N2 would compete, as H1N2 infection led to the elimination of Mhp in lung diaphragmatic lobes. In conclusion, SIV would be a risk factor for the severity of respiratory disorders when associated with Mhp, depending on the viral subtype involved. This experimental model of coinfection with Mhp and avian-like swine H1N1 is a relevant tool for studying the pathogenesis of SIV-associated PRDC and testing intervention strategies for the control of the disease. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Serological response to the 2009 pandemic influenza A (H1N1 virus for disease diagnosis and estimating the infection rate in Thai population.

    Directory of Open Access Journals (Sweden)

    Hatairat Lerdsamran

    Full Text Available BACKGROUND: Individuals infected with the 2009 pandemic virus A(H1N1 developed serological response which can be measured by hemagglutination-inhibition (HI and microneutralization (microNT assays. METHODOLOGY/PRINCIPAL FINDINGS: MicroNT and HI assays for specific antibody to the 2009 pandemic virus were conducted in serum samples collected at the end of the first epidemic wave from various groups of Thai people: laboratory confirmed cases, blood donors and health care workers (HCW in Bangkok and neighboring province, general population in the North and the South, as well as archival sera collected at pre- and post-vaccination from vaccinees who received influenza vaccine of the 2006 season. This study demonstrated that goose erythrocytes yielded comparable HI antibody titer as compared to turkey erythrocytes. In contrast to the standard protocol, our investigation found out the necessity to eliminate nonspecific inhibitor present in the test sera by receptor destroying enzyme (RDE prior to performing microNT assay. The investigation in pre-pandemic serum samples showed that HI antibody was more specific to the 2009 pandemic virus than NT antibody. Based on data from pre-pandemic sera together with those from the laboratory confirmed cases, HI antibody titers ≥ 40 for adults and ≥ 20 for children could be used as the cut-off level to differentiate between the individuals with or without past infection by the 2009 pandemic virus. CONCLUSIONS/SIGNIFICANCE: Based on the cut-off criteria, the infection rates of 7 and 12.8% were estimated in blood donors and HCW, respectively after the first wave of the 2009 influenza pandemic. Among general population, the infection rate of 58.6% was found in children versus 3.1% in adults.

  5. The Neurological Manifestations of H1N1 Influenza Infection; Diagnostic Challenges and Recommendations

    Directory of Open Access Journals (Sweden)

    Ali Akbar Asadi-Pooya

    2011-03-01

    Full Text Available Background: World Health Organization declared pandemic phase of human infection with novel influenza A (H1N1 in April 2009. There are very few reports about the neurological complications of H1N1 virus infection in the literature. Occasionally, these complications are severe and even fatal in some individuals. The aims of this study were to report neurological complaints and/or complications associated with H1N1 virus infection. Methods: The medical files of all patients with H1N1 influenza infection admitted to a specified hospital in the city of Shiraz, Iran from October through November 2009 were reviewed. More information about the patients were obtained by phone calls to the patients or their care givers. All patients had confirmed H1N1 virus infection with real-time PCR assay. Results: Fifty-five patients with H1N1 infection were studied. Twenty-three patients had neurological signs and/or symptoms. Mild neurological complaints may be reported in up to 42% of patients infected by H1N1 virus. Severe neurological complications occurred in 9% of the patients. The most common neurological manifestations were headache, numbness and paresthesia, drowsiness and coma. One patient had a Guillain-Barre syndrome-like illness, and died in a few days. Another patient had focal status epilepticus and encephalopathy. Conclusions: The H1N1 infection seems to have been quite mild with a self-limited course in much of the world, yet there appears to be a subset, which is severely affected. We recommend performing diagnostic tests for H1N1influenza virus in all patients with respiratory illness and neurological signs/symptoms. We also recommend initiating treatment with appropriate antiviral drugs as soon as possible in those with any significant neurological presentation accompanied with respiratory illness and flu-like symptoms

  6. Metabolic pathways of lung inflammation revealed by high-resolution metabolomics (HRM) of H1N1 influenza virus infection in mice.

    Science.gov (United States)

    Chandler, Joshua D; Hu, Xin; Ko, Eun-Ju; Park, Soojin; Lee, Young-Tae; Orr, Michael; Fernandes, Jolyn; Uppal, Karan; Kang, Sang-Moo; Jones, Dean P; Go, Young-Mi

    2016-11-01

    Influenza is a significant health concern worldwide. Viral infection induces local and systemic activation of the immune system causing attendant changes in metabolism. High-resolution metabolomics (HRM) uses advanced mass spectrometry and computational methods to measure thousands of metabolites inclusive of most metabolic pathways. We used HRM to identify metabolic pathways and clusters of association related to inflammatory cytokines in lungs of mice with H1N1 influenza virus infection. Infected mice showed progressive weight loss, decreased lung function, and severe lung inflammation with elevated cytokines [interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ] and increased oxidative stress via cysteine oxidation. HRM showed prominent effects of influenza virus infection on tryptophan and other amino acids, and widespread effects on pathways including purines, pyrimidines, fatty acids, and glycerophospholipids. A metabolome-wide association study (MWAS) of the aforementioned inflammatory cytokines was used to determine the relationship of metabolic responses to inflammation during infection. This cytokine-MWAS (cMWAS) showed that metabolic associations consisted of distinct and shared clusters of 396 metabolites highly correlated with inflammatory cytokines. Strong negative associations of selected glycosphingolipid, linoleate, and tryptophan metabolites with IFN-γ contrasted strong positive associations of glycosphingolipid and bile acid metabolites with IL-1β, TNF-α, and IL-10. Anti-inflammatory cytokine IL-10 had strong positive associations with vitamin D, purine, and vitamin E metabolism. The detailed metabolic interactions with cytokines indicate that targeted metabolic interventions may be useful during life-threatening crises related to severe acute infection and inflammation. Copyright © 2016 the American Physiological Society.

  7. Characteristics of atopic children with pandemic H1N1 influenza viral infection: pandemic H1N1 influenza reveals 'occult' asthma of childhood.

    Science.gov (United States)

    Hasegawa, Shunji; Hirano, Reiji; Hashimoto, Kunio; Haneda, Yasuhiro; Shirabe, Komei; Ichiyama, Takashi

    2011-02-01

    The number of human cases of pandemic H1N1 influenza viral infection has increased in Japan since April 2009, as it has worldwide. This virus is widespread in the Yamaguchi prefecture in western Japan, where most infected children exhibited respiratory symptoms. Bronchial asthma is thought to be one of the risk factors that exacerbate respiratory symptoms of pandemic H1N1-infected patients, but the pathogenesis remains unclear. We retrospectively investigated the records of 33 children with pandemic H1N1 influenza viral infection who were admitted to our hospital between October and December 2009 and analyzed their clinical features. The percentage of children with asthma attack, with or without abnormal findings on chest radiographs (pneumonia, atelectasis, etc.), caused by pandemic H1N1 influenza infection was significantly higher than that of children with asthma attack and 2008-2009 seasonal influenza infection. Of the 33 children in our study, 22 (66.7%) experienced an asthma attack. Among these children, 20 (90.9%) did not receive long-term management for bronchial asthma, whereas 7 (31.8%) were not diagnosed with bronchial asthma and had experienced their first asthma attack. However, the severity of the attack did not correlate with the severity of the pulmonary complications of pandemic H1N1 influenza viral infection. The pandemic H1N1 influenza virus greatly increases the risk of lower respiratory tract complications such as asthma attack, pneumonia, and atelectasis, when compared to the seasonal influenza virus. Furthermore, our results suggest that pandemic H1N1 influenza viral infection can easily induce a severe asthma attack, pneumonia, and atelectasis in atopic children without any history of either an asthma attack or asthma treatment. © 2011 John Wiley & Sons A/S.

  8. High-resolution computed tomography findings of swine-origin influenza A (H1N1) virus (S-OIV) infection: comparison with scrub typhus

    International Nuclear Information System (INIS)

    Jo, Bang Sil; Lee, In Jae; Lee, Kwanseop; Im, Hyoung June

    2012-01-01

    Background. Swine-origin influenza A (H1N1) virus (S-OIV) infection and scrub typhus, also known as tsutsugamushi disease can manifest as acute respiratory illnesses, particularly during the late fall or early winter, with similar radiographic findings, such as a predominance of ground-glass opacity (GGO). Purpose. To differentiate S-OIV infection from scrub typhus using high-resolution computed tomography (HRCT). Material and Methods. We retrospectively reviewed the HRCT findings of 14 patients with S-OIV infection and 10 patients with scrub typhus. We assessed the location, cross-sectional distribution, and the presence of a peribronchovascular distribution of GGO and consolidations on HRCT. We also assessed the presence of interlobular septal thickening, bronchial wall thickening, pneumothorax, pneumomediastinum, pleural effusion, and mediastinal or axillary lymph node enlargement. Results. Scrub typhus was more common than S-OIV in elderly patients (P < 0.001). The monthly incidences of S-OIV and scrub typhus infection reached a peak between October and November. About 86% of S-OIV patients and 80% of scrub typhus patients presented with GGO. About 67% of the GGO lesions in S-OIV had a peribronchovascular distribution, but this was absent in scrub typhus (P = 0.005). Consolidation (93% vs. 10%, P < 0.001) and bronchial wall thickening (43% vs. 0%, P = 0.024) were more frequent in S-OIV infection than scrub typhus. Interlobular septal thickening (90% vs. 36%, P = 0.013) and axillary lymphadenopathy (90% vs. 0%, P < 0.001) were more common in scrub typhus than S-OIV infection. Conclusion. There was considerable overlap in HRCT findings between S-OIV infection and scrub typhus. However, S-OIV showed a distinctive peribronchovascular distribution of GGO lesions. Consolidation and bronchial wall thickening were seen more frequently in S-OIV infection, whereas interlobular septal thickening and axillary lymphadenopathy were more common in scrub typhus. Thus, CT could

  9. High-resolution computed tomography findings of swine-origin influenza A (H1N1) virus (S-OIV) infection: comparison with scrub typhus

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Bang Sil; Lee, In Jae; Lee, Kwanseop [Dept. of Radiology, Hallym Univ. College of Medicine, Seoul (Korea, Republic of)], E-mail: ijlee2003@medimail.co.kr; Im, Hyoung June [Dept. of Occupational Medicine, Hallym Univ. College of Medicine, Seoul (Korea, Republic of)

    2012-07-15

    Background. Swine-origin influenza A (H1N1) virus (S-OIV) infection and scrub typhus, also known as tsutsugamushi disease can manifest as acute respiratory illnesses, particularly during the late fall or early winter, with similar radiographic findings, such as a predominance of ground-glass opacity (GGO). Purpose. To differentiate S-OIV infection from scrub typhus using high-resolution computed tomography (HRCT). Material and Methods. We retrospectively reviewed the HRCT findings of 14 patients with S-OIV infection and 10 patients with scrub typhus. We assessed the location, cross-sectional distribution, and the presence of a peribronchovascular distribution of GGO and consolidations on HRCT. We also assessed the presence of interlobular septal thickening, bronchial wall thickening, pneumothorax, pneumomediastinum, pleural effusion, and mediastinal or axillary lymph node enlargement. Results. Scrub typhus was more common than S-OIV in elderly patients (P < 0.001). The monthly incidences of S-OIV and scrub typhus infection reached a peak between October and November. About 86% of S-OIV patients and 80% of scrub typhus patients presented with GGO. About 67% of the GGO lesions in S-OIV had a peribronchovascular distribution, but this was absent in scrub typhus (P = 0.005). Consolidation (93% vs. 10%, P < 0.001) and bronchial wall thickening (43% vs. 0%, P = 0.024) were more frequent in S-OIV infection than scrub typhus. Interlobular septal thickening (90% vs. 36%, P = 0.013) and axillary lymphadenopathy (90% vs. 0%, P < 0.001) were more common in scrub typhus than S-OIV infection. Conclusion. There was considerable overlap in HRCT findings between S-OIV infection and scrub typhus. However, S-OIV showed a distinctive peribronchovascular distribution of GGO lesions. Consolidation and bronchial wall thickening were seen more frequently in S-OIV infection, whereas interlobular septal thickening and axillary lymphadenopathy were more common in scrub typhus. Thus, CT could

  10. Cross-protection against European swine influenza viruses in the context of infection immunity against the 2009 pandemic H1N1 virus: studies in the pig model of influenza.

    Science.gov (United States)

    Qiu, Yu; De Hert, Karl; Van Reeth, Kristien

    2015-09-24

    Pigs are natural hosts for the same influenza virus subtypes as humans and are a valuable model for cross-protection studies with influenza. In this study, we have used the pig model to examine the extent of virological protection between a) the 2009 pandemic H1N1 (pH1N1) virus and three different European H1 swine influenza virus (SIV) lineages, and b) these H1 viruses and a European H3N2 SIV. Pigs were inoculated intranasally with representative strains of each virus lineage with 6- and 17-week intervals between H1 inoculations and between H1 and H3 inoculations, respectively. Virus titers in nasal swabs and/or tissues of the respiratory tract were determined after each inoculation. There was substantial though differing cross-protection between pH1N1 and other H1 viruses, which was directly correlated with the relatedness in the viral hemagglutinin (HA) and neuraminidase (NA) proteins. Cross-protection against H3N2 was almost complete in pigs with immunity against H1N2, but was weak in H1N1/pH1N1-immune pigs. In conclusion, infection with a live, wild type influenza virus may offer substantial cross-lineage protection against viruses of the same HA and/or NA subtype. True heterosubtypic protection, in contrast, appears to be minimal in natural influenza virus hosts. We discuss our findings in the light of the zoonotic and pandemic risks of SIVs.

  11. Linear DNA vaccine prepared by large-scale PCR provides protective immunity against H1N1 influenza virus infection in mice.

    Science.gov (United States)

    Wang, Fei; Chen, Quanjiao; Li, Shuntang; Zhang, Chenyao; Li, Shanshan; Liu, Min; Mei, Kun; Li, Chunhua; Ma, Lixin; Yu, Xiaolan

    2017-06-01

    Linear DNA vaccines provide effective vaccination. However, their application is limited by high cost and small scale of the conventional polymerase chain reaction (PCR) generally used to obtain sufficient amounts of DNA effective against epidemic diseases. In this study, a two-step, large-scale PCR was established using a low-cost DNA polymerase, RKOD, expressed in Pichia pastoris. Two linear DNA vaccines encoding influenza H1N1 hemagglutinin (HA) 1, LEC-HA, and PTO-LEC-HA (with phosphorothioate-modified primers), were produced by the two-step PCR. Protective effects of the vaccines were evaluated in a mouse model. BALB/c mice were immunized three times with the vaccines or a control DNA fragment. All immunized animals were challenged by intranasal administration of a lethal dose of influenza H1N1 virus 2 weeks after the last immunization. Sera of the immunized animals were tested for the presence of HA-specific antibodies, and the total IFN-γ responses induced by linear DNA vaccines were measured. The results showed that the DNA vaccines but not the control DNA induced strong antibody and IFN-γ responses. Additionally, the PTO-LEC-HA vaccine effectively protected the mice against the lethal homologous mouse-adapted virus, with a survival rate of 100% versus 70% in the LEC-HA-vaccinated group, showing that the PTO-LEC-HA vaccine was more effective than LEC-HA. In conclusion, the results indicated that the linear H1N1 HA-coding DNA vaccines induced significant immune responses and protected mice against a lethal virus challenge. Thus, the low-cost, two-step, large-scale PCR can be considered a potential tool for rapid manufacturing of linear DNA vaccines against emerging infectious diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Infecção pelo vírus Influenza A (H1N1 de origem suína: como reconhecer, diagnosticar e prevenir How to prevent, recognize and diagnose infection with the swine-origin Influenza A (H1N1 virus in humans

    Directory of Open Access Journals (Sweden)

    Alcyone Artioli Machado

    2009-05-01

    Full Text Available Em março de 2009, houve o início de uma epidemia de gripe no México que, em pouco tempo, levou ao surgimento de casos semelhantes em outros países, alertando as autoridades sanitárias para o risco de uma pandemia. Neste artigo, descrevemos os principais sinais e sintomas da infecção pelo vírus Influenza A (H1N1 de origem suína, as medidas a serem tomadas para os casos suspeitos ou confirmados e como proceder em relação aos contactantes. Comentamos também quais drogas são utilizadas para o tratamento e profilaxia.In March of 2009, a flu epidemic began in Mexico. Shortly thereafter, similar cases appeared in other countries, alerting authorities to the risk of a pandemic. This article details the principal signs and symptoms of infection with the swine-origin Influenza A (H1N1 virus. In addition, the measures to be taken in suspected or confirmed cases are addressed, as are the procedures to follow in relation to contacts. Furthermore, the drugs used in the prophylaxis against and the treatment of infection with the H1N1 virus are described.

  13. Comparative analyses of pandemic H1N1 and seasonal H1N1, H3N2, and influenza B infections depict distinct clinical pictures in ferrets.

    Directory of Open Access Journals (Sweden)

    Stephen S H Huang

    Full Text Available Influenza A and B infections are a worldwide health concern to both humans and animals. High genetic evolution rates of the influenza virus allow the constant emergence of new strains and cause illness variation. Since human influenza infections are often complicated by secondary factors such as age and underlying medical conditions, strain or subtype specific clinical features are difficult to assess. Here we infected ferrets with 13 currently circulating influenza strains (including strains of pandemic 2009 H1N1 [H1N1pdm] and seasonal A/H1N1, A/H3N2, and B viruses. The clinical parameters were measured daily for 14 days in stable environmental conditions to compare clinical characteristics. We found that H1N1pdm strains had a more severe physiological impact than all season strains where pandemic A/California/07/2009 was the most clinically pathogenic pandemic strain. The most serious illness among seasonal A/H1N1 and A/H3N2 groups was caused by A/Solomon Islands/03/2006 and A/Perth/16/2009, respectively. Among the 13 studied strains, B/Hubei-Wujiagang/158/2009 presented the mildest clinical symptoms. We have also discovered that disease severity (by clinical illness and histopathology correlated with influenza specific antibody response but not viral replication in the upper respiratory tract. H1N1pdm induced the highest and most rapid antibody response followed by seasonal A/H3N2, seasonal A/H1N1 and seasonal influenza B (with B/Hubei-Wujiagang/158/2009 inducing the weakest response. Our study is the first to compare the clinical features of multiple circulating influenza strains in ferrets. These findings will help to characterize the clinical pictures of specific influenza strains as well as give insights into the development and administration of appropriate influenza therapeutics.

  14. Involvement of the different lung compartments in the pathogenesis of pH1N1 influenza virus infection in ferrets.

    Science.gov (United States)

    Vidaña, Beatriz; Martínez, Jorge; Martorell, Jaime; Montoya, María; Córdoba, Lorena; Pérez, Mónica; Majó, Natàlia

    2016-11-08

    Severe cases after pH1N1 infection are consequence of interstitial pneumonia triggered by alveolar viral replication and an exacerbated host immune response, characterized by the up-regulation of pro-inflammatory cytokines and the influx of inflammatory leukocytes to the lungs. Different lung cell populations have been suggested as culprits in the unregulated innate immune responses observed in these cases. This study aims to clarify this question by studying the different induction of innate immune molecules by the distinct lung anatomic compartments (vascular, alveolar and bronchiolar) of ferrets intratracheally infected with a human pH1N1 viral isolate, by means of laser microdissection techniques. The obtained results were then analysed in relation to viral quantification in the different anatomic areas and the histopathological lesions observed. More severe lung lesions were observed at 24 h post infection (hpi) correlating with viral antigen detection in bronchiolar and alveolar epithelial cells. However, high levels of viral RNA were detected in all anatomic compartments throughout infection. Bronchiolar areas were the first source of IFN-α and most pro-inflammatory cytokines, through the activation of RIG-I. In contrast, vascular areas contributed with the highest induction of CCL2 and other pro-inflammatory cytokines, through the activation of TLR3.

  15. H1N1 infection in emergency surgery: A cautionary tale.

    LENUS (Irish Health Repository)

    Galbraith, J G

    2010-01-01

    Pandemic 2009 influenza A H1N1 has spread rapidly since its first report in Mexico in March 2009. This is the first influenza pandemic in over 40 years and it atypically affects previously healthy young adults, with higher rates of morbidity and mortality. The medical literature has been inundated with reports of H1N1 infection, the majority found in critical care and internal medicine journals with a relative paucity in the surgical literature. Despite this, it remains an important entity that can impact greatly on acute surgical emergencies. We present a case of previously healthy 31-year-old male who underwent open appendectomy. His post-operative recovery was complicated by acute respiratory distress syndrome secondary to H1N1 infection. This case report highlights the impact that H1N1 virus can have on acute surgical emergencies and how it can complicate the post-operative course.

  16. Molecular characterization of pandemic H1N1 influenza viruses isolated from turkeys and pathogenicity of a human pH1N1 isolate in turkeys.

    Science.gov (United States)

    Berhane, Yohannes; Ojkic, Davor; Neufeld, James; Leith, Marsha; Hisanaga, Tamiko; Kehler, Helen; Ferencz, Arpad; Wojcinski, Helen; Cottam-Birt, Colleen; Suderman, Matthew; Handel, Katherine; Alexandersen, Soren; Pasick, John

    2010-12-01

    Suspected human-to-animal transmission of the 2009 pandemic H1N1 (pH1N1) virus has been reported in several animal species, including pigs, dogs, cats, ferrets, and turkeys. In this study we describe the genetic characterization of pH1N1 viruses isolated from breeder turkeys that was associated with a progressive drop in egg production. Sequence analysis of all eight gene segments from three viruses isolated from this outbreak demonstrated homology with other human and swine pH1N1 isolates. The susceptibility of turkeys to a human pH1N1 isolate was further evaluated experimentally. The 50% turkey infectious dose (TID50) for the human isolate A/Mexico/LnDRE/4487/2009 was determined by inoculating groups of 8-10-week-old turkeys with serial 10-fold dilutions of virus by oronasal and cloacal routes. We estimated the TID50 to be between 1 x 10(5) and 1 x 10(6) TCID50. The pathogenesis of pH1N1 in oronasally or cloacally inoculated juvenile turkeys was also examined. None of the turkeys exhibited clinical signs, and no significant difference in virus shedding or seroconversion was observed between the two inoculation groups. More than 50% of the turkeys in both oronasal and cloacal groups shed virus beginning at 2 days postinoculation (dpi). All birds that actively shed virus seroconverted by 14 dpi. Virus antigen was demonstrated by immunohistochemistry in the cecal tonsils and bursa of Fabricius in two of the birds that were infected by the cloacal route. Virus transmission to naive contact turkeys was at best doubtful. This report provides additional evidence that pH1N1 can cross the species barrier and cause disease outbreaks in domestic turkeys. However, it appears that the reproductive status of the host as well as environmental factors such as concurrent infections, stress, the presence or absence of litter, and stocking density may also contribute to efficient infection and transmission of this agent.

  17. Clinical profile and predictors of mortality of severe pandemic (H1N1 2009 virus infection needing intensive care: A multi-centre prospective study from South India

    Directory of Open Access Journals (Sweden)

    Kartik Ramakrishna

    2012-01-01

    Full Text Available Background: This multi-center study from India details the profile and outcomes of patients admitted to the intensive care unit (ICU with pandemic Influenza A (H1N1 2009 virus [P(H1N12009v] infection. Materials and Methods: Over 4 months, adult patients diagnosed to have P(H1N12009v infection by real-time RT-PCR of respiratory specimens and requiring ICU admission were followed up until death or hospital discharge. Sequential organ failure assessment (SOFA scores were calculated daily. Results: Of the 1902 patients screened, 464 (24.4% tested positive for P(H1N12009v; 106 (22.8% patients aged 35±11.9 (mean±SD years required ICU admission 5.8±2.7 days after onset of illness. Common symptoms were fever (96.2%, cough (88.7%, and breathlessness (85.9%. The admission APACHE-II and SOFA scores were 14.4±6.5 and 5.5±3.1, respectively. Ninety-six (90.6% patients required ventilation for 10.1±7.5 days. Of these, 34/96 (35.4% were non-invasively ventilated; 16/34 were weaned successfully whilst 18/34 required intubation. Sixteen patients (15.1% needed dialysis. The duration of hospitalization was 14.0±8.0 days. Hospital mortality was 49%. Mortality in pregnant/puerperal women was 52.6% (10/19. Patients requiring invasive ventilation at admission had a higher mortality than those managed with non-invasive ventilation and those not requiring ventilation (44/62 vs. 8/44, P<0.001. Need for dialysis was independently associated with mortality (P=0.019. Although admission APACHE-II and SOFA scores were significantly (P<0.02 higher in non-survivors compared with survivors on univariate analysis, individually, neither were predictive on multivariate analysis. Conclusions: In our setting, a high mortality was observed in patients admitted to ICU with severe P(H1N12009v infection. The need for invasive ventilation and dialysis were associated with a poor outcome.

  18. Functional Evolution of Influenza Virus NS1 Protein in Currently Circulating Human 2009 Pandemic H1N1 Viruses.

    Science.gov (United States)

    Clark, Amelia M; Nogales, Aitor; Martinez-Sobrido, Luis; Topham, David J; DeDiego, Marta L

    2017-09-01

    In 2009, a novel H1N1 influenza virus emerged in humans, causing a global pandemic. It was previously shown that the NS1 protein from this human 2009 pandemic H1N1 (pH1N1) virus was an effective interferon (IFN) antagonist but could not inhibit general host gene expression, unlike other NS1 proteins from seasonal human H1N1 and H3N2 viruses. Here we show that the NS1 protein from currently circulating pH1N1 viruses has evolved to encode 6 amino acid changes (E55K, L90I, I123V, E125D, K131E, and N205S) with respect to the original protein. Notably, these 6 residue changes restore the ability of pH1N1 NS1 to inhibit general host gene expression, mainly by their ability to restore binding to the cellular factor CPSF30. This is the first report describing the ability of the pH1N1 NS1 protein to naturally acquire mutations that restore this function. Importantly, a recombinant pH1N1 virus containing these 6 amino acid changes in the NS1 protein (pH1N1/NSs-6mut) inhibited host IFN and proinflammatory responses to a greater extent than that with the parental virus (pH1N1/NS1-wt), yet virus titers were not significantly increased in cell cultures or in mouse lungs, and the disease was partially attenuated. The pH1N1/NSs-6mut virus grew similarly to pH1N1/NSs-wt in mouse lungs, but infection with pH1N1/NSs-6mut induced lower levels of proinflammatory cytokines, likely due to a general inhibition of gene expression mediated by the mutated NS1 protein. This lower level of inflammation induced by the pH1N1/NSs-6mut virus likely accounts for the attenuated disease phenotype and may represent a host-virus adaptation affecting influenza virus pathogenesis. IMPORTANCE Seasonal influenza A viruses (IAVs) are among the most common causes of respiratory infections in humans. In addition, occasional pandemics are caused when IAVs circulating in other species emerge in the human population. In 2009, a swine-origin H1N1 IAV (pH1N1) was transmitted to humans, infecting people then and up

  19. The seroprevalence of pandemic influenza H1N1 (2009 virus in China.

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    Cuiling Xu

    2011-04-01

    Full Text Available Mainland China experienced pandemic influenza H1N1 (2009 virus (pH1N1 with peak activity during November-December 2009. To understand the geographic extent, risk factors, and attack rate of pH1N1 infection in China we conducted a nationwide serological survey to determine the prevalence of antibodies to pH1N1.Stored serum samples (n = 2,379 collected during 2006-2008 were used to estimate baseline serum reactogenicity to pH1N1. In January 2010, we used a multistage-stratified random sampling method to select 50,111 subjects who met eligibility criteria and collected serum samples and administered a standardized questionnaire. Antibody response to pH1N1 was measured using haemagglutination inhibition (HI assay and the weighted seroprevalence was calculated using the Taylor series linearization method. Multivariable logistic regression analyses were used to examine risk factors for pH1N1 seropositivity. Baseline seroprevalence of pH1N1 antibody (HI titer ≥40 was 1.2%. The weighted seroprevalence of pH1N1 among the Chinese population was 21.5%(vaccinated: 62.0%; unvaccinated: 17.1%. Among unvaccinated participants, those aged 6-15 years (32.9% and 16-24 years (30.3% had higher seroprevalence compared with participants aged 25-59 years (10.7% and ≥60 years (9.9%, P<0.0001. Children in kindergarten and students had higher odds of seropositivity than children in family care (OR: 1.36 and 2.05, respectively. We estimated that 207.7 million individuals (15.9% experienced pH1N1 infection in China.The Chinese population had low pre-existing immunity to pH1N1 and experienced a relatively high attack rate in 2009 of this virus. We recommend routine control measures such as vaccination to reduce transmission and spread of seasonal and pandemic influenza viruses.

  20. Dual Infection of Novel Influenza Viruses A/H1N1 and A/H3N2 in a Cluster of Cambodian Patients

    Science.gov (United States)

    2011-01-01

    influenza viruses as well as the avian influenza virus A/H5N1...on full genome sequencing. This incident confirms dual influenza virus infections and highlights the risk of zoonotic and seasonal influenza viruses ...North American swine influenza viruses , North American avian influenza viruses , human influenza viruses , and a Eurasian swine influenza virus . 18

  1. Susceptibility of turkeys to pandemic-H1N1 virus by reproductive tract insemination

    Directory of Open Access Journals (Sweden)

    Suarez David L

    2010-02-01

    Full Text Available Abstract The current pandemic influenza A H1N1 2009 (pH1N1 was first recognized in humans with acute respiratory diseases in April 2009 in Mexico, in swine in Canada in June, 2009 with respiratory disease, and in turkeys in Chile in June 2009 with a severe drop in egg production. Several experimental studies attempted to reproduce the disease in turkeys, but failed to produce respiratory infection in turkeys using standard inoculation routes. We demonstrated that pH1N1 virus can infect the reproductive tract of turkey hens after experimental intrauterine inoculation, causing decreased egg production. This route of exposure is realistic in modern turkey production because turkey hens are handled once a week for intrauterine insemination in order to produce fertile eggs. This understanding of virus exposure provides an improved understanding of the pathogenesis of the disease and can improve poultry husbandry to prevent disease outbreaks.

  2. Effect of the novel influenza A (H1N1 virus in the human immune system.

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    Evangelos J Giamarellos-Bourboulis

    Full Text Available BACKGROUND: The pandemic by the novel H1N1 virus has created the need to study any probable effects of that infection in the immune system of the host. METHODOLOGY/PRINCIPAL FINDINGS: Blood was sampled within the first two days of the presentation of signs of infection from 10 healthy volunteers; from 18 cases of flu-like syndrome; and from 31 cases of infection by H1N1 confirmed by reverse RT-PCR. Absolute counts of subtypes of monocytes and of lymphocytes were determined after staining with monoclonal antibodies and analysis by flow cytometry. Peripheral blood mononuclear cells (PBMCs were isolated from patients and stimulated with various bacterial stimuli. Concentrations of tumour necrosis factor-alpha, interleukin (IL-1beta, IL-6, IL-18, interferon (FN-alpha and of IFN-gamma were estimated in supernatants by an enzyme immunoassay. Infection by H1N1 was accompanied by an increase of monocytes. PBMCs of patients evoked strong cytokine production after stimulation with most of bacterial stimuli. Defective cytokine responses were shown in response to stimulation with phytohemagglutin and with heat-killed Streptococcus pneumoniae. Adaptive immune responses of H1N1-infected patients were characterized by decreases of CD4-lymphocytes and of B-lymphocytes and by increase of T-regulatory lymphocytes (Tregs. CONCLUSIONS/SIGNIFICANCE: Infection by the H1N1 virus is accompanied by a characteristic impairment of the innate immune responses characterized by defective cytokine responses to S.pneumoniae. Alterations of the adaptive immune responses are predominated by increase of Tregs. These findings signify a predisposition for pneumococcal infections after infection by H1N1 influenza.

  3. Effect of the novel influenza A (H1N1) virus in the human immune system.

    Science.gov (United States)

    Giamarellos-Bourboulis, Evangelos J; Raftogiannis, Maria; Antonopoulou, Anastasia; Baziaka, Fotini; Koutoukas, Pantelis; Savva, Athina; Kanni, Theodora; Georgitsi, Marianna; Pistiki, Aikaterini; Tsaganos, Thomas; Pelekanos, Nikolaos; Athanassia, Sofia; Galani, Labrini; Giannitsioti, Efthymia; Kavatha, Dimitra; Kontopidou, Flora; Mouktaroudi, Maria; Poulakou, Garyfallia; Sakka, Vissaria; Panagopoulos, Periklis; Papadopoulos, Antonios; Kanellakopoulou, Kyriaki; Giamarellou, Helen

    2009-12-23

    The pandemic by the novel H1N1 virus has created the need to study any probable effects of that infection in the immune system of the host. Blood was sampled within the first two days of the presentation of signs of infection from 10 healthy volunteers; from 18 cases of flu-like syndrome; and from 31 cases of infection by H1N1 confirmed by reverse RT-PCR. Absolute counts of subtypes of monocytes and of lymphocytes were determined after staining with monoclonal antibodies and analysis by flow cytometry. Peripheral blood mononuclear cells (PBMCs) were isolated from patients and stimulated with various bacterial stimuli. Concentrations of tumour necrosis factor-alpha, interleukin (IL)-1beta, IL-6, IL-18, interferon (FN)-alpha and of IFN-gamma were estimated in supernatants by an enzyme immunoassay. Infection by H1N1 was accompanied by an increase of monocytes. PBMCs of patients evoked strong cytokine production after stimulation with most of bacterial stimuli. Defective cytokine responses were shown in response to stimulation with phytohemagglutin and with heat-killed Streptococcus pneumoniae. Adaptive immune responses of H1N1-infected patients were characterized by decreases of CD4-lymphocytes and of B-lymphocytes and by increase of T-regulatory lymphocytes (Tregs). Infection by the H1N1 virus is accompanied by a characteristic impairment of the innate immune responses characterized by defective cytokine responses to S.pneumoniae. Alterations of the adaptive immune responses are predominated by increase of Tregs. These findings signify a predisposition for pneumococcal infections after infection by H1N1 influenza.

  4. Pandemic influenza A/H1N1 virus incursion into Africa: countries ...

    African Journals Online (AJOL)

    Pandemic influenza A/H1N1 virus incursion into Africa: countries, hosts and ... features are important for planning control measures between countries and to ... in humans, infections in pigs earlier reported in America, Europe and Asia were ...

  5. Inactivation of influenza A virus H1N1 by disinfection process.

    Science.gov (United States)

    Jeong, Eun Kyo; Bae, Jung Eun; Kim, In Seop

    2010-06-01

    Because any patient, health care worker, or visitor is capable of transmitting influenza to susceptible persons within hospitals, hospital-acquired influenza has been a clinical concern. Disinfection and cleaning of medical equipment, surgical instruments, and hospital environment are important measures to prevent transmission of influenza virus from hospitals to individuals. This study was conducted to evaluate the efficacy of disinfection processes, which can be easily operated at hospitals, in inactivating influenza A virus H1N1 (H1N1). The effects of 0.1 mol/L NaOH, 70% ethanol, 70% 1-propanol, solvent/detergent (S/D) using 0.3% tri (n-butyl)-phosphate and 1.0% Triton X-100, heat, and ethylene oxide (EO) treatments in inactivating H1N1 were determined. Inactivation of H1N1 was kinetically determined by the treatment of disinfectants to virus solution. Also, a surface test method, which involved drying an amount of virus on a surface and then applying the inactivation methods for 1 minute of contact time, was used to determine the virucidal activity. H1N1 was completely inactivated to undetectable levels in 1 minute of 70% ethanol, 70% 1-propanol, and solvent/detergent treatments in the surface tests as well as in the suspension tests. H1N1 was completely inactivated in 1 minute of 0.1 mol/L NaOH treatment in the suspension tests and also effectively inactivated in the surface tests with the log reduction factor of 3.7. H1N1 was inactivated to undetectable levels within 5 minutes, 2.5 minutes, and 1 minute of heat treatment at 70, 80, and 90 degrees C, respectively in the suspension tests. Also, H1N1 was completely inactivated by EO treatment in the surface tests. Common disinfectants, heat, and EO tested in this study were effective at inactivating H1N1. These results would be helpful in implementing effective disinfecting measures to prevent hospital-acquired infections. Copyright 2010 Association for Professionals in Infection Control and Epidemiology, Inc

  6. Dynamic gene expression analysis in a H1N1 influenza virus mouse pneumonia model.

    Science.gov (United States)

    Bao, Yanyan; Gao, Yingjie; Shi, Yujing; Cui, Xiaolan

    2017-06-01

    H1N1, a major pathogenic subtype of influenza A virus, causes a respiratory infection in humans and livestock that can range from a mild infection to more severe pneumonia associated with acute respiratory distress syndrome. Understanding the dynamic changes in the genome and the related functional changes induced by H1N1 influenza virus infection is essential to elucidating the pathogenesis of this virus and thereby determining strategies to prevent future outbreaks. In this study, we filtered the significantly expressed genes in mouse pneumonia using mRNA microarray analysis. Using STC analysis, seven significant gene clusters were revealed, and using STC-GO analysis, we explored the significant functions of these seven gene clusters. The results revealed GOs related to H1N1 virus-induced inflammatory and immune functions, including innate immune response, inflammatory response, specific immune response, and cellular response to interferon-beta. Furthermore, the dynamic regulation relationships of the key genes in mouse pneumonia were revealed by dynamic gene network analysis, and the most important genes were filtered, including Dhx58, Cxcl10, Cxcl11, Zbp1, Ifit1, Ifih1, Trim25, Mx2, Oas2, Cd274, Irgm1, and Irf7. These results suggested that during mouse pneumonia, changes in the expression of gene clusters and the complex interactions among genes lead to significant changes in function. Dynamic gene expression analysis revealed key genes that performed important functions. These results are a prelude to advancements in mouse H1N1 influenza virus infection biology, as well as the use of mice as a model organism for human H1N1 influenza virus infection studies.

  7. Comparison of temporal and spatial dynamics of seasonal H3N2, pandemic H1N1 and highly pathogenic avian influenza H5N1 virus infections in ferrets.

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    Judith M A van den Brand

    Full Text Available Humans may be infected by different influenza A viruses--seasonal, pandemic, and zoonotic--which differ in presentation from mild upper respiratory tract disease to severe and sometimes fatal pneumonia with extra-respiratory spread. Differences in spatial and temporal dynamics of these infections are poorly understood. Therefore, we inoculated ferrets with seasonal H3N2, pandemic H1N1 (pH1N1, and highly pathogenic avian H5N1 influenza virus and performed detailed virological and pathological analyses at time points from 0.5 to 14 days post inoculation (dpi, as well as describing clinical signs and hematological parameters. H3N2 infection was restricted to the nose and peaked at 1 dpi. pH1N1 infection also peaked at 1 dpi, but occurred at similar levels throughout the respiratory tract. H5N1 infection occurred predominantly in the alveoli, where it peaked for a longer period, from 1 to 3 dpi. The associated lesions followed the same spatial distribution as virus infection, but their severity peaked between 1 and 6 days later. Neutrophil and monocyte counts in peripheral blood correlated with inflammatory cell influx in the alveoli. Of the different parameters used to measure lower respiratory tract disease, relative lung weight and affected lung tissue allowed the best quantitative distinction between the virus groups. There was extra-respiratory spread to more tissues--including the central nervous system--for H5N1 infection than for pH1N1 infection, and to none for H3N2 infection. This study shows that seasonal, pandemic, and zoonotic influenza viruses differ strongly in the spatial and temporal dynamics of infection in the respiratory tract and extra-respiratory tissues of ferrets.

  8. Household transmission of 2009 H1N1 influenza virus in Yazd, Iran

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    F. Behnaz

    2012-08-01

    Full Text Available Summary: Objectives: The 2009 pandemic influenza A (H1N1 virus is a public health challenge. Notably, laboratory-confirmed cases do not represent the age group most susceptible to infection. To characterize the age distribution of all cases of H1N1 influenza, we studied the personal contacts of confirmed cases to identify the age group at the highest risk. Methods: We investigated the family members of 162 laboratory-confirmed cases of 2009 H1N1 in Yazd, Iran. Family members were retrospectively asked whether they had ≥2 respiratory symptoms within 7 days of the last contact with the associated index cases. The ages and symptoms of the patients as well as the interval between diagnosis and the onset of symptoms among household contacts were determined using a questionnaire. Results: We identified 596 family members of index cases, 83 (13.9% of whom developed acute respiratory illness. No acute respiratory illness was found in 104 families (64%; however, there were 2 cases in 15 families (9.3% and ≥3 cases in 4 families (24%. Household contacts from 5 to 18 years old were more susceptible to acute respiratory illness than those who were ≥51 years old (RR = 3.174, 95% CI 1.313–7.675 P-value = 0.01. Conclusion: Individuals ≤18 years old were most susceptible to infection by the H1N1 virus. Therefore, in low-income populations, prevention of the spread of H1N1 to this age group should be emphasized. Keywords: Household transmission, 2009 Influenza A (H1N1 virus

  9. Anti-pandemic influenza A (H1N1) virus potential of catechin and gallic acid.

    Science.gov (United States)

    You, Huey-Ling; Huang, Chao-Chun; Chen, Chung-Jen; Chang, Cheng-Chin; Liao, Pei-Lin; Huang, Sheng-Teng

    2018-05-01

    The pandemic influenza A (H1N1) virus has spread worldwide and infected a large proportion of the human population. Discovery of new and effective drugs for the treatment of influenza is a crucial issue for the global medical community. According to our previous study, TSL-1, a fraction of the aqueous extract from the tender leaf of Toonasinensis, has demonstrated antiviral activities against pandemic influenza A (H1N1) through the down-regulation of adhesion molecules and chemokine to prevent viral attachment. The aim of the present study was to identify the active compounds in TSL-1 which exert anti-influenza A (H1N1) virus effects. XTT assay was used to detect the cell viability. Meanwhile, the inhibitory effect on the pandemic influenza A (H1N1) virus was analyzed by observing plaque formation, qRT-PCR, neuraminidase activity, and immunofluorescence staining of influenza A-specific glycoprotein. Both catechin and gallic acid were found to be potent inhibitors in terms of influenza virus mRNA replication and MDCK plaque formation. Additionally, both compounds inhibited neuraminidase activities and viral glycoprotein. The 50% effective inhibition concentration (EC 50 ) of catechin and gallic acid for the influenza A (H1N1) virus were 18.4 μg/mL and 2.6 μg/mL, respectively; whereas the 50% cytotoxic concentrations (CC 50 ) of catechin and gallic acid were >100 μg/mL and 22.1 μg/mL, respectively. Thus, the selectivity indexes (SI) of catechin and gallic acid were >5.6 and 22.1, respectively. The present study demonstrates that catechin might be a safe reagent for long-term use to prevent influenza A (H1N1) virus infection; whereas gallic acid might be a sensitive reagent to inhibit influenza virus infection. We conclude that these two phyto-chemicals in TSL-1 are responsible for exerting anti-pandemic influenza A (H1N1) virus effects. Copyright © 2017. Published by Elsevier Taiwan LLC.

  10. Protection against H5N1 Highly Pathogenic Avian and Pandemic (H1N1) 2009 Influenza Virus Infection in Cynomolgus Monkeys by an Inactivated H5N1 Whole Particle Vaccine

    Science.gov (United States)

    Nakayama, Misako; Shichinohe, Shintaro; Itoh, Yasushi; Ishigaki, Hirohito; Kitano, Mitsutaka; Arikata, Masahiko; Pham, Van Loi; Ishida, Hideaki; Kitagawa, Naoko; Okamatsu, Masatoshi; Sakoda, Yoshihiro; Ichikawa, Takaya; Tsuchiya, Hideaki; Nakamura, Shinichiro; Le, Quynh Mai; Ito, Mutsumi; Kawaoka, Yoshihiro; Kida, Hiroshi; Ogasawara, Kazumasa

    2013-01-01

    H5N1 highly pathogenic avian influenza virus (HPAIV) infection has been reported in poultry and humans with expanding clade designations. Therefore, a vaccine that induces immunity against a broad spectrum of H5N1 viruses is preferable for pandemic preparedness. We established a second H5N1 vaccine candidate, A/duck/Hokkaido/Vac-3/2007 (Vac-3), in our virus library and examined the efficacy of inactivated whole particles of this strain against two clades of H5N1 HPAIV strains that caused severe morbidity in cynomolgus macaques. Virus propagation in vaccinated macaques infected with either of the H5N1 HPAIV strains was prevented compared with that in unvaccinated macaques. This vaccine also prevented propagation of a pandemic (H1N1) 2009 virus in macaques. In the vaccinated macaques, neutralization activity, which was mainly shown by anti-hemagglutinin antibody, against H5N1 HPAIVs in plasma was detected, but that against H1N1 virus was not detected. However, neuraminidase inhibition activity in plasma and T-lymphocyte responses in lymph nodes against H1N1 virus were detected. Therefore, cross-clade and heterosubtypic protective immunity in macaques consisted of humoral and cellular immunity induced by vaccination with Vac-3. PMID:24376571

  11. Protection against H5N1 highly pathogenic avian and pandemic (H1N1 2009 influenza virus infection in cynomolgus monkeys by an inactivated H5N1 whole particle vaccine.

    Directory of Open Access Journals (Sweden)

    Misako Nakayama

    Full Text Available H5N1 highly pathogenic avian influenza virus (HPAIV infection has been reported in poultry and humans with expanding clade designations. Therefore, a vaccine that induces immunity against a broad spectrum of H5N1 viruses is preferable for pandemic preparedness. We established a second H5N1 vaccine candidate, A/duck/Hokkaido/Vac-3/2007 (Vac-3, in our virus library and examined the efficacy of inactivated whole particles of this strain against two clades of H5N1 HPAIV strains that caused severe morbidity in cynomolgus macaques. Virus propagation in vaccinated macaques infected with either of the H5N1 HPAIV strains was prevented compared with that in unvaccinated macaques. This vaccine also prevented propagation of a pandemic (H1N1 2009 virus in macaques. In the vaccinated macaques, neutralization activity, which was mainly shown by anti-hemagglutinin antibody, against H5N1 HPAIVs in plasma was detected, but that against H1N1 virus was not detected. However, neuraminidase inhibition activity in plasma and T-lymphocyte responses in lymph nodes against H1N1 virus were detected. Therefore, cross-clade and heterosubtypic protective immunity in macaques consisted of humoral and cellular immunity induced by vaccination with Vac-3.

  12. Infection with human H1N1 influenza virus affects the expression of sialic acids of metaplastic mucous cells in the ferret airways

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Martel, Cyril Jean-Marie; Aasted, Bent

    2009-01-01

    Glycans terminating in sialic acids serve as receptors for influenza viruses. In this study ferrets were infected with influenza virus A/New Caledonia/20/99, and the in situ localization of sialic acids linked a2-3 and a2-6 in the airways was investigated in infected and non-infected animals by use...

  13. Pandemic H1N1 2009 virus in Norwegian pigs naïve to influenza A viruses

    DEFF Research Database (Denmark)

    Germundsson, A.; Gjerset, B.; Hjulsager, Charlotte Kristiane

    In March-April 2009, a novel pandemic influenza A (H1N1) virus (pH1N1-09v) emerged in the human population. The first case of pH1N1v infection in pigs was reported from Canada in May 2009. In Norway, pH1N1v infection was recorded in a swine herd on the 10th of October of 2009. Here, we report...... isolated from a confirmed human case at the farm. The majority of the positive herds had a history of contact with humans that were diagnosed with pandemic influenza or with ILI. This suggests that infected humans are the most likely source for introduction of pH1N1-09v to the Norwegian pig herds...

  14. Signal Immune Reactions of Macrophages Differentiated from THP-1 Monocytes to Infection with Pandemic H1N1PDM09 Virus and H5N2 and H9N2 Avian Influenza A Virus.

    Science.gov (United States)

    Sokolova, T M; Poloskov, V V; Shuvalov, A N; Rudneva, I A; Timofeeva, T A

    2018-03-01

    In culture of THP-1 cells differentiated into macrophages with PMA (THP-PMA macrophages) infected with influenza viruses of subtypes H1, H5 and H9, we measured the expression of TLR7 and RIG1 receptor genes, sensors of viral RNA and ribonucleoprotein, and the levels of production of inflammatory cytokines IL-1β, TNFα, IL-10, and IFNα. The sensitivity and inflammatory response of THP-PMA macrophages to pandemic influenza A virus H1N1pdm09 and avian influenza H5N2 and H9N2 viruses correlate with the intracellular level of their viral RNA and activation of the RIG1 gene. Abortive infection is accompanied by intensive macrophage secretion of TNFα, IL-1β, and toxic factors inducing cell death. Activity of endosomal TLR7 receptor gene changed insignificantly in 24 h after infection and significantly decreased in 48 and 72 h under the action of H5N2 and H9N2, which correlated with manifestation of the cytopathogenic effect of these viruses. H5N2 and H9N2 avian viruses in THP-PMA macrophages are strong activators of the expression of the gene of the cytoplasmic RIG1 receptor 24 and 48 h after infection, and the pandemic virus H1N1pdm09 is a weak stimulator of RIG1 gene. Avian influenza H5N2 and H9N2 viruses are released by rapid induction of the inflammatory response in macrophages. At the late stages of infection, we observed a minor increase in IL-10 secretion in macrophages and, probably, the polarization of a part of the population in type M2. The studied influenza A viruses are weak inductors of IFN in THP-PMA macrophages. In the culture medium of THP-PMA macrophages infected with H9N2 and H5N2 viruses, MTT test revealed high levels of toxic factors causing the death of Caco-2 cells. In contrast to avian viruses, pandemic virus H1N1pdm09 did not induce production of toxic factors.

  15. Reassortant H1N1 influenza virus vaccines protect pigs against pandemic H1N1 influenza virus and H1N2 swine influenza virus challenge.

    Science.gov (United States)

    Yang, Huanliang; Chen, Yan; Shi, Jianzhong; Guo, Jing; Xin, Xiaoguang; Zhang, Jian; Wang, Dayan; Shu, Yuelong; Qiao, Chuanling; Chen, Hualan

    2011-09-28

    Influenza A (H1N1) virus has caused human influenza outbreaks in a worldwide pandemic since April 2009. Pigs have been found to be susceptible to this influenza virus under experimental and natural conditions, raising concern about their potential role in the pandemic spread of the virus. In this study, we generated a high-growth reassortant virus (SC/PR8) that contains the hemagglutinin (HA) and neuraminidase (NA) genes from a novel H1N1 isolate, A/Sichuan/1/2009 (SC/09), and six internal genes from A/Puerto Rico/8/34 (PR8) virus, by genetic reassortment. The immunogenicity and protective efficacy of this reassortant virus were evaluated at different doses in a challenge model using a homologous SC/09 or heterologous A/Swine/Guangdong/1/06(H1N2) virus (GD/06). Two doses of SC/PR8 virus vaccine elicited high-titer serum hemagglutination inhibiting (HI) antibodies specific for the 2009 H1N1 virus and conferred complete protection against challenge with either SC/09 or GD/06 virus, with reduced lung lesions and viral shedding in vaccine-inoculated animals compared with non-vaccinated control animals. These results indicated for the first time that a high-growth SC/PR8 reassortant H1N1 virus exhibits properties that are desirable to be a promising vaccine candidate for use in swine in the event of a pandemic H1N1 influenza. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Pandemic 2009 Influenza A (H1N1 virus infection in cancer and hematopoietic stem cell transplant recipients; a multicenter observational study. [v1; ref status: indexed, http://f1000r.es/4bi

    Directory of Open Access Journals (Sweden)

    Maria Cecilia Dignani

    2014-09-01

    Full Text Available Background: During March 2009 a novel Influenza A virus emerged in Mexico. We describe the clinical picture of the pandemic Influenza A (H1N1 Influenza in cancer patients during the 2009 influenza season. Methods: Twelve centers participated in a multicenter retrospective observational study of cancer patients with confirmed infection with the 2009 H1N1 Influenza A virus (influenza-like illness or pneumonia plus positive PCR for the 2009 H1N1 Influenza A virus  in respiratory secretions. Clinical data were obtained by retrospective chart review and analyzed.  Results: From May to August 2009, data of 65 patients were collected. Median age was 51 years, 57 % of the patients were female. Most patients (47 had onco-hematological cancers and 18 had solid tumors. Cancer treatment mainly consisted of chemotherapy (46, or stem cell transplantation (SCT (16. Only 19 of 64 patients had received the 2009 seasonal Influenza vaccine. Clinical presentation included pneumonia (43 and upper respiratory tract infection (22. Forty five of 58 ambulatory patients were admitted. Mechanical ventilation was required in 12 patients (18%. Treatment included oseltamivir monotherapy or in combination with amantadine for a median of 7 days. The global 30-day mortality rate was 18%. All 12 deaths were among the non-vaccinated patients. No deaths were observed among the 19 vaccinated patients. Oxygen saturation <96% at presentation was a predictor of mortality (OR 19.5; 95%CI: 2.28 to 165.9. Conclusions: In our cancer patient population, the pandemic 2009 Influenza A (H1N1 virus was associated with high incidence of pneumonia (66%, and 30-day mortality (18.5%. Saturation <96% was significantly associated with death. No deaths were observed among vaccinated patients.

  17. Pandemic influenza A/H1N1 virus infection and TNF, LTA, IL1B, IL6, IL8, and CCL polymorphisms in Mexican population: a case-control study.

    Science.gov (United States)

    Morales-García, Guadalupe; Falfán-Valencia, Ramcés; García-Ramírez, Román Alejandro; Camarena, Ángel; Ramirez-Venegas, Alejandra; Castillejos-López, Manuel; Pérez-Rodríguez, Martha; González-Bonilla, César; Grajales-Muñíz, Concepción; Borja-Aburto, Víctor; Mejía-Aranguré, Juan Manuel

    2012-11-13

    Some patients have a greater response to viral infection than do others having a similar level of viral replication. Hypercytokinemia is the principal immunopathological mechanism that contributes to a severer clinical course in cases of influenza A/H1N1. The benefit produced, or damage caused, by these cytokines in severe disease is not known. The genes that code for these molecules are polymorphic and certain alleles have been associated with susceptibility to various diseases. The objective of the present study was to determine whether there was an association between polymorphisms of TNF, LTA, IL1B, IL6, IL8, and CCL1 and the infection and severity of the illness caused by the pandemic A/H1N1 in Mexico in 2009. Case-control study. The cases were patients confirmed with real time PCR with infection by the A/H1N1 pandemic virus. The controls were patients with infection like to influenza and non-familial healthy contacts of the patients with influenza. Medical history and outcome of the disease was registered. The DNA samples were genotyped for polymorphisms TNF rs361525, rs1800629, and rs1800750; LTA rs909253; IL1B rs16944; IL6 rs1818879; IL8 rs4073; and CCL1 rs2282691. Odds ratio (OR) and the 95% confidence interval (95% CI) were calculated. The logistic regression model was adjusted by age and severity of the illness in cases. Infection with the pandemic A/H1N1 virus was associated with the following genotypes: TNF rs361525 AA, OR = 27.00; 95% CI = 3.07-1248.77); LTA rs909253 AG (OR = 4.33, 95% CI = 1.82-10.32); TNF rs1800750 AA (OR = 4.33, 95% CI = 1.48-12.64); additionally, LTA rs909253 AG showed a limited statistically significant association with mortality (p = 0.06, OR = 3.13). Carriers of the TNF rs1800629 GA genotype were associated with high levels of blood urea nitrogen (p = 0.05); those of the TNF rs1800750 AA genotype, with high levels of creatine phosphokinase (p=0.05). The IL1B rs16944 AA genotype was associated with an elevated number of

  18. Pandemic influenza A/H1N1 virus infection and TNF, LTA, IL1B, IL6, IL8, and CCL polymorphisms in Mexican population: a case–control study

    Science.gov (United States)

    2012-01-01

    Background Some patients have a greater response to viral infection than do others having a similar level of viral replication. Hypercytokinemia is the principal immunopathological mechanism that contributes to a severer clinical course in cases of influenza A/H1N1. The benefit produced, or damage caused, by these cytokines in severe disease is not known. The genes that code for these molecules are polymorphic and certain alleles have been associated with susceptibility to various diseases. The objective of the present study was to determine whether there was an association between polymorphisms of TNF, LTA, IL1B, IL6, IL8, and CCL1 and the infection and severity of the illness caused by the pandemic A/H1N1 in Mexico in 2009. Methods Case–control study. The cases were patients confirmed with real time PCR with infection by the A/H1N1 pandemic virus. The controls were patients with infection like to influenza and non-familial healthy contacts of the patients with influenza. Medical history and outcome of the disease was registered. The DNA samples were genotyped for polymorphisms TNF rs361525, rs1800629, and rs1800750; LTA rs909253; IL1B rs16944; IL6 rs1818879; IL8 rs4073; and CCL1 rs2282691. Odds ratio (OR) and the 95% confidence interval (95% CI) were calculated. The logistic regression model was adjusted by age and severity of the illness in cases. Results Infection with the pandemic A/H1N1 virus was associated with the following genotypes: TNF rs361525 AA, OR = 27.00; 95% CI = 3.07–1248.77); LTA rs909253 AG (OR = 4.33, 95% CI = 1.82–10.32); TNF rs1800750 AA (OR = 4.33, 95% CI = 1.48–12.64); additionally, LTA rs909253 AG showed a limited statistically significant association with mortality (p = 0.06, OR = 3.13). Carriers of the TNF rs1800629 GA genotype were associated with high levels of blood urea nitrogen (p = 0.05); those of the TNF rs1800750 AA genotype, with high levels of creatine phosphokinase (p=0.05). The IL1B rs16944 AA genotype was associated

  19. Pandemic influenza A/H1N1 virus infection and TNF, LTA, IL1B, IL6, IL8, and CCL polymorphisms in Mexican population: a case–control study

    Directory of Open Access Journals (Sweden)

    Morales-García Guadalupe

    2012-11-01

    Full Text Available Abstract Background Some patients have a greater response to viral infection than do others having a similar level of viral replication. Hypercytokinemia is the principal immunopathological mechanism that contributes to a severer clinical course in cases of influenza A/H1N1. The benefit produced, or damage caused, by these cytokines in severe disease is not known. The genes that code for these molecules are polymorphic and certain alleles have been associated with susceptibility to various diseases. The objective of the present study was to determine whether there was an association between polymorphisms of TNF, LTA, IL1B, IL6, IL8, and CCL1 and the infection and severity of the illness caused by the pandemic A/H1N1 in Mexico in 2009. Methods Case–control study. The cases were patients confirmed with real time PCR with infection by the A/H1N1 pandemic virus. The controls were patients with infection like to influenza and non-familial healthy contacts of the patients with influenza. Medical history and outcome of the disease was registered. The DNA samples were genotyped for polymorphisms TNF rs361525, rs1800629, and rs1800750; LTA rs909253; IL1B rs16944; IL6 rs1818879; IL8 rs4073; and CCL1 rs2282691. Odds ratio (OR and the 95% confidence interval (95% CI were calculated. The logistic regression model was adjusted by age and severity of the illness in cases. Results Infection with the pandemic A/H1N1 virus was associated with the following genotypes: TNF rs361525 AA, OR = 27.00; 95% CI = 3.07–1248.77; LTA rs909253 AG (OR = 4.33, 95% CI = 1.82–10.32; TNF rs1800750 AA (OR = 4.33, 95% CI = 1.48–12.64; additionally, LTA rs909253 AG showed a limited statistically significant association with mortality (p = 0.06, OR = 3.13. Carriers of the TNF rs1800629 GA genotype were associated with high levels of blood urea nitrogen (p = 0.05; those of the TNF rs1800750 AA genotype, with high levels of creatine phosphokinase (p=0.05. The IL1B rs16944 AA

  20. Viral hemagglutinin is involved in promoting the internalisation of Staphylococcus aureus into human pneumocytes during influenza A H1N1 virus infection.

    Science.gov (United States)

    Passariello, Claudio; Nencioni, Lucia; Sgarbanti, Rossella; Ranieri, Danilo; Torrisi, Maria Rosaria; Ripa, Sandro; Garaci, Enrico; Palamara, Anna Teresa

    2011-02-01

    Secondary pneumonia caused by Staphylococcus aureus is reemerging as a primary cause of excess mortality associated with infection by the influenza A virus. We have investigated in vitro the cellular and molecular mechanisms underlying this synergism. Experimental data show a significant increase in the efficiency of internalisation of S. aureus into cultured pneumocytes during the early phases of viral infection, while a relevant increase in the efficiency of adhesion is evident only later during viral infection, suggesting that the 2 effects are based on different molecular mechanisms. Data reported in this paper show that S. aureus cells can bind the viral hemagglutinin (HA) and that this binding promotes enhanced bacterial internalisation by 2 mechanisms: binding to HA exposed at the surface of infected cells and binding to free extracellular virions, enabling internalisation at high efficiency also in cells that are not infected by the virus. The affinity of binding that involves S. aureus and HA was shown to be enhanced by the reducing extracellular environment that the virus can generate. Copyright © 2010 Elsevier GmbH. All rights reserved.

  1. Modified vaccinia virus Ankara expressing the hemagglutinin of pandemic (H1N1) 2009 virus induces cross-protective immunity against Eurasian 'avian-like' H1N1 swine viruses in mice.

    Science.gov (United States)

    Castrucci, Maria R; Facchini, Marzia; Di Mario, Giuseppina; Garulli, Bruno; Sciaraffia, Ester; Meola, Monica; Fabiani, Concetta; De Marco, Maria A; Cordioli, Paolo; Siccardi, Antonio; Kawaoka, Yoshihiro; Donatelli, Isabella

    2014-05-01

    To examine cross-reactivity between hemagglutinin (HA) derived from A/California/7/09 (CA/09) virus and that derived from representative Eurasian "avian-like" (EA) H1N1 swine viruses isolated in Italy between 1999 and 2008 during virological surveillance in pigs. Modified vaccinia virus Ankara (MVA) expressing the HA gene of CA/09 virus (MVA-HA-CA/09) was used as a vaccine to investigate cross-protective immunity against H1N1 swine viruses in mice. Two classical swine H1N1 (CS) viruses and four representative EA-like H1N1 swine viruses previously isolated during outbreaks of respiratory disease in pigs on farms in Northern Italy were used in this study. Female C57BL/6 mice were vaccinated with MVA/HA/CA/09 and then challenged intranasally with H1N1 swine viruses. Cross-reactive antibody responses were determined by hemagglutination- inhibition (HI) and virus microneutralizing (MN) assays of sera from MVA-vaccinated mice. The extent of protective immunity against infection with H1N1 swine viruses was determined by measuring lung viral load on days 2 and 4 post-challenge. Systemic immunization of mice with CA/09-derived HA, vectored by MVA, elicited cross-protective immunity against recent EA-like swine viruses. This immune protection was related to the levels of cross-reactive HI antibodies in the sera of the immunized mice and was dependent on the similarity of the antigenic site Sa of H1 HAs. Our findings suggest that the herd immunity elicited in humans by the pandemic (H1N1) 2009 virus could limit the transmission of recent EA-like swine HA genes into the influenza A virus gene pool in humans. © 2013 The Authors Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  2. Frequency of respiratory virus infections and next-generation analysis of influenza A/H1N1pdm09 dynamics in the lower respiratory tract of patients admitted to the ICU.

    Directory of Open Access Journals (Sweden)

    Antonio Piralla

    Full Text Available Recent molecular diagnostic methods have significantly improved the diagnosis of viral pneumonia in intensive care units (ICUs. It has been observed that 222G/N changes in the HA gene of H1N1pdm09 are associated with increased lower respiratory tract (LRT replication and worse clinical outcome. In the present study, the frequency of respiratory viruses was assessed in respiratory samples from 88 patients admitted to 16 ICUs during the 2014-2015 winter-spring season in Lombardy. Sixty-nine out of 88 (78.4% patients were positive for a respiratory viral infection at admission. Of these, 57/69 (82.6% were positive for influenza A (41 A/H1N1pdm09 and 15 A/H3N2, 8/69 (11.6% for HRV, 2/69 (2.9% for RSV and 2/69 (2.9% for influenza B. Phylogenetic analysis of influenza A/H1N1pdm09 strains from 28/41 ICU-patients and 21 patients with mild respiratory syndrome not requiring hospitalization, showed the clear predominance of subgroup 6B strains. The median influenza A load in LRT samples of ICU patients was higher than that observed in the upper respiratory tract (URT (p<0.05. Overall, a greater number of H1N1pdm09 virus variants were observed using next generation sequencing on partial HA sequences (codons 180-286 in clinical samples from the LRT as compared to URT. In addition, 222G/N/A mutations were observed in 30% of LRT samples from ICU patients. Finally, intra-host evolution analysis showed the presence of different dynamics of viral population in LRT of patients hospitalized in ICU with a severe influenza infection.

  3. Oseltamivir Pharmacokinetics and Clinical Experience in Neonates and Infants during an Outbreak of H1N1 Influenza A Virus Infection in a Neonatal Intensive Care Unit

    Science.gov (United States)

    Nika, Angela; Tsagris, Vasileios; Kapetanakis, Ioannis; Maltezou, Helena C.; Kafetzis, Dimitris A.; Tsolia, Maria N.

    2012-01-01

    Detailed oseltamivir pharmacokinetics have yet to be reported in neonates and infants; this group is at high risk of serious influenza-associated complications. Extrapolation of doses from older patients is complicated by rapid organ and drug-metabolizing enzyme maturation. A pharmacokinetic study has been conducted during an influenza A(H1N1) outbreak in a neonatal intensive care unit. Each included patient provided 4 samples for oseltamivir and 4 samples for its active metabolite oseltamivir carboxylate. A population pharmacokinetic model was developed with NONMEM. Allometric weight scaling and maturation functions were added a priori to scale for size and age based on literature values. Nine neonates and infants were recruited. A physiologically parameterized pharmacokinetic model predicted typical day 1 area under the curve (AUC0-12) values of 1,966 and 2,484 μg · h/liter for neonates and infants of ≤37 weeks of postmenstrual age (PMA) and >37 weeks of PMA treated with 1 mg/kg of body weight and 2 mg/kg, respectively. The corresponding steady-state AUC0-12 values were 3,670 and 4,559 μg · h/liter. Premature neonates treated with 1 mg/kg and term babies treated with 2 mg/kg should have average oseltamivir carboxylate concentrations in a range similar to that for adults treated with 75 mg, corresponding to >200-fold above the half-maximal inhibitory concentration (IC50) value for influenza A(H1N1) from the start of therapy. PMID:22564835

  4. Pandemic H1N1 2009 virus in Danish pigs: Diagnosis and lack of surveillance

    DEFF Research Database (Denmark)

    Larsen, Lars Erik; Nielsen, L. P.; Breum, Solvej Østergaard

    In March-April 2009, a novel pandemic H1N1 virus (H1N1v) of likely swine origin emerged in the human population globally. The first case in pigs was reported from Canada in May 2009 and presently almost all countries with pig production have reported cases. The emergence of a new influenza subtype...

  5. Case-based reported mortality associated with laboratory-confirmed influenza A(H1N1 2009 virus infection in the Netherlands: the 2009-2010 pandemic season versus the 2010-2011 influenza season

    Directory of Open Access Journals (Sweden)

    Timen Aura

    2011-10-01

    Full Text Available Abstract Background In contrast to seasonal influenza epidemics, where the majority of deaths occur amongst elderly, a considerable part of the 2009 pandemic influenza related deaths concerned relatively young people. In the Netherlands, all deaths associated with laboratory-confirmed influenza A(H1N1 2009 virus infection had to be notified, both during the 2009-2010 pandemic season and the 2010-2011 influenza season. To assess whether and to what extent pandemic mortality patterns were reverting back to seasonal patterns, a retrospective analyses of all notified fatal cases associated with laboratory-confirmed influenza A(H1N1 2009 virus infection was performed. Methods The notification database, including detailed information about the clinical characteristics of all notified deaths, was used to perform a comprehensive analysis of all deceased patients with a laboratory-confirmed influenza A(H1N1 2009 virus infection. Characteristics of the fatalities with respect to age and underlying medical conditions were analysed, comparing the 2009-2010 pandemic and the 2010-2011 influenza season. Results A total of 65 fatalities with a laboratory-confirmed influenza A(H1N1 2009 virus infection were notified in 2009-2010 and 38 in 2010-2011. During the pandemic season, the population mortality rates peaked in persons aged 0-15 and 55-64 years. In the 2010-2011 influenza season, peaks in mortality were seen in persons aged 0-15 and 75-84 years. During the 2010-2011 influenza season, the height of first peak was lower compared to that during the pandemic season. Underlying immunological disorders were more common in the pandemic season compared to the 2010-2011 season (p = 0.02, and cardiovascular disorders were more common in the 2010-2011 season (p = 0.005. Conclusions The mortality pattern in the 2010-2011 influenza season still resembled the 2009-2010 pandemic season with a peak in relatively young age groups, but concurrently a clear shift toward

  6. Computed tomography findings in patients with H1N1 influenza A infection

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, Viviane Brandao; Rodrigues, Rosana Souza; Barreto, Miriam Menna; Marchiori, Edson, E-mail: edmarchiori@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Zanetti, Glaucia [Faculdade de Medicina de Petropolis (FMP), RJ (Brazil)

    2013-09-15

    The present study aimed to review high resolution computed tomography findings in patients with H1N1 influenza A infection. The most common tomographic findings include ground-glass opacities, areas of consolidation or a combination of both patterns. Some patients may also present bronchial wall thickening, airspace nodules, crazy-paving pattern, perilobular opacity, air trapping and findings related to organizing pneumonia. These abnormalities are frequently bilateral, with subpleural distribution. Despite their non specificity, it is important to recognize the main tomographic findings in patients affected by H1N1 virus in order to include this possibility in the differential diagnosis, characterize complications and contribute in the follow-up, particularly in cases of severe disease. (author)

  7. Computed tomography findings in patients with H1N1 influenza A infection

    International Nuclear Information System (INIS)

    Amorim, Viviane Brandao; Rodrigues, Rosana Souza; Barreto, Miriam Menna; Marchiori, Edson; Zanetti, Glaucia

    2013-01-01

    The present study aimed to review high resolution computed tomography findings in patients with H1N1 influenza A infection. The most common tomographic findings include ground-glass opacities, areas of consolidation or a combination of both patterns. Some patients may also present bronchial wall thickening, airspace nodules, crazy-paving pattern, perilobular opacity, air trapping and findings related to organizing pneumonia. These abnormalities are frequently bilateral, with subpleural distribution. Despite their non specificity, it is important to recognize the main tomographic findings in patients affected by H1N1 virus in order to include this possibility in the differential diagnosis, characterize complications and contribute in the follow-up, particularly in cases of severe disease. (author)

  8. Assessing Google flu trends performance in the United States during the 2009 influenza virus A (H1N1 pandemic.

    Directory of Open Access Journals (Sweden)

    Samantha Cook

    Full Text Available BACKGROUND: Google Flu Trends (GFT uses anonymized, aggregated internet search activity to provide near-real time estimates of influenza activity. GFT estimates have shown a strong correlation with official influenza surveillance data. The 2009 influenza virus A (H1N1 pandemic [pH1N1] provided the first opportunity to evaluate GFT during a non-seasonal influenza outbreak. In September 2009, an updated United States GFT model was developed using data from the beginning of pH1N1. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated the accuracy of each U.S. GFT model by comparing weekly estimates of ILI (influenza-like illness activity with the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet. For each GFT model we calculated the correlation and RMSE (root mean square error between model estimates and ILINet for four time periods: pre-H1N1, Summer H1N1, Winter H1N1, and H1N1 overall (Mar 2009-Dec 2009. We also compared the number of queries, query volume, and types of queries (e.g., influenza symptoms, influenza complications in each model. Both models' estimates were highly correlated with ILINet pre-H1N1 and over the entire surveillance period, although the original model underestimated the magnitude of ILI activity during pH1N1. The updated model was more correlated with ILINet than the original model during Summer H1N1 (r = 0.95 and 0.29, respectively. The updated model included more search query terms than the original model, with more queries directly related to influenza infection, whereas the original model contained more queries related to influenza complications. CONCLUSIONS: Internet search behavior changed during pH1N1, particularly in the categories "influenza complications" and "term for influenza." The complications associated with pH1N1, the fact that pH1N1 began in the summer rather than winter, and changes in health-seeking behavior each may have played a part. Both GFT models performed well prior to and during pH1

  9. Assessing Google Flu Trends Performance in the United States during the 2009 Influenza Virus A (H1N1) Pandemic

    Science.gov (United States)

    Cook, Samantha; Conrad, Corrie; Fowlkes, Ashley L.; Mohebbi, Matthew H.

    2011-01-01

    Background Google Flu Trends (GFT) uses anonymized, aggregated internet search activity to provide near-real time estimates of influenza activity. GFT estimates have shown a strong correlation with official influenza surveillance data. The 2009 influenza virus A (H1N1) pandemic [pH1N1] provided the first opportunity to evaluate GFT during a non-seasonal influenza outbreak. In September 2009, an updated United States GFT model was developed using data from the beginning of pH1N1. Methodology/Principal Findings We evaluated the accuracy of each U.S. GFT model by comparing weekly estimates of ILI (influenza-like illness) activity with the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet). For each GFT model we calculated the correlation and RMSE (root mean square error) between model estimates and ILINet for four time periods: pre-H1N1, Summer H1N1, Winter H1N1, and H1N1 overall (Mar 2009–Dec 2009). We also compared the number of queries, query volume, and types of queries (e.g., influenza symptoms, influenza complications) in each model. Both models' estimates were highly correlated with ILINet pre-H1N1 and over the entire surveillance period, although the original model underestimated the magnitude of ILI activity during pH1N1. The updated model was more correlated with ILINet than the original model during Summer H1N1 (r = 0.95 and 0.29, respectively). The updated model included more search query terms than the original model, with more queries directly related to influenza infection, whereas the original model contained more queries related to influenza complications. Conclusions Internet search behavior changed during pH1N1, particularly in the categories “influenza complications” and “term for influenza.” The complications associated with pH1N1, the fact that pH1N1 began in the summer rather than winter, and changes in health-seeking behavior each may have played a part. Both GFT models performed well prior to and during pH1N1

  10. Heterogeneous virulence of pandemic 2009 influenza H1N1 virus in mice

    Directory of Open Access Journals (Sweden)

    Farooqui Amber

    2012-06-01

    Full Text Available Abstract Background Understanding the pathogenesis of influenza infection is a key factor leading to the prevention and control of future outbreaks. Pandemic 2009 Influenza H1N1 infection, although frequently mild, led to a severe and fatal form of disease in certain cases that make its virulence nature debatable. Much effort has been made toward explaining the determinants of disease severity; however, no absolute reason has been established. Results This study presents the heterogeneous virulence of clinically similar strains of pandemic 2009 influenza virus in human alveolar adenocarcinoma cells and mice. The viruses were obtained from patients who were admitted in a local hospital in China with a similar course of infection and recovered. The A/Nanchang/8002/2009 and A/Nanchang/8011/2009 viruses showed efficient replication and high lethality in mice while infection with A/Nanchang/8008/2009 was not lethal with impaired viral replication, minimal pathology and modest proinflammatory activity in lungs. Sequence analysis displayed prominent differences between polymerase subunits (PB2 and PA of viral genomes that might correlate with their different phenotypic behavior. Conclusions The study confirms that biological heterogeneity, linked with the extent of viral replication, exists among pandemic H1N1 strains that may serve as a benchmark for future investigations on influenza pathogenesis.

  11. Outcomes of Oseltamivir Treatment for H1N1 Infection During Pregnancy: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    Nermin Akdemir

    2011-04-01

    CONCLUSION: In this retrospective, study, we found that, H1N1 infection during pregnancy has a good prognosis and without complication for maternal health. Although oseltamivir therapy is safe in pregnant women, it can be associated with cardiac structural cardiac malformations in H1N1 infected pregnancy newborns

  12. Replication, Pathogenesis and Transmission of Pandemic (H1N1) 2009 Virus in Non-Immune Pigs

    DEFF Research Database (Denmark)

    Brookes, Sharon M; Nunez, Alejandor; Choudhury, Bhudipa

    2010-01-01

    The declaration of the human influenza A pandemic (H1N1) 2009 (H1N1/09) raised important questions, including origin and host range [1,2]. Two of the three pandemics in the last century resulted in the spread of virus to pigs (H1N1, 1918; H3N2, 1968) with subsequent independent establishment...... and evolution within swine worldwide [3]. A key public and veterinary health consideration in the context of the evolving pandemic is whether the H1N1/09 virus could become established in pig populations [4]. We performed an infection and transmission study in pigs with A/California/07/09. In combination......, with clearly demonstrable pulmonary pathology, there was apparent selection of a virus variant with glycine (225G). These findings provide potential clues to the existence and biological significance of viral receptor-binding variants with 225D and 225G during the 1918 pandemic [5]....

  13. Evolution and adaptation of the pandemic A/H1N1 2009 influenza virus

    Directory of Open Access Journals (Sweden)

    Ducatez MF

    2011-07-01

    Full Text Available Mariette F Ducatez, Thomas P Fabrizio, Richard J WebbyDepartment of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USAAbstract: The emergence of the 2009 H1N1 pandemic influenza virus [A(H1N1pdm09] has provided the public health community with many challenges, but also the scientific community with an opportunity to monitor closely its evolution through the processes of drift and shift. To date, and despite having circulated in humans for nearly two years, little antigenic variation has been observed in the A(H1N1pdm09 viruses. However, as the A(H1N1pdm09 virus continues to circulate and the immunologic pressure within the human population increases, future antigenic change is almost a certainty. Several coinfections of A(H1N1pdm09 and seasonal A(H1N1 or A(H3N2 viruses have been observed, but no reassortant viruses have been described in humans, suggesting a lack of fitness of reassortant viruses or a lack of opportunities for interaction of different viral lineages. In contrast, multiple reassortment events have been detected in swine populations between A(H1N1 pdm09 and other endemic swine viruses. Somewhat surprisingly, many of the well characterized influenza virus virulence markers appear to have limited impact on the phenotype of the A(H1N1pdm09 viruses when they have been introduced into mutant viruses in laboratory settings. As such, it is unclear what the evolutionary path of the pandemic virus will be, but the monitoring of any changes in the circulating viruses will remain a global public and animal health priority.Keywords: influenza, pandemic, evolution, adaptation

  14. Usefulness of Ct value in acute respiratory infections caused by respiratory syncytial virus A and B and influenza virus A (H1N1)pdm09, A (H3N2) and B.

    Science.gov (United States)

    Reina, Jordi; Morales, Carmen; Busquets, María; Norte, Cristina

    2017-06-07

    Acute respiratory infections of viral cause are very frequent entities. The difficulty in evaluating the detection of a virus in these entities could be solved by determining the viral load. A prospective study on the mean Ct value (cycle threshold value) detected against RSV-A, RSV-B and influenza A (H1N1)pdm09, A (H3N2) and B viruses in patients of different origin and age was performed. Detection was performed using a commercial molecular amplification (RT-PCR) technique. Different mean Ct values were detected for each virus. In RSV infections, no differences were observed between those caused by RSV-A or RSV-B in children. Depending on the patient's age, the only statistical significance was observed in those included in the 0-4 month groups for RSV-A and this group and the 5-12 months group for RSV-B (higher values). A lower viral load was detected in adult patients than in paediatric patients. In influenza infections, no statistical significance was observed in the mean values detected in patients from the Red Centinela («sentinel network», a Spanish network of doctors aimed at research and surveillance of diseases), those diagnosed in the adult emergency room or in hospital admissions. In the adult patients admitted to the ICU, only a slightly lower mean value was observed in those infected with influenza A (H1N1)pdm09, but without statistical significance. There were no patients admitted to the ICU with influenza B infection. The detection of viral load could be a good tool for the evaluation, monitoring and prognosis of acute viral respiratory infections. With the exception of those caused by RSV, no significant differences were observed in influenza infections except in younger paediatric patients. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  15. Identification of reassortant pandemic H1N1 influenza virus in Korean pigs.

    Science.gov (United States)

    Han, Jae Yeon; Park, Sung Jun; Kim, Hye Kwon; Rho, Semi; Nguyen, Giap Van; Song, Daesub; Kang, Bo Kyu; Moon, Hyung Jun; Yeom, Min Joo; Park, Bong Kyun

    2012-05-01

    Since the 2009 pandemic human H1N1 influenza A virus emerged in April 2009, novel reassortant strains have been identified throughout the world. This paper describes the detection and isolation of reassortant strains associated with human pandemic influenza H1N1 and swine influenza H1N2 (SIV) viruses in swine populations in South Korea. Two influenza H1N2 reassortants were detected, and subtyped by PCR. The strains were isolated using Madin- Darby canine kidney (MDCK) cells, and genetically characterized by phylogenetic analysis for genetic diversity. They consisted of human, avian, and swine virus genes that were originated from the 2009 pandemic H1N1 virus and a neuraminidase (NA) gene from H1N2 SIV previously isolated in North America. This identification of reassortment events in swine farms raises concern that reassortant strains may continuously circulate within swine populations, calling for the further study and surveillance of pandemic H1N1 among swine.

  16. Corticosteroid treatment ameliorates acute lung injury induced by 2009 swine origin influenza A (H1N1 virus in mice.

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    Chenggang Li

    Full Text Available BACKGROUND: The 2009 influenza pandemic affected people in almost all countries in the world, especially in younger age groups. During this time, the debate over whether to use corticosteroid treatment in severe influenza H1N1 infections patients resurfaced and was disputed by clinicians. There is an urgent need for a susceptible animal model of 2009 H1N1 infection that can be used to evaluate the pathogenesis and the therapeutic effect of corticosteroid treatment during infection. METHODOLOGY/PRINCIPAL FINDINGS: We intranasally inoculated two groups of C57BL/6 and BALB/c mice (using 4- or 6-to 8-week-old mice to compare the pathogenesis of several different H1N1 strains in mice of different ages. Based on the results, a very susceptible 4-week-old C57BL/6 mouse model of Beijing 501 strain of 2009 H1N1 virus infection was established, showing significantly elevated lung edema and cytokine levels compared to controls. Using our established animal model, the cytokine production profile and lung histology were assessed at different times post-infection, revealing increased lung lesions in a time-dependent manner. In additional,the mice were also treated with dexamethasone, which significantly improved survival rate and lung lesions in infected mice compared to those in control mice. Our data showed that corticosteroid treatment ameliorated acute lung injury induced by the 2009 A/H1N1 virus in mice and suggested that corticosteroids are valid drugs for treating 2009 A/H1N1 infection. CONCLUSIONS/SIGNIFICANCE: Using the established, very susceptible 2009 Pandemic Influenza A (H1N1 mouse model, our studies indicate that corticosteroids are a potential therapeutic remedy that may address the increasing concerns over future 2009 A/H1N1 pandemics.

  17. Pandemic influenza 1918 H1N1 and 1968 H3N2 DNA vaccines induce cross-reactive immunity in ferrets against infection with viruses drifted for decades

    DEFF Research Database (Denmark)

    Bragstad, Karoline; Martel, Cyril; Thomsen, Joakim S.

    2011-01-01

    Please cite this paper as: Bragstad et al. (2010) Pandemic influenza 1918 H1N1 and 1968 H3N2 DNA vaccines induce cross-reactive immunity in ferrets against infection with viruses drifted for decades. Influenza and Other Respiratory Viruses 5(1), 13-23. Background Alternative influenza vaccines...... and vaccine production forms are needed as the conventional protein vaccines do not induce broad cross-reactivity against drifted strains. Furthermore, fast vaccine production is especially important in a pandemic situation, and broader vaccine reactivity would diminish the need for frequent change...... in the vaccine formulations. Objective In this study, we compared the ability of pandemic influenza DNA vaccines to induce immunity against distantly related strains within a subtype with the immunity induced by conventional trivalent protein vaccines against homologous virus challenge. Methods Ferrets were...

  18. Adaptation of Pandemic H1N1 Influenza Viruses in Mice▿

    Science.gov (United States)

    Ilyushina, Natalia A.; Khalenkov, Alexey M.; Seiler, Jon P.; Forrest, Heather L.; Bovin, Nicolai V.; Marjuki, Henju; Barman, Subrata; Webster, Robert G.; Webby, Richard J.

    2010-01-01

    The molecular mechanism by which pandemic 2009 influenza A viruses were able to sufficiently adapt to humans is largely unknown. Subsequent human infections with novel H1N1 influenza viruses prompted an investigation of the molecular determinants of the host range and pathogenicity of pandemic influenza viruses in mammals. To address this problem, we assessed the genetic basis for increased virulence of A/CA/04/09 (H1N1) and A/TN/1-560/09 (H1N1) isolates, which are not lethal for mice, in a new mammalian host by promoting their mouse adaptation. The resulting mouse lung-adapted variants showed significantly enhanced growth characteristics in eggs, extended extrapulmonary tissue tropism, and pathogenicity in mice. All mouse-adapted viruses except A/TN/1-560/09-MA2 grew faster and to higher titers in cells than the original strains. We found that 10 amino acid changes in the ribonucleoprotein (RNP) complex (PB2 E158G/A, PA L295P, NP D101G, and NP H289Y) and hemagglutinin (HA) glycoprotein (K119N, G155E, S183P, R221K, and D222G) controlled enhanced mouse virulence of pandemic isolates. HA mutations acquired during adaptation affected viral receptor specificity by enhancing binding to α2,3 together with decreasing binding to α2,6 sialyl receptors. PB2 E158G/A and PA L295P amino acid substitutions were responsible for the significant enhancement of transcription and replication activity of the mouse-adapted H1N1 variants. Taken together, our findings suggest that changes optimizing receptor specificity and interaction of viral polymerase components with host cellular factors are the major mechanisms that contribute to the optimal competitive advantage of pandemic influenza viruses in mice. These modulators of virulence, therefore, may have been the driving components of early evolution, which paved the way for novel 2009 viruses in mammals. PMID:20592084

  19. Evolutionary trends of A(H1N1 influenza virus hemagglutinin since 1918.

    Directory of Open Access Journals (Sweden)

    Jun Shen

    2009-11-01

    Full Text Available The Pandemic (H1N1 2009 is spreading to numerous countries and causing many human deaths. Although the symptoms in humans are mild at present, fears are that further mutations in the virus could lead to a potentially more dangerous outbreak in subsequent months. As the primary immunity-eliciting antigen, hemagglutinin (HA is the major agent for host-driven antigenic drift in A(H3N2 virus. However, whether and how the evolution of HA is influenced by existing immunity is poorly understood for A(H1N1. Here, by analyzing hundreds of A(H1N1 HA sequences since 1918, we show the first evidence that host selections are indeed present in A(H1N1 HAs. Among a subgroup of human A(H1N1 HAs between 1918 approximately 2008, we found strong diversifying (positive selection at HA(1 156 and 190. We also analyzed the evolutionary trends at HA(1 190 and 225 that are critical determinants for receptor-binding specificity of A(H1N1 HA. Different A(H1N1 viruses appeared to favor one of these two sites in host-driven antigenic drift: epidemic A(H1N1 HAs favor HA(1 190 while the 1918 pandemic and swine HAs favor HA(1 225. Thus, our results highlight the urgency to understand the interplay between antigenic drift and receptor binding in HA evolution, and provide molecular signatures for monitoring future antigenically drifted 2009 pandemic and seasonal A(H1N1 influenza viruses.

  20. Genetic diversity of the 2009 pandemic influenza A(H1N1 viruses in Finland.

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    Niina Ikonen

    Full Text Available BACKGROUND: In Finland, the first infections caused by the 2009 pandemic influenza A(H1N1 virus were identified on May 10. During the next three months almost all infections were found from patients who had recently traveled abroad. In September 2009 the pandemic virus started to spread in the general population, leading to localized outbreaks and peak epidemic activity was reached during weeks 43-48. METHODS/RESULTS: The nucleotide sequences of the hemagglutinin (HA and neuraminidase (NA genes from viruses collected from 138 patients were determined. The analyzed viruses represented mild and severe infections and different geographic regions and time periods. Based on HA and NA gene sequences, the Finnish pandemic viruses clustered in four groups. Finnish epidemic viruses and A/California/07/2009 vaccine virus strain varied from 2-8 and 0-5 amino acids in HA and NA molecules, respectively, giving a respective maximal evolution speed of 1.4% and 1.1%. Most amino acid changes in HA and NA molecules accumulated on the surface of the molecule and were partly located in antigenic sites. Three severe infections were detected with a mutation at HA residue 222, in two viruses with a change D222G, and in one virus D222Y. Also viruses with change D222E were identified. All Finnish pandemic viruses were sensitive to oseltamivir having the amino acid histidine at residue 275 of the neuraminidase molecule. CONCLUSIONS: The Finnish pandemic viruses were quite closely related to A/California/07/2009 vaccine virus. Neither in the HA nor in the NA were changes identified that may lead to the selection of a virus with increased epidemic potential or exceptionally high virulence. Continued laboratory-based surveillance of the 2009 pandemic influenza A(H1N1 is important in order to rapidly identify drug resistant viruses and/or virus variants with potential ability to cause severe forms of infection and an ability to circumvent vaccine-induced immunity.

  1. Recurrent Spontaneous Pneumothorax during the Recovery Phase of ARDS Due to H1N1 Infection

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    Canan Bor

    2013-03-01

    Full Text Available The pregnant patients are prone to influenza A (H1N1 virus infection, which may rapidly progress to lower respiratory tract infection and subsequent respiratory failure and acute respiratory distress syndrome (ARDS. Pneumothorax might develop in ARDS under mechanical ventilation. But post-ARDS pneumothorax in spontaneously breathing patient has not been reported in the literature. We report a 31-year old pregnant woman infected with influenza A (H1N1 virus and progressed to ARDS. Mechanical ventilation with high PEEP improved patient's gas exchange parameters within 3 weeks. However spontaneous pneumothorax was developed one week after she weaned off the ventilator. After successful drainage therapy, the patient was discharged. However she re-admitted to the hospital because of a recurrent pneumothorax one week later. She was discharged in good health after being treated with negative continuous pleural aspiration for 10 days. Influenza might cause severe pulmonary infection and death. In addition to diffuse alveolar damage, sub-pleural and intrapulmonary air cysts might occur in influenza-related ARDS and may lead to spontaneous pneumothorax. This complication should always be considered during the recovery period of ARDS and a long-term close follow-up is necessary.

  2. Caveolin-1 influences human influenza A virus (H1N1 multiplication in cell culture

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    Hemgård Gun-Viol

    2010-05-01

    Full Text Available Abstract Background The threat of recurring influenza pandemics caused by new viral strains and the occurrence of escape mutants necessitate the search for potent therapeutic targets. The dependence of viruses on cellular factors provides a weak-spot in the viral multiplication strategy and a means to interfere with viral multiplication. Results Using a motif-based search strategy for antiviral targets we identified caveolin-1 (Cav-1 as a putative cellular interaction partner of human influenza A viruses, including the pandemic influenza A virus (H1N1 strains of swine origin circulating from spring 2009 on. The influence of Cav-1 on human influenza A/PR/8/34 (H1N1 virus replication was determined in inhibition and competition experiments. RNAi-mediated Cav-1 knock-down as well as transfection of a dominant-negative Cav-1 mutant results in a decrease in virus titre in infected Madin-Darby canine kidney cells (MDCK, a cell line commonly used in basic influenza research as well as in virus vaccine production. To understand the molecular basis of the phenomenon we focussed on the putative caveolin-1 binding domain (CBD located in the lumenal, juxtamembranal portion of the M2 matrix protein which has been identified in the motif-based search. Pull-down assays and co-immunoprecipitation experiments showed that caveolin-1 binds to M2. The data suggest, that Cav-1 modulates influenza virus A replication presumably based on M2/Cav-1 interaction. Conclusion As Cav-1 is involved in the human influenza A virus life cycle, the multifunctional protein and its interaction with M2 protein of human influenza A viruses represent a promising starting point for the search for antiviral agents.

  3. Antigenically Diverse Swine Origin H1N1 Variant Influenza Viruses Exhibit Differential Ferret Pathogenesis and Transmission Phenotypes.

    Science.gov (United States)

    Pulit-Penaloza, Joanna A; Jones, Joyce; Sun, Xiangjie; Jang, Yunho; Thor, Sharmi; Belser, Jessica A; Zanders, Natosha; Creager, Hannah M; Ridenour, Callie; Wang, Li; Stark, Thomas J; Garten, Rebecca; Chen, Li-Mei; Barnes, John; Tumpey, Terrence M; Wentworth, David E; Maines, Taronna R; Davis, C Todd

    2018-06-01

    Influenza A(H1) viruses circulating in swine represent an emerging virus threat, as zoonotic infections occur sporadically following exposure to swine. A fatal infection caused by an H1N1 variant (H1N1v) virus was detected in a patient with reported exposure to swine and who presented with pneumonia, respiratory failure, and cardiac arrest. To understand the genetic and phenotypic characteristics of the virus, genome sequence analysis, antigenic characterization, and ferret pathogenesis and transmissibility experiments were performed. Antigenic analysis of the virus isolated from the fatal case, A/Ohio/09/2015, demonstrated significant antigenic drift away from the classical swine H1N1 variant viruses and H1N1 pandemic 2009 viruses. A substitution in the H1 hemagglutinin (G155E) was identified that likely impacted antigenicity, and reverse genetics was employed to understand the molecular mechanism of antibody escape. Reversion of the substitution to 155G, in a reverse genetics A/Ohio/09/2015 virus, showed that this residue was central to the loss of hemagglutination inhibition by ferret antisera raised against a prototypical H1N1 pandemic 2009 virus (A/California/07/2009), as well as gamma lineage classical swine H1N1 viruses, demonstrating the importance of this residue for antibody recognition of this H1 lineage. When analyzed in the ferret model, A/Ohio/09/2015 and another H1N1v virus, A/Iowa/39/2015, as well as A/California/07/2009, replicated efficiently in the respiratory tract of ferrets. The two H1N1v viruses transmitted efficiently among cohoused ferrets, but respiratory droplet transmission studies showed that A/California/07/2009 transmitted through the air more efficiently. Preexisting immunity to A/California/07/2009 did not fully protect ferrets from challenge with A/Ohio/09/2015. IMPORTANCE Human infections with classical swine influenza A(H1N1) viruses that circulate in pigs continue to occur in the United States following exposure to swine. To

  4. Mongrelised genetics of H1N1 virus: A bird′s eyeview

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    Nagarathna C

    2010-01-01

    Full Text Available H1N1 influenza, also known as "novel H1N1 virus" has led to a "global outcry." This virus is more virulent when compared with other seasonal flu viruses. Virulence may change as the adaptive mutation gene increases within the virus. A study at the US Centre for Disease Control and Prevention published in May 2009 found that children had no preexisting immunity to the new strain as they showed no cross-reactive antibody reaction when compared with adults aged 18-64 years, who showed a cross-reactive antibody reaction of 6-9% and older adults with 33% immunity. This review article depicts H1N1 virus, its virulence with genetic evolution potential and preventive protocol for the dental professionals. This would allow us to comprehend the changes in the disease process and contribute in its prevention as "prevention is better than cure."

  5. Early Outbreak of 2009 Influenza A (H1N1) in Mexico Prior to Identification of pH1N1 Virus

    Science.gov (United States)

    Hsieh, Ying-Hen; Ma, Stefan; Velasco Hernandez, Jorge X.; Lee, Vernon J.; Lim, Wei Yen

    2011-01-01

    Background In the aftermath of the global spread of 2009 influenza A (pH1N1) virus, still very little is known of the early stages of the outbreak in Mexico during the early months of the year, before the virus was identified. Methodology/Main Findings We fit a simple mathematical model, the Richards model, to the number of excess laboratory-confirmed influenza cases in Mexico and Mexico City during the first 15 weeks in 2009 over the average influenza case number of the previous five baseline years of 2004-2008 during the same period to ascertain the turning point (or the peak incidence) of a wave of early influenza infections, and to estimate the transmissibility of the virus during these early months in terms of its basic reproduction number. The results indicate that there may have been an early epidemic in Mexico City as well as in all of Mexico during February/March. Based on excess influenza cases, the estimated basic reproduction number R0 for the early outbreak was 1.59 (0.55 to 2.62) for Mexico City during weeks 5–9, and 1.25 (0.76, 1.74) for all of Mexico during weeks 5–14. Conclusions We established the existence of an early epidemic in Mexico City and in all of Mexico during February/March utilizing the routine influenza surveillance data, although the location of seeding is unknown. Moreover, estimates of R0 as well as the time of peak incidence (the turning point) for Mexico City and all of Mexico indicate that the early epidemic in Mexico City in February/March had been more transmissible (larger R0) and peaked earlier than the rest of the country. Our conclusion lends support to the possibility that the virus could have already spread to other continents prior to the identification of the virus and the reporting of lab-confirmed pH1N1 cases in North America in April. PMID:21909366

  6. Infection by rhinovirus: similarity of clinical signs included in the case definition of influenza IAn/H1N1.

    Science.gov (United States)

    de Oña Navarro, Maria; Melón García, Santiago; Alvarez-Argüelles, Marta; Fernández-Verdugo, Ana; Boga Riveiro, Jose Antonio

    2012-08-01

    Although new influenza virus (IAn/H1N1) infections are mild and indistinguishable from any other seasonal influenza virus infections, there are few data on comparisons of the clinical features of infection with (IAn/H1N1) and with other respiratory viruses. The incidence, clinical aspects and temporal distribution of those respiratory viruses circulating during flu pandemic period were studied. Respiratory samples from patients with acute influenza-like symptoms were collected from May 2009 to December 2009. Respiratory viruses were detected by conventional culture methods and genome amplification techniques. Although IAn/H1N1 was the virus most frequently detected, several other respiratory viruses co-circulated with IAn/H1N1 during the pandemic period, especially rhinovirus. The similarity between clinical signs included in the clinical case definition for influenza and those caused by other respiratory viruses, particularly rhinovirus, suggest that a high percentage of viral infections were clinically diagnosed as case of influenza. Our study offers useful information to face future pandemics caused by influenza virus, indicating that differential diagnoses are required in order to not overestimate the importance of the pandemic. Copyright © 2011 Elsevier España, S.L. All rights reserved.

  7. Coinfection with influenza A(H1N1)pdm09 and dengue virus in fatal cases.

    Science.gov (United States)

    Perdigão, Anne Carolinne Bezerra; Ramalho, Izabel Letícia Cavalcante; Guedes, Maria Izabel Florindo; Braga, Deborah Nunes Melo; Cavalcanti, Luciano Pamplona Góes; Melo, Maria Elisabeth Lisboa de; Araújo, Rafael Montenegro de Carvalho; Lima, Elza Gadelha; Silva, Luciene Alexandre Bié da; Araújo, Lia de Carvalho; Araújo, Fernanda Montenegro de Carvalho

    2016-09-01

    We report on four patients with fatal influenza A(H1N1)pdm09 and dengue virus coinfections. Clinical, necropsy and histopathologic findings presented in all cases were characteristic of influenza-dengue coinfections, and all were laboratory-confirmed for both infections. The possibility of influenza and dengue coinfection should be considered in locations where these two viruses' epidemic periods coincide to avoid fatal outcomes. Dengue is a mosquito-borne viral infection caused by one of the four dengue viruses (DENV-1 to 4). Each of these viruses is capable of causing nonspecific febrile illnesses, classic dengue fever and dengue haemorrhagic fever (Gubler 1998). As a result, dengue is often difficult to diagnose clinically, especially because peak dengue season often coincides with that of other common febrile illnesses in tropical regions (Chacon et al. 2015). In April 2009, a new virus, influenza A/H1N1/pandemic (FluA/H1N1/09pdm), caused a severe outbreak in Mexico. The virus quickly spread throughout the world, and in June 2009, the World Health Organization declared a pandemic (WHO 2010). In Brazil, the first laboratory confirmed case of FluA/H1N1/09pdm was in July 2009 (Pires Neto et al. 2013). The state of Ceará, in Northeast Brazil, is a dengue endemic area. In this state, the virus influenza A(H1N1)pdm09 has circulated since 2009, and through the first half of 2012, 11 deaths caused by the virus were confirmed (Pires Neto et al. 2013). The influenza and dengue seasons in Ceará overlap, which led to diagnostic difficulties. We report four cases of laboratory-confirmed coinfection of deadly influenza A(H1N1)pdm09 with DENV, which occurred during the dengue and influenza season in 2012 and 2013 in Ceará.

  8. The Influenza Virus and the 2009 H1N1 Outbreak

    Science.gov (United States)

    2016-04-08

    MDW/SGVU SUBJECT: Professional Presentation Approval 8 APR 2016 1. Your paper, entitled The Influenza Virus and the 2009 HlNl Outbreak presented at...L TO BE PUBLISHED OR PRESENTED The Influenza Virus and the 2009 H1N1 Outbreak 2. FUNDING RECEIVED FOR THIS STUDY? DYES [g] NO FUNDING SOURCE: I I...336:!. ~~ 2 C-; MARKE. COON. :vtajor. USAF Acting Chic!’. Civil I.aw The Influenza Virus and the 2009 H 1 N 1 Outbreak Thomas. F. Gibbons, Ph.D

  9. Coinfection with influenza A(H1N1pdm09 and dengue virus in fatal cases

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    Anne Carolinne Bezerra Perdigão

    2016-01-01

    Full Text Available Abstract We report on four patients with fatal influenza A(H1N1pdm09 and dengue virus coinfections. Clinical, necropsy and histopathologic findings presented in all cases were characteristic of influenza-dengue coinfections, and all were laboratory-confirmed for both infections. The possibility of influenza and dengue coinfection should be considered in locations where these two viruses’ epidemic periods coincide to avoid fatal outcomes. Dengue is a mosquito-borne viral infection caused by one of the four dengue viruses (DENV-1 to 4. Each of these viruses is capable of causing nonspecific febrile illnesses, classic dengue fever and dengue haemorrhagic fever (Gubler 1998. As a result, dengue is often difficult to diagnose clinically, especially because peak dengue season often coincides with that of other common febrile illnesses in tropical regions (Chacon et al. 2015. In April 2009, a new virus, influenza A/H1N1/pandemic (FluA/H1N1/09pdm, caused a severe outbreak in Mexico. The virus quickly spread throughout the world, and in June 2009, the World Health Organization declared a pandemic (WHO 2010. In Brazil, the first laboratory confirmed case of FluA/H1N1/09pdm was in July 2009 (Pires Neto et al. 2013. The state of Ceará, in Northeast Brazil, is a dengue endemic area. In this state, the virus influenza A(H1N1pdm09 has circulated since 2009, and through the first half of 2012, 11 deaths caused by the virus were confirmed (Pires Neto et al. 2013. The influenza and dengue seasons in Ceará overlap, which led to diagnostic difficulties. We report four cases of laboratory-confirmed coinfection of deadly influenza A(H1N1pdm09 with DENV, which occurred during the dengue and influenza season in 2012 and 2013 in Ceará.

  10. Transmission of Hemagglutinin D222G Mutant Strain of Pandemic (H1N1) 2009 Virus

    Science.gov (United States)

    Facchini, Marzia; Spagnolo, Domenico; De Marco, Maria A.; Calzoletti, Laura; Zanetti, Alessandro; Fumagalli, Roberto; Tanzi, Maria L.; Cassone, Antonio; Rezza, Giovanni; Donatelli, Isabella

    2010-01-01

    A pandemic (H1N1) 2009 virus strain carrying the D222G mutation was identified in a severely ill man and was transmitted to a household contact. Only mild illness developed in the contact, despite his obesity and diabetes. The isolated virus reacted fully with an antiserum against the pandemic vaccine strain. PMID:20409386

  11. Genetic Characterization of Influenza A (H1N1) Pandemic 2009 Virus Isolates from Mumbai.

    Science.gov (United States)

    Gohil, Devanshi; Kothari, Sweta; Shinde, Pramod; Meharunkar, Rhuta; Warke, Rajas; Chowdhary, Abhay; Deshmukh, Ranjana

    2017-08-01

    Pandemic influenza A (H1N1) 2009 virus was first detected in India in May 2009 which subsequently became endemic in many parts of the country. Influenza A viruses have the ability to evade the immune response through its ability of antigenic variations. The study aims to characterize influenza A (H1N1) pdm 09 viruses circulating in Mumbai during the pandemic and post-pandemic period. Nasopharyngeal swabs positive for influenza A (H1N1) pdm 09 viruses were inoculated on Madin-Darby canine kidney cell line for virus isolation. Molecular and phylogenetic analysis of influenza A (H1N1) pdm 09 isolates was conducted to understand the evolution and genetic diversity of the strains. Nucleotide and amino acid sequences of the HA gene of Mumbai isolates when compared to A/California/07/2009-vaccine strain revealed 14 specific amino acid differences located at the antigenic sites. Amino acid variations in HA and NA gene resulted in changes in the N-linked glycosylation motif which may lead to immune evasion. Phylogenetic analysis of the isolates revealed their evolutionary position with vaccine strain A/California/07/2009 but had undergone changes gradually. The findings in the present study confirm genetic variability of influenza viruses and highlight the importance of continuous surveillance during influenza outbreaks.

  12. How Does Influenza A (H1N1 Infection Proceed in Allogeneic Stem Cell Transplantation Recipients?

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    Sinem Civriz Bozdağ

    2012-03-01

    Full Text Available Clinical course of H1N1 infection in Allogeneic Hematopoietic Stem Cell Transplantation (AHSCT patients is contraversial. We report three AHSCT patients who were infected with Influenza A/H1N1 infection. All of the patients were diagnosed with different hematological diagnosis and were at different stages of transplantation.All of them were treated with oseltamivir,zanamivir was switched with oseltamivir in one patient. All of the three patients were survived without any complication. Swine flu, can display with different courses and progress with bacterial or other viral infections in immunsupressed patients.

  13. Novel pandemic influenza A(H1N1 viruses are potently inhibited by DAS181, a sialidase fusion protein.

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    Gallen B Triana-Baltzer

    2009-11-01

    Full Text Available The recent emergence of a novel pandemic influenza A(H1N1 strain in humans exemplifies the rapid and unpredictable nature of influenza virus evolution and the need for effective therapeutics and vaccines to control such outbreaks. However, resistance to antivirals can be a formidable problem as evidenced by the currently widespread oseltamivir- and adamantane-resistant seasonal influenza A viruses (IFV. Additional antiviral approaches with novel mechanisms of action are needed to combat novel and resistant influenza strains. DAS181 (Fludase is a sialidase fusion protein in early clinical development with in vitro and in vivo preclinical activity against a variety of seasonal influenza strains and highly pathogenic avian influenza strains (A/H5N1. Here, we use in vitro, ex vivo, and in vivo models to evaluate the activity of DAS181 against several pandemic influenza A(H1N1 viruses.The activity of DAS181 against several pandemic influenza A(H1N1 virus isolates was examined in MDCK cells, differentiated primary human respiratory tract culture, ex-vivo human bronchi tissue and mice. DAS181 efficiently inhibited viral replication in each of these models and against all tested pandemic influenza A(H1N1 strains. DAS181 treatment also protected mice from pandemic influenza A(H1N1-induced pathogenesis. Furthermore, DAS181 antiviral activity against pandemic influenza A(H1N1 strains was comparable to that observed against seasonal influenza virus including the H274Y oseltamivir-resistant influenza virus.The sialidase fusion protein DAS181 exhibits potent inhibitory activity against pandemic influenza A(H1N1 viruses. As inhibition was also observed with oseltamivir-resistant IFV (H274Y, DAS181 may be active against the antigenically novel pandemic influenza A(H1N1 virus should it acquire the H274Y mutation. Based on these and previous results demonstrating DAS181 broad-spectrum anti-IFV activity, DAS181 represents a potential therapeutic agent for

  14. Influenza Virus A (H1N1) in Giant Anteaters (Myrmecophaga tridactyla)

    OpenAIRE

    Nofs, Sally; Abd-Eldaim, Mohamed; Thomas, Kathy V.; Toplon, David; Rouse, Dawn; Kennedy, Melissa

    2009-01-01

    In February 2007, an outbreak of respiratory disease occurred in a group of giant anteaters (Myrmecophaga tridactyla) at the Nashville Zoo. Isolates from 2 affected animals were identified in March 2007 as a type A influenza virus related to human influenza subtype H1N1.

  15. Influenza virus A (H1N1) in giant anteaters (Myrmecophaga tridactyla).

    Science.gov (United States)

    Nofs, Sally; Abd-Eldaim, Mohamed; Thomas, Kathy V; Toplon, David; Rouse, Dawn; Kennedy, Melissa

    2009-07-01

    In February 2007, an outbreak of respiratory disease occurred in a group of giant anteaters (Myrmecophaga tridactyla) at the Nashville Zoo. Isolates from 2 affected animals were identified in March 2007 as a type A influenza virus related to human influenza subtype H1N1.

  16. Positive Selection on Hemagglutinin and Neuraminidase Genes of H1N1 Influenza Viruses

    LENUS (Irish Health Repository)

    Li, Wenfu

    2011-04-21

    Abstract Background Since its emergence in March 2009, the pandemic 2009 H1N1 influenza A virus has posed a serious threat to public health. To trace the evolutionary path of these new pathogens, we performed a selection-pressure analysis of a large number of hemagglutinin (HA) and neuraminidase (NA) gene sequences of H1N1 influenza viruses from different hosts. Results Phylogenetic analysis revealed that both HA and NA genes have evolved into five distinct clusters, with further analyses indicating that the pandemic 2009 strains have experienced the strongest positive selection. We also found evidence of strong selection acting on the seasonal human H1N1 isolates. However, swine viruses from North America and Eurasia were under weak positive selection, while there was no significant evidence of positive selection acting on the avian isolates. A site-by-site analysis revealed that the positively selected sites were located in both of the cleaved products of HA (HA1 and HA2), as well as NA. In addition, the pandemic 2009 strains were subject to differential selection pressures compared to seasonal human, North American swine and Eurasian swine H1N1 viruses. Conclusions Most of these positively and\\/or differentially selected sites were situated in the B-cell and\\/or T-cell antigenic regions, suggesting that selection at these sites might be responsible for the antigenic variation of the viruses. Moreover, some sites were also associated with glycosylation and receptor-binding ability. Thus, selection at these positions might have helped the pandemic 2009 H1N1 viruses to adapt to the new hosts after they were introduced from pigs to humans. Positive selection on position 274 of NA protein, associated with drug resistance, might account for the prevalence of drug-resistant variants of seasonal human H1N1 influenza viruses, but there was no evidence that positive selection was responsible for the spread of the drug resistance of the pandemic H1N1 strains.

  17. New Onset Refractory Status Epilepticus in a Young Man with H1N1 Infection

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    Faisal Ibrahim

    2014-01-01

    Full Text Available Objective. To report a case of refractory status epilepticus (SE as an unusual early manifestation of H1N1 influenza infection. Introduction. H1N1 neurological complications have been reported and consist mainly of seizures or encephalopathy occurring in children. However, we only found a single report of an adult developing complex partial SE with H1N1 infection. Case Report. A 21-year-old previously healthy man was brought to the emergency room (ER after a witnessed generalized tonic clonic seizure (GTCS. He was fully alert and afebrile upon ER arrival, but a second GTCS prompted treatment with Lorazepam and Fosphenytoin. The initial EEG showed diffuse slowing, but a repeat one requested as the patient failed to regain consciousness revealed recurrent focal seizures of independent bihemispheric origin, fulfilling the criteria for nonconvulsive SE. Chest X-ray, followed by chest CT scan, showed a left upper lobe consolidation. H1N1 infection was confirmed with PCR on bronchoalveolar lavage material. Despite aggressive treatment with Midazolam, Propofol, and multiple high dose antiepileptic drugs, the electrographic seizures recurred at every attempt to reduce the intravenous sedative drugs. The patient died two weeks after his initial presentation. Conclusion. H1N1 should be added to the list of rare causes of refractory SE, regardless of the patient’s age.

  18. Novel virus influenza A (H1N1sw in South-Eastern France, April-August 2009.

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    Antoine Nougairède

    Full Text Available BACKGROUND: In April 2009, the first cases of pandemic (H1N1-2009 influenza [H1N1sw] virus were detected in France. Virological surveillance was undertaken in reference laboratories of the seven French Defence Zones. METHODOLOGY/PRINCIPAL FINDINGS: We report results of virological analyses performed in the Public Hospitals of Marseille during the first months of the outbreak. (i Nasal swabs were tested using rapid influenza diagnostic test (RIDT and two RT-PCR assays. Epidemiological characteristics of the 99 first suspected cases were analyzed, including detection of influenza virus and 18 other respiratory viruses. During three months, a total of 1,815 patients were tested (including 236 patients infected H1N1sw virus and distribution in age groups and results of RIDT were analyzed. (ii 600 sera received before April 2009 and randomly selected from in-patients were tested by a standard hemagglutination inhibition assay for antibody to the novel H1N1sw virus. (iii One early (May 2009 and one late (July 2009 viral isolates were characterized by sequencing the complete hemagglutinine and neuraminidase genes. (iiii Epidemiological characteristics of a cluster of cases that occurred in July 2009 in a summer camp were analyzed. CONCLUSIONS/SIGNIFICANCE: This study presents new virological and epidemiological data regarding infection by the pandemic A/H1N1 virus in Europe. Distribution in age groups was found to be similar to that previously reported for seasonal H1N1. The first seroprevalence data made available for a European population suggest a previous exposure of individuals over 40 years old to influenza viruses antigenically related to the pandemic (H1N1-2009 virus. Genomic analysis indicates that strains harbouring a new amino-acid pattern in the neuraminidase gene appeared secondarily and tended to supplant the first strains. Finally, in contrast with previous reports, our data support the use of RIDT for the detection of infection in

  19. Genetic characterization of the influenza A pandemic (H1N1 2009 virus isolates from India.

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    Varsha A Potdar

    Full Text Available BACKGROUND: The Influenza A pandemic H1N1 2009 (H1N1pdm virus appeared in India in May 2009 and thereafter outbreaks with considerable morbidity and mortality have been reported from many parts of the country. Continuous monitoring of the genetic makeup of the virus is essential to understand its evolution within the country in relation to global diversification and to track the mutations that may affect the behavior of the virus. METHODS: H1N1pdm viruses were isolated from both recovered and fatal cases representing major cities and sequenced. Phylogenetic analyses of six concatenated whole genomes and the hemagglutinin (HA gene of seven more isolates from May-September 2009 was performed with reference to 685 whole genomes of global isolates available as of November 24, 2009. Molecular characterization of all the 8 segments was carried out for known pathogenic markers. RESULTS: The first isolate of May 2009 belonged to clade 5. Although clade 7 was the dominant H1N1pdm lineage in India, both clades 6 and 7 were found to be co-circulating. The neuraminidase of all the Indian isolates possessed H275, the marker for sensitivity to the neuraminidase inhibitor Oseltamivir. Some of the mutations in HA are at or in the vicinity of antigenic sites and may therefore be of possible antigenic significance. Among these a D222G mutation in the HA receptor binding domain was found in two of the eight Indian isolates obtained from fatal cases. CONCLUSIONS: The majority of the 13 Indian isolates grouped in the globally most widely circulating H1N1pdm clade 7. Further, correlations of the mutations specific to clade 7 Indian isolates to viral fitness and adaptability in the country remains to be understood. The D222G mutation in HA from isolates of fatal cases needs to be studied for pathogenicity.

  20. A metagenomic analysis of pandemic influenza A (2009 H1N1 infection in patients from North America.

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    Alexander L Greninger

    2010-10-01

    Full Text Available Although metagenomics has been previously employed for pathogen discovery, its cost and complexity have prevented its use as a practical front-line diagnostic for unknown infectious diseases. Here we demonstrate the utility of two metagenomics-based strategies, a pan-viral microarray (Virochip and deep sequencing, for the identification and characterization of 2009 pandemic H1N1 influenza A virus. Using nasopharyngeal swabs collected during the earliest stages of the pandemic in Mexico, Canada, and the United States (n = 17, the Virochip was able to detect a novel virus most closely related to swine influenza viruses without a priori information. Deep sequencing yielded reads corresponding to 2009 H1N1 influenza in each sample (percentage of aligned sequences corresponding to 2009 H1N1 ranging from 0.0011% to 10.9%, with up to 97% coverage of the influenza genome in one sample. Detection of 2009 H1N1 by deep sequencing was possible even at titers near the limits of detection for specific RT-PCR, and the percentage of sequence reads was linearly correlated with virus titer. Deep sequencing also provided insights into the upper respiratory microbiota and host gene expression in response to 2009 H1N1 infection. An unbiased analysis combining sequence data from all 17 outbreak samples revealed that 90% of the 2009 H1N1 genome could be assembled de novo without the use of any reference sequence, including assembly of several near full-length genomic segments. These results indicate that a streamlined metagenomics detection strategy can potentially replace the multiple conventional diagnostic tests required to investigate an outbreak of a novel pathogen, and provide a blueprint for comprehensive diagnosis of unexplained acute illnesses or outbreaks in clinical and public health settings.

  1. Molecular epidemiology of influenza A(H1N1pdm09 viruses from Pakistan in 2009-2010.

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    Uzma Bashir Aamir

    Full Text Available In early 2009, a novel influenza A(H1N1 virus that emerged in Mexico and United States rapidly disseminated worldwide. The spread of this virus caused considerable morbidity with over 18000 recorded deaths. The new virus was found to be a reassortant containing gene segments from human, avian and swine influenza viruses.The first case of human infection with A(H1N1pdm09 in Pakistan was detected on 18(th June 2009. Since then, 262 laboratory-confirmed cases have been detected during various outbreaks with 29 deaths (as of 31(st August 2010. The peak of the epidemic was observed in December with over 51% of total respiratory cases positive for influenza. Representative isolates from Pakistan viruses were sequenced and analyzed antigenically. Sequence analysis of genes coding for surface glycoproteins HA and NA showed high degree of high levels of sequence identity with corresponding genes of regional viruses circulating South East Asia. All tested viruses were sensitive to Oseltamivir in the Neuraminidase Inhibition assays.Influenza A(H1N1pdm09 viruses from Pakistan form a homogenous group of viruses. Their HA genes belong to clade 7 and show antigenic profile similar to the vaccine strain A/California/07/2009. These isolates do not show any amino acid changes indicative of high pathogenicity and virulence. It is imperative to continue monitoring of these viruses for identification of potential variants of high virulence or drug resistance.

  2. In vitro reassortment between endemic H1N2 and 2009 H1N1 pandemic swine influenza viruses generates attenuated viruses.

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    Ben M Hause

    Full Text Available The pandemic H1N1 (pH1N1 influenza virus was first reported in humans in the spring of 2009 and soon thereafter was identified in numerous species, including swine. Reassortant viruses, presumably arising from the co-infection of pH1N1 and endemic swine influenza virus (SIV, were subsequently identified from diagnostic samples collected from swine. In this study, co-infection of swine testicle (ST cells with swine-derived endemic H1N2 (MN745 and pH1N1 (MN432 yielded two reassortant H1N2 viruses (R1 and R2, both possessing a matrix gene derived from pH1N1. In ST cells, the reassortant viruses had growth kinetics similar to the parental H1N2 virus and reached titers approximately 2 log(10 TCID(50/mL higher than the pH1N1 virus, while in A549 cells these viruses had similar growth kinetics. Intranasal challenge of pigs with H1N2, pH1N1, R1 or R2 found that all viruses were capable of infecting and transmitting between direct contact pigs as measured by real time reverse transcription PCR of nasal swabs. Lung samples were also PCR-positive for all challenge groups and influenza-associated microscopic lesions were detected by histology. Interestingly, infectious virus was detected in lung samples for pigs challenged with the parental H1N2 and pH1N1 at levels significantly higher than either reassortant virus despite similar levels of viral RNA. Results of our experiment suggested that the reassortant viruses generated through in vitro cell culture system were attenuated without gaining any selective growth advantage in pigs over the parental lineages. Thus, reassortant influenza viruses described in this study may provide a good system to study genetic basis of the attenuation and its mechanism.

  3. 64 multidetector CT findings of influenza A (H1N1) virus in patients with hematologic malignancies

    International Nuclear Information System (INIS)

    El-Badrawy, Adel; Zeidan, Amany; Ebrahim, Mohamed A.

    2012-01-01

    Background. The pandemic of swine-origin H1N1 influenza that began in early 2009 has provided evidence that radiology can assist in the early diagnosis of severe cases. Immunocompromised patients are at increased risk for morbidity and mortality. MDCT is superior to radiography in showing the distribution of the disease. Purpose. To review the 64 multidetector CT thoracic findings of novel swine-origin influenza A (H1N1) virus in patients with hematologic malignancies. Material and Methods. This study included 12 patients (3 women, 9 men; mean age, 32.2 years). All patients proved to be infected with influenza A (H1N1) virus. The hematologic malignancies were acute myeloid leukemia (n = 8), chronic lymphocytic leukemia (n = 2), multiple myeloma (n = 1), and myelodysplastic syndrome (n = 1). All the patients underwent CT scanning using a 64 multidetector CT scanner. Chest CT scans were reviewed for ground-glass opacities (GGOs), consolidation, airway thickening/dilatation, nodules, mediastinal lymphadenopathy, and pleural effusion. Results. More than one CT finding was detected in every patient. Pulmonary affection was bilateral, more on the left side. The affections were mainly peribronchial. Airway wall thickening and dilatation were detected in all 12 patients, GGO in 9/12 patients, nodules in 6/12 patients, consolidation in 6/12 patients, hilar lymphadenopathy in 3/12 patients, and pleural effusion in 2/12 patients. Conclusion. Acute myeloid leukemia is the most common hematologic malignancy affected by influenza A (H1N1) virus. The left lung is affected more than the right one. The most common multidetector CT findings are unilateral or bilateral airway thickening and dilatation. Multidetector CT can be used for early and accurate assessment of pulmonary affection with influenza A H1N1 virus infection

  4. 64 multidetector CT findings of influenza A (H1N1) virus in patients with hematologic malignancies

    Energy Technology Data Exchange (ETDEWEB)

    El-Badrawy, Adel [Dept. of Radiology, Mansoura Faculty of Medicine, Mansoura (Egypt)], E-mail: adelelbadrawy@hotmail.com; Zeidan, Amany [Dept. of Thoracic Medicine, Mansoura Faculty of Medicine, Mansoura (Egypt); Ebrahim, Mohamed A. [Dept. of Medical Oncology, Mansoura Faculty of Medicine, Mansoura (Egypt)

    2012-07-15

    Background. The pandemic of swine-origin H1N1 influenza that began in early 2009 has provided evidence that radiology can assist in the early diagnosis of severe cases. Immunocompromised patients are at increased risk for morbidity and mortality. MDCT is superior to radiography in showing the distribution of the disease. Purpose. To review the 64 multidetector CT thoracic findings of novel swine-origin influenza A (H1N1) virus in patients with hematologic malignancies. Material and Methods. This study included 12 patients (3 women, 9 men; mean age, 32.2 years). All patients proved to be infected with influenza A (H1N1) virus. The hematologic malignancies were acute myeloid leukemia (n = 8), chronic lymphocytic leukemia (n = 2), multiple myeloma (n = 1), and myelodysplastic syndrome (n = 1). All the patients underwent CT scanning using a 64 multidetector CT scanner. Chest CT scans were reviewed for ground-glass opacities (GGOs), consolidation, airway thickening/dilatation, nodules, mediastinal lymphadenopathy, and pleural effusion. Results. More than one CT finding was detected in every patient. Pulmonary affection was bilateral, more on the left side. The affections were mainly peribronchial. Airway wall thickening and dilatation were detected in all 12 patients, GGO in 9/12 patients, nodules in 6/12 patients, consolidation in 6/12 patients, hilar lymphadenopathy in 3/12 patients, and pleural effusion in 2/12 patients. Conclusion. Acute myeloid leukemia is the most common hematologic malignancy affected by influenza A (H1N1) virus. The left lung is affected more than the right one. The most common multidetector CT findings are unilateral or bilateral airway thickening and dilatation. Multidetector CT can be used for early and accurate assessment of pulmonary affection with influenza A H1N1 virus infection.

  5. Los virus Influenza y la nueva pandemia A/H1N1

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    Miguel Talledo

    2011-07-01

    Full Text Available Los virus Influenza pertenecen a la familia Orthomyxoviridae, virus con genoma RNA de sentido negativo segmentado. Los virus influenza tipo A infectan a humanos y otros organismos, y son los agentes causantes de influenza en humanos. Resaltan entre sus principales proteínas la Hemaglutinina y la Neuraminidasa, que son utilizadas en la clasificación de los miembros de este grupo. Estos virus mutan continuamente, exhibiendo patrones muy estudiados, como el cambio y la deriva antigénica, siendo uno de los principales eventos de recombinación el reordenamiento. Todos los subtipos se encuentran en aves acuáticas silvestres, aunque se han encontrado otros hospederos, como equinos, visones, ballenas, focas, cerdos, gallinas y pavos, entre otros. Tanto las aves salvajes, las aves domésticas y el cerdo juegan un rol fundamental en la adaptación progresiva del virus al hospedero humano. Aunque los subtipos H2N2 y H3N2 han sido muy comunes, el subtipo H1N1 ha reemergido con mutaciones que le han permitido alcanzar el estado de pandemia en 2009. Este nuevo virus surge de un virus generado por triple reordenamiento con el virus humano, porcino norteamericano y aviar, conteniendo a su vez segmentos génicos de virus influenza porcina euroasiática. Esto ha hecho que el virus presente una enfermedad humana moderada y solamente severa y hasta letal en casos de individuos con condiciones médicas previas. A nivel mundial ha causado más de 134,510 casos y en el Perú alcanza cerca de 3,700 casos. El estado actual indica que la pandemia está por llegar a su pico máximo en el Perú, debido a la alta morbilidad del virus coincidente con la estación más fría del año. Es importante contener al máximo la dispersión del virus, ya que cuanto mayor sea el número de personas que infecte, el mismo estará sometido a un mayor número de eventos de recombinación genética por reordenamiento con virus influenza humanos previos y esto puede condicionar a la

  6. Specific Inhibitory Effect of κ-Carrageenan Polysaccharide on Swine Pandemic 2009 H1N1 Influenza Virus.

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    Qiang Shao

    Full Text Available The 2009 influenza A H1N1 pandemic placed unprecedented demands on antiviral drug resources and the vaccine industry. Carrageenan, an extractive of red algae, has been proven to inhibit infection and multiplication of various enveloped viruses. The aim of this study was to examine the ability of κ-carrageenan to inhibit swine pandemic 2009 H1N1 influenza virus to gain an understanding of antiviral ability of κ-carrageenan. It was here demonstrated that κ-carrageenan had no cytotoxicity at concentrations below 1000 μg/ml. Hemagglutination, 50% tissue culture infectious dose (TCID50 and cytopathic effect (CPE inhibition assays showed that κ-carrageenan inhibited A/Swine/Shandong/731/2009 H1N1 (SW731 and A/California/04/2009 H1N1 (CA04 replication in a dose-dependent fashion. Mechanism studies show that the inhibition of SW731 multiplication and mRNA expression was maximized when κ-carrageenan was added before or during adsorption. The result of Hemagglutination inhibition assay indicate that κ-carrageenan specifically targeted HA of SW731 and CA04, both of which are pandemic H1N/2009 viruses, without effect on A/Pureto Rico/8/34 H1N1 (PR8, A/WSN/1933 H1N1 (WSN, A/Swine/Beijing/26/2008 H1N1 (SW26, A/Chicken/Shandong/LY/2008 H9N2 (LY08, and A/Chicken/Shandong/ZB/2007 H9N2 (ZB07 viruses. Immunofluorescence assay and Western blot showed that κ-carrageenan also inhibited SW731 protein expression after its internalization into cells. These results suggest that κ-carrageenan can significantly inhibit SW731 replication by interfering with a few replication steps in the SW731 life cycles, including adsorption, transcription, and viral protein expression, especially interactions between HA and cells. In this way, κ-carrageenan might be a suitable alternative approach to therapy meant to address anti-IAV, which contains an HA homologous to that of SW731.

  7. Primary study on the lesions and specific proteins in BEAS-2B cells induced with the 2009 A (H1N1) influenza virus.

    Science.gov (United States)

    Fang, Shisong; Zhang, Kaining; Wang, Ting; Wang, Xin; Lu, Xing; Peng, Bo; Wu, Weihua; Zhang, Ran; Chen, Shiju; Zhang, Renli; Xue, Hong; Yu, Muhua; Cheng, Jinquan

    2014-12-01

    In order to investigate the lesions and proteins with differential expression in cells infected with the 2009 A (H1N1) virus and to determine the specific proteins involved in cell damage, the present study has been performed. BEAS-2B cells were infected with the 2009 A (H1N1) influenza virus or the seasonal H1N1 influenza virus for 12, 24, 48, and 72 h, and cell cycle and apoptosis were analyzed with flow cytometry. Total cellular proteins were extracted and underwent two-dimensional gel electrophoresis. The differentially expressed proteins underwent mass spectrometry for identification. The results showed that after 12 h, cells infected with the virus strain sourced from severe cases had the highest apoptosis rate (P cells infected with the virus strain sourced from fatal cases and severe cases had the highest apoptosis rate (P cells infected with virus strains from fatal cases and ordinary cases had the highest apoptosis rate (P cell cycle arrest mainly at the G0/G1 phase. Eighteen differentially expressed proteins were identified, including galectin-1, cofilin-1, protein DJ-1, proteasome subunit α type-5, macrophage migration inhibitory factor, translationally controlled tumor protein, profilin 1, and interferon α-2. Galectin-1 was specifically observed in BEAS-2B infected with 2009 A (H1N1) influenza viruses, and cofilin-1 was specifically observed in BEAS-2B cells in the late stage of 2009 A (H1N1) influenza virus infection. In conclusion, differential effects of the 2009 A (H1N1) influenza virus and seasonal H1N1 influenza virus were identified on the cell cycle and apoptosis, and galectin-1 may play a role in cell apoptosis induced by 2009 A (H1N1) influenza virus.

  8. Acute necrotizing encephalopathy in a child with H1N1 influenza infection

    International Nuclear Information System (INIS)

    Lyon, Jane B.; Remigio, Cheryl; Milligan, Thomas; Deline, Carol

    2010-01-01

    Since the World Health Organization declared a global pandemic of novel influenza A H1N1 in June 2009, there has been a sustained rise in the number of cases of this strain of influenza. Although most cases are mild with complete and uneventful recovery, multiple cases of severe infection with complications including death have been reported. To the best of our knowledge, the majority of fatal outcomes in the United States have been related to pulmonary complications. We report a 12-year-old girl infected with influenza A H1N1 whose clinical course was complicated by rapid progressive neurologic deterioration and striking CT and MRI findings consistent with acute necrotizing encephalopathy (ANE). To our knowledge this has not been reported in the pediatric radiology literature. We hope this case will alert radiologists to this complication and familiarize radiologists with imaging findings that herald ANE. (orig.)

  9. Asymptomatic ratio for seasonal H1N1 influenza infection among schoolchildren in Taiwan.

    Science.gov (United States)

    Hsieh, Ying-Hen; Tsai, Chen-An; Lin, Chien-Yu; Chen, Jin-Hua; King, Chwan-Chuen; Chao, Day-Yu; Cheng, Kuang-Fu

    2014-02-12

    Studies indicate that asymptomatic infections do indeed occur frequently for both seasonal and pandemic influenza, accounting for about one-third of influenza infections. Studies carried out during the 2009 pH1N1 pandemic have found significant antibody response against seasonal H1N1 and H3N2 vaccine strains in schoolchildren receiving only pandemic H1N1 monovalent vaccine, yet reported either no symptoms or only mild symptoms. Serum samples of 255 schoolchildren, who had not received vaccination and had pre-season HI Ab serotiters definition of Fever + (cough or sore throat or nose) + ( headache or pain or fatigue). Asymptomatic ratio for children is found to be substantially higher than that of the general population in literature. In providing reasonable quantification of the asymptomatic infected children spreading pathogens to others in a seasonal epidemic or a pandemic, our estimates of symptomatic ratio of infected children has important clinical and public health implications.

  10. Epidemiology of Travel-associated Pandemic (H1N1) 2009 Infection in 116 Patients, Singapore

    OpenAIRE

    Mukherjee, Pratik; Lim, Poh Lian; Chow, Angela; Barkham, Timothy; Seow, Eillyne; Win, Mar Kyaw; Chua, Arlene; Leo, Yee Sin; Chen, Mark I-Cheng

    2010-01-01

    In June 2009, during Singapore?s pandemic influenza plan containment phase, pandemic (H1N1) 2009 was introduced into the country through imported cases. To understand how travel patterns affected the initial outbreak, we examined epidemiologic and travel data for the first 116 case-patients admitted to Tan Tock Seng Hospital, Singapore, with travel-associated infection. Sixty-one percent and 54% of patients, respectively, met US Centers for Disease Control and Prevention and World Health Orga...

  11. The transmissibility and control of pandemic influenza A (H1N1) virus.

    Science.gov (United States)

    Yang, Yang; Sugimoto, Jonathan D; Halloran, M Elizabeth; Basta, Nicole E; Chao, Dennis L; Matrajt, Laura; Potter, Gail; Kenah, Eben; Longini, Ira M

    2009-10-30

    Pandemic influenza A (H1N1) 2009 (pandemic H1N1) is spreading throughout the planet. It has become the dominant strain in the Southern Hemisphere, where the influenza season has now ended. Here, on the basis of reported case clusters in the United States, we estimated the household secondary attack rate for pandemic H1N1 to be 27.3% [95% confidence interval (CI) from 12.2% to 50.5%]. From a school outbreak, we estimated that a typical schoolchild infects 2.4 (95% CI from 1.8 to 3.2) other children within the school. We estimated the basic reproductive number, R0, to range from 1.3 to 1.7 and the generation interval to range from 2.6 to 3.2 days. We used a simulation model to evaluate the effectiveness of vaccination strategies in the United States for fall 2009. If a vaccine were available soon enough, vaccination of children, followed by adults, reaching 70% overall coverage, in addition to high-risk and essential workforce groups, could mitigate a severe epidemic.

  12. Information Needs and Seeking Behavior During the H1N1 Virus Outbreak

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    Majid, Shaheen

    2013-03-01

    Full Text Available Timely access to quality healthcare information during an outbreak plays an important role in curtailing its spread. The aim of this study was to investigate the information needs and seeking behavior of the general public in Singapore during the H1N1 pandemic. A pre-tested questionnaire was used for data collection. The convenience snowball sampling method was used and 260 working adults and tertiary-level students participated in this study. The most crucial information needs of a majority of the participants were: symptoms of H1N1, causes of the infection, preventive measures, and possible treatments. Data analysis also revealed that mass media such as television, newspapers, and radio were most frequently used for seeking the needed information. The use of human information sources was also quite high while only a small number of the respondents accessed online news and healthcare websites. About three-quarters of the participants indicated that the gathered information helped them to stay vigilant and take necessary precautionary measures. A major problem identified by the participants in using H1N1 information was the lack of understanding of certain terms used in public communications. This paper suggests certain measures for strengthening health information communication during future outbreaks.

  13. Infection of the upper respiratory tract with seasonal influenza A(H3N2) virus induces protective immunity in ferrets against infection with A(H1N1)pdm09 virus after intranasal, but not intratracheal, inoculation

    NARCIS (Netherlands)

    R. Bodewes (Rogier); J.H.C.M. Kreijtz (Joost); G. van Amerongen (Geert); M.L.B. Hillaire (Marine); S.E. Vogelzang-van Trierum (Stella ); N. Nieuwkoop; P. van Run (Peter); T. Kuiken (Thijs); R.A.M. Fouchier (Ron); A.D.M.E. Osterhaus (Albert); G.F. Rimmelzwaan (Guus)

    2013-01-01

    textabstractThe clinical symptoms caused by infection with influenza A virusvary widely and depend on the strain causing the infection, the dose and route of inoculation, and the presence of preexisting immunity. In most cases, seasonal influenza A viruses cause relatively mild upper respiratory

  14. The 2009 A (H1N1) influenza virus pandemic: A review.

    Science.gov (United States)

    Girard, Marc P; Tam, John S; Assossou, Olga M; Kieny, Marie Paule

    2010-07-12

    In March and early April 2009 a new swine-origin influenza virus (S-OIV), A (H1N1), emerged in Mexico and the USA. The virus quickly spread worldwide through human-to-human transmission. In view of the number of countries and communities which were reporting human cases, the World Health Organization raised the influenza pandemic alert to the highest level (level 6) on June 11, 2009. The propensity of the virus to primarily affect children, young adults and pregnant women, especially those with an underlying lung or cardiac disease condition, and the substantial increase in rate of hospitalizations, prompted the efforts of the pharmaceutical industry, including new manufacturers from China, Thailand, India and South America, to develop pandemic H1N1 influenza vaccines. All currently registered vaccines were tested for safety and immunogenicity in clinical trials on human volunteers. All were found to be safe and to elicit potentially protective antibody responses after the administration of a single dose of vaccine, including split inactivated vaccines with or without adjuvant, whole-virion vaccines and live-attenuated vaccines. The need for an increased surveillance of influenza virus circulation in swine is outlined. Copyright 2010. Published by Elsevier Ltd.

  15. Detection of extensive cross-neutralization between pandemic and seasonal A/H1N1 Influenza Viruses using a pseudotype neutralization assay.

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    Béatrice Labrosse

    Full Text Available BACKGROUND: Cross-immunity between seasonal and pandemic A/H1N1 influenza viruses remains uncertain. In particular, the extent that previous infection or vaccination by seasonal A/H1N1 viruses can elicit protective immunity against pandemic A/H1N1 is unclear. METHODOLOGY/PRINCIPAL FINDINGS: Neutralizing titers against seasonal A/H1N1 (A/Brisbane/59/2007 and against pandemic A/H1N1 (A/California/04/2009 were measured using an HIV-1-based pseudovirus neutralization assay. Using this highly sensitive assay, we found that a large fraction of subjects who had never been exposed to pandemic A/H1N1 express high levels of pandemic A/H1N1 neutralizing titers. A significant correlation was seen between neutralization of pandemic A/H1N1 and neutralization of a standard seasonal A/H1N1 strain. Significantly higher pandemic A/H1N1 neutralizing titers were measured in subjects who had received vaccination against seasonal influenza in 2008-2009. Higher pandemic neutralizing titers were also measured in subjects over 60 years of age. CONCLUSIONS/SIGNIFICANCE: Our findings reveal that the extent of protective cross-immunity between seasonal and pandemic A/H1N1 influenza viruses may be more important than previously estimated. This cross-immunity could provide a possible explanation of the relatively mild profile of the recent influenza pandemic.

  16. Evidence of cross-reactive immunity to 2009 pandemic influenza A virus in workers seropositive to swine H1N1 influenza viruses circulating in Italy.

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    Maria A De Marco

    Full Text Available BACKGROUND: Pigs play a key epidemiologic role in the ecology of influenza A viruses (IAVs emerging from animal hosts and transmitted to humans. Between 2008 and 2010, we investigated the health risk of occupational exposure to swine influenza viruses (SIVs in Italy, during the emergence and spread of the 2009 H1N1 pandemic (H1N1pdm virus. METHODOLOGY/PRINCIPAL FINDINGS: Serum samples from 123 swine workers (SWs and 379 control subjects (Cs, not exposed to pig herds, were tested by haemagglutination inhibition (HI assay against selected SIVs belonging to H1N1 (swH1N1, H1N2 (swH1N2 and H3N2 (swH3N2 subtypes circulating in the study area. Potential cross-reactivity between swine and human IAVs was evaluated by testing sera against recent, pandemic and seasonal, human influenza viruses (H1N1 and H3N2 antigenic subtypes. Samples tested against swH1N1 and H1N1pdm viruses were categorized into sera collected before (n. 84 SWs; n. 234 Cs and after (n. 39 SWs; n. 145 Cs the pandemic peak. HI-antibody titers ≥10 were considered positive. In both pre-pandemic and post-pandemic peak subperiods, SWs showed significantly higher swH1N1 seroprevalences when compared with Cs (52.4% vs. 4.7% and 59% vs. 9.7%, respectively. Comparable HI results were obtained against H1N1pdm antigen (58.3% vs. 7.7% and 59% vs. 31.7%, respectively. No differences were found between HI seroreactivity detected in SWs and Cs against swH1N2 (33.3% vs. 40.4% and swH3N2 (51.2 vs. 55.4% viruses. These findings indicate the occurrence of swH1N1 transmission from pigs to Italian SWs. CONCLUSION/SIGNIFICANCE: A significant increase of H1N1pdm seroprevalences occurred in the post-pandemic peak subperiod in the Cs (p<0.001 whereas SWs showed no differences between the two subperiods, suggesting a possible occurrence of cross-protective immunity related to previous swH1N1 infections. These data underline the importance of risk assessment and occupational health surveillance activities aimed

  17. Pandemic influenza A H1N1 2009 infection versus vaccination: a cohort study comparing immune responses in pregnancy.

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    Barbra M Fisher

    Full Text Available BACKGROUND: With the emergence of H1N1 pandemic (pH1N1 influenza, the CDC recommended that pregnant women be one of five initial target groups to receive the 2009 monovalent H1N1 vaccine, regardless of prior infection with this influenza strain. We sought to compare the immune response of pregnant women to H1N1 infection versus vaccination and to determine the extent of passive immunity conferred to the newborn. METHODS/FINDINGS: During the 2009-2010 influenza season, we enrolled a cohort of women who either had confirmed pH1N1 infection during pregnancy, did not have pH1N1 during pregnancy but were vaccinated against pH1N1, or did not have illness or vaccination. Maternal and umbilical cord venous blood samples were collected at delivery. Hemagglutination inhibition assays (HAI for pH1N1 were performed. Data were analyzed using linear regression analyses. HAIs were performed for matched maternal/cord blood pairs for 16 women with confirmed pH1N1 infection, 14 women vaccinated against pH1N1, and 10 women without infection or vaccination. We found that pH1N1 vaccination and wild-type infection during pregnancy did not differ with respect to (1 HAI titers at delivery, (2 HAI antibody decay slopes over time, and (3 HAI titers in the cord blood. CONCLUSIONS: Vaccination against pH1N1 confers a similar HAI antibody response as compared to pH1N1 infection during pregnancy, both in quantity and quality. Illness or vaccination during pregnancy confers passive immunity to the newborn.

  18. H1N1 influenza infection in children: Frequency, pattern, and outcome of chest radiographic abnormalities

    International Nuclear Information System (INIS)

    Yoo, S.-Y.; Kim, J.H.; Eo, H.; Jeon, T.Y.; Shin, K.E.; Shin, W.S.; Jung, H.N.; Kim, Y.-J.

    2011-01-01

    Aim: To describe the frequency, pattern, and outcome of chest radiographic abnormalities in children with H1N1 influenza infection. Materials and methods: Three hundred and fourteen paediatric patients with confirmed H1N1 influenza infection who underwent chest radiography at presentation at a single institution during the outbreak in 2009 were retrospectively reviewed. Abnormal chest radiographic findings related to acute infection were analysed in terms of frequency, pattern, and distribution. Medical records and follow-up radiographs were also reviewed to assess clinical features and outcomes. Results: Chest lesions suggesting acute infection were identified in 49 (16%) patients (mean age 8.2 years, range approximately 1.8-18.5 years). The most common finding was prominent peribronchial marking (71%), followed by air-space opacity (51%) with or without volume decrease, generalized hyperinflation (24%), and pleural effusion (20%). Other minor findings included pneumomediastinum (n = 2) and a nodule (n = 1). Distributions were bilateral (55%) or unilateral (45%) with frequent involvement of lower (78%), and middle (59%) lung zones. Thirty-nine patients (80%) were hospitalized and six (12%) required mechanical ventilation, followed by recovery. Thirty-one out of the 33 patients that underwent follow-up radiography showed marked resolution of all radiographic abnormalities. Conclusion: The frequency of a chest radiographic abnormality was found to be low in children with H1N1 influenza infection. Although typical radiographic findings of a viral lower respiratory infection were more common, unilateral involvement and air-space opacity were common, often with pleural effusion. Furthermore, pulmonary lesions showed near complete resolution on follow-up radiographs in the majority of patients.

  19. H1N1 influenza infection in children: Frequency, pattern, and outcome of chest radiographic abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, S.-Y. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, J.H., E-mail: jhkate@skku.ed [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Eo, H.; Jeon, T.Y.; Shin, K.E.; Shin, W.S.; Jung, H.N. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Y.-J. [Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2011-04-15

    Aim: To describe the frequency, pattern, and outcome of chest radiographic abnormalities in children with H1N1 influenza infection. Materials and methods: Three hundred and fourteen paediatric patients with confirmed H1N1 influenza infection who underwent chest radiography at presentation at a single institution during the outbreak in 2009 were retrospectively reviewed. Abnormal chest radiographic findings related to acute infection were analysed in terms of frequency, pattern, and distribution. Medical records and follow-up radiographs were also reviewed to assess clinical features and outcomes. Results: Chest lesions suggesting acute infection were identified in 49 (16%) patients (mean age 8.2 years, range approximately 1.8-18.5 years). The most common finding was prominent peribronchial marking (71%), followed by air-space opacity (51%) with or without volume decrease, generalized hyperinflation (24%), and pleural effusion (20%). Other minor findings included pneumomediastinum (n = 2) and a nodule (n = 1). Distributions were bilateral (55%) or unilateral (45%) with frequent involvement of lower (78%), and middle (59%) lung zones. Thirty-nine patients (80%) were hospitalized and six (12%) required mechanical ventilation, followed by recovery. Thirty-one out of the 33 patients that underwent follow-up radiography showed marked resolution of all radiographic abnormalities. Conclusion: The frequency of a chest radiographic abnormality was found to be low in children with H1N1 influenza infection. Although typical radiographic findings of a viral lower respiratory infection were more common, unilateral involvement and air-space opacity were common, often with pleural effusion. Furthermore, pulmonary lesions showed near complete resolution on follow-up radiographs in the majority of patients.

  20. Efficacy of a pandemic (H1N1) 2009 virus vaccine in pigs against the pandemic influenza virus is superior to commercially available swine influenza vaccines.

    Science.gov (United States)

    Loeffen, W L A; Stockhofe, N; Weesendorp, E; van Zoelen-Bos, D; Heutink, R; Quak, S; Goovaerts, D; Heldens, J G M; Maas, R; Moormann, R J; Koch, G

    2011-09-28

    In April 2009 a new influenza A/H1N1 strain, currently named "pandemic (H1N1) influenza 2009" (H1N1v), started the first official pandemic in humans since 1968. Several incursions of this virus in pig herds have also been reported from all over the world. Vaccination of pigs may be an option to reduce exposure of human contacts with infected pigs, thereby preventing cross-species transfer, but also to protect pigs themselves, should this virus cause damage in the pig population. Three swine influenza vaccines, two of them commercially available and one experimental, were therefore tested and compared for their efficacy against an H1N1v challenge. One of the commercial vaccines is based on an American classical H1N1 influenza strain, the other is based on a European avian H1N1 influenza strain. The experimental vaccine is based on reassortant virus NYMC X179A (containing the hemagglutinin (HA) and neuraminidase (NA) genes of A/California/7/2009 (H1N1v) and the internal genes of A/Puerto Rico/8/34 (H1N1)). Excretion of infectious virus was reduced by 0.5-3 log(10) by the commercial vaccines, depending on vaccine and sample type. Both vaccines were able to reduce virus replication especially in the lower respiratory tract, with less pathological lesions in vaccinated and subsequently challenged pigs than in unvaccinated controls. In pigs vaccinated with the experimental vaccine, excretion levels of infectious virus in nasal and oropharyngeal swabs, were at or below 1 log(10)TCID(50) per swab and lasted for only 1 or 2 days. An inactivated vaccine containing the HA and NA of an H1N1v is able to protect pigs from an infection with H1N1v, whereas swine influenza vaccines that are currently available are of limited efficaciousness. Whether vaccination of pigs against H1N1v will become opportune remains to be seen and will depend on future evolution of this strain in the pig population. Close monitoring of the pig population, focussing on presence and evolution of

  1. Neuraminidase and hemagglutinin matching patterns of a highly pathogenic avian and two pandemic H1N1 influenza A viruses.

    Directory of Open Access Journals (Sweden)

    Yonghui Zhang

    Full Text Available BACKGROUND: Influenza A virus displays strong reassortment characteristics, which enable it to achieve adaptation in human infection. Surveying the reassortment and virulence of novel viruses is important in the prevention and control of an influenza pandemic. Meanwhile, studying the mechanism of reassortment may accelerate the development of anti-influenza strategies. METHODOLOGY/PRINCIPAL FINDINGS: The hemagglutinin (HA and neuraminidase (NA matching patterns of two pandemic H1N1 viruses (the 1918 and current 2009 strains and a highly pathogenic avian influenza A virus (H5N1 were studied using a pseudotyped particle (pp system. Our data showed that four of the six chimeric HA/NA combinations could produce infectious pps, and that some of the chimeric pps had greater infectivity than did their ancestors, raising the possibility of reassortment among these viruses. The NA of H5N1 (A/Anhui/1/2005 could hardly reassort with the HAs of the two H1N1 viruses. Many biological characteristics of HA and NA, including infectivity, hemagglutinating ability, and NA activity, are dependent on their matching pattern. CONCLUSIONS/SIGNIFICANCE: Our data suggest the existence of an interaction between HA and NA, and the HA NA matching pattern is critical for valid viral reassortment.

  2. Comparative evaluation of acute respiratory distress syndrome in patients with and without H1N1 infection at a tertiary care referral center

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    Tanvir Samra

    2011-01-01

    Full Text Available H1N1 subtype of influenza A virus has clinical presentation ranging from mild flu like illness to severe lung injury and acute respiratory distress syndrome (ARDS. The aim of our study was to compare the demographic characteristics, clinical presentation, and mortality of critically ill patients with (H1N1+ and without H1N1 infection (H1N1-. We retrospectively analyzed medical charts of patients admitted in "Swine Flu ICU" with ARDS from August 2009 to May 2010. Real-time reverse transcriptase polymerase chain reaction (RT-PCR assay was used for detection of H1N1 virus in the respiratory specimens. Clinical data from 106 (H1N1 , 45; H1N1+, 61 patients was collected and compared. Mean delay in presentation to our hospital was 5.7 ± 3.1 days and co-morbidities were present in two-fifth of the total admissions. Sequential Organ Failure Assessment (SOFA score of patients with and without H1N1 infection was comparable; 7.8 ± 3.5 and 6.6 ± 3.1 on day 1 and 7.2 ± 4.5 and 6.5 ± 3.1 on day 3, respectively. H1N1+ patients were relatively younger in age (34.2 ± 12.9 years vs. 42.8 ± 18.1, P = 0.005 but presented with significantly lower PaO 2 :FiO 2 ratio (87.3 ± 48.7 vs. 114 ± 51.7 in comparison to those who subsequently tested as H1N1 . The total leucocyte counts were significantly lower in H1N1+ patients during the first four days of illness but incidence of renal failure (P = 0.02 was higher in H1N1+ patients. The mortality in both the groups was high (H1N1+, 77%; H1N1, 68% but comparable. There was a mean delay of 5.7 ± 3.1 days in initiation of antivirals. Patients with H1N1 infection were relatively younger in age and with a significantly higher incidence of refractory hypoxia and acute renal failure. Mortality from ARDS reported in our study in both the groups was high but comparable.

  3. From where did the 2009 'swine-origin' influenza A virus (H1N1 emerge?

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    Armstrong John S

    2009-11-01

    Full Text Available Abstract The swine-origin influenza A (H1N1 virus that appeared in 2009 and was first found in human beings in Mexico, is a reassortant with at least three parents. Six of the genes are closest in sequence to those of H1N2 'triple-reassortant' influenza viruses isolated from pigs in North America around 1999-2000. Its other two genes are from different Eurasian 'avian-like' viruses of pigs; the NA gene is closest to H1N1 viruses isolated in Europe in 1991-1993, and the MP gene is closest to H3N2 viruses isolated in Asia in 1999-2000. The sequences of these genes do not directly reveal the immediate source of the virus as the closest were from isolates collected more than a decade before the human pandemic started. The three parents of the virus may have been assembled in one place by natural means, such as by migrating birds, however the consistent link with pig viruses suggests that human activity was involved. We discuss a published suggestion that unsampled pig herds, the intercontinental live pig trade, together with porous quarantine barriers, generated the reassortant. We contrast that suggestion with the possibility that laboratory errors involving the sharing of virus isolates and cultured cells, or perhaps vaccine production, may have been involved. Gene sequences from isolates that bridge the time and phylogenetic gap between the new virus and its parents will distinguish between these possibilities, and we suggest where they should be sought. It is important that the source of the new virus be found if we wish to avoid future pandemics rather than just trying to minimize the consequences after they have emerged. Influenza virus is a very significant zoonotic pathogen. Public confidence in influenza research, and the agribusinesses that are based on influenza's many hosts, has been eroded by several recent events involving the virus. Measures that might restore confidence include establishing a unified international administrative

  4. Imaging Findings in Patients With H1N1 Influenza A Infection

    International Nuclear Information System (INIS)

    Bakhshayeshkaram, Mehrdad; Saidi, Bahareh; Tabarsi, Payam; Zahirifard, Soheila; Ghofrani, Mishka

    2011-01-01

    Swine influenza (H1N1) is a very contagious respiratory infection and World Health Organization (WHO) has raised the alert level to phase 6 (pandemic). The study of clinical and laboratory manifestations as well as radiologic imaging findings helps in its early diagnosis. The aim of this study was to evaluate the imaging findings of patients with documented H1N1 infection referred to our center. Thirty-one patients (16 men) with documented H1N1 infection were included in our study. The initial radiography obtained from the patients was reviewed regarding pattern (consolidation, ground glass, nodules and reticulation), distribution (focal, multifocal, and diffuse) and the lung zones involved. Computed tomography (CT) scans were also reviewed for the same abnormalities. The patient files were studied for their possible underlying diseases. The mean age was 37.97 ± 13.9 years. Seventeen (54.8%) patients had co-existing condition (eight respiratory, five cardiovascular, two immunodeficiency, two cancer, four others). Twelve (38.7%) patients required intensive care unit (ICU) admission. Five (16.1%) patients died. (25.8%) had normal initial radiographs. The most common abnormality was consolidation (12/31; 38.7%) in the peripheral region (11/31; 35.5%) followed by peribronchovascular areas (10/31; 32.3%) which was most commonly observed in the lower zone. The patients admitted to the ICU were more likely to have two or more lung zones involved (P = 0.005). In patients with the novel swine flu infection, the most common radiographic abnormality observed was consolidation in the lower lung zones. Patients admitted to ICU were more likely to have two or more lung zones involved

  5. Mutations in polymerase genes enhanced the virulence of 2009 pandemic H1N1 influenza virus in mice.

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    Wenfei Zhu

    Full Text Available Influenza A virus can infect a wide variety of animal species with illness ranging from mild to severe, and is a continual cause for concern. Genetic mutations that occur either naturally or during viral adaptation in a poorly susceptible host are key mechanisms underlying the evolution and virulence of influenza A virus. Here, the variants containing PA-A36T or PB2-H357N observed in the mouse-adapted descendants of 2009 pandemic H1N1 virus (pH1N1, A/Sichuan/1/2009 (SC, were characterized. Both mutations enhanced polymerase activity in mammalian cells. These effects were confirmed using recombinant SC virus containing polymerase genes with wild type (WT or mutant PA or PB2. The PA-A36T mutant showed enhanced growth property compared to the WT in both human A549 cells and porcine PK15 cells in vitro, without significant effect on viral propagation in murine LA-4 cells and pathogenicity in mice; however, it did enhance the lung virus titer. PB2-H357N variant demonstrated growth ability comparable to the WT in A549 cells, but replicated well in PK15, LA-4 cells and in mice with an enhanced pathogenic phenotype. Despite such mutations are rare in nature, they could be observed in avian H5 and H7 subtype viruses which were currently recognized to pose potential threat to human. Our findings indicated that pH1N1 may adapt well in mammals when acquiring these mutations. Therefore, future molecular epidemiological surveillance should include scrutiny of both markers because of their potential impact on pathogenesis.

  6. Mannose-binding lectin contributes to deleterious inflammatory response in pandemic H1N1 and avian H9N2 infection.

    Science.gov (United States)

    Ling, Man To; Tu, Wenwei; Han, Yan; Mao, Huawei; Chong, Wai Po; Guan, Jing; Liu, Ming; Lam, Kwok Tai; Law, Helen K W; Peiris, J S Malik; Takahashi, K; Lau, Yu Lung

    2012-01-01

    Mannose-binding lectin (MBL) is a pattern-recognition molecule, which functions as a first line of host defense. Pandemic H1N1 (pdmH1N1) influenza A virus caused massive infection in 2009 and currently circulates worldwide. Avian influenza A H9N2 (H9N2/G1) virus has infected humans and has the potential to be the next pandemic virus. Antiviral function and immunomodulatory role of MBL in pdmH1N1 and H9N2/G1 virus infection have not been investigated. In this study, MBL wild-type (WT) and MBL knockout (KO) murine models were used to examine the role of MBL in pdmH1N1 and H9N2/G1 virus infection. Our study demonstrated that in vitro, MBL binds to pdmH1N1 and H9N2/G1 viruses, likely via the carbohydrate recognition domain of MBL. Wild-type mice developed more severe disease, as evidenced by a greater weight loss than MBL KO mice during influenza virus infection. Furthermore, MBL WT mice had enhanced production of proinflammatory cytokines and chemokines compared with MBL KO mice, suggesting that MBL could upregulate inflammatory responses that may potentially worsen pdmH1N1 and H9N2/G1 virus infections. Our study provided the first in vivo evidence that MBL may be a risk factor during pdmH1N1 and H9N2/G1 infection by upregulating proinflammatory response.

  7. Clinical and epidemiologic characteristics of an outbreak of novel H1N1 (swine origin) influenza A virus among United States military beneficiaries.

    Science.gov (United States)

    Crum-Cianflone, Nancy F; Blair, Patrick J; Faix, Dennis; Arnold, John; Echols, Sara; Sherman, Sterling S; Tueller, John E; Warkentien, Tyler; Sanguineti, Gabriela; Bavaro, Mary; Hale, Braden R

    2009-12-15

    A novel swine-origin influenza A (H1N1) virus was identified in March 2009 and subsequently caused worldwide outbreaks. The San Diego region was an early focal point of the emerging pandemic. We describe the clinical and epidemiologic characteristics of this novel strain in a military population to assist in future outbreak prevention and control efforts. We performed an epidemiologic evaluation of novel H1N1 virus infections diagnosed in San Diego County among 96,258 local US military beneficiaries. The structured military medical system afforded the ability to obtain precise epidemiologic information on the impact on H1N1 virus infection in a population. The novel H1N1 virus was confirmed using real-time reverse transcriptase polymerase chain reaction (rRT-PCR). From 21 April through 8 May 2009, 761 patients presented with influenza-like illness and underwent rRT-PCR testing. Of these patients, 97 had confirmed novel H1N1 virus infection, with an incidence rate of 101 cases per 100,000 persons. The median age of H1N1 patients with H1N1 virus infection was 21 years (interquartile range, 15-25 years). Fever was a universal symptom in patients with H1N1 virus infection; other symptoms included cough (present in 96% of patients), myalgia or arthralgia (57%), and sore throat (51%). Sixty-eight (70%) of our patients had an identifiable epidemiologic link to another confirmed patient. The largest cluster of cases of H1N1 virus infection occurred on a Navy ship and involved 32 (8%) of 402 crew members; the secondary attack rate was 6%-14%. The rapid influenza testing that was used during this outbreak had a sensitivity of 51% and specificity of 98%, compared with rRT-PCR. Only 1 patient was hospitalized, and there were no deaths. A novel H1N1 influenza A virus caused a significant outbreak among military beneficiaries in San Diego County, including a significant cluster of cases onboard a Navy ship. The outbreak described here primarily affected adolescents and young

  8. Central nervous system manifestations in pediatric patients with influenza A H1N1 infection during the 2009 pandemic.

    Science.gov (United States)

    Wilking, Ashley N; Elliott, Elizabeth; Garcia, Melissa N; Murray, Kristy O; Munoz, Flor M

    2014-09-01

    A novel H1N1 influenza A virus (A(H1N1)pdm09) particularly affected individuals central nervous system complications associated with pandemic influenza in the pediatric population. Retrospective review of patients with laboratory-confirmed influenza A(H1N1)pdm09 infection and central nervous system manifestations at Texas Children's Hospital between April 2009 and June 2010. Among 365 patients with influenza A(H1N1)pdm09, 32 (8.8%) had central nervous system manifestations at a median age of 4 years. Eight (25.0%) were previously healthy, and 12 (37.5%) had neurological pre-existing conditions. Of the 32 cases of influenza with neurological complications, seizure (n = 17; 53.1%) was the most common central nervous system manifestation, followed by encephalitis (n = 4; 12.5%), meningitis (n = 4; 12.5%), encephalopathy (n = 3; 9.4%), meningismus (n = 3; 9.4%), focal hemorrhagic brain lesions (n = 2; 6.3%), brain infarction (n = 1; 3.1%), and sensorineural hearing loss (n = 1; 3.1%). Two patients demonstrated two or more types of central nervous system complications. One patient had abnormal cerebrospinal fluid with pleocytosis. Almost two thirds of the children with central nervous system manifestations required intensive care unit admission and nearly half required mechanical ventilation. There were no deaths. Patients with pre-existing neurological conditions were at greater risk for central nervous system manifestations during pandemic influenza infection. Patients with central nervous system manifestations were more likely to experience severe illness, characterized by intensive care unit admission and mechanical ventilation, although overall outcomes were good. Influenza prevention in patients with underlying medical conditions, particularly those with neurological conditions, is important. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Systems-level comparison of host responses induced by pandemic and seasonal influenza A H1N1 viruses in primary human type I-like alveolar epithelial cells in vitro

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    Guan Yi

    2010-10-01

    Full Text Available Abstract Background Pandemic influenza H1N1 (pdmH1N1 virus causes mild disease in humans but occasionally leads to severe complications and even death, especially in those who are pregnant or have underlying disease. Cytokine responses induced by pdmH1N1 viruses in vitro are comparable to other seasonal influenza viruses suggesting the cytokine dysregulation as seen in H5N1 infection is not a feature of the pdmH1N1 virus. However a comprehensive gene expression profile of pdmH1N1 in relevant primary human cells in vitro has not been reported. Type I alveolar epithelial cells are a key target cell in pdmH1N1 pneumonia. Methods We carried out a comprehensive gene expression profiling using the Affymetrix microarray platform to compare the transcriptomes of primary human alveolar type I-like alveolar epithelial cells infected with pdmH1N1 or seasonal H1N1 virus. Results Overall, we found that most of the genes that induced by the pdmH1N1 were similarly regulated in response to seasonal H1N1 infection with respect to both trend and extent of gene expression. These commonly responsive genes were largely related to the interferon (IFN response. Expression of the type III IFN IL29 was more prominent than the type I IFN IFNβ and a similar pattern of expression of both IFN genes was seen in pdmH1N1 and seasonal H1N1 infection. Genes that were significantly down-regulated in response to seasonal H1N1 but not in response to pdmH1N1 included the zinc finger proteins and small nucleolar RNAs. Gene Ontology (GO and pathway over-representation analysis suggested that these genes were associated with DNA binding and transcription/translation related functions. Conclusions Both seasonal H1N1 and pdmH1N1 trigger similar host responses including IFN-based antiviral responses and cytokine responses. Unlike the avian H5N1 virus, pdmH1N1 virus does not have an intrinsic capacity for cytokine dysregulation. The differences between pdmH1N1 and seasonal H1N1 viruses

  10. Defining Moments in MMWR History: Swine Influenza A (H1N1) Infection in Two Children, Southern California, March-April 2009

    Centers for Disease Control (CDC) Podcasts

    In 2009, novel influenza A H1N1 virus infection in two children from southern California was first identified. This marked the beginning of the 2009 H1N1 influenza pandemic. MMWR was the first scientific publication to break the news of these cases and went on to publish critical findings from the pandemic. In this podcast, Dr. Dan Jernigan discusses this historic public health event.

  11. A duplex real-time RT-PCR assay for detecting H5N1 avian influenza virus and pandemic H1N1 influenza virus

    OpenAIRE

    Kang, Xiao-ping; Jiang, Tao; Li, Yong-qiang; Lin, Fang; Liu, Hong; Chang, Guo-hui; Zhu, Qing-yu; Qin, E-de; Qin, Cheng-feng; Yang, Yin-hui

    2010-01-01

    Abstract A duplex real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay was improved for simultaneous detection of highly pathogenic H5N1 avian influenza virus and pandemic H1N1 (2009) influenza virus, which is suitable for early diagnosis of influenza-like patients and for epidemiological surveillance. The sensitivity of this duplex real-time RT-PCR assay was 0.02 TCID50 (50% tissue culture infective dose) for H5N1 and 0.2 TCID50 for the pandemic H1N1, which was the same a...

  12. A novel monoclonal antibody effective against lethal challenge with swine-lineage and 2009 pandemic H1N1 influenza viruses in mice

    Science.gov (United States)

    The HA protein of the 2009 pandemic H1N1viruses (14 H1N1pdm) is antigenically closely related to the HA of classical North American swine H1N1 influenza viruses (cH1N1). Since 1998, through reassortment and incorporation of HA genes from human H3N2 and H1N1 influenza viruses, swine influenza strains...

  13. Characterization of an artificial swine-origin influenza virus with the same gene combination as H1N1/2009 virus: a genesis clue of pandemic strain.

    Science.gov (United States)

    Zhao, Xueli; Sun, Yipeng; Pu, Juan; Fan, Lihong; Shi, Weimin; Hu, Yanxin; Yang, Jun; Xu, Qi; Wang, Jingjing; Hou, Dongjun; Ma, Guangpeng; Liu, Jinhua

    2011-01-01

    Pandemic H1N1/2009 influenza virus, derived from a reassortment of avian, human, and swine influenza viruses, possesses a unique gene segment combination that had not been detected previously in animal and human populations. Whether such a gene combination could result in the pathogenicity and transmission as H1N1/2009 virus remains unclear. In the present study, we used reverse genetics to construct a reassortant virus (rH1N1) with the same gene combination as H1N1/2009 virus (NA and M genes from a Eurasian avian-like H1N1 swine virus and another six genes from a North American triple-reassortant H1N2 swine virus). Characterization of rH1N1 in mice showed that this virus had higher replicability and pathogenicity than those of the seasonal human H1N1 and Eurasian avian-like swine H1N1 viruses, but was similar to the H1N1/2009 and triple-reassortant H1N2 viruses. Experiments performed on guinea pigs showed that rH1N1 was not transmissible, whereas pandemic H1N1/2009 displayed efficient transmissibility. To further determine which gene segment played a key role in transmissibility, we constructed a series of reassortants derived from rH1N1 and H1N1/2009 viruses. Direct contact transmission studies demonstrated that the HA and NS genes contributed to the transmission of H1N1/2009 virus. Second, the HA gene of H1N1/2009 virus, when combined with the H1N1/2009 NA gene, conferred efficient contact transmission among guinea pigs. The present results reveal that not only gene segment reassortment but also amino acid mutation were needed for the generation of the pandemic influenza virus.

  14. Characterization of an artificial swine-origin influenza virus with the same gene combination as H1N1/2009 virus: a genesis clue of pandemic strain.

    Directory of Open Access Journals (Sweden)

    Xueli Zhao

    Full Text Available Pandemic H1N1/2009 influenza virus, derived from a reassortment of avian, human, and swine influenza viruses, possesses a unique gene segment combination that had not been detected previously in animal and human populations. Whether such a gene combination could result in the pathogenicity and transmission as H1N1/2009 virus remains unclear. In the present study, we used reverse genetics to construct a reassortant virus (rH1N1 with the same gene combination as H1N1/2009 virus (NA and M genes from a Eurasian avian-like H1N1 swine virus and another six genes from a North American triple-reassortant H1N2 swine virus. Characterization of rH1N1 in mice showed that this virus had higher replicability and pathogenicity than those of the seasonal human H1N1 and Eurasian avian-like swine H1N1 viruses, but was similar to the H1N1/2009 and triple-reassortant H1N2 viruses. Experiments performed on guinea pigs showed that rH1N1 was not transmissible, whereas pandemic H1N1/2009 displayed efficient transmissibility. To further determine which gene segment played a key role in transmissibility, we constructed a series of reassortants derived from rH1N1 and H1N1/2009 viruses. Direct contact transmission studies demonstrated that the HA and NS genes contributed to the transmission of H1N1/2009 virus. Second, the HA gene of H1N1/2009 virus, when combined with the H1N1/2009 NA gene, conferred efficient contact transmission among guinea pigs. The present results reveal that not only gene segment reassortment but also amino acid mutation were needed for the generation of the pandemic influenza virus.

  15. Large Scale Genome Analysis Shows that the Epitopes for Broadly Cross-Reactive Antibodies Are Predominant in the Pandemic 2009 Influenza Virus A H1N1 Strain

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    Edgar E. Lara-Ramírez

    2013-11-01

    Full Text Available The past pandemic strain H1N1 (A (H1N1pdm09 has now become a common component of current seasonal influenza viruses. It has changed the pre-existing immunity of the human population to succeeding infections. In the present study, a total of 14,210 distinct sequences downloaded from National Center for Biotechnology Information (NCBI database were used for the analysis. The epitope compositions in A (H1N1pdm09, classic seasonal strains, swine strains as well as highly virulent avian strain H5N1, identified with the aid of the Immune Epitope DataBase (IEDB, were compared at genomic level. The result showed that A (H1N1 pdm09 contains the 90% of B-cell epitopes for broadly cross-reactive antibodies (EBCA, which is in consonance with the recent reports on the experimental identification of new epitopes or antibodies for this virus and the binding tests with influenza virus protein HA of different subtypes. Our analysis supports that high proportional EBCA depends on the epitope pattern of A (H1N1pdm09 virus. This study may be helpful for better understanding of A (H1N1pdm09 and the production of new influenza vaccines.

  16. Changes in the viral distribution pattern after the appearance of the novel influenza A H1N1 (pH1N1) virus in influenza-like illness patients in Peru.

    Science.gov (United States)

    Laguna-Torres, Victor Alberto; Gómez, Jorge; Aguilar, Patricia V; Ampuero, Julia S; Munayco, Cesar; Ocaña, Víctor; Pérez, Juan; Gamero, María E; Arrasco, Juan Carlos; Paz, Irmia; Chávez, Edward; Cruz, Rollin; Chavez, Jaime; Mendocilla, Silvia; Gomez, Elizabeth; Antigoni, Juana; Gonzalez, Sofía; Tejada, Cesar; Chowell, Gerardo; Kochel, Tadeusz J

    2010-07-27

    We describe the temporal variation in viral agents detected in influenza like illness (ILI) patients before and after the appearance of the ongoing pandemic influenza A (H1N1) (pH1N1) in Peru between 4-January and 13-July 2009. At the health centers, one oropharyngeal swab was obtained for viral isolation. From epidemiological week (EW) 1 to 18, at the US Naval Medical Research Center Detachment (NMRCD) in Lima, the specimens were inoculated into four cell lines for virus isolation. In addition, from EW 19 to 28, the specimens were also analyzed by real time-polymerase-chain-reaction (rRT-PCR). We enrolled 2,872 patients: 1,422 cases before the appearance of the pH1N1 virus, and 1,450 during the pandemic. Non-pH1N1 influenza A virus was the predominant viral strain circulating in Peru through (EW) 18, representing 57.8% of the confirmed cases; however, this predominance shifted to pH1N1 (51.5%) from EW 19-28. During this study period, most of pH1N1 cases were diagnosed in the capital city (Lima) followed by other cities including Cusco and Trujillo. In contrast, novel influenza cases were essentially absent in the tropical rain forest (jungle) cities during our study period. The city of Iquitos (Jungle) had the highest number of influenza B cases and only one pH1N1 case. The viral distribution in Peru changed upon the introduction of the pH1N1 virus compared to previous months. Although influenza A viruses continue to be the predominant viral pathogen, the pH1N1 virus predominated over the other influenza A viruses.

  17. Changes in the viral distribution pattern after the appearance of the novel influenza A H1N1 (pH1N1 virus in influenza-like illness patients in Peru.

    Directory of Open Access Journals (Sweden)

    Victor Alberto Laguna-Torres

    Full Text Available BACKGROUND: We describe the temporal variation in viral agents detected in influenza like illness (ILI patients before and after the appearance of the ongoing pandemic influenza A (H1N1 (pH1N1 in Peru between 4-January and 13-July 2009. METHODS: At the health centers, one oropharyngeal swab was obtained for viral isolation. From epidemiological week (EW 1 to 18, at the US Naval Medical Research Center Detachment (NMRCD in Lima, the specimens were inoculated into four cell lines for virus isolation. In addition, from EW 19 to 28, the specimens were also analyzed by real time-polymerase-chain-reaction (rRT-PCR. RESULTS: We enrolled 2,872 patients: 1,422 cases before the appearance of the pH1N1 virus, and 1,450 during the pandemic. Non-pH1N1 influenza A virus was the predominant viral strain circulating in Peru through (EW 18, representing 57.8% of the confirmed cases; however, this predominance shifted to pH1N1 (51.5% from EW 19-28. During this study period, most of pH1N1 cases were diagnosed in the capital city (Lima followed by other cities including Cusco and Trujillo. In contrast, novel influenza cases were essentially absent in the tropical rain forest (jungle cities during our study period. The city of Iquitos (Jungle had the highest number of influenza B cases and only one pH1N1 case. CONCLUSIONS: The viral distribution in Peru changed upon the introduction of the pH1N1 virus compared to previous months. Although influenza A viruses continue to be the predominant viral pathogen, the pH1N1 virus predominated over the other influenza A viruses.

  18. Preventive Activity against Influenza (H1N1 Virus by Intranasally Delivered RNA-Hydrolyzing Antibody in Respiratory Epithelial Cells of Mice

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    Seungchan Cho

    2015-09-01

    Full Text Available The antiviral effect of a catalytic RNA-hydrolyzing antibody, 3D8 scFv, for intranasal administration against avian influenza virus (H1N1 was described. The recombinant 3D8 scFv protein prevented BALB/c mice against H1N1 influenza virus infection by degradation of the viral RNA genome through its intrinsic RNA-hydrolyzing activity. Intranasal administration of 3D8 scFv (50 μg/day for five days prior to infection demonstrated an antiviral activity (70% survival against H1N1 infection. The antiviral ability of 3D8 scFv to penetrate into epithelial cells from bronchial cavity via the respiratory mucosal layer was confirmed by immunohistochemistry, qRT-PCR, and histopathological examination. The antiviral activity of 3D8 scFv against H1N1 virus infection was not due to host immune cytokines or chemokines, but rather to direct antiviral RNA-hydrolyzing activity of 3D8 scFv against the viral RNA genome. Taken together, our results suggest that the RNase activity of 3D8 scFv, coupled with its ability to penetrate epithelial cells through the respiratory mucosal layer, directly prevents H1N1 virus infection in a mouse model system.

  19. Influenza A/H1N1/2009 virus - experience of the clinical microbiology laboratory of the “L. Sacco” University Hospital in Milan

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    Lisa Lucia Chenal

    2011-06-01

    Full Text Available In the spring of 2009, a new variant of influenza A/H1N1 virus that had never been isolated before, was identified. From April 27 to December 31, 2009 the respiratory samples of 974 patients, obtained from suspected cases of pandemic influenza A virus infection, were analyzed at the Clinical Microbiology Laboratory of the “L. Sacco” University Hospital in Milan. The diagnosis of influenza A/H1N1 infection was performed initially through the use of different molecular biological methods: Seeplex® RV12 ACE Detection (Seegene, NUCLISENS® EASYQ® INFLUENZA A/B (bioMérieux, Influenza A/B Q-PCR Alert (Nanogen running in parallel with rRT-PCR (CDC to confirm the positivity to the new influenza virus, then was used a single specific test, Fast set H1N1v (Arrow Diagnostics. Retrospective study of data showed that 293 (30.1% patients were positive for the new strain of influenza A/H1N1 virus and 8 (0.8% for influenza A other than H1N1 virus.The distribution of influenza A/H1N1 cases showed two peaks, one on July (62.9% and the other one on October (36%, moreover we observed that 155 patients (53% out of 293 positive for influenza A/H1N1 virus aged under 20 years old. The first positivity peak was found in travelers and the second one, occurred 2-3 months prior to the classic seasonal epidemic influenza, was attributed to autochthonous cases , by which the virus had spread worldwide. The highest proportion of cases were among subjects aged from 0 to 20 years and, over this age the positivity rate decreased proportionally with increasing age, in agreement with data reported in other countries.

  20. Dynamics of a New Strain of the H1N1 Influenza A Virus Incorporating the Effects of Repetitive Contacts

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    Puntani Pongsumpun

    2014-01-01

    Full Text Available The respiratory disease caused by the Influenza A Virus is occurring worldwide. The transmission for new strain of the H1N1 Influenza A virus is studied by formulating a SEIQR (susceptible, exposed, infected, quarantine, and recovered model to describe its spread. In the present model, we have assumed that a fraction of the infected population will die from the disease. This changes the mathematical equations governing the transmission. The effect of repetitive contact is also included in the model. Analysis of the model by using standard dynamical modeling method is given. Conditions for the stability of equilibrium state are given. Numerical solutions are presented for different values of parameters. It is found that increasing the amount of repetitive contacts leads to a decrease in the peak numbers of exposed and infectious humans. A stability analysis shows that the solutions are robust.

  1. Clinical characteristics and outcomes among pediatric patients hospitalized with pandemic influenza A/H1N1 2009 infection

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    Eun Lee

    2011-08-01

    Full Text Available Purpose : The purpose of this article is to describe the clinical and epidemiologic features and outcomes among children hospitalized with pandemic influenza A/H1N1 2009 infection. Methods : We retrospectively reviewed the charts of hospitalized pediatric patients (&lt;18 years diagnosed with pandemic influenza A/H1N1 2009 infection by reverse-transcriptase polymerase chain reaction at a tertiary hospital in Seoul, Korea, between September 2009 and February 2010. Results : A total of 72 children were hospitalized with pandemic influenza A/H1N1 2009 infection (median age, 6.0 years; range, 2 months to 18 years. A total of 40% had at least 1 underlying medical condition, including asthma (17%, malignancies (19%, and heart diseases (17%. Of the 72 patients, 54 (76% children admitted with H1N1 infection showed radiographic alterations compatible with pneumonia. There was no significant difference in pre-existing conditions between pandemic influenza A/H1N1 infected patients with or without pneumonia. Children with pandemic influenza A/ H1N1 pneumonia were more likely to have a lower lymphocyte ratio (P=0.02, higher platelet count (P=0.02, and higher level of serum glucose (P=0.003, and more commonly presented with dyspnea than did those without pneumonia (P=0.04. Conclusion : No significant differences in age, sex, or presence of preexisting conditions were found between children hospitalized with pandemic influenza A/H1N1 H1N1 influenza infection with pneumonia and those without pneumonia. Higher leukocyte count, higher glucose level, and a lower lymphocyte ratio were associated with the development of pandemic A/H1N1 2009 influenza pneumonia.

  2. PD-L1 Expression Induced by the 2009 Pandemic Influenza A(H1N1 Virus Impairs the Human T Cell Response

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    Nuriban Valero-Pacheco

    2013-01-01

    Full Text Available PD-L1 expression plays a critical role in the impairment of T cell responses during chronic infections; however, the expression of PD-L1 on T cells during acute viral infections, particularly during the pandemic influenza virus (A(H1N1pdm09, and its effects on the T cell response have not been widely explored. We found that A(H1N1pdm09 virus induced PD-L1 expression on human dendritic cells (DCs and T cells, as well as PD-1 expression on T cells. PD-L1 expression impaired the T cell response against A(H1N1pdm09 by promoting CD8+ T cell death and reducing cytokine production. Furthermore, we found increased PD-L1 expression on DCs and T cells from influenza-infected patients from the first and second 2009 pandemic waves in Mexico City. PD-L1 expression on CD8+ T cells correlated inversely with T cell proportions in patients infected with A(H1N1pdm09. Therefore, PD-L1 expression on DCs and T cells could be associated with an impaired T cell response during acute infection with A(H1N1pdm09 virus.

  3. Adoption of preventive measures during and after the 2009 influenza A (H1N1) virus pandemic peak in Spain.

    Science.gov (United States)

    Agüero, Fernando; Adell, Manel Nebot; Pérez Giménez, Anna; López Medina, María José; Garcia Continente, Xavier

    2011-09-01

    This study describes the preventive measures adopted by the Spanish population towards 2009 influenza A (H1N1) virus and their associated factors. An anonymous computer-assisted telephone interview survey was conducted in Spain in December 2009 and February 2010. Respondents were asked about their perceptions of influenza A (H1N1) virus and the preventive measures adopted. Factors associated with the adoption of preventive measures were assessed by logistic regression analyses. Out of 4892 households approached, 1627 valid responses were obtained (response rate of 33.3%). The most commonly adopted preventive measures were respiratory hygiene and hand washing. Factors independently associated with the adoption of the preventive measures recommended by the Spanish Ministry of Health were female gender, higher educational level, size of municipality of residence >50,000 inhabitants, high perceived susceptibility to infection, high perceived effectiveness of the measures and high perceived usefulness of the information provided by the government. The presence of school-aged children in household was associated with purchasing masks and hand sanitizer. In addition to demographic factors, modifiable factors such as personal beliefs and expectations play a role in the adoption of preventive measures. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Low adherence to influenza vaccination campaigns: is the H1N1 virus pandemic to be blamed?

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    Trivellin Valeria

    2011-11-01

    Full Text Available Abstract Background Over the last few months, debates about the handling of the influenza virus A (H1N1 pandemic took place, in particular regarding the change of the WHO pandemic definition, economic interests, the dramatic communication style of mass media. The activation of plans to reduce the virus diffusion resulted in an important investment of resources. Were those investments proportionate to the risk? Was the pandemic overrated? The workload of the Pediatric Emergency Room (P.E.R. at a teaching hospital in Varese (Northern Italy was investigated in order to evaluate the local diffusion and severity of the new H1N1 influenza epidemic. Discussion A 100% increase of the number of P.E.R. visits, particularly for influenza-like illness, was recorded during weeks 42-46 of 2009 (October, 17 to November, 2; the low rate of hospitalization and the mild presentation of the infection gave rise to the conclusion that the pandemic risk was overrated. Mass media communications concerning the new virus created a disproportionate fear in the population that significantly enhanced the burden of cares at the hospital. In the absence of generally implemented measures for etiological diagnosis, the actual incidence of the H1N1 infection could not be estimated. Virus identification, in fact, was limited to children showing severe symptoms after consultancy with an infectious disease specialist. The alarming nature of the communication campaign and the choice to limit etiologic diagnosis to severe cases created a climate of uncertainty which significantly contributed to the massive admissions to the P.E.R.. Summary The communication strategy adopted by the mass media was an important element during the pandemic: the absence of clarity contributed to the spread of a pandemic phobia that appeared to result more from the sensationalism of the campaign than from infection with the novel influenza A variant of human, avian, swine origin virus. One relevant effect

  5. Long term immune responses to pandemic influenza A/H1N1 infection in solid organ transplant recipients.

    Directory of Open Access Journals (Sweden)

    Aliyah Baluch

    Full Text Available In solid organ transplant (SOT recipients it is unknown if natural infection with influenza confers protection from re-infection with the same strain during the next influenza season. The purpose of this study was to determine if infection with pandemic influenza A/H1N1 (pH1N1 resulted in a long-term immunologic response. Transplant recipients with microbiologically proven pH1N1 infection in 2009/2010 underwent humoral and cell-mediated immunity (CMI testing for pH1N1 just prior to the next influenza season. Concurrent testing for A/Brisbane/59/2007 was done to rule-out cross-reacting antibody. We enrolled 22 adult transplant patients after pH1N1 infection. Follow up testing was done at a median of 7.4 months (range 5.8-15.4 after infection. After excluding those with cross-reactive antibody, 7/19 (36.8% patients were seroprotected. Detectable pH1N1-specific CD4+ and CD8+ interferon-γ producing T-cells were found in 11/22 (50% and 8/22 (36.4% patients respectively. Humoral immunity had a significant correlation with a CD4 response. This is the first study in transplant patients to evaluate long-term humoral and cellular response after natural influenza infection. We show that a substantial proportion of SOT recipients with previous pH1N1 infection lack long-term humoral and cellular immune responses to pH1N1. These patients most likely are at risk for re-infection.

  6. High-resolution computed tomography findings from adult patients with Influenza A (H1N1) virus-associated pneumonia

    International Nuclear Information System (INIS)

    Marchiori, Edson; Zanetti, Glaucia; Hochhegger, Bruno; Rodrigues, Rosana Souza; Fontes, Cristina Asvolinsque Pantaleao; Nobre, Luiz Felipe; Dias Mancano, Alexandre; Meirelles, Gustavo; Irion, Klaus Loureiro

    2010-01-01

    Objective: The aim of this study was to assess the high-resolution computed tomography (HRCT) findings at presentation in patients diagnosed with Influenza A (H1N1) virus-associated pneumonia. Materials and methods: We reviewed the HRCT findings from 20 patients diagnosed with Influenza A (H1N1) and compared their HRCT scans with chest radiographs, obtained on the same day. The imaging studies were obtained 4-9 days after the onset of symptoms. The patients included 11 men and 9 women (ages 24-62 years; mean 42.7 years). All patients had a body temperature greater than 100.4 deg. F (>38 deg. C), tachypnea, and cough. Other common symptoms included diarrhea (60%) and sore throat (30%). The radiographs and HRCT scans were reviewed independently by two observers who reached a consensus decision. Results: The predominant HRCT findings consisted of bilateral ground-glass opacities (n = 12), bilateral areas of consolidation (n = 2), or a mixed bilateral pattern of ground-glass opacities and areas of consolidation (n = 6). The abnormalities were bilateral in all of the 20 patients, had a predominantly sub-pleural distribution in 13 patients, and had a random distribution in the remaining 7 patients. The predominant radiographic findings were consolidations. Normal radiographs were found in 4 out of the 20 patients. Conclusion: HRCT may reveal parenchymal abnormalities in patients with Influenza A (H1N1) infection who have normal findings on radiographs. The predominant HRCT findings were bilateral, peripheral, ground-glass opacities and/or bilateral areas of consolidation. The patients who presented consolidations had more severe clinical course.

  7. High-resolution computed tomography findings from adult patients with Influenza A (H1N1) virus-associated pneumonia

    Energy Technology Data Exchange (ETDEWEB)

    Marchiori, Edson [Fluminense Federal University, Rio de Janeiro (Brazil); Federal University of Rio de Janeiro, Rio de Janeiro (Brazil)], E-mail: edmarchiori@gmail.com; Zanetti, Glaucia [Federal University of Rio de Janeiro, Rio de Janeiro (Brazil)], E-mail: glauciazanetti@gmail.com; Hochhegger, Bruno [Federal University of Rio de Janeiro, Rio de Janeiro (Brazil)], E-mail: brunohochhegger@gmail.com; Rodrigues, Rosana Souza [Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); D' OR Institute for Research and Education, Rio de Janeiro (Brazil)], E-mail: rosana.souzarodrigues@gmail.com; Fontes, Cristina Asvolinsque Pantaleao [Fluminense Federal University, Rio de Janeiro (Brazil)], E-mail: cristinasvolinsque@gmail.com; Nobre, Luiz Felipe [Santa Catarina Federal University, Florianopolis (Brazil)], E-mail: luizfelipenobresc@gmail.com; Dias Mancano, Alexandre [Anchieta Hospital, Taguatinga, DF (Brazil)], E-mail: alex.manzano1@gmail.com; Meirelles, Gustavo [Sao Paulo Federal University, Sao Paulo (Brazil)], E-mail: gmeirelles@gmail.com; Irion, Klaus Loureiro [Liverpool Heart and Chest Hospital NHS Trust, Liverpool (United Kingdom); Royal Liverpool and Broadgreen University Hospital NHS, Liverpool (United Kingdom)], E-mail: klaus.irion@btinternet.com

    2010-04-15

    Objective: The aim of this study was to assess the high-resolution computed tomography (HRCT) findings at presentation in patients diagnosed with Influenza A (H1N1) virus-associated pneumonia. Materials and methods: We reviewed the HRCT findings from 20 patients diagnosed with Influenza A (H1N1) and compared their HRCT scans with chest radiographs, obtained on the same day. The imaging studies were obtained 4-9 days after the onset of symptoms. The patients included 11 men and 9 women (ages 24-62 years; mean 42.7 years). All patients had a body temperature greater than 100.4 deg. F (>38 deg. C), tachypnea, and cough. Other common symptoms included diarrhea (60%) and sore throat (30%). The radiographs and HRCT scans were reviewed independently by two observers who reached a consensus decision. Results: The predominant HRCT findings consisted of bilateral ground-glass opacities (n = 12), bilateral areas of consolidation (n = 2), or a mixed bilateral pattern of ground-glass opacities and areas of consolidation (n = 6). The abnormalities were bilateral in all of the 20 patients, had a predominantly sub-pleural distribution in 13 patients, and had a random distribution in the remaining 7 patients. The predominant radiographic findings were consolidations. Normal radiographs were found in 4 out of the 20 patients. Conclusion: HRCT may reveal parenchymal abnormalities in patients with Influenza A (H1N1) infection who have normal findings on radiographs. The predominant HRCT findings were bilateral, peripheral, ground-glass opacities and/or bilateral areas of consolidation. The patients who presented consolidations had more severe clinical course.

  8. Efficacy of a pandemic (H1N1) 2009 virus vaccine in pigs against the pandemic influenza virus is superior to commercially available swine influenza vaccines.

    NARCIS (Netherlands)

    Loeffen, W.L.A.; Stockhofe-Zurwieden, N.; Weesendorp, E.; Zoelen-Bos, van D.J.; Heutink, R.; Quak, J.; Goovaerts, D.; Heldens, J.; Maas, H.A.; Moormann, R.J.M.; Koch, G.

    2011-01-01

    In April 2009 a new influenza A/H1N1 strain, currently named “pandemic (H1N1) influenza 2009¿ (H1N1v), started the first official pandemic in humans since 1968. Several incursions of this virus in pig herds have also been reported from all over the world. Vaccination of pigs may be an option to

  9. Comparative pathogenesis of an avian H5N2 and a swine H1N1 influenza virus in pigs.

    Directory of Open Access Journals (Sweden)

    Annebel De Vleeschauwer

    2009-08-01

    Full Text Available Pigs are considered intermediate hosts for the transmission of avian influenza viruses (AIVs to humans but the basic organ pathogenesis of AIVs in pigs has been barely studied. We have used 42 four-week-old influenza naive pigs and two different inoculation routes (intranasal and intratracheal to compare the pathogenesis of a low pathogenic (LP H5N2 AIV with that of an H1N1 swine influenza virus. The respiratory tract and selected extra-respiratory tissues were examined for virus replication by titration, immunofluorescence and RT-PCR throughout the course of infection. Both viruses caused a productive infection of the entire respiratory tract and epithelial cells in the lungs were the major target. Compared to the swine virus, the AIV produced lower virus titers and fewer antigen positive cells at all levels of the respiratory tract. The respiratory part of the nasal mucosa in particular showed only rare AIV positive cells and this was associated with reduced nasal shedding of the avian compared to the swine virus. The titers and distribution of the AIV varied extremely between individual pigs and were strongly affected by the route of inoculation. Gross lung lesions and clinical signs were milder with the avian than with the swine virus, corresponding with lower viral loads in the lungs. The brainstem was the single extra-respiratory tissue found positive for virus and viral RNA with both viruses. Our data do not reject the theory of the pig as an intermediate host for AIVs, but they suggest that AIVs need to undergo genetic changes to establish full replication potential in pigs. From a biomedical perspective, experimental LP H5 AIV infection of pigs may be useful to examine heterologous protection provided by H5 vaccines or other immunization strategies, as well as for further studies on the molecular pathogenesis and neurotropism of AIVs in mammals.

  10. Genetic makeup of amantadine-resistant and oseltamivir-resistant human influenza A/H1N1 viruses.

    Science.gov (United States)

    Zaraket, Hassan; Saito, Reiko; Suzuki, Yasushi; Baranovich, Tatiana; Dapat, Clyde; Caperig-Dapat, Isolde; Suzuki, Hiroshi

    2010-04-01

    The emergence and widespread occurrence of antiviral drug-resistant seasonal human influenza A viruses, especially oseltamivir-resistant A/H1N1 virus, are major concerns. To understand the genetic background of antiviral drug-resistant A/H1N1 viruses, we performed full genome sequencing of prepandemic A/H1N1 strains. Seasonal influenza A/H1N1 viruses, including antiviral-susceptible viruses, amantadine-resistant viruses, and oseltamivir-resistant viruses, obtained from several areas in Japan during the 2007-2008 and 2008-2009 influenza seasons were analyzed. Sequencing of the full genomes of these viruses was performed, and the phylogenetic relationships among the sequences of each individual genome segment were inferred. Reference genome sequences from the Influenza Virus Resource database were included to determine the closest ancestor for each segment. Phylogenetic analysis revealed that the oseltamivir-resistant strain evolved from a reassortant oseltamivir-susceptible strain (clade 2B) which circulated in the 2007-2008 season by acquiring the H275Y resistance-conferring mutation in the NA gene. The oseltamivir-resistant lineage (corresponding to the Northern European resistant lineage) represented 100% of the H1N1 isolates from the 2008-2009 season and further acquired at least one mutation in each of the polymerase basic protein 2 (PB2), polymerase basic protein 1 (PB1), hemagglutinin (HA), and neuraminidase (NA) genes. Therefore, a reassortment event involving two distinct oseltamivir-susceptible lineages, followed by the H275Y substitution in the NA gene and other mutations elsewhere in the genome, contributed to the emergence of the oseltamivir-resistant lineage. In contrast, amantadine-resistant viruses from the 2007-2008 season distinctly clustered in clade 2C and were characterized by extensive amino acid substitutions across their genomes, suggesting that a fitness gap among its genetic components might have driven these mutations to maintain it in the

  11. Toward a method for tracking virus evolutionary trajectory applied to the pandemic H1N1 2009 influenza virus.

    Science.gov (United States)

    Squires, R Burke; Pickett, Brett E; Das, Sajal; Scheuermann, Richard H

    2014-12-01

    In 2009 a novel pandemic H1N1 influenza virus (H1N1pdm09) emerged as the first official influenza pandemic of the 21st century. Early genomic sequence analysis pointed to the swine origin of the virus. Here we report a novel computational approach to determine the evolutionary trajectory of viral sequences that uses data-driven estimations of nucleotide substitution rates to track the gradual accumulation of observed sequence alterations over time. Phylogenetic analysis and multiple sequence alignments show that sequences belonging to the resulting evolutionary trajectory of the H1N1pdm09 lineage exhibit a gradual accumulation of sequence variations and tight temporal correlations in the topological structure of the phylogenetic trees. These results suggest that our evolutionary trajectory analysis (ETA) can more effectively pinpoint the evolutionary history of viruses, including the host and geographical location traversed by each segment, when compared against either BLAST or traditional phylogenetic analysis alone. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Comparison of temporal and spatial dynamics of seasonal H3N2, pandemic H1N1 and highly pathogenic avian influenza H5N1 virus infections in ferrets

    NARCIS (Netherlands)

    J.M.A. van den Brand (Judith); K.J. Stittelaar (Koert); G. van Amerongen (Geert); L.A. Reperant (Leslie); L. de Waal (Leon); A.D.M.E. Osterhaus (Albert); T. Kuiken (Thijs)

    2012-01-01

    textabstractHumans may be infected by different influenza A viruses-seasonal, pandemic, and zoonotic-which differ in presentation from mild upper respiratory tract disease to severe and sometimes fatal pneumonia with extra-respiratory spread. Differences in spatial and temporal dynamics of these

  13. Insights from investigating the interactions of adamantane-based drugs with the M2 proton channel from the H1N1 swine virus

    International Nuclear Information System (INIS)

    Wang, Jing-Fang; Wei, Dong-Qing; Chou, Kuo-Chen

    2009-01-01

    The M2 proton channel is one of indispensable components for the influenza A virus that plays a vital role in its life cycle and hence is an important target for drug design against the virus. In view of this, the three-dimensional structure of the H1N1-M2 channel was developed based on the primary sequence taken from a patient recently infected by the H1N1 (swine flu) virus. With an explicit water-membrane environment, molecular docking studies were performed for amantadine and rimantadine, the two commercial drugs generally used to treat influenza A infection. It was found that their binding affinity to the H1N1-M2 channel is significantly lower than that to the H5N1-M2 channel, fully consistent with the recent report that the H1N1 swine virus was resistant to the two drugs. The findings and the relevant analysis reported here might provide useful structural insights for developing effective drugs against the new swine flu virus.

  14. Antigenic variation of H1N1, H1N2 and H3N2 swine influenza viruses in Japan and Vietnam.

    Science.gov (United States)

    Takemae, Nobuhiro; Nguyen, Tung; Ngo, Long Thanh; Hiromoto, Yasuaki; Uchida, Yuko; Pham, Vu Phong; Kageyama, Tsutomu; Kasuo, Shizuko; Shimada, Shinichi; Yamashita, Yasutaka; Goto, Kaoru; Kubo, Hideyuki; Le, Vu Tri; Van Vo, Hung; Do, Hoa Thi; Nguyen, Dang Hoang; Hayashi, Tsuyoshi; Matsuu, Aya; Saito, Takehiko

    2013-04-01

    The antigenicity of the influenza A virus hemagglutinin is responsible for vaccine efficacy in protecting pigs against swine influenza virus (SIV) infection. However, the antigenicity of SIV strains currently circulating in Japan and Vietnam has not been well characterized. We examined the antigenicity of classical H1 SIVs, pandemic A(H1N1)2009 (A(H1N1)pdm09) viruses, and seasonal human-lineage SIVs isolated in Japan and Vietnam. A hemagglutination inhibition (HI) assay was used to determine antigenic differences that differentiate the recent Japanese H1N2 and H3N2 SIVs from the H1N1 and H3N2 domestic vaccine strains. Minor antigenic variation between pig A(H1N1)pdm09 viruses was evident by HI assay using 13 mAbs raised against homologous virus. A Vietnamese H1N2 SIV, whose H1 gene originated from a human strain in the mid-2000s, reacted poorly with post-infection ferret serum against human vaccine strains from 2000-2010. These results provide useful information for selection of optimal strains for SIV vaccine production.

  15. Protection by Face Masks against H1N1 Virus on Trans-Pacific Passenger Aircraft, 2009

    Centers for Disease Control (CDC) Podcasts

    2013-07-10

    Dr. Mike Miller reads an abridged version of the Emerging Infectious Diseases’ article, Protection by Face Masks against H1N1 Virus on Trans-Pacific Passenger Aircraft, 2009.  Created: 7/10/2013 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/11/2013.

  16. Experiences after Twenty Months with Pandemic Influenza A (H1N1) 2009 Infection in the Naïve Norwegian Pig Population

    Science.gov (United States)

    Gjerset, B.; Er, C.; Løtvedt, S.; Jørgensen, A.; Hungnes, O.; Lium, B.; Germundsson, A.

    2011-01-01

    Pandemic (H1N1) 2009 influenza A virus was detected in Norwegian pigs in October 2009. Until then, Norway was regarded free of swine influenza. Intensified screening revealed 91 positive herds within three months. The virus was rapidly transmitted to the susceptible population, including closed breeding herds with high biosecurity. Humans were important for the introduction as well as spread of the virus to pigs. Mild or no clinical signs were observed in infected pigs. Surveillance of SIV in 2010 revealed that 41% of all the Norwegian pig herds had antibodies to pandemic (H1N1) 2009 virus. Furthermore, this surveillance indicated that pigs born in positive herds after the active phase did not seroconvert, suggesting no ongoing infection in the herds. However, results from surveillance in 2011 show a continuing spread of the infection in many herds, either caused by new introduction or by virus circulation since 2009. PMID:23074654

  17. Non-hydrolyzed in digestive tract and blood natural L-carnosine peptide ("bioactivated Jewish penicillin") as a panacea of tomorrow for various flu ailments: signaling activity attenuating nitric oxide (NO) production, cytostasis, and NO-dependent inhibition of influenza virus replication in macrophages in the human body infected with the virulent swine influenza A (H1N1) virus.

    Science.gov (United States)

    Babizhayev, Mark A; Deyev, Anatoliy I; Yegorov, Yegor E

    2013-01-01

    Influenza (flu) is caused by a highly contagious virus that is spread by coughs and sneezes. Flu symptoms include high fever, chills and sweating, sore throat, weakness, headache, muscle and joint pains, and cough. Older people and those with an underlying medical condition are more likely to develop serious complications, including secondary bacterial pneumonia, primary influenza pneumonia, and inflammation of the brain or heart. There are three types of flu virus: A, B, and C. The flu virus has a unique ability to change its surface structure. This allows it to escape recognition by the body's immune system and cause widespread illness (epidemics and pandemics). Most cases of influenza occur within a 6- to 8-week period during winter and spring. Epidemics occur when there are minor changes in the nature of the virus so that more people within a community are susceptible. Influenza A is more likely to cause epidemics. Pandemics (worldwide epidemics) occur when there are major changes in the virus so that the disease affects a large proportion of people in a geographic region or on more than one continent. The findings presented in this article have many important implications for understanding the influenza A (H1N1) viral pathogenesis, prevention, and treatment. Direct viral cytotoxicity (referred cytopathic effect) is only a fraction of several types of events induced by virus infection. Nitric oxide and oxygen free radicals such as superoxide anion (O2-·) are generated markedly in influenza A (including H1N1) virus-infected host boosts, and these molecular species are identified as the potent pathogenic agents. The mutual interaction of nitric oxide (NO) with O2-· resulting in the formation of peroxynitrite is operative in the pathogenic mechanism of influenza virus pneumonia. Influenza virus infection involves pathological events in which oxygen free radicals play an important role in the pathogenesis. The toxicity and reactivity of oxygen radicals generated

  18. Defining Moments in MMWR History: Swine Influenza A (H1N1) Infection in Two Children, Southern California, March-April 2009

    Centers for Disease Control (CDC) Podcasts

    2017-07-17

    In 2009, novel influenza A H1N1 virus infection in two children from southern California was first identified. This marked the beginning of the 2009 H1N1 influenza pandemic. MMWR was the first scientific publication to break the news of these cases and went on to publish critical findings from the pandemic. In this podcast, Dr. Dan Jernigan discusses this historic public health event.  Created: 7/17/2017 by MMWR.   Date Released: 7/17/2017.

  19. IN VITRO INTERACTION OF INFLUENZA VIRUS A(H1N1pdm09 WITH MONOCYTIC MACROPHAGES: INDIVIDUAL RESPONSES OF TLR7 AND RIG1 RECEPTOR GENES

    Directory of Open Access Journals (Sweden)

    T. M. Sokolova

    2017-01-01

    Full Text Available In vitro differentiation of donor blood monocytes to macrophages (Mph following GM-CSF treatment was accompanied by a significant increase in the levels of gene transcription signaling receptors TLR7 or RIG1. The levels of intracellular viral RNA (M1 gene in Mph remained high upon infection by influenza virus A H1N1pdm (Moscow 2009 for 24-96 hours. The innate immunity reactions caused by influenza virus show individual features: they are decreased in Mph from donor 1 which had initially high level of endosomal TLR7 gene activity, and it increased by influenza virus in MPh from donor 2 who had a very low level of TLR7 gene expression. The influenza H1N1pdm virus weakly stimulated expression of gene RIG1 and production of inflammatory cytokines in Mf in donor 1. The differences may be connected with individual sensitivity of the donors to influenza infection.

  20. A duplex real-time RT-PCR assay for detecting H5N1 avian influenza virus and pandemic H1N1 influenza virus

    Directory of Open Access Journals (Sweden)

    Qin E-de

    2010-06-01

    Full Text Available Abstract A duplex real-time reverse transcriptase polymerase chain reaction (RT-PCR assay was improved for simultaneous detection of highly pathogenic H5N1 avian influenza virus and pandemic H1N1 (2009 influenza virus, which is suitable for early diagnosis of influenza-like patients and for epidemiological surveillance. The sensitivity of this duplex real-time RT-PCR assay was 0.02 TCID50 (50% tissue culture infective dose for H5N1 and 0.2 TCID50 for the pandemic H1N1, which was the same as that of each single-target RT-PCR for pandemic H1N1 and even more sensitive for H5N1 with the same primers and probes. No cross reactivity of detecting other subtype influenza viruses or respiratory tract viruses was observed. Two hundred and thirty-six clinical specimens were tested by comparing with single real-time RT-PCR and result from the duplex assay was 100% consistent with the results of single real-time RT-PCR and sequence analysis.

  1. Design and performance of the CDC real-time reverse transcriptase PCR swine flu panel for detection of 2009 A (H1N1) pandemic influenza virus.

    Science.gov (United States)

    Shu, Bo; Wu, Kai-Hui; Emery, Shannon; Villanueva, Julie; Johnson, Roy; Guthrie, Erica; Berman, LaShondra; Warnes, Christine; Barnes, Nathelia; Klimov, Alexander; Lindstrom, Stephen

    2011-07-01

    Swine influenza viruses (SIV) have been shown to sporadically infect humans and are infrequently identified by the Influenza Division of the Centers for Disease Control and Prevention (CDC) after being received as unsubtypeable influenza A virus samples. Real-time reverse transcriptase PCR (rRT-PCR) procedures for detection and characterization of North American lineage (N. Am) SIV were developed and implemented at CDC for rapid identification of specimens from cases of suspected infections with SIV. These procedures were utilized in April 2009 for detection of human cases of 2009 A (H1N1) pandemic (pdm) influenza virus infection. Based on genetic sequence data derived from the first two viruses investigated, the previously developed rRT-PCR procedures were optimized to create the CDC rRT-PCR Swine Flu Panel for detection of the 2009 A (H1N1) pdm influenza virus. The analytical sensitivity of the CDC rRT-PCR Swine Flu Panel was shown to be 5 copies of RNA per reaction and 10(-1.3 - -0.7) 50% infectious doses (ID(50)) per reaction for cultured viruses. Cross-reactivity was not observed when testing human clinical specimens or cultured viruses that were positive for human seasonal A (H1N1, H3N2) and B influenza viruses. The CDC rRT-PCR Swine Flu Panel was distributed to public health laboratories in the United States and internationally from April 2009 until June 2010. The CDC rRT-PCR Swine Flu Panel served as an effective tool for timely and specific detection of 2009 A (H1N1) pdm influenza viruses and facilitated subsequent public health response implementation.

  2. Probable transmisión vertical del virus de la influenza A (H1N1: a propósito de un caso Probable vertical transmission of the influenza virus A (H1N1: apropos of a case

    Directory of Open Access Journals (Sweden)

    Rubén D. Vásquez

    2010-09-01

    Full Text Available Se reporta el caso de un recién nacido varón, producto de embarazo de 36 semanas, con diagnóstico de neumonía congénita y examen confirmatorio de infección por el virus de la influenza A (H1N1, sin ningún otro tipo de contacto sospechoso. La madre ingresó al hospital con insuficiencia respiratoria y antecedente de proceso gripal de cinco días de evolución, durante los primeros días de la pandemia en el Perú. Por la evolución grave del proceso respiratorio, se le administró ventilación mecánica para luego ser sometida a cesárea por sufrimiento fetal agudo y oligoamnios. Se confirmó en la madre infección por el virus de la influenza A H1N1 epidémico y tuberculosis pulmonar.We report the case of a male newborn, product of a 36 week pregnancy, with diagnosis of congenital pneumonia and with a confirmatory test for influenza A (H1N1 virus, without any other suspicious contact. The mother was admitted to the hospital with respiratory failure and the history of a flu-like episode of 5 days of evolution, during the first days of the pandemic in Peru. Due to the severe evolution of the respiratory process, assisted ventilation was given to her and then a cesarean section was performed due to acute fetal distress and oligoamnios. The mother was later confirmed as a case of epidemic influenza A (H1N1 and pulmonary tuberculosis.

  3. [Pandemic influenza A (H1N1 virus) on Futuna Island in the Pacific, from August to September 2009].

    Science.gov (United States)

    Chenaitia, Hichem; Massa, Horace; Garry, Philippe; Puget, André; Yvon, Jean-Francois; Dutaut, Elisabeth; Bessereau, Jacques; Michelet, Pierre; Auffray, Jean-Pierre; Delmont, Jean

    2011-03-01

    The aim of this study is to report the observation of the pandemic of influenza A (H1N1 virus) from August to September 2009 on the island of Futuna, in a context of isolated island that may mimic an environment closed. We conducted a prospective observational study of influenza-like illness, from the first confirmed case of influenza A on the island until the end of the epidemic wave. From August 15 to September 20, 2009, 1536 cases of influenza syndrome were identified. The estimate of the overall clinical attack rate was 36 %. The evolution of the epidemic shows an explosion of new cases of influenza A and subsequently a rapid decline of the epidemic. The spread of the infection was made by contiguity, jumping from one city to another. The cumulative number of cases by age group shows that the majority of cases were children and young adults under the age of 20 years. The most frequent symptoms were cough, rhinorrhea, headache, myalgia or asthenia, and fever. This study, despite these limitations, shows an explosive epidemic of influenza A, which can be explained by the circulation of virus that has been fostered by gatherings of public and closed environment. Age group classification shows that majority of cases were young, in contrast to seasonal influenza, but the symptoms were alike. This study highlights the difficulties to manage an epidemic surveillance system at high level and given the quick spread of the disease. Copyright © 2010. Published by Elsevier Masson SAS.

  4. Transmission dynamics of pandemic influenza A(H1N1)pdm09 virus in humans and swine in backyard farms in Tumbes, Peru.

    Science.gov (United States)

    Tinoco, Yeny O; Montgomery, Joel M; Kasper, Mathew R; Nelson, Martha I; Razuri, Hugo; Guezala, Maria C; Azziz-Baumgartner, Eduardo; Widdowson, Marc-Alain; Barnes, John; Gilman, Robert H; Bausch, Daniel G; Gonzalez, Armando E

    2016-01-01

    We aimed to determine the frequency of pH1N1 transmission between humans and swine on backyard farms in Tumbes, Peru. Two-year serial cross-sectional study comprising four sampling periods: March 2009 (pre-pandemic), October 2009 (peak of the pandemic in Peru), April 2010 (1st post-pandemic period), and October 2011 (2nd post-pandemic period). Backyard swine serum, tracheal swabs, and lung sample were collected during each sampling period. We assessed current and past pH1N1 infection in swine through serological testing, virus culture, and RT-PCR and compared the results with human incidence data from a population-based active surveillance cohort study in Peru. Among 1303 swine sampled, the antibody prevalence to pH1N1 was 0% pre-pandemic, 8% at the peak of the human pandemic (October 2009), and 24% in April 2010 and 1% in October 2011 (post-pandemic sampling periods). Trends in swine seropositivity paralleled those seen in humans in Tumbes. The pH1N1 virus was isolated from three pigs during the peak of the pandemic. Phylogenetic analysis revealed that these viruses likely represent two separate human-to-swine transmission events in backyard farm settings. Our findings suggest that human-to-swine pH1N1 transmission occurred during the pandemic among backyard farms in Peru, emphasizing the importance of interspecies transmission in backyard pig populations. Continued surveillance for influenza viruses in backyard farms is warranted. © 2015 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  5. Analysis of host responses and fitness in different pandemic H1N1 (2009) influenza virus in mice and ferrets

    OpenAIRE

    Martínez Orellana, Pamela Analía

    2014-01-01

    La gripe es un problema de salud pública en todo el mundo, siendo una de las enfermedades infecciosas más comunes y una patología de las vías aéreas altamente contagiosa. Desde abril de 2009, un nuevo virus de influenza A H1N1, con origen porcino dio lugar a la aparición de brotes en todo el mundo siendo declarada posteriormente como una situación de pandemia. Hoy en día el virus pdmH1N1 de 2009 continúa en circulación, generalmente provocando infecciones leves y autolimitadas. Sin embargo, u...

  6. Reassortant swine influenza viruses isolated in Japan contain genes from pandemic A(H1N1) 2009.

    Science.gov (United States)

    Kanehira, Katsushi; Takemae, Nobuhiro; Uchida, Yuko; Hikono, Hirokazu; Saito, Takehiko

    2014-06-01

    In 2013, three reassortant swine influenza viruses (SIVs)-two H1N2 and one H3N2-were isolated from symptomatic pigs in Japan; each contained genes from the pandemic A(H1N1) 2009 virus and endemic SIVs. Phylogenetic analysis revealed that the two H1N2 viruses, A/swine/Gunma/1/2013 and A/swine/Ibaraki/1/2013, were reassortants that contain genes from the following three distinct lineages: (i) H1 and nucleoprotein (NP) genes derived from a classical swine H1 HA lineage uniquely circulating among Japanese SIVs; (ii) neuraminidase (NA) genes from human-like H1N2 swine viruses; and (iii) other genes from pandemic A(H1N1) 2009 viruses. The H3N2 virus, A/swine/Miyazaki/2/2013, comprised genes from two sources: (i) hemagglutinin (HA) and NA genes derived from human and human-like H3N2 swine viruses and (ii) other genes from pandemic A(H1N1) 2009 viruses. Phylogenetic analysis also indicated that each of the reassortants may have arisen independently in Japanese pigs. A/swine/Miyazaki/2/2013 were found to have strong antigenic reactivities with antisera generated for some seasonal human-lineage viruses isolated during or before 2003, whereas A/swine/Miyazaki/2/2013 reactivities with antisera against viruses isolated after 2004 were clearly weaker. In addition, antisera against some strains of seasonal human-lineage H1 viruses did not react with either A/swine/Gunma/1/2013 or A/swine/Ibaraki/1/2013. These findings indicate that emergence and spread of these reassortant SIVs is a potential public health risk. © 2014 The Societies and Wiley Publishing Asia Pty Ltd.

  7. Swine-origin influenza A viral (H1N1) infection in children. Chest computed tomography findings

    International Nuclear Information System (INIS)

    Im, Soo-Ah; Kim, Hyo-Lim; Yoon, Jong-seo; Kang, Jin-Han; Lee, Joon-Sung; Chun, Ho-Jong

    2011-01-01

    The aim of this study was to review the chest computed tomography (CT) findings in children with swine-origin influenza (H1N1) virus (S-OIV) infection. The radiologists retrospectively reviewed chest CT findings in 12 children with S-OIV infection and recorded the following findings: ground-glass opacities (GGO), consolidation, nodules, reticular opacities, peribronchial cuffing, and air trapping; distribution; affected lobes. The presence of pleural effusions, pneumomediastinum, pulmonary interstitial emphysema (PIE), and lymphadenopathy was also recorded. Chest CT revealed GGO (67%), consolidation (67%), nodules (25%), peribronchial cuffing (42%), and air trapping (33%). The distribution of the lesions was random (75%), peribronchial (17%), or subpleural (8%). The lobes affected were the lower (92%), upper (58%), and middle (17%) lobes. There were associated pleural effusions (42%), PIE (42%), pneumomediastinum (33%), and lymphadenopathy (75%). Among five patients with air-leak complications, three had a history of allergies and three required the intensive care unit. Chest CT findings in children with S-OIV infection were peribronchial thickening and a mixture of airspace consolidation and GGO with random distribution and lower lobe predominance. Pleural effusion, lymphadenopathy, PIE, and pneumomediastinum may be associated findings. (author)

  8. Influenza H5N1 and H1N1 virus replication and innate immune responses in bronchial epithelial cells are influenced by the state of differentiation.

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    Renee W Y Chan

    Full Text Available Influenza H5N1 virus continues to be enzootic in poultry and transmits zoonotically to humans. Although a swine-origin H1N1 virus has emerged to become pandemic, its virulence for humans remains modest in comparison to that seen in zoonotic H5N1 disease. As human respiratory epithelium is the primary target cells for influenza viruses, elucidating the viral tropism and host innate immune responses of influenza H5N1 virus in human bronchial epithelium may help to understand the pathogenesis. Here we established primary culture of undifferentiated and well differentiated normal human bronchial epithelial (NHBE cells and infected with highly pathogenic influenza H5N1 virus (A/Vietnam/3046/2004 and a seasonal influenza H1N1 virus (A/Hong Kong/54/1998, the viral replication kinetics and cytokine and chemokine responses were compared by qPCR and ELISA. We found that the in vitro culture of the well differentiated NHBE cells acquired the physiological properties of normal human bronchi tissue which express high level of alpha2-6-linked sialic acid receptors and human airway trypsin-like (HAT protease, in contrast to the low expression in the non-differentiated NHBE cells. When compared to H1N1 virus, the H5N1 virus replicated more efficiently and induced a stronger type I interferon response in the undifferentiated NHBE cells. In contrast, in well differentiated cultures, H5N1 virus replication was less efficient and elicited a lower interferon-beta response in comparison with H1N1 virus. Our data suggest that the differentiation of bronchial epithelial cells has a major influence in cells' permissiveness to human H1N1 and avian H5N1 viruses and the host innate immune responses. The reduced virus replication efficiency partially accounts for the lower interferon-beta responses in influenza H5N1 virus infected well differentiated NHBE cells. Since influenza infection in the bronchial epithelium will lead to tissue damage and associate with the

  9. Characteristics and outcome of critically ill patients with 2009 H1N1 influenza infection in Syria

    Science.gov (United States)

    Alsadat, Reem; Dakak, Abdulrahman; Mazlooms, Mouna; Ghadhban, Ghasan; Fattoom, Shadi; Betelmal, Ibrahim; Abouchala, Nabil; Kherallah, Mazen

    2012-01-01

    Objectives: To describe the epidemiologic characteristics, clinical features, and outcome of severe cases of 2009 H1N1 influenza A infections who were admitted to the intensive care units (ICUs) in Damascus, Syria. Materials and Methods: Retrospectively, we collected clinical data on all patients who were admitted to the ICU with confirmed or suspected diagnosis of severe 2009 H1N1 influenza A with respiratory failure at 4 major tertiary care hospitals in Damascus, Syria. Acute Physiology and Chronic Health Evaluation (APACHE) II system was used to assess the severity of illness within the first 24 h after admission. The outcome was overall hospital mortality. Results: Eighty patients were admitted to the ICU with severe 2009 H1N1 infection. The mean age was 40.7 years; 69.8% of patients had ≥1 of the risk factors: asthmatics 20%, obesity 23.8%, and pregnancy 5%; and 72.5% had acute lung injury or adult respiratory distress syndrome, 12.5% had viral pneumonia, 42.5% had secondary bacterial pneumonia, and 15% had exacerbation of airflow disease. Mechanical ventilation was required in 73.7% of cases. The mean hospital length of stay was 11.7 days (median 8 days, range 0–77 days, IQR: 5–14 days). The overall mortality rate was 51% for a mean APACHE II score of 15.2 with a predicted mortality of 21% (standardized mortality ratio of 2.4, 95% confidence interval: 1.7–3.2, P value < 0.001). Conclusion: Critically ill patients with severe 2009 H1N1 infection in this limited resource country had a much higher mortality rate than the predicted APACHE II mortality rate or when compared with the reported mortality rates for severe cases in other countries during 2009 H1N1 pandemic. PMID:23210019

  10. High burden of non-influenza viruses in influenza-like illness in the early weeks of H1N1v epidemic in France.

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    Nathalie Schnepf

    Full Text Available BACKGROUND: Influenza-like illness (ILI may be caused by a variety of pathogens. Clinical observations are of little help to recognise myxovirus infection and implement appropriate prevention measures. The limited use of molecular tools underestimates the role of other common pathogens. OBJECTIVES: During the early weeks of the 2009-2010 flu pandemic, a clinical and virological survey was conducted in adult and paediatric patients with ILI referred to two French University hospitals in Paris and Tours. Aims were to investigate the different pathogens involved in ILI and describe the associated symptoms. METHODS: H1N1v pandemic influenza diagnosis was performed with real time RT-PCR assay. Other viral aetiologies were investigated by the molecular multiplex assay RespiFinder19®. Clinical data were collected prospectively by physicians using a standard questionnaire. RESULTS: From week 35 to 44, endonasal swabs were collected in 413 patients. Overall, 68 samples (16.5% were positive for H1N1v. In 13 of them, other respiratory pathogens were also detected. Among H1N1v negative samples, 213 (61.9% were positive for various respiratory agents, 190 in single infections and 23 in mixed infections. The most prevalent viruses in H1N1v negative single infections were rhinovirus (62.6%, followed by parainfluenza viruses (24.2% and adenovirus (5.3%. 70.6% of H1N1v cases were identified in patients under 40 years and none after 65 years. There was no difference between clinical symptoms observed in patients infected with H1N1v or with other pathogens. CONCLUSION: Our results highlight the high frequency of non-influenza viruses involved in ILI during the pre-epidemic period of a flu alert and the lack of specific clinical signs associated with influenza infections. Rapid diagnostic screening of a large panel of respiratory pathogens may be critical to define and survey the epidemic situation and to provide critical information for patient management.

  11. Prophylactic and therapeutic efficacy of avian antibodies against influenza virus H5N1 and H1N1 in mice.

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    Huan H Nguyen

    Full Text Available BACKGROUND: Pandemic influenza poses a serious threat to global health and the world economy. While vaccines are currently under development, passive immunization could offer an alternative strategy to prevent and treat influenza virus infection. Attempts to develop monoclonal antibodies (mAbs have been made. However, passive immunization based on mAbs may require a cocktail of mAbs with broader specificity in order to provide full protection since mAbs are generally specific for single epitopes. Chicken immunoglobulins (IgY found in egg yolk have been used mainly for treatment of infectious diseases of the gastrointestinal tract. Because the recent epidemic of highly pathogenic avian influenza virus (HPAIV strain H5N1 has resulted in serious economic losses to the poultry industry, many countries including Vietnam have introduced mass vaccination of poultry with H5N1 virus vaccines. We reasoned that IgY from consumable eggs available in supermarkets in Vietnam could provide protection against infections with HPAIV H5N1. METHODS AND FINDINGS: We found that H5N1-specific IgY that are prepared from eggs available in supermarkets in Vietnam by a rapid and simple water dilution method cross-protect against infections with HPAIV H5N1 and related H5N2 strains in mice. When administered intranasally before or after lethal infection, the IgY prevent the infection or significantly reduce viral replication resulting in complete recovery from the disease, respectively. We further generated H1N1 virus-specific IgY by immunization of hens with inactivated H1N1 A/PR/8/34 as a model virus for the current pandemic H1N1/09 and found that such H1N1-specific IgY protect mice from lethal influenza virus infection. CONCLUSIONS: The findings suggest that readily available H5N1-specific IgY offer an enormous source of valuable biological material to combat a potential H5N1 pandemic. In addition, our study provides a proof-of-concept for the approach using virus

  12. H1N1 influenza viruses varying widely in hemagglutinin stability transmit efficiently from swine to swine and to ferrets.

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    Marion Russier

    2017-03-01

    Full Text Available A pandemic-capable influenza virus requires a hemagglutinin (HA surface glycoprotein that is immunologically unseen by most people and is capable of supporting replication and transmission in humans. HA stabilization has been linked to 2009 pH1N1 pandemic potential in humans and H5N1 airborne transmissibility in the ferret model. Swine have served as an intermediate host for zoonotic influenza viruses, yet the evolutionary pressure exerted by this host on HA stability was unknown. For over 70 contemporary swine H1 and H3 isolates, we measured HA activation pH to range from pH 5.1 to 5.9 for H1 viruses and pH 5.3 to 5.8 for H3 viruses. Thus, contemporary swine isolates vary widely in HA stability, having values favored by both avian (pH >5.5 and human and ferret (pH ≤5.5 species. Using an early 2009 pandemic H1N1 (pH1N1 virus backbone, we generated three viruses differing by one HA residue that only altered HA stability: WT (pH 5.5, HA1-Y17H (pH 6.0, and HA2-R106K (pH 5.3. All three replicated in pigs and transmitted from pig-to-pig and pig-to-ferret. WT and R106 viruses maintained HA genotype and phenotype after transmission. Y17H (pH 6.0 acquired HA mutations that stabilized the HA protein to pH 5.8 after transmission to pigs and 5.5 after transmission to ferrets. Overall, we found swine support a broad range of HA activation pH for contact transmission and many recent swine H1N1 and H3N2 isolates have stabilized (human-like HA proteins. This constitutes a heightened pandemic risk and underscores the importance of ongoing surveillance and control efforts for swine viruses.

  13. 2009 Pandemic Influenza A Virus Subtype H1N1 in Morocco, 2009–2010: Epidemiology, Transmissibility, and Factors Associated With Fatal Cases

    Science.gov (United States)

    Barakat, Amal; Ihazmad, Hassan; El Falaki, Fatima; Tempia, Stefano; Cherkaoui, Imad; El Aouad, Rajae

    2012-01-01

    Background. Following the emergence of 2009 pandemic influenza A virus subtype H1N1 (A[H1N1]pdm09) in the United States and Mexico in April 2009, A(H1N1)pdm09 spread rapidly all over the world. There is a dearth of information about the epidemiology of A(H1N1)pdm09 in Africa, including Morocco. We describe the epidemiologic characteristics of the A(H1N1)pdm09 epidemic in Morocco during 2009–2010, including transmissibility and risk factors associated with fatal disease. Methods. We implemented influenza surveillance for patients presenting with influenza-like illness (ILI) at 136 private and public clinics for patients with severe acute respiratory illness (SARI) at 16 regional public hospitals from June 2009 through February 2010. Respiratory samples and structured questionnaires were collected from all enrolled patients, and samples were tested by real-time reverse-transcription polymerase chain reaction for influenza viruses. We estimated the risk factors associated with fatal disease as well as the basic reproduction number (R0) and the serial interval of the pandemic virus. Results. From June 2009 through February 2010, we obtained 3937 specimens, of which 1452 tested positive for influenza virus. Of these, 1398 (96%) were A(H1N1)pdm09. Forty percent of specimens from ILI cases (1056 of 2646) and 27% from SARI cases (342 of 1291) were positive for A(H1N1)pdm09. Sixty-four deaths occurred among laboratory-confirmed A(H1N1)pdm09 SARI cases. Among these cases, those who had hypertension (age-adjusted odd ratio [aOR], 28.2; 95% confidence interval [CI], 2.0–398.7), had neurological disorders (aOR, 7.5; 95% CI, 1.5–36.4), or were obese (aOR, 7.1; 95% CI, 1.6–31.1), as well as women of gestational age who were pregnant (aOR, 2.5; 95% CI, 1.1–5.6), were at increased risk of death. Across the country, elevated numbers of locally acquired infections were detected 4 months after the detection of the first laboratory-confirmed case and coincided with the

  14. Severe Pneumonia Caused by Influenza A (H1N1 Virus Successfully Managed with Extracorporeal Life Support in a Comorbid Former Preterm Infant

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    Genny Raffaeli

    2017-03-01

    Full Text Available Influenza A (H1N1 virus infection is a global health burden, leading to significant pediatric morbidity and mortality. Prematurity, young age and comorbidities are important risk factors for unfavorable outcomes. Preventive strategies, such as healthcare workers and household contacts vaccination as well as the implementation of infection control practices during the epidemic season, are crucial to protect the most vulnerable populations. Early diagnosis, timely administration of antiviral drugs and supportive therapy are crucial to lead to a complete recovery. When conventional treatment fails, extracorporeal life support (ECLS may be employed. In neonates and young infants, this high-tech support is burdened by specific technical complexity. Despite the potential risks related to this aggressive approach, ECLS is a life-saving procedure in 65% of pediatric viral pneumonia and in 73% of sepsis cases. Here, we report the successful outcome of a 51-day formerly preterm infant, suffering from a surgical necrotizing enterocolitis (NEC, complicated with hospital-acquired pneumonia due to influenza A (H1N1 virus. She developed a severe respiratory failure, unresponsive to conventional therapy, and successfully treated with ECLS. To our knowledge, this is the first report on the use of ECLS in a formerly preterm infant, suffering from NEC complicated by influenza A (H1N1 virus infection.

  15. Identification of swine H1N2/pandemic H1N1 reassortant influenza virus in pigs, United States.

    Science.gov (United States)

    Ali, Ahmed; Khatri, Mahesh; Wang, Leyi; Saif, Yehia M; Lee, Chang-Won

    2012-07-06

    In October and November 2010, novel H1N2 reassortant influenza viruses were identified from pigs showing mild respiratory signs that included cough and depression. Sequence and phylogenetic analysis showed that the novel H1N2 reassortants possesses HA and NA genes derived from recent H1N2 swine isolates similar to those isolated from Midwest. Compared to the majority of reported reassortants, both viruses preserved human-like host restrictive and putative antigenic sites in their HA and NA genes. The four internal genes, PB2, PB1, PA, and NS were similar to the contemporary swine triple reassortant viruses' internal genes (TRIG). Interestingly, NP and M genes of the novel reassortants were derived from the 2009 pandemic H1N1. The NP and M proteins of the two isolates demonstrated one (E16G) and four (G34A, D53E, I109T, and V313I) amino acid changes in the M2 and NP proteins, respectively. Similar amino acid changes were also noticed upon incorporation of the 2009 pandemic H1N1 NP in other reassortant viruses reported in the U.S. Thus the role of those amino acids in relation to host adaptation need to be further investigated. The reassortments of pandemic H1N1 with swine influenza viruses and the potential of interspecies transmission of these reassortants from swine to other species including human indicate the importance of systematic surveillance of swine population to determine the origin, the prevalence of similar reassortants in the U.S. and their impact on both swine production and public health. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. INFECCIÓN POR VIRUS DE LA GRIPE A H1N1NV EN ELCOMPLEJO ASISTENCIAL UNIVERSITARIO DE BURGOSDESDE DICIEMBRE DE 2010 A MARZO DE 2011

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    Megías Lobón G

    2012-01-01

    Full Text Available SUMMARY: INFLUENZA A H1N1NV INFECTION IN A BURGOS HOSPITAL FROM DECEMBER 2010 TO MARCH 2011 Introduction: Monitoring and characterization of infection with pandemic (H1N1nv 2009 is an essential part of monitoring the evolution, epidemiology and severity of a pandemic. The aim of this paper is to describe and analyze the clinical characteristics and risk factors of patients admitted to our hospital the 2010-2011 season. Methods: Detection of influenza A H1N1nv virus in 266 respiratory specimens (242 patients with suspected infection and descriptive and comparative analysis of data collected from each patient: age, sex, service, reason for admission, risk factors and treatment with antivirals. Results: The most common reason for admission (52.47% was the presence of clinical respiratory signs. 69.4% of patients had risk factors, with chronic respiratory disease (CRD, the most frequent (20.2%. 14.2% were pediatric patients. The infection of Influenza A H1N1nv was confirmed in 26,4% of patients. The mean age among the infected patients was 36 years versus 44.85 years in non-infected. This difference was statistically significant (p = 0.011. 75% of infected patients had risk factors. Of these, 68.7% had CRD only factor being predominant. 6% of patients with infection were vaccinated. Conclusion: The positivity rate was similar to that observed in the previous season. There was a greater involvement among young-adult population. The CRD is the most common risk factor. Vaccine coverage was low.

  17. H1N1 influenza (Swine flu)

    Science.gov (United States)

    Swine flu; H1N1 type A influenza ... The H1N1 virus is now considered a regular flu virus. It is one of the three viruses included in the regular (seasonal) flu vaccine . You cannot get H1N1 flu virus from ...

  18. Inhibitory effects and related molecular mechanisms of total flavonoids in Mosla chinensis Maxim against H1N1 influenza virus.

    Science.gov (United States)

    Zhang, Xiao-Xia; Wu, Qiao-Feng; Yan, Yun-Liang; Zhang, Feng-Ling

    2018-02-01

    The Shixiangru (Mosla chinensis Maxim) total flavonoids (STF) mainly contain luteolin and apigenin. The study aims to examine the inhibitory effects of STF on anti-H1N1 influenza virus and its related molecular mechanisms in pneumonia mice. The viral pneumonia mice were treated with Ribavirin or various doses of STF. We observed histological changes of lung by immunohistochemistry and measured lung index to value anti-influenza virus effects of STF. The concentrations of inflammatory cytokines and anti-oxidant factors were detected by ELISA. RT-PCR and western blot assays were used to determine the expression level of TLR pathway's key genes and proteins in lung tissues. We found that the pathological changes of lung in the viral pneumonia mice obviously alleviated by STF treatments and the STF (288 or 576 mg/kg) could significantly decrease lung indices. Moreover, the up-regulation (IL-6, TNF-α, IFN-γ, and NO) and down-regulation (IL-2, SOD and GSH) of inflammatory cytokines and anti-oxidant factors were associated with higher clearance of virus and reduction of inflammatory lung tissue damage. Meanwhile, the expression levels of TLR3, TLR7, MyD88, TRAF3 and NF-κB p65 of the TLR pathway were reduced by STF treatment. This study suggested that STF may be a promising candidate for treating H1N1 influenza and subsequent viral pneumonia.

  19. Don't let the flu catch you: agency assignment in printed educational materials about the H1N1 influenza virus.

    Science.gov (United States)

    McGlone, Matthew S; Bell, Robert A; Zaitchik, Sarah T; McGlynn, Joseph

    2013-01-01

    In English and in other languages, the agency for viral transmission can be grammatically assigned to people (e.g., Thousands may contract H1N1) or to the virus itself (e.g., H1N1 may infect thousands). These assignment options shape different conceptions of transmission as attributable either to social contact within one's control or to pursuit of an active predator. The authors tested the effect of agency assignment and agentic images on young adults' (N = 246) reactions to educational materials about H1N1 influenza. The authors hypothesized that assigning agency to the virus would heighten perceived severity and personal susceptibility relative to human agency assignment. Results were consistent with this hypothesis, indicating that virus agency increased perceptions of severity, personal susceptibility, and reported intentions to seek vaccination relative to human agency. The image manipulation did not directly affect these factors. The findings suggest that strategic agency assignment can improve the effectiveness of educational materials about influenza and other health threats.

  20. Point of care strategy for rapid diagnosis of novel A/H1N1 influenza virus.

    Directory of Open Access Journals (Sweden)

    Antoine Nougairede

    Full Text Available Within months of the emergence of the novel A/H1N1 pandemic influenza virus (nA/H1N1v, systematic screening for the surveillance of the pandemic was abandoned in France and in some other countries. At the end of June 2009, we implemented, for the public hospitals of Marseille, a Point Of Care (POC strategy for rapid diagnosis of the novel A/H1N1 influenza virus, in order to maintain local surveillance and to evaluate locally the kinetics of the pandemic.Two POC laboratories, located in strategic places, were organized to receive and test samples 24 h/24. POC strategy consisted of receiving and processing naso-pharyngeal specimens in preparation for the rapid influenza diagnostic test (RIDT and real-time RT-PCR assay (rtRT-PCR. This strategy had the theoretical capacity of processing up to 36 samples per 24 h. When the flow of samples was too high, the rtRT-PCR test was abandoned in the POC laboratories and transferred to the core virology laboratory. Confirmatory diagnosis was performed in the core virology laboratory twice a day using two distinct rtRT-PCR techniques that detect either influenza A virus or nA/N1N1v. Over a period of three months, 1974 samples were received in the POC laboratories, of which 111 were positive for nA/H1N1v. Specificity and sensitivity of RIDT were 100%, and 57.7% respectively. Positive results obtained using RIDT were transmitted to clinical practitioners in less than 2 hours. POC processed rtRT-PCR results were available within 7 hours, and rtRT-PCR confirmation within 24 hours.The POC strategy is of benefit, in all cases (with or without rtRT-PCR assay, because it provides continuous reception/processing of samples and reduction of the time to provide consolidated results to the clinical practitioners. We believe that implementation of the POC strategy for the largest number of suspect cases may improve the quality of patient care and our knowledge of the epidemiology of the pandemic.

  1. H1N1 Swine Influenza Viruses Differ from Avian Precursors by a Higher pH Optimum of Membrane Fusion.

    Science.gov (United States)

    Baumann, Jan; Kouassi, Nancy Mounogou; Foni, Emanuela; Klenk, Hans-Dieter; Matrosovich, Mikhail

    2016-02-01

    The H1N1 Eurasian avian-like swine (EAsw) influenza viruses originated from an avian H1N1 virus. To characterize potential changes in the membrane fusion activity of the hemagglutinin (HA) during avian-to-swine adaptation of the virus, we studied EAsw viruses isolated in the first years of their circulation in pigs and closely related contemporary H1N1 viruses of wild aquatic birds. Compared to the avian viruses, the swine viruses were less sensitive to neutralization by lysosomotropic agent NH4Cl in MDCK cells, had a higher pH optimum of hemolytic activity, and were less stable at acidic pH. Eight amino acid substitutions in the HA were found to separate the EAsw viruses from their putative avian precursor; four substitutions-T492S, N722D, R752K, and S1132F-were located in the structural regions of the HA2 subunit known to play a role in acid-induced conformational transition of the HA. We also studied low-pH-induced syncytium formation by cell-expressed HA proteins and found that the HAs of the 1918, 1957, 1968, and 2009 pandemic viruses required a lower pH for fusion induction than did the HA of a representative EAsw virus. Our data show that transmission of an avian H1N1 virus to pigs was accompanied by changes in conformational stability and fusion promotion activity of the HA. We conclude that distinctive host-determined fusion characteristics of the HA may represent a barrier for avian-to-swine and swine-to-human transmission of influenza viruses. Continuing cases of human infections with zoonotic influenza viruses highlight the necessity to understand which viral properties contribute to interspecies transmission. Efficient binding of the HA to cellular receptors in a new host species is known to be essential for the transmission. Less is known about required adaptive changes in the membrane fusion activity of the HA. Here we show that adaptation of an avian influenza virus to pigs in Europe in 1980s was accompanied by mutations in the HA, which decreased

  2. The prevalence of enteroviruses that cause respiratory infections in patients with influenzavirus A/H1N1 hospitalized in the Lublin province

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    Jarzynski Adrian

    2014-09-01

    Full Text Available Viruses that cause respiratory tract infections are the most common agents of infectious diseases in humans throughout the world. A virus that infects the respiratory system, may induce various clinical symptoms. What is more, the same symptoms may be caused by different viruses. The aim of the study was to analyze the prevalence of enteroviruses that cause respiratory infections in patients with influenzavirus A/H1N1 hospitalized in the Lublin province. The experimental material was throat and nose swabs taken from patients hospitalized in Lublin and Tomaszow Lubelski. In the group of 44 patients (20 women and 24 men infected with influenza A/H1N1, the genetic material of enteroviruses was detected in 13 patients (29.5%. Respiratory viruses co-infections are very common in hospitalized patients. Studies show that co-infection with influenza virus and enterovirus are more common in children than in adults. Moreover, viral respiratory tract infections are independent from the patients’ gender.

  3. Febrile neutropenia due to H1N1 infection: Rare entity

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    Ayberk A. Besen

    2016-01-01

    Conclusion: Influenza infection is an important etiological agent in immunocompromised hosts, namely neutropenic patients, which cause significant morbidity and mortality. Viral etiology and antiviral treatment should also be considered in suspected patients especially during epidemics and pandemics.

  4. Pandemic influenza A (H1N1)

    African Journals Online (AJOL)

    ... in Port Shepstone, South Africa. Introduction. Influenza A (H1N1) 2009 'swine flu' variant is currently a global pandemic.1 The infection associated with this virus is usually a mild, self-limiting illness. However, it may progress to severe pneumonia requiring intensive care unit (ICU) therapy in 31% of patients.2 This may.

  5. Surveillance of hospitalizations with pandemic A(H1N1 2009 influenza infection in Queensland, Australia

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    Frances Birrell

    2011-05-01

    Full Text Available Objective : To describe the demographic and clinical characteristics of patients hospitalized with pandemic A(H1N1 2009 infection in Queensland, Australia between 25 May and 3 October 2009 and to examine the relationship between timing of antiviral treatment and severity of illness.Method: Using data from the Queensland Health EpiLog information system, descriptive analysis and logistic regression modelling were used to describe and model factors which influence patient outcomes (death, admission to intensive care unit and/or special care unit. Data on patients admitted to hospital in Queensland with confirmed pandemic A(H1N1 2009 infection were included in this analysis.Results: 1236 patients with pandemic A(H1N1 2009 infection were admitted to hospitals in Queensland during the study period. Of the total group: 15% were admitted to an intensive care unit or special care unit; 3% died; 34% were under the age of 18 years and 8% were 65 years of age or older; and 55% had at least one underlying medical condition. Among the 842 patients for whom data were available regarding the use of antiviral drugs, antiviral treatment was initiated in 737 (87.5% patients with treatment commencing at a median of one day (range 1–33 days after onset of illness. Admission to an intensive care unit or special care unit (ICU/SCU or death was significantly associated with increased age, lack of timeliness of antiviral treatment, chronic renal disease and morbid obesity.Discussion: Early antiviral treatment was significantly associated with lower likelihood of ICU/SCU admission or death. Early antiviral treatment for influenza cases may therefore have important public health implications.

  6. Clinical and microbiological evaluation of travel-associated respiratory tract infections in travelers returning from countries affected by pandemic A(H1N1) 2009 influenza.

    Science.gov (United States)

    Jauréguiberry, Stéphane; Boutolleau, David; Grandsire, Eric; Kofman, Tomek; Deback, Claire; Aït-Arkoub, Zaïna; Bricaire, François; Agut, Henri; Caumes, Eric

    2012-01-01

    Although acute respiratory tract infections (RTI) have been recognized as a significant cause of illness in returning travelers, few studies have specifically evaluated the etiologies of RTI in this population. This prospective investigation evaluated travelers returning from countries with endemic influenza A(H1N1) 2009, and who were seen in our department at the onset of the outbreak (April-July 2009). Patients were included if they presented with signs of RTI that occurred during travel or less than 7 days after return from overseas travel. Patients were evaluated for microbial agents with RespiFinder plus assay, and throat culture according to clinical presentation. A total of 113 travelers (M/F ratio 1.2:1; mean age 39 y) were included. They were mainly tourists (n = 50; 44.2%) mostly returning from North America (n = 65; 58%) and Mexico (n = 21; 18.5%). The median duration of travel was 23 days (range 2-540 d). The median lag time between return and onset of illness was 0.2 days (range 10 d prior to 7 d after). The main clinical presentation of RTI was influenza-like illness (n = 76; 67.3%). Among the 99 microbiologically evaluated patients, a pathogen was found by polymerase chain reaction (PCR) or throat culture in 65 patients (65.6%). The main etiological agents were influenza A(H1N1) 2009 (18%), influenza viruses (14%), and rhinovirus (20%). A univariate analysis was unable to show variables associated with influenza A(H1N1) 2009, whereas rhinorrhea was associated with viruses other than influenza (p = 0.04). Despite the A(H1N1) 2009 influenza pandemic, rhinovirus and other influenza viruses were also frequent causes of RTI in overseas travelers. Real-time reverse transcription-PCR and nasopharyngeal swab cultures are useful diagnostic tools for evaluating travelers with RTI. © 2011 International Society of Travel Medicine.

  7. A new look at an old virus: patterns of mutation accumulation in the human H1N1 influenza virus since 1918

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    Carter Robert W

    2012-10-01

    Full Text Available Abstract Background The H1N1 influenza A virus has been circulating in the human population for over 95 years, first manifesting itself in the pandemic of 1917–1918. Initial mortality was extremely high, but dropped exponentially over time. Influenza viruses have high mutation rates, and H1N1 has undergone significant genetic changes since 1918. The exact nature of H1N1 mutation accumulation over time has not been fully explored. Methods We have made a comprehensive historical analysis of mutational changes within H1N1 by examining over 4100 fully-sequenced H1N1 genomes. This has allowed us to examine the genetic changes arising within H1N1 from 1918 to the present. Results We document multiple extinction events, including the previously known extinction of the human H1N1 lineage in the 1950s, and an apparent second extinction of the human H1N1 lineage in 2009. These extinctions appear to be due to a continuous accumulation of mutations. At the time of its disappearance in 2009, the human H1N1 lineage had accumulated over 1400 point mutations (more than 10% of the genome, including approximately 330 non-synonymous changes (7.4% of all codons. The accumulation of both point mutations and non-synonymous amino acid changes occurred at constant rates (μ = 14.4 and 2.4 new mutations/year, respectively, and mutations accumulated uniformly across the entire influenza genome. We observed a continuous erosion over time of codon-specificity in H1N1, including a shift away from host (human, swine, and bird [duck] codon preference patterns. Conclusions While there have been numerous adaptations within the H1N1 genome, most of the genetic changes we document here appear to be non-adaptive, and much of the change appears to be degenerative. We suggest H1N1 has been undergoing natural genetic attenuation, and that significant attenuation may even occur during a single pandemic. This process may play a role in natural pandemic cessation and has apparently

  8. Prior infection of chickens with H1N1 or H1N2 avian influenza elicits partial heterologous protection against highly pathogenic H5N1.

    Science.gov (United States)

    Nfon, Charles; Berhane, Yohannes; Pasick, John; Embury-Hyatt, Carissa; Kobinger, Gary; Kobasa, Darwyn; Babiuk, Shawn

    2012-01-01

    There is a critical need to have vaccines that can protect against emerging pandemic influenza viruses. Commonly used influenza vaccines are killed whole virus that protect against homologous and not heterologous virus. Using chickens we have explored the possibility of using live low pathogenic avian influenza (LPAI) A/goose/AB/223/2005 H1N1 or A/WBS/MB/325/2006 H1N2 to induce immunity against heterologous highly pathogenic avian influenza (HPAI) A/chicken/Vietnam/14/2005 H5N1. H1N1 and H1N2 replicated in chickens but did not cause clinical disease. Following infection, chickens developed nucleoprotein and H1 specific antibodies, and reduced H5N1 plaque size in vitro in the absence of H5 neutralizing antibodies at 21 days post infection (DPI). In addition, heterologous cell mediated immunity (CMI) was demonstrated by antigen-specific proliferation and IFN-γ secretion in PBMCs re-stimulated with H5N1 antigen. Following H5N1 challenge of both pre-infected and naïve controls chickens housed together, all naïve chickens developed acute disease and died while H1N1 or H1N2 pre-infected chickens had reduced clinical disease and 70-80% survived. H1N1 or H1N2 pre-infected chickens were also challenged with H5N1 and naïve chickens placed in the same room one day later. All pre-infected birds were protected from H5N1 challenge but shed infectious virus to naïve contact chickens. However, disease onset, severity and mortality was reduced and delayed in the naïve contacts compared to directly inoculated naïve controls. These results indicate that prior infection with LPAI virus can generate heterologous protection against HPAI H5N1 in the absence of specific H5 antibody.

  9. Prior infection of chickens with H1N1 or H1N2 avian influenza elicits partial heterologous protection against highly pathogenic H5N1.

    Directory of Open Access Journals (Sweden)

    Charles Nfon

    Full Text Available There is a critical need to have vaccines that can protect against emerging pandemic influenza viruses. Commonly used influenza vaccines are killed whole virus that protect against homologous and not heterologous virus. Using chickens we have explored the possibility of using live low pathogenic avian influenza (LPAI A/goose/AB/223/2005 H1N1 or A/WBS/MB/325/2006 H1N2 to induce immunity against heterologous highly pathogenic avian influenza (HPAI A/chicken/Vietnam/14/2005 H5N1. H1N1 and H1N2 replicated in chickens but did not cause clinical disease. Following infection, chickens developed nucleoprotein and H1 specific antibodies, and reduced H5N1 plaque size in vitro in the absence of H5 neutralizing antibodies at 21 days post infection (DPI. In addition, heterologous cell mediated immunity (CMI was demonstrated by antigen-specific proliferation and IFN-γ secretion in PBMCs re-stimulated with H5N1 antigen. Following H5N1 challenge of both pre-infected and naïve controls chickens housed together, all naïve chickens developed acute disease and died while H1N1 or H1N2 pre-infected chickens had reduced clinical disease and 70-80% survived. H1N1 or H1N2 pre-infected chickens were also challenged with H5N1 and naïve chickens placed in the same room one day later. All pre-infected birds were protected from H5N1 challenge but shed infectious virus to naïve contact chickens. However, disease onset, severity and mortality was reduced and delayed in the naïve contacts compared to directly inoculated naïve controls. These results indicate that prior infection with LPAI virus can generate heterologous protection against HPAI H5N1 in the absence of specific H5 antibody.

  10. CD206+ Cell Number Differentiates Influenza A (H1N1pdm09 from Seasonal Influenza A Virus in Fatal Cases

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    Heidi G. Rodriguez-Ramirez

    2014-01-01

    Full Text Available In 2009, a new influenza A (H1N1 virus affected many persons around the world. There is an urgent need for finding biomarkers to distinguish between influenza A (H1N1pdm09 and seasonal influenza virus. We investigated these possible biomarkers in the lung of fatal cases of confirmed influenza A (H1N1pdm09. Cytokines (inflammatory and anti-inflammatory and cellular markers (macrophages and lymphocytes subpopulation markers were analyzed in lung tissue from both influenza A (H1N1pdm09 and seasonal influenza virus. High levels of IL-17, IFN-γ, and TNF-α positive cells were identical in lung tissue from the influenza A (H1N1pdm09 and seasonal cases when compared with healthy lung tissue (P<0.05. Increased IL-4+ cells, and CD4+ and CD14+ cells were also found in high levels in both influenza A (H1N1pdm09 and seasonal influenza virus (P<0.05. Low levels of CD206+ cells (marker of alternatively activated macrophages marker in lung were found in influenza A (H1N1pdm09 when compared with seasonal influenza virus (P<0.05, and the ratio of CD206/CD14+ cells was 2.5-fold higher in seasonal and noninfluenza group compared with influenza A (H1N1pdm09 (P<0.05. In conclusion, CD206+ cells differentiate between influenza A (H1N1pdm09 and seasonal influenza virus in lung tissue of fatal cases.

  11. Hemagglutinin 222D/G polymorphism facilitates fast intra-host evolution of pandemic (H1N1 2009 influenza A viruses.

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    Nora Seidel

    Full Text Available The amino acid substitution of aspartic acid to glycine in hemagglutinin (HA in position 222 (HA-D222G as well as HA-222D/G polymorphism of pandemic (H1N1 2009 influenza viruses (A(H1N1pdm09 were frequently reported in severe influenza in humans and mice. Their impact on viral pathogenicity and the course of influenza has been discussed controversially and the underlying mechanism remained unclarified. In the present study, BALB/c mice, infected with the once mouse lung- and cell-passaged A(H1N1pdm09 isolate A/Jena/5258/09 (mpJena/5258, developed severe pneumonia. From day 2 to 3 or 4 post infection (p.i. symptoms (body weight loss and clinical score continuously worsened. After a short disease stagnation or even recovery phase in most mice, severity of disease further increased on days 6 and 7 p.i. Thereafter, surviving mice recovered. A 45 times higher virus titer maximum in the lung than in the trachea on day 2 p.i. and significantly higher tracheal virus titers compared to lung on day 6 p.i. indicated changes in the organ tropism during infection. Sequence analysis revealed an HA-222D/G polymorphism. HA-D222 and HA-G222 variants co-circulated in lung and trachea. Whereas, HA-D222 variant predominated in the lung, HA-G222 became the major variant in the trachea after day 4 p.i. This was accompanied by lower neutralizing antibody titers and broader receptor recognition including terminal sialic acid α-2,3-linked galactose, which is abundant on mouse trachea epithelial cells. Plaque-purified HA-G222-mpJena/5258 virus induced severe influenza with maximum symptom on day 6 p.i. These results demonstrated for the first time that HA-222D/G quasispecies of A(H1N1pdm09 caused severe biphasic influenza because of fast viral intra-host evolution, which enabled partial antibody escape and minor changes in receptor binding.

  12. Genetic Characterization of H1N1 and H1N2 Influenza A Viruses Circulating in Ontario Pigs in 2012.

    Science.gov (United States)

    Grgić, Helena; Costa, Marcio; Friendship, Robert M; Carman, Susy; Nagy, Éva; Poljak, Zvonimir

    2015-01-01

    The objective of this study was to characterize H1N1 and H1N2 influenza A virus isolates detected during outbreaks of respiratory disease in pig herds in Ontario (Canada) in 2012. Six influenza viruses were included in analysis using full genome sequencing based on the 454 platform. In five H1N1 isolates, all eight segments were genetically related to 2009 pandemic virus (A(H1N1)pdm09). One H1N2 isolate had hemagglutinin (HA), polymerase A (PA) and non-structural (NS) genes closely related to A(H1N1)pdm09, and neuraminidase (NA), matrix (M), polymerase B1 (PB1), polymerase B2 (PB2), and nucleoprotein (NP) genes originating from a triple-reassortant H3N2 virus (tr H3N2). The HA gene of five Ontario H1 isolates exhibited high identity of 99% with the human A(H1N1)pdm09 [A/Mexico/InDRE4487/09] from Mexico, while one Ontario H1N1 isolate had only 96.9% identity with this Mexican virus. Each of the five Ontario H1N1 viruses had between one and four amino acid (aa) changes within five antigenic sites, while one Ontario H1N2 virus had two aa changes within two antigenic sites. Such aa changes in antigenic sites could have an effect on antibody recognition and ultimately have implications for immunization practices. According to aa sequence analysis of the M2 protein, Ontario H1N1 and H1N2 viruses can be expected to offer resistance to adamantane derivatives, but not to neuraminidase inhibitors.

  13. Genetic Characterization of H1N1 and H1N2 Influenza A Viruses Circulating in Ontario Pigs in 2012.

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    Helena Grgić

    Full Text Available The objective of this study was to characterize H1N1 and H1N2 influenza A virus isolates detected during outbreaks of respiratory disease in pig herds in Ontario (Canada in 2012. Six influenza viruses were included in analysis using full genome sequencing based on the 454 platform. In five H1N1 isolates, all eight segments were genetically related to 2009 pandemic virus (A(H1N1pdm09. One H1N2 isolate had hemagglutinin (HA, polymerase A (PA and non-structural (NS genes closely related to A(H1N1pdm09, and neuraminidase (NA, matrix (M, polymerase B1 (PB1, polymerase B2 (PB2, and nucleoprotein (NP genes originating from a triple-reassortant H3N2 virus (tr H3N2. The HA gene of five Ontario H1 isolates exhibited high identity of 99% with the human A(H1N1pdm09 [A/Mexico/InDRE4487/09] from Mexico, while one Ontario H1N1 isolate had only 96.9% identity with this Mexican virus. Each of the five Ontario H1N1 viruses had between one and four amino acid (aa changes within five antigenic sites, while one Ontario H1N2 virus had two aa changes within two antigenic sites. Such aa changes in antigenic sites could have an effect on antibody recognition and ultimately have implications for immunization practices. According to aa sequence analysis of the M2 protein, Ontario H1N1 and H1N2 viruses can be expected to offer resistance to adamantane derivatives, but not to neuraminidase inhibitors.

  14. Novel influenza A (H1N1) infection: chest CT findings from 21 cases in Seoul, Korea

    Energy Technology Data Exchange (ETDEWEB)

    Shim, S.S., E-mail: sinisim@ewha.ac.k [Department of Diagnostic Radiology and Center for Imaging Science, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul (Korea, Republic of); Kim, Y. [Department of Diagnostic Radiology and Center for Imaging Science, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul (Korea, Republic of); Ryu, Y.J. [Division of Pulmonary and Critical care medicine, Department of Internal Medicine, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul (Korea, Republic of)

    2011-02-15

    Aim: To retrospectively evaluate the computed tomography (CT) appearances of novel influenza A (H1N1) infection. Materials and methods: Chest CT images obtained at clinical presentation in 21 patients (eight men, 13 women; mean age, 37 years; age range, 6-82 years) with confirmed novel influenza A (H1N1) infection were assessed. The radiological appearances of pulmonary parenchymal abnormalities, distribution, and extent of involvement on initial chest CT images were documented. The study group was divided on the basis of age [group 1, patients <18 years old (n = 8); group 2, patients {>=}18 years old (n = 13)]. Medical records were reviewed for underlying medical conditions and laboratory findings. The occurrence of recognizable CT patterns was compared for each group using the images from the initial CT examination. Results: The most common CT pattern observed in all patients was ground-glass attenuated (GGA) lesions (20/21, 95%). Bronchial wall thickening (9/21, 43%) was the second most common CT finding. Other common CT findings were consolidation (6/21, 29%), pleural effusion (6/21, 29%), pneumothorax or pneumomediastinum (5/21, 24%), and atelectasis (5/21, 24%). Among these, atelectasis and pneumomediastinum (pneumothorax) were only observed in group 1. The GGA lesions showed predilections for diffuse multifocal (10/20, 50%) or lower zone (8/20, 40%) distribution. Involvement of central lung parenchyma (12/20, 60%) was more common than a mixed peripheral and central pattern (6/20, 30%) or a subpleural pattern (2/20, 10%) at the time of presentation. Patchy GGA lesions were more frequent (18/20, 90%) than diffuse GGA lesions, and 75% (15/20) of these lesions had a bronchovascular distribution. Bilateral disease was present in all patients with GGA lesions. Bronchial wall thickening was predominantly centrally located and the distribution of the consolidation was non-specific. Conclusion: The predominantly centrally located GGA lesions, with common multifocal

  15. Novel influenza A (H1N1) infection: chest CT findings from 21 cases in Seoul, Korea

    International Nuclear Information System (INIS)

    Shim, S.S.; Kim, Y.; Ryu, Y.J.

    2011-01-01

    Aim: To retrospectively evaluate the computed tomography (CT) appearances of novel influenza A (H1N1) infection. Materials and methods: Chest CT images obtained at clinical presentation in 21 patients (eight men, 13 women; mean age, 37 years; age range, 6-82 years) with confirmed novel influenza A (H1N1) infection were assessed. The radiological appearances of pulmonary parenchymal abnormalities, distribution, and extent of involvement on initial chest CT images were documented. The study group was divided on the basis of age [group 1, patients <18 years old (n = 8); group 2, patients ≥18 years old (n = 13)]. Medical records were reviewed for underlying medical conditions and laboratory findings. The occurrence of recognizable CT patterns was compared for each group using the images from the initial CT examination. Results: The most common CT pattern observed in all patients was ground-glass attenuated (GGA) lesions (20/21, 95%). Bronchial wall thickening (9/21, 43%) was the second most common CT finding. Other common CT findings were consolidation (6/21, 29%), pleural effusion (6/21, 29%), pneumothorax or pneumomediastinum (5/21, 24%), and atelectasis (5/21, 24%). Among these, atelectasis and pneumomediastinum (pneumothorax) were only observed in group 1. The GGA lesions showed predilections for diffuse multifocal (10/20, 50%) or lower zone (8/20, 40%) distribution. Involvement of central lung parenchyma (12/20, 60%) was more common than a mixed peripheral and central pattern (6/20, 30%) or a subpleural pattern (2/20, 10%) at the time of presentation. Patchy GGA lesions were more frequent (18/20, 90%) than diffuse GGA lesions, and 75% (15/20) of these lesions had a bronchovascular distribution. Bilateral disease was present in all patients with GGA lesions. Bronchial wall thickening was predominantly centrally located and the distribution of the consolidation was non-specific. Conclusion: The predominantly centrally located GGA lesions, with common multifocal or

  16. Evaluation of the Cepheid Xpert Flu Assay for rapid identification and differentiation of influenza A, influenza A 2009 H1N1, and influenza B viruses.

    Science.gov (United States)

    Novak-Weekley, S M; Marlowe, E M; Poulter, M; Dwyer, D; Speers, D; Rawlinson, W; Baleriola, C; Robinson, C C

    2012-05-01

    The Xpert Flu Assay cartridge is a next-generation nucleic acid amplification system that provides multiplexed PCR detection of the influenza A, influenza A 2009 H1N1, and influenza B viruses in approximately 70 min with minimal hands-on time. Six laboratories participated in a clinical trial comparing the results of the new Cepheid Xpert Flu Assay to those of culture or real-time PCR with archived and prospectively collected nasal aspirate-wash (NA-W) specimens and nasopharyngeal (NP) swabs from children and adults. Discrepant results were resolved by DNA sequence analysis. After discrepant-result analysis, the sensitivities of the Xpert Flu Assay for prospective NA-W specimens containing the influenza A, influenza A 2009 H1N1, and influenza B viruses compared to those of culture were 90.0%, 100%, and 100%, respectively, while the sensitivities of the assay for prospective NP swabs compared to those of culture were 100%, 100%, and 100%, respectively. The sensitivities of the Xpert Flu Assay for archived NA-W specimens compared to those of Gen-Probe ProFlu+ PCR for the influenza A, influenza A 2009 H1N1, and influenza B viruses were 99.4%, 98.4%, and 100%, respectively, while the sensitivities of the Xpert Flu Assay for archived NP swabs compared to those of ProFlu+ were 98.1%, 100%, and 93.8%, respectively. The sensitivities of the Xpert Flu Assay with archived NP specimens compared to those of culture for the three targets were 97.5%, 100%, and 93.8%, respectively. We conclude that the Cepheid Xpert Flu Assay is an accurate and rapid method that is suitable for on-demand testing for influenza viral infection.

  17. The new school absentees reporting system for pandemic influenza A/H1N1 2009 infection in Japan.

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    Takeshi Suzue

    Full Text Available To evaluate the new Japanese School Absentees Reporting System for Infectious Disease (SARSID for pandemic influenza A/H1N1 2009 infection in comparison with the National epidemiological Surveillance of Infectious Disease (NESID.We used data of 53,223 students (97.7% in Takamatsu city Japan. Data regarding school absentees in SARSID was compared with that in NESID from Oct 13, 2009 to Jan 12, 2010.Similar trends were observed both in SARSID and NESID. However, the epidemic trend for influenza in SARSID was thought to be more sensitive than that in NESID.The epidemic trend for influenza among school-aged children could be easily and rapidly assessed by SARSID compared to NESID. SARSID might be useful for detecting the epidemic trend of influenza.

  18. The impact of the pandemic influenza A(H1N1) 2009 virus on seasonal influenza A viruses in the southern hemisphere, 2009.

    Science.gov (United States)

    Blyth, C C; Kelso, A; McPhie, K A; Ratnamohan, V M; Catton, M; Druce, J D; Smith, D W; Williams, S H; Huang, Q S; Lopez, L; Schoub, B D; Venter, M; Dwyer, D E

    2010-08-05

    Data collected over winter 2009 by five World Health Organisation National Influenza Centres in the southern hemisphere were used to examine the circulation of pandemic and seasonal influenza A strains during the first pandemic wave in the southern hemisphere.There is compelling evidence that the pandemic influenza A(H1N1) 2009 virus significantly displaced seasonal influenza A(H1N1) and, to a lesser extent, A(H3N2) viruses circulating in the southern hemisphere. Complete replacement of seasonal influenza A strains, however, was not observed during the first pandemic wave.

  19. Adaptive evolution during the establishment of European avian-like H1N1 influenza A virus in swine.

    Science.gov (United States)

    Joseph, Udayan; Vijaykrishna, Dhanasekaran; Smith, Gavin J D; Su, Yvonne C F

    2018-04-01

    An H1N1 subtype influenza A virus with all eight gene segments derived from wild birds (including mallards), ducks and chickens, caused severe disease outbreaks in swine populations in Europe beginning in 1979 and successfully adapted to form the European avian-like swine (EA-swine) influenza lineage. Genes of the EA-swine lineage that are clearly segregated from its closest avian relatives continue to circulate in swine populations globally and represent a unique opportunity to study the adaptive process of an avian-to-mammalian cross-species transmission. Here, we used a relaxed molecular clock model to test whether the EA-swine virus originated through the introduction of a single avian ancestor as an entire genome, followed by an analysis of host-specific selection pressures among different gene segments. Our data indicated independent introduction of gene segments via transmission of avian viruses into swine followed by reassortment events that occurred at least 1-4 years prior to the EA-swine outbreak. All EA-swine gene segments exhibit greater selection pressure than avian viruses, reflecting both adaptive pressures and relaxed selective constraints that are associated with host switching. Notably, we identified key amino acid mutations in the viral surface proteins (H1 and N1) that play a role in adaptation to new hosts. Following the establishment of EA-swine lineage, we observed an increased frequency of intrasubtype reassortment of segments compared to the earlier strains that has been associated with adaptive amino acid replacements, disease severity and vaccine escape. Taken together, our study provides key insights into the adaptive changes in viral genomes following the transmission of avian influenza viruses to swine and the early establishment of the EA-swine lineage.

  20. Seasonal Influenza A H1N1pdm09 Virus and Severe Outcomes: A Reason for Broader Vaccination in Non-Elderly, At-Risk People.

    Directory of Open Access Journals (Sweden)

    Elisa Minchole

    Full Text Available Recent pandemics of influenza A H1N1pdm09 virus have caused severe illness, especially in young people. Very few studies on influenza A H1N1pdm09 in post-pandemic periods exist, and there is no information on the severity of both seasonal influenza A(H1N1 and A(H3N2 from the same season, adjusting for potential confounders, including vaccine.We performed a retrospective observational study of adults hospitalized during the 2014 season with influenza A(H1N1 or A(H3N2. All patients underwent the same diagnostic and therapeutic protocol in a single hospital, including early Oseltamivir therapy. We included 234 patients: 146 (62.4% influenza A(H1N1 and 88 (37.6% A(H3N2. A(H1N1 patients were younger (p<0.01, developed more pneumonia (p<0.01, respiratory complications (p = 0.015, ARDS (p = 0.047, and septic shock (p = 0.049, were more frequently admitted to the ICU (p = 0.022, required IMV (p = 0.049, and were less frequently vaccinated (p = 0.008. After adjusting for age, comorbidities, time from onset of illness, and vaccine status, influenza A(H1N1 (OR, 2.525, coinfection (OR, 2.821, and no vaccination (OR, 3.086 were independent risk factors for severe disease.Hospitalized patients with influenza A(H1N1 were more than twice as likely to have severe influenza. They were younger and most had not received the vaccine. Our findings suggest that seasonal influenza A(H1N1 maintains some features of pandemic viruses, and recommend wider use of vaccination in younger adult high-risk patients.

  1. Isolation and genetic characterization of avian-like H1N1 and novel ressortant H1N2 influenza viruses from pigs in China.

    Science.gov (United States)

    Yu, Hai; Zhang, Peng-Chao; Zhou, Yan-Jun; Li, Guo-Xin; Pan, Jie; Yan, Li-Ping; Shi, Xiao-Xiao; Liu, Hui-Li; Tong, Guang-Zhi

    2009-08-21

    As pigs are susceptible to both human and avian influenza viruses, they have been proposed to be intermediate hosts or mixing vessels for the generation of pandemic influenza viruses through reassortment or adaptation to the mammalian host. In this study, we reported avian-like H1N1 and novel ressortant H1N2 influenza viruses from pigs in China. Homology and phylogenetic analyses showed that the H1N1 virus (A/swine/Zhejiang/1/07) was closely to avian-like H1N1 viruses and seemed to be derived from the European swine H1N1 viruses, which was for the first time reported in China; and the two H1N2 viruses (A/swine/Shanghai/1/07 and A/swine/Guangxi/13/06) were novel ressortant H1N2 influenza viruses containing genes from the classical swine (HA, NP, M and NS), human (NA and PB1) and avian (PB2 and PA) lineages, which indicted that the reassortment among human, avian, and swine influenza viruses had taken place in pigs in China and resulted in the generation of new viruses. The isolation of avian-like H1N1 influenza virus originated from the European swine H1N1 viruses, especially the emergence of two novel ressortant H1N2 influenza viruses provides further evidence that pigs serve as intermediate hosts or "mixing vessels", and swine influenza virus surveillance in China should be given a high priority.

  2. In silico analysis and identification of novel inhibitor for new H1N1 swine influenza virus

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    Manjunath Dammalli

    2014-09-01

    Full Text Available Objective: To identify alternative drug for the treatment of pandemic disease caused by influenza virus. Methods: The structure based drug design approach was employed. New sequence was employed to build the N1 simulation structure by homology modeling which was further checked for high reliability by verify score and Ramachandran plot. Evaluation of drug likeness and absorption, distribution, metabolism, excretion, toxicity showed that the ligands satisfy all the properties to be used as a drug. Docking studies were performed using LeadIT and docking scores indicated good binding energy values towards N1. Results: Four candidates were screened and suggested as potent target candidates from the docking studies. The screened compounds from Stemonaceae family illustrated better activity compared to the drugs which are already present in the market. Conclusions: The results may help to find the alternative drug to solve the drug-resistant problem and stimulate designing more effective drugs against 2009-H1N1 influenza pandemic, yet pharmacological studies have to confirm it.

  3. Protection of human influenza vaccines against a reassortant swine influenza virus of pandemic H1N1 origin using a pig model.

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    Arunorat, Jirapat; Charoenvisal, Nataya; Woonwong, Yonlayong; Kedkovid, Roongtham; Jittimanee, Supattra; Sitthicharoenchai, Panchan; Kesdangsakonwut, Sawang; Poolperm, Pariwat; Thanawongnuwech, Roongroje

    2017-10-01

    Since the pandemic H1N1 emergence in 2009 (pdmH1N1), many reassortant pdmH1N1 viruses emerged and found circulating in the pig population worldwide. Currently, commercial human subunit vaccines are used commonly to prevent the influenza symptom based on the WHO recommendation. In case of current reassortant swine influenza viruses transmitting from pigs to humans, the efficacy of current human influenza vaccines is of interest. In this study, influenza A negative pigs were vaccinated with selected commercial human subunit vaccines and challenged with rH3N2. All sera were tested with both HI and SN assays using four representative viruses from the surveillance data in 2012 (enH1N1, pdmH1N1, rH1N2 and rH3N2). The results showed no significant differences in clinical signs and macroscopic and microscopic findings among groups. However, all pig sera from vaccinated groups had protective HI titers to the enH1N1, pdmH1N1 and rH1N2 at 21DPV onward and had protective SN titers only to pdmH1N1and rH1N2 at 21DPV onward. SN test results appeared more specific than those of HI tests. All tested sera had no cross-reactivity against the rH3N2. Both studied human subunit vaccines failed to protect and to stop viral shedding with no evidence of serological reaction against rH3N2. SIV surveillance is essential for monitoring a novel SIV emergence potentially for zoonosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. In situ molecular identification of the Influenza A (H1N1 2009 Neuraminidase in patients with severe and fatal infections during a pandemic in Mexico City

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    Ocadiz-Delgado Rodolfo

    2013-01-01

    Full Text Available Abstract Background In April 2009, public health surveillance detected an increased number of influenza-like illnesses in Mexico City’s hospitals. The etiological agent was subsequently determined to be a spread of a worldwide novel influenza A (H1N1 triple reassortant. The purpose of the present study was to demonstrate that molecular detection of pandemic influenza A (H1N1 2009 strains is possible in archival material such as paraffin-embedded lung samples. Methods In order to detect A (H1N1 virus sequences in archived biological samples, eight paraffin-embedded lung samples from patients who died of pneumonia and respiratory failure were tested for influenza A (H1N1 Neuraminidase (NA RNA using in situ RT-PCR. Results We detected NA transcripts in 100% of the previously diagnosed A (H1N1-positive samples as a cytoplasmic signal. No expression was detected by in situ RT-PCR in two Influenza-like Illness A (H1N1-negative patients using standard protocols nor in a non-related cervical cell line. In situ relative transcription levels correlated with those obtained when in vitro RT-PCR assays were performed. Partial sequences of the NA gene from A (H1N1-positive patients were obtained by the in situ RT-PCR-sequencing method. Sequence analysis showed 98% similarity with influenza viruses reported previously in other places. Conclusions We have successfully amplified specific influenza A (H1N1 NA sequences using stored clinical material; results suggest that this strategy could be useful when clinical RNA samples are quantity limited, or when poor quality is obtained. Here, we provide a very sensitive method that specifically detects the neuraminidase viral RNA in lung samples from patients who died from pneumonia caused by Influenza A (H1N1 outbreak in Mexico City.

  5. NS Segment of a 1918 Influenza A Virus-Descendent Enhances Replication of H1N1pdm09 and Virus-Induced Cellular Immune Response in Mammalian and Avian Systems

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    Petersen, Henning; Mostafa, Ahmed; Tantawy, Mohamed A.; Iqbal, Azeem A.; Hoffmann, Donata; Tallam, Aravind; Selvakumar, Balachandar; Pessler, Frank; Beer, Martin; Rautenschlein, Silke; Pleschka, Stephan

    2018-01-01

    The 2009 pandemic influenza A virus (IAV) H1N1 strain (H1N1pdm09) has widely spread and is circulating in humans and swine together with other human and avian IAVs. This fact raises the concern that reassortment between H1N1pdm09 and co-circulating viruses might lead to an increase of H1N1pdm09 pathogenicity in different susceptible host species. Herein, we explored the potential of different NS segments to enhance the replication dynamics, pathogenicity and host range of H1N1pdm09 strain A/Giessen/06/09 (Gi-wt). The NS segments were derived from (i) human H1N1- and H3N2 IAVs, (ii) highly pathogenic- (H5- or H7-subtypes) or (iii) low pathogenic avian influenza viruses (H7- or H9-subtypes). A significant increase of growth kinetics in A549 (human lung epithelia) and NPTr (porcine tracheal epithelia) cells was only noticed in vitro for the reassortant Gi-NS-PR8 carrying the NS segment of the 1918-descendent A/Puerto Rico/8/34 (PR8-wt, H1N1), whereas all other reassortants showed either reduced or comparable replication efficiencies. Analysis using ex vivo tracheal organ cultures of turkeys (TOC-Tu), a species susceptible to IAV H1N1 infection, demonstrated increased replication of Gi-NS-PR8 compared to Gi-wt. Also, Gi-NS-PR8 induced a markedly higher expression of immunoregulatory and pro-inflammatory cytokines, chemokines and interferon-stimulated genes in A549 cells, THP-1-derived macrophages (dHTP) and TOC-Tu. In vivo, Gi-NS-PR8 induced an earlier onset of mortality than Gi-wt in mice, whereas, 6-week-old chickens were found to be resistant to both viruses. These data suggest that the specific characteristics of the PR8 NS segments can impact on replication, virus induced cellular immune responses and pathogenicity of the H1N1pdm09 in different avian and mammalian host species. PMID:29623073

  6. Mutation analysis of 2009 pandemic influenza A(H1N1 viruses collected in Japan during the peak phase of the pandemic.

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    Jean-Étienne Morlighem

    Full Text Available BACKGROUND: Pandemic influenza A(H1N1 virus infection quickly circulated worldwide in 2009. In Japan, the first case was reported in May 2009, one month after its outbreak in Mexico. Thereafter, A(H1N1 infection spread widely throughout the country. It is of great importance to profile and understand the situation regarding viral mutations and their circulation in Japan to accumulate a knowledge base and to prepare clinical response platforms before a second pandemic (pdm wave emerges. METHODOLOGY: A total of 253 swab samples were collected from patients with influenza-like illness in the Osaka, Tokyo, and Chiba areas both in May 2009 and between October 2009 and January 2010. We analyzed partial sequences of the hemagglutinin (HA and neuraminidase (NA genes of the 2009 pdm influenza virus in the collected clinical samples. By phylogenetic analysis, we identified major variants of the 2009 pdm influenza virus and critical mutations associated with severe cases, including drug-resistance mutations. RESULTS AND CONCLUSIONS: Our sequence analysis has revealed that both HA-S220T and NA-N248D are major non-synonymous mutations that clearly discriminate the 2009 pdm influenza viruses identified in the very early phase (May 2009 from those found in the peak phase (October 2009 to January 2010 in Japan. By phylogenetic analysis, we found 14 micro-clades within the viruses collected during the peak phase. Among them, 12 were new micro-clades, while two were previously reported. Oseltamivir resistance-related mutations, i.e., NA-H275Y and NA-N295S, were also detected in sporadic cases in Osaka and Tokyo.

  7. Evidence of reassortment of pandemic H1N1 influenza virus in swine in Argentina: are we facing the expansion of potential epicenters of influenza emergence?

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    Pereda, Ariel; Rimondi, Agustina; Cappuccio, Javier; Sanguinetti, Ramon; Angel, Matthew; Ye, Jianqiang; Sutton, Troy; Dibárbora, Marina; Olivera, Valeria; Craig, Maria I.; Quiroga, Maria; Machuca, Mariana; Ferrero, Andrea; Perfumo, Carlos; Perez, Daniel R.

    2011-01-01

    Please cite this paper as: Pereda et al. (2011) Evidence of reassortment of pandemic H1N1 influenza virus in swine in Argentina: are we facing the expansion of potential epicenters of influenza emergence? Influenza and Other Respiratory Viruses 5(6), 409–412. In this report, we describe the occurrence of two novel swine influenza viruses (SIVs) in pigs in Argentina. These viruses are the result of two independent reassortment events between the H1N1 pandemic influenza virus (H1N1pdm) and human‐like SIVs, showing the constant evolution of influenza viruses at the human–swine interface and the potential health risk of H1N1pdm as it appears to be maintained in the swine population. It must be noted that because of the lack of information regarding the circulation of SIVs in South America, we cannot discard the possibility that ancestors of the H1N1pdm or other SIVs have been present in this part of the world. More importantly, these findings suggest an ever‐expanding geographic range of potential epicenters of influenza emergence with public health risks. PMID:21668680

  8. Novel reassortant influenza A(H1N2) virus derived from A(H1N1)pdm09 virus isolated from swine, Japan, 2012.

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    Kobayashi, Miho; Takayama, Ikuyo; Kageyama, Tsutomu; Tsukagoshi, Hiroyuki; Saitoh, Mika; Ishioka, Taisei; Yokota, Yoko; Kimura, Hirokazu; Tashiro, Masato; Kozawa, Kunihisa

    2013-12-01

    We isolated a novel influenza virus A(H1N2) strain from a pig on January 13, 2012, in Gunma Prefecture, Japan. Phylogenetic analysis showed that the strain was a novel type of double-reassortant virus derived from the swine influenza virus strains H1N1pdm09 and H1N2, which were prevalent in Gunma at that time.

  9. An Analysis of 332 Fatalities Infected with Pandemic 2009 Influenza A (H1N1) in Argentina

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    Balanzat, Ana M.; Hertlein, Christian; Apezteguia, Carlos; Bonvehi, Pablo; Cámera, Luis; Gentile, Angela; Rizzo, Oscar; Gómez-Carrillo, Manuel; Coronado, Fatima; Azziz-Baumgartner, Eduardo; Chávez, Pollyanna R.; Widdowson, Marc-Alain

    2012-01-01

    Background The apparent high number of deaths in Argentina during the 2009 pandemic led to concern that the influenza A H1N1pdm disease was different there. We report the characteristics and risk factors for influenza A H1N1pdm fatalities. Methods We identified laboratory-confirmed influenza A H1N1pdm fatalities occurring during June-July 2009. Physicians abstracted data on age, sex, time of onset of illness, medical history, clinical presentation at admission, laboratory, treatment, and outcomes using standardize questionnaires. We explored the characteristics of fatalities according to their age and risk group. Results Of 332 influenza A H1N1pdm fatalities, 226 (68%) were among persons aged Argentina, though timeliness of antiviral treatment improved during the pandemic. PMID:22506006

  10. New Orf virus (Parapoxvirus) recombinant expressing H5 hemagglutinin protects mice against H5N1 and H1N1 influenza A virus.

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    Rohde, Jörg; Amann, Ralf; Rziha, Hanns-Joachim

    2013-01-01

    Previously we demonstrated the versatile utility of the Parapoxvirus Orf virus (ORFV) as a vector platform for the development of potent recombinant vaccines. In this study we present the generation of new ORFV recombinants expressing the hemagglutinin (HA) or nucleoprotein (NP) of the highly pathogenic avian influenza virus (HPAIV) H5N1. Correct foreign gene expression was examined in vitro by immunofluorescence, Western blotting and flow cytometry. The protective potential of both recombinants was evaluated in the mouse challenge model. Despite adequate expression of NP, the recombinant D1701-V-NPh5 completely failed to protect mice from lethal challenge. However, the H5 HA-expressing recombinant D1701-V-HAh5n mediated solid protection in a dose-dependent manner. Two intramuscular (i.m.) injections of the HA-expressing recombinant protected all animals from lethal HPAIV infection without loss of body weight. Notably, the immunized mice resisted cross-clade H5N1 and heterologous H1N1 (strain PR8) influenza virus challenge. In vivo antibody-mediated depletion of CD4-positive and/or CD8-posititve T-cell subpopulations during immunization and/or challenge infection implicated the relevance of CD4-positive T-cells for induction of protective immunity by D1701-V-HAh5n, whereas the absence of CD8-positive T-cells did not significantly influence protection. In summary, this study validates the potential of the ORFV vectored vaccines also to combat HPAIV.

  11. Determinants of vaccine immunogenicity in HIV-infected pregnant women: analysis of B and T cell responses to pandemic H1N1 monovalent vaccine.

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    Adriana Weinberg

    Full Text Available Influenza infections have high frequency and morbidity in HIV-infected pregnant women, underscoring the importance of vaccine-conferred protection. To identify the factors that determine vaccine immunogenicity in this group, we characterized the relationship of B- and T-cell responses to pandemic H1N1 (pH1N1 vaccine with HIV-associated immunologic and virologic characteristics. pH1N1 and seasonal-H1N1 (sH1N1 antibodies were measured in 119 HIV-infected pregnant women after two double-strength pH1N1 vaccine doses. pH1N1-IgG and IgA B-cell FluoroSpot, pH1N1- and sH1N1-interferon γ (IFNγ and granzyme B (GrB T-cell FluoroSpot, and flow cytometric characterization of B- and T-cell subsets were performed in 57 subjects. pH1N1-antibodies increased after vaccination, but less than previously described in healthy adults. pH1N1-IgG memory B cells (Bmem increased, IFNγ-effector T-cells (Teff decreased, and IgA Bmem and GrB Teff did not change. pH1N1-antibodies and Teff were significantly correlated with each other and with sH1N1-HAI and Teff, respectively, before and after vaccination. pH1N1-antibody responses to the vaccine significantly increased with high proportions of CD4+, low CD8+ and low CD8+HLADR+CD38+ activated (Tact cells. pH1N1-IgG Bmem responses increased with high proportions of CD19+CD27+CD21- activated B cells (Bact, high CD8+CD39+ regulatory T cells (Treg, and low CD19+CD27-CD21- exhausted B cells (Bexhaust. IFNγ-Teff responses increased with low HIV plasma RNA, CD8+HLADR+CD38+ Tact, CD4+FoxP3+ Treg and CD19+IL10+ Breg. In conclusion, pre-existing antibody and Teff responses to sH1N1 were associated with increased responses to pH1N1 vaccination in HIV-infected pregnant women suggesting an important role for heterosubtypic immunologic memory. High CD4+% T cells were associated with increased, whereas high HIV replication, Tact and Bexhaust were associated with decreased vaccine immunogenicity. High Treg increased antibody responses but

  12. Molecular characterization of a novel reassortant H1N2 influenza virus containing genes from the 2009 pandemic human H1N1 virus in swine from eastern China.

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    Peng, Xiuming; Wu, Haibo; Xu, Lihua; Peng, Xiaorong; Cheng, Linfang; Jin, Changzhong; Xie, Tiansheng; Lu, Xiangyun; Wu, Nanping

    2016-06-01

    Pandemic outbreaks of H1N1 swine influenza virus have been reported since 2009. Reassortant H1N2 viruses that contain genes from the pandemic H1N1 virus have been isolated in Italy and the United States. However, there is limited information regarding the molecular characteristics of reassortant H1N2 swine influenza viruses in eastern China. Active influenza surveillance programs in Zhejiang Province identified a novel H1N2 influenza virus isolated from pigs displaying clinical signs of influenza virus infection. Whole-genome sequencing was performed and this strain was compared with other influenza viruses available in GenBank. Phylogenetic analysis suggested that the novel strain contained genes from the 2009 pandemic human H1N1 and swine H3N2 viruses. BALB/c mice were infected with the isolated virus to assess its virulence in mice. While the novel H1N2 isolate replicated well in mice, it was found to be less virulent. These results provide additional evidence that swine serve as intermediate hosts or 'mixing vessels' for novel influenza viruses. They also emphasize the importance of surveillance in the swine population for use as an early warning system for influenza outbreaks in swine and human populations.

  13. Seroprevalence of three influenza A viruses (H1N1, H3N2, and H3N8) in pet dogs presented to a veterinary hospital in Ohio.

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    Jang, Hyesun; Jackson, Yasmine K; Daniels, Joshua B; Ali, Ahmed; Kang, Kyung-Il; Elaish, Mohamed; Lee, Chang-Won

    2017-08-31

    The prevalence of canine H3N8 influenza and human H1N1 and H3N2 influenza in dogs in Ohio was estimated by conducting serologic tests on 1,082 canine serum samples. In addition, risk factors, such as health status and age were examined. The prevalences of human H1N1, H3N2, and canine H3N8 influenzas were 4.0%, 2.4%, and 2.3%, respectively. Two samples were seropositive for two subtypes (H1N1 and H3N2; H1N1 and canine influenza virus [CIV] H3N8). Compared to healthy dogs, dogs with respiratory signs were 5.795 times more likely to be seropositive against H1N1 virus ( p = 0.042). The prevalence of human flu infection increased with dog age and varied by serum collection month. The commercial enzyme-linked immunosorbent assay used in this study did not detect nucleoprotein-specific antibodies from many hemagglutination inhibition positive sera, which indicates a need for the development and validation of rapid tests for influenza screening in canine populations. In summary, we observed low exposure of dogs to CIV and human influenza viruses in Ohio but identified potential risk factors for consideration in future investigations. Our findings support the need for establishment of reliable diagnostic standards for serologic detection of influenza infection in canine species.

  14. Swine Influenza Virus PA and Neuraminidase Gene Reassortment into Human H1N1 Influenza Virus Is Associated with an Altered Pathogenic Phenotype Linked to Increased MIP-2 Expression.

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    Dlugolenski, Daniel; Jones, Les; Howerth, Elizabeth; Wentworth, David; Tompkins, S Mark; Tripp, Ralph A

    2015-05-01

    Swine are susceptible to infection by both avian and human influenza viruses, and this feature is thought to contribute to novel reassortant influenza viruses. In this study, the influenza virus reassortment rate in swine and human cells was determined. Coinfection of swine cells with 2009 pandemic H1N1 virus (huH1N1) and an endemic swine H1N2 (A/swine/Illinois/02860/09) virus (swH1N2) resulted in a 23% reassortment rate that was independent of α2,3- or α2,6-sialic acid distribution on the cells. The reassortants had altered pathogenic phenotypes linked to introduction of the swine virus PA and neuraminidase (NA) into huH1N1. In mice, the huH1N1 PA and NA mediated increased MIP-2 expression early postinfection, resulting in substantial pulmonary neutrophilia with enhanced lung pathology and disease. The findings support the notion that swine are a mixing vessel for influenza virus reassortants independent of sialic acid distribution. These results show the potential for continued reassortment of the 2009 pandemic H1N1 virus with endemic swine viruses and for reassortants to have increased pathogenicity linked to the swine virus NA and PA genes which are associated with increased pulmonary neutrophil trafficking that is related to MIP-2 expression. Influenza A viruses can change rapidly via reassortment to create a novel virus, and reassortment can result in possible pandemics. Reassortments among subtypes from avian and human viruses led to the 1957 (H2N2 subtype) and 1968 (H3N2 subtype) human influenza pandemics. Recent analyses of circulating isolates have shown that multiple genes can be recombined from human, avian, and swine influenza viruses, leading to triple reassortants. Understanding the factors that can affect influenza A virus reassortment is needed for the establishment of disease intervention strategies that may reduce or preclude pandemics. The findings from this study show that swine cells provide a mixing vessel for influenza virus reassortment

  15. Phosphatidyl Inositol 3 Kinase-Gamma Balances Antiviral and Inflammatory Responses During Influenza A H1N1 Infection: From Murine Model to Genetic Association in Patients

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    Cristiana C. Garcia

    2018-05-01

    Full Text Available Influenza A virus (IAV infection causes severe pulmonary disease characterized by intense leukocyte infiltration. Phosphoinositide-3 kinases (PI3Ks are central signaling enzymes, involved in cell growth, survival, and migration. Class IB PI3K or phosphatidyl inositol 3 kinase-gamma (PI3Kγ, mainly expressed by leukocytes, is involved in cell migration during inflammation. Here, we investigated the contribution of PI3Kγ for the inflammatory and antiviral responses to IAV. PI3Kγ knockout (KO mice were highly susceptible to lethality following infection with influenza A/WSN/33 H1N1. In the early time points of infection, infiltration of neutrophils was higher than WT mice whereas type-I and type-III IFN expression and p38 activation were reduced in PI3Kγ KO mice resulting in higher viral loads when compared with WT mice. Blockade of p38 in WT macrophages infected with IAV reduced levels of interferon-stimulated gene 15 protein to those induced in PI3Kγ KO macrophages, suggesting that p38 is downstream of antiviral responses mediated by PI3Kγ. PI3Kγ KO-derived fibroblasts or macrophages showed reduced type-I IFN transcription and altered pro-inflammatory cytokines suggesting a cell autonomous imbalance between inflammatory and antiviral responses. Seven days after IAV infection, there were reduced infiltration of natural killer cells and CD8+ T lymphocytes, increased concentration of inflammatory cytokines in bronchoalveolar fluid, reduced numbers of resolving macrophages, and IL-10 levels in PI3Kγ KO. This imbalanced environment in PI3Kγ KO-infected mice culminated in enhanced lung neutrophil infiltration, reactive oxygen species release, and lung damage that together with the increased viral loads, contributed to higher mortality in PI3Kγ KO mice compared with WT mice. In humans, we tested the genetic association of disease severity in influenza A/H1N1pdm09-infected patients with three potentially functional PIK3CG single

  16. A highly pathogenic avian influenza virus H5N1 with 2009 pandemic H1N1 internal genes demonstrated increased replication and transmission in pigs

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    This study investigated the pathogenicity and transmissibility of a reverse-genetics derived highly pathogenic avian influenza (HPAI) H5N1 influenza A virus (IAV), A/Iraq/775/06, and a reassortant virus comprised of the HA and NA from A/Iraq/775/06 and the internal genes of a 2009 pandemic H1N1, A/N...

  17. Antiviral therapy and outcomes of patients with pneumonia caused by influenza A pandemic (H1N1 virus.

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    Shi-gui Yang

    Full Text Available BACKGROUND: There is limited data on the clinical outcome of patients with pandemic H1N1 (pH1N1 pneumonia who received oseltamivir treatment, especially when the treatment was administered more than 48 hours after symptom onset. METHODS: During the pandemic in 2009, a cohort of pH1N1 influenza pneumonia was built in China, and their clinical information was collected systematically, and analyzed with Cox models. RESULTS: 920 adults and 541 children with pneumonia who didn't receive corticosteroids were analyzed. In-hospital mortality was higher in adults who did not receive antiviral therapy (18.2% than those with who received oseltamivir ≤ 2 days (2.9%, between 2-5 days (4.6% and >5 days after illness onset (4.9%, p5 days, respectively. For males patients, aged ≥ 14 years and baseline PaO(2/FiO(23.8 mg/kg/d did not improve clinical outcome (mortality, higher dose 2.5% vs standard dose 2.8%, p>0.05. CONCLUSIONS: Antiviral therapy might reduce mortality of patients with pH1N1 pneumonia, even when initiated more than 48 hours after onset of illness. Greater protective effects might be in males, patients aged 14-60 years, and patients with PaO(2/FiO(2<200.

  18. Desempeño de la prueba de inmunofluorescencia directa en el diagnóstico del virus Influenza A(H1N1 Direct immunofluorescence assay performance in diagnosis of the Influenza A(H1N1 virus

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    Luis Pianciola

    2010-06-01

    Full Text Available El 25 de abril de 2009, a menos de un mes de la detección en México del primer humano con virus Influenza A(H1N1, la enfermedad ya se había propagado a más de 40 países superando los 10 000 casos notificados. Dada su naturaleza impredecible, este tipo de virus requiere métodos diagnósticos apropiados, confiables y seguros, pero que también estén al alcance de los laboratorios clínicos. Mediante el estudio de 291 muestras de pacientes con sospecha de infección por virus Influenza A(H1N1 en Neuquén, Argentina, el presente trabajo compara los dos métodos de diagnóstico utilizados simultáneamente: la prueba de inmunofluorescencia directa (DFA y la de reacción en cadena de la polimerasa en tiempo real (RT-PCR. La DFA dio una sensibilidad de 44,4%, especificidad de 99,6%, valor predictivo positivo de 95,2% y valor predictivo negativo de 90,7%. Los resultados positivos de la metodología pueden considerarse verdaderos positivos. Un resultado negativo no excluye la presencia del virus y la muestra debe examinarse mediante RT-PCR. Del total de 291 muestras, 45 resultaron positivas por RT-PCR y 21 por DFA.By 25 April 2009, less than one month after the first human with Influenza A(H1N1 virus was detected in Mexico, the disease had already spread to more than 40 countries, with over 10 000 cases reported. Due to its unpredictability, this type of virus requires appropriate, reliable, and safe diagnostic methods that are also accessible to clinical laboratories. Through the analysis of 291 samples taken from patients with suspected Influenza A(H1N1 virus infection in Neuquén, Argentina, this study compares the two diagnostic methods used simultaneously: direct immunofluorescence assay (DFA and real-time polymerase chain reaction (RT-PCR. DFA had a sensitivity of 44.4%, a specificity of 99.6%, a positive predictive value of 95.2%, and a negative predictive value of 90.7%. Positive results obtained with this method can be considered true

  19. Multiplex RT-PCR assay for differentiating European swine influenza virus subtypes H1N1, H1N2 and H3N2.

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    Chiapponi, Chiara; Moreno, Ana; Barbieri, Ilaria; Merenda, Marianna; Foni, Emanuela

    2012-09-01

    In Europe, three major swine influenza viral (SIV) subtypes (H1N1, H1N2 and H3N2) have been isolated in pigs. Developing a test that is able to detect and identify the subtype of the circulating strain rapidly during an outbreak of respiratory disease in the pig population is of essential importance. This study describes two multiplex RT-PCRs which distinguish the haemagglutinin (HA) gene and the neuraminidase (NA) gene of the three major subtypes of SIV circulating in Europe. The HA PCR was able to identify the lineage (avian or human) of the HA of H1 subtypes. The analytical sensitivity of the test, considered to be unique, was assessed using three reference viruses. The detection limit corresponded to 1×10(-1) TCID(50)/200μl for avian-like H1N1, 1×10(0) TCID(50)/200μl for human-like H1N2 and 1×10(1) TCID(50)/200μl for H3N2 SIV. The multiplex RT-PCR was first carried out on a collection of 70 isolated viruses showing 100% specificity and then on clinical samples, from which viruses had previously been isolated, resulting in an 89% positive specificity of the viral subtype. Finally, the test was able to identify the viral subtype correctly in 56% of influenza A positive samples, from which SIV had not been isolated previously. It was also possible to identify mixed viral infections and the circulation of a reassortant strain before performing genomic studies. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Antigen-specific H1N1 influenza antibody responses in acute respiratory tract infections and their relation to influenza infection and disease course.

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    Haran, John Patrick; Hoaglin, David C; Chen, Huaiqing; Boyer, Edward W; Lu, Shan

    2014-08-01

    Early antibody responses to influenza infection are important in both clearance of virus and fighting the disease. Acute influenza antibody titers directed toward H1-antigens and their relation to infection type and patient outcomes have not been well investigated. Using hemagglutination inhibition (HI) assays, we aimed to characterize the H1-specific antibody titers in patients with influenza infection or another respiratory infection before and after the H1N1-pandemic influenza outbreak. Among patients with acute influenza infection we related duration of illness, severity of symptoms, and need for hospitalization to antibody titers. There were 134 adult patients (average age 34.7) who presented to an urban academic emergency department (ED) from October through March during the 2008-2011 influenza seasons with symptoms of fever and a cough. Nasal aspirates were tested by viral culture, and peripheral blood serum was run in seven H1-subtype HI assays. Acutely infected influenza patients had markedly lower antibody titers for six of the seven pseudotype viruses. For the average over the seven titers (log units, base 2) their mean was 7.24 (95% CI 6.88, 7.61) compared with 8.60 (95% CI 8.27, 8.92) among patients who had a non-influenza respiratory illness, pinfection, titers of some antibodies correlated with severity of symptoms and with total duration of illness (pacute respiratory infections, lower concentrations of H1-influenza-specific antibodies were associated with influenza infection. Among influenza-infected patients, higher antibody titers were present in patients with a longer duration of illness and with higher severity-of-symptom scores. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. 2009 pandemic influenza A (H1N1 virus outbreak and response--Rwanda, October, 2009-May, 2010.

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    Justin Wane

    Full Text Available BACKGROUND: In October 2009, the first case of pandemic influenza A(H1N1pdm09 (pH1N1 was confirmed in Kigali, Rwanda and countrywide dissemination occurred within several weeks. We describe clinical and epidemiological characteristics of this epidemic. METHODS: From October 2009 through May 2010, we undertook epidemiologic investigations and response to pH1N1. Respiratory specimens were collected from all patients meeting the WHO case definition for pH1N1, which were tested using CDC's real time RT-PCR protocol at the Rwandan National Reference Laboratory (NRL. Following documented viral transmission in the community, testing focused on clinically severe and high-risk group suspect cases. RESULTS: From October 9, 2009 through May 31, 2010, NRL tested 2,045 specimens. In total, 26% (n = 532 of specimens tested influenza positive; of these 96% (n = 510 were influenza A and 4% (n = 22 were influenza B. Of cases testing influenza A positive, 96.8% (n = 494, 3% (n = 15, and 0.2% (n = 1 were A(H1N1pdm09, Seasonal A(H3 and Seasonal A(non-subtyped, respectively. Among laboratory-confirmed cases, 263 (53.2% were children <15 years and 275 (52% were female. In total, 58 (12% cases were hospitalized with mean duration of hospitalization of 5 days (Range: 2-15 days. All cases recovered and there were no deaths. Overall, 339 (68% confirmed cases received oseltamivir in any setting. Among all positive cases, 26.9% (143/532 were among groups known to be at high risk of influenza-associated complications, including age <5 years 23% (122/532, asthma 0.8% (4/532, cardiac disease 1.5% (8/532, pregnancy 0.6% (3/532, diabetes mellitus 0.4% (2/532, and chronic malnutrition 0.8% (4/532. CONCLUSIONS: Rwanda experienced a PH1N1 outbreak which was epidemiologically similar to PH1N1 outbreaks in the region. Unlike seasonal influenza, children <15 years were the most affected by pH1N1. Lessons learned from the outbreak response included the need to

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

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    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.

  3. An analysis of 332 fatalities infected with pandemic 2009 influenza A (H1N1 in Argentina.

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    Ana M Balanzat

    Full Text Available The apparent high number of deaths in Argentina during the 2009 pandemic led to concern that the influenza A H1N1pdm disease was different there. We report the characteristics and risk factors for influenza A H1N1pdm fatalities.We identified laboratory-confirmed influenza A H1N1pdm fatalities occurring during June-July 2009. Physicians abstracted data on age, sex, time of onset of illness, medical history, clinical presentation at admission, laboratory, treatment, and outcomes using standardize questionnaires. We explored the characteristics of fatalities according to their age and risk group.Of 332 influenza A H1N1pdm fatalities, 226 (68% were among persons aged <50 years. Acute respiratory failure was the leading cause of death. Of all cases, 249 (75% had at least one comorbidity as defined by Advisory Committee on Immunization Practices. Obesity was reported in 32% with data and chronic pulmonary disease in 28%. Among the 40 deaths in children aged <5 years, chronic pulmonary disease (42% and neonatal pathologies (35% were the most common co-morbidities. Twenty (6% fatalities were among pregnant or postpartum women of which only 47% had diagnosed co-morbidities. Only 13% of patients received antiviral treatment within 48 hours of symptom onset. None of children aged <5 years or the pregnant women received antivirals within 48 h of symptom onset. As the pandemic progressed, the time from symptom-onset to medical care and to antiviral treatment decreased significantly among case-patients who subsequently died (p<0.001.Persons with co-morbidities, pregnant and who received antivirals late were over-represented among influenza A H1N1pdm deaths in Argentina, though timeliness of antiviral treatment improved during the pandemic.

  4. Analysis of alcohol-based hand sanitizer delivery systems: efficacy of foam, gel, and wipes against influenza A (H1N1) virus on hands.

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    Larson, Elaine L; Cohen, Bevin; Baxter, Kathleen A

    2012-11-01

    Minimal research has been published evaluating the effectiveness of hand hygiene delivery systems (ie, rubs, foams, or wipes) at removing viruses from hands. The purposes of this study were to determine the effect of several alcohol-based hand sanitizers in removing influenza A (H1N1) virus, and to compare the effectiveness of foam, gel, and hand wipe products. Hands of 30 volunteers were inoculated with H1N1 and randomized to treatment with foam, gel, or hand wipe applied to half of each volunteer's finger pads. The log(10) count of each subject's treated and untreated finger pads were averaged. Log(10) reductions were calculated from these differences and averaged within treatment group. Between-treatment analysis compared changes from the untreated finger pads using analysis of covariance with treatment as a factor and the average log(10) untreated finger pads as the covariate. Log(10) counts on control finger pads were 2.7-5.3 log(10) of the 50% infectious dose for tissue culture (TCID(50)/0.1 mL) (mean, 3.8 ± 0.5 log(10) TCID(50)/0.1 mL), and treated finger pad counts for all test products were 0.5-1.9 log(10) TCID(50)/0.1 mL (mean, 0.53 ± 0.17 log(10) TCID(50)/0.1 mL). Treatments with all products resulted in a significant reduction in viral titers (>3 logs) at their respective exposure times that were statistically comparable. All 3 delivery systems (foam, gel, and wipe) produced significantly reduced viral counts on hands. Copyright © 2012 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  5. New Orf virus (Parapoxvirus recombinant expressing H5 hemagglutinin protects mice against H5N1 and H1N1 influenza A virus.

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    Jörg Rohde

    Full Text Available Previously we demonstrated the versatile utility of the Parapoxvirus Orf virus (ORFV as a vector platform for the development of potent recombinant vaccines. In this study we present the generation of new ORFV recombinants expressing the hemagglutinin (HA or nucleoprotein (NP of the highly pathogenic avian influenza virus (HPAIV H5N1. Correct foreign gene expression was examined in vitro by immunofluorescence, Western blotting and flow cytometry. The protective potential of both recombinants was evaluated in the mouse challenge model. Despite adequate expression of NP, the recombinant D1701-V-NPh5 completely failed to protect mice from lethal challenge. However, the H5 HA-expressing recombinant D1701-V-HAh5n mediated solid protection in a dose-dependent manner. Two intramuscular (i.m. injections of the HA-expressing recombinant protected all animals from lethal HPAIV infection without loss of body weight. Notably, the immunized mice resisted cross-clade H5N1 and heterologous H1N1 (strain PR8 influenza virus challenge. In vivo antibody-mediated depletion of CD4-positive and/or CD8-posititve T-cell subpopulations during immunization and/or challenge infection implicated the relevance of CD4-positive T-cells for induction of protective immunity by D1701-V-HAh5n, whereas the absence of CD8-positive T-cells did not significantly influence protection. In summary, this study validates the potential of the ORFV vectored vaccines also to combat HPAIV.

  6. Decreased serologic response in vaccinated military recruits during 2011 correspond to genetic drift in concurrent circulating pandemic A/H1N1 viruses.

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    Dennis J Faix

    Full Text Available Population-based febrile respiratory illness surveillance conducted by the Department of Defense contributes to an estimate of vaccine effectiveness. Between January and March 2011, 64 cases of 2009 A/H1N1 (pH1N1, including one fatality, were confirmed in immunized recruits at Fort Jackson, South Carolina, suggesting insufficient efficacy for the pH1N1 component of the live attenuated influenza vaccine (LAIV.To test serologic protection, serum samples were collected at least 30 days post-vaccination from recruits at Fort Jackson (LAIV, Parris Island (LAIV and trivalent inactivated vaccine [TIV] at Cape May, New Jersey (TIV and responses measured against pre-vaccination sera. A subset of 78 LAIV and 64 TIV sera pairs from recruits who reported neither influenza vaccination in the prior year nor fever during training were tested by microneutralization (MN and hemagglutination inhibition (HI assays. MN results demonstrated that seroconversion in paired sera was greater in those who received TIV versus LAIV (74% and 37%. Additionally, the fold change associated with TIV vaccination was significantly different between circulating (2011 versus the vaccine strain (2009 of pH1N1 viruses (ANOVA p value = 0.0006. HI analyses revealed similar trends. Surface plasmon resonance (SPR analysis revealed that the quantity, IgG/IgM ratios, and affinity of anti-HA antibodies were significantly greater in TIV vaccinees. Finally, sequence analysis of the HA1 gene in concurrent circulating 2011 pH1N1 isolates from Fort Jackson exhibited modest amino acid divergence from the vaccine strain.Among military recruits in 2011, serum antibody response differed by vaccine type (LAIV vs. TIV and pH1N1 virus year (2009 vs. 2011. We hypothesize that antigen drift in circulating pH1N1 viruses contributed to reduce vaccine effectiveness at Fort Jackson. Our findings have wider implications regarding vaccine protection from circulating pH1N1 viruses in 2011-2012.

  7. Enfermedad respiratoria grave en terapia intensiva durante la pandemia por el virus de influenza A (H1N1 2009

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    José Aquino-Esperanza

    2010-10-01

    Full Text Available Se describen pacientes hospitalizados en una unidad de terapia intensiva por enfermedad respiratoria aguda grave con características de influenza durante los primeros meses de la pandemia por influenza A(H1N1 2009 en la Argentina. Evaluamos datos clínicos, scores de gravedad, pruebas de laboratorio, microbiología y radiología torácica al ingreso, evolución y mortalidad hospitalaria, comparando pacientes con y sin confirmación de H1N1 por test de reacción de polimerasa en cadena, transcriptasa reversa (RT-PCR. Entre junio y julio de 2009 se internaron 31 pacientes adultos con una mediana de edad de 54 años (percentilo 25-75: 33-66. Presentaron test positivo para H1N1, 17 pacientes. Tenían al menos una condición concurrente 16 pacientes. La expresión radiográfica más frecuente fue infiltrados intersticio-alveolares bilaterales en 20 casos; 5 tenían consolidación lobar unilateral. La coinfección bacteriana (aislamiento de bacterias o IgM positiva para infecciones bacterianas, se demostró en 21 pacientes. Requirieron ventilación mecánica 23 pacientes y 18 desarrollaron síndrome de distrés respiratorio agudo (SDRA. La linfopenia y elevación de creatinina-fosfoquinasa fue frecuente (83% y 65%, respectivamente. Los 6 pacientes que murieron (19% eran mayores de 75 años o tenían cáncer o inmunodepresión. El tratamiento antiviral temprano (≤ 48 horas se asoció a menor necesidad de ventilación mecánica (54% vs. 89%; p: 0.043. No hubo diferencia significativa en las variables analizadas entre el grupo H1N1 positivo y el negativo, lo que sugiere tener igual enfoque terapéutico frente a una epidemia. La infección por H1N1 determinó falla respiratoria aguda y SDRA. La mortalidad ocurrió en pacientes añosos o con co-morbilidades graves.

  8. Seroprevalence of Antibodies to Pandemic (H1N1 2009 Influenza Virus Among Hospital Staff in a Medical Center in Taiwan

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    Yu-Jiun Chan

    2010-02-01

    Conclusion: The SPR of antibodies against the pandemic (H1N1 2009 virus in the hospital staff was higher than that in the general population, reflecting a higher contact risk. Prevaccination surveillance of the immune status of different risk groups may help to prioritize which groups should be vaccinated first.

  9. Efficacy of soap and water and alcohol-based hand-rub preparations against live H1N1 influenza virus on the hands of human volunteers.

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    Grayson, M Lindsay; Melvani, Sharmila; Druce, Julian; Barr, Ian G; Ballard, Susan A; Johnson, Paul D R; Mastorakos, Tasoula; Birch, Christopher

    2009-02-01

    Although pandemic and avian influenza are known to be transmitted via human hands, there are minimal data regarding the effectiveness of routine hand hygiene (HH) protocols against pandemic and avian influenza. Twenty vaccinated, antibody-positive health care workers had their hands contaminated with 1 mL of 10(7) tissue culture infectious dose (TCID)(50)/0.1 mL live human influenza A virus (H1N1; A/New Caledonia/20/99) before undertaking 1 of 5 HH protocols (no HH [control], soap and water hand washing [SW], or use of 1 of 3 alcohol-based hand rubs [61.5% ethanol gel, 70% ethanol plus 0.5% chlorhexidine solution, or 70% isopropanol plus 0.5% chlorhexidine solution]). H1N1 concentrations were assessed before and after each intervention by viral culture and real-time reverse-transcriptase polymerase chain reaction (PCR). The natural viability of H1N1 on hands for >60 min without HH was also assessed. There was an immediate reduction in culture-detectable and PCR-detectable H1N1 after brief cutaneous air drying--14 of 20 health care workers had H1N1 detected by means of culture (mean reduction, 10(3-4) TCID(50)/0.1 mL), whereas 6 of 20 had no viable H1N1 recovered; all 20 health care workers had similar changes in PCR test results. Marked antiviral efficacy was noted for all 4 HH protocols, on the basis of culture results (14 of 14 had no culturable H1N1; (P< .002) and PCR results (P< .001; cycle threshold value range, 33.3-39.4), with SW statistically superior (P< .001) to all 3 alcohol-based hand rubs, although the actual difference was only 1-100 virus copies/microL. There was minimal reduction in H1N1 after 60 min without HH. HH with SW or alcohol-based hand rub is highly effective in reducing influenza A virus on human hands, although SW is the most effective intervention. Appropriate HH may be an important public health initiative to reduce pandemic and avian influenza transmission.

  10. Antibody Persistence in Adults Two Years after Vaccination with an H1N1 2009 Pandemic Influenza Virus-Like Particle Vaccine.

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    Nuriban Valero-Pacheco

    Full Text Available The influenza virus is a human pathogen that causes epidemics every year, as well as potential pandemic outbreaks, as occurred in 2009. Vaccination has proven to be sufficient in the prevention and containment of viral spreading. In addition to the current egg-based vaccines, new and promising vaccine platforms, such as cell culture-derived vaccines that include virus-like particles (VLPs, have been developed. VLPs have been shown to be both safe and immunogenic against influenza infections. Although antibody persistence has been studied in traditional egg-based influenza vaccines, studies on antibody response durations induced by VLP influenza vaccines in humans are scarce. Here, we show that subjects vaccinated with an insect cell-derived VLP vaccine, in the midst of the 2009 H1N1 influenza pandemic outbreak in Mexico City, showed antibody persistence up to 24 months post-vaccination. Additionally, we found that subjects that reported being revaccinated with a subsequent inactivated influenza virus vaccine showed higher antibody titres to the pandemic influenza virus than those who were not revaccinated. These findings provide insights into the duration of the antibody responses elicited by an insect cell-derived pandemic influenza VLP vaccine and the possible effects of subsequent influenza vaccination on antibody persistence induced by this VLP vaccine in humans.

  11. The immuno-regulatory impact of orally-administered Hypericum perforatum extract on Balb/C mice inoculated with H1n1 influenza A virus.

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    Nan Huang

    Full Text Available Hypericumperforatum (H. perforatum ethanol extract has been found to inhibit lipopolysaccharide-induced production of inflammatory mediators and cytokines in cultured macrophages. Therefore, it may be able to protect the host from excessive inflammation during viral infection. In the current study, the immune-regulatory effect of H. perforatum extract was evaluated in A549 lung epithelial cells and BALB/c mice exposed to Influenza A/PR/8/34 H1N1 virus. In A549 cells, the extract (30 µg/mL significantly inhibited influenza virus induced monocyte chemotactic protein (MCP-1 and interferon-γ induced protein 10 kD (IP-10, but dramatically increased interleukin-6 (IL-6. In mice inoculated intranasally with 10(7.9 EID50 of Influenza A/PR/8/34 H1N1 (high dose, daily oral treatment of H. perforatum extract at a rate of 110 mg/kg of body weight increased lung viral titer, bronchoalveolar lavage (BAL pro-inflammatory cytokine and chemokine levels, and the infiltration of pro-inflammatory cells in the lung 5 days post-inoculation, as compared to ethanol vehicle treated mice. Transcription of suppressor of cytokine signaling 3 (SOCS3 was increased by H. perforatum extract both in A549 cells and BALB/c mice, which could have interrupted anti-viral immune response and thus led to the inefficient viral clearance and increased lung inflammation. H. perforatum treatment resulted in minor reduction in viral titer without affecting body weight when mice were inoculated with a lower dose (~10(5.0 EID50 and H. perforatum was applied in the later phase of infection. Mice challenged intranasally with high dose of influenza virus (10(7.9 EID50 suffered from a higher mortality rate when dosed with H. perforatum extract. In conclusion, the current study showed that SOCS3 elevation by H. perforatum may cause impaired immune defense against influenza virus infection and lead to higher mortality.

  12. Secondary household transmission of 2009 pandemic influenza A (H1N1 virus among an urban and rural population in Kenya, 2009-2010.

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    Clara Y Kim

    Full Text Available BACKGROUND: In Kenya, >1,200 laboratory-confirmed 2009 pandemic influenza A (H1N1 (pH1N1 cases occurred since June 2009. We used population-based infectious disease surveillance (PBIDS data to assess household transmission of pH1N1 in urban Nairobi (Kibera and rural Lwak. METHODS: We defined a pH1N1 patient as laboratory-confirmed pH1N1 infection among PBIDS participants during August 1, 2009-February 5, 2010, in Kibera, or August 1, 2009-January 20, 2010, in Lwak, and a case household as a household with a laboratory-confirmed pH1N1 patient. Community interviewers visited PBIDS-participating households to inquire about illnesses among household members. We randomly selected 4 comparison households per case household matched by number of children aged <5. Comparison households had a household visit 10 days before or after the matched patient symptom onset date. We defined influenza-like illnesses (ILI as self-reported cough or sore throat, and a self-reported fever ≤8 days after the pH1N1 patient's symptom onset in case households and ≤8 days before selected household visit in comparison households. We used the Cochran-Mantel-Haenszel test to compare proportions of ILIs among case and comparison households, and log binomial-model to compare that of Kibera and Lwak. RESULTS: Among household contacts of patients with confirmed pH1N1 in Kibera, 4.6% had ILI compared with 8.2% in Lwak (risk ratio [RR], 0.5; 95% confidence interval [CI], 0.3-0.9. Household contacts of patients were more likely to have ILIs than comparison-household members in both Kibera (RR, 1.8; 95% CI, 1.1-2.8 and Lwak (RR, 2.6; 95% CI, 1.6-4.3. Overall, ILI was not associated with patient age. However, ILI rates among household contacts were higher among children aged <5 years than persons aged ≥5 years in Lwak, but not Kibera. CONCLUSIONS: Substantial pH1N1 household transmission occurred in urban and rural Kenya. Household transmission rates were higher in the rural area.

  13. Characterization of functional antibody and memory B-cell responses to pH1N1 monovalent vaccine in HIV-infected children and youth.

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    Donna J Curtis

    Full Text Available We investigated immune determinants of antibody responses and B-cell memory to pH1N1 vaccine in HIV-infected children.Ninety subjects 4 to <25 years of age received two double doses of pH1N1 vaccine. Serum and cells were frozen at baseline, after each vaccination, and at 28 weeks post-immunization. Hemagglutination inhibition (HAI titers, avidity indices (AI, B-cell subsets, and pH1N1 IgG and IgA antigen secreting cells (ASC were measured at baseline and after each vaccination. Neutralizing antibodies and pH1N1-specific Th1, Th2 and Tfh cytokines were measured at baseline and post-dose 1.At entry, 26 (29% subjects had pH1N1 protective HAI titers (≥1:40. pH1N1-specific HAI, neutralizing titers, AI, IgG ASC, IL-2 and IL-4 increased in response to vaccination (p<0.05, but IgA ASC, IL-5, IL-13, IL-21, IFNγ and B-cell subsets did not change. Subjects with baseline HAI ≥1:40 had significantly greater increases in IgG ASC and AI after immunization compared with those with HAI <1:40. Neutralizing titers and AI after vaccination increased with older age. High pH1N1 HAI responses were associated with increased IgG ASC, IFNγ, IL-2, microneutralizion titers, and AI. Microneutralization titers after vaccination increased with high IgG ASC and IL-2 responses. IgG ASC also increased with high IFNγ responses. CD4% and viral load did not predict the immune responses post-vaccination, but the B-cell distribution did. Notably, vaccine immunogenicity increased with high CD19+CD21+CD27+% resting memory, high CD19+CD10+CD27+% immature activated, low CD19+CD21-CD27-CD20-% tissue-like, low CD19+CD21-CD27-CD20-% transitional and low CD19+CD38+HLADR+% activated B-cell subsets.HIV-infected children on HAART mount a broad B-cell memory response to pH1N1 vaccine, which was higher for subjects with baseline HAI≥1:40 and increased with age, presumably due to prior exposure to pH1N1 or to other influenza vaccination/infection. The response to the vaccine was dependent

  14. Whole Genome Characterization, Phylogenetic and Genome Signature Analysis of Human Pandemic H1N1 Virus in Thailand, 2009–2012

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    Makkoch, Jarika; Suwannakarn, Kamol; Payungporn, Sunchai; Prachayangprecha, Slinporn; Cheiocharnsin, Thaweesak; Linsuwanon, Piyada; Theamboonlers, Apiradee; Poovorawan, Yong

    2012-01-01

    Background Three waves of human pandemic influenza occurred in Thailand in 2009–2012. The genome signature features and evolution of pH1N1 need to be characterized to elucidate the aspects responsible for the multiple waves of pandemic. Methodology/Findings Forty whole genome sequences and 584 partial sequences of pH1N1 circulating in Thailand, divided into 1st, 2nd and 3rd wave and post-pandemic were characterized and 77 genome signatures were analyzed. Phylogenetic trees of concatenated whole genome and HA gene sequences were constructed calculating substitution rate and dN/dS of each gene. Phylogenetic analysis showed a distinct pattern of pH1N1 circulation in Thailand, with the first two isolates from May, 2009 belonging to clade 5 while clades 5, 6 and 7 co-circulated during the first wave of pH1N1 pandemic in Thailand. Clade 8 predominated during the second wave and different proportions of the pH1N1 viruses circulating during the third wave and post pandemic period belonged to clades 8, 11.1 and 11.2. The mutation analysis of pH1N1 revealed many adaptive mutations which have become the signature of each clade and may be responsible for the multiple pandemic waves in Thailand, especially with regard to clades 11.1 and 11.2 as evidenced with V731I, G154D of PB1 gene, PA I330V, HA A214T S160G and S202T. The substitution rate of pH1N1 in Thailand ranged from 2.53×10−3±0.02 (M2 genes) to 5.27×10−3±0.03 per site per year (NA gene). Conclusions All results suggested that this virus is still adaptive, maybe to evade the host's immune response and tends to remain in the human host although the dN/dS were under purifying selection in all 8 genes. Due to the gradual evolution of pH1N1 in Thailand, continuous monitoring is essential for evaluation and surveillance to be prepared for and able to control future influenza activities. PMID:23251479

  15. Differential host determinants contribute to the pathogenesis of 2009 pandemic H1N1 and human H5N1 influenza A viruses in experimental mouse models.

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    Otte, Anna; Sauter, Martina; Alleva, Lisa; Baumgarte, Sigrid; Klingel, Karin; Gabriel, Gülsah

    2011-07-01

    Influenza viruses are responsible for high morbidities in humans and may, eventually, cause pandemics. Herein, we compared the pathogenesis and host innate immune responses of a seasonal H1N1, two 2009 pandemic H1N1, and a human H5N1 influenza virus in experimental BALB/c and C57BL/6J mouse models. We found that both 2009 pandemic H1N1 isolates studied (A/Hamburg/05/09 and A/Hamburg/NY1580/09) were low pathogenic in BALB/c mice [log mouse lethal dose 50 (MLD(50)) >6 plaque-forming units (PFU)] but displayed remarkable differences in virulence in C57BL/6J mice. A/Hamburg/NY1580/09 was more virulent (logMLD(50) = 3.5 PFU) than A/Hamburg/05/09 (logMLD(50) = 5.2 PFU) in C57BL/6J mice. In contrast, the H5N1 influenza virus was more virulent in BALB/c mice (logMLD(50) = 0.3 PFU) than in C57BL/6J mice (logMLD(50) = 1.8 PFU). Seasonal H1N1 influenza revealed marginal pathogenicity in BALB/c or C57BL/6J mice (logMLD(50) >6 PFU). Enhanced susceptibility of C57BL/6J mice to pandemic H1N1 correlated with a depressed cytokine response. In contrast, enhanced H5N1 virulence in BALB/c mice correlated with an elevated proinflammatory cytokine response. These findings highlight that host determinants responsible for the pathogenesis of 2009 pandemic H1N1 influenza viruses are different from those contributing to H5N1 pathogenesis. Our results show, for the first time to our knowledge, that the C57BL/6J mouse strain is more appropriate for the evaluation and identification of intrinsic pathogenicity markers of 2009 pandemic H1N1 influenza viruses that are "masked" in BALB/c mice. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  16. Likely Correlation between Sources of Information and Acceptability of A/H1N1 Swine-Origin Influenza Virus Vaccine in Marseille, France

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    Ninove, Laetitia; Sartor, Catherine; Badiaga, Sékéné; Botelho, Elizabeth; Brouqui, Philippe; Zandotti, Christine; De Lamballerie, Xavier; La Scola, Bernard; Drancourt, Michel; Gould, Ernest A.; Charrel, Rémi N.; Raoult, Didier

    2010-01-01

    Background In France, there was a reluctance to accept vaccination against the A/H1N1 pandemic influenza virus despite government recommendation and investment in the vaccine programme. Methods and Findings We examined the willingness of different populations to accept A/H1N1vaccination (i) in a French hospital among 3315 employees immunized either by in-house medical personnel or mobile teams of MDs and (ii) in a shelter housing 250 homeless persons. Google was used to assess the volume of enquiries concerning incidence of influenza. We analyzed the information on vaccination provided by Google, the website of the major French newspapers, and PubMed. Two trust Surveys were used to assess public opinion on the trustworthiness of people in different professions. Paramedics were significantly more reluctant to accept immunisation than qualified medical staff. Acceptance was significantly increased when recommended directly by MDs. Anecdotal cases of directly observed severe infections were followed by enhanced acceptance of paramedical staff. Scientific literature was significantly more in favour of vaccination than Google and French newspaper websites. In the case of the newspaper websites, information correlated with their recognised political reputations, although they would presumably claim independence from political bias. The Trust Surveys showed that politicians were highly distrusted in contrast with doctors and pharmacists who were considered much more trustworthy. Conclusions The low uptake of the vaccine could reflect failure to convey high quality medical information and advice relating to the benefits of being vaccinated. We believe that the media and internet contributed to this problem by raising concerns within the general population and that failure to involve GPs in the control programme may have been a mistake. GPs are highly regarded by the public and can provide face-to-face professional advice and information. The top-down strategy of vaccine

  17. Broadly-reactive human monoclonal antibodies elicited following pandemic H1N1 influenza virus exposure protect mice from highly pathogenic H5N1 challenge.

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    Nachbagauer, Raffael; Shore, David; Yang, Hua; Johnson, Scott K; Gabbard, Jon D; Tompkins, S Mark; Wrammert, Jens; Wilson, Patrick C; Stevens, James; Ahmed, Rafi; Krammer, Florian; Ellebedy, Ali H

    2018-06-13

    Broadly cross-reactive antibodies that recognize conserved epitopes within the influenza virus hemagglutinin (HA) stalk domain are of particular interest for their potential use as therapeutic and prophylactic agents against multiple influenza virus subtypes including zoonotic virus strains. Here, we characterized four human HA stalk-reactive monoclonal antibodies (mAbs) for their binding breadth and affinity, in vitro neutralization capacity, and in vivo protective potential against an highly pathogenic avian influenza virus. The monoclonal antibodies were isolated from individuals shortly following infection with (70-1F02 and 1009-3B05) or vaccination against (05-2G02 and 09-3A01) A(H1N1)pdm09. Three of the mAbs bound HAs from multiple strains of group 1 viruses, and one mAb, 05-2G02, bound to both group 1 and group 2 influenza A HAs. All four antibodies prophylactically protected mice against a lethal challenge with the highly pathogenic A/Vietnam/1203/04 (H5N1) strain. Two mAbs, 70-1F02 and 09-3A01, were further tested for their therapeutic efficacy against the same strain and showed good efficacy in this setting as well. One mAb, 70-1F02, was co-crystallized with H5 HA and showed similar heavy chain only interactions as a the previously described anti-stalk antibody CR6261. Finally, we showed that antibodies that compete with these mAbs are prevalent in serum from an individual recently infected with A(H1N1)pdm09 virus. The antibodies described here can be developed into broad-spectrum antiviral therapeutics that could be used to combat infections with zoonotic or emerging pandemic influenza viruses. IMPORTANCE The rise in zoonotic infections of humans with emerging influenza viruses is a worldwide public health concern. The majority of recent zoonotic human influenza cases were caused by H7N9 and H5Nx viruses and were associated with high morbidity and mortality. In addition, seasonal influenza viruses are estimated to cause up to 650,000 deaths annually

  18. Protection of guinea pigs by vaccination with a recombinant swinepox virus co-expressing HA1 genes of swine H1N1 and H3N2 influenza viruses.

    Science.gov (United States)

    Xu, Jiarong; Yang, Deji; Huang, Dongyan; Xu, Jiaping; Liu, Shichao; Lin, Huixing; Zhu, Haodan; Liu, Bao; Lu, Chengping

    2013-03-01

    Swine influenza (SI) is an acute respiratory infectious disease of swine caused by swine influenza virus (SIV). SIV is not only an important respiratory pathogen in pigs but also a potent threat to human health. Here, we report the construction of a recombinant swinepox virus (rSPV/H3-2A-H1) co-expressing hemagglutinin (HA1) of SIV subtypes H1N1 and H3N2. Immune responses and protection efficacy of the rSPV/H3-2A-H1 were evaluated in guinea pigs. Inoculation of rSPV/H3-2A-H1 yielded neutralizing antibodies against SIV H1N1 and H3N2. The IFN-γ and IL-4 concentrations in the supernatant of lymphocytes stimulated with purified SIV HA1 antigen were significantly higher (P guinea pigs against SIV H1N1 or H3N2 challenge was observed. No SIV shedding was detected from guinea pigs vaccinated with rSPV/H3-2A-H1 after challenge. Most importantly, the guinea pigs immunized with rSPV/H3-2A-H1 did not show gross and micrographic lung lesions. However, the control guinea pigs experienced distinct gross and micrographic lung lesions at 7 days post-challenge. Our data suggest that the recombinant swinepox virus encoding HA1 of SIV H1N1 and H3N2 might serve as a promising candidate vaccine for protection against SIV H1N1 and H3N2 infections.

  19. [Effect and mechanism of Mahuang Tang against influenza A/H1N1 virus in vitro].

    Science.gov (United States)

    Wei, Wen-Yang; Wan, Hai-Tong; Yu, Li; Lu, Yi-Yu; He, Yu

    2018-02-01

    To study the effect and underlying mechanism of Mahuang Tang against influenza A virus in vitro , the influenza virus-infected Madin-Darby canine kidney(MDCK) cells were used as the carrier in this study to detect the median tissue culture-infective dose(TCID₅₀) of influenza A virus strains(A/PR8/34) on MDCK cells with cytopathic effect(CPE) assay. Blocking influenza virus invading host cells and anti-influenza virus biosynthesis were used as two different administration methods, and then the methyl thiazolyl tetrazolium(MTT) assay was utilized to determine the antiviral effective rate(ER), median efficacious concentration(EC₅₀) and therapeutic index(TI) of Mahuang Tang. The quantitative Real-time polymerase chain reaction(RT-PCR) was used to measure virus load and the mRNA expression levels of TLR4, TLR7, MyD88 and TRAF6 in MDCK cells at 24, 48 h after the treatment. The experiment results indicated that TCID₅₀ of A/PR8/34 for MDCK cells was 1×10-4.32/mL. The EC₅₀ values of two different treatment methods were 4.92,1.59 g·L⁻¹ respectively, the TI values were 12.53, 38.78 respectively, and when the concentration of Mahuang Tang was 5.00 g·L⁻¹, ER values were 50.21%, 98.41% respectively, showing that Mahuang Tang can block influenza virus into the host cells and significantly inhibit their biosynthesis. Meanwhile, as compared with the virus group, the virus load was significantly inhibited in Mahuang Tang groups, and Mahuang Tang high and middle doses had the significant effect on decreasing the mRNA expression of TLR4, TLR7,MyD88 and TRAF6 at 24, 48 h after the treatment. It can be demonstrated that the mechanisms of Mahuang Tang against influenza A virus are related to the inhibition of influenza virus replication and the mRNA expression of correlative genes in TLR4 and TLR7 signaling pathways. Copyright© by the Chinese Pharmaceutical Association.

  20. Genetic and biological characterisation of an avian-like H1N2 swine influenza virus generated by reassortment of circulating avian-like H1N1 and H3N2 subtypes in Denmark

    DEFF Research Database (Denmark)

    Trebbien, Ramona; Bragstad, Karoline; Larsen, Lars Erik

    2013-01-01

    BACKGROUND: The influenza A virus subtypes H1N1, H1N2 and H3N2 are the most prevalent subtypes in swine. In 2003, a reassorted H1N2 swine influenza virus (SIV) subtype appeared and became prevalent in Denmark. In the present study, the reassortant H1N2 subtype was characterised genetically...... and the infection dynamics compared to an “avian-like” H1N1 virus by an experimental infection study. METHODS: Sequence analyses were performed of the H1N2 virus. Two groups of pigs were inoculated with the reassortant H1N2 virus and an “avian-like” H1N1 virus, respectively, followed by inoculation...... with the opposite subtype four weeks later. Measurements of HI antibodies and acute phase proteins were performed. Nasal virus excretion and virus load in lungs were determined by real-time RT-PCR. RESULTS: The phylogenetic analysis revealed that the reassorted H1N2 virus contained a European “avian-like” H1-gene...

  1. Filament-producing mutants of influenza A/Puerto Rico/8/1934 (H1N1 virus have higher neuraminidase activities than the spherical wild-type.

    Directory of Open Access Journals (Sweden)

    Jill Seladi-Schulman

    Full Text Available Influenza virus exhibits two morphologies - spherical and filamentous. Strains that have been grown extensively in laboratory substrates are comprised predominantly of spherical virions while clinical or low passage isolates produce a mixture of spheres and filamentous virions of varying lengths. The filamentous morphology can be lost upon continued passage in embryonated chicken eggs, a common laboratory substrate for influenza viruses. The fact that the filamentous morphology is maintained in nature but lost in favor of a spherical morphology in ovo suggests that filaments confer a selective advantage within the infected host that is not necessary for growth in laboratory substrates. Indeed, we have recently shown that filament-producing variant viruses are selected upon passage of the spherical laboratory strain A/Puerto Rico/8/1934 (H1N1 [PR8] in guinea pigs. Toward determining the nature of the selective advantage conferred by filaments, we sought to identify functional differences between spherical and filamentous particles. We compared the wild-type PR8 virus to two previously characterized recombinant PR8 viruses in which single point mutations within M1 confer a filamentous morphology. Our results indicate that these filamentous PR8 mutants have higher neuraminidase activities than the spherical PR8 virus. Conversely, no differences were observed in HAU:PFU or HAU:RNA ratios, binding avidity, sensitivity to immune serum in hemagglutination inhibition assays, or virion stability at elevated temperatures. Based on these results, we propose that the pleomorphic nature of influenza virus particles is important for the optimization of neuraminidase functions in vivo.

  2. Characterization of a newly emerged genetic cluster of H1N1 and H1N2 swine influenza virus in the United States.

    Science.gov (United States)

    Vincent, Amy L; Ma, Wenjun; Lager, Kelly M; Gramer, Marie R; Richt, Juergen A; Janke, Bruce H

    2009-10-01

    H1 influenza A viruses that were distinct from the classical swine H1 lineage were identified in pigs in Canada in 2003–2004; antigenic and genetic characterization identified the hemagglutinin (HA) as human H1 lineage. The viruses identified in Canadian pigs were human lineage in entirety or double (human–swine) reassortants. Here, we report the whole genome sequence analysis of four human-like H1 viruses isolated from U.S. swine in 2005 and 2007. All four isolates were characterized as triple reassortants with an internal gene constellation similar to contemporary U.S. swine influenza virus (SIV), with HA and neuraminidase (NA) most similar to human influenza virus lineages. A 2007 human-like H1N1 was evaluated in a pathogenesis and transmission model and compared to a 2004 reassortant H1N1 SIV isolate with swine lineage HA and NA. The 2007 isolate induced disease typical of influenza virus and was transmitted to contact pigs; however, the kinetics and magnitude differed from the 2004 H1N1 SIV. This study indicates that the human-like H1 SIV can efficiently replicate and transmit in the swine host and now co-circulates with contemporary SIVs as a distinct genetic cluster of H1 SIV.

  3. Punctuated Evolution of Influenza Virus Neuraminidase (A/H1N1 under Opposing Migration and Vaccination Pressures

    Directory of Open Access Journals (Sweden)

    J. C. Phillips

    2014-01-01

    Full Text Available Influenza virus contains two highly variable envelope glycoproteins, hemagglutinin (HA and neuraminidase (NA. The structure and properties of HA, which is responsible for binding the virus to the cell that is being infected, change significantly when the virus is transmitted from avian or swine species to humans. Here we focus first on the simpler problem of the much smaller human individual evolutionary amino acid mutational changes in NA, which cleaves sialic acid groups and is required for influenza virus replication. Our thermodynamic panorama shows that very small amino acid changes can be monitored very accurately across many historic (1945–2011 Uniprot and NCBI strains using hydropathicity scales to quantify the roughness of water film packages. Quantitative sequential analysis is most effective with the fractal differential hydropathicity scale based on protein self-organized criticality (SOC. Our analysis shows that large-scale vaccination programs have been responsible for a very large convergent reduction in common influenza severity in the last century. Hydropathic analysis is capable of interpreting and even predicting trends of functional changes in mutation prolific viruses directly from amino acid sequences alone. An engineered strain of NA1 is described which could well be significantly less virulent than current circulating strains.

  4. Acceptance of a vaccine against novel influenza A (H1N1) virus among health care workers in two major cities in Mexico.

    Science.gov (United States)

    Esteves-Jaramillo, Alejandra; Omer, Saad B; Gonzalez-Diaz, Esteban; Salmon, Daniel A; Hixson, Brooke; Navarro, Francisco; Kawa-Karasik, Simon; Frew, Paula; Morfin-Otero, Rayo; Rodriguez-Noriega, Eduardo; Ramirez, Ylean; Rosas, Araceli; Acosta, Edgar; Varela-Badillo, Vianey; Del Rio, Carlos

    2009-11-01

    Further cases of novel influenza A (H1N1) outbreak are expected in the coming months. Vaccination has been proven to be essential to control a pandemic of influenza; therefore, considerable efforts and resources have been devoted to develop a vaccine against the influenza A (H1N1) virus. With the current availability of the vaccine, it will be important to immunize as many people as possible. However, previous data with seasonal influenza vaccines have shown that there are multiple barriers related to perceptions and attitudes of the population that influence vaccine use. The aim of the study was to evaluate the acceptance of a newly developed vaccine against pandemic (H1N1) 2009 influenza A among healthcare workers (HCW) in Mexico. We conducted a cross-sectional study among HCW in three hospitals in the two largest cities in Mexico-Mexico City and Guadalajara-between June and September 2009. A total of 1097 HCW participated in the survey. Overall, 80% (n = 880) intended to accept the H1N1 pandemic vaccine and 71.6% (n = 786) reported they would recommend the vaccine to their patients. Doctors were more likely to accept and recommend the vaccine than nurses. HCWs who intend to be immunized will be more likely to do so if they know that the vaccine is safe and effective. Knowledge of the willingness to accept the vaccine can be used to plan strategies that will effectively respond to the needs of the population studied, reducing the health and economic impact of novel influenza A (H1N1) virus.

  5. Evaluation of twenty rapid antigen tests for the detection of human influenza A H5N1, H3N2, H1N1, and B viruses.

    Science.gov (United States)

    Taylor, Janette; McPhie, Kenneth; Druce, Julian; Birch, Chris; Dwyer, Dominic E

    2009-11-01

    Twenty rapid antigen assays were compared for their ability to detect influenza using dilutions of virus culture supernatants from human isolates of influenza A H5N1 (clade 1 and 2 strains), H3N2 and H1N1 viruses, and influenza B. There was variation amongst the rapid antigen assays in their ability to detect different influenza viruses. Six of the 12 assays labeled as distinguishing between influenza A and B had comparable analytical sensitivities for detecting both influenza A H5N1 strains, although their ability to detect influenza A H3N2 and H1N1 strains varied. The two assays claiming H5 specificity did not detect either influenza A H5N1 strains, and the two avian influenza-specific assays detected influenza A H5N1, but missed some influenza A H3N2 virus supernatants. Clinical trials of rapid antigen tests for influenza A H5N1 are limited. For use in a pandemic where novel influenza strains are circulating (such as the current novel influenza A H1N1 09 virus), rapid antigen tests should ideally have comparable sensitivity and specificity for the new strains as for co-circulating seasonal influenza strains.

  6. Computational Identification of Antigenicity-Associated Sites in the Hemagglutinin Protein of A/H1N1 Seasonal Influenza Virus.

    Directory of Open Access Journals (Sweden)

    Xiaowei Ren

    Full Text Available The antigenic variability of influenza viruses has always made influenza vaccine development challenging. The punctuated nature of antigenic drift of influenza virus suggests that a relatively small number of genetic changes or combinations of genetic changes may drive changes in antigenic phenotype. The present study aimed to identify antigenicity-associated sites in the hemagglutinin protein of A/H1N1 seasonal influenza virus using computational approaches. Random Forest Regression (RFR and Support Vector Regression based on Recursive Feature Elimination (SVR-RFE were applied to H1N1 seasonal influenza viruses and used to analyze the associations between amino acid changes in the HA1 polypeptide and antigenic variation based on hemagglutination-inhibition (HI assay data. Twenty-three and twenty antigenicity-associated sites were identified by RFR and SVR-RFE, respectively, by considering the joint effects of amino acid residues on antigenic drift. Our proposed approaches were further validated with the H3N2 dataset. The prediction models developed in this study can quantitatively predict antigenic differences with high prediction accuracy based only on HA1 sequences. Application of the study results can increase understanding of H1N1 seasonal influenza virus antigenic evolution and accelerate the selection of vaccine strains.

  7. Crystallization and X-ray crystallographic analysis of the cap-binding domain of influenza A virus H1N1 polymerase subunit PB2

    International Nuclear Information System (INIS)

    Liu, Yong; Meng, Geng; Luo, Ming; Zheng, Xiaofeng

    2013-01-01

    Substrate-free cap-binding domain of influenza A virus H1N1 polymerase subunit PB2 has been crystallized to show the structural details and clarify whether obvious conformational changes exist between the substrate-free and substrate-bound cap-binding domain. PB2 is one of the subunits of the influenza virus heterotrimeric polymerase. By its cap-binding domain (PB2 cap ), PB2 captures the 5′ cap of the host pre-mRNA to generate a capped 5′ oligonucleotide primer for virus transcription. The crystal structure of influenza A virus H3N2 PB2 cap with bound cap analogue m 7 GTP has been reported previously. To show the substrate-free structural details of PB2 cap and clarify whether obvious conformational changes exist between the substrate-free and substrate-bound cap-binding domain, we have successfully obtained the crystal of substrate-free H1N1 PB2 cap . The crystal of H1N1 PB2 cap diffracted to a high resolution of 1.32 Å. The crystal symmetry belongs to space group P1 with unit-cell parameters a = 29.49, b = 37.04, c = 38.33 Å, α = 71.10, β = 69.84, γ = 75.85°. There is one molecule in the asymmetric unit

  8. High Level Antibody Response to Pandemic Influenza H1N1/09 Virus Is Associated With Interferon-Induced Transmembrane Protein-3 rs12252-CC in Young Adults

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    Ling Qin

    2018-05-01

    Full Text Available Background: The C allele of the interferon-induced transmembrane protein-3 (IFITM3 SNP rs12252, a common allele in South East Asia and China, is strongly associated with severe influenza infection. However, despite the high occurrence of rs12252-CC genotype in Chinese population (~25%, severe influenza infection is rare. The aim of study is to determine whether rs12252-CC individuals have pre-existing antibody responses to previous seasonal influenza infections.Cohort and Method: A total 99 young healthy volunteers (18–20 years were recruited and received an influenza seasonal Vaccination [A/Switzerland/9715293/2013(H3N2, A/California/7/2009 (pdm09H1N1 and B/Jeep/3073/2013-like virus (Flu-B]. Plasma and gDNA was isolated from each volunteer before, and 14, 28, 180, 360, and 540 days after vaccination. Additionally, 68 elderlies (>65 years were also recruited as a control group to compare the levels of antibodies at baseline between the young adults and the elderly. For each sample IFITM3 rs12252 genotype was determined and antibody levels in response to pdmH1N1, H3N2 and Influenza B infection were measured for each time point.Results: We found a significantly higher level of pre-existing antibodies to pandemic influenza H1N1/09 virus (pdm09H1N1 but not to H3N2 or FluB in CC donors in comparison with CT/TT donors prior to vaccination. No impact of IFITM3 genotype in boosting influenza specific antibodies in young adults within 1 year after receiving seasonal influenza vaccination was observed. In addition, there was no difference in pdm09H1N1 specific antibody levels observed in the elderly cohort between volunteers carrying different IFITM3 genotypes. Higher levels of antibodies to pdmH1N1 were observed in elderly CC carriers when compared to the young CC carriers, but this trend was not replicated in TT carriers.Conclusion:IFITM3-rs12252 CC carriers exhibit a high level of pre-existing immunity to pdm09H1N1 compared to TT carriers in the

  9. Seroprevalence of H1N1, H3N2 and H1N2 influenza viruses in pigs in seven European countries in 2002-2003

    NARCIS (Netherlands)

    Reeth, K.; Brown, I.H.; Durrwald, R.; Foni, E.; Labarque, G.; Lenihan, P.; Maldonado, J.; Markowska-Daniel, I.; Pensaert, M.; Pospisil, Z.; Koch, G.

    2008-01-01

    Objectives Avian-like H1N1 and human-like H3N2 swine influenza viruses (SIV) have been considered widespread among pigs in Western Europe since the 1980s, and a novel H1N2 reassortant with a human-like H1 emerged in the mid 1990s. This study, which was part of the EC-funded 'European Surveillance

  10. Sales of oseltamivir in Norway prior to the emergence of oseltamivir resistant influenza A(H1N1 viruses in 2007–08

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    Hungnes Olav

    2009-05-01

    Full Text Available Abstract Background An unprecedented high proportion of oseltamivir resistant influenza A(H1N1 viruses emerged in the 2007–08 influenza season. In Norway, two thirds of all tested A(H1N1 viruses were resistant to the antiviral drug. In order to see if this emergence could be explained by a drug induced selection pressure, we analysed data on the sales of oseltamivir in Norway for the years 2002–07. Methods We used data from two sources; the Norwegian Drug Wholesales Statistics Database and the Norwegian Prescription Database (NorPD, for the years 2002–2007. We calculated courses sold of oseltamivir (Tamiflu® per 1000 inhabitants per year. Results Our data showed that, except for the years 2005 and 2006, sales of oseltamivir were low in Norway; courses sold per 1000 inhabitants varied between 0.17–1.64. The higher sales in 2005 and 2006 we believe were caused by private stockpiling in fear of a pandemic, and do not represent actual usage. Conclusion A drug induced selection pressure was probably not the cause of the emergence of oseltamivir resistant influenza A(H1N1 viruses in 2007–08 in Norway.

  11. In silico molecular modeling of neuraminidase enzyme H1N1 avian influenza virus and docking with zanamivir ligands

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    Muthiyan Ramachandran

    2012-12-01

    Full Text Available Objective: Neuraminidase is an enzyme aspartic protease that is essential for the life cycle of H1N1. Methods: Constructed a model of Neuraminidase enzyme the 3D structure as template using with Modeller software. The Neuraminidase enzyme model was predicted and validated by Procheck, What check, Errat, Verify-3D and AutoDock web server for reliability. Results: The Modeller homology-modeling algorithm was demonstrated excellent accuracy in blind predictions. The Neuraminidase enzyme model built with little, 35% identity could be accurate enough to be successfully used in receptor based rational drug design. The closest homologue with the highest sequence identity 100% was selected. Zanamivir drug and analogues were retrieved from PubChem database, as well as subjected to docking interaction with Neuraminidase enzyme used AutoDock programme. Based on the root mean square deviation and lowest binding energy values the best docking orientation was selected. The better lowest binding energy value -6.91 was selected of CID_25209232. Conclusions: This study will be used in broad screening of inhibitors of the protein. However, further implemented experimental and clinical verification is needed to establishment these analogues as drug.

  12. Pandemic (H1N1 2009 influenza community transmission was established in one Australian state when the virus was first identified in North America.

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    Heath A Kelly

    Full Text Available BACKGROUND: In mid-June 2009 the State of Victoria in Australia appeared to have the highest notification rate of pandemic (H1N1 2009 influenza in the world. We hypothesise that this was because community transmission of pandemic influenza was already well established in Victoria at the time testing for the novel virus commenced. In contrast, this was not true for the pandemic in other parts of Australia, including Western Australia (WA. METHODS: We used data from detailed case follow-up of patients with confirmed infection in Victoria and WA to demonstrate the difference in the pandemic curve in two Australian states on opposite sides of the continent. We modelled the pandemic in both states, using a susceptible-infected-removed model with Bayesian inference accounting for imported cases. RESULTS: Epidemic transmission occurred earlier in Victoria and later in WA. Only 5% of the first 100 Victorian cases were not locally acquired and three of these were brothers in one family. By contrast, 53% of the first 102 cases in WA were associated with importation from Victoria. Using plausible model input data, estimation of the effective reproductive number for the Victorian epidemic required us to invoke an earlier date for commencement of transmission to explain the observed data. This was not required in modelling the epidemic in WA. CONCLUSION: Strong circumstantial evidence, supported by modelling, suggests community transmission of pandemic influenza was well established in Victoria, but not in WA, at the time testing for the novel virus commenced in Australia. The virus is likely to have entered Victoria and already become established around the time it was first identified in the US and Mexico.

  13. Perturbation of B Cell Gene Expression Persists in HIV-Infected Children Despite Effective Antiretroviral Therapy and Predicts H1N1 Response.

    Science.gov (United States)

    Cotugno, Nicola; De Armas, Lesley; Pallikkuth, Suresh; Rinaldi, Stefano; Issac, Biju; Cagigi, Alberto; Rossi, Paolo; Palma, Paolo; Pahwa, Savita

    2017-01-01

    Despite effective antiretroviral therapy (ART), HIV-infected individuals with apparently similar clinical and immunological characteristics can vary in responsiveness to vaccinations. However, molecular mechanisms responsible for such impairment, as well as biomarkers able to predict vaccine responsiveness in HIV-infected children, remain unknown. Following the hypothesis that a B cell qualitative impairment persists in HIV-infected children (HIV) despite effective ART and phenotypic B cell immune reconstitution, the aim of the current study was to investigate B cell gene expression of HIV compared to age-matched healthy controls (HCs) and to determine whether distinct gene expression patterns could predict the ability to respond to influenza vaccine. To do so, we analyzed prevaccination transcriptional levels of a 96-gene panel in equal numbers of sort-purified B cell subsets (SPBS) isolated from peripheral blood mononuclear cells using multiplexed RT-PCR. Immune responses to H1N1 antigen were determined by hemaglutination inhibition and memory B cell ELISpot assays following trivalent-inactivated influenza vaccination (TIV) for all study participants. Although there were no differences in terms of cell frequencies of SPBS between HIV and HC, the groups were distinguishable based upon gene expression analyses. Indeed, a 28-gene signature, characterized by higher expression of genes involved in the inflammatory response and immune activation was observed in activated memory B cells (CD27 + CD21 - ) from HIV when compared to HC despite long-term viral control (>24 months). Further analysis, taking into account H1N1 responses after TIV in HIV participants, revealed that a 25-gene signature in resting memory (RM) B cells (CD27 + CD21 + ) was able to distinguish vaccine responders from non-responders (NR). In fact, prevaccination RM B cells of responders showed a higher expression of gene sets involved in B cell adaptive immune responses ( APRIL, BTK, BLIMP1 ) and

  14. Fully human broadly neutralizing monoclonal antibodies against influenza A viruses generated from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Weibin [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Chen, Aizhong [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Miao, Yi [Shanghai Xuhui Central Hospital, Shanghai 200031 (China); Xia, Shengli [Center for Disease Control and Prevention of Henan Province, Zhengzhou 450016 (China); Ling, Zhiyang; Xu, Ke; Wang, Tongyan [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Xu, Ying; Cui, Jun; Wu, Hongqiang; Hu, Guiyu; Tian, Lin; Wang, Lingling [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Shu, Yuelong [Chinese Center for Disease Control and Prevention, Beijing 102206 (China); Ma, Xiaowei [Hualan Biological Bacterin Company, Xinxiang 453003 (China); Xu, Bianli; Zhang, Jin [Center for Disease Control and Prevention of Henan Province, Zhengzhou 450016 (China); Lin, Xiaojun, E-mail: linxiaojun@hualan.com [Hualan Biological Bacterin Company, Xinxiang 453003 (China); Bian, Chao, E-mail: cbian@sibs.ac.cn [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Sun, Bing, E-mail: bsun@sibs.ac.cn [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China)

    2013-01-20

    Whether the 2009 pandemic H1N1 influenza vaccine can induce heterosubtypic cross-protective anti-hemagglutinin (HA) neutralizing antibodies is an important issue. We obtained a panel of fully human monoclonal antibodies from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient. Most of the monoclonal antibodies targeted the HA protein but not the HA1 fragment. Among the analyzed antibodies, seven mAbs exhibited neutralizing activity against several influenza A viruses of different subtypes. The conserved linear epitope targeted by the neutralizing mAbs (FIEGGWTGMVDGWYGYHH) is part of the fusion peptide on HA2. Our work suggests that a heterosubtypic neutralizing antibody response primarily targeting the HA stem region exists in recipients of the 2009 pandemic H1N1 influenza vaccine. The HA stem region contains various conserved neutralizing epitopes with the fusion peptide as an important one. This work may aid in the design of a universal influenza A virus vaccine.

  15. Fully human broadly neutralizing monoclonal antibodies against influenza A viruses generated from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient

    International Nuclear Information System (INIS)

    Hu, Weibin; Chen, Aizhong; Miao, Yi; Xia, Shengli; Ling, Zhiyang; Xu, Ke; Wang, Tongyan; Xu, Ying; Cui, Jun; Wu, Hongqiang; Hu, Guiyu; Tian, Lin; Wang, Lingling; Shu, Yuelong; Ma, Xiaowei; Xu, Bianli; Zhang, Jin; Lin, Xiaojun; Bian, Chao; Sun, Bing

    2013-01-01

    Whether the 2009 pandemic H1N1 influenza vaccine can induce heterosubtypic cross-protective anti-hemagglutinin (HA) neutralizing antibodies is an important issue. We obtained a panel of fully human monoclonal antibodies from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient. Most of the monoclonal antibodies targeted the HA protein but not the HA1 fragment. Among the analyzed antibodies, seven mAbs exhibited neutralizing activity against several influenza A viruses of different subtypes. The conserved linear epitope targeted by the neutralizing mAbs (FIEGGWTGMVDGWYGYHH) is part of the fusion peptide on HA2. Our work suggests that a heterosubtypic neutralizing antibody response primarily targeting the HA stem region exists in recipients of the 2009 pandemic H1N1 influenza vaccine. The HA stem region contains various conserved neutralizing epitopes with the fusion peptide as an important one. This work may aid in the design of a universal influenza A virus vaccine.

  16. Research on Anti-influenza A H1N1 Virus in Vitro and Antipyretic Experiments of Major Decoction of Green Dragon Granule%大青龙汤颗粒剂体外抗甲型H1N1流感病毒实验研究

    Institute of Scientific and Technical Information of China (English)

    田连起; 黄鹤归; 叶晓川; 廖鹏程; 黄婕; 周爱军; 刘焱文

    2013-01-01

    Objective:To discuss the effect of Major Decoction of Green Dragon Granule in anti-influenza A H1N1 virus in Vitro and its antipyretic influences to fever rats caused by lipopolysaccharide. Methods: MDCK infected by anti-influenza A H1N1 virus, and combined cytopathic effect ( CPE ) with MTT colorimetric assay, and the drug effect of Major Decoction of Green Dragon Granule inhibiting the biosynthesis of A H1N1 influenza virus,the absorption to influenza virus,the blocking of the accession to cells and killing influenza virus were inspected. Lipopolysaccharide duplicated fever models of rats were used,and rectal temperatures of rats of different groups in different times were measured,curves were drawn,and antipyretic effects were analyzed. Results:The half maximal inhibitory concentration (IC50) of Major Decoction of Green Dragon Granule killing influenza AH1N1 was 12.40 mg·mL-1 ,the therapeutic index (TI) was 1.8. The IC50 of Ribavirin Injection in the same administration route was 0. 45 mg·mL-1 and TI was 1.0. The temperature of the model group had already rised at 1 h after establishing models, reached peak at 5 h, and sustained for 8 h. Compared to the model group, the Major Decoction of Green Dragon Granule of high-dose group and low-dose group had significant differences at 4 - 8 hour. Compared to aspirin group, the Major Decoction of Green Dragon Granule of high-dose group and low-dose group, the range of cooling the temperature was smaller at 1 - 3 hours,and was equal at 4 - 5 hour, but was larger than that of aspirin group at 6 - 8 hour. The difference between Major Decoction of Green Dragon Granule of high-dose group and low-dose group was not significant. Conclusion: Major Decoction of Green Dragon Granule shows certain effect of anti-influenza A H1N1 virus in cell level,and the function form is direct inactivation in a dose dependent manner;but the effect of Major Decoction of Green Dragon Granule in inhibiting the biosynthesis of influenza virus

  17. Seroprevalence of H1N1, H3N2 and H1N2 influenza viruses in pigs in seven European countries in 2002-2003.

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    Van Reeth, Kristien; Brown, Ian H; Dürrwald, Ralf; Foni, Emanuela; Labarque, Geoffrey; Lenihan, Patrick; Maldonado, Jaime; Markowska-Daniel, Iwona; Pensaert, Maurice; Pospisil, Zdenek; Koch, Guus

    2008-05-01

    Avian-like H1N1 and human-like H3N2 swine influenza viruses (SIV) have been considered widespread among pigs in Western Europe since the 1980s, and a novel H1N2 reassortant with a human-like H1 emerged in the mid 1990s. This study, which was part of the EC-funded 'European Surveillance Network for Influenza in Pigs 1', aimed to determine the seroprevalence of the H1N2 virus in different European regions and to compare the relative prevalences of each SIV between regions. Laboratories from Belgium, the Czech Republic, Germany, Italy, Ireland, Poland and Spain participated in an international serosurvey. A total of 4190 sow sera from 651 farms were collected in 2002-2003 and examined in haemagglutination inhibition tests against H1N1, H3N2 and H1N2. In Belgium, Germany, Italy and Spain seroprevalence rates to each of the three SIV subtypes were high (> or =30% of the sows seropositive) to very high (> or =50%), except for a lower H1N2 seroprevalence rate in Italy (13.8%). Most sows in these countries with high pig populations had antibodies to two or three subtypes. In Ireland, the Czech Republic and Poland, where swine farming is less intensive, H1N1 was the dominant subtype (8.0-11.7% seropositives) and H1N2 and H3N2 antibodies were rare (0-4.2% seropositives). Thus, SIV of H1N1, H3N2 and H1N2 subtype are enzootic in swine producing regions of Western Europe. In Central Europe, SIV activity is low and the circulation of H3N2 and H1N2 remains to be confirmed. The evolution and epidemiology of SIV throughout Europe is being further monitored through a second 'European Surveillance Network for Influenza in Pigs'.

  18. A host transcriptional signature for presymptomatic detection of infection in humans exposed to influenza H1N1 or H3N2.

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    Christopher W Woods

    Full Text Available There is great potential for host-based gene expression analysis to impact the early diagnosis of infectious diseases. In particular, the influenza pandemic of 2009 highlighted the challenges and limitations of traditional pathogen-based testing for suspected upper respiratory viral infection. We inoculated human volunteers with either influenza A (A/Brisbane/59/2007 (H1N1 or A/Wisconsin/67/2005 (H3N2, and assayed the peripheral blood transcriptome every 8 hours for 7 days. Of 41 inoculated volunteers, 18 (44% developed symptomatic infection. Using unbiased sparse latent factor regression analysis, we generated a gene signature (or factor for symptomatic influenza capable of detecting 94% of infected cases. This gene signature is detectable as early as 29 hours post-exposure and achieves maximal accuracy on average 43 hours (p = 0.003, H1N1 and 38 hours (p-value = 0.005, H3N2 before peak clinical symptoms. In order to test the relevance of these findings in naturally acquired disease, a composite influenza A signature built from these challenge studies was applied to Emergency Department patients where it discriminates between swine-origin influenza A/H1N1 (2009 infected and non-infected individuals with 92% accuracy. The host genomic response to Influenza infection is robust and may provide the means for detection before typical clinical symptoms are apparent.

  19. Likely correlation between sources of information and acceptability of A/H1N1 swine-origin influenza virus vaccine in Marseille, France.

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    Antoine Nougairède

    Full Text Available BACKGROUND: In France, there was a reluctance to accept vaccination against the A/H1N1 pandemic influenza virus despite government recommendation and investment in the vaccine programme. METHODS AND FINDINGS: We examined the willingness of different populations to accept A/H1N1 vaccination (i in a French hospital among 3315 employees immunized either by in-house medical personnel or mobile teams of MDs and (ii in a shelter housing 250 homeless persons. Google was used to assess the volume of enquiries concerning incidence of influenza. We analyzed the information on vaccination provided by Google, the website of the major French newspapers, and PubMed. Two trust Surveys were used to assess public opinion on the trustworthiness of people in different professions. Paramedics were significantly more reluctant to accept immunisation than qualified medical staff. Acceptance was significantly increased when recommended directly by MDs. Anecdotal cases of directly observed severe infections were followed by enhanced acceptance of paramedical staff. Scientific literature was significantly more in favour of vaccination than Google and French newspaper websites. In the case of the newspaper websites, information correlated with their recognised political reputations, although they would presumably claim independence from political bias. The Trust Surveys showed that politicians were highly dis-trusted in contrast with doctors and pharmacists who were considered much more trustworthy. CONCLUSIONS: The low uptake of the vaccine could reflect failure to convey high quality medical information and advice relating to the benefits of being vaccinated. We believe that the media and internet contributed to this problem by raising concerns within the general population and that failure to involve GPs in the control programme may have been a mistake. GPs are highly regarded by the public and can provide face-to-face professional advice and information. The top

  20. Immune response after one or two doses of pandemic influenza A (H1N1) monovalent, AS03-adjuvanted vaccine in HIV infected adults

    DEFF Research Database (Denmark)

    Bybeck Nielsen, Allan; Nielsen, Henriette Schjønning; Nielsen, Lars

    2012-01-01

    INTRODUCTION: Continued research is needed to evaluate and improve the immunogenicity of influenza vaccines in HIV infected patients. We aimed to determine the antibody responses after one or two doses of the AS03-adjuvanted pandemic influenza A (H1N1) vaccine in HIV infected patients. METHOD......: Following the influenza season 2009/2010, 219 HIV infected patients were included and divided into three groups depending on whether they received none (n=60), one (n=31) or two (n=128) doses of pandemic influenza A (H1N1) vaccine. At inclusion, antibody titers for all patients were analyzed and compared...... to pre-pandemic antibody titers analyzed from serum samples in a local storage facility. RESULTS: 4-9 months after a single immunization, we found a seroprotection rate of 77.4% and seroconversion rate of 67.7%. After two immunizations the rates increased significantly to seroprotection rate of 97...

  1. Mortality, severe acute respiratory infection, and influenza-like illness associated with influenza A(H1N1pdm09 in Argentina, 2009.

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    Eduardo Azziz-Baumgartner

    Full Text Available INTRODUCTION: While there is much information about the burden of influenza A(H1N1pdm09 in North America, little data exist on its burden in South America. METHODS: During April to December 2009, we actively searched for persons with severe acute respiratory infection and influenza-like illness (ILI in three sentinel cities. A proportion of case-patients provided swabs for influenza testing. We estimated the number of case-patients that would have tested positive for influenza by multiplying the number of untested case-patients by the proportion who tested positive. We estimated rates by dividing the estimated number of case-patients by the census population after adjusting for the proportion of case-patients with missing illness onset information and ILI case-patients who visited physicians multiple times for one illness event. RESULTS: We estimated that the influenza A(H1N1pdm09 mortality rate per 100,000 person-years (py ranged from 1.5 among persons aged 5-44 years to 5.6 among persons aged ≥ 65 years. A(H1N1pdm09 hospitalization rates per 100,000 py ranged between 26.9 among children aged <5 years to 41.8 among persons aged ≥ 65 years. Influenza A(H1N1pdm09 ILI rates per 100 py ranged between 1.6 among children aged <5 to 17.1 among persons aged 45-64 years. While 9 (53% of 17 influenza A(H1N1pdm09 decedents with available data had obesity and 7 (17% of 40 had diabetes, less than 4% of surviving influenza A(H1N1pdm09 case-patients had these pre-existing conditions (p ≤ 0.001. CONCLUSION: Influenza A(H1N1pdm09 caused a similar burden of disease in Argentina as in other countries. Such disease burden suggests the potential value of timely influenza vaccinations.

  2. Potency of whole virus particle and split virion vaccines using dissolving microneedle against challenges of H1N1 and H5N1 influenza viruses in mice.

    Science.gov (United States)

    Nakatsukasa, Akihiro; Kuruma, Koji; Okamatsu, Masatoshi; Hiono, Takahiro; Suzuki, Mizuho; Matsuno, Keita; Kida, Hiroshi; Oyamada, Takayoshi; Sakoda, Yoshihiro

    2017-05-15

    Transdermal vaccination using a microneedle (MN) confers enhanced immunity compared with subcutaneous (SC) vaccination. Here we developed a novel dissolving MN patch for the influenza vaccine. The potencies of split virion and whole virus particle (WVP) vaccines prepared from A/Puerto Rico/8/1934 (H1N1) and A/duck/Hokkaido/Vac-3/2007 (H5N1), respectively, were evaluated. MN vaccination induced higher neutralizing antibody responses than SC vaccination in mice. Moreover, MN vaccination with a lower dose of antigens conferred protective immunity against lethal challenges of influenza viruses than SC vaccination in mice. These results suggest that the WVP vaccines administered using MN are an effective combination for influenza vaccine to be further validated in humans. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Whole genome characterization of human influenza A(H1N1)pdm09 viruses isolated from Kenya during the 2009 pandemic.

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    Gachara, George; Symekher, Samuel; Otieno, Michael; Magana, Japheth; Opot, Benjamin; Bulimo, Wallace

    2016-06-01

    An influenza pandemic caused by a novel influenza virus A(H1N1)pdm09 spread worldwide in 2009 and is estimated to have caused between 151,700 and 575,400 deaths globally. While whole genome data on new virus enables a deeper insight in the pathogenesis, epidemiology, and drug sensitivities of the circulating viruses, there are relatively limited complete genetic sequences available for this virus from African countries. We describe herein the full genome analysis of influenza A(H1N1)pdm09 viruses isolated in Kenya between June 2009 and August 2010. A total of 40 influenza A(H1N1)pdm09 viruses isolated during the pandemic were selected. The segments from each isolate were amplified and directly sequenced. The resulting sequences of individual gene segments were concatenated and used for subsequent analysis. These were used to infer phylogenetic relationships and also to reconstruct the time of most recent ancestor, time of introduction into the country, rates of substitution and to estimate a time-resolved phylogeny. The Kenyan complete genome sequences clustered with globally distributed clade 2 and clade 7 sequences but local clade 2 viruses did not circulate beyond the introductory foci while clade 7 viruses disseminated country wide. The time of the most recent common ancestor was estimated between April and June 2009, and distinct clusters circulated during the pandemic. The complete genome had an estimated rate of nucleotide substitution of 4.9×10(-3) substitutions/site/year and greater diversity in surface expressed proteins was observed. We show that two clades of influenza A(H1N1)pdm09 virus were introduced into Kenya from the UK and the pandemic was sustained as a result of importations. Several closely related but distinct clusters co-circulated locally during the peak pandemic phase but only one cluster dominated in the late phase of the pandemic suggesting that it possessed greater adaptability. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Genetic and biological characterisation of an avian-like H1N2 swine influenza virus generated by reassortment of circulating avian-like H1N1 and H3N2 subtypes in Denmark.

    Science.gov (United States)

    Trebbien, Ramona; Bragstad, Karoline; Larsen, Lars Erik; Nielsen, Jens; Bøtner, Anette; Heegaard, Peter M H; Fomsgaard, Anders; Viuff, Birgitte; Hjulsager, Charlotte Kristiane

    2013-09-18

    The influenza A virus subtypes H1N1, H1N2 and H3N2 are the most prevalent subtypes in swine. In 2003, a reassorted H1N2 swine influenza virus (SIV) subtype appeared and became prevalent in Denmark. In the present study, the reassortant H1N2 subtype was characterised genetically and the infection dynamics compared to an "avian-like" H1N1 virus by an experimental infection study. Sequence analyses were performed of the H1N2 virus. Two groups of pigs were inoculated with the reassortant H1N2 virus and an "avian-like" H1N1 virus, respectively, followed by inoculation with the opposite subtype four weeks later. Measurements of HI antibodies and acute phase proteins were performed. Nasal virus excretion and virus load in lungs were determined by real-time RT-PCR. The phylogenetic analysis revealed that the reassorted H1N2 virus contained a European "avian-like" H1-gene and a European "swine-like" N2-gene, thus being genetically distinct from most H1N2 viruses circulating in Europe, but similar to viruses reported in 2009/2010 in Sweden and Italy. Sequence analyses of the internal genes revealed that the reassortment probably arose between circulating Danish "avian-like" H1N1 and H3N2 SIVs. Infected pigs developed cross-reactive antibodies, and increased levels of acute phase proteins after inoculations. Pigs inoculated with H1N2 exhibited nasal virus excretion for seven days, peaking day 1 after inoculation two days earlier than H1N1 infected pigs and at a six times higher level. The difference, however, was not statistically significant. Pigs euthanized on day 4 after inoculation, had a high virus load in all lung lobes. After the second inoculation, the nasal virus excretion was minimal. There were no clinical sign except elevated body temperature under the experimental conditions. The "avian-like" H1N2 subtype, which has been established in the Danish pig population at least since 2003, is a reassortant between circulating swine "avian-like" H1N1 and H3N2. The Danish

  5. Clinical features and risk factors for severe and critical pregnant women with 2009 pandemic H1N1 influenza infection in China

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    Zhang Peng-jun

    2012-02-01

    Full Text Available Abstract Background 2009 pandemic H1N1 (pH1N1 influenza posed an increased risk of severe illness among pregnant women. Data on risk factors associated with death of pregnant women and neonates with pH1N1 infections are limited outside of developed countries. Methods Retrospective observational study in 394 severe or critical pregnant women admitted to a hospital with pH1N1 influenza from Sep. 1, 2009 to Dec. 31, 2009. rRT-PCR testing was used to confirm infection. In-hospital mortality was the primary endpoint of this study. Univariable logistic analysis and multivariate logistic regression analysis were used to investigate the potential factors on admission that might be associated with the maternal and neonatal mortality. Results 394 pregnant women were included, 286 were infected with pH1N1 in the third trimester. 351 had pneumonia, and 77 died. A PaO2/FiO2 ≤ 200 (odds ratio (OR, 27.16; 95% confidence interval (CI, 2.64-279.70 and higher BMI (i.e. ≥ 30 on admission (OR, 1.26; 95% CI, 1.09 to 1.47 were independent risk factors for maternal death. Of 211 deliveries, 146 neonates survived. Premature delivery (OR, 4.17; 95% CI, 1.19-14.56 was associated neonatal mortality. Among 186 patients who received mechanical ventilation, 83 patients were treated with non-invasive ventilation (NIV and 38 were successful with NIV. The death rate was lower among patients who initially received NIV than those who were initially intubated (24/83, 28.9% vs 43/87, 49.4%; p = 0.006. Septic shock was an independent risk factor for failure of NIV. Conclusions Severe hypoxemia and higher BMI on admission were associated with adverse outcomes for pregnant women. Preterm delivery was a risk factor for neonatal death among pregnant women with pH1N1 influenza infection. NIV may be useful in selected pregnant women without septic shock.

  6. Integrative study of pandemic A/H1N1 influenza infections: design and methods of the CoPanFlu-France cohort

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    Lapidus Nathanael

    2012-06-01

    Full Text Available Abstract Background The risk of influenza infection depends on biological characteristics, individual or collective behaviors and the environmental context. The Cohorts for Pandemic Influenza (CoPanFlu France study was set up in 2009 after the identification of the novel swine-origin A/H1N1 pandemic influenza virus. This cohort of 601 households (1450 subjects representative for the general population aims at using an integrative approach to study the risk and characteristics of influenza infection as a complex combination of data collected from questionnaires regarding sociodemographic, medical, behavioral characteristics of subjects and indoor environment, using biological samples or environmental databases. Methods/Design Households were included between December 2009 and July 2010. The design of this study relies on systematic follow-up visits between influenza seasons and additional visits during influenza seasons, when an influenza-like illness is detected in a household via an active surveillance system. During systematic visits, a nurse collects individual and environmental data on questionnaires and obtains blood samples from all members of the household. When an influenza-like-illness is detected, a nurse visits the household three times during the 12 following days, and collects data on questionnaires regarding exposure and symptoms, and biological samples (including nasal swabs from all subjects in the household. The end of the follow-up period is expected in fall 2012. Discussion The large amount of data collected throughout the follow-up will permit a multidisciplinary study of influenza infections. Additional data is being collected and analyzed in this ongoing cohort. The longitudinal analysis of these households will permit integrative analyses of complex phenomena such as individual, collective and environmental risk factors of infection, routes of transmission, or determinants of the immune response to infection or vaccination.

  7. Extracorporeal Membrane Oxygenation and Modern Detoxification Techniques in a Puerpera with Viral and Bacterial Pneumonia Caused by Flu A(H1N1 Virus

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    R. A. Kornelyuk

    2017-01-01

    Full Text Available Outbreaks of viral infections have become a global healthcare challenge over the last decade. The 2009—2010 flu A (H1N1 outbreak resulted in global pandemia, associated with high morbidity and mortality reaching 31%. Another flu A (H1N1 outbreak occurred in 2015—2016. There is a strong probability that it may be repeated in the future. This infection is associated with its high incidence among pregnant women. There are some published reports describing the efficacy and safety of veno%venous extracorporeal membrane oxygenation (ECMO in patients with severe acute respiratory distress syndrome that is refractory to standard therapeutic options. The article presents a clinical case of a successful use of extracorporeal membrane oxygenation and intermittent renal replacement therapy in a puerpera with acute respiratory distress syndrome caused by flu A (H1N1-related severe viral and bacterial pneumonia. The positive effects of the combination of veno%venous extracorporeal membrane oxygenation and modern detoxification techniques have been demonstrated. Revealed organizational problemswere related to selection criteria for prescription of extracorporeal gas exchange, as well as to carrying out the procedure in an institution in the deficiency of the experienced staff and corresponding equipment.

  8. Entrapment of H1N1 Influenza Virus Derived Conserved Peptides in PLGA Nanoparticles Enhances T Cell Response and Vaccine Efficacy in Pigs.

    Science.gov (United States)

    Hiremath, Jagadish; Kang, Kyung-il; Xia, Ming; Elaish, Mohamed; Binjawadagi, Basavaraj; Ouyang, Kang; Dhakal, Santosh; Arcos, Jesus; Torrelles, Jordi B; Jiang, X; Lee, Chang Won; Renukaradhya, Gourapura J

    2016-01-01

    Pigs are believed to be one of the important sources of emerging human and swine influenza viruses (SwIV). Influenza virus conserved peptides have the potential to elicit cross-protective immune response, but without the help of potent adjuvant and delivery system they are poorly immunogenic. Biodegradable polylactic-co-glycolic acid (PLGA) nanoparticle (PLGA-NP) based vaccine delivery system enhances cross-presentation of antigens by the professional antigen presenting cells. In this study, Norovirus P particle containing SwIV M2e (extracellular domain of the matrix protein 2) chimera and highly conserved two each of H1N1 peptides of pandemic 2009 and classical human influenza viruses were entrapped in PLGA-NPs. Influenza antibody-free pigs were vaccinated with PLGA-NPs peptides cocktail vaccine twice with or without an adjuvant, Mycobacterium vaccae whole cell lysate, intranasally as mist. Vaccinated pigs were challenged with a virulent heterologous zoonotic SwIV H1N1, and one week later euthanized and the lung samples were analyzed for the specific immune response and viral load. Clinically, pigs vaccinated with PLGA-NP peptides vaccine had no fever and flu symptoms, and the replicating challenged SwIV was undetectable in the bronchoalveolar lavage fluid. Immunologically, PLGA-NP peptides vaccination (without adjuvant) significantly increased the frequency of antigen-specific IFNγ secreting CD4 and CD8 T cells response in the lung lymphocytes, despite not boosting the antibody response both at pre- and post-challenge. In summary, our data indicated that nanoparticle-mediated delivery of conserved H1N1 influenza peptides induced the virus specific T cell response in the lungs and reduced the challenged heterologous virus load in the airways of pigs.

  9. Entrapment of H1N1 Influenza Virus Derived Conserved Peptides in PLGA Nanoparticles Enhances T Cell Response and Vaccine Efficacy in Pigs.

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    Jagadish Hiremath

    Full Text Available Pigs are believed to be one of the important sources of emerging human and swine influenza viruses (SwIV. Influenza virus conserved peptides have the potential to elicit cross-protective immune response, but without the help of potent adjuvant and delivery system they are poorly immunogenic. Biodegradable polylactic-co-glycolic acid (PLGA nanoparticle (PLGA-NP based vaccine delivery system enhances cross-presentation of antigens by the professional antigen presenting cells. In this study, Norovirus P particle containing SwIV M2e (extracellular domain of the matrix protein 2 chimera and highly conserved two each of H1N1 peptides of pandemic 2009 and classical human influenza viruses were entrapped in PLGA-NPs. Influenza antibody-free pigs were vaccinated with PLGA-NPs peptides cocktail vaccine twice with or without an adjuvant, Mycobacterium vaccae whole cell lysate, intranasally as mist. Vaccinated pigs were challenged with a virulent heterologous zoonotic SwIV H1N1, and one week later euthanized and the lung samples were analyzed for the specific immune response and viral load. Clinically, pigs vaccinated with PLGA-NP peptides vaccine had no fever and flu symptoms, and the replicating challenged SwIV was undetectable in the bronchoalveolar lavage fluid. Immunologically, PLGA-NP peptides vaccination (without adjuvant significantly increased the frequency of antigen-specific IFNγ secreting CD4 and CD8 T cells response in the lung lymphocytes, despite not boosting the antibody response both at pre- and post-challenge. In summary, our data indicated that nanoparticle-mediated delivery of conserved H1N1 influenza peptides induced the virus specific T cell response in the lungs and reduced the challenged heterologous virus load in the airways of pigs.

  10. Antigenic and genomic characterization of human influenza A and B viruses circulating in Argentina after the introduction of influenza A(H1N1)pdm09.

    Science.gov (United States)

    Russo, Mara L; Pontoriero, Andrea V; Benedetti, Estefania; Czech, Andrea; Avaro, Martin; Periolo, Natalia; Campos, Ana M; Savy, Vilma L; Baumeister, Elsa G

    2014-12-01

    This study was conducted as part of the Argentinean Influenza and other Respiratory Viruses Surveillance Network, in the context of the Global Influenza Surveillance carried out by the World Health Organization (WHO). The objective was to study the activity and the antigenic and genomic characteristics of circulating viruses for three consecutive seasons (2010, 2011 and 2012) in order to investigate the emergence of influenza viral variants. During the study period, influenza virus circulation was detected from January to December. Influenza A and B, and all current subtypes of human influenza viruses, were present each year. Throughout the 2010 post-pandemic season, influenza A(H1N1)pdm09, unexpectedly, almost disappeared. The haemagglutinin (HA) of the A(H1N1)pdm09 viruses studied were segregated in a different genetic group to those identified during the 2009 pandemic, although they were still antigenically closely related to the vaccine strain A/California/07/2009. Influenza A(H3N2) viruses were the predominant strains circulating during the 2011 season, accounting for nearly 76 % of influenza viruses identified. That year, all HA sequences of the A(H3N2) viruses tested fell into the A/Victoria/208/2009 genetic clade, but remained antigenically related to A/Perth/16/2009 (reference vaccine recommended for this three-year period). A(H3N2) viruses isolated in 2012 were antigenically closely related to A/Victoria/361/2011, recommended by the WHO as the H3 component for the 2013 Southern Hemisphere formulation. B viruses belonging to the B/Victoria lineage circulated in 2010. A mixed circulation of viral variants of both B/Victoria and B/Yamagata lineages was detected in 2012, with the former being predominant. A(H1N1)pdm09 viruses remained antigenically closely related to the vaccine virus A/California/7/2009; A(H3N2) viruses continually evolved into new antigenic clusters and both B lineages, B/Victoria/2/87-like and B/Yamagata/16/88-like viruses, were observed

  11. Studies on the antibody response of mice and humans after immunization with potential influenza virus A (H1N1) vaccines

    International Nuclear Information System (INIS)

    Poumbourios, P.; Jackson, D.C.; Oxford, J.S.

    1993-01-01

    The antibody response of mice and adult humans to immunization with subunit vaccines derived from a pair of antigenically distinct influenza A H1N1 viruses isolate in eggs was investigated. Although the haemagglutinin molecule of each virus differed by only three amino acid residues, highly specific antibody responses were elicited in mice as determined by haemagglutination inhibition and radioimmunoprecipitation assays. Results from competitive radioimmunoassays using monoclonal antibodies of known specificity and a study of the reactivity of mouse antisera with H1N1 field strains indicated that the marked differences in the antibody responses to the two vaccines was due to an amino acid substitution in the distal tip of the haemagglutinin molecule. In contrast, cross reactive antibody responses were elicited in humans presumably due to exposure to viruses related to the candidate vaccine prior to vaccination. Although immunogenic differences are apparent in this pair of antigenically distinct viruses in naive laboratory animals, these differences are not apparent following vaccination of humans that had prior exposure to related viruses. 21 refs., 5 tabs., 4 figs

  12. Characterization of influenza A(H1N1)pdm09 viruses isolated from Nepalese and Indian outbreak patients in early 2015.

    Science.gov (United States)

    Nakamura, Kazuya; Shirakura, Masayuki; Fujisaki, Seiichiro; Kishida, Noriko; Burke, David F; Smith, Derek J; Kuwahara, Tomoko; Takashita, Emi; Takayama, Ikuyo; Nakauchi, Mina; Chadha, Mandeep; Potdar, Varsha; Bhushan, Arvind; Upadhyay, Bishnu Prasad; Shakya, Geeta; Odagiri, Takato; Kageyama, Tsutomu; Watanabe, Shinji

    2017-09-01

    We characterized influenza A(H1N1)pdm09 isolates from large-scale outbreaks that occurred in Nepal and India in early 2015. Although no specific viral features, which may have caused the outbreaks, were identified, an S84N substitution in hemagglutinin was frequently observed. Chronological phylogenetic analysis revealed that these Nepalese and Indian viruses possessing the S84N substitution constitute potential ancestors of the novel genetic subclade 6B.1 virus that spread globally in the following (2015/16) influenza season. Thus, active surveillance of circulating influenza viruses in the Southern Asia region, including Nepal and India, would be beneficial for detecting novel variant viruses prior to their worldwide spread. © 2017 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  13. Clinical aspects of influenza A (H1N1 in HIV-infected individuals in São Paulo during the pandemic of 2009

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    Rosana Del Bianco

    Full Text Available OBJECTIVE: To describe the clinical aspects of H1N1 among HIV coinfected patients seen at a reference center for AIDS treatment in São Paulo, Brazil. Design: Observational and prospective cohort study. METHODS: Descriptive study of clinical and laboratory investigation of HIV-infected patients with confirmed diagnosis of influenza A (H1N1 in 2009. We analyzed patients monitored in CRT/DST/AIDS, a specialized service for people living with HIV, located in São Paulo, Brazil. RESULTS: 108 individuals presented with symptoms of H1N1 infection at the CRT DST/AIDS in 2009. Eighteen patients (16.7% had confirmation of the diagnosis of influenza A. Among the confirmed cases, ten (55.6% were hospitalized and eight (44.4% were outpatients. Dyspnea was present in nine patients (50%, hemoptysis in three (16%. Six patients (60% required therapy with supplemental oxygen. All patients had good clinical outcomes and none died. CONCLUSIONS: In our hospital, the symptoms that led patients to seek medical care were similar to the common flu. Hospital admission and the early introduction of antibiotics associated with oseltamivir may have been the cause of the favorable outcome of our cases.

  14. Reassortment and mutations associated with emergence and spread of oseltamivir-resistant seasonal influenza A/H1N1 viruses in 2005-2009.

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    Ji-Rong Yang

    Full Text Available A dramatic increase in the frequency of the H275Y mutation in the neuraminidase (NA, conferring resistance to oseltamivir, has been detected in human seasonal influenza A/H1N1 viruses since the influenza season of 2007-2008. The resistant viruses emerged in the ratio of 14.3% and quickly reached 100% in Taiwan from September to December 2008. To explore the mechanisms responsible for emergence and spread of the resistant viruses, we analyzed the complete genome sequences of 25 viruses collected during 2005-2009 in Taiwan, which were chosen from various clade viruses, 1, 2A, 2B-1, 2B-2, 2C-1 and 2C-2 by the classification of hemagglutinin (HA sequences. Our data revealed that the dominant variant, clade 2B-1, in the 2007-2008 influenza emerged through an intra-subtype 4+4 reassortment between clade 1 and 2 viruses. The dominant variant acquired additional substitutions, including A206T in HA, H275Y and D354G in NA, L30R and H41P in PB1-F2, and V411I and P453S in basic polymerase 2 (PB2 proteins and subsequently caused the 2008-2009 influenza epidemic in Taiwan, accompanying the widespread oseltamivir-resistant viruses. We also characterized another 3+5 reassortant virus which became double resistant to oseltamivir and amantadine. Comparison of oseltamivir-resistant influenza A/H1N1 viruses belonging to various clades in our study highlighted that both reassortment and mutations were associated with emergence and spread of these viruses and the specific mutation, H275Y, conferring to antiviral resistance, was acquired in a hitch-hiking mechanism during the viral evolutionary processes.

  15. Comparative Pathogenesis of an Avian H5N2 and a Swine H1N1 Influenza Virus in Pigs

    DEFF Research Database (Denmark)

    De Vleeschauwer, Annebel; Atanasova, Kalina; Van Borm, Steven

    2009-01-01

    Pigs are considered intermediate hosts for the transmission of avian influenza viruses (AIVs) to humans but the basic organ pathogenesis of AIVs in pigs has been barely studied. We have used 42 four-week-old influenza naive pigs and two different inoculation routes (intranasal and intratracheal) ...

  16. Pandemic Swine-Origin H1N1 Influenza Virus Replicates to Higher Levels and Induces More Fever and Acute Inflammatory Cytokines in Cynomolgus versus Rhesus Monkeys and Can Replicate in Common Marmosets.

    Directory of Open Access Journals (Sweden)

    Petra Mooij

    Full Text Available The close immunological and physiological resemblance with humans makes non-human primates a valuable model for studying influenza virus pathogenesis and immunity and vaccine efficacy against infection. Although both cynomolgus and rhesus macaques are frequently used in influenza virus research, a direct comparison of susceptibility to infection and disease has not yet been performed. In the current study a head-to-head comparison was made between these species, by using a recently described swine-origin pandemic H1N1 strain, A/Mexico/InDRE4487/2009. In comparison to rhesus macaques, cynomolgus macaques developed significantly higher levels of virus replication in the upper airways and in the lungs, involving both peak level and duration of virus production, as well as higher increases in body temperature. In contrast, clinical symptoms, including respiratory distress, were more easily observed in rhesus macaques. Expression of sialyl-α-2,6-Gal saccharides, the main receptor for human influenza A viruses, was 50 to 73 times more abundant in trachea and bronchus of cynomolgus macaques relative to rhesus macaques. The study also shows that common marmosets, a New World non-human primate species, are susceptible to infection with pandemic H1N1. The study results favor the cynomolgus macaque as model for pandemic H1N1 influenza virus research because of the more uniform and high levels of virus replication, as well as temperature increases, which may be due to a more abundant expression of the main human influenza virus receptor in the trachea and bronchi.

  17. Genetic characterization of an adapted pandemic 2009 H1N1 influenza virus that reveals improved replication rates in human lung epithelial cells

    International Nuclear Information System (INIS)

    Wörmann, Xenia; Lesch, Markus; Welke, Robert-William; Okonechnikov, Konstantin; Abdurishid, Mirshat; Sieben, Christian; Geissner, Andreas; Brinkmann, Volker; Kastner, Markus; Karner, Andreas; Zhu, Rong; Hinterdorfer, Peter; Anish, Chakkumkal; Seeberger, Peter H.; Herrmann, Andreas

    2016-01-01

    The 2009 influenza pandemic originated from a swine-origin H1N1 virus, which, although less pathogenic than anticipated, may acquire additional virulence-associated mutations in the future. To estimate the potential risk, we sequentially passaged the isolate A/Hamburg/04/2009 in A549 human lung epithelial cells. After passage 6, we observed a 100-fold increased replication rate. High-throughput sequencing of viral gene segments identified five dominant mutations, whose contribution to the enhanced growth was analyzed by reverse genetics. The increased replication rate was pinpointed to two mutations within the hemagglutinin (HA) gene segment (HA_1 D130E, HA_2 I91L), near the receptor binding site and the stem domain. The adapted virus also replicated more efficiently in mice in vivo. Enhanced replication rate correlated with increased fusion pH of the HA protein and a decrease in receptor affinity. Our data might be relevant for surveillance of pre-pandemic strains and development of high titer cell culture strains for vaccine production. - Highlights: • We observed a spontaneous mutation of a 2009-pandemic H1N1 influenza virus in vitro. • The adaptation led to a 100-fold rise in replication rate in human A549 cells. • Adaptation was caused by two mutations in the HA gene segment. • Adaptation correlates with increased fusion pH and decreased receptor affinity.

  18. Genetic characterization of an adapted pandemic 2009 H1N1 influenza virus that reveals improved replication rates in human lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Wörmann, Xenia [Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin (Germany); Lesch, Markus [Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin (Germany); Steinbeis Innovation gGmbH, Center for Systems Biomedicine, Falkensee (Germany); Welke, Robert-William [Department of Biology, Molecular Biophysics, IRI Life Sciences, Humboldt-Universität zu Berlin (Germany); Okonechnikov, Konstantin; Abdurishid, Mirshat [Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin (Germany); Sieben, Christian [Department of Biology, Molecular Biophysics, IRI Life Sciences, Humboldt-Universität zu Berlin (Germany); Geissner, Andreas [Department for Biomolecular Systems, Max Planck Institute for Colloids and Interfaces, Potsdam (Germany); Institute of Chemistry and Biochemistry, Free University, Berlin (Germany); Brinkmann, Volker [Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin (Germany); Kastner, Markus [Institute for Biophysics, Johannes Kepler University, Linz (Austria); Karner, Andreas [Center for Advanced Bioanalysis GmbH (CBL), Linz (Austria); Zhu, Rong; Hinterdorfer, Peter [Institute for Biophysics, Johannes Kepler University, Linz (Austria); Anish, Chakkumkal [Department for Biomolecular Systems, Max Planck Institute for Colloids and Interfaces, Potsdam (Germany); Seeberger, Peter H. [Department for Biomolecular Systems, Max Planck Institute for Colloids and Interfaces, Potsdam (Germany); Institute of Chemistry and Biochemistry, Free University, Berlin (Germany); Herrmann, Andreas [Department of Biology, Molecular Biophysics, IRI Life Sciences, Humboldt-Universität zu Berlin (Germany); and others

    2016-05-15

    The 2009 influenza pandemic originated from a swine-origin H1N1 virus, which, although less pathogenic than anticipated, may acquire additional virulence-associated mutations in the future. To estimate the potential risk, we sequentially passaged the isolate A/Hamburg/04/2009 in A549 human lung epithelial cells. After passage 6, we observed a 100-fold increased replication rate. High-throughput sequencing of viral gene segments identified five dominant mutations, whose contribution to the enhanced growth was analyzed by reverse genetics. The increased replication rate was pinpointed to two mutations within the hemagglutinin (HA) gene segment (HA{sub 1} D130E, HA{sub 2} I91L), near the receptor binding site and the stem domain. The adapted virus also replicated more efficiently in mice in vivo. Enhanced replication rate correlated with increased fusion pH of the HA protein and a decrease in receptor affinity. Our data might be relevant for surveillance of pre-pandemic strains and development of high titer cell culture strains for vaccine production. - Highlights: • We observed a spontaneous mutation of a 2009-pandemic H1N1 influenza virus in vitro. • The adaptation led to a 100-fold rise in replication rate in human A549 cells. • Adaptation was caused by two mutations in the HA gene segment. • Adaptation correlates with increased fusion pH and decreased receptor affinity.

  19. Memory immune responses against pandemic (H1N1 2009 influenza virus induced by a whole particle vaccine in cynomolgus monkeys carrying Mafa-A1*052:02.

    Directory of Open Access Journals (Sweden)

    Masahiko Arikata

    Full Text Available We made an H1N1 vaccine candidate from a virus library consisting of 144 ( = 16 HA×9 NA non-pathogenic influenza A viruses and examined its protective effects against a pandemic (2009 H1N1 strain using immunologically naïve cynomolgus macaques to exclude preexisting immunity and to employ a preclinical study since preexisting immunity in humans previously vaccinated or infected with influenza virus might make comparison of vaccine efficacy difficult. Furthermore, macaques carrying a major histocompatibility complex class I molecule, Mafa-A1*052:02, were used to analyze peptide-specific CD8(+ T cell responses. Sera of macaques immunized with an inactivated whole particle formulation without addition of an adjuvant showed higher neutralization titers against the vaccine strain A/Hokkaido/2/1981 (H1N1 than did sera of macaques immunized with a split formulation. Neutralization activities against the pandemic strain A/Narita/1/2009 (H1N1 in sera of macaques immunized twice with the split vaccine reached levels similar to those in sera of macaques immunized once with the whole particle vaccine. After inoculation with the pandemic virus, the virus was detected in nasal samples of unvaccinated macaques for 6 days after infection and for 2.67 days and 5.33 days on average in macaques vaccinated with the whole particle vaccine and the split vaccine, respectively. After the challenge infection, recall neutralizing antibody responses against the pandemic virus and CD8(+ T cell responses specific for nucleoprotein peptide NP262-270 bound to Mafa-A1*052:02 in macaques vaccinated with the whole particle vaccine were observed more promptly or more vigorously than those in macaques vaccinated with the split vaccine. These findings demonstrated that the vaccine derived from our virus library was effective for pandemic virus infection in macaques and that the whole particle vaccine conferred more effective memory and broader cross-reactive immune responses

  20. Pandemic H1N1 influenza A directly induces a robust and acute inflammatory gene signature in primary human bronchial epithelial cells downstream of membrane fusion

    Energy Technology Data Exchange (ETDEWEB)

    Paquette, Stéphane G. [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario (Canada); Banner, David [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); Chi, Le Thi Bao [Department of Microbiology, Hue University of Medicine and Pharmacy, Thua Thien Hue (Viet Nam); Carlo Urbani Centre, Hue University of Medicine and Pharmacy, Thua Thien Hue (Viet Nam); Leon, Alberto J. [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); International Institute of Infection and Immunity, Shantou University Medical College, Shantou, Guangdong (China); Xu, Luoling; Ran, Longsi [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); Huang, Stephen S.H. [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, Ontario (Canada); Farooqui, Amber [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); International Institute of Infection and Immunity, Shantou University Medical College, Shantou, Guangdong (China); and others

    2014-01-05

    Pandemic H1N1 influenza A (H1N1pdm) elicits stronger pulmonary inflammation than previously circulating seasonal H1N1 influenza A (sH1N1), yet mechanisms of inflammatory activation in respiratory epithelial cells during H1N1pdm infection are unclear. We investigated host responses to H1N1pdm/sH1N1 infection and virus entry mechanisms in primary human bronchial epithelial cells in vitro. H1N1pdm infection rapidly initiated a robust inflammatory gene signature (3 h post-infection) not elicited by sH1N1 infection. Protein secretion inhibition had no effect on gene induction. Infection with membrane fusion deficient H1N1pdm failed to induce robust inflammatory gene expression which was rescued with restoration of fusion ability, suggesting H1N1pdm directly triggered the inflammatory signature downstream of membrane fusion. Investigation of intra-virion components revealed H1N1pdm viral RNA (vRNA) triggered a stronger inflammatory phenotype than sH1N1 vRNA. Thus, our study is first to report H1N1pdm induces greater inflammatory gene expression than sH1N1 in vitro due to direct virus–epithelial cell interaction. - Highlights: • We investigated H1N1pdm/sH1N1 infection in primary epithelial cells. • H1N1pdm directly initiated a robust inflammatory gene signature, sH1N1 did not. • H1N1pdm viral RNA triggered a stronger response than sH1N1. • H1N1pdm induces greater response due to direct virus–cell interaction. • These results have potential to impact vaccine and therapeutic development.

  1. Pandemic H1N1 influenza A directly induces a robust and acute inflammatory gene signature in primary human bronchial epithelial cells downstream of membrane fusion

    International Nuclear Information System (INIS)

    Paquette, Stéphane G.; Banner, David; Chi, Le Thi Bao; Leon, Alberto J.; Xu, Luoling; Ran, Longsi; Huang, Stephen S.H.; Farooqui, Amber

    2014-01-01

    Pandemic H1N1 influenza A (H1N1pdm) elicits stronger pulmonary inflammation than previously circulating seasonal H1N1 influenza A (sH1N1), yet mechanisms of inflammatory activation in respiratory epithelial cells during H1N1pdm infection are unclear. We investigated host responses to H1N1pdm/sH1N1 infection and virus entry mechanisms in primary human bronchial epithelial cells in vitro. H1N1pdm infection rapidly initiated a robust inflammatory gene signature (3 h post-infection) not elicited by sH1N1 infection. Protein secretion inhibition had no effect on gene induction. Infection with membrane fusion deficient H1N1pdm failed to induce robust inflammatory gene expression which was rescued with restoration of fusion ability, suggesting H1N1pdm directly triggered the inflammatory signature downstream of membrane fusion. Investigation of intra-virion components revealed H1N1pdm viral RNA (vRNA) triggered a stronger inflammatory phenotype than sH1N1 vRNA. Thus, our study is first to report H1N1pdm induces greater inflammatory gene expression than sH1N1 in vitro due to direct virus–epithelial cell interaction. - Highlights: • We investigated H1N1pdm/sH1N1 infection in primary epithelial cells. • H1N1pdm directly initiated a robust inflammatory gene signature, sH1N1 did not. • H1N1pdm viral RNA triggered a stronger response than sH1N1. • H1N1pdm induces greater response due to direct virus–cell interaction. • These results have potential to impact vaccine and therapeutic development

  2. Lessons from the epidemiological surveillance program, during the influenza A (H1N1 virus epidemic, in a reference university hospital of Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Maria Luiza Moretti

    2011-08-01

    Full Text Available INTRODUCTION: The case definition of influenza-like illness (ILI is a powerful epidemiological tool during influenza epidemics. METHODS: A prospective cohort study was conducted to evaluate the impact of two definitions used as epidemiological tools, in adults and children, during the influenza A H1N1 epidemic. Patients were included if they had upper respiratory samples tested for influenza by real-time reverse transcriptase polymerase chain reaction during two periods, using the ILI definition (coughing + temperature > 38ºC in period 1, and the definition of severe acute respiratory infection (ARS (coughing + temperature > 38ºC and dyspnoea in period 2. RESULTS: The study included 366 adults and 147 children, covering 243 cases of ILI and 270 cases of ARS. Laboratory confirmed cases of influenza were higher in adults (50% than in children (21.6% ( p < 0.0001 and influenza infection was more prevalent in the ILI definition (53% than ARS (24.4% (p < 0.0001. Adults reported more chills and myalgia than children (p = 0.0001. Oseltamivir was administered in 58% and 46% of adults and children with influenza A H1N1, respectively. The influenza A H1N1 case fatality rate was 7% in adults and 8.3% in children. The mean time from onset of illness until antiviral administration was 4 days. CONCLUSIONS: The modification of ILI to ARS definition resulted in less accuracy in influenza diagnosis and did not improve the appropriate time and use of antiviral medication.

  3. INFECCIÓN POR VIRUS PANDÉMICO (H1N1 2009 EN ANDALUCÍA

    Directory of Open Access Journals (Sweden)

    José María Mayoral Cortés

    2010-01-01

    Full Text Available Desde que en abril de 2009 la Organización Mundial de la Salud (OMS alertó de la existencia de casos de infección humana por un nuevo virus de la gripe AH1N1 de origen porcino, las autoridades sanitarias de Andalucía activaron un plan específico de actuación para dar respuesta a la crisis sanitaria. Las actividades de vigilancia desarrolladas permitieron disponer de información oportuna sobre las características clínicas, epidemiológicas y virológicas de la enfermedad. En los primeros días se pusieron en marcha planes de contingencia basados en la vigilancia epidemiológica y medidas de control de brotes mediante sistemas de alerta y respuesta rápida. Tras la declaración de fase 6 de alerta pandémica la vigilancia centinela de gripe y de casos graves fueron de utilidad para la planificación de servicios sanitarios, para reducir la transmisión e identificar y para proteger a los grupos de población más vulnerables. El comportamiento de la gripe pandémica en Andalucía ha sido similar al observado en el resto del mundo. La tasa de ataque fue parecida a la de una temporada de gripe estacional y el pico de máxima incidencia se alcanzó en la semana 46/2009. La mayoría de los casos fueron leves y afectó sobre todo a población joven. En los casos hospitalizados la media de edad fue de 32 años. Las patologías previas de base y factores de riesgo mas frecuentes presentes en los casos graves fueron enfermedades pulmonares, tabaquismo y obesidad mórbida (IMC>40. Un escenario de impacto de la onda pandémica en Andalucía, con una tasa de ataque esperada de entre el 2 y 5%, se preparó teniendo en cuenta lo observado durante la onda epidémica en los países del hemisferio sur. Las características de la epidemia en cuanto a su magnitud, gravedad y letalidad, se ajustaron a este escenario utilizado.

  4. Desempeño de la prueba de inmunofluorescencia directa en el diagnóstico del virus Influenza A(H1N1) Direct immunofluorescence assay performance in diagnosis of the Influenza A(H1N1) virus

    OpenAIRE

    Luis Pianciola; Gladys González; Melina Mazzeo; Mariano Navello; Natalia Quidel; María Fernanda Bulgheroni

    2010-01-01

    El 25 de abril de 2009, a menos de un mes de la detección en México del primer humano con virus Influenza A(H1N1), la enfermedad ya se había propagado a más de 40 países superando los 10 000 casos notificados. Dada su naturaleza impredecible, este tipo de virus requiere métodos diagnósticos apropiados, confiables y seguros, pero que también estén al alcance de los laboratorios clínicos. Mediante el estudio de 291 muestras de pacientes con sospecha de infección por virus Influenza A(H1N1) en N...

  5. Temperature sensitivity on growth and/or replication of H1N1, H1N2 and H3N2 influenza A viruses isolated from pigs and birds in mammalian cells.

    Science.gov (United States)

    Massin, Pascale; Kuntz-Simon, Gaëlle; Barbezange, Cyril; Deblanc, Céline; Oger, Aurélie; Marquet-Blouin, Estelle; Bougeard, Stéphanie; van der Werf, Sylvie; Jestin, Véronique

    2010-05-19

    Influenza A viruses have been isolated from a wide range of animal species, aquatic birds being the reservoir for their genetic diversity. Avian influenza viruses can be transmitted to humans, directly or indirectly through an intermediate host like pig. This study aimed to define in vitro conditions that could prove useful to evaluate the potential of influenza viruses to adapt to a different host. Growth of H1N1, H1N2 and H3N2 influenza viruses belonging to different lineages isolated from birds or pigs prior to 2005 was tested on MDCK or NPTr cell lines in the presence or absence of exogenous trypsin. Virus multiplication was compared at 33, 37 and 40 degrees C, the infection site temperatures in human, swine and avian hosts, respectively. Temperature sensitivity of PB2-, NP- and M-RNA replication was also tested by quantitative real-time PCR. Multiplication of avian viruses was cold-sensitive, whatever cell type. By contrast, temperature sensitivity of swine viruses was found to depend on the virus and the host cell: for an H1N1 swine isolate from 1982, multiplication was cold-sensitive on NPTr cells and undetectable at 40 degrees C. From genetic analyses, it appears that temperature sensitivity could involve other residues than PB2 residue 627 and could affect other steps of the replication cycle than replication. Copyright 2009 Elsevier B.V. All rights reserved.

  6. Novel triple reassortant H1N2 influenza viruses bearing six internal genes of the pandemic 2009/H1N1 influenza virus were detected in pigs in China.

    Science.gov (United States)

    Qiao, Chuanling; Liu, Liping; Yang, Huanliang; Chen, Yan; Xu, Huiyang; Chen, Hualan

    2014-12-01

    The pandemic A/H1N1 influenza viruses emerged in both Mexico and the United States in March 2009, and were transmitted efficiently in the human population. Transmissions of the pandemic 2009/H1N1 virus from humans to poultry and other species of mammals were reported from several continents during the course of the 2009 H1N1 pandemic. Reassortant H1N1, H1N2, and H3N2 viruses containing genes of the pandemic 2009/H1N1 viruses appeared in pigs in some countries. In winter of 2012, a total of 2600 nasal swabs were collected from healthy pigs in slaughterhouses located throughout 10 provinces in China. The isolated viruses were subjected to genetic and antigenic analysis. Two novel triple-reassortant H1N2 influenza viruses were isolated from swine in China in 2012, with the HA gene derived from Eurasian avian-like swine H1N1, the NA gene from North American swine H1N2, and the six internal genes from the pandemic 2009/H1N1 viruses. The two viruses had similar antigenic features and some significant changes in antigenic characteristics emerged when compared to the previously identified isolates. We inferred that the novel reassortant viruses in China may have arisen from the accumulation of the three types of influenza viruses, which further indicates that swine herds serve as "mixing vessels" for influenza viruses. Influenza virus reassortment is an ongoing process, and our findings highlight the urgent need for continued influenza surveillance among swine herds. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Virulent PB1-F2 residues: effects on fitness of H1N1 influenza A virus in mice and changes during evolution of human influenza A viruses.

    Science.gov (United States)

    Alymova, Irina V; McCullers, Jonathan A; Kamal, Ram P; Vogel, Peter; Green, Amanda M; Gansebom, Shane; York, Ian A

    2018-05-10

    Specific residues of influenza A virus (IAV) PB1-F2 proteins may enhance inflammation or cytotoxicity. In a series of studies, we evaluated the function of these virulence-associated residues in the context of different IAV subtypes in mice. Here, we demonstrate that, as with the previously assessed pandemic 1968 (H3N2) IAV, PB1-F2 inflammatory residues increase the virulence of H1N1 IAV, suggesting that this effect might be a universal feature. Combining both inflammatory and cytotoxic residues in PB1-F2 enhanced virulence further, compared to either motif alone. Residues from these virulent motifs have been present in natural isolates from human seasonal IAV of all subtypes, but there has been a trend toward a gradual reduction in the number of virulent residues over time. However, human IAV of swine and avian origin tend to have more virulent residues than do the human-adapted seasonal strains, raising the possibility that donation of PB1 segments from these zoonotic viruses may increase the severity of some seasonal human strains. Our data suggest the value of surveillance of virulent residues in both human and animal IAV to predict the severity of influenza season.

  8. Identification of single amino acid substitutions (SAAS) in neuraminidase from influenza a virus (H1N1) via mass spectrometry analysis coupled with de novo peptide sequencing.

    Science.gov (United States)

    Peng, Qisheng; Wang, Zijian; Wu, Donglin; Li, Xiaoou; Liu, Xiaofeng; Sun, Wanchun; Liu, Ning

    2016-08-01

    Amino acid substitutions in the neuraminidase of the influenza virus are the main cause of the emergence of resistance to zanamivir or oseltamivir during seasonal influenza treatment; they are the result of non-synonymous mutations in the viral genome that can be successfully detected by polymer chain reaction (PCR)-based approaches. There is always an urgent need to detect variation in amino acid sequences directly at the protein level. Mass spectrometry coupled with de novo sequencing has been explored as an alternative and straightforward strategy for detecting amino acid substitutions, as well - this approach is the primary focus of the present study. Influenza virus (A/Puerto Rico/8/1934 H1N1) propagated in embryonated chicken eggs was purified by ultracentrifugation, followed by PNGase F treatment. The deglycosylated virion was lysed and separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The gel band corresponding to neuraminidase was picked up and subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. LC-MS/MS analyses, coupled with manual de novo sequencing, allowed the determination of three amino acid substitutions: R346K, S349 N, and S370I/L, in the neuraminidase from the influenza virus (A/Puerto Rico/8/1934 H1N1), which were located in three mutated peptides of the neuraminidase: YGNGVWIGK, TKNHSSR, and PNGWTETDI/LK, respectively. We found that the amino acid substitutions in the proteins of RNA viruses (including influenza A virus) resulting from non-synonymous gene mutations can indeed be directly analyzed via mass spectrometry, and that manual interpretation of the MS/MS data may be beneficial. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Identification of cross-reacting T-cell epitopes in structural and non-structural proteins of swine and pandemic H1N1 influenza A virus strains in pigs

    DEFF Research Database (Denmark)

    Baratelli, Massimiliano; Pedersen, Lasse Eggers; Trebbien, Ramona

    2017-01-01

    Heterologous protection against swine influenza viruses (SwIVs) of different lineages is an important concern for the pig industry. Cross-protection between 'avian-like' H1N1 and 2009 pandemic H1N1 lineages has been observed previously, indicating the involvement of cross-reacting T-cells. Here...

  10. The comparative clinical course of pregnant and non-pregnant women hospitalised with influenza A(H1N1pdm09 infection.

    Directory of Open Access Journals (Sweden)

    Gayle P Dolan

    Full Text Available The Influenza Clinical Information Network (FLU-CIN was established to gather detailed clinical and epidemiological information about patients with laboratory confirmed A(H1N1pdm09 infection in UK hospitals. This report focuses on the clinical course and outcomes of infection in pregnancy.A standardised data extraction form was used to obtain detailed clinical information from hospital case notes and electronic records, for patients with PCR-confirmed A(H1N1pdm09 infection admitted to 13 sentinel hospitals in five clinical 'hubs' and a further 62 non-sentinel hospitals, between 11th May 2009 and 31st January 2010.Outcomes were compared for pregnant and non-pregnant women aged 15-44 years, using univariate and multivariable techniques.Of the 395 women aged 15-44 years, 82 (21% were pregnant; 73 (89% in the second or third trimester. Pregnant women were significantly less likely to exhibit severe respiratory distress at initial assessment (OR = 0.49 (95% CI: 0.30-0.82, require supplemental oxygen on admission (OR = 0.40 (95% CI: 0.20-0.80, or have underlying co-morbidities (p-trend <0.001. However, they were equally likely to be admitted to high dependency (Level 2 or intensive care (Level 3 and/or to die, after adjustment for potential confounders (adj. OR = 0.93 (95% CI: 0.46-1.92. Of 11 pregnant women needing Level 2/3 care, 10 required mechanical ventilation and three died.Since the expected prevalence of pregnancy in the source population was 6%, our data suggest that pregnancy greatly increased the likelihood of hospital admission with A(H1N1pdm09. Pregnant women were less likely than non-pregnant women to have respiratory distress on admission, but severe outcomes were equally likely in both groups.

  11. Acceptance and tolerability of an adjuvanted nH1N1 vaccine in HIV-infected patients in the cologne-bonn cohort

    Directory of Open Access Journals (Sweden)

    Steffens B

    2011-07-01

    Full Text Available Abstract Objective To evaluate the acceptance and tolerability of the nH1N1 2009 vaccine in HIV-positive individuals. Method 758 patients were included in this prospective study. Different study populations were formed: The Tolerability Study Group consists of HIV-infected patients who visited three outpatient clinics (Cologne, Bonn, Freiburg during a predefined time period. Patients were offered nH1N1 vaccination. Those accepting were administered a standard dose AS03 adjuvant nH1N1 vaccine. Questionnaires to report side effects occurring within 7 days after immunization were handed out. In a substudy conducted during the same time period, acceptance towards immunization was recorded. This Acceptance Study Group consists of all HIV-infected patients visiting the Cologne clinic. They were offered vaccination. In case of refusal, motivation was recorded. Results In the Tolerability Study Group, a total of 475 patient diaries returned in the three study centres could be evaluated, 119 of those (25% reported no side effects. Distribution of symptoms was as follows: Pain 285/475 patients (60%, swelling 96 (20%, redness 54 (11%, fever 48/475 (10%, muscle/joint ache 173 (36%, headache 127 (27%, and fatigue 210 (44%. Association of side effects with clinical data was calculated for patients in Cologne and Bonn. Incidence of side effects was significantly associated with CDC stages A, B compared to C, and with a detectable viral load (> 50 copies/mL. No correlation was noted for CD4 cell count, age, gender or ethnicity. In the Acceptance Study Group, 538 HIV-infected patients were offered vaccination, 402 (75% accepted, while 136 (25% rejected. Main reasons for rejection were: Negative media coverage (35%, indecisiveness with preference to wait until a later date (23%, influenza not seen as personal threat (19% and scepticism towards immunization in general (10%. Conclusion A total of 622 HIV-infected patients were vaccinated against nH1N1-influenza in

  12. Identification of Low- and High-Impact Hemagglutinin Amino Acid Substitutions That Drive Antigenic Drift of Influenza A(H1N1 Viruses.

    Directory of Open Access Journals (Sweden)

    William T Harvey

    2016-04-01

    Full Text Available Determining phenotype from genetic data is a fundamental challenge. Identification of emerging antigenic variants among circulating influenza viruses is critical to the vaccine virus selection process, with vaccine effectiveness maximized when constituents are antigenically similar to circulating viruses. Hemagglutination inhibition (HI assay data are commonly used to assess influenza antigenicity. Here, sequence and 3-D structural information of hemagglutinin (HA glycoproteins were analyzed together with corresponding HI assay data for former seasonal influenza A(H1N1 virus isolates (1997-2009 and reference viruses. The models developed identify and quantify the impact of eighteen amino acid substitutions on the antigenicity of HA, two of which were responsible for major transitions in antigenic phenotype. We used reverse genetics to demonstrate the causal effect on antigenicity for a subset of these substitutions. Information on the impact of substitutions allowed us to predict antigenic phenotypes of emerging viruses directly from HA gene sequence data and accuracy was doubled by including all substitutions causing antigenic changes over a model incorporating only the substitutions with the largest impact. The ability to quantify the phenotypic impact of specific amino acid substitutions should help refine emerging techniques that predict the evolution of virus populations from one year to the next, leading to stronger theoretical foundations for selection of candidate vaccine viruses. These techniques have great potential to be extended to other antigenically variable pathogens.

  13. Identification of Low- and High-Impact Hemagglutinin Amino Acid Substitutions That Drive Antigenic Drift of Influenza A(H1N1) Viruses

    Science.gov (United States)

    Harvey, William T.; Benton, Donald J.; Gregory, Victoria; Hall, James P. J.; Daniels, Rodney S.; Bedford, Trevor; Haydon, Daniel T.; Hay, Alan J.; McCauley, John W.; Reeve, Richard

    2016-01-01

    Determining phenotype from genetic data is a fundamental challenge. Identification of emerging antigenic variants among circulating influenza viruses is critical to the vaccine virus selection process, with vaccine effectiveness maximized when constituents are antigenically similar to circulating viruses. Hemagglutination inhibition (HI) assay data are commonly used to assess influenza antigenicity. Here, sequence and 3-D structural information of hemagglutinin (HA) glycoproteins were analyzed together with corresponding HI assay data for former seasonal influenza A(H1N1) virus isolates (1997–2009) and reference viruses. The models developed identify and quantify the impact of eighteen amino acid substitutions on the antigenicity of HA, two of which were responsible for major transitions in antigenic phenotype. We used reverse genetics to demonstrate the causal effect on antigenicity for a subset of these substitutions. Information on the impact of substitutions allowed us to predict antigenic phenotypes of emerging viruses directly from HA gene sequence data and accuracy was doubled by including all substitutions causing antigenic changes over a model incorporating only the substitutions with the largest impact. The ability to quantify the phenotypic impact of specific amino acid substitutions should help refine emerging techniques that predict the evolution of virus populations from one year to the next, leading to stronger theoretical foundations for selection of candidate vaccine viruses. These techniques have great potential to be extended to other antigenically variable pathogens. PMID:27057693

  14. Influenza A (H1N1) pneumonia: HRCT findings

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, Viviane Brandao; Rodrigues, Rosana Souza; Barreto, Miriam Menna; Marchiori, Edson, E-mail: edmarchiori@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Zanetti, Glaucia [Escola de Medicina de Petropolis, RJ (Brazil); Hochhegger, Bruno [Santa Casa de Misericordia de Porto Alegre, RS (Brazil)

    2013-11-01

    Objective: to describe aspects found on HRCT scans of the chest in patients infected with the influenza A (H1N1) virus. Methods: we retrospectively analyzed the HRCT scans of 71 patients (38 females and 33 males) with H1N1 infection, confirmed through laboratory tests, between July and September of 2009. The HRCT scans were interpreted by two thoracic radiologists independently, and in case of disagreement, the decisions were made by consensus. Results: the most common HRCT findings were ground-glass opacities (85%), consolidation (64%), or a combination of ground-glass opacities and consolidation (58%). Other findings were airspace nodules (25%), bronchial wall thickening (25%), interlobular septal thickening (21%), crazy-paving pattern (15%), perilobular pattern (3%), and air trapping (3%). The findings were frequently bilateral (89%), with a random distribution (68%). Pleural effusion, when observed, was typically minimal. No lymphadenopathy was identified. Conclusions: the most common findings were ground-glass opacities and consolidations, or a combination of both. Involvement was commonly bilateral with no axial or cranio caudal predominance in the distribution. Although the major tomographic findings in H1N1 infection are nonspecific, it is important to recognize such findings in order to include infection with the H1N1 virus in the differential diagnosis of respiratory symptoms. (author)

  15. Clinical differences between H3N2 and H1N1 influenza 2012 and lower respiratory tract infection found using a statistical classification approach

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    Petridis D

    2014-02-01

    drug for only for 1 day, 19 patients for 5 days, and 8 patients from 2 to 10 days. Conclusion: Clusters of symptoms can be used to identify different types of influenza and disease severity. Patients with vaccination had pneumonia, whereas patients without vaccination had influenza A. Patients more than 54.5 years old had H3N2 and patients less than 54.5 years had H1N1. White blood cell count values increased from normal to elevated in H3N2 patients but still remained abnormal in lower tract infection and H1N1 patients. Keywords: H3N2, H1N1, influenza outbreak, respiratory infection, vaccination

  16. Influenza A(H1N1)pdm09 in critically ill children admitted to a ...

    African Journals Online (AJOL)

    tes. Fig. 1. The prevalence of seasonal and pandemic H1N1 (pH1N1) influenza A at RCWMCH and ... Full approval for the study was obtained from the Human Research ... respiratory virus infection, had not received prophylactic oseltamivir,.

  17. [Differences in oligomerization of nucleocapsid protein of epidemic human influenza A(H1N1), A(H1N2) and B viruses].

    Science.gov (United States)

    Prokudina, E N; Semenova, N P; Chumakov, V M; Burtseva, E I; Slepushkin, A N

    2003-01-01

    A comparative analysis of involving the nucleocapsid protein (NP) into shaping-up of SDS-resistant oligomers was carried out presently in circulating epidemic strains of human influenza, viruses A and B. The study results of viral isolates obtained from clinical samples and recent standard strains revealed that the involvement of NP in the SDS-resistant oligomers, which are different in various subtypes of influenza A viruses. According to this sign, the human viruses A(9H3N2) are close to the avian ones, in which, as proved by us previously, virtually the entire NP transforms itself into the oligomers resistant to SDS. About 10-20% of NP are involved in shaping-up the virus influenza A(H1N1) of SDS-resistant oligomers. No SDS-resistant NP-oligomers were detected in influenza of type B. It is suggested that the prevalence of human viruses A(H3N2) in NP-oligomers are the peculiarities of NP structure and of the presence of the PB1 protein from avian influenza virus.

  18. EVOLUCIÓN DE LA PANDEMIA POR EL VIRUS DE LA GRIPE (H1N1 2009 EN LA COMUNIDAD AUTÓNOMA DE LA RIOJA

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    Eva María Martínez Ochoa

    2010-01-01

    Full Text Available Fundamento. El objetivo de este estudio ha sido realizar un análisis de la evolución de la pandemia por el virus de la gripe (H1N1 2009 en la Comunidad Autónoma de La Rioja tanto en atención primaria como en hospitalaria. Métodos. El periodo de estudio incluyó desde la semana 28- 2009 hasta la 3-2010. La información de los casos de gripe se obtuvo de las bases informatizadas de atención primaria (OMI, de los listados remitidos por los servicios hospitalarios de medicina preventiva, del laboratorio de referencia de La Rioja y de los formularios de notificación individual. Se realizó una descripción de los casos según distribución por semana, sexo, edad, factores de riesgo, evolución y complicaciones. Se utilizó la regresión binaria logística para estimar las odds ratios ajustadas y su intervalo de confianza al 95%, de recibir tratamiento antiviral según factores de riesgo. Resultados. Hasta la semana epidemiológica 3 de 2010 se declararon a través del sistema OMI de atención primaria 7.096 casos de sospecha de gripe (H1N1 2009, fueron hospitalizados 111 casos con diagnóstico confirmado por laboratorio. Requirieron atención en cuidados intensivos 5 (4,5% y 2 fallecieron. Todos ellos presentaban factores de riesgo. Ninguno de los niños ni de las mujeres embarazadas hospitalizados precisaron ingreso en cuidados intensivos. Conclusiones. Durante la pandemia la gripe (H1N1 2009 fue una enfermedad propia de la población pediátrica y joven, apareciendo con menor frecuencia en las personas mayores de 60 años. La evolución clínica en La Rioja cursó de forma leve en la mayoría de las personas diagnosticados.

  19. Molecular and antigenic characterization of reassortant H3N2 viruses from turkeys with a unique constellation of pandemic H1N1 internal genes.

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    Yohannes Berhane

    Full Text Available Triple reassortant (TR H3N2 influenza viruses cause varying degrees of loss in egg production in breeder turkeys. In this study we characterized TR H3N2 viruses isolated from three breeder turkey farms diagnosed with a drop in egg production. The eight gene segments of the virus isolated from the first case submission (FAV-003 were all of TR H3N2 lineage. However, viruses from the two subsequent case submissions (FAV-009 and FAV-010 were unique reassortants with PB2, PA, nucleoprotein (NP and matrix (M gene segments from 2009 pandemic H1N1 and the remaining gene segments from TR H3N2. Phylogenetic analysis of the HA and NA genes placed the 3 virus isolates in 2 separate clades within cluster IV of TR H3N2 viruses. Birds from the latter two affected farms had been vaccinated with a H3N4 oil emulsion vaccine prior to the outbreak. The HAl subunit of the H3N4 vaccine strain had only a predicted amino acid identity of 79% with the isolate from FAV-003 and 80% for the isolates from FAV-009 and FAV-0010. By comparison, the predicted amino acid sequence identity between a prototype TR H3N2 cluster IV virus A/Sw/ON/33853/2005 and the three turkey isolates from this study was 95% while the identity between FAV-003 and FAV-009/10 isolates was 91%. When the previously identified antigenic sites A, B, C, D and E of HA1 were examined, isolates from FAV-003 and FAV-009/10 had a total of 19 and 16 amino acid substitutions respectively when compared with the H3N4 vaccine strain. These changes corresponded with the failure of the sera collected from turkeys that received this vaccine to neutralize any of the above three isolates in vitro.

  20. What happened after the initial global spread of pandemic human influenza virus A (H1N1? A population genetics approach

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    Martinez-Hernandez Fernando

    2010-08-01

    Full Text Available Abstract Viral population evolution dynamics of influenza A is crucial for surveillance and control. In this paper we analyzed viral genetic features during the recent pandemic caused by the new influenza human virus A H1N1, using a conventional population genetics approach based on 4689 hemagglutinin (HA and neuraminidase (NA sequences available in GenBank submitted between March and December of 2009. This analysis showed several relevant aspects: a a scarce initial genetic variability within the viral isolates from some countries that increased along 2009 when influenza was dispersed around the world; b a worldwide virus polarized behavior identified when comparing paired countries, low differentiation and high gene flow were found in some pairs and high differentiation and moderate or scarce gene flow in others, independently of their geographical closeness, c lack of positive selection in HA and NA due to increase of the population size of virus variants, d HA and NA variants spread in a few months all over the world being identified in the same countries in different months along 2009, and e containment of viral variants in Mexico at the beginning of the outbreak, probably due to the control measures applied by the government.

  1. Treatment and Prevention of Pandemic H1N1 Influenza.

    Science.gov (United States)

    Rewar, Suresh; Mirdha, Dashrath; Rewar, Prahlad

    2015-01-01

    Swine influenza is a respiratory infection common to pigs worldwide caused by type A influenza viruses, principally subtypes H1N1, H1N2, H2N1, H3N1, H3N2, and H2N3. Swine influenza viruses also can cause moderate to severe illness in humans and affect persons of all age groups. People in close contact with swine are at especially high risk. Until recently, epidemiological study of influenza was limited to resource-rich countries. The World Health Organization declared an H1N1 pandemic on June 11, 2009, after more than 70 countries reported 30,000 cases of H1N1 infection. In 2015, incidence of swine influenza increased substantially to reach a 5-year high. In India in 2015, 10,000 cases of swine influenza were reported with 774 deaths. The Centers for Disease Control and Prevention recommend real-time polymerase chain reaction as the method of choice for diagnosing H1N1. Antiviral drugs are the mainstay of clinical treatment of swine influenza and can make the illness milder and enable the patient to feel better faster. Antiviral drugs are most effective when they are started within the first 48 hours after the clinical signs begin, although they also may be used in severe or high-risk cases first seen after this time. The Centers for Disease Control and Prevention recommends use of oseltamivir (Tamiflu, Genentech) or zanamivir (Relenza, GlaxoSmithKline). Prevention of swine influenza has 3 components: prevention in swine, prevention of transmission to humans, and prevention of its spread among humans. Because of limited treatment options, high risk for secondary infection, and frequent need for intensive care of individuals with H1N1 pneumonia, environmental control, including vaccination of high-risk populations and public education are critical to control of swine influenza out breaks. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Enhanced pneumonia and disease in pigs vaccinated with an inactivated human-like (δ-cluster) H1N2 vaccine and challenged with pandemic 2009 H1N1 influenza virus.

    Science.gov (United States)

    Gauger, Phillip C; Vincent, Amy L; Loving, Crystal L; Lager, Kelly M; Janke, Bruce H; Kehrli, Marcus E; Roth, James A

    2011-03-24

    Influenza is an economically important respiratory disease affecting swine world-wide with potential zoonotic implications. Genetic reassortment and drift has resulted in genetically and antigenically distinct swine influenza viruses (SIVs). Consequently, prevention of SIV infection is challenging due to the increased rate of genetic change and a potential lack of cross-protection between vaccine strains and circulating novel isolates. This report describes a vaccine-heterologous challenge model in which pigs were administered an inactivated H1N2 vaccine with a human-like (δ-cluster) H1 six and three weeks before challenge with H1 homosubtypic, heterologous 2009 pandemic H1N1. At necropsy, macroscopic and microscopic pneumonia scores were significantly higher in the vaccinated and challenged (Vx/Ch) group compared to non-vaccinated and challenged (NVx/Ch) pigs. The Vx/Ch group also demonstrated enhanced clinical disease and a significantly elevated pro-inflammatory cytokine profile in bronchoalveolar lavage fluid compared to the NVx/Ch group. In contrast, viral shedding and replication were significantly higher in NVx/Ch pigs although all challenged pigs, including Vx/Ch pigs, were shedding virus in nasal secretions. Hemagglutination inhibition (HI) and serum neutralizing (SN) antibodies were detected to the priming antigen in the Vx/Ch pigs but no measurable cross-reacting HI or SN antibodies were detected to pandemic H1N1 (pH1N1). Overall, these results suggest that inactivated SIV vaccines may potentiate clinical signs, inflammation and pneumonia following challenge with divergent homosubtypic viruses that do not share cross-reacting HI or SN antibodies. Published by Elsevier Ltd.

  3. Predominance of influenza A(H1N1)pdm09 virus genetic subclade 6B.1 and influenza B/Victoria lineage viruses at the start of the 2015/16 influenza season in Europe

    DEFF Research Database (Denmark)

    Broberg, Eeva; Melidou, Angeliki; Prosenc, Katarina

    2016-01-01

    Influenza A(H1N1)pdm09 viruses predominated in the European influenza 2015/16 season. Most analysed viruses clustered in a new genetic subclade 6B.1, antigenically similar to the northern hemisphere vaccine component A/California/7/2009. The predominant influenza B lineage was Victoria compared...

  4. Anti-viral properties and mode of action of standardized Echinacea purpurea extract against highly pathogenic avian Influenza virus (H5N1, H7N7 and swine-origin H1N1 (S-OIV

    Directory of Open Access Journals (Sweden)

    Schoop Roland

    2009-11-01

    Full Text Available Abstract Background Influenza virus (IV infections are a major threat to human welfare and animal health worldwide. Anti-viral therapy includes vaccines and a few anti-viral drugs. However vaccines are not always available in time, as demonstrated by the emergence of the new 2009 H1N1-type pandemic strain of swine origin (S-OIV in April 2009, and the acquisition of resistance to neuraminidase inhibitors such as Tamiflu® (oseltamivir is a potential problem. Therefore the prospects for the control of IV by existing anti-viral drugs are limited. As an alternative approach to the common anti-virals we studied in more detail a commercial standardized extract of the widely used herb Echinacea purpurea (Echinaforce®, EF in order to elucidate the nature of its anti-IV activity. Results Human H1N1-type IV, highly pathogenic avian IV (HPAIV of the H5- and H7-types, as well as swine origin IV (S-OIV, H1N1, were all inactivated in cell culture assays by the EF preparation at concentrations ranging from the recommended dose for oral consumption to several orders of magnitude lower. Detailed studies with the H5N1 HPAIV strain indicated that direct contact between EF and virus was required, prior to infection, in order to obtain maximum inhibition in virus replication. Hemagglutination assays showed that the extract inhibited the receptor binding activity of the virus, suggesting that the extract interferes with the viral entry into cells. In sequential passage studies under treatment in cell culture with the H5N1 virus no EF-resistant variants emerged, in contrast to Tamiflu®, which produced resistant viruses upon passaging. Furthermore, the Tamiflu®-resistant virus was just as susceptible to EF as the wild type virus. Conclusion As a result of these investigations, we believe that this standard Echinacea preparation, used at the recommended dose for oral consumption, could be a useful, readily available and affordable addition to existing control options

  5. Rapid spread of influenza A(H1N1)pdm09 viruses with a new set of specific mutations in the internal genes in the beginning of 2015/2016 epidemic season in Moscow and Saint Petersburg (Russian Federation).

    Science.gov (United States)

    Komissarov, Andrey; Fadeev, Artem; Sergeeva, Maria; Petrov, Sergey; Sintsova, Kseniya; Egorova, Anna; Pisareva, Maria; Buzitskaya, Zhanna; Musaeva, Tamila; Danilenko, Daria; Konovalova, Nadezhda; Petrova, Polina; Stolyarov, Kirill; Smorodintseva, Elizaveta; Burtseva, Elena; Krasnoslobodtsev, Kirill; Kirillova, Elena; Karpova, Lyudmila; Eropkin, Mikhail; Sominina, Anna; Grudinin, Mikhail

    2016-07-01

    A dramatic increase of influenza activity in Russia since week 3 of 2016 significantly differs from previous seasons in terms of the incidence of influenza and acute respiratory infection (ARI) and in number of lethal cases. We performed antigenic analysis of 108 and whole-genome sequencing of 77 influenza A(H1N1)pdm09 viruses from Moscow and Saint Petersburg. Most of the viruses were antigenically related to the vaccine strain. Whole-genome analysis revealed a composition of specific mutations in the internal genes (D2E and M83I in NEP, E125D in NS1, M105T in NP, Q208K in M1, and N204S in PA-X) that probably emerged before the beginning of 2015/2016 epidemic season. © 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  6. Altered specificity of single-chain antibody fragments bound to pandemic H1N1-2009 influenza virus after conversion of the phage-bound to the soluble form

    Directory of Open Access Journals (Sweden)

    Kaku Yoshihiro

    2012-09-01

    Full Text Available Abstract Background In 2009, a novel influenza A/H1N1 virus (H1N1pdm quickly spread worldwide and co-circulated with then-existing seasonal H1N1 virus (sH1N1. Distinguishing between these 2 viruses was necessary to better characterize the epidemiological properties of the emergent virus, including transmission patterns, pathogenesis, and anti-influenza drug resistance. This situation prompted us to develop a point-of-care virus differentiation system before entering the 2009–2010 influenza season. Aiming to establish H1N1pdm-specific detection tools rapidly, we employed phage display libraries to select H1N1pdm-specific single-chain variable fragments (scFvs. Findings Human single-fold scFv libraries (Tomlinson I + J underwent selection for the ability to bind H1N1pdm virus particles. Three rounds of panning brought 1152 phage-bound scFvs, of which 58 clones reacted with H1N1pdm specifically or preferentially over sH1N1 in an enzyme-linked immunosorbent assay (ELISA. After conversion of the scFvs to soluble form, 7 clones demonstrating high/stable expression were finally obtained. However, all the soluble scFvs except No. 29 were found to have lost their specificity/preference for H1N1pdm in ELISA. The specificity/preference of No. 29 was also confirmed by immunofluorescence assay and immunoprecipitation, and the viral nucleoprotein was identified by ELISA as its target protein. The change in specificity associated with scFv conversion from phage-bound to soluble form could be due to loss of phage scaffold pIII protein, which likely provides structural support for the scFv antigen-binding site. It is also possible that the similar antigenic properties of H1N1pdm and sH1N1 led to the observed alterations in scFv specificity. Discussion Using a phage display library, we obtained 7 soluble scFv clones reactive against H1N1pdm; however, only 1 showed specificity/preference toward H1N1pdm. Our results confirmed that using phage display

  7. Screening of random peptide library of hemagglutinin from pandemic 2009 A(H1N1 influenza virus reveals unexpected antigenically important regions.

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    Wanghui Xu

    Full Text Available The antigenic structure of the membrane protein hemagglutinin (HA from the 2009 A(H1N1 influenza virus was dissected with a high-throughput screening method using complex antisera. The approach involves generating yeast cell libraries displaying a pool of random peptides of controllable lengths on the cell surface, followed by one round of fluorescence-activated cell sorting (FACS against antisera from mouse, goat and human, respectively. The amino acid residue frequency appearing in the antigenic peptides at both the primary sequence and structural level was determined and used to identify "hot spots" or antigenically important regions. Unexpectedly, different antigenic structures were seen for different antisera. Moreover, five antigenic regions were identified, of which all but one are located in the conserved HA stem region that is responsible for membrane fusion. Our findings are corroborated by several recent studies on cross-neutralizing H1 subtype antibodies that recognize the HA stem region. The antigenic peptides identified may provide clues for creating peptide vaccines with better accessibility to memory B cells and better induction of cross-neutralizing antibodies than the whole HA protein. The scheme used in this study enables a direct mapping of the antigenic regions of viral proteins recognized by antisera, and may be useful for dissecting the antigenic structures of other viral proteins.

  8. Effectiveness of the AS03-adjuvanted vaccine against pandemic influenza virus A/(H1N1 2009--a comparison of two methods; Germany, 2009/10.

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    Helmut Uphoff

    Full Text A