WorldWideScience

Sample records for choriomeningitis virus infection

  1. Congenital Viral Infections of the Brain: Lessons Learned from Lymphocytic Choriomeningitis Virus in the Neonatal Rat

    OpenAIRE

    Bonthius, Daniel J.; Stanley Perlman

    2007-01-01

    The fetal brain is highly vulnerable to teratogens, including many infectious agents. As a consequence of prenatal infection, many children suffer severe and permanent brain injury and dysfunction. Because most animal models of congenital brain infection do not strongly mirror human disease, the models are highly limited in their abilities to shed light on the pathogenesis of these diseases. The animal model for congenital lymphocytic choriomeningitis virus (LCMV) infection, however, does not...

  2. Studies on the role of mononuclear phagocytes in resistance to acute lymphocytic choriomeningitis virus infection

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Volkert, M

    1983-01-01

    The role of mononuclear phagocytes in various phases of the acute lymphocytic choriomeningitis virus (LCMV) infection was studied. The anti-macrophage agent carrageenan delayed virus clearance. Carrageenan was most effective when given before virus inoculation, suggesting that it interfered...... with early events in the host response to the virus. Correspondingly, carrageenan enhanced early virus multiplication. Pretreatment with carrageenan apparently did not inhibit induction of the T-cell response and had little or no direct effect on T-cell-dependent anti-viral activity. The LCMV-induced natural...

  3. Congenital viral infections of the brain: lessons learned from lymphocytic choriomeningitis virus in the neonatal rat.

    Directory of Open Access Journals (Sweden)

    Daniel J Bonthius

    2007-11-01

    Full Text Available The fetal brain is highly vulnerable to teratogens, including many infectious agents. As a consequence of prenatal infection, many children suffer severe and permanent brain injury and dysfunction. Because most animal models of congenital brain infection do not strongly mirror human disease, the models are highly limited in their abilities to shed light on the pathogenesis of these diseases. The animal model for congenital lymphocytic choriomeningitis virus (LCMV infection, however, does not suffer from this limitation. LCMV is a well-known human pathogen. When the infection occurs during pregnancy, the virus can infect the fetus, and the developing brain is particularly vulnerable. Children with congenital LCMV infection often have substantial neurological deficits. The neonatal rat inoculated with LCMV is a superb model system of human congenital LCMV infection. Virtually all of the neuropathologic changes observed in humans congenitally infected with LCMV, including microencephaly, encephalomalacia, chorioretinitis, porencephalic cysts, neuronal migration disturbances, periventricular infection, and cerebellar hypoplasia, are reproduced in the rat model. Within the developing rat brain, LCMV selectively targets mitotically active neuronal precursors. Thus, the targets of infection and sites of pathology depend on host age at the time of infection. The rat model has further shown that the pathogenic changes induced by LCMV infection are both virus-mediated and immune-mediated. Furthermore, different brain regions simultaneously infected with LCMV can undergo widely different pathologic changes, reflecting different brain region-virus-immune system interactions. Because the neonatal rat inoculated with LCMV so faithfully reproduces the diverse neuropathology observed in the human counterpart, the rat model system is a highly valuable tool for the study of congenital LCMV infection and of all prenatal brain infections In addition, because LCMV

  4. Lymphocytic choriomeningitis virus (LCMV) infection of macaques: a model for Lassa fever.

    Science.gov (United States)

    Zapata, Juan C; Pauza, C David; Djavani, Mahmoud M; Rodas, Juan D; Moshkoff, Dmitry; Bryant, Joseph; Ateh, Eugene; Garcia, Cybele; Lukashevich, Igor S; Salvato, Maria S

    2011-11-01

    Arenaviruses such as Lassa fever virus (LASV) and lymphocytic choriomeningitis virus (LCMV) are benign in their natural reservoir hosts, and can occasionally cause severe viral hemorrhagic fever (VHF) in non-human primates and in human beings. LCMV is considerably more benign for human beings than Lassa virus, however certain strains, like the LCMV-WE strain, can cause severe disease when the virus is delivered as a high-dose inoculum. Here we describe a rhesus macaque model for Lassa fever that employs a virulent strain of LCMV. Since LASV must be studied within Biosafety Level-4 (BSL-4) facilities, the LCMV-infected macaque model has the advantage that it can be used at BSL-3. LCMV-induced disease is rarely as severe as other VHF, but it is similar in cases where vascular leakage leads to lethal systemic failure. The LCMV-infected macaque has been valuable for describing the course of disease with differing viral strains, doses and routes of infection. By monitoring system-wide changes in physiology and gene expression in a controlled experimental setting, it is possible to identify events that are pathognomonic for developing VHF and potential treatment targets. PMID:21820469

  5. Lymphocytic choriomeningitis virus (LCMV) infection of macaques: a model for Lassa fever

    Science.gov (United States)

    Zapata, Juan C.; Pauza, C. David; Djavani, Mahmoud M.; Rodas, Juan D.; Moshkoff, Dmitry; Bryant, Joseph; Ateh, Eugene; Garcia, Cybele; Lukashevich, Igor S.; Salvato, Maria S.

    2011-01-01

    Arenaviruses such as Lassa fever virus (LASV) and lymphocytic choriomeningitis virus (LCMV) are benign in their natural reservoir hosts, and can occasionally cause severe viral hemorrhagic fever (VHF) in non-human primates and in human beings. LCMV is considerably more benign for human beings than Lassa virus, however certain strains, like the LCMV-WE strain, can cause severe disease when the virus is delivered as a high-dose inoculum. Here we describe a rhesus macaque model for Lassa fever that employs a virulent strain of LCMV. Since LASV must be studied within Biosafety Level-4 (BSL-4) facilities, the LCMV-infected macaque model has the advantage that it can be used at BSL-3. LCMV-induced disease is rarely as severe as other VHF, but it is similar in cases where vascular leakage leads to lethal systemic failure. The LCMV-infected macaque has been valuable for describing the course of disease with differing viral strains, doses and routes of infection. By monitoring system-wide changes in physiology and gene expression in a controlled experimental setting, it is possible to identify events that are pathognomonic for developing VHF and potential treatment targets. PMID:21820469

  6. Lymphocytic choriomeningitis virus (LCMV) infection of macaques: a model for Lassa fever

    OpenAIRE

    Zapata, Juan C.; Pauza, C. David; Djavani, Mahmoud M.; Rodas, Juan D.; Moshkoff, Dmitry; Bryant, Joseph; Ateh, Eugene; Garcia, Cybele; Lukashevich, Igor S.; Salvato, Maria S.

    2011-01-01

    Arenaviruses such as Lassa fever virus (LASV) and lymphocytic choriomeningitis virus (LCMV) are benign in their natural reservoir hosts, and can occasionally cause severe viral hemorrhagic fever (VHF) in non-human primates and in human beings. LCMV is considerably more benign for human beings than Lassa virus, however certain strains, like the LCMV-WE strain, can cause severe disease when the virus is delivered as a high-dose inoculum. Here we describe a rhesus macaque model for Lassa fever t...

  7. Vaccination against lymphocytic choriomeningitis virus infection in MHC class II-deficient mice

    DEFF Research Database (Denmark)

    Holst, Peter Johannes; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup

    2011-01-01

    response could be elicited in MHC class II-deficient mice by vaccination with adenovirus encoding lymphocytic choriomeningitis virus (LCMV) glycoprotein tethered to MHC class II-associated invariant chain. Moreover, the response induced conferred significant cytolytic CD8(+) T cell-mediated protection...... against challenge with a high dose of the invasive clone 13 strain of LCMV. In contrast, vaccination with adenovirus encoding unlinked LCMV glycoprotein induced weak virus control in the absence of CD4(+) T cells, and mice may die of increased immunopathology associated with incomplete protection. Acute...

  8. CD8+ T Cell Immunodominance in Lymphocytic Choriomeningitis Virus Infection Is Modified in the Presence of Toll-Like Receptor Agonists ▿

    OpenAIRE

    Siddiqui, Sarah; Basta, Sameh

    2011-01-01

    Currently, we have limited understanding of how Toll-like receptor (TLR) engagement by microbial products influences the immune response during a concurrent virus infection. In this study, we established that dual TLR2 plus TLR3 (designated TLR2+3) stimulation alters the immunodominance hierarchies of lymphocytic choriomeningitis virus (LCMV) epitopes by reducing NP396-specific CD8+ T cell responses and shifting it to a subdominant position. The shift in immunodominance occurred due to a redu...

  9. Mechanisms of lymphocytic choriomeningitis virus-induced hemopoietic dysfunction

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Pisa, P; Bro-Jørgensen, K;

    1986-01-01

    Results of this study showed that lymphocytic choriomeningitis virus infection causes a marked activation of natural killer (NK) cells not only in the spleen but also in the bone marrow. This activity reached its peak at about day 3 of infection and declined after days 6 to 7. Enhanced NK cell...

  10. Persistence of the irradiated host component in thymocyte populations from bone marrow radiation chimeras infected with lymphocytic choriomeningitis virus

    International Nuclear Information System (INIS)

    The thymus of chimeras made using T cell-depleted donor bone marrow from Thy1.1+ mice and 950 rad Thy 1.2+ recipients is dominated initially by cells expressing the Thy 1.2+ phenotype of the irradiated host. The thymocyte population recovered at 2 weeks after reconstitution comprises 80% Thy 1.2+ cells (host), the remainder being Thy 1.1+ (donor). This situation is normally reversed within a further week, with the host Ty 1.2+ (donor). This situation is normally reversed within a further week, with the host Thy 1.2+ thymocytes being present at a frequency of less than 5% from Week 4. Infection with lymphocytic choriomeningitis virus (LCMV) at 1 week after reconstitution with bone marrow causes a profound and persistent drop in the total number of thymocytes. The decline is equivalent for all categories of donor-derived thymocytes defined by two-color flow microfluorometric analysis for CD4 and CD8. However, there is a partial compensation by the retention of cells originating from the Thy 1.2+ host, which constitute 30-40% of the total thymocyte pool as late as 8 weeks after administration of bone marrow in the LCMV-infected chimeras. These radiation-resistant precursors give rise to CD4-8-, CD4-8+, CD4+8-, and CD4+8+ thymocytes, with the latter category being present at increased frequency. The potential skewing of the mature T cell repertoire as a consequence of persistent virus infection is discussed

  11. High-dose survival in the lymphocytic choriomeningitis virus infection is accompanied by suppressed DTH but unaffected T-cell cytotoxicity

    DEFF Research Database (Denmark)

    Marker, O; Thomsen, Allan Randrup; Volkert, M;

    1985-01-01

    Provided that intracerebral inoculation is applied, an increase in the virus dose from 10(2) to 10(4) LD50 of lymphocytic choriomeningitis virus (LCMV) leads to strikingly reduced mortality. To analyse the background for this autointerference, we measured several virologic and immunologic variables...... intracerebral infection with large and small virus doses, and since the LCMV infection in the brain qualitatively and quantitatively was independent of the size of virus inoculum, the explanation for the survival of the high-dose animals is obviously not lack of possibilities for interaction between cytotoxic T...... cells and infected sensitive targets in the central nervous system. On the other hand, high doses of virus caused a clear suppression of the LCMV-specific delayed-type hypersensitivity (DTH). In addition, when splenocytes from high-dose animals were transferred either intravenously or locally...

  12. Different Tc response profiles are associated with survival in the murine lymphocytic choriomeningitis virus infection

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Marker, O; Pfau, C J

    1987-01-01

    was found despite a mortality rate of only 10-20%. Similarly, in C3H mice inoculated with the aggressive and docile substrains of UBC strain LCMV, which differ markedly in their pathogenicity for this mouse strain, similar kinetics of Tc induction were observed. Finally, in DBA/2 mice which do not die...... following infection with the otherwise lethal aggressive substrain, Tc induction could be found to be as efficient as in BALB/c mice, all of which die from acute LCM disease when infected with this virus isolate. The results indicate, therefore, that early and high Tc activity does not constitute...... a sufficient prerequisite for lethal disease, and that different Tc response profiles may be associated with low mortality following i.c. inoculation with LCMV....

  13. Fatal meningitis following lymphocytic choriomeningitis virus infection reflects delayed-type hypersensitivity rather than cytotoxicity

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Bro-Jørgensen, K; Volkert, M

    1983-01-01

    to be the result of a Cy-induced lack of non-committed ancillary cells since: (1) virus-primed spleen cells from Cy-pretreated donors conferred normal LCMV-specific DTH to naive recipients; (2) transfer of virus-primed spleen cells from untreated donors did not increase the suppressed DTH response of the Cy...

  14. Virus elimination in acute lymphocytic choriomeningitis virus infection. Correlation with virus-specific delayed-type hypersensitivity rather than cytotoxicity

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Volkert, M; Bro-Jørgensen, K

    1983-01-01

    correlation between the host's ability to mount a virus-specific delayed-type hypersensitivity (DTH) response and its capacity to combat virus. Moreover, pretreatment with silica and carrageenan prolonged viraemia without impairment of the peak Tc-cell response. These findings indicate that Tc cells have...

  15. [Incidence and features of neuroinfections induced by lymphocytic choriomeningitis virus].

    Science.gov (United States)

    Dekonenko, E P; Tkachenko, E A; Umanskiĭ, K G; Ivanov, A P; Rezapkin, G V

    1986-01-01

    A follow-up examination of blood sera and cerebrospinal fluid was carried out in 413 patients with various neuroinfections and related diseases. The modern immunological methods were employed: the complement fixation test, the fluorescent antibody test as well as immuno-enzymic and radioimmunoassays. It was established that 8.5% of serous meningitides and 12% of encephalitides were induced by lymphocytic choriomeningitis (LCM) virus. The verified diseases were subjected to a clinical analysis. It is emphasized that the immunological examination of the cerebrospinal fluid in patients with LCM infection contributes to a more detailed study of the pathogenesis of the disease.

  16. Cell entry of lymphocytic choriomeningitis virus is restricted in myotubes.

    Science.gov (United States)

    Iwasaki, Masaharu; Urata, Shuzo; Cho, Yoshitake; Ngo, Nhi; de la Torre, Juan C

    2014-06-01

    In mice persistently infected since birth with the prototypic arenavirus lymphocytic choriomeningitis viurs, viral antigen and RNA are readily detected in most organs and cell types but remarkably absent in skeletal muscle. Here we report that mouse C2C12 myoblasts that are readily infected by LCMV, become highly refractory to LCMV infection upon their differentiation into myotubes. Myotube's resistance to LCMV was not due to an intracellular restriction of virus replication but rather an impaired cell entry mediated by the LCMV surface glycoprotein. Our findings provide an explanation for the observation that in LCMV carrier mice myotubes, which are constantly exposed to blood-containing virus, remain free of viral antigen and RNA despite myotubes express high levels of the LCMV receptor alpha dystroglycan and do not pose an intracellular blockade to LCMV multiplication.

  17. Mice deficient in STAT1 but not STAT2 or IRF9 develop a lethal CD4+ T-cell-mediated disease following infection with lymphocytic choriomeningitis virus

    NARCIS (Netherlands)

    Hofer, M.J.; Li, W.; Manders, P.; Terry, R.; Lim, S.L.; King, N.J.; Campbell, I.L.

    2012-01-01

    Interferon (IFN) signaling is crucial for antiviral immunity. While type I IFN signaling is mediated by STAT1, STAT2, and IRF9, type II IFN signaling requires only STAT1. Here, we studied the roles of these signaling factors in the host response to systemic infection with lymphocytic choriomeningiti

  18. CD40 ligand is pivotal to efficient control of virus replication in mice infected with lymphocytic choriomeningitis virus

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Nansen, A; Christensen, Jan Pravsgaard;

    1998-01-01

    internal organs approximately 6 mo after virus inoculation. Since the impairment of immune function seems to be more pronounced in CD40L-deficient mice than in mice lacking either CD4+ cells or B cells, these results indicate that CD40L is pivotal to sustain efficient antiviral immune surveillance...

  19. Persistent virus infection despite chronic cytotoxic T-lymphocyte activation in gamma interferon-deficient mice infected with lymphocytic choriomeningitis virus

    DEFF Research Database (Denmark)

    Bartholdy, C; Christensen, Jan Pravsgaard; Wodarz, D;

    2000-01-01

    ). While wild-type mice rapidly cleared the infection, IFN-gamma -/- mice became chronically infected. Virus persistence in the latter mice did not reflect failure to generate cytotoxic T-lymphocyte (CTL) effectors, as an unimpaired primary CTL response was observed. Furthermore, while ex vivo CTL activity...

  20. Lymphocytic choriomeningitis virus infection is associated with long-standing perturbation of LFA-1 expression on CD8+ T cells

    DEFF Research Database (Denmark)

    Andersson, E C; Christensen, Jan Pravsgaard; Scheynius, A;

    1995-01-01

    belonged to the CD8+LFA-1hi subset and, correspondingly, the ligand ICAM-1 was found to be up-regulated on endothelial cells in the inflamed meninges. Preincubation of LCMV-primed donor splenocytes with anti-LFA-1 markedly inhibited the transfer of virus-specific delayed-type hypersensitivity to naive...... recipients. Together, these findings indicate that up-regulation of LFA-1 expression is a critical factor involved in directing activated CD8+ T cells to sites of viral infection....

  1. CXCL10 is the key ligand for CXCR3 on CD8+ effector T cells involved in immune surveillance of the lymphocytic choriomeningitis virus-infected central nervous system

    DEFF Research Database (Denmark)

    Christensen, Jeanette Erbo; de Lemos, Carina; Moos, Torben;

    2006-01-01

    IFN-gamma-inducible protein 10/CXCL10 is a chemokine associated with type 1 T cell responses, regulating the migration of activated T cells through binding to the CXCR3 receptor. Expression of both CXCL10 and CXCR3 are observed during immunopathological diseases of the CNS, and this receptor....../ligand pair is thought to play a central role in regulating T cell-mediated inflammation in this organ site. In this report, we investigated the role of CXCL10 in regulating CD8(+) T cell-mediated inflammation in the virus-infected brain. This was done through analysis of CXCL10-deficient mice infected...... intracerebrally with lymphocytic choriomeningitis virus, which in normal immunocompetent mice induces a fatal CD8(+) T cell-mediated meningoencephalitis. We found that a normal antiviral CD8(+) T cell response was generated in CXCL10-deficient mice, and that lack of CXCL10 had no influence on the accumulation...

  2. Attenuation of the cytotoxic T lymphocyte response to lymphocytic choriomeningitis virus in mice subjected to chronic social stress

    OpenAIRE

    Sommershof, Annette; Basler, Michael; Riether, Carsten; Engler, Harald; Gröttrup, Marcus

    2011-01-01

    Chronic stress is suspected to increase the susceptibility to infections but experimental evidence from physiological stress models is scarce. We examined the effects of chronic social stress on virus-specific CTL responses in mice after infection with lymphocytic choriomeningitis virus (LCMV). Mice subjected to social stress on six consecutive days prior to infection showed a significant reduction of IFN-γ producing TCD8+ splenocytes and markedly lowered plasma concentrations of IFN-γ. In co...

  3. Role of an Intact Splenic Microarchitecture in Early Lymphocytic Choriomeningitis Virus Production

    OpenAIRE

    Müller, Stefan; Hunziker, Lukas; Enzler, Susanne; Bühler-Jungo, Myriam; Di Santo, James P.; Zinkernagel, Rolf M.; Mueller, C.

    2002-01-01

    An acute infection with lymphocytic choriomeningitis virus (LCMV) is efficiently controlled by the cytotoxic-T-cell (CTL) response of the host, and LCMV titers in the spleen and peripheral solid organs usually fall sharply after day 4 to 6 postinfection. Surprisingly, infection of immunodeficient recombination-activating gene 2-deficient (RAG2−/−) mice with 5 × 102 PFU of LCMV-WE causes about 80-fold-lower LCMV titers in the spleen on day 4 postinfection compared with C57BL/6 control mice. Th...

  4. Concanavalin A-induced activation of lymphocytic choriomeningitis virus memory lymphocytes into specifically cytotoxic T cells

    DEFF Research Database (Denmark)

    Marker, O; Thomsen, Allan Randrup; Andersen, G T

    1977-01-01

    When spleen cells, which have been primed to Lymphocytic Choriomeningitis (LCM) virus during a primary infection several months previously, are stimulated in vitro with Con A. highly specific secondary cytotoxic effector cells are generated. The degree of cytotoxicity revealed by such Con A......-stimulated cells is higher than that of non-incubated spleen cells harvested nine days following the primary infection, and the effect is totally inhibited by anti-theta serum plus complement treatment of the effector cells immediately before the cytotoxic test....

  5. MHC and non-MHC genes regulate elimination of lymphocytic choriomeningitis virus and antiviral cytotoxic T lymphocyte and delayed-type hypersensitivity mediating T lymphocyte activity in parallel

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Marker, O

    1989-01-01

    The course of systemic infection with lymphocytic choriomeningitis virus was studied in mouse strains differing in the MHC or non-MHC background. Virus clearance rates differed significantly between H-2 identical strains as well as between congenic strains differing in the H-2L subregion, indicat......The course of systemic infection with lymphocytic choriomeningitis virus was studied in mouse strains differing in the MHC or non-MHC background. Virus clearance rates differed significantly between H-2 identical strains as well as between congenic strains differing in the H-2L subregion...

  6. The Lymphocytic Choriomeningitis Virus Matrix Protein PPXY Late Domain Drives the Production of Defective Interfering Particles.

    Directory of Open Access Journals (Sweden)

    Christopher M Ziegler

    2016-03-01

    Full Text Available Arenaviruses cause severe diseases in humans but establish asymptomatic, lifelong infections in rodent reservoirs. Persistently-infected rodents harbor high levels of defective interfering (DI particles, which are thought to be important for establishing persistence and mitigating virus-induced cytopathic effect. Little is known about what drives the production of DI particles. We show that neither the PPXY late domain encoded within the lymphocytic choriomeningitis virus (LCMV matrix protein nor a functional endosomal sorting complex transport (ESCRT pathway is absolutely required for the generation of standard infectious virus particles. In contrast, DI particle release critically requires the PPXY late domain and is ESCRT-dependent. Additionally, the terminal tyrosine in the PPXY motif is reversibly phosphorylated and our findings indicate that this posttranslational modification may regulate DI particle formation. Thus we have uncovered a new role for the PPXY late domain and a possible mechanism for its regulation.

  7. Lymphocytic choriomeningitis virus in employees and mice at multipremises feeder-rodent operation, United States, 2012.

    Science.gov (United States)

    Knust, Barbara; Ströher, Ute; Edison, Laura; Albariño, César G; Lovejoy, Jodi; Armeanu, Emilian; House, Jennifer; Cory, Denise; Horton, Clayton; Fowler, Kathy L; Austin, Jessica; Poe, John; Humbaugh, Kraig E; Guerrero, Lisa; Campbell, Shelley; Gibbons, Aridth; Reed, Zachary; Cannon, Deborah; Manning, Craig; Petersen, Brett; Metcalf, Douglas; Marsh, Bret; Nichol, Stuart T; Rollin, Pierre E

    2014-02-01

    We investigated the extent of lymphocytic choriomeningitis virus (LCMV) infection in employees and rodents at 3 commercial breeding facilities. Of 97 employees tested, 31 (32%) had IgM and/or IgG to LCMV, and aseptic meningitis was diagnosed in 4 employees. Of 1,820 rodents tested in 1 facility, 382 (21%) mice (Mus musculus) had detectable IgG, and 13 (0.7%) were positive by reverse transcription PCR; LCMV was isolated from 8. Rats (Rattus norvegicus) were not found to be infected. S-segment RNA sequence was similar to strains previously isolated in North America. Contact by wild mice with colony mice was the likely source for LCMV, and shipments of infected mice among facilities spread the infection. The breeding colonies were depopulated to prevent further human infections. Future outbreaks can be prevented with monitoring and management, and employees should be made aware of LCMV risks and prevention. PMID:24447605

  8. Lymphocytic choriomeningitis virus-induced immunosuppression: evidence for viral interference with T-cell maturation

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Bro-Jørgensen, K; Jensen, Birgitte Løkke

    1982-01-01

    Acute lymphocytic choriomeningitis virus (LCMV) infection is associated with general immunosuppression which develops during the second week of the infection and persists for several weeks. In the present study, the ability of LCMV-infected mice to mount a cytotoxic T-lymphocyte response was...... investigated in a transplantation assay, using LCMV-immunized mice as recipients. By this means it was possible to evaluate the T-cell responsiveness of the acutely infected mice separately. Our results revealed a marked depression of the T-cell function temporally related to immunosuppression in the intact...... that a numerical deficiency of immunocompetent T-cells due to viral interference with T-cell maturation plays an important role in LCMV-induced immunosuppression....

  9. T-cell effector function and unresponsiveness in the murine lymphocytic choriomeningitis virus infection. II. Delayed-type hypersensitivity unresponsiveness reflects a defective differentiation from TD precursor to effector cell

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Marker, O

    1986-01-01

    An increase in the virus dose from 10(2) LD50 (low dose) to 10(4) LD50 (high dose) of lymphocytic choriomeningitis virus (LCMV) results in markedly delayed virus clearance, in spite of a potent cytotoxic T-cell (TC) response. However, virus-specific delayed-type hypersensitivity (DTH) reactivity...... is markedly depressed in high-dose mice, suggesting an association between DTH and virus clearance. When virus-primed memory cells are transferred, DTH reactivity as well as virus-clearing capacity is restored in high-dose mice, indicating that the virus is not present in a changed or concealed form. The role...... of T-cells mediating DTH (TD cells) in virus clearance was also studied by adoptive transfer to naive recipients. Here the high-dose primed cells did mediate virus clearance, although no DTH reaction was detectable 24-72 h after transfer. However, when footpad swelling was measured 96 h or more after...

  10. Differential Impact of Interferon Regulatory Factor 7 in Initiation of the Type I Interferon Response in the Lymphocytic Choriomeningitis Virus-Infected Central Nervous System versus the Periphery

    DEFF Research Database (Denmark)

    Christensen, Jeanette Erbo; Fenger, Christina; Issazadeh-Navikas, Shohreh;

    2012-01-01

    Interferon (IFN) regulatory factors (IRFs) are a family of transcription factors involved in regulating type I IFN genes and other genes participating in the early antiviral host response. To better understand the mechanisms involved in virus-induced central nervous system (CNS) inflammation, we...

  11. T-cell effector function and unresponsiveness in the murine lymphocytic choriomeningitis virus infection. I. On the mechanism of a selective suppression of the virus-specific delayed-type hypersensitivity response

    DEFF Research Database (Denmark)

    Marker, O; Thomsen, Allan Randrup

    1986-01-01

    pretreated with neutralizing anti-LCMV serum, indicating a suppressive effect of virus transferred with the infected cells. When tolerance induction was attempted with virus alone, a potentially fatal immune reaction could be altered to unresponsiveness (i.e. survival) as late as 4 days after an otherwise......-cell response remains essentially unchanged. When low-dose spleen effectors were transferred intravenously into intracerebrally infected high-dose mice, fatal LCM disease occurred, which means that infected central nervous system target structures in these animals are sensitive to virus-specific T cells. When...

  12. Platelets prevent IFN-alpha/beta-induced lethal hemorrhage promoting CTL-dependent clearance of lymphocytic choriomeningitis virus.

    Science.gov (United States)

    Iannacone, Matteo; Sitia, Giovanni; Isogawa, Masanori; Whitmire, Jason K; Marchese, Patrizia; Chisari, Francis V; Ruggeri, Zaverio M; Guidotti, Luca G

    2008-01-15

    We found that mice infected with different isolates of lymphocytic choriomeningitis virus (LCMV) develop a mild hemorrhagic anemia, which becomes severe and eventually lethal in animals depleted of platelets or lacking integrin beta3. Lethal hemorrhagic anemia is mediated by virus-induced IFN-alpha/beta that causes platelet dysfunction, mucocutaneous blood loss and suppression of erythropoiesis. In addition to the life-threatening hemorrhagic anemia, platelet-depleted mice fail to mount an efficient cytotoxic T lymphocyte (CTL) response and cannot clear LCMV. Transfusion of functional platelets into these animals reduces hemorrhage, prevents death and restores CTL-induced viral clearance in a manner partially dependent on CD40 ligand (CD40L). These results indicate that, upon activation, platelets expressing integrin beta3 and CD40L are required for protecting the host against the induction of an IFN-alpha/beta-dependent lethal hemorrhagic diathesis and for clearing LCMV infection through CTLs.

  13. Fulminant lymphocytic choriomeningitis virus-induced inflammation of the CNS involves a cytokine-chemokine-cytokine-chemokine cascade

    DEFF Research Database (Denmark)

    Christensen, Jeanette Erbo; Simonsen, Stine; Fenger, Christina;

    2009-01-01

    Intracerebral inoculation of immunocompetent mice with lymphocytic choriomeningitis virus (LCMV) normally results in fatal CD8+ T cell mediated meningoencephalitis. However, in CXCL10-deficient mice, the virus-induced CD8+ T cell accumulation in the neural parenchyma is impaired, and only 30......-50% of the mice succumb to the infection. Similar results are obtained in mice deficient in the matching chemokine receptor, CXCR3. Together, these findings point to a key role for CXCL10 in regulating the severity of the LCMV-induced inflammatory process. For this reason, we now address the mechanisms regulating...... the expression of CXCL10 in the CNS of LCMV-infected mice. Using mice deficient in type I IFN receptor, type II IFN receptor, or type II IFN, as well as bone marrow chimeras expressing CXCL10 only in resident cells or only in bone marrow-derived cells, we analyzed the up-stream regulation as well as the cellular...

  14. Development and application of ELISA for the detection of IgG antibodies to lymphocytic choriomeningitis virus.

    Science.gov (United States)

    Lapošová, K; Lukáčiková, Ľ; Ovečková, I; Pastoreková, S; Rosocha, J; Kuba, D; Beňa, Ľ; Tomášková, J

    2016-06-01

    Lymphocytic choriomeningitis virus (LCMV) is a neglected human pathogen, which can cause severe illnesses in humans. The most vulnerable are the human foetus and immunosuppressed individuals. Since there is no commercially available enzyme-linked immunosorbent assay (ELISA) for the diagnosis of anti-LCMV antibodies in human sera, we developed a sandwich ELISA method detecting anti-nucleoprotein IgG antibodies, using a specific monoclonal anti-nucleoprotein antibody and cells persistently infected with LCMV strain MX as antigen. In the present study we show standardization of this ELISA protocol, determination of its clinical specificity and sensitivity and its application on 30 clinical samples from multiorgan donors. Comparison of these results to the indirect immunofluorescence antibody test (IFA) demonstrates that ELISA is more sensitive. The developed ELISA assay provides a fast, simple and efficient tool for the clinical detection of anti-nucleoprotein antibodies in human sera. PMID:27265463

  15. Fulminant lymphocytic choriomeningitis virus-induced inflammation of the CNS involves a cytokine-chemokine-cytokine-chemokine cascade

    DEFF Research Database (Denmark)

    Christensen, Jeanette E; Simonsen, Stine; Fenger, Christina;

    2009-01-01

    Intracerebral inoculation of immunocompetent mice with lymphocytic choriomeningitis virus (LCMV) normally results in fatal CD8+ T cell mediated meningoencephalitis. However, in CXCL10-deficient mice, the virus-induced CD8+ T cell accumulation in the neural parenchyma is impaired, and only 30...... of the CNS, and astrocytes are the dominant expressors in the neural parenchyma, not microglial cells or recruited bone marrow-derived cell types. These results are consistent with a model suggesting a bidirectional interplay between resident cells of the CNS and the recruited virus-specific T cells...

  16. Congenitally acquired persistent lymphocytic choriomeningitis viral infection reduces neuronal progenitor pools in the adult hippocampus and subventricular zone.

    Directory of Open Access Journals (Sweden)

    Tony Sun

    Full Text Available Lymphocytic choriomeningitis virus (LCMV can be transmitted through congenital infection, leading to persistent infection of numerous organ systems including the central nervous system (CNS. Adult mice persistently infected with LCMV (LCMV-cgPi mice exhibit learning deficits, such as poor performance in spatial discrimination tests. Given that deficits in spatial learning have been linked to defects in adult neurogenesis, we investigated the impact of congenital LCMV infection on generation of neuroblasts from neural progenitor cells within neurogenic zones of adult mice. In LCMV-cgPi mice, QPCR and immunohistochemistry detected presence of LCMV glycoprotein-coding RNA and nucleoprotein in the hippocampal dentate gyrus and subventricular zone (SVZ, sites of neurogenesis that harbor populations of neuroblasts. Numbers of neuroblasts were reduced in LCMV-cgPi mice, as determined by IHC quantification, and analysis of BrdU incorporation by flow cytometry revealed lower numbers of BrdU-labeled neuroblasts. Additionally, TUNEL assays performed in situ showed increased numbers of apoptotic cells in the two neurogenic regions. Next, neurosphere cultures were infected in vitro with LCMV and differentiated to create a population of cells that consisted of both transit amplifying cells and neuroblasts. Immunocytochemical and TUNEL assays revealed increased numbers of TUNEL-positive cells that express nestin, suggesting that the drop in numbers of neuroblasts was due to a combination of impaired proliferation and apoptosis of progenitor cells. LCMV-cgPi mice exhibited transcriptional up-regulation several cytokines and chemokines, including gamma-interferon inducible chemokines CXCL9 and CXCL10. Chronic up-regulation of these chemokines can facilitate a pro-inflammatory niche that may contribute to defects in neurogenesis.

  17. The complementary roles of cellular and humoral immunity in resistance to re-infection with LCM virus

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Marker, O

    1988-01-01

    The mechanisms underlying resistance to re-infection with lymphocytic choriomeningitis virus (LCMV) were investigated. Rechallenge with moderate doses of virus (10(3) LD50) did not lead to detectable re-infection nor to re-induction of virus-specific cytotoxicity. When higher doses of virus were ...

  18. Pathogenesis of Lassa Fever Virus Infection: I. Susceptibility of Mice to Recombinant Lassa Gp/LCMV Chimeric Virus

    OpenAIRE

    Lee, Andrew M.; Cruite, Justin; Welch, Megan J.; Sullivan, Brian; Oldstone, Michael B. A.

    2013-01-01

    Lassa virus (LASV) is a BSL-4 restricted agent. To allow study of infection by LASV under BSL-2 conditions, we generated a recombinant virus in which the LASV glycoprotein (Gp) was placed on the backbone of lymphocytic choriomeningitis virus (LCMV) Cl13 nucleoprotein, Z and polymerase genes (rLCMV Cl13/LASV Gp). The recombinant virus displayed high tropism for dendritic cells following in vitro or in vivo infection. Inoculation of immunocompetent adults resulted in an acute infection, generat...

  19. Toso regulates differentiation and activation of inflammatory dendritic cells during persistence-prone virus infection

    OpenAIRE

    Lang, P A; Meryk, A; Pandyra, A A; Brenner, D; A. Brüstle; Xu, H. C.; Merches, K; Lang, F; Khairnar, V; Sharma, P; Funkner, P; Recher, M.; Shaabani, N.; Duncan, G S; Duhan, V

    2014-01-01

    During virus infection and autoimmune disease, inflammatory dendritic cells (iDCs) differentiate from blood monocytes and infiltrate infected tissue. Following acute infection with hepatotropic viruses, iDCs are essential for re-stimulating virus-specific CD8+ T cells and therefore contribute to virus control. Here we used the lymphocytic choriomeningitis virus (LCMV) model system to identify novel signals, which influence the recruitment and activation of iDCs in the liver. We observed that ...

  20. Early Blood Profiles of Virus Infection in a Monkey Model for Lassa Fever▿ †

    OpenAIRE

    Djavani, Mahmoud M.; Crasta, Oswald R.; Zapata, Juan Carlos; Fei, Zhangjun; Folkerts, Otto; Sobral, Bruno; Swindells, Mark; Bryant, Joseph; Davis, Harry; Pauza, C. David; Lukashevich, Igor S.; Hammamieh, Rasha; Jett, Marti; Salvato, Maria S.

    2007-01-01

    Acute arenavirus disease in primates, like Lassa hemorrhagic fever in humans, begins with flu-like symptoms and leads to death approximately 2 weeks after infection. Our goal was to identify molecular changes in blood that are related to disease progression. Rhesus macaques (Macaca mulatta) infected intravenously with a lethal dose of lymphocytic choriomeningitis virus (LCMV) provide a model for Lassa virus infection of humans. Blood samples taken before and during the course of infection wer...

  1. Pet Rodents and Fatal Lymphocytic Choriomeningitis in Transplant Patients

    Centers for Disease Control (CDC) Podcasts

    2007-05-16

    Three organ transplant recipients died from infection with lymphocytic choriomeningitis virus (LCMV), which was traced back to a hamster owned by the daughter of the organ donor. Dr. Brian Amman, a mammalogist with the Special Pathogens Branch at CDC, discusses the dangers LCMV may pose to people with immune disorders, as well as to pregnant women.  Created: 5/16/2007 by CDC, Office of the Director.   Date Released: 5/16/2007.

  2. T-cell-mediated immunity to lymphocytic choriomeningitis virus in beta2-integrin (CD18)- and ICAM-1 (CD54)-deficient mice

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Marker, O; Thomsen, Allan Randrup

    1996-01-01

    The T-cell response to lymphocytic choriomeningitis virus was studied in mice with deficient expression of beta2-integrins or ICAM-1. In such mice, the generation of virus-specific cytotoxic T lymphocytes was only slightly impaired and bystander activation was as extensive as that observed in wild...... the inflammatory reaction, indicating that under conditions of more limited immune activation both molecules do play a role in formation of the inflammatory exudate. Finally, virus control was found to be somewhat impaired in both mutant strains. In conclusion, our results indicate that although LFA-1-ICAM-1...

  3. Pathogenesis of Lassa fever virus infection: I. Susceptibility of mice to recombinant Lassa Gp/LCMV chimeric virus.

    Science.gov (United States)

    Lee, Andrew M; Cruite, Justin; Welch, Megan J; Sullivan, Brian; Oldstone, Michael B A

    2013-08-01

    Lassa virus (LASV) is a BSL-4 restricted agent. To allow study of infection by LASV under BSL-2 conditions, we generated a recombinant virus in which the LASV glycoprotein (Gp) was placed on the backbone of lymphocytic choriomeningitis virus (LCMV) Cl13 nucleoprotein, Z and polymerase genes (rLCMV Cl13/LASV Gp). The recombinant virus displayed high tropism for dendritic cells following in vitro or in vivo infection. Inoculation of immunocompetent adults resulted in an acute infection, generation of virus-specific CD8(+) T cells and clearance of the infection. Inoculation of newborn mice with rLCMV Cl13/LASV Gp resulted in a life-long persistent infection. Interestingly, adoptive transfer of rLCMV Cl13/LASV Gp immune memory cells into such persistently infected mice failed to purge virus but, in contrast, cleared virus from mice persistently infected with wt LCMV Cl13. PMID:23684417

  4. Pathogenesis of Lassa Fever Virus Infection: I. Susceptibility of Mice to Recombinant Lassa Gp/LCMV Chimeric Virus

    Science.gov (United States)

    Lee, Andrew M.; Cruite, Justin; Welch, Megan J.; Sullivan, Brian; Oldstone, Michael B.A.

    2013-01-01

    Lassa virus (LASV) is a BSL-4 restricted agent. To allow study of infection by LASV under BSL-2 conditions, we generated a recombinant virus in which the LASV glycoprotein (Gp) was placed on the backbone of lymphocytic choriomeningitis virus (LCMV) Cl13 nucleoprotein, Z and polymerase genes (rLCMV Cl13/LASV Gp). The recombinant virus displayed high tropism for dendritic cells following in vitro or in vivo infection. Inoculation of immunocompetent adults resulted in an acute infection, generation of virus-specific CD8+ T cells and clearance of the infection. Inoculation of newborn mice with rLCMV Cl13/LASV Gp resulted in a life-long persistent infection. Interestingly, adoptive transfer of rLCMV Cl13/LASV Gp immune memory cells into such persistently infected mice failed to purge virus but, in contrast, cleared virus from mice persistently infected with wt LCMV Cl13. PMID:23684417

  5. Virus Infection

    Directory of Open Access Journals (Sweden)

    Hiroshi Abe

    2013-01-01

    Full Text Available Of 168 patients with chronic hepatitis B virus (HBV infection-related liver disease, 20 patients who had received 100 mg of lamivudine plus 10 mg/day of adefovir dipivoxil (ADV (ADV group and 124 patients who had received 0.5 mg/day of entecavir or 100 mg/day of lamivudine (non-ADV group for >1 year were enrolled. For comparative analyses, 19 well-matched pairs were obtained from the groups by propensity scores. At the time of enrollment, serum creatinine and phosphate concentrations were similar between the ADV and non-ADV groups; however, urinary phosphate ( and serum bone-specific alkaline phosphatase (BAP ( concentrations were significantly higher in the ADV group than in the non-ADV group. Serum BAP was significantly higher at the time of enrollment than before ADV administration in the ADV group (, although there was no significant change in serum BAP concentration in the non-ADV group. There was a significant positive correlation between the period of ADV therapy and ΔBAP (, . Serum BAP concentration increased before increase in serum creatinine concentration and was useful for early detection of adverse events and for developing adequate measures for continuing ADV for chronic HBV infection-related liver disease.

  6. Lysis of uninfected and virus-infected cells in vivo: a rejection mechanism in addition to that mediated by natural killer cells.

    OpenAIRE

    Biron, C. A.; Habu, S.; Okumura, K.; Welsh, R. M.

    1984-01-01

    To examine the lysis of virus-infected cells in vivo, uninfected and lymphocytic choriomeningitis virus (LCMV)-infected L-929 cells were labeled in vitro with [125I]-iododeoxyuridine and implanted intravenously into mice. Natural cytotoxicity against both uninfected and virus-infected cells was demonstrated in normal uninfected mice, but LCMV-infected cells were cleared from the lungs and whole bodies more rapidly than uninfected cells. Treatment of L-929 cells with defective interfering LCMV...

  7. 9 CFR 113.42 - Detection of lymphocytic choriomeningitis contamination.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Detection of lymphocytic choriomeningitis contamination. 113.42 Section 113.42 Animals and Animal Products ANIMAL AND PLANT HEALTH... contamination. The test for detection of lymphocytic choriomeningitis (LCM) virus provided in this section...

  8. Alpha 4 integrin directs virus-activated CD8+ T cells to sites of infection

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Andersson, E C; Scheynius, A;

    1995-01-01

    This article examines the role of VLA-4 in directing lymphocytes to sites of viral infection using the murine lymphocytic choriomeningitis virus infection (LCMV) as the model system. This virus by itself induces little or no inflammation, but in most mouse/virus strain combinations a potent T cell...... response is induced, which is associated with marked CD8+ cell-mediated inflammation. Two expressions of LCMV-induced inflammation were studied: meningitis induced by intracerebral infection and adoptive transfer of virus-specific delayed-type hypersensitivity. Our previous studies have shown that LCMV...

  9. Viruses Infecting Reptiles

    OpenAIRE

    Marschang, Rachel E.

    2011-01-01

    A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The ...

  10. Viruses Infecting Reptiles

    Directory of Open Access Journals (Sweden)

    Rachel E. Marschang

    2011-11-01

    Full Text Available A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.

  11. Prenatal brain MRI of fetuses with Zika virus infection

    Energy Technology Data Exchange (ETDEWEB)

    Guillemette-Artur, Prisca [Centre Hospitalier de Polynesie Francaise, Service de Radiologie, Pirae, Tahiti (Country Unknown); Besnard, Marianne [Centre Hospitalier de Polynesie Francaise, Service de Reanimation Neo-natale, Pirae, Tahiti (Country Unknown); Eyrolle-Guignot, Dominique [Centre Hospitalier de Polynesie Francaise, Service d' Obstetrique, Pirae, Tahiti (Country Unknown); Jouannic, Jean-Marie [Universite Pierre et Marie Curie, Service de Medecine Foetale, Hopital d' Enfants Armand-Trousseau, Paris (France); Garel, Catherine [Hopital d' Enfants Armand-Trousseau, Department of Radiology, Paris (France)

    2016-06-15

    An outbreak of Zika virus was observed in French Polynesia in 2013-2014. Maternal Zika virus infection has been associated with fetal microcephaly and severe cerebral damage. To analyze the MRI cerebral findings in fetuses with intrauterine Zika virus infection. We retrospectively analyzed prospectively collected data. Inclusion criteria comprised cases with (1) estimated conception date between June 2013 and May 2014, (2) available US and MRI scans revealing severe fetal brain lesions and (3) positive polymerase chain reaction for Zika virus in the amniotic fluid. We recorded pregnancy history of Zika virus infection and analyzed US and MRI scans. Three out of 12 cases of severe cerebral lesions fulfilled all inclusion criteria. History of maternal Zika virus infection had been documented in two cases. Calcifications and ventriculomegaly were present at US in all cases. MRI showed micrencephaly (n = 3), low cerebellar biometry (n = 2), occipital subependymal pseudocysts (n = 2), polymicrogyria with laminar necrosis and opercular dysplasia (n = 3), absent (n = 1) or hypoplastic (n = 1) corpus callosum and hypoplastic brainstem (n = 1). Severe cerebral damage was observed in our series, with indirect findings suggesting that the germinal matrix is the principal target for Zika virus. The lesions are very similar to severe forms of congenital cytomegalovirus and lymphocytic choriomeningitis virus infections. (orig.)

  12. Interleukin-21 mRNA expression during virus infections

    DEFF Research Database (Denmark)

    Holm, Christian; Nyvold, Charlotte Guldborg; Paludan, Søren Riis;

    2006-01-01

    and activational effects of IL-21 on different leukocytes come into play in vivo in an immune response has so far not been fully investigated. We show here for the first time in vivo, that IL-21 mRNA is produced in the spleen when mice are challenged with herpes simplex virus type 2 (HSV-2) or lymphocytic...... choriomeningitis virus (LCMV). We show in HSV-2 challenged mice that this production takes place in CD4+ T cell fractions and is absent in CD4+ T cell-depleted fractions. We also show that the peak of IL-21 mRNA production in both the HSV-2 and LCMV-challenged mice coincides with the onset of the adaptive immune...... response. Thus, our data suggest a role for IL-21 in the early stages of adaptive immune response against virus infections....

  13. Lambda Interferon (IFN-gamma), a Type III IFN, is induced by viruses and IFNs and displays potent antiviral activity against select virus infections in vivo

    DEFF Research Database (Denmark)

    Ank, Nina; West, Hans; Bartholdy, C.;

    2006-01-01

    -alpha/beta)-induced directly by stimulation with IFN-alpha or -lambda, thus identifying type III IFNs as IFN-stimulated genes. In vitro assays revealed that IFN-lambdas have appreciable antiviral activity against encephalomyocarditis virus (EMCV) but limited activity against herpes simplex virus type 2 (HSV-2), whereas IFN-alpha...... potently restricted both viruses. Using three murine models for generalized virus infections, we found that while recombinant IFN-alpha reduced the viral load after infection with EMCV, lymphocytic choriomeningitis virus (LCMV), and HSV-2, treatment with recombinant IFN-lambda in vivo did not affect viral...... load after infection with EMCV or LCMV but did reduce the hepatic viral titer of HSV-2. In a model for a localized HSV-2 infection, we further found that IFN-lambda completely blocked virus replication in the vaginal mucosa and totally prevented development of disease, in contrast to IFN-alpha, which...

  14. Lambda interferon (IFN-lambda), a type III IFN, is induced by viruses and IFNs and displays potent antiviral activity against select virus infections in vivo

    DEFF Research Database (Denmark)

    Ank, Nina; West, Hans; Bartholdy, Christina;

    2006-01-01

    -alpha/beta)-induced directly by stimulation with IFN-alpha or -lambda, thus identifying type III IFNs as IFN-stimulated genes. In vitro assays revealed that IFN-lambdas have appreciable antiviral activity against encephalomyocarditis virus (EMCV) but limited activity against herpes simplex virus type 2 (HSV-2), whereas IFN-alpha...... potently restricted both viruses. Using three murine models for generalized virus infections, we found that while recombinant IFN-alpha reduced the viral load after infection with EMCV, lymphocytic choriomeningitis virus (LCMV), and HSV-2, treatment with recombinant IFN-lambda in vivo did not affect viral...... load after infection with EMCV or LCMV but did reduce the hepatic viral titer of HSV-2. In a model for a localized HSV-2 infection, we further found that IFN-lambda completely blocked virus replication in the vaginal mucosa and totally prevented development of disease, in contrast to IFN-alpha, which...

  15. [ZIKA--VIRUS INFECTION].

    Science.gov (United States)

    Velev, V

    2016-01-01

    This review summarizes the knowledge of the scientific community for Zika-virus infection. It became popular because of severe congenital damage causes of CNS in newborns whose mothers are infected during pregnancy, as well as the risk of pandemic distribution. Discusses the peculiarities of the biology and ecology of vectors--blood-sucking mosquitoes Aedes; stages in the spread of infection and practical problems which caused during pregnancy. Attention is paid to the recommendations that allow leading national and international medical organizations to deal with the threat Zika-virus infection.

  16. [ZIKA--VIRUS INFECTION].

    Science.gov (United States)

    Velev, V

    2016-01-01

    This review summarizes the knowledge of the scientific community for Zika-virus infection. It became popular because of severe congenital damage causes of CNS in newborns whose mothers are infected during pregnancy, as well as the risk of pandemic distribution. Discusses the peculiarities of the biology and ecology of vectors--blood-sucking mosquitoes Aedes; stages in the spread of infection and practical problems which caused during pregnancy. Attention is paid to the recommendations that allow leading national and international medical organizations to deal with the threat Zika-virus infection. PMID:27509655

  17. Early Blood Profiles of Virus Infection in a Monkey Model for Lassa Fever▿ †

    Science.gov (United States)

    Djavani, Mahmoud M.; Crasta, Oswald R.; Zapata, Juan Carlos; Fei, Zhangjun; Folkerts, Otto; Sobral, Bruno; Swindells, Mark; Bryant, Joseph; Davis, Harry; Pauza, C. David; Lukashevich, Igor S.; Hammamieh, Rasha; Jett, Marti; Salvato, Maria S.

    2007-01-01

    Acute arenavirus disease in primates, like Lassa hemorrhagic fever in humans, begins with flu-like symptoms and leads to death approximately 2 weeks after infection. Our goal was to identify molecular changes in blood that are related to disease progression. Rhesus macaques (Macaca mulatta) infected intravenously with a lethal dose of lymphocytic choriomeningitis virus (LCMV) provide a model for Lassa virus infection of humans. Blood samples taken before and during the course of infection were used to monitor gene expression changes that paralleled disease onset. Changes in blood showed major disruptions in eicosanoid, immune response, and hormone response pathways. Approximately 12% of host genes alter their expression after LCMV infection, and a subset of these genes can discriminate between virulent and nonvirulent LCMV infection. Major transcription changes have been given preliminary confirmation by quantitative PCR and protein studies and will be valuable candidates for future validation as biomarkers for arenavirus disease. PMID:17522210

  18. Early blood profiles of virus infection in a monkey model for Lassa fever.

    Science.gov (United States)

    Djavani, Mahmoud M; Crasta, Oswald R; Zapata, Juan Carlos; Fei, Zhangjun; Folkerts, Otto; Sobral, Bruno; Swindells, Mark; Bryant, Joseph; Davis, Harry; Pauza, C David; Lukashevich, Igor S; Hammamieh, Rasha; Jett, Marti; Salvato, Maria S

    2007-08-01

    Acute arenavirus disease in primates, like Lassa hemorrhagic fever in humans, begins with flu-like symptoms and leads to death approximately 2 weeks after infection. Our goal was to identify molecular changes in blood that are related to disease progression. Rhesus macaques (Macaca mulatta) infected intravenously with a lethal dose of lymphocytic choriomeningitis virus (LCMV) provide a model for Lassa virus infection of humans. Blood samples taken before and during the course of infection were used to monitor gene expression changes that paralleled disease onset. Changes in blood showed major disruptions in eicosanoid, immune response, and hormone response pathways. Approximately 12% of host genes alter their expression after LCMV infection, and a subset of these genes can discriminate between virulent and non-virulent LCMV infection. Major transcription changes have been given preliminary confirmation by quantitative PCR and protein studies and will be valuable candidates for future validation as biomarkers for arenavirus disease. PMID:17522210

  19. Feline immunodeficiency virus infection.

    Science.gov (United States)

    Pedersen, N C; Yamamoto, J K; Ishida, T; Hansen, H

    1989-05-01

    Feline immunodeficiency virus (FIV) (formerly feline T-lymphotropic lentivirus or FTLV) was first isolated from a group of cats in Petaluma, California in 1986. The virus is a typical lentivirus in gross and structural morphology. It replicates preferentially but not exclusively in feline T-lymphoblastoid cells, where it causes a characteristic cytopathic effect. The major structural proteins are 10, 17 (small gag), 28 (major core), 31 (endonuclease?), 41 (transmembrane?), 52 (core precursor polyprotein), 54/62 (reverse transcriptase?), and 110/130 (major envelope) kilodaltons in size. The various proteins are antigenically distinguishable from those of other lentiviruses, although serum from EIAV-infected horses will cross-react with some FIV antigens. Kittens experimentally infected with FIV manifest a transient (several days to 2 weeks) fever and neutropenia beginning 4 to 8 weeks after inoculation. This is associated with a generalized lymphadenopathy that persists for up to 9 months. Most cats recover from this initial phase of the disease and become lifelong carriers of the virus. Complete recovery does not occur to any extent in nature or in the laboratory setting. One experimentally infected cat died from a myeloproliferative disorder several months after infection. The terminal AIDS-like phase of the illness has been seen mainly in naturally infected cats. It appears a year or more following the initial infection in an unknown proportion of infected animals. FIV has been identified in cats from all parts of the world. It is most prevalent in high density populations of free roaming cats (feral and pet), and is very uncommon in closed purebred catteries. Male cats are twice as likely to become infected as females. Older male cats adopted as feral or stray animals are at the highest risk of infection, therefore. The infection rate among freely roaming cats rises throughout life, and reaches levels ranging from less than 1% to 12% or more depending on the

  20. Zika Virus Infection and Microcephaly.

    Science.gov (United States)

    Millichap, J Gordon

    2016-01-01

    A Task Force established by the Brazil Ministry of Health investigated the possible association of microcephaly with Zika virus infection during pregnancy and a registry for microcephaly cases among women suspected to have had Zika virus infection during pregnancy.

  1. [Zika virus infection during pregnancy].

    Science.gov (United States)

    Picone, O; Vauloup-Fellous, C; D'Ortenzio, E; Huissoud, C; Carles, G; Benachi, A; Faye, A; Luton, D; Paty, M-C; Ayoubi, J-M; Yazdanpanah, Y; Mandelbrot, L; Matheron, S

    2016-05-01

    A Zika virus epidemic is currently ongoing in the Americas. This virus is linked to congenital infections with potential severe neurodevelopmental dysfunction. However, incidence of fetal infection and whether this virus is responsible of other fetal complications are still unknown. National and international public health authorities recommend caution and several prevention measures. Declaration of Zika virus infection is now mandatory in France. Given the available knowledge on Zika virus, we suggest here a review of the current recommendations for management of pregnancy in case of suspicious or infection by Zika virus in a pregnant woman.

  2. Parainfluenza Virus Infection.

    Science.gov (United States)

    Branche, Angela R; Falsey, Ann R

    2016-08-01

    Human parainfluenza viruses (HPIVs) are single-stranded, enveloped RNA viruses of the Paramyoviridaie family. There are four serotypes which cause respiratory illnesses in children and adults. HPIVs bind and replicate in the ciliated epithelial cells of the upper and lower respiratory tract and the extent of the infection correlates with the location involved. Seasonal HPIV epidemics result in a significant burden of disease in children and account for 40% of pediatric hospitalizations for lower respiratory tract illnesses (LRTIs) and 75% of croup cases. Parainfluenza viruses are associated with a wide spectrum of illnesses which include otitis media, pharyngitis, conjunctivitis, croup, tracheobronchitis, and pneumonia. Uncommon respiratory manifestations include apnea, bradycardia, parotitis, and respiratory distress syndrome and rarely disseminated infection. Immunity resulting from disease in childhood is incomplete and reinfection with HPIV accounts for 15% of respiratory illnesses in adults. Severe disease and fatal pneumonia may occur in elderly and immunocompromised adults. HPIV pneumonia in recipients of hematopoietic stem cell transplant (HSCT) is associated with 50% acute mortality and 75% mortality at 6 months. Though sensitive molecular diagnostics are available to rapidly diagnose HPIV infection, effective antiviral therapies are not available. Currently, treatment for HPIV infection is supportive with the exception of croup where the use of corticosteroids has been found to be beneficial. Several novel drugs including DAS181 appear promising in efforts to treat severe disease in immunocompromised patients, and vaccines to decrease the burden of disease in young children are in development. PMID:27486735

  3. Zika virus infections.

    Science.gov (United States)

    de Laval, F; Leparc-Goffart, I; Meynard, J-B; Daubigny, H; Simon, F; Briolant, S

    2016-05-01

    Since its discovery in 1947 in Uganda, the Zika virus (ZIKV) remained in the shadows emerging in 2007 in Micronesia, where hundreds of dengue-like syndromes were reported. Then, in 2013-2014, it was rife in French Polynesia, where the first neurological effects were observed. More recently, its arrival in Brazil was accompanied by an unusually high number of children with microcephaly born to mothers infected with ZIKV during the first trimester of pregnancy. In 2016, the World Health Organization declared ZIKV infection to be a public health emergency and now talks about a ZIKV pandemic. This review aims to summarize the current knowledge about ZIKV infection, successively addressing its transmission, epidemiology, clinical aspects, diagnosis, treatment, and prevention before discussing some perspectives. PMID:27412976

  4. 淋巴细胞脉络丛脑膜炎病毒快速核酸检测方法%Establishment of Nucleic Acid Assays for Rapid Detection of Lymphocytic Choriomeningitis Virus

    Institute of Scientific and Technical Information of China (English)

    熊炜; 林颖峥; 魏晓锋; 王艳; 张强; 李健; 胡建华; 黄忠荣

    2015-01-01

    In order to survey and conduct epidemiological investigation of lymphocytic choriomeningitis virus(LCMV) among wild and experimental rodent animals,RT-PCR assay and Real-time RT-PCR assay were established using TaqMan probe for LCMV with high sensitivity,specificity and stability for rapid detection of LCMV.%为加强口岸对进境野生及实验用啮齿类动物中淋巴细胞脉络丛脑膜炎病毒(LCMV)筛查和流行病学调查,本研究建立了RT-PCR和Real-time RT-PCR快速高通量检测LCMV的方法,证实两种核酸检测方法具有良好的特异性、灵敏性和稳定性,适于快速检测LCMV。

  5. Avian Influenza A Virus Infections in Humans

    Science.gov (United States)

    ... Past Newsletters Avian Influenza A Virus Infections in Humans Language: English Español Recommend on Facebook Tweet ... A Viruses Avian Influenza A Virus Infections in Humans Although avian influenza A viruses usually do not ...

  6. Toso regulates differentiation and activation of inflammatory dendritic cells during persistence-prone virus infection.

    Science.gov (United States)

    Lang, P A; Meryk, A; Pandyra, A A; Brenner, D; Brüstle, A; Xu, H C; Merches, K; Lang, F; Khairnar, V; Sharma, P; Funkner, P; Recher, M; Shaabani, N; Duncan, G S; Duhan, V; Homey, B; Ohashi, P S; Häussinger, D; Knolle, P A; Honke, N; Mak, T W; Lang, K S

    2015-01-01

    During virus infection and autoimmune disease, inflammatory dendritic cells (iDCs) differentiate from blood monocytes and infiltrate infected tissue. Following acute infection with hepatotropic viruses, iDCs are essential for re-stimulating virus-specific CD8(+) T cells and therefore contribute to virus control. Here we used the lymphocytic choriomeningitis virus (LCMV) model system to identify novel signals, which influence the recruitment and activation of iDCs in the liver. We observed that intrinsic expression of Toso (Faim3, FcμR) influenced the differentiation and activation of iDCs in vivo and DCs in vitro. Lack of iDCs in Toso-deficient (Toso(-/-)) mice reduced CD8(+) T-cell function in the liver and resulted in virus persistence. Furthermore, Toso(-/-) DCs failed to induce autoimmune diabetes in the rat insulin promoter-glycoprotein (RIP-GP) autoimmune diabetes model. In conclusion, we found that Toso has an essential role in the differentiation and maturation of iDCs, a process that is required for the control of persistence-prone virus infection. PMID:25257173

  7. Zika Virus Infection and Microcephaly

    Directory of Open Access Journals (Sweden)

    J. Gordon Millichap

    2016-03-01

    Full Text Available A Task Force established by the Brazil Ministry of Health investigated the possible association of microcephaly with Zika virus infection during pregnancy and a registry for microcephaly cases among women suspected to have had Zika virus infection during pregnancy.

  8. Conserved Residues in Lassa Fever Virus Z Protein Modulate Viral Infectivity at the Level of the Ribonucleoprotein▿

    OpenAIRE

    Capul, Althea A.; de la Torre, Juan Carlos; Buchmeier, Michael J.

    2011-01-01

    Arenaviruses are negative-strand RNA viruses that cause human diseases such as lymphocytic choriomeningitis, Bolivian hemorrhagic fever, and Lassa hemorrhagic fever. No licensed vaccines exist, and current treatment is limited to ribavirin. The prototypic arenavirus, lymphocytic choriomeningitis virus (LCMV), is a model for dissecting virus-host interactions in persistent and acute disease. The RING finger protein Z has been identified as the driving force of arenaviral budding and acts as th...

  9. Conserved Residues in Lassa Fever Virus Z Protein Modulate Viral Infectivity at the Level of the Ribonucleoprotein▿

    Science.gov (United States)

    Capul, Althea A.; de la Torre, Juan Carlos; Buchmeier, Michael J.

    2011-01-01

    Arenaviruses are negative-strand RNA viruses that cause human diseases such as lymphocytic choriomeningitis, Bolivian hemorrhagic fever, and Lassa hemorrhagic fever. No licensed vaccines exist, and current treatment is limited to ribavirin. The prototypic arenavirus, lymphocytic choriomeningitis virus (LCMV), is a model for dissecting virus-host interactions in persistent and acute disease. The RING finger protein Z has been identified as the driving force of arenaviral budding and acts as the viral matrix protein. While residues in Z required for viral budding have been described, residues that govern the Z matrix function(s) have yet to be fully elucidated. Because this matrix function is integral to viral assembly, we reasoned that this would be reflected in sequence conservation. Using sequence alignment, we identified several conserved residues in Z outside the RING and late domains. Nine residues were each mutated to alanine in Lassa fever virus Z. All of the mutations affected the expression of an LCMV minigenome and the infectivity of virus-like particles, but to greatly varying degrees. Interestingly, no mutations appeared to affect Z-mediated budding or association with viral GP. Our findings provide direct experimental evidence supporting a role for Z in the modulation of the activity of the viral ribonucleoprotein (RNP) complex and its packaging into mature infectious viral particles. PMID:21228230

  10. Conserved residues in Lassa fever virus Z protein modulate viral infectivity at the level of the ribonucleoprotein.

    Science.gov (United States)

    Capul, Althea A; de la Torre, Juan Carlos; Buchmeier, Michael J

    2011-04-01

    Arenaviruses are negative-strand RNA viruses that cause human diseases such as lymphocytic choriomeningitis, Bolivian hemorrhagic fever, and Lassa hemorrhagic fever. No licensed vaccines exist, and current treatment is limited to ribavirin. The prototypic arenavirus, lymphocytic choriomeningitis virus (LCMV), is a model for dissecting virus-host interactions in persistent and acute disease. The RING finger protein Z has been identified as the driving force of arenaviral budding and acts as the viral matrix protein. While residues in Z required for viral budding have been described, residues that govern the Z matrix function(s) have yet to be fully elucidated. Because this matrix function is integral to viral assembly, we reasoned that this would be reflected in sequence conservation. Using sequence alignment, we identified several conserved residues in Z outside the RING and late domains. Nine residues were each mutated to alanine in Lassa fever virus Z. All of the mutations affected the expression of an LCMV minigenome and the infectivity of virus-like particles, but to greatly varying degrees. Interestingly, no mutations appeared to affect Z-mediated budding or association with viral GP. Our findings provide direct experimental evidence supporting a role for Z in the modulation of the activity of the viral ribonucleoprotein (RNP) complex and its packaging into mature infectious viral particles. PMID:21228230

  11. Programmed death 1 protects from fatal circulatory failure during systemic virus infection of mice.

    Science.gov (United States)

    Frebel, Helge; Nindl, Veronika; Schuepbach, Reto A; Braunschweiler, Thomas; Richter, Kirsten; Vogel, Johannes; Wagner, Carsten A; Loffing-Cueni, Dominique; Kurrer, Michael; Ludewig, Burkhard; Oxenius, Annette

    2012-12-17

    The inhibitory programmed death 1 (PD-1)-programmed death ligand 1 (PD-L1) pathway contributes to the functional down-regulation of T cell responses during persistent systemic and local virus infections. The blockade of PD-1-PD-L1-mediated inhibition is considered as a therapeutic approach to reinvigorate antiviral T cell responses. Yet previous studies reported that PD-L1-deficient mice develop fatal pathology during early systemic lymphocytic choriomeningitis virus (LCMV) infection, suggesting a host protective role of T cell down-regulation. As the exact mechanisms of pathology development remained unclear, we set out to delineate in detail the underlying pathogenesis. Mice deficient in PD-1-PD-L1 signaling or lacking PD-1 signaling in CD8 T cells succumbed to fatal CD8 T cell-mediated immunopathology early after systemic LCMV infection. In the absence of regulation via PD-1, CD8 T cells killed infected vascular endothelial cells via perforin-mediated cytolysis, thereby severely compromising vascular integrity. This resulted in systemic vascular leakage and a consequential collapse of the circulatory system. Our results indicate that the PD-1-PD-L1 pathway protects the vascular system from severe CD8 T cell-mediated damage during early systemic LCMV infection, highlighting a pivotal physiological role of T cell down-regulation and suggesting the potential development of immunopathological side effects when interfering with the PD-1-PD-L1 pathway during systemic virus infections. PMID:23230000

  12. Risk of infections transmitted by arthropods and rodents in forestry workers.

    NARCIS (Netherlands)

    A.W. Moll van Charante; J. Groen (Jan); A.D.M.E. Osterhaus (Albert)

    1994-01-01

    textabstractOne hundred and fifty-one forestry workers and 151 matched office clerks were compared as to the presence of antibodies against Borelia burgdorferi, tick-borne encephalitis virus, Puumalavirus and lymphocytic choriomeningitis virus. Their occupational risks of being infected by Borrelia

  13. Virus-Induced Type I Interferon Deteriorates Control of Systemic Pseudomonas Aeruginosa Infection

    Directory of Open Access Journals (Sweden)

    Katja Merches

    2015-07-01

    Full Text Available Background: Type I interferon (IFN-I predisposes to bacterial superinfections, an important problem during viral infection or treatment with interferon-alpha (IFN-α. IFN-I-induced neutropenia is one reason for the impaired bacterial control; however there is evidence that more frequent bacterial infections during IFN-α-treatment occur independently of neutropenia. Methods: We analyzed in a mouse model, whether Pseudomonas aeruginosa control is influenced by co-infection with the lymphocytic choriomeningitis virus (LCMV. Bacterial titers, numbers of neutrophils and the gene-expression of liver-lysozyme-2 were determined during a 24 hours systemic infection with P. aeruginosa in wild-type and Ifnar-/- mice under the influence of LCMV or poly(I:C. Results: Virus-induced IFN-I impaired the control of Pseudomonas aeruginosa. This was associated with neutropenia and loss of lysozyme-2-expression in the liver, which had captured P. aeruginosa. A lower release of IFN-I by poly(I:C-injection also impaired the bacterial control in the liver and reduced the expression of liver-lysozyme-2. Low concentration of IFN-I after infection with a virulent strain of P. aeruginosa alone impaired the bacterial control and reduced lysozyme-2-expression in the liver as well. Conclusion: We found that during systemic infection with P. aeruginosa Kupffer cells quickly controlled the bacteria in cooperation with neutrophils. Upon LCMV-infection this cooperation was disturbed.

  14. Dengue Virus Infection in Africa

    OpenAIRE

    Amarasinghe, Ananda; Kuritsky, Joel N.; Letson, G. William; Margolis, Harold S

    2011-01-01

    Reported incidence of dengue has increased worldwide in recent decades, but little is known about its incidence in Africa. During 1960–2010, a total of 22 countries in Africa reported sporadic cases or outbreaks of dengue; 12 other countries in Africa reported dengue only in travelers. The presence of disease and high prevalence of antibody to dengue virus in limited serologic surveys suggest endemic dengue virus infection in all or many parts of Africa. Dengue is likely underrecognized and u...

  15. IL-10 Induces T Cell Exhaustion During Transplantation of Virus Infected Hearts

    Directory of Open Access Journals (Sweden)

    Asmae Gassa

    2016-03-01

    Full Text Available Background/Aims: Unexpected transmissions of viral pathogens during solid organ transplantation (SOT can result in severe, life-threatening diseases in transplant recipients. Immune activation contributes to disease onset. However mechanisms balancing the immune response against transmitted viral infection through organ transplantation remain unknown. Methods & Results: Here we found, using lymphocytic choriomeningitis virus (LCMV, that transplantation of LCMV infected hearts led to exhaustion of virus specific CD8+ T cells, viral persistence in organs and survival of graft and recipient. Genetic depletion of Interleukin-10 (IL-10 resulted in strong immune activation, graft dysfunction and death of mice, suggesting that IL-10 was a major regulator of CD8+ T cell exhaustion during SOT. In the presence of memory CD8+ T cells, virus could be controlled. However sufficient antiviral immune response resulted in acute rejection of transplanted heart. Conclusion: We found that virus transmitted via SOT could not be controlled by naïve mice recipients due to IL-10 mediated CD8+ T cell exhaustion which thereby prevented immunopathology and graft failure whereas memory mice recipients were able to control the virus and induced graft failure.

  16. Hepatitis Virus Infections in Poultry.

    Science.gov (United States)

    Yugo, Danielle M; Hauck, Ruediger; Shivaprasad, H L; Meng, Xiang-Jin

    2016-09-01

    Viral hepatitis in poultry is a complex disease syndrome caused by several viruses belonging to different families including avian hepatitis E virus (HEV), duck hepatitis B virus (DHBV), duck hepatitis A virus (DHAV-1, -2, -3), duck hepatitis virus Types 2 and 3, fowl adenoviruses (FAdV), and turkey hepatitis virus (THV). While these hepatitis viruses share the same target organ, the liver, they each possess unique clinical and biological features. In this article, we aim to review the common and unique features of major poultry hepatitis viruses in an effort to identify the knowledge gaps and aid the prevention and control of poultry viral hepatitis. Avian HEV is an Orthohepevirus B in the family Hepeviridae that naturally infects chickens and consists of three distinct genotypes worldwide. Avian HEV is associated with hepatitis-splenomegaly syndrome or big liver and spleen disease in chickens, although the majority of the infected birds are subclinical. Avihepadnaviruses in the family of Hepadnaviridae have been isolated from ducks, snow geese, white storks, grey herons, cranes, and parrots. DHBV evolved with the host as a noncytopathic form without clinical signs and rarely progressed to chronicity. The outcome for DHBV infection varies by the host's ability to elicit an immune response and is dose and age dependent in ducks, thus mimicking the pathogenesis of human hepatitis B virus (HBV) infections and providing an excellent animal model for human HBV. DHAV is a picornavirus that causes a highly contagious virus infection in ducks with up to 100% flock mortality in ducklings under 6 wk of age, while older birds remain unaffected. The high morbidity and mortality has an economic impact on intensive duck production farming. Duck hepatitis virus Types 2 and 3 are astroviruses in the family of Astroviridae with similarity phylogenetically to turkey astroviruses, implicating the potential for cross-species infections between strains. Duck astrovirus (DAstV) causes

  17. T-cell intrinsic expression of MyD88 is required for sustained expansion of the virus-specific CD8+ T-cell population in LCMV-infected mice

    DEFF Research Database (Denmark)

    Bartholdy, Christina; Christensen, Jeanette Erbo; Grujic, Mirjana;

    2009-01-01

    Acute infection with lymphocytic choriomeningitis virus (LCMV) normally results in robust clonal expansion of virus-specific CD8(+) T cells, which in turn control the primary infection. However, similar infection of myeloid differentiation factor 88 (MyD88)-deficient mice leads to a markedly...... is critical for a normal T-cell response to LCMV. In addition, it was found that expression of MyD88 is superfluous during early activation and proliferation of the antigen-activated CD8(+) T cells, but plays a critical role in the sustained expansion of the antigen-specific CD8(+) T-cell population during...... the primary T-cell response. Interestingly, a critical role for MyD88 was evident only under conditions of systemic infection with virus capable of causing prolonged infection, suggesting that MyD88 expression may function as an internal regulator of the threshold for antigen-driven, exhaustive...

  18. BK virus infection in human immunodeficiency virus-infected patients.

    Science.gov (United States)

    Ledesma, J; Muñoz, P; Garcia de Viedma, D; Cabrero, I; Loeches, B; Montilla, P; Gijon, P; Rodriguez-Sanchez, B; Bouza, E

    2012-07-01

    The aim of this study is to evaluate the prevalence of BK virus (BKV) infection in HIV-positive patients receiving highly active antiretroviral therapy (HAART) in our hospital. The presence of BKV was analysed in urine and plasma samples from 78 non-selected HIV-infected patients. Clinical data were recorded using a pre-established protocol. We used a nested PCR to amplify a specific region of the BKV T-large antigen. Positive samples were quantified using real-time PCR. Mean CD4 count in HIV-infected patients was 472 cells/mm3 and median HIV viral load was 500 cells/mm3 (74.3% vs 25.7%; p=0.007). Viruria was present in 21.7% of healthy controls (5 out of 23 samples, p=0.02). All viral loads were low (<100 copies/mL), and we could not find any association between BKV infection and renal or neurological manifestations. We provide an update on the prevalence of BKV in HIV-infected patients treated with HAART. BKV viruria was more common in HIV-infected patients; however, no role for BKV has been demonstrated in this population.

  19. Hepatic disorder in Zika virus infection

    Institute of Scientific and Technical Information of China (English)

    Viroj Wiwanitkit

    2016-01-01

    Zika virus infection is the present global problem. This arbovirus infection can cause acute ilness and affect fetus in utero. However, there can be other additional clinical manifestation including to the hepatic disorder. In this short commentary article, the author brielfy discusses on the liver problem due to Zika virus infection.

  20. CNS recruitment of CD8+ T lymphocytes specific for a peripheral virus infection triggers neuropathogenesis during polymicrobial challenge.

    Directory of Open Access Journals (Sweden)

    Christine M Matullo

    2011-12-01

    Full Text Available Although viruses have been implicated in central nervous system (CNS diseases of unknown etiology, including multiple sclerosis and amyotrophic lateral sclerosis, the reproducible identification of viral triggers in such diseases has been largely unsuccessful. Here, we explore the hypothesis that viruses need not replicate in the tissue in which they cause disease; specifically, that a peripheral infection might trigger CNS pathology. To test this idea, we utilized a transgenic mouse model in which we found that immune cells responding to a peripheral infection are recruited to the CNS, where they trigger neurological damage. In this model, mice are infected with both CNS-restricted measles virus (MV and peripherally restricted lymphocytic choriomeningitis virus (LCMV. While infection with either virus alone resulted in no illness, infection with both viruses caused disease in all mice, with ∼50% dying following seizures. Co-infection resulted in a 12-fold increase in the number of CD8+ T cells in the brain as compared to MV infection alone. Tetramer analysis revealed that a substantial proportion (>35% of these infiltrating CD8+ lymphocytes were LCMV-specific, despite no detectable LCMV in CNS tissues. Mechanistically, CNS disease was due to edema, induced in a CD8-dependent but perforin-independent manner, and brain herniation, similar to that observed in mice challenged intracerebrally with LCMV. These results indicate that T cell trafficking can be influenced by other ongoing immune challenges, and that CD8+ T cell recruitment to the brain can trigger CNS disease in the apparent absence of cognate antigen. By extrapolation, human CNS diseases of unknown etiology need not be associated with infection with any particular agent; rather, a condition that compromises and activates the blood-brain barrier and adjacent brain parenchyma can render the CNS susceptible to pathogen-independent immune attack.

  1. Neuropathology of Zika Virus Infection

    Science.gov (United States)

    Solomon, Isaac H; Milner, Danny A; Folkerth, Rebecca D

    2016-01-01

    Zika virus (ZIKV) is a member of the Flaviviridae family that had been associated only with mild disease prior to the 2015 outbreak in Brazil. A dramatic increase in reported cases of microcephaly and Guillain-Barré syndrome during this time prompted significant research into possible associations with ZIKV and its neurotropic properties. Infection of neural progenitor cells and organoids have been shown to induce apoptosis and dysregulation of growth, and mouse studies have demonstrated viral replication in brain tissue in adults, as well as vertical transmission resulting in embryonic brain abnormalities. Large case series of clinical and radiological findings of congenital ZIKV infection have begun to be published; however, pathology reports have been limited to two case reports and two small case series. Thus far, the findings have largely been restricted to the brain and include diffuse grey and white matter involvement consisting of dystrophic calcifications, gliosis, microglial nodules, neuronophagia, and scattered lymphocytes. Mild chronic villitis was observed in the placental tissue in some cases, and the remaining organs were essentially uninvolved. Larger, systematic studies, including correlation of histological findings with gestational age at the time of maternal infection, will be required to determine the full range of Zika virus-induced abnormalities and to help guide future clinical decision making. PMID:27525286

  2. Models of dengue virus infection.

    Science.gov (United States)

    Bente, Dennis A; Rico-Hesse, Rebeca

    2006-01-01

    The need for models of dengue disease has reached a pinnacle as the transmission of this mosquito-borne virus has increased dramatically. Little is known about the mechanisms that lead to dengue fever and its more severe form, dengue hemorrhagic fever; this is owing to the fact that only humans show signs of disease. In the past 5 years, research has better identified the initial target cells of infection, and this has led to the development of models of infection in primary human cell cultures. Mouse-human chimeras, containing these target cells, have also led to progress in developing animal models. These advances should soon end the stalemate in testing antivirals and vaccine preparations that had necessarily been done in incomplete or irrelevant models. PMID:18087566

  3. Acute otitis media and respiratory virus infections.

    Science.gov (United States)

    Ruuskanen, O; Arola, M; Putto-Laurila, A; Mertsola, J; Meurman, O; Viljanen, M K; Halonen, P

    1989-02-01

    We studied the association of acute otitis media with different respiratory virus infections in a pediatric department on the basis of epidemics between 1980 and 1985. Altogether 4524 cases of acute otitis media were diagnosed. The diagnosis was confirmed by tympanocentesis in 3332 ears. Respiratory virus infection was diagnosed during the same period in 989 patients by detecting viral antigen in nasopharyngeal mucus. There was a significant correlation between acute otitis media and respiratory virus epidemics, especially respiratory syncytial virus epidemics. There was no significant correlation between outbreaks of other respiratory viruses and acute otitis media. Acute otitis media was diagnosed in 57% of respiratory syncytial virus, 35% of influenza A virus, 33% of parainfluenza type 3 virus, 30% of adenovirus, 28% of parainfluenza type 1 virus, 18% of influenza B virus and 10% of parainfluenza type 2 virus infections. These observations show a clear association of respiratory virus infections with acute otitis media. In this study on hospitalized children Haemophilus influenzae strains were the most common bacteriologic pathogens in middle ear fluid, occurring in 19% of cases. Streptococcus pneumoniae was present in 16% and Branhamella catarrhalis in 7% of cases. There was no association between specific viruses and bacteria observed in this study.

  4. Zika Virus Infection and Zika Fever: Frequently Asked Questions

    Science.gov (United States)

    ... Frequently asked questions Updated: 25 March 2016 ABOUT ZIKA What is Zika virus infection? Zika virus infection is caused by ... possible to characterize the disease better. How is Zika virus transmitted? Zika virus is transmitted to people ...

  5. Modeling Zika Virus Infection in Mice.

    Science.gov (United States)

    Rossi, Shannan L; Vasilakis, Nikos

    2016-07-01

    Understanding the link between Zika virus (ZIKV) infection and microcephaly requires in vivo models of ZIKV infection in pregnant adults and fetuses. Three studies recently generated such mouse models of ZIKV infection, which corroborate previous in vitro evidence linking ZIKV infection and apoptosis induction in neurons and progenitors to microcephaly. PMID:27392219

  6. Medicinal herbs for hepatitis C virus infection

    DEFF Research Database (Denmark)

    Liu, Jianping; Manheimer, Eric; Tsutani, Kiichiro;

    2003-01-01

    The aim of this study was to assess beneficial and harmful effects of medicinal herbs for hepatitis C virus (HCV) infection.......The aim of this study was to assess beneficial and harmful effects of medicinal herbs for hepatitis C virus (HCV) infection....

  7. Medicinal herbs for hepatitis C virus infection

    DEFF Research Database (Denmark)

    Liu, J P; Manheimer, E; Tsutani, K;

    2001-01-01

    Hepatitis C virus (HCV) infection is a serious health problem world-wide. Medicinal herbs are increasingly being used for hepatitis C.......Hepatitis C virus (HCV) infection is a serious health problem world-wide. Medicinal herbs are increasingly being used for hepatitis C....

  8. Role of macrophages during Theiler's virus infection.

    OpenAIRE

    Rossi, C P; Delcroix, M; Huitinga, I.; McAllister, A; Van Rooijen, N.; E. Claassen; Brahic, M

    1997-01-01

    Theiler's virus, a murine picornavirus, causes a persistent infection of the central nervous system with chronic inflammation and primary demyelination. We examined the nature of infected cells at different times postinoculation (p.i.) with a combined immunocytochemistry-in situ hybridization assay. The virus was found in the gray matter of the brain, mostly in neurons, during the first week p.i. During the following weeks, the virus was present in the spinal cord, first in the gray and white...

  9. Detection of Lassa virus RNA in specimens from patients with Lassa fever by using the polymerase chain reaction.

    OpenAIRE

    Lunkenheimer, K; Hufert, F. T.; Schmitz, H.

    1990-01-01

    Suitable oligonucleotide primers and probes were synthesized to amplify Lassa virus (Josiah strain)-specific nucleoprotein and glycoprotein gene fragments by using reverse transcription combined with the polymerase chain reaction (PCR). Our primers did not amplify the related lymphocytic choriomeningitis virus. By using PCR, about 50 50% tissue culture infective doses could be detected in the supernatant of infected cells. Furthermore, in all five serum specimens and four of five urine specim...

  10. Glomerulonephritis secondary to Barmah Forest virus infection.

    Science.gov (United States)

    Katz, I A; Hale, G E; Hudson, B J; Ibels, L S; Eckstein, R P; Dermott, P L

    1997-07-01

    Clinical infection with Barmah Forest virus (BFV) is becoming increasingly recognised with serological testing. We report the first case of glomerulonephritis after BFV infection. The patient required diuretic and antihypertensive therapy, but made an almost complete recovery. BFV infection should be considered in the differential diagnosis of glomerulonephritis. PMID:9236755

  11. Radiation Inactivation of Viruses in Infected Products

    International Nuclear Information System (INIS)

    Full text: The effects of gamma radiation on foot-and-mouth disease virus in vitro and in situ have been studied. The data so far obtained show that a dose of 2 Mrad is required to inactivate virus in infected animal carcasses. But the dose may adversely affect the organoleptic quality of the meat. Experiments in vitro and in situ are necessary to study the effects of ionizing radiation on other viruses, such as rinderpest, swine fever and African swine fever-viruses, associated with animal products. Radiation may offer a possible means of eliminating the virus titre in many animal products and solve consequent quarantine problems. (author)

  12. Interferon-γ Inhibits Ebola Virus Infection.

    Directory of Open Access Journals (Sweden)

    Bethany A Rhein

    Full Text Available Ebola virus outbreaks, such as the 2014 Makona epidemic in West Africa, are episodic and deadly. Filovirus antivirals are currently not clinically available. Our findings suggest interferon gamma, an FDA-approved drug, may serve as a novel and effective prophylactic or treatment option. Using mouse-adapted Ebola virus, we found that murine interferon gamma administered 24 hours before or after infection robustly protects lethally-challenged mice and reduces morbidity and serum viral titers. Furthermore, we demonstrated that interferon gamma profoundly inhibits Ebola virus infection of macrophages, an early cellular target of infection. As early as six hours following in vitro infection, Ebola virus RNA levels in interferon gamma-treated macrophages were lower than in infected, untreated cells. Addition of the protein synthesis inhibitor, cycloheximide, to interferon gamma-treated macrophages did not further reduce viral RNA levels, suggesting that interferon gamma blocks life cycle events that require protein synthesis such as virus replication. Microarray studies with interferon gamma-treated human macrophages identified more than 160 interferon-stimulated genes. Ectopic expression of a select group of these genes inhibited Ebola virus infection. These studies provide new potential avenues for antiviral targeting as these genes that have not previously appreciated to inhibit negative strand RNA viruses and specifically Ebola virus infection. As treatment of interferon gamma robustly protects mice from lethal Ebola virus infection, we propose that interferon gamma should be further evaluated for its efficacy as a prophylactic and/or therapeutic strategy against filoviruses. Use of this FDA-approved drug could rapidly be deployed during future outbreaks.

  13. Ebola Virus Infection Modelling and Identifiability Problems

    Directory of Open Access Journals (Sweden)

    Van-Kinh eNguyen

    2015-04-01

    Full Text Available The recent outbreaks of Ebola virus (EBOV infections have underlined the impact of the virus as a major threat for human health. Due to the high biosafety classification of EBOV (level 4, basic research is very limited. Therefore, the development of new avenues of thinking to advance quantitative comprehension of the virus and its interaction with the host cells is urgently neededto tackle this lethal disease. Mathematical modelling of the EBOV dynamics can be instrumental to interpret Ebola infection kinetics on quantitative grounds. To the best of our knowledge, a mathematical modelling approach to unravel the interaction between EBOV and the host cells isstill missing. In this paper, a mathematical model based on differential equations is used to represent the basic interactions between EBOV and wild-type Vero cells in vitro. Parameter sets that represent infectivity of pathogens are estimated for EBOV infection and compared with influenza virus infection kinetics. The average infecting time of wild-type Vero cells in EBOV is slower than in influenza infection. Simulation results suggest that the slow infecting time of EBOV could be compensated by its efficient replication. This study reveals several identifiability problems and what kind of experiments are necessary to advance the quantification of EBOV infection. A first mathematical approach of EBOV dynamics and the estimation of standard parametersin viral infections kinetics is the key contribution of this work, paving the way for future modelling work on EBOV infection.

  14. Hepatitis C virus infection in Nigerians

    Directory of Open Access Journals (Sweden)

    O S Ejiofor

    2010-01-01

    Full Text Available Background: Hepatitis C virus is a chronic lifelong infection in the majority of patients who are infected with the virus. Not much is known and written/published about this virus in Nigeria. Objective: To assess the status of hepatitis C virus infection in Nigeria. Materials and method:Sources of information were mainly from published works in and outside Nigeria. The information was extracted over a period of 12 months from January to December 2009. Results: So far the prevalence of hepatitis C. virus infection is increasing in Nigeria, ranging from 4.7-5% in Ilorin, to 5.3-6.6% in Enugu, to 11% in Ibadan and 20% in Benin. Children and adults are all at risk of being infected especially sickle cell disease patients. Others include those who are exposed to the common risk factors like Blood transfusion, haemodialyisis, recycling of syringes and needles, sexual promiscuity. Conclusion: Reduction in the Hepatitis C virus infection could be achieved by Health education campaign of the general public and by support from government and non-governmental organizations for the to provision of antiviral and immunostimulatory drugs free of charge for those already infected.

  15. Dengue Virus Infection Perturbs Lipid Homeostasis in Infected Mosquito Cells

    Energy Technology Data Exchange (ETDEWEB)

    Perera, Rushika M.; Riley, Catherine; Isaac, Georgis; Hopf- Jannasch, Amber; Moore, Ronald J.; Weitz, Karl K.; Pasa-Tolic, Ljiljana; Metz, Thomas O.; Adamec, Jiri; Kuhn, Richard J.

    2012-03-22

    Dengue virus causes {approx}50-100 million infections per year and thus is considered one of the most aggressive arthropod-borne human pathogen worldwide. During its replication, dengue virus induces dramatic alterations in the intracellular membranes of infected cells. This phenomenon is observed both in human and vector-derived cells. Using high-resolution mass spectrometry of mosquito cells, we show that this membrane remodeling is directly linked to a unique lipid repertoire induced by dengue virus infection. Specifically, 15% of the metabolites detected were significantly different between DENV infected and uninfected cells while 85% of the metabolites detected were significantly different in isolated replication complex membranes. Furthermore, we demonstrate that intracellular lipid redistribution induced by the inhibition of fatty acid synthase, the rate-limiting enzyme in lipid biosynthesis, is sufficient for cell survival but is inhibitory to dengue virus replication. Lipids that have the capacity to destabilize and change the curvature of membranes as well as lipids that change the permeability of membranes are enriched in dengue virus infected cells. Several sphingolipids and other bioactive signaling molecules that are involved in controlling membrane fusion, fission, and trafficking as well as molecules that influence cytoskeletal reorganization are also up regulated during dengue infection. These observations shed light on the emerging role of lipids in shaping the membrane and protein environments during viral infections and suggest membrane-organizing principles that may influence virus-induced intracellular membrane architecture.

  16. Human immunodeficiency virus infection and pneumothorax

    OpenAIRE

    Terzi, Eirini; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Tsiouda, Theodora; Madesis, Athanasios; Karaiskos, Theodoros; Zarogoulidis, Paul

    2014-01-01

    Pneumothorax is a serious and relatively frequent complication of human immunodeficiency virus (HIV) infection that may associate with increased morbidity and mortality and may prove difficult to manage, especially in patients with acquired immunodeficiency syndrome (AIDS).

  17. Life-Threatening Sochi Virus Infections, Russia.

    Science.gov (United States)

    Kruger, Detlev H; Tkachenko, Evgeniy A; Morozov, Vyacheslav G; Yunicheva, Yulia V; Pilikova, Olga M; Malkin, Gennadiy; Ishmukhametov, Aydar A; Heinemann, Patrick; Witkowski, Peter T; Klempa, Boris; Dzagurova, Tamara K

    2015-12-01

    Sochi virus was recently identified as a new hantavirus genotype carried by the Black Sea field mouse, Apodemus ponticus. We evaluated 62 patients in Russia with Sochi virus infection. Most clinical cases were severe, and the case-fatality rate was as high as 14.5%.

  18. Pathogenesis of hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Infection with hepatitis B virus (HBV) leads to a wide spectrum of clinical presentations ranging from an asymptomatic carrier state to self-limited acute or fulminant hepatitis to chronic hepatitis with progression to cirrhosis and hepatocellular carcinoma. Infection with HBV is one of the most common viral diseases affecting man. Both viral factors as well as the host immune response have been implicated in the pathogenesis and clinical outcome of HBV infection. In this review, we will discuss the impact of virus-host interactions for the pathogenesis of HBV infection and liver disease. These interactions include the relevance of naturally occurring viral variants for clinical disease, the role of virus-induced apoptosis for HBV-induced liver cell injury and the impact of antiviral immune responses for outcome of infection.

  19. Virus infections of honeybees Apis Mellifera

    Directory of Open Access Journals (Sweden)

    Giuseppina Tantillo

    2015-09-01

    Full Text Available The health and vigour of honeybee colonies are threatened by numerous parasites (such as Varroa destructor and Nosema spp. and pathogens, including viruses, bacteria, protozoa. Among honeybee pathogens, viruses are one of the major threats to the health and wellbeing of honeybees and cause serious concern for researchers and beekeepers. To tone down the threats posed by these invasive organisms, a better understanding of bee viral infections will be of crucial importance in developing effective and environmentally benign disease control strategies. Here we summarize recent progress in the understanding of the morphology, genome organization, transmission, epidemiology and pathogenesis of eight honeybee viruses: Deformed wing virus (DWV and Kakugo virus (KV; Sacbrood virus (SBV; Black Queen cell virus (BQCV; Acute bee paralysis virus (ABPV; Kashmir bee virus (KBV; Israeli Acute Paralysis Virus (IAPV; Chronic bee paralysis virus (CBPV. The review has been designed to provide researchers in the field with updated information about honeybee viruses and to serve as a starting point for future research.

  20. Virus Infections of Honeybees Apis Mellifera

    Science.gov (United States)

    Tantillo, Giuseppina; Bottaro, Marilisa; Di Pinto, Angela; Martella, Vito; Di Pinto, Pietro

    2015-01-01

    The health and vigour of honeybee colonies are threatened by numerous parasites (such as Varroa destructor and Nosema spp.) and pathogens, including viruses, bacteria, protozoa. Among honeybee pathogens, viruses are one of the major threats to the health and well-being of honeybees and cause serious concern for researchers and beekeepers. To tone down the threats posed by these invasive organisms, a better understanding of bee viral infections will be of crucial importance in developing effective and environmentally benign disease control strategies. Here we summarize recent progress in the understanding of the morphology, genome organization, transmission, epidemiology and pathogenesis of eight honeybee viruses: Deformed wing virus (DWV) and Kakugo virus (KV); Sacbrood virus (SBV); Black Queen cell virus (BQCV); Acute bee paralysis virus (ABPV); Kashmir bee virus (KBV); Israeli Acute Paralysis Virus (IAPV); Chronic bee paralysis virus (CBPV). The review has been designed to provide researchers in the field with updated information about honeybee viruses and to serve as a starting point for future research. PMID:27800411

  1. Virus Infection-Induced Bronchial Asthma Exacerbation

    Directory of Open Access Journals (Sweden)

    Mutsuo Yamaya

    2012-01-01

    Full Text Available Infection with respiratory viruses, including rhinoviruses, influenza virus, and respiratory syncytial virus, exacerbates asthma, which is associated with processes such as airway inflammation, airway hyperresponsiveness, and mucus hypersecretion. In patients with viral infections and with infection-induced asthma exacerbation, inflammatory mediators and substances, including interleukins (ILs, leukotrienes and histamine, have been identified in the airway secretions, serum, plasma, and urine. Viral infections induce an accumulation of inflammatory cells in the airway mucosa and submucosa, including neutrophils, lymphocytes and eosinophils. Viral infections also enhance the production of inflammatory mediators and substances in airway epithelial cells, mast cells, and other inflammatory cells, such as IL-1, IL-6, IL-8, GM-CSF, RANTES, histamine, and intercellular adhesion molecule-1. Viral infections affect the barrier function of the airway epithelial cells and vascular endothelial cells. Recent reports have demonstrated augmented viral production mediated by an impaired interferon response in the airway epithelial cells of asthma patients. Several drugs used for the treatment of bronchial asthma reduce viral and pro-inflammatory cytokine release from airway epithelial cells infected with viruses. Here, I review the literature on the pathogenesis of the viral infection-induced exacerbation of asthma and on the modulation of viral infection-induced airway inflammation.

  2. Controversies about occult hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    Ersan Ozaslan; Tugrul Purnak

    2009-01-01

    We read with great interest the paper written by Shi et al, reviewing the molecular characteristics and stages of chronic hepatitis B virus (HBV) infection. We think that some points in the definition of occult HBV infection (OBI) and their conclusion about the management of OBI may need further considerations.

  3. Inhibition of enveloped viruses infectivity by curcumin.

    Directory of Open Access Journals (Sweden)

    Tzu-Yen Chen

    Full Text Available Curcumin, a natural compound and ingredient in curry, has antiinflammatory, antioxidant, and anticarcinogenic properties. Previously, we reported that curcumin abrogated influenza virus infectivity by inhibiting hemagglutination (HA activity. This study demonstrates a novel mechanism by which curcumin inhibits the infectivity of enveloped viruses. In all analyzed enveloped viruses, including the influenza virus, curcumin inhibited plaque formation. In contrast, the nonenveloped enterovirus 71 remained unaffected by curcumin treatment. We evaluated the effects of curcumin on the membrane structure using fluorescent dye (sulforhodamine B; SRB-containing liposomes that mimic the viral envelope. Curcumin treatment induced the leakage of SRB from these liposomes and the addition of the influenza virus reduced the leakage, indicating that curcumin disrupts the integrity of the membranes of viral envelopes and of liposomes. When testing liposomes of various diameters, we detected higher levels of SRB leakage from the smaller-sized liposomes than from the larger liposomes. Interestingly, the curcumin concentration required to reduce plaque formation was lower for the influenza virus (approximately 100 nm in diameter than for the pseudorabies virus (approximately 180 nm and the vaccinia virus (roughly 335 × 200 × 200 nm. These data provide insights on the molecular antiviral mechanisms of curcumin and its potential use as an antiviral agent for enveloped viruses.

  4. Prevalence and prognostic significance of infection with TT virus in patients infected with human immunodeficiency virus

    DEFF Research Database (Denmark)

    Christensen, JK; Eugen-Olsen, Jesper; Sørensen, M;

    2000-01-01

    No clear association between human disease and TT virus (TTV) has been documented. A possible pathogenic role of TTV was investigated in patients infected with human immunodeficiency virus (HIV). TTV serum concentrations were estimated in 185 HIV-infected patients by dilution polymerase chain...

  5. Epstein-Barr virus infection mechanisms

    Institute of Scientific and Technical Information of China (English)

    Liudmila S. Chesnokova; Lindsey M. Hutt-Fletcher

    2014-01-01

    Epstein-Barr virus (EBV) infection occurs by distinct mechanisms across different cell types. EBV infection of B cellsin vitro minimally requires 5 viral glycoproteins and 2 cellular proteins. By contrast, infection of epithelial cells requires a minimum of 3 viral glycoproteins, which are capable of interacting with one or more of 3 different celular proteins. The ful complement of proteins involved in entry into al cel types capable of being infectedin vivo is unknown. This review discusses the events that occur when the virus is delivered into the cytoplasm of a cel, the players known to be involved in these events, and the ways in which these players are thought to function.

  6. Immune Response to Ebola Virus Infection

    Directory of Open Access Journals (Sweden)

    Alain Alonso Remedios

    2016-06-01

    Full Text Available Ebola virus belongs to the family Filoviridae and causes a highly lethal hemorrhagic fever. Affected patients show an impaired immune response as a result of the evasion mechanisms employed by the virus. Cathepsin is an enzyme present in the granules of phagocytes which cleaves viral surface glycoproteins, allowing virus entry into the host cell. In addition, this virus is resistant to the antiviral effects of type I interferon, promotes the synthesis of proinflammatory cytokines and induces apoptosis of monocytes and lymphocytes. It also induces an incomplete activation of dendritic cells, thus avoiding the presentation of viral antigens. Although specific antibodies are produced after the first week, their neutralizing capacity is doubtful. The virus evades the immune response and replicates uncontrollably in the host. This paper aims to summarize the main characteristics of the immune response to Ebola virus infection.

  7. Animal Models of Dengue Virus Infection

    OpenAIRE

    Eva Harris; Simona Zompi

    2012-01-01

    The development of animal models of dengue virus (DENV) infection and disease has been challenging, as epidemic DENV does not naturally infect non-human species. Non-human primates (NHPs) can sustain viral replication in relevant cell types and develop a robust immune response, but they do not develop overt disease. In contrast, certain immunodeficient mouse models infected with mouse-adapted DENV strains show signs of severe disease similar to the ‘vascular-leak’ syndrome seen in severe deng...

  8. Autoimmune pathogenesis in dengue virus infection.

    Science.gov (United States)

    Lin, Chiou-Feng; Wan, Shu-Wen; Cheng, Hsien-Jen; Lei, Huan-Yao; Lin, Yee-Shin

    2006-01-01

    The pathogenic mechanisms of dengue hemorrhagic fever and dengue shock syndrome (DHF/DSS) caused by dengue virus (DV) infection remain unresolved. Patients with DHF/DSS are characterized by several manifestations, including severe thrombocytopenia, vascular leakage, and hepatomegaly. In addition to the effect of virus load and virus variation, abnormal immune responses of the host after DV infection may also account for the progression of DHF/DSS. Actually, viral autoimmunity is involved in the pathogenesis of numerous viral infections, such as human immunodeficiency virus, human hepatitis C virus, human cytomegalovirus, herpes simplex virus, Epstein- Barr virus, and DV. In this review, we discuss the implications of autoimmunity in dengue pathogenesis. Antibodies directed against DV nonstructural protein 1 (NS1) showed cross-reactivity with human platelets and endothelial cells, which lead to platelet and endothelial cell damage and inflammatory activation. Based on these findings, we hypothesize that anti-DV NS1 is involved in the pathogenesis of DF and DHF/DSS, and this may provide important information in dengue vaccine development.

  9. Deficiency of the B Cell-Activating Factor Receptor Results in Limited CD169+ Macrophage Function during Viral Infection

    OpenAIRE

    Xu, Haifeng C.; Huang, Jun; Khairnar, Vishal; Duhan, Vikas; Pandyra, Aleksandra A; Grusdat, Melanie; Shinde, Prashant; McIlwain, David R.; Maney, Sathish Kumar; Gommerman, Jennifer; Löhning, Max; Ohashi, Pamela S.; Mak, Tak W; Pieper, Kathrin; Sic, Heiko

    2015-01-01

    The B cell-activating factor (BAFF) is critical for B cell development and humoral immunity in mice and humans. While the role of BAFF in B cells has been widely described, its role in innate immunity remains unknown. Using BAFF receptor (BAFFR)-deficient mice, we characterized BAFFR-related innate and adaptive immune functions following infection with vesicular stomatitis virus (VSV) and lymphocytic choriomeningitis virus (LCMV). We identified a critical role for BAFFR signaling in the gener...

  10. Multiple infections of rodents with zoonotic pathogens in Austria.

    Science.gov (United States)

    Schmidt, Sabrina; Essbauer, Sandra S; Mayer-Scholl, Anne; Poppert, Sven; Schmidt-Chanasit, Jonas; Klempa, Boris; Henning, Klaus; Schares, Gereon; Groschup, Martin H; Spitzenberger, Friederike; Richter, Dania; Heckel, Gerald; Ulrich, Rainer G

    2014-07-01

    Rodents are important reservoirs for a large number of zoonotic pathogens. We examined the occurrence of 11 viral, bacterial, and parasitic agents in rodent populations in Austria, including three different hantaviruses, lymphocytic choriomeningitis virus, orthopox virus, Leptospira spp., Borrelia spp., Rickettsia spp., Bartonella spp., Coxiella burnetii, and Toxoplasma gondii. In 2008, 110 rodents of four species (40 Clethrionomys glareolus, 29 Apodemus flavicollis, 26 Apodemus sylvaticus, and 15 Microtus arvalis) were trapped at two rural sites in Lower Austria. Chest cavity fluid and samples of lung, spleen, kidney, liver, brain, and ear pinna skin were collected. We screened selected tissue samples for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, Leptospira, Borrelia, Rickettsia, Bartonella spp., C. burnetii, and T. gondii by RT-PCR/PCR and detected nucleic acids of Tula hantavirus, Leptospira spp., Borrelia afzelii, Rickettsia spp., and different Bartonella species. Serological investigations were performed for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, and Rickettsia spp. Here, Dobrava-Belgrade hantavirus-, Tula hantavirus-, lymphocytic choriomeningitis virus-, orthopox virus-, and rickettsia-specific antibodies were demonstrated. Puumala hantavirus, C. burnetii, and T. gondii were neither detected by RT-PCR/PCR nor by serological methods. In addition, multiple infections with up to three pathogens were shown in nine animals of three rodent species from different trapping sites. In conclusion, these results show that rodents in Austria may host multiple zoonotic pathogens. Our observation raises important questions regarding the interactions of different pathogens in the host, the countermeasures of the host's immune system, the impact of the host-pathogen interaction on the fitness of the host, and the spread of infectious agents among wild rodents and from those to other animals or humans.

  11. Multiple infections of rodents with zoonotic pathogens in Austria.

    Science.gov (United States)

    Schmidt, Sabrina; Essbauer, Sandra S; Mayer-Scholl, Anne; Poppert, Sven; Schmidt-Chanasit, Jonas; Klempa, Boris; Henning, Klaus; Schares, Gereon; Groschup, Martin H; Spitzenberger, Friederike; Richter, Dania; Heckel, Gerald; Ulrich, Rainer G

    2014-07-01

    Rodents are important reservoirs for a large number of zoonotic pathogens. We examined the occurrence of 11 viral, bacterial, and parasitic agents in rodent populations in Austria, including three different hantaviruses, lymphocytic choriomeningitis virus, orthopox virus, Leptospira spp., Borrelia spp., Rickettsia spp., Bartonella spp., Coxiella burnetii, and Toxoplasma gondii. In 2008, 110 rodents of four species (40 Clethrionomys glareolus, 29 Apodemus flavicollis, 26 Apodemus sylvaticus, and 15 Microtus arvalis) were trapped at two rural sites in Lower Austria. Chest cavity fluid and samples of lung, spleen, kidney, liver, brain, and ear pinna skin were collected. We screened selected tissue samples for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, Leptospira, Borrelia, Rickettsia, Bartonella spp., C. burnetii, and T. gondii by RT-PCR/PCR and detected nucleic acids of Tula hantavirus, Leptospira spp., Borrelia afzelii, Rickettsia spp., and different Bartonella species. Serological investigations were performed for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, and Rickettsia spp. Here, Dobrava-Belgrade hantavirus-, Tula hantavirus-, lymphocytic choriomeningitis virus-, orthopox virus-, and rickettsia-specific antibodies were demonstrated. Puumala hantavirus, C. burnetii, and T. gondii were neither detected by RT-PCR/PCR nor by serological methods. In addition, multiple infections with up to three pathogens were shown in nine animals of three rodent species from different trapping sites. In conclusion, these results show that rodents in Austria may host multiple zoonotic pathogens. Our observation raises important questions regarding the interactions of different pathogens in the host, the countermeasures of the host's immune system, the impact of the host-pathogen interaction on the fitness of the host, and the spread of infectious agents among wild rodents and from those to other animals or humans. PMID:24915446

  12. Influenza virus infection, ozone exposure, and fibrogenesis.

    Science.gov (United States)

    Jakab, G J; Bassett, D J

    1990-05-01

    Oxidant exposure following chemically induced lung injury exacerbates the tendency to develop pulmonary fibrosis. Influenza virus pneumonitis causes severe acute lung damage that, upon resolution, is followed by a persistent alveolitis and parenchymal changes characterized by patchy interstitial pneumonia and collagen deposition in the affected areas. To determine whether oxidant exposure exacerbates the virus-induced alveolitis and residual lung damage, mice were infected by aerosol inhalation with influenza A virus and continuously exposed to 0.5 ppm ozone or ambient air. Noninfected control mice were exposed to either ambient air or ozone. On various days during the first month after infection, groups of mice were sacrificed and their lungs assessed for acute injury (lung lavage albumin, total and differential cell counts, wet/dry ratios, and morphometry). At 30, 60, 90, and 120 days after infection, groups of mice were sacrificed for total and differential lavage cell counts, lung hydroxyproline content, and morphometric analysis. Ozone exposure did not alter the proliferation of virus in the lungs as quantitated by infectious virus titers of lung homogenates at 1, 4, 7, 10, and 15 days after virus infection but mitigated the virus-induced acute lung injury by approximately 50%. After Day 30 a shift in the character of the pulmonary lesions was observed in that continuous exposure to ozone potentiated the postinfluenzal alveolitis and structural changes in the lung parenchyma. Additional studies suggest that the mechanism for the enhanced postinfluenzal lung damage may be related to the oxidant impairing the repair process of the acute influenzal lung damage. These data demonstrate that ozone exposure mitigates acute virus-induced lung injury and potentiates residual lung damage. PMID:2339849

  13. Effect of attenuated viral vaccines on suckling mice infected with LCMV.

    Science.gov (United States)

    Csatáry, L K; Szeri, I; Bános, Z; Anderlik, P; Nász, I

    1986-01-01

    A single intraperitoneal treatment with live Newcastle Disease Virus (NDV) containing attenuated NDV vaccine, and with live infectious bursal disease virus (IBDV) containing attenuated IBDV vaccine, one day before intracerebral infection with lymphocytic choriomeningitis virus (LCMV) increased, whereas a similar treatment with inactivated NDV or IBDV vaccine did not influence the death rate of suckling mice from experimental lymphocytic choriomeningitis. Thus the attenuated live vaccine stimulated, whereas the inactivated ones failed to affect the cell-mediated immune response to LCMV. Control studies set up with the supernatant of plain tissue culture routinely used for the propagation of IBDV have shown that unlike the attenuated NDV vaccine, the immunostimulatory action is associated not so much with the virus itself, as with an as yet unidentified component of the tissue culture supernatant.

  14. Increased tolerance and resistance to virus infections

    OpenAIRE

    Barbara Locke; Eva Forsgren; Joachim R. de Miranda

    2014-01-01

    The honey bee ectoparasitic mite, Varroa destructor, has a world-wide distribution and inflicts more damage than all other known apicultural diseases. However, Varroa-induced colony mortality is more accurately a result of secondary virus infections vectored by the mite. This means that honey bee resistance to Varroa may include resistance or tolerance to virus infections. The aim of this study was to see if this is the case for a unique population of mite-resistant (MR) European honey bees o...

  15. Plant virus infections control stomatal development

    Science.gov (United States)

    Murray, Rose R.; Emblow, Mark S. M.; Hetherington, Alistair M.; Foster, Gary D.

    2016-09-01

    Stomata are important regulators of carbon dioxide uptake and transpirational water loss. They also represent points of vulnerability as bacterial and fungal pathogens utilise this natural opening as an entry portal, and thus have an increasingly complex relationship. Unlike the situation with bacterial and fungal pathogens, we know very little about the role of stomata in viral infection. Here we report findings showing that viral infection influences stomatal development in two susceptible host systems (Nicotiana tabacum with TMV (Tobacco mosaic virus), and Arabidopsis thaliana with TVCV (Turnip vein-clearing virus)), but not in resistant host systems (Nicotiana glutinosa and Chenopodium quinoa with TMV). Virus infected plants had significantly lower stomatal indices in systemic leaves of susceptible systems; N. tabacum 9.8% reduction and A. thaliana 12.3% reduction, but not in the resistant hosts. Stomatal density in systemic leaves was also significantly reduced in virus infected A. thaliana by 19.6% but not in N. tabacum or the resistant systems. In addition, transpiration rate was significantly reduced in TMV infected N. tabacum.

  16. Endemic mycosis complicating human immunodeficiency virus infection.

    OpenAIRE

    Sarosi, G. A.; DAvies, S F

    1996-01-01

    Persons infected with the human immunodeficiency virus are prone to the development of many fungal diseases. Normal hosts with intact immunity usually recover from infection by these less-invasive fungi. In persons with compromised T-cell-mediated immunity, however, widespread dissemination from a pulmonary focus occurs. In this review, we discuss the epidemiology, clinical manifestations, diagnosis, and treatment of the three major North American mycoses, histoplasmosis, blastomycosis, and c...

  17. Activity of andrographolide against chikungunya virus infection

    OpenAIRE

    Phitchayapak Wintachai; Parveen Kaur; Regina Ching Hua Lee; Suwipa Ramphan; Atichat Kuadkitkan; Nitwara Wikan; Sukathida Ubol; Sittiruk Roytrakul; Justin Jang Hann Chu; Smith, Duncan R.

    2015-01-01

    Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus that has recently engendered large epidemics around the world. There is no specific antiviral for treatment of patients infected with CHIKV, and development of compounds with significant anti-CHIKV activity that can be further developed to a practical therapy is urgently required. Andrographolide is derived from Andrographis paniculata, a herb traditionally used to treat a number of conditions including infections. This stud...

  18. Prevention of respiratory syncytial virus infection

    OpenAIRE

    Samson, L

    2009-01-01

    Respiratory syncytial virus (RSV) infection is the leading cause of lower respiratory tract infection in young children, with significant numbers of premature infants and those with other risk factors requiring hospitalization in Canada each year. Palivizumab, an RSV-specific monoclonal antibody, can reduce the hospitalization rate and severity of illness for a small group of high-risk or premature infants during their first RSV season. The present statement reviews the published literature a...

  19. Adolescents and human immunodeficiency virus infection.

    Science.gov (United States)

    Anderson, J R

    1992-12-01

    As of March 31, 1992, individuals 13 to 19 years of age had been diagnosed with acquired immunodeficiency syndrome; over one third were diagnosed in the past 2 years alone. Because of the long incubation period from initial infection to acquired immunodeficiency syndrome diagnosis, the majority of young adults with acquired immunodeficiency syndrome were probably initially infected as adolescents. In 1991, 34% of adolescents with acquired immunodeficiency syndrome were female, and their predominant mode of transmission was heterosexual contact. Human immunodeficiency virus seroprevalence studies of adolescents show a male-to-female ratio approaching 1:1, with many human immunodeficiency virus-infected adolescent women identifying none of the standard risk. Factors such as sexual and drug experimentation, risk taking, and sense of invulnerability so characteristic of adolescence put adolescents at special risk for human immunodeficiency virus. There is no published information on if or how clinical manifestations of human immunodeficiency virus disease in adolescents might differ from those seen in adults. Medical care should be broad-based and should include access to clinical trials for new drug treatments. General knowledge levels about acquired immunodeficiency syndrome are high among US adolescents, but behavioral changes have lagged behind. All adolescents should be targeted for intensive education about human immunodeficiency virus along with interventions designed to enhance their general coping, communication, and decision-making skills. PMID:1450349

  20. Neopterin and human immunodeficiency virus infection

    DEFF Research Database (Denmark)

    Hofmann, B

    1993-01-01

    to predict the later development of AIDS. The increased neopterin concentrations show that the immune system is activated in HIV infection and demonstrate the presence of an interaction between the virus and the immune system. The most important future use of neopterin measurements may be in fast evaluation...

  1. Mental Status after West Nile Virus Infection

    OpenAIRE

    Haaland, Kathleen Y.; Sadek, Joseph; Pergam, Steven; Echevarria, Leonor A.; Davis, Larry E.; Goade, Diane; Harnar, Joanne; Nofchissey, Robert A.; Sewel, C. Mack; Ettestad, Paul

    2006-01-01

    Mental status after acute West Nile virus infection has not been examined objectively. We compared Telephone Interview for Cognitive Status scores of 116 patients with West Nile fever or West Nile neuroinvasive disease. Mental status was poorer and cognitive complaints more frequent with West Nile neuroinvasive disease (p = 0.005).

  2. Orf virus infection in sheep or goats.

    Science.gov (United States)

    Spyrou, V; Valiakos, G

    2015-12-14

    Orf virus, a member of the genus Parapoxvirus, is the causative agent of contagious ecthyma ('Orf'). It is a pathogen with worldwide distribution, causing significant financial losses in livestock production. The disease mainly affects sheep and goats, but various other ruminants and mammals have been reported to be infected as well. It is also a zoonotic disease, affecting mainly people who come in direct or indirect contact with infected animals (e.g. farmers, veterinarians). The disease is usually benign and self-limiting, although in many cases, especially in young animals, it can be persistent and even fatal. Production losses caused by Orf virus are believed to be underestimated, as it is not a notifiable disease. This review of literature presents all latest information regarding the virus; considerations regarding treatment and prevention will be also discussed. PMID:26315771

  3. Lethal Dengue Virus Infection: A Forensic Overview.

    Science.gov (United States)

    Byard, Roger W

    2016-06-01

    Dengue virus is a single-stranded RNA virus that is a member of the family Flaviviridae, genus Flavivirus. It is usually transmitted by the female Aedes aegypti mosquito. Dengue fever is a febrile illness caused by 1 of 4 serotypes of the virus, which may progress to dengue hemorrhagic fever or dengue shock syndrome. The mortality rate of untreated dengue shock syndrome is more than 20%. The reported incidence has increased 30-fold for the past 50 years with an estimated 50 to 100 million dengue infections globally each year, which includes 22,000 deaths. Because of this rapid increase in numbers, more cases will be seen in forensic mortuaries, with diagnostic problems arising from nonspecific or unusual manifestations. In this review, the clinicopathological features of dengue viral infection are evaluated. Adequate blood and tissue sampling at the time of autopsy is mandatory for successful microbiological identification and characterization. PMID:27093563

  4. Prevalence of occult hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    Maria Luisa Gutiérrez-García; Conrado M Fernandez-Rodriguez; Jose Luis Lledo-Navarro; Ingrid Buhigas-Garcia

    2011-01-01

    Occult hepatitis B virus (HBV) infection (OBI) is characterized by the persistence of HBV DNA in the liver tissue in individuals negative for the HBV surface antigen. The prevalence of OBI is quite variable depending on the level of endemic disease in different parts of the world,the different assays utilized in the studies, and the different populations studied. Many studies have been carried out on OBI prevalence in different areas of the world and categories of individuals. The studies show that OBI prevalence seems to be higher among subjects at high risk for HBV infection and with liver disease than among individuals at low risk of infection and without liver disease.

  5. Skin manifestations of West Nile virus infection.

    Science.gov (United States)

    Del Giudice, P; Schuffenecker, I; Zeller, H; Grelier, M; Vandenbos, F; Dellamonica, P; Counillon, E

    2005-01-01

    West Nile virus (WNV) infection is a potentially lethal arbovirus infection. Many notable outbreaks have occurred during the last few years throughout the world, including Europe and the USA. The severity of the disease is mainly related to the neurological complications. A maculopapular exanthema is reported as a clinical sign of the disease. Recently an outbreak of WNV infection occurred in southern France. Three patients out of 6 had a similar skin roseola-like eruption. The cluster of 3 cases of similar febrile roseola of unexplained cause during the same week led to the diagnosis of the first WNV human outbreak in France for 40 years. PMID:16286745

  6. Risk factors for hepatitis C virus infection

    Directory of Open Access Journals (Sweden)

    Mijailović Željko D.

    2003-01-01

    Full Text Available Introduction Hepatitis C viral infection represents a major health problem in the world. The estimated global incidence is about 3%, whereas the number of chronic hepatitis C virus (HCV carriers worldwide is estimated to be between 150-300 million people. Material and methods This retrospective analysis included 82 patients whose diagnosis of viral hepatitis C infection was based upon the following criteria: case history, physical examination, laboratory and abdominal ultrasound examination, histological examination of the liver, radiological examination, serological analysis and viral analysis. Descriptive statistics were used to describe general data on patients of the study group, risk factor analysis and follow-up results. Results The most prominent risk factor in our study group was intravenous use of drugs in 37 patients (37%, and blood transfusion in 13 patients (13%. Less important risk factors of viral hepatitis C infection included: promiscuity (8%, sexual contact with hepatitis C carriers (5%, surgical intervention (5%, haemodialysis (3%, intranasal use of cocaine (2%. Discussion Hepatitis C viral infection has become the illness of young and middle-aged population. This is due to the epidemic profile of this illness, due to intravenous use of drugs as the most prominent risk factor. Conclusion Due to the number of infected, numerous risk factors and complications of viral hepatitis C, hepatitis C virus has become the most prominent hepatotrophic virus.

  7. Hepatitis C virus infection and apoptosis

    Institute of Scientific and Technical Information of China (English)

    Richard Fischer; Thomas Baumert; Hubert E Blum

    2007-01-01

    Apoptosis is central for the control and elimination of viral infections. In chronic hepatitis C virus (HCV) infection,enhanced hepatocyte apoptosis and upregulation of the death inducing ligands CD95/Fas, TRAIL and TNFα occur.Nevertheless, HCV infection persists in the majority of patients. The impact of apoptosis in chronic HCV infection is not well understood. It may be harmful by triggering liver fibrosis, or essential in interferon (IFN)induced HCV elimination. For virtually all HCV proteins,pro- and anti-apoptotic effects have been described,especially for the core and NS5A protein. To date, it is not known which HCV protein affects apoptosis in vivo and whether the infectious virions act pro- or antiapoptotic. With the availability of an infectious tissue culture system, we now can address pathophysiologically relevant issues. This review focuses on the effect of HCV infection and different HCV proteins on apoptosis and of the corresponding signaling cascades.

  8. [Laboratory diagnosis of hepatitis C virus infection].

    Science.gov (United States)

    Huber, K R; Kittl, E; Sebesta, C; Bauer, K

    2000-01-01

    In Austria, the prevalence of hepatitis C virus infections is 0.7% (17). Exclusion of a putative infection as well as diagnosis and continuous monitoring of HCV-disease produce considerable costs for the health system. How many and which patients with HCV infection will acquire life-threatening complications is by far not clear. Also, the causes for viral persistence and liver-complications remain obscure. For certain, complex interactions of viral and immunological mechanisms will determine the individual outcome of the disease (1). These considerations pose decisive demands on clinical diagnostics for HCV infections to be dealt with in detail: methods for qualitative detection of an infection as well as for analysis of subtypes and for quantitative determination of viral copies; monitoring of therapy; estimation of the progress of the disease and/or efficacy of therapy. PMID:11205177

  9. Cells in Dengue Virus Infection In Vivo

    Directory of Open Access Journals (Sweden)

    Sansanee Noisakran

    2010-01-01

    Full Text Available Dengue has been recognized as one of the most important vector-borne emerging infectious diseases globally. Though dengue normally causes a self-limiting infection, some patients may develop a life-threatening illness, dengue hemorrhagic fever (DHF/dengue shock syndrome (DSS. The reason why DHF/DSS occurs in certain individuals is unclear. Studies in the endemic regions suggest that the preexisting antibodies are a risk factor for DHF/DSS. Viremia and thrombocytopenia are the key clinical features of dengue virus infection in patients. The amounts of virus circulating in patients are highly correlated with severe dengue disease, DHF/DSS. Also, the disturbance, mainly a transient depression, of hematological cells is a critical clinical finding in acute dengue patients. However, the cells responsible for the dengue viremia are unresolved in spite of the intensive efforts been made. Dengue virus appears to replicate and proliferate in many adapted cell lines, but these in vitro properties are extremely difficult to be reproduced in primary cells or in vivo. This paper summarizes reports on the permissive cells in vitro and in vivo and suggests a hematological cell lineage for dengue virus infection in vivo, with the hope that a new focus will shed light on further understanding of the complexities of dengue disease.

  10. Human immunodeficiency virus, herpes virus infections, and pulmonary vascular disease

    OpenAIRE

    Flores, Sonia C.; Almodovar, Sharilyn

    2013-01-01

    The following state-of-the-art seminar was delivered as part of the Aspen Lung Conference on Pulmonary Hypertension and Vascular Diseases held in Aspen, Colorado in June 2012. This paper will summarize the lecture and present results from a nonhuman primate model of infection with Simian (Human) Immunodeficiency Virus - nef chimeric virions as well as the idea that polymorphisms in the HIV-1 nef gene may be driving the immune response that results in exuberant inflammation and aberrant endoth...

  11. Zika virus infections in pregnancy: epidemics and case management

    OpenAIRE

    Fatih sahiner; Ali Korhan Sig; Umit Savasci; Kemal Tekin

    2016-01-01

    Zika virus is an RNA virus belonging to the Flaviviridae family, and is primarily transmitted by Aedes mosquitoes. Only a small number of cases had been described until 2007 when the first major Zika virus outbreak occurred on Yap Island, Micronesia. Approximately 80% of people infected with Zika virus do not exhibit any symptoms. Symptomatic infections are generally moderate and characterized by acute onset of fever, maculopapular rash, arthralgia, or conjunctivitis. The virus has recently a...

  12. Hepatitis C virus infection and the brain.

    Science.gov (United States)

    Weissenborn, Karin; Tryc, Anita B; Heeren, Meike; Worthmann, Hans; Pflugrad, Henning; Berding, Georg; Bokemeyer, Martin; Tillmann, Hans L; Goldbecker, Annemarie

    2009-03-01

    There is growing evidence that hepatitis C virus (HCV)-infection may affect the brain. About half of the HCV-infected patients complain of chronic fatigue irrespective of their stage of liver disease or virus replication rate. Even after successful antiviral therapy fatigue persists in about one third of the patients. Many patients, in addition, report of deficits in attention, concentration and memory, some also of depression. Psychometric testing revealed deficits in attention and verbal learning ability as characteristic for HCV-afflicted patients with normal liver function. Magnetic resonance spectroscopic studies showed alterations of the cerebral choline, N-acetyl-aspartate, and creatine content in the basal ganglia, white matter and frontal cortex, respectively. Recently, pathologic cerebral serotonin and dopamine transporter binding and regional alterations of the cerebral glucose utilisation compatible with alterations of the dopaminergic attentional system were observed. Several studies detected HCV in brain samples or cerebro-spinal fluid. Interestingly, viral sequences in the brain often differed from those in the liver, but were closely related to those found in lymphoid tissue. Therefore, the Trojan horse hypothesis emerged: HCV-infected mononuclear blood cells enter the brain, enabling the virus to reside within the brain (probably in microglia) and to infect brain cells, especially astrocytes. PMID:19130196

  13. Neutralizing antibodies in hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    Mirjam B Zeisel; Samira Fafi-Kremer; Isabel Fofana; Heidi Barth; Fran(c)oise Stoll-Keller; Michel Doffo(e)l; Thomas F Baumert

    2007-01-01

    Hepatitis C virus (HCV) is a major cause of hepatitis world-wide. The majority of infected individuals develop chronic hepatitis which can then progress to liver cirrhosis and hepatocellular carcinoma. Spontaneous viral clearance occurs in about 20%-30% of acutely infected individuals and results in resolution of infection without sequaelae. Both viral and host factors appear to play an important role for resolution of acute infection. A large body of evidence suggests that a strong, multispecific and long-lasting cellular immune response appears to be important for control of viral infection in acute hepatitis C. Due too the lack of convenient neutralization assays,the impact of neutralizing responses for control of viral infection had been less defined. In recent years, the development of robust tissue culture model systems for HCV entry and infection has finally allowed study of antibody-mediated neutralization and to gain further insights into viral targets of host neutralizing responses.In addition, detailed analysis of antibody-mediated neutralization in individual patients as well as cohorts with well defined viral isolates has enabled the study of neutralizing responses in the course of HCV infection and characterization of the impact of neutralizing antibodies for control of viral infection. This review will summarize recent progress in the understanding of the molecular mechanisms of antibody-mediated neutralization and its impact for HCV pathogenesis.(C) 2007 The WJG Press. All rights reserved.

  14. Zebrafish: modeling for herpes simplex virus infections.

    Science.gov (United States)

    Antoine, Thessicar Evadney; Jones, Kevin S; Dale, Rodney M; Shukla, Deepak; Tiwari, Vaibhav

    2014-02-01

    For many years, zebrafish have been the prototypical model for studies in developmental biology. In recent years, zebrafish has emerged as a powerful model system to study infectious diseases, including viral infections. Experiments conducted with herpes simplex virus type-1 in adult zebrafish or in embryo models are encouraging as they establish proof of concept with viral-host tropism and possible screening of antiviral compounds. In addition, the presence of human homologs of viral entry receptors in zebrafish such as 3-O sulfated heparan sulfate, nectins, and tumor necrosis factor receptor superfamily member 14-like receptor bring strong rationale for virologists to test their in vivo significance in viral entry in a zebrafish model and compare the structure-function basis of virus zebrafish receptor interaction for viral entry. On the other end, a zebrafish model is already being used for studying inflammation and angiogenesis, with or without genetic manipulations, and therefore can be exploited to study viral infection-associated pathologies. The major advantage with zebrafish is low cost, easy breeding and maintenance, rapid lifecycle, and a transparent nature, which allows visualizing dissemination of fluorescently labeled virus infection in real time either at a localized region or the whole body. Further, the availability of multiple transgenic lines that express fluorescently tagged immune cells for in vivo imaging of virus infected animals is extremely attractive. In addition, a fully developed immune system and potential for receptor-specific knockouts further advocate the use of zebrafish as a new tool to study viral infections. In this review, we focus on expanding the potential of zebrafish model system in understanding human infectious diseases and future benefits.

  15. Hepatitis C virus infection in the human immunodeficiency virus infected patient

    DEFF Research Database (Denmark)

    Clausen, Louise Nygaard; Lundbo, Lene Fogt; Benfield, Thomas

    2014-01-01

    Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) share the same transmission routes; therefore, coinfection is frequent. An estimated 5-10 million individuals alone in the western world are infected with both viruses. The majority of people acquire HCV by injection drug use and...... HIV-HCV coinfected individuals. Morbidity and mortality rates from chronic HCV infection will increase because the infection incidence peaked in the mid-1980s and because liver disease progresses slowly and is clinically silent to cirrhosis and end-stage-liver disease over a 15-20 year time period...... for 15%-20% of chronically infected individuals. HCV treatment has rapidly changed with the development of new direct-acting antiviral agents; therefore, cure rates have greatly improved because the new treatment regimens target different parts of the HCV life cycle. In this review, we focus...

  16. Human papilloma virus infection and psoriasis: Did human papilloma virus infection trigger psoriasis?

    OpenAIRE

    Jain, Sonia P.; Sachin Gulhane; Neha Pandey; Esha Bisne

    2015-01-01

    Psoriasis is an autoimmune chronic inflammatory skin disease known to be triggered by streptococcal and HIV infections. However, human papilloma virus infection (HPV) as a triggering factor for the development of psoriasis has not been reported yet. We, hereby report a case of plaque type with inverse psoriasis which probably could have been triggered by genital warts (HPV infection) and discuss the possible pathomechanisms for their coexistence and its management.

  17. [A NEW PANDEMIC: ZIKA VIRUS INFECTION].

    Science.gov (United States)

    Bourée, Patrice

    2016-06-01

    Zika virus is a flavivirus isolated in non human primates in 1647, then in humans 1954 (Uganda). It emerged on Micronesia (island af Yap) in 2007, then in French Polynesia in 2013-2014, in South America (mostly in Brazil and Colombia) in 2015 and in French West Indies in 2016. It is transmitted by the bite of Aedes mosquitoes. Zika virus infection is symptomatic in only 20% of cases and clinical presentation is associated with mild illness. But several neurological complications are reported (as Guillain-Barré syndrome: 48 cases in French Polynesia) and congenital malformations (microcephaly). Laboratory diagnosis is based on virus isolation by PCR. There is no specific treatment or vaccine available against the Zika virs. Prevention is based on measures of protection from mosquitoes bites. PMID:27538321

  18. [A NEW PANDEMIC: ZIKA VIRUS INFECTION].

    Science.gov (United States)

    Bourée, Patrice

    2016-06-01

    Zika virus is a flavivirus isolated in non human primates in 1647, then in humans 1954 (Uganda). It emerged on Micronesia (island af Yap) in 2007, then in French Polynesia in 2013-2014, in South America (mostly in Brazil and Colombia) in 2015 and in French West Indies in 2016. It is transmitted by the bite of Aedes mosquitoes. Zika virus infection is symptomatic in only 20% of cases and clinical presentation is associated with mild illness. But several neurological complications are reported (as Guillain-Barré syndrome: 48 cases in French Polynesia) and congenital malformations (microcephaly). Laboratory diagnosis is based on virus isolation by PCR. There is no specific treatment or vaccine available against the Zika virs. Prevention is based on measures of protection from mosquitoes bites.

  19. Epidemiology of hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    Miriam J Alter

    2007-01-01

    Globally, hepatitis C virus (HCV) has infected an estimated 130 million people, most of whom are chronically infected. HCV-infected people serve as a reservoir for transmission to others and are at risk for developing chronic liver disease, cirrhosis, and primary hepatocellular carcinoma (HCC). It has been estimated that HCV accounts for 27% of cirrhosis and 25% of HCC worldwide. HCV infection has likely been endemic in many populations for centuries. However, the wave of increased HCV-related morbidity and mortality that we are now facing is the result of an unprecedented increase in the spread of HCV during the 20th century.Two 20th century events appear to be responsible for this increase; the widespread availability of injectable therapies and the illicit use of injectable drugs.

  20. Diagnostic challenges of hepatitis C virus infections.

    Science.gov (United States)

    Huber, K; Sebesta, C; Worofka, B; Kittl, E; Hofmann, J; Klar, S; Hinterberger, W; Bauer, K

    1998-01-01

    In less than 10 years, tremendous progress has been made in our understanding of the biology of hepatitis C virus. Since it was defined as the causal agent of most hepatitis non-A, non-B infections in 1989, clinical laboratories now have access to powerful new techniques for the diagnosis of infection and control of therapy. Identification of the specific virus strain in the patients as well as measurement of the individual viral load and the prediction of a possible therapeutic success have become routine procedures. This effort is warranted because the treatment options are still limited, with alpha-interferon being the only approved drug. No new treatment regimens have emerged yet from the wealth of data from subtyping and quantitating. PMID:15094859

  1. Animal Models of Varicella Zoster Virus Infection

    Directory of Open Access Journals (Sweden)

    Ilhem Messaoudi

    2013-05-01

    Full Text Available Primary infection with varicella zoster virus (VZV results in varicella (chickenpox followed by the establishment of latency in sensory ganglia. Declining T cell immunity due to aging or immune suppressive treatments can lead to VZV reactivation and the development of herpes zoster (HZ, shingles. HZ is often associated with significant morbidity and occasionally mortality in elderly and immune compromised patients. There are currently two FDA-approved vaccines for the prevention of VZV: Varivax® (for varicella and Zostavax® (for HZ. Both vaccines contain the live-attenuated Oka strain of VZV. Although highly immunogenic, a two-dose regimen is required to achieve a 99% seroconversion rate. Zostavax vaccination reduces the incidence of HZ by 51% within a 3-year period, but a significant reduction in vaccine-induced immunity is observed within the first year after vaccination. Developing more efficacious vaccines and therapeutics requires a better understanding of the host response to VZV. These studies have been hampered by the scarcity of animal models that recapitulate all aspects of VZV infections in humans. In this review, we describe different animal models of VZV infection as well as an alternative animal model that leverages the infection of Old World macaques with the highly related simian varicella virus (SVV and discuss their contributions to our understanding of pathogenesis and immunity during VZV infection.

  2. Perinatal Chicken Pox (Varicella Zoster Virus) Infection

    OpenAIRE

    Ali Annagur; Ayhan Tastekin; Pervin Gunaslan; Oguzhan Demirel; Ahmet Hakan Dikener

    2013-01-01

    Chickenpox is due to infection with the varicella zoster virus (VZV), a human alphaherpervirus found worldwide. Classically, the cinical disease is a febrile illness with a pruritic vesicular rash. Maternal chickenpox between 5 days before delivery to 2 days after delivery (perinatal varicella) can cause severe and even fatal illness in the newborn. A 7-day old girl baby presented on day 4 of postnatal with the complaints of widespread vesicular rash and non-suckling. Mother of the baby also ...

  3. Mechanisms of Zika Virus Infection and Neuropathogenesis.

    Science.gov (United States)

    Olagnier, David; Muscolini, Michela; Coyne, Carolyn B; Diamond, Michael S; Hiscott, John

    2016-08-01

    A spotlight has been focused on the mosquito-borne Zika virus (ZIKV) because of its epidemic outbreak in Brazil and Latin America, as well as the severe neurological manifestations of microcephaly and Guillain-Barré syndrome associated with infection. In this review, we discuss the recent literature on ZIKV-host interactions, including new mechanistic insight concerning the basis of ZIKV-induced neuropathogenesis.

  4. Mechanisms of Zika Virus Infection and Neuropathogenesis.

    Science.gov (United States)

    Olagnier, David; Muscolini, Michela; Coyne, Carolyn B; Diamond, Michael S; Hiscott, John

    2016-08-01

    A spotlight has been focused on the mosquito-borne Zika virus (ZIKV) because of its epidemic outbreak in Brazil and Latin America, as well as the severe neurological manifestations of microcephaly and Guillain-Barré syndrome associated with infection. In this review, we discuss the recent literature on ZIKV-host interactions, including new mechanistic insight concerning the basis of ZIKV-induced neuropathogenesis. PMID:27348136

  5. Autoimmune Diseases Co-Existing with Hepatitis C Virus Infection

    Directory of Open Access Journals (Sweden)

    Zohreh Jadali

    2010-12-01

    Full Text Available Autoimmunity and viral infections are closely associated fields, and viruses have been proposed as a likely aetiological, contributory or triggering factors of systemic autoimmune diseases. Hepatitis C virus seems to be the virus usually associated with the appearance of autoimmune diseases, and the relationship between chronic hepatitis C virus infection and some autoimmune disease has been studied. For some of these disorders their association with hepatitis C virus infection is well recognized while for others it remains probable or weak. Examples of autoimmune phenomena observed in chronic hepatitis C virus infection include rheumatoid arthritis, thyroid disease, cryoglobulinaemia, immune thrombocytopenic purpura, systemic lupus erythematosus and sjogren syndrome. To date, the etiological role and the pathogenetic involvement of the hepatitis C infection remains unknown.The aim of this study is to assess the presence of different autoimmune manifestations of hepatitis C virus infection reported in literature.

  6. Vaccinia virus infections in martial arts gym, Maryland, USA, 2008.

    Science.gov (United States)

    Hughes, Christine M; Blythe, David; Li, Yu; Reddy, Ramani; Jordan, Carol; Edwards, Cindy; Adams, Celia; Conners, Holly; Rasa, Catherine; Wilby, Sue; Russell, Jamaal; Russo, Kelly S; Somsel, Patricia; Wiedbrauk, Danny L; Dougherty, Cindy; Allen, Christopher; Frace, Mike; Emerson, Ginny; Olson, Victoria A; Smith, Scott K; Braden, Zachary; Abel, Jason; Davidson, Whitni; Reynolds, Mary; Damon, Inger K

    2011-04-01

    Vaccinia virus is an orthopoxvirus used in the live vaccine against smallpox. Vaccinia virus infections can be transmissible and can cause severe complications in those with weakened immune systems. We report on a cluster of 4 cases of vaccinia virus infection in Maryland, USA, likely acquired at a martial arts gym.

  7. Significance of blood analysis in hemophiliacs co-infected with human immunodeficiency virus and hepatitis viruses

    Institute of Scientific and Technical Information of China (English)

    Fang Shen; Qin Huang; Hong-Qing Sun; Reena Ghildyal

    2007-01-01

    AIM:To study the effect of hepatitis virus infection on cirrhosis and liver function markers in HIV-infected hemophiliacs.METHODS:We have analyzed the immunological,liver function and cirrhosis markers in a cohort of hemophiliacs co-infected with human immunodeficiency virus (HIV) and hepatitis viruses.RESULTS:There was no difference in immunological markers among co-infected patients and patients infected with HIV only and those co-infected with one or more hepatitis virus. Although liver function and cirrhosis markers remained within a normal range,there was a worsening trend in all patients co-infected with hepatitis virus C (HCV),which was further exacerbated in the presence of additional infection with hepatitis virus B (HBV).CONCLUSION:Co-infection with HIV,HBV and HCV leads to worsening of hyaluronic acid and liver function markers. Increases in serum hyaluronic acid may be suggestive of a predisposition to liver diseases.

  8. Activity of andrographolide against chikungunya virus infection.

    Science.gov (United States)

    Wintachai, Phitchayapak; Kaur, Parveen; Lee, Regina Ching Hua; Ramphan, Suwipa; Kuadkitkan, Atichat; Wikan, Nitwara; Ubol, Sukathida; Roytrakul, Sittiruk; Chu, Justin Jang Hann; Smith, Duncan R

    2015-01-01

    Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus that has recently engendered large epidemics around the world. There is no specific antiviral for treatment of patients infected with CHIKV, and development of compounds with significant anti-CHIKV activity that can be further developed to a practical therapy is urgently required. Andrographolide is derived from Andrographis paniculata, a herb traditionally used to treat a number of conditions including infections. This study sought to determine the potential of andrographolide as an inhibitor of CHIKV infection. Andrographolide showed good inhibition of CHIKV infection and reduced virus production by approximately 3log10 with a 50% effective concentration (EC50) of 77 μM without cytotoxicity. Time-of-addition and RNA transfection studies showed that andrographolide affected CHIKV replication and the activity of andrographolide was shown to be cell type independent. This study suggests that andrographolide has the potential to be developed further as an anti-CHIKV therapeutic agent. PMID:26384169

  9. Viral protein synthesis in cowpea mosaic virus infected protoplasts

    International Nuclear Information System (INIS)

    Some aspects of cowpea mosaic virus (CPMV) multiplication in cowpea mesophyll protoplasts were studied. The detection and characterization of proteins whose synthesis is induced or is stimulated upon virus infection was performed with the aid of radioactive labelling. (Auth.)

  10. First Imported Case of Zika Virus Infection into Korea

    OpenAIRE

    Jang, Hee-Chang; Park, Wan Beom; Kim, Uh Jin; Chun, June Young; Choi, Su-jin; Choe, Pyoeng Gyun; Jung, Sook-In; Jee, Youngmee; Kim, Nam Joong; Choi, Eun Hwa; Oh, Myoung-Don

    2016-01-01

    Since Zika virus has been spreading rapidly in the Americas from 2015, the outbreak of Zika virus infection becomes a global health emergency because it can cause neurological complications and adverse fetal outcome including microcephaly. Here, we report clinical manifestations and virus isolation findings from a case of Zika virus infection imported from Brazil. The patient, 43-year-old Korean man, developed fever, myalgia, eyeball pain, and maculopapular rash, but not neurological manifest...

  11. Genetic Strategy to Prevent Influenza Virus Infections in Animals

    OpenAIRE

    Chen, Jianzhu; Chen, Steve C.-Y.; Stern, Patrick; Scott, Benjamin B; Lois, Carlos

    2008-01-01

    The natural reservoirs of influenza viruses are aquatic birds. After adaptation, avian viruses can acquire the ability to infect humans and cause severe disease. Because domestic poultry serves as a key link between the natural reservoir of influenza viruses and epidemics and pandemics in human populations, an effective measure to control influenza would be to eliminate or reduce influenza virus infection in domestic poultry. The development and distribution of influenza-resistant poultry rep...

  12. Bilateral optic neuritis in acute human immunodeficiency virus infection

    DEFF Research Database (Denmark)

    Larsen, M; Toft, P.B.; Bernhard, P;

    1998-01-01

    PURPOSE: To report a case of acute viral disease accompanied by bilateral optic neuritis with substantial paraclinical evidence that human immunodeficiency virus was the causative agent. METHODS: Clinical and paraclinical examination. Magnetic resonance imaging. RESULTS: Virus and antibody titers...... as well as reverse lymphocytosis were consistent with acute infection by the human immunodeficiency virus-1. CONCLUSIONS: Human immunodeficiency virus infection should be considered in the differential diagnosis of acute optic neuritis...

  13. Comparison of association of diabetes mellitus in hepatitis C virus infection and hepatitis B virus infection

    International Nuclear Information System (INIS)

    Background: While patients with liver disease are known to have a higher prevalence of glucose intolerance, preliminary studies suggest that hepatitis C virus (HCV) infection may be an additional risk factor for the development of diabetes mellitus (DM). Objective: The presented study was aimed to study and determine a relationship between the relative proportions of Diabetes Mellitus in patients suffering from HCV infection. Study Design: This cross sectional study. Study Settings: Patients were registered from outdoor as well as indoor departments of different teaching hospitals (Services hospital Lahore and medical departments in Jinnah hospital, Mayo hospital, Sir Ganga Ram hospital) in Lahore, Pakistan. Methods: This cross sectional study was comprised of age and sex matched 258 patients of viral hepatitis B infection and viral hepatitis C infection, conducted at Hepatitis Clinic Services Hospital, affiliated with Post Graduate Medical Institute, Lahore. Diagnosis of HBV was made with evidence of hepatitis B surface antigen, HCV infection was diagnosed if patient was sero positive for anti HCV (ELISA methods) and HCV - RNA (By PCR). Diabetes Mellitus was diagnosed after fulfilling the American Diabetic Association Criteria, from November, 2000 to September, 2002. Results: A total of 318 patients were registered, out of which 258 cases fulfilled the inclusion criteria, 164 hepatitis C infected and 94 hepatitis B infected cases, 16.46% hepatitis C infected cases were diagnosed as diabetics while 4.25% hepatitis B infected cases were diagnosed as diabetics. Conclusion: This study concludes that there is high Association and relationship of Diabetes Mellitus with Hepatitis C virus infection as compared with Hepatitis B virus infection. (author)

  14. Imunocompetent Mice Model for Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Denise Gonçalves

    2012-01-01

    Full Text Available Dengue fever is a noncontagious infectious disease caused by dengue virus (DENV. DENV belongs to the family Flaviviridae, genus Flavivirus, and is classified into four antigenically distinct serotypes: DENV-1, DENV-2, DENV-3, and DENV-4. The number of nations and people affected has increased steadily and today is considered the most widely spread arbovirus (arthropod-borne viral disease in the world. The absence of an appropriate animal model for studying the disease has hindered the understanding of dengue pathogenesis. In our study, we have found that immunocompetent C57BL/6 mice infected intraperitoneally with DENV-1 presented some signs of dengue disease such as thrombocytopenia, spleen hemorrhage, liver damage, and increase in production of IFNγ and TNFα cytokines. Moreover, the animals became viremic and the virus was detected in several organs by real-time RT-PCR. Thus, this animal model could be used to study mechanism of dengue virus infection, to test antiviral drugs, as well as to evaluate candidate vaccines.

  15. Chaperones in hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    The hepatitis C virus (HCV) infects approximately 3% ofthe world population or more than 185 million peopleworldwide. Each year, an estimated 350000-500000deaths occur worldwide due to HCV-associated diseasesincluding cirrhosis and hepatocellular carcinoma. HCV isthe most common indication for liver transplantation inpatients with cirrhosis worldwide. HCV is an envelopedRNA virus classified in the genus Hepacivirus in theFlaviviridae family. The HCV viral life cycle in a cellcan be divided into six phases (1) binding and internalization;(2) cytoplasmic release and uncoating; (3)viral polyprotein translation and processing; (4) RNAgenome replication; (5) encapsidation (packaging) andassembly; and (6) virus morphogenesis (maturation)and secretion. Many host factors are involved in theHCV life cycle. Chaperones are an important group ofhost cytoprotective molecules that coordinate numerouscellular processes including protein folding, multimericprotein assembly, protein trafficking, and proteindegradation. All phases of the viral life cycle requirechaperone activity and the interaction of viral proteinswith chaperones. This review will present our currentknowledge and understanding of the role of chaperonesin the HCV life cycle. Analysis of chaperones in HCVinfection will provide further insights into viral/hostinteractions and potential therapeutic targets for bothHCV and other viruses.

  16. Ebola virus (EBOV) infection: Therapeutic strategies.

    Science.gov (United States)

    De Clercq, Erik

    2015-01-01

    Within less than a year after its epidemic started (in December 2013) in Guinea, Ebola virus (EBOV), a member of the filoviridae, has spread over a number of West-African countries (Guinea, Sierra Leone and Liberia) and gained allures that have been unprecedented except by human immunodeficiency virus (HIV). Although EBOV is highly contagious and transmitted by direct contact with body fluids, it could be counteracted by the adequate chemoprophylactic and -therapeutic interventions: vaccines, antibodies, siRNAs (small interfering RNAs), interferons and chemical substances, i.e. neplanocin A derivatives (i.e. 3-deazaneplanocin A), BCX4430, favipiravir (T-705), endoplasmic reticulum (ER) α-glucosidase inhibitors and a variety of compounds that have been found to inhibit EBOV infection blocking viral entry or by a mode of action that still has to be resolved. Much has to be learned from the mechanism of action of the compounds active against VSV (vesicular stomatitis virus), a virus belonging to the rhabdoviridae, that in its mode of replication could be exemplary for the replication of filoviridae. PMID:25481298

  17. Fatal canine distemper virus infection of giant pandas in China

    OpenAIRE

    Na Feng; Yicong Yu; Tiecheng Wang; Peter Wilker; Jianzhong Wang; Yuanguo Li; Zhe Sun; Yuwei Gao; Xianzhu Xia

    2016-01-01

    We report an outbreak of canine distemper virus (CDV) infection among endangered giant pandas (Ailuropoda melanoleuca). Five of six CDV infected giant pandas died. The surviving giant panda was previously vaccinated against CDV. Genomic sequencing of CDV isolated from one of the infected pandas (giant panda/SX/2014) suggests it belongs to the Asia-1 cluster. The hemagglutinin protein of the isolated virus and virus sequenced from lung samples originating from deceased giant pandas all possess...

  18. H5N6 influenza virus infection, the newest influenza

    Institute of Scientific and Technical Information of China (English)

    Beuy; Joob; Wiwanitkit; Viroj

    2015-01-01

    The most recent new emerging infection is the H5N6 inl uenza virus infection. This infection has just been reported from China in early May 2014. The disease is believed to be a cross species infection. All indexed cases are from China. Of interest, the H5N6 inl uenza virus is the primary virus for avian. The avian H5N6 inl uenza virus in avian population is a low virulent strain. However, the clinical manifestation in human seems severe. In this mini-review, the authors summarize and discuss on this new emerging inl uenza.

  19. Hepatitis B virus and hepatitis C virus infection inhealthcare workers

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Approximately 3 million healthcare workers per yearreceive an injury with an occupational instrument, witharound 2000000 exposures to hepatitis B virus (HBV)and 1000000 to hepatitis C virus (HCV). Although aneffective HBV vaccine has been available since theearly eighties, and despite the worldwide applicationof universal vaccination programs started in the earlynineties, HBV still remains a prominent agent of morbidityand mortality. There is no vaccine to limit thediffusion of HCV infection, which progresses to chronicityin the majority of cases and is a major cause of morbidityand mortality worldwide due to a chronic liverdisease. Healthcare workers are frequently exposed by amucosal-cutaneous or percutaneous route to accidentalcontact with human blood and other potentially infectiousbiological materials while carrying out their occupationalduties. Mucosal-cutaneous exposure occurswhen the biological material of a potentially infectedpatient accidentally comes in contact with the mucousmembranes of the eyes or mouth or with the skin of ahealthcare worker. Percutaneous exposure occurs whenan operator accidentally injures himself with a sharpcontaminated object, like a needle, blade or other sharpmedical instrument. About 75% of the total occupationalexposure is percutaneous and 25% mucosal-cutaneous,the risk of infecting a healthcare worker being higherin percutaneous than in mucosal-cutaneous exposure.All healthcare workers should be considered for HBVvaccination and should meticulously apply the universalprophylactic measures to prevent exposure to HBV andHCV.

  20. Animal Models of Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Eva Harris

    2012-01-01

    Full Text Available The development of animal models of dengue virus (DENV infection and disease has been challenging, as epidemic DENV does not naturally infect non-human species. Non-human primates (NHPs can sustain viral replication in relevant cell types and develop a robust immune response, but they do not develop overt disease. In contrast, certain immunodeficient mouse models infected with mouse-adapted DENV strains show signs of severe disease similar to the ‘vascular-leak’ syndrome seen in severe dengue in humans. Humanized mouse models can sustain DENV replication and show some signs of disease, but further development is needed to validate the immune response. Classically, immunocompetent mice infected with DENV do not manifest disease or else develop paralysis when inoculated intracranially; however, a new model using high doses of DENV has recently been shown to develop hemorrhagic signs after infection. Overall, each model has its advantages and disadvantages and is differentially suited for studies of dengue pathogenesis and immunopathogenesis and/or pre-clinical testing of antiviral drugs and vaccines.

  1. Sofosbuvir treatment and hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Hepatitis C virus (HCV) infection is a serious problemworldwide. The use of interferon-based therapy hasmade HCV eradication challenging. The recent appearanceof direct-acting antiviral agents (DAAs) haschanged HCV therapy. Combining the use of DAAs withpeginterferon and ribavirin has improved treatmentefficacy. Furthermore, the combination of different orallyadministered DAAs has enabled interferon-free therapywith much higher efficacy and safety. In particular,sofosbuvir, a nucleotide-based NS5B inhibitor, preventsHCV RNA synthesis by acting as a "chain terminator".Treatment with sofosbuvir has attained an extremelyhigh rate of sustained virologic response. The currentreview summarizes the efficacy and safety of sofosbuvirtherapy.

  2. The ecology of viruses that infect eukaryotic algae.

    Science.gov (United States)

    Short, Steven M

    2012-09-01

    Because viruses of eukaryotic algae are incredibly diverse, sweeping generalizations about their ecology are rare. These obligate parasites infect a range of algae and their diversity can be illustrated by considering that isolates range from small particles with ssRNA genomes to much larger particles with 560 kb dsDNA genomes. Molecular research has also provided clues about the extent of their diversity especially considering that genetic signatures of algal viruses in the environment rarely match cultivated viruses. One general concept in algal virus ecology that has emerged is that algal viruses are very host specific and most infect only certain strains of their hosts; with the exception of viruses of brown algae, evidence for interspecies infectivity is lacking. Although some host-virus systems behave with boom-bust oscillations, complex patterns of intraspecies infectivity can lead to host-virus coexistence obfuscating the role of viruses in host population dynamics. Within the framework of population dynamics, host density dependence is an important phenomenon that influences virus abundances in nature. Variable burst sizes of different viruses also influence their abundances and permit speculations about different life strategies, but as exceptions are common in algal virus ecology, life strategy generalizations may not be broadly applicable. Gaps in knowledge of virus seasonality and persistence are beginning to close and investigations of environmental reservoirs and virus resilience may answer questions about virus inter-annual recurrences. Studies of algal mortality have shown that viruses are often important agents of mortality reinforcing notions about their ecological relevance, while observations of the surprising ways viruses interact with their hosts highlight the immaturity of our understanding. Considering that just two decades ago algal viruses were hardly acknowledged, recent progress affords the optimistic perspective that future studies

  3. Hepatitis B virus infection in Indonesia.

    Science.gov (United States)

    Yano, Yoshihiko; Utsumi, Takako; Lusida, Maria Inge; Hayashi, Yoshitake

    2015-10-14

    Approximately 240 million people are chronically infected with hepatitis B virus (HBV), 75% of whom reside in Asia. Approximately 600000 of infected patients die each year due to HBV-related diseases or hepatocellular carcinoma (HCC). The endemicity of hepatitis surface antigen in Indonesia is intermediate to high with a geographical difference. The risk of HBV infection is high in hemodialysis (HD) patients, men having sex with men, and health care workers. Occult HBV infection has been detected in various groups such as blood donors, HD patients, and HIV-infected individuals and children. The most common HBV subgenotype in Indonesia is B3 followed by C1. Various novel subgenotypes of HBV have been identified throughout Indonesia, with the novel HBV subgenotypes C6-C16 and D6 being successfully isolated. Although a number of HBV subgenotypes have been discovered in Indonesia, genotype-related pathogenicity has not yet been elucidated in detail. Therefore, genotype-related differences in the prognosis of liver disease and their effects on treatments need to be determined. A previous study conducted in Indonesia revealed that hepatic steatosis was associated with disease progression. Pre-S2 mutations and mutations at C1638T and T1753V in HBV/B3 have been associated with advanced liver diseases including HCC. However, drug resistance to lamivudine, which is prominent in Indonesia, remains obscure. Although the number of studies on HBV in Indonesia has been increasing, adequate databases on HBV infection are limited. We herein provided an overview of the epidemiology and clinical characteristics of HBV infection in Indonesia.

  4. Respiratory syncytial virus infection in elderly adults.

    Science.gov (United States)

    Falsey, Ann R; Walsh, Edward E

    2005-01-01

    Respiratory syncytial virus (RSV) infection is now recognised as a significant problem in elderly adults. Epidemiological evidence indicates the impact of RSV in older adults may be similar to non-pandemic influenza, both in the community and in long-term care facilities. Attack rates in nursing homes are approximately 5-10% per year with significant rates of pneumonia (10-20%) and death (2-5%). Estimates using US health care databases and viral surveillance results over a 9-year period indicate that RSV infection causes approximately 10,000 all-cause deaths annually among persons >64 years of age. In contrast, influenza A accounted for approximately 37,000 yearly deaths in the same age group. The clinical features of RSV infection may be difficult to distinguish from those of influenza but include nasal congestion, cough, wheezing and low-grade fever. Older persons with underlying heart and lung disease and immunocompromised patients are at highest risk for RSV infection-related pneumonia and death. Diagnosis of RSV infection in adults is difficult because viral culture and antigen detection are insensitive, presumably because of low viral titres. The combination of serology and reverse transcriptase polymerase chain reaction assay offers the best sensitivity and specificity for the diagnosis of RSV but unfortunately these techniques are not widely available; consequently, most adult RSV disease goes unrecognised. Although treatment of RSV infection in the elderly is largely supportive, early therapy with ribavirin and intravenous gamma-globulin improves survival in immunocompromised persons. An effective RSV vaccine has not yet been developed. Therefore, prevention of RSV is limited to standard infection control practices, such as hand washing and the use of gowns and gloves. PMID:16038573

  5. Zika virus infections in pregnancy: epidemics and case management

    Directory of Open Access Journals (Sweden)

    Fatih sahiner

    2016-03-01

    Full Text Available Zika virus is an RNA virus belonging to the Flaviviridae family, and is primarily transmitted by Aedes mosquitoes. Only a small number of cases had been described until 2007 when the first major Zika virus outbreak occurred on Yap Island, Micronesia. Approximately 80% of people infected with Zika virus do not exhibit any symptoms. Symptomatic infections are generally moderate and characterized by acute onset of fever, maculopapular rash, arthralgia, or conjunctivitis. The virus has recently attracted a broad interest due to the emerging cases of microcephaly that are possibly associated with mothers infected by the Zika virus during pregnancy, and the regional increases in the incidence of Guillain-Barre syndrome during the epidemic periods. Although the relationship between Zika virus infection and these abnormalities is not obviously understood yet, Zika virus testing is recommended for infants with microcephaly or intracranial calcifications whose mothers were potentially infected with the Zika virus during pregnancy. Every day, new reports are being published about the outbreaks associated with this virus; nevertheless, no new cases of this virus have been reported in Turkey. Despite this, we cannot currently exclude the possibility of the encounter with the virus because of the presence of Aedes mosquitoes, which are responsible for the spread of the virus, are prevalent in Turkey, and an increasing number of travel-related cases are being reported from different countries. In the light of the current knowledge on this virus, this review aims to discuss the course of Zika virus infections in detail, especially congenital infection, and presenting current information about the case management and preventive measures. [Cukurova Med J 2016; 41(1.000: 143-151

  6. Encephalomyocarditis virus infection in an Italian zoo.

    Science.gov (United States)

    Canelli, Elena; Luppi, Andrea; Lavazza, Antonio; Lelli, Davide; Sozzi, Enrica; Martin, Ana M Moreno; Gelmetti, Daniela; Pascotto, Ernesto; Sandri, Camillo; Magnone, William; Cordioli, Paolo

    2010-01-01

    A fatal Encephalomyocarditis virus (EMCV) infection epidemic involving fifteen primates occurred between October 2006 and February 2007 at the Natura Viva Zoo. This large open-field zoo park located near Lake Garda in Northern Italy hosts one thousand animals belonging to one hundred and fifty different species, including various lemur species. This lemur collection is the most relevant and rich in Italy. A second outbreak between September and November 2008 involved three lemurs. In all cases, the clinical signs were sudden deaths generally without any evident symptoms or only with mild unspecific clinical signs. Gross pathologic changes were characterized by myocarditis (diffuse or focal pallor of the myocardium), pulmonary congestion, emphysema, oedema and thoracic fluid. The EMCV was isolated and recognized as the causative agent of both outbreaks. The first outbreak in particular was associated with a rodent plague, confirming that rats are an important risk factor for the occurrence of the EMCV infection.

  7. Encephalomyocarditis virus infection in an Italian zoo

    Directory of Open Access Journals (Sweden)

    Pascotto Ernesto

    2010-03-01

    Full Text Available Abstract A fatal Encephalomyocarditis virus (EMCV infection epidemic involving fifteen primates occurred between October 2006 and February 2007 at the Natura Viva Zoo. This large open-field zoo park located near Lake Garda in Northern Italy hosts one thousand animals belonging to one hundred and fifty different species, including various lemur species. This lemur collection is the most relevant and rich in Italy. A second outbreak between September and November 2008 involved three lemurs. In all cases, the clinical signs were sudden deaths generally without any evident symptoms or only with mild unspecific clinical signs. Gross pathologic changes were characterized by myocarditis (diffuse or focal pallor of the myocardium, pulmonary congestion, emphysema, oedema and thoracic fluid. The EMCV was isolated and recognized as the causative agent of both outbreaks. The first outbreak in particular was associated with a rodent plague, confirming that rats are an important risk factor for the occurrence of the EMCV infection.

  8. Perinatal Chicken Pox (Varicella Zoster Virus Infection

    Directory of Open Access Journals (Sweden)

    Ali Annagur

    2013-04-01

    Full Text Available Chickenpox is due to infection with the varicella zoster virus (VZV, a human alphaherpervirus found worldwide. Classically, the cinical disease is a febrile illness with a pruritic vesicular rash. Maternal chickenpox between 5 days before delivery to 2 days after delivery (perinatal varicella can cause severe and even fatal illness in the newborn. A 7-day old girl baby presented on day 4 of postnatal with the complaints of widespread vesicular rash and non-suckling. Mother of the baby also had a similar eruption four day prior to delivery, which was clinically characteristic of varicella. Considering history and clinical presentation, a diagnosis of perinatal chickenpox was considered and the baby was treated with acyclovir which she responded and recovered. Herein, the clinical feasures and treatment of chickenpox infection in the perinatal period have been emphasized with this case report. [Cukurova Med J 2013; 38(2.000: 311-314

  9. Zika Virus Infects Human Placental Macrophages.

    Science.gov (United States)

    Quicke, Kendra M; Bowen, James R; Johnson, Erica L; McDonald, Circe E; Ma, Huailiang; O'Neal, Justin T; Rajakumar, Augustine; Wrammert, Jens; Rimawi, Bassam H; Pulendran, Bali; Schinazi, Raymond F; Chakraborty, Rana; Suthar, Mehul S

    2016-07-13

    The recent Zika virus (ZIKV) outbreak in Brazil has been directly linked to increased cases of microcephaly in newborns. Current evidence indicates that ZIKV is transmitted vertically from mother to fetus. However, the mechanism of intrauterine transmission and the cell types involved remain unknown. We demonstrate that the contemporary ZIKV strain PRVABC59 (PR 2015) infects and replicates in primary human placental macrophages, called Hofbauer cells, and to a lesser extent in cytotrophoblasts, isolated from villous tissue of full-term placentae. Viral replication coincides with induction of type I interferon (IFN), pro-inflammatory cytokines, and antiviral gene expression, but with minimal cell death. Our results suggest a mechanism for intrauterine transmission in which ZIKV gains access to the fetal compartment by directly infecting placental cells and disrupting the placental barrier. PMID:27247001

  10. Honey Bee Infecting Lake Sinai Viruses.

    Science.gov (United States)

    Daughenbaugh, Katie F; Martin, Madison; Brutscher, Laura M; Cavigli, Ian; Garcia, Emma; Lavin, Matt; Flenniken, Michelle L

    2015-06-01

    Honey bees are critical pollinators of important agricultural crops. Recently, high annual losses of honey bee colonies have prompted further investigation of honey bee infecting viruses. To better characterize the recently discovered and very prevalent Lake Sinai virus (LSV) group, we sequenced currently circulating LSVs, performed phylogenetic analysis, and obtained images of LSV2. Sequence analysis resulted in extension of the LSV1 and LSV2 genomes, the first detection of LSV4 in the US, and the discovery of LSV6 and LSV7. We detected LSV1 and LSV2 in the Varroa destructor mite, and determined that a large proportion of LSV2 is found in the honey bee gut, suggesting that vector-mediated, food-associated, and/or fecal-oral routes may be important for LSV dissemination. Pathogen-specific quantitative PCR data, obtained from samples collected during a small-scale monitoring project, revealed that LSV2, LSV1, Black queen cell virus (BQCV), and Nosema ceranae were more abundant in weak colonies than strong colonies within this sample cohort. Together, these results enhance our current understanding of LSVs and illustrate the importance of future studies aimed at investigating the role of LSVs and other pathogens on honey bee health at both the individual and colony levels. PMID:26110586

  11. Honey Bee Infecting Lake Sinai Viruses

    Directory of Open Access Journals (Sweden)

    Katie F. Daughenbaugh

    2015-06-01

    Full Text Available Honey bees are critical pollinators of important agricultural crops. Recently, high annual losses of honey bee colonies have prompted further investigation of honey bee infecting viruses. To better characterize the recently discovered and very prevalent Lake Sinai virus (LSV group, we sequenced currently circulating LSVs, performed phylogenetic analysis, and obtained images of LSV2. Sequence analysis resulted in extension of the LSV1 and LSV2 genomes, the first detection of LSV4 in the US, and the discovery of LSV6 and LSV7. We detected LSV1 and LSV2 in the Varroa destructor mite, and determined that a large proportion of LSV2 is found in the honey bee gut, suggesting that vector-mediated, food-associated, and/or fecal-oral routes may be important for LSV dissemination. Pathogen-specific quantitative PCR data, obtained from samples collected during a small-scale monitoring project, revealed that LSV2, LSV1, Black queen cell virus (BQCV, and Nosema ceranae were more abundant in weak colonies than strong colonies within this sample cohort. Together, these results enhance our current understanding of LSVs and illustrate the importance of future studies aimed at investigating the role of LSVs and other pathogens on honey bee health at both the individual and colony levels.

  12. Hepatitis B virus infection in immigrant populations

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Hepatitis B virus (HBV) is the most common cause ofhepatitis worldwide, with nearly 350 million peoplechronically infected and 600000 deaths per year dueto acute liver failure occurring during acute hepatitisor, more frequently, in HBV-related liver cirrhosis orhepatocellular carcinoma. Ongoing immigration fromcountries with a high HBV endemicity to those with a lowHBV endemicity warrants particular attention to preventthe spread of HBV infection to the native population.This review article analyzes the epidemiology andvirological and clinical characteristics of HBV infectionin immigrant populations and in their host countries,and suggests prophylactic measures to prevent thespread of this infection. Among the immigrants fromdifferent geographical areas, those from South East Asiaand sub-Saharan Africa show the highest prevalencesof hepatitis B surface antigen (HBsAg) carriers, inaccordance with the high endemicity of the countriesof origin. The molecular characteristics of HBV infectionin immigrants reflect those of the geographical areasof origin HBV genotype A and D predominate inimmigrants from Eastern Europe, B and C in those fromAsia and genotype E in those from Africa. The literaturedata on the clinical course and treatment of HBsAgpositiveimmigrants are scanty. The management ofHBV infection in immigrant populations is difficult andrequires expert personnel and dedicated structures fortheir assistance. The social services, voluntary operatorsand cultural mediators are essential to achieve optimizedpsychological and clinical intervention.

  13. Oral manifestations of hepatitis C virus infection

    Science.gov (United States)

    Carrozzo, Marco; Scally, Kara

    2014-01-01

    Extrahepatic manifestations (EHMs) of hepatitis C virus (HCV) infection can affect a variety of organ systems with significant morbidity and mortality. Some of the most frequently reported EHM of HCV infection, involve the oral region predominantly or exclusively. Oral lichen planus (OLP) is a chronic inflammatory condition that is potentially malignant and represents cell-mediated reaction to a variety of extrinsic antigens, altered self-antigens, or super antigens. Robust epidemiological evidence support the link between OLP and HCV. As the virus may replicate in the oral mucosa and attract HCV-specific T lymphocytes, HCV may be implicated in OLP pathogenesis. Sjögren syndrome (SjS) is an autoimmune exocrinopathy, characterized by dryness of the mouth and eyes and a multitude of other systemic signs and symptoms. SjS patients have also an increased risk of non-Hodgkin lymphoma. Patients with chronic hepatitis C do frequently have histological signs of Sjögren-like sialadenitis with mild or even absent clinical symptoms. However, it is still unclear if HCV may cause a disease mimicking SjS or it is directly responsible for the development of SjS in a specific subset of patients. Oral squamous cell carcinoma is the most common oral malignant tumour and at least in some part of the world could be linked to HCV. PMID:24976694

  14. Oral manifestations of hepatitis C virus infection.

    Science.gov (United States)

    Carrozzo, Marco; Scally, Kara

    2014-06-28

    Extrahepatic manifestations (EHMs) of hepatitis C virus (HCV) infection can affect a variety of organ systems with significant morbidity and mortality. Some of the most frequently reported EHM of HCV infection, involve the oral region predominantly or exclusively. Oral lichen planus (OLP) is a chronic inflammatory condition that is potentially malignant and represents cell-mediated reaction to a variety of extrinsic antigens, altered self-antigens, or super antigens. Robust epidemiological evidence support the link between OLP and HCV. As the virus may replicate in the oral mucosa and attract HCV-specific T lymphocytes, HCV may be implicated in OLP pathogenesis. Sjögren syndrome (SjS) is an autoimmune exocrinopathy, characterized by dryness of the mouth and eyes and a multitude of other systemic signs and symptoms. SjS patients have also an increased risk of non-Hodgkin lymphoma. Patients with chronic hepatitis C do frequently have histological signs of Sjögren-like sialadenitis with mild or even absent clinical symptoms. However, it is still unclear if HCV may cause a disease mimicking SjS or it is directly responsible for the development of SjS in a specific subset of patients. Oral squamous cell carcinoma is the most common oral malignant tumour and at least in some part of the world could be linked to HCV. PMID:24976694

  15. Simultaneous multiplex PCR detection of seven cucurbit-infecting viruses.

    Science.gov (United States)

    Kwon, Ji Yeon; Hong, Jin Sung; Kim, Min Jea; Choi, Sun Hee; Min, Byeong Eun; Song, Eun Gyeong; Kim, Hyun Hee; Ryu, Ki Hyun

    2014-09-01

    Two multiplex polymerase chain reaction (PCR) systems using dual priming oligonucleotide (DPO) primers were developed for the simultaneous detection of seven cucurbit-infecting viruses. One system allows for the detection of papaya ringspot virus, watermelon mosaic virus, and zucchini yellow mosaic virus, whereas the other permits the detection of cucumber green mottle mosaic virus, cucumber fruit mottle mosaic virus, kyuri green mottle mosaic virus, and zucchini green mottle mosaic virus. Viral species-specific DPO primers developed in this study detected as little as 10 fg/μl of viral RNA under monoplex conditions and 10 pg/μl of viral RNA under multiplex conditions. Multiplex PCR using the DPO primer sets was capable of amplifying viral genes at annealing temperatures ranging from 53 °C to 63 °C. Whereas the use of conventional primers gave rise to non-specific bands, the DPO primers detected target viral genes in the absence of non-specific amplification. When these DPO multiplex primer sets were applied to virus-infected cucurbit samples obtained in the field, multiple infection as well as single infection was accurately identified. This novel approach could also detect multiple viruses in infected seeds. The reliability of multiplex PCR systems using DPO primers for plant virus detection is discussed. PMID:24937806

  16. Transmission potential of Zika virus infection in the South Pacific

    Directory of Open Access Journals (Sweden)

    Hiroshi Nishiura

    2016-04-01

    Conclusions: The transmissibility of Zika virus infection appears to be comparable to those of dengue and chikungunya viruses. Considering that Aedes species are a shared vector, this finding indicates that Zika virus replication within the vector is perhaps comparable to dengue and chikungunya.

  17. Highly Pathogenic Avian Influenza Virus Infection in Feral Raccoons, Japan

    OpenAIRE

    Horimoto, Taisuke; Maeda, Ken; Murakami, Shin; Kiso, Maki; Iwatsuki-Horimoto, Kiyoko; SASHIKA, Mariko; Ito, Toshihiro; Suzuki, Kazuo; Yokoyama, Mayumi; Kawaoka, Yoshihiro

    2011-01-01

    Although raccoons (Procyon lotor) are susceptible to influenza viruses, highly pathogenic avian influenza virus (H5N1) infection in these animals has not been reported. We performed a serosurvey of apparently healthy feral raccoons in Japan and found specific antibodies to subtype H5N1 viruses. Feral raccoons may pose a risk to farms and public health.

  18. Immune Activation in the Pathogenesis of Dengue Virus Infection

    NARCIS (Netherlands)

    C.A.M. van de Weg (Cornelia A.M.)

    2014-01-01

    markdownabstract__Abstract__ Dengue virus (DENV) is a positive-stranded RNA virus and belongs to the Flaviviridae family. The virus is transmitted by the bite of an infected Aedes-mosquito and circulates in tropical and subtropical areas around the world. The incidence of dengue has risen dramatica

  19. Persistent, triple-virus co-infections in mosquito cells

    Directory of Open Access Journals (Sweden)

    Malasit Prida

    2010-01-01

    Full Text Available Abstract Background It is known that insects and crustaceans can carry simultaneous, active infections of two or more viruses without showing signs of disease, but it was not clear whether co-infecting viruses occupied the same cells or different cells in common target tissues. Our previous work showed that successive challenge of mosquito cell cultures followed by serial, split-passage resulted in stabilized cultures with 100% of the cells co-infected with Dengue virus (DEN and an insect parvovirus (densovirus (DNV. By addition of Japanese encephalitis virus (JE, we tested our hypothesis that stable, persistent, triple-virus co-infections could be obtained by the same process. Results Using immunocytochemistry by confocal microscopy, we found that JE super-challenge of cells dually infected with DEN and DNV resulted in stable cultures without signs of cytopathology, and with 99% of the cells producing antigens of the 3 viruses. Location of antigens for all 3 viruses in the triple co-infections was dominant in the cell nuclei. Except for DNV, this differed from the distribution in cells persistently infected with the individual viruses or co-infected with DNV and DEN. The dependence of viral antigen distribution on single infection or co-infection status suggested that host cells underwent an adaptive process to accommodate 2 or more viruses. Conclusions Individual mosquito cells can accommodate at least 3 viruses simultaneously in an adaptive manner. The phenomenon provides an opportunity for genetic exchange between diverse viruses and it may have important medical and veterinary implications for arboviruses.

  20. Postmortem Investigations Following Human Immunodeficiency Virus Infection

    Directory of Open Access Journals (Sweden)

    Andrey V. Bychkov

    2009-04-01

    of leukemia and one case of cervical cancer. Conclusions: Tuberculosis was the most widespread among the opportunistic infections, which often had affected the entire lung and had a destructive form. In the morphological picture of tuberculous inflammation, alterative and exudative changes dominated. Moreover, HIV infection had a characteristically broad spectrum of causative agents of pneumonia, including bacteria, viruses, fungi, and protozoa.

  1. Phyllanthus species for chronic hepatitis B virus infection

    DEFF Research Database (Denmark)

    Yun, Xia; Luo, Hui; Liu, Jian Ping;

    2011-01-01

    Phyllanthus species for patients with chronic hepatitis B virus (HBV) infection have been assessed in clinical trials, but no consensus regarding their usefulness exists.......Phyllanthus species for patients with chronic hepatitis B virus (HBV) infection have been assessed in clinical trials, but no consensus regarding their usefulness exists....

  2. Quantitative Risk Assessment of Avian Influenza Virus Infection via Water

    NARCIS (Netherlands)

    Schijven FJ; Teunis PFM; Roda Husman AM de; MGB

    2006-01-01

    Using literature data, daily infection risks of chickens and humans with H5N1 avian influenza virus (AIV) by drinking water consumption were estimated for the Netherlands. A highly infectious virus and less than 4 log10 drinking water treatment (reasonably inefficient) may lead to a high infection r

  3. Symptoms of influenza virus infection in hospitalized patients

    NARCIS (Netherlands)

    van den Dool, C; Hak, E; Wallinga, J; van Loon, A M; Lammers, J W J; Bonten, M J M

    2008-01-01

    BACKGROUND: During influenza outbreaks, fever and cough are the most accurate symptoms in predicting influenza virus infection in the community. OBJECTIVE: To determine the usefulness of fever, cough, and other symptoms for diagnosing influenza virus infection in hospitalized patients. DESIGN: Prosp

  4. Zika Virus Infection Acquired During Brief Travel to Indonesia

    OpenAIRE

    Kwong, Jason C.; Druce, Julian D.; Leder, Karin

    2013-01-01

    Zika virus infection closely resembles dengue fever. It is possible that many cases are misdiagnosed or missed. We report a case of Zika virus infection in an Australian traveler who returned from Indonesia with fever and rash. Further case identification is required to determine the evolving epidemiology of this disease.

  5. Negative-strand RNA viruses: The plant-infecting counterparts

    NARCIS (Netherlands)

    Kormelink, R.J.M.; Garcia, M.L.; Goodin, M.; Sasaya, T.; Haenni, A.L.

    2011-01-01

    While a large number of negative-strand (-)RNA viruses infect animals and humans, a relative small number have plants as their primary host. Some of these have been classified within families together with animal/human infecting viruses due to similarities in particle morphology and genome organizat

  6. Zika virus infection acquired during brief travel to Indonesia.

    Science.gov (United States)

    Kwong, Jason C; Druce, Julian D; Leder, Karin

    2013-09-01

    Zika virus infection closely resembles dengue fever. It is possible that many cases are misdiagnosed or missed. We report a case of Zika virus infection in an Australian traveler who returned from Indonesia with fever and rash. Further case identification is required to determine the evolving epidemiology of this disease.

  7. Mayaro virus infection, Amazon Basin region, Peru, 2010-2013.

    Science.gov (United States)

    Halsey, Eric S; Siles, Crystyan; Guevara, Carolina; Vilcarromero, Stalin; Jhonston, Erik J; Ramal, Cesar; Aguilar, Patricia V; Ampuero, Julia S

    2013-11-01

    During 2010-2013, we recruited 16 persons with confirmed Mayaro virus infection in the Peruvian Amazon to prospectively follow clinical symptoms and serologic response over a 12-month period. Mayaro virus infection caused long-term arthralgia in more than half, similar to reports of other arthritogenic alphaviruses.

  8. Hepatitis C virus infection and risk of coronary artery disease

    DEFF Research Database (Denmark)

    Roed, Torsten; Lebech, Anne-Mette; Kjaer, Andreas;

    2012-01-01

    Several chronic infections have been associated with cardiovascular diseases, including Chlamydia pneumoniae, human immunodeficiency virus and viral hepatitis. This review evaluates the literature on the association between chronic hepatitis C virus (HCV) infection and the risk of coronary artery...... disease (CAD)....

  9. First Imported Case of Zika Virus Infection into Korea.

    Science.gov (United States)

    Jang, Hee-Chang; Park, Wan Beom; Kim, Uh Jin; Chun, June Young; Choi, Su-Jin; Choe, Pyoeng Gyun; Jung, Sook-In; Jee, Youngmee; Kim, Nam-Joong; Choi, Eun Hwa; Oh, Myoung-Don

    2016-07-01

    Since Zika virus has been spreading rapidly in the Americas from 2015, the outbreak of Zika virus infection becomes a global health emergency because it can cause neurological complications and adverse fetal outcome including microcephaly. Here, we report clinical manifestations and virus isolation findings from a case of Zika virus infection imported from Brazil. The patient, 43-year-old Korean man, developed fever, myalgia, eyeball pain, and maculopapular rash, but not neurological manifestations. Zika virus was isolated from his semen, and reverse-transcriptase PCR was positive for the virus in the blood, urine, and saliva on the 7th day of the illness but was negative on the 21st day. He recovered spontaneously without any neurological complications. He is the first case of Zika virus infection in Korea imported from Brazil.

  10. First Imported Case of Zika Virus Infection into Korea

    Science.gov (United States)

    Jee, Youngmee

    2016-01-01

    Since Zika virus has been spreading rapidly in the Americas from 2015, the outbreak of Zika virus infection becomes a global health emergency because it can cause neurological complications and adverse fetal outcome including microcephaly. Here, we report clinical manifestations and virus isolation findings from a case of Zika virus infection imported from Brazil. The patient, 43-year-old Korean man, developed fever, myalgia, eyeball pain, and maculopapular rash, but not neurological manifestations. Zika virus was isolated from his semen, and reverse-transcriptase PCR was positive for the virus in the blood, urine, and saliva on the 7th day of the illness but was negative on the 21st day. He recovered spontaneously without any neurological complications. He is the first case of Zika virus infection in Korea imported from Brazil. PMID:27366020

  11. Comparative pathology of infection by novel diarrhoea viruses.

    Science.gov (United States)

    Hall, G A

    1987-01-01

    Examination of diarrhoeic faeces in the electron microscope often reveals viruses that are presumed to be enteropathogenic. Lesions caused by novel rotaviruses were similar to those of group A rotaviruses, but enterocyte syncytia were seen which are probably pathognomonic for novel rotaviruses. In adenovirus infection in piglets, mature enterocytes were infected and destroyed; intranuclear inclusion bodies were seen in infected enterocytes. Calici-like viruses infected mature enterocytes in calves and the lesions were similar to those described in humans infected with calici-like viruses; in both host species it was impossible to demonstrate virus particles in enterocytes examined in the electron microscope. The Breda virus infected villi and crypts in the lower small intestine and the surface and crypts in the large intestine; it was the only enteropathogenic virus to show this distribution of infection and lesions. Astrovirus infection in lambs was comparable to a mild rotavirus infection, but in calves the epithelium of the dome villi of Peyer's patches was infected. Parvovirus in cats and dogs infected and destroyed small intestinal crypt cells, causing dilated crypts and stunted villi; intranuclear inclusion bodies were prominent. PMID:3036441

  12. Susceptibility of different leukocyte cell types to Vaccinia virus infection

    Directory of Open Access Journals (Sweden)

    Sánchez-Puig Juana M

    2004-11-01

    Full Text Available Abstract Background Vaccinia virus, the prototype member of the family Poxviridae, was used extensively in the past as the Smallpox vaccine, and is currently considered as a candidate vector for new recombinant vaccines. Vaccinia virus has a wide host range, and is known to infect cultures of a variety of cell lines of mammalian origin. However, little is known about the virus tropism in human leukocyte populations. We report here that various cell types within leukocyte populations have widely different susceptibility to infection with vaccinia virus. Results We have investigated the ability of vaccinia virus to infect human PBLs by using virus recombinants expressing green fluorescent protein (GFP, and monoclonal antibodies specific for PBL subpopulations. Flow cytometry allowed the identification of infected cells within the PBL mixture 1–5 hours after infection. Antibody labeling revealed that different cell populations had very different infection rates. Monocytes showed the highest percentage of infected cells, followed by B lymphocytes and NK cells. In contrast to those cell types, the rate of infection of T lymphocytes was low. Comparison of vaccinia virus strains WR and MVA showed that both strains infected efficiently the monocyte population, although producing different expression levels. Our results suggest that MVA was less efficient than WR in infecting NK cells and B lymphocytes. Overall, both WR and MVA consistently showed a strong preference for the infection of non-T cells. Conclusions When infecting fresh human PBL preparations, vaccinia virus showed a strong bias towards the infection of monocytes, followed by B lymphocytes and NK cells. In contrast, very poor infection of T lymphocytes was detected. These finding may have important implications both in our understanding of poxvirus pathogenesis and in the development of improved smallpox vaccines.

  13. Virus-Like Vesicle-Based Therapeutic Vaccine Vectors for Chronic Hepatitis B Virus Infection

    OpenAIRE

    Tracy D Reynolds; Buonocore, Linda; Rose, Nina F.; Rose, John K.; Robek, Michael D.

    2015-01-01

    More than 500,000 people die each year from the liver diseases that result from chronic hepatitis B virus (HBV) infection. Therapeutic vaccines, which aim to elicit an immune response capable of controlling the virus, offer a potential new treatment strategy for chronic hepatitis B. Recently, an evolved, high-titer vaccine platform consisting of Semliki Forest virus RNA replicons that express the vesicular stomatitis virus glycoprotein (VSV G) has been described. This platform generates virus...

  14. Seroepidemiology of Asymptomatic Dengue Virus Infection in Jeddah, Saudi Arabia

    OpenAIRE

    Jamjoom, Ghazi A.; Azhar, Esam I.; Moujahid A. Kao; Radadi, Raja M.

    2016-01-01

    BACKGROUND Although virologically confirmed dengue fever has been recognized in Jeddah, Saudi Arabia, since 1994, causing yearly outbreaks, no proper seroepidemiologic studies on dengue virus have been conducted in this region. Such studies can define the extent of infection by this virus and estimate the proportion that may result in disease. The aim of this study was to measure the seroprevalence of past dengue virus infection in healthy Saudi nationals from different areas in the city of J...

  15. Transmission potential of Zika virus infection in the South Pacific

    OpenAIRE

    Nishiura, Hiroshi; Kinoshita, Ryo; Mizumoto, Kenji; Yasuda, Yohei; Nah, Kyeongah

    2016-01-01

    Objectives: Zika virus has spread internationally through countries in the South Pacific and Americas. The present study aimed to estimate the basic reproduction number, R0, of Zika virus infection as a measurement of the transmission potential, reanalyzing past epidemic data from the South Pacific. Methods: Incidence data from two epidemics, one on Yap Island, Federal State of Micronesia in 2007 and the other in French Polynesia in 2013-2014, were reanalyzed. R0 of Zika virus infection was e...

  16. Transmission potential of Zika virus infection in the South Pacific

    OpenAIRE

    Hiroshi Nishiura; Ryo Kinoshita; Kenji Mizumoto; Yohei Yasuda; Kyeongah Nah

    2016-01-01

    Objectives: Zika virus has spread internationally through countries in the South Pacific and Americas. The present study aimed to estimate the basic reproduction number, R0, of Zika virus infection as a measurement of the transmission potential, reanalyzing past epidemic data from the South Pacific. Methods: Incidence data from two epidemics, one on Yap Island, Federal State of Micronesia in 2007 and the other in French Polynesia in 2013–2014, were reanalyzed. R0 of Zika virus infection wa...

  17. Immunomodulatory Activity of Red Ginseng against Influenza A Virus Infection

    Directory of Open Access Journals (Sweden)

    Jong Seok Lee

    2014-01-01

    Full Text Available Ginseng herbal medicine has been known to have beneficial effects on improving human health. We investigated whether red ginseng extract (RGE has preventive effects on influenza A virus infection in vivo and in vitro. RGE was found to improve survival of human lung epithelial cells upon influenza virus infection. Also, RGE treatment reduced the expression of pro-inflammatory genes (IL-6, IL-8 probably in part through interference with the formation of reactive oxygen species by influenza A virus infection. Long-term oral administration of mice with RGE showed multiple immunomodulatory effects such as stimulating antiviral cytokine IFN-γ production after influenza A virus infection. In addition, RGE administration in mice inhibited the infiltration of inflammatory cells into the bronchial lumens. Therefore, RGE might have the potential beneficial effects on preventing influenza A virus infections via its multiple immunomodulatory functions.

  18. Bovine respiratory disease model based on dual infections with infection with bovine viral diarrhea virus and bovine corona virus

    Science.gov (United States)

    Bovine respiratory disease complex (BRDC) is the leading cause of economic loss in the U.S. cattle industry. BRDC likely results from simultaneous or sequential infections with multiple pathogens including both viruses and bacteria. Bovine viral diarrhea virus (BVDV) and bovine corona virus (BoCV...

  19. Hepatitis B virus infection in children.

    LENUS (Irish Health Repository)

    O'Gorman, C S

    2012-02-01

    Recent increases in Hepatitis B virus (HBV) infection prompted us to characterize HBV-infected children in Ireland and to audit management, by reviewing prospectively gathered data. Of 46 children (29 [63%] male), median age at presentation was 8.1 years (range 0.6-17.6), monitoring duration was 22.5 months (range 1-101), 23\\/46 (50%) were European (including 9 [19.6%] Irish), 15 (32.6%) African and 9 (19.6%) Asian. Acquisition was vertical (25\\/46 [54.3%]), horizontal (5\\/46 [10.9%]), unknown (16\\/46 [34.8%]). HBV-DNA was >100,000,000 cpm in 20\\/32 (62.5%) with chronic infection. Hepatitis B e antigen (HBeAg) was detected in 32\\/44 (72.7%). We estimate that universal neonatal vaccination (UNV-HBV) could have prevented 22% of cases, and could limit further horizontal HBV spread. This supports the recent introduction of UNV-HBV.

  20. ELECTRON MICROSCOPE EVIDENCE OF VIRUS INFECTION IN CULTURED MARINE FISH

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Electron microscope investigation on the red sea bream (Pagrosomus major), bastard halibut (Paralichthys olivaceus) and stone flounder (Kareius bicoloratus) in North China revealed virus infection in the bodies of the dead and diseased fish. These viruses included the lymphocystis disease virus (LDV), parvovirus, globular virus, and a kind of baculavirus which was not discovered and reported before and is now tentatively named baculavirus of stone flounder (Kareius bicoloratus).

  1. Zika virus infections imported from Brazil to Portugal, 2015

    OpenAIRE

    L. Zé-Zé; M.B. Prata; Teixeira, T; Marques, N.; Mondragão, A.; Fernandes, R; Saraiva da Cunha, J.; Alves, M. J.

    2016-01-01

    Zika virus is an emerging arbovirus transmitted by Aedes sp. mosquitoes like the Dengue and Chikungunya viruses. Zika virus was until recently considered a mild pathogenic mosquito-borne flavivirus with very few reported benign human infections. In 2007, an epidemic in Micronesia initiated the turnover in the epidemiological history of Zika virus and more recently, the potential association with congenital microcephaly cases in Brazil 2015, still under investigation, led the World Health Orga...

  2. Avian influenza viruses - new causative a gents of human infections

    Directory of Open Access Journals (Sweden)

    Hrnjaković-Cvjetković Ivana

    2006-01-01

    Full Text Available Introduction. Influenza A viruses can infect humans, some mammals and especially birds. Subtypes of human influenza A viruses: ACH1N1, ACH2N2 and A(H3N2 have caused pandemics. Avian influenza viruses vary owing to their 15 hemagglutinins (H and 9 neuraminidases (N. Human cases of avian influenza A In the Netherlands in 2003, there were 83 human cases of influenza A (H7N7. In 1997, 18 cases of H5N1 influenza A, of whom 6 died, were found among residents of Hong Kong. In 2004, 34 human cases (23 deaths were reported in Viet Nam and Thailand. H5N1 virus-infected patients presented with fever and respiratory symptoms. Complications included respiratory distress syndrome, renal failure, liver dysfunction and hematologic disorders. Since 1999, 7 cases of human influenza H9N2 infection have been identified in China and Hong Kong. The importance of human infection with avian influenza viruses. H5N1 virus can directly infect humans. Genetic reassortment of human and avian influenza viruses may occur in humans co infected with current human A(HIN1 or A(H3N2 subtypes and avian influenza viruses. The result would be a new influenza virus with pandemic potential. All genes of H5Nl viruses isolated from humans are of avian origin. Prevention and control. The reassortant virus containing H and N from avian and the remaining proteins from human influenza viruses will probably be used as a vaccine strain. The most important control measures are rapid destruction of all infected or exposed birds and rigorous disinfection of farms. Individuals exposed to suspected animals should receive prophylactic treatment with antivirals and annual vaccination. .

  3. Infection of differentiated porcine airway epithelial cells by influenza virus: differential susceptibility to infection by porcine and avian viruses.

    Directory of Open Access Journals (Sweden)

    Darsaniya Punyadarsaniya

    Full Text Available BACKGROUND: Swine are important hosts for influenza A viruses playing a crucial role in the epidemiology and interspecies transmission of these viruses. Respiratory epithelial cells are the primary target cells for influenza viruses. METHODOLOGY/PRINCIPAL FINDINGS: To analyze the infection of porcine airway epithelial cells by influenza viruses, we established precision-cut lung slices as a culture system for differentiated respiratory epithelial cells. Both ciliated and mucus-producing cells were found to be susceptible to infection by swine influenza A virus (H3N2 subtype with high titers of infectious virus released into the supernatant already one day after infection. By comparison, growth of two avian influenza viruses (subtypes H9N2 and H7N7 was delayed by about 24 h. The two avian viruses differed both in the spectrum of susceptible cells and in the efficiency of replication. As the H9N2 virus grew to titers that were only tenfold lower than that of a porcine H3N2 virus this avian virus is an interesting candidate for interspecies transmission. Lectin staining indicated the presence of both α-2,3- and α-2,6-linked sialic acids on airway epithelial cells. However, their distribution did not correlate with pattern of virus infection indicating that staining by plant lectins is not a reliable indicator for the presence of cellular receptors for influenza viruses. CONCLUSIONS/SIGNIFICANCE: Differentiated respiratory epithelial cells significantly differ in their susceptibility to infection by avian influenza viruses. We expect that the newly described precision-cut lung slices from the swine lung are an interesting culture system to analyze the infection of differentiated respiratory epithelial cells by different pathogens (viral, bacterial and parasitic ones of swine.

  4. Occult hepatitis B virus infection in Egypt

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The emerging evidence of the potentially clinicalimportance of occult hepatitis B virus (HBV) infection(OBI) increases the interest in this topic. OBI mayimpact in several clinical contexts, which include thepossible transmission of the infection, the contributionto liver disease progression, the development ofhepatocellular carcinoma, and the risk of reactivation.There are several articles that have published on OBI inEgyptian populations. A review of MEDLINE databasewas undertaken for relevant articles to clarify theepidemiology of OBI in Egypt. HBV genotype D is theonly detectable genotype among Egyptian OBI patients.Higher rates of OBI reported among Egyptian chronicHCV, hemodialysis, children with malignant disorders, andcryptogenic liver disease patients. There is an evidenceof OBI reactivation after treatment with chemotherapy.The available data suggested that screening for OBI mustbe a routine practice in these groups of patients. Furtherstudies needed for better understand of the epidemiologyof OBI among Egyptian young generations after the eraof hepatitis B vaccination.

  5. Innate immune targets of hepatitis B virus infection

    OpenAIRE

    Zou, Zhi-Qiang; Wang, Li; Kai WANG; Yu, Ji-Guang

    2016-01-01

    Approximately 400 million people are chronically infected with hepatitis B virus (HBV) globally despite the widespread immunization of HBV vaccine and the development of antiviral therapies. The immunopathogenesis of HBV infection is initiated and driven by complexed interactions between the host immune system and the virus. Host immune responses to viral particles and proteins are regarded as the main determinants of viral clearance or persistent infection and hepatocyte injury. Innate immun...

  6. Respiratory Syncytial Virus in Lower Respiratory Tract Infections

    OpenAIRE

    Anita Chakravarti; Bineeta Kashyap

    2007-01-01

    Objective: Acute lower respiratory infections lead to high morbidity and mortality rates in children from developing countries. The aim of this study was to look into the extent of respiratory syncytial virus infections in children with special reference to the role of specific immunoglobulins in protection against infection as well as the association with bacterial pathogens. Material & Methods: Nasopharyngeal aspirates were tested for respiratory syncytial virus antigen by enzyme immunoassa...

  7. Defective interfering particles of Sindbis virus do not interfere with the homologous virus obtained from persistently infected BHK cells but do interfere with Semliki Forest virus.

    OpenAIRE

    Weiss, B; Schlesinger, S

    1981-01-01

    Defective interfering particles derived from wild-type Sindbis virus no longer interfere with the infectious virus cloned from BHK cells persistently infected with Sindbis virus for 16 months. These particles do interfere with the replication of Semliki Forest virus.

  8. Ação do radium sôbre o vírus da Coriomeningite linfocitária benigna Radium effect upon the lymphocytic choriomeningitis virus

    Directory of Open Access Journals (Sweden)

    J. Guilherme Lacorte

    1968-01-01

    Full Text Available O presente trabalho faz parte de uma seqüência iniciada em 1953 com a verificação do efeito dos raios X sôbre o vírus da gripe em que observamos que os mesmos, em doses fracas, tem aumentado o seu poder patogênico para camundongos. Posteriormente, verificamos a ação do radium sôbre o vírus da gripe e da poliomielite. Neste último caso, o vírus irradiado mostrou-se ativo durante maior número de dias. Nas pesquisas aqui referidas, submetemos o vírus da coriomeningite linfocitária benigna a ação do radium, usando quatro agulhas de 1 mg desse elemento em dispositivo que idealizamos para êste fim. Depois de irradiada, foi a suspensão de vírus diluida a 10*-1, 10*-2 e 10*-3 para as inoculações em camundongos, juntamente com as diluições testemunhas. Observamos que o vírus resistiu pelo menos 264 dias, à temperatura de 4ºC. Quanto às alterações do poder patogênico provocadas pelo radium verificamos que o mesmo não se altera após 24 horas de irradiação. Diminue após 8 dias para aumentar, de modo seguro, após 20 e 33 dias. Iguala-se ao testemunha depois de 78 dias.In the present paper the authors refered the experiments made with the lymphocytic chriomeningitis virus. We strain, after exposition to 4 tubes of 1 mg of radium. The virus suspension was put into the Carrel flask in a layer of 0,1 cm. The titrations of the irradiated virus suspension were made after 24 hours, 8, 20, 33, 78, 85, 120, 264, 292, 387 and 535 days. the virus was still active after 264 days, not after 292 days. The virus irradiated during 24 hours presented the same pathogenicity form mice than the control but after 8 days it was lesser and after 20 and 33 days it was enchanced (Graphic 10. After 78 days the pathogenic power was the same for the irradiated virus and the control.

  9. Unfolded protein response in hepatitis C virus infection

    Directory of Open Access Journals (Sweden)

    Shiu-Wan eChan

    2014-05-01

    Full Text Available Hepatitis C virus (HCV is a single-stranded, positive-sense RNA virus of clinical importance. The virus establishes a chronic infection and can progress from chronic hepatitis, steatosis to fibrosis, cirrhosis and hepatocellular carcinoma. The mechanisms of viral persistence and pathogenesis are poorly understood. Recently the unfolded protein response (UPR, a cellular homeostatic response to endoplasmic reticulum (ER stress, has emerged to be a major contributing factor in many human diseases. It is also evident that viruses interact with the host UPR in many different ways and the outcome could be pro-viral, anti-viral or pathogenic, depending on the particular type of infection. Here we present evidence for the elicitation of chronic ER stress in HCV infection. We analyze the UPR signaling pathways involved in HCV infection, the various levels of UPR regulation by different viral proteins and finally, we propose several mechanisms by which the virus provokes the UPR.

  10. Non-MHC genes influence virus clearance through regulation of the antiviral T-cell response: correlation between virus clearance and Tc and Td activity in segregating backcross progeny

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Marker, O; Thomsen, Allan Randrup

    1994-01-01

    ) was followed by measurement of footpad swelling. Ten days after virus inoculation, the animals were sacrificed and spleen virus titer together with splenic Tc activity was measured. With regard to all three parameters a continuous distribution was observed in this backcross population. However, using cutoff......To determine the mechanism by which non-MHC genes control the rate of virus clearance in mice infected with lymphocytic choriomeningitis virus, a segregating backcross population was studied. Thirty BC1 animals were infected with virus, and virus-specific delayed-type hypersensitivity (DTH...... values based on parental and F1 animals tested in parallel, 11/30 animals were assigned Tc responders, 23/30 DTH responders and 10/30 cleared virus with maximal efficiency. Comparison of responder status with regard to the different parameters revealed a strong correlation between Tc responsiveness...

  11. Antibody dependent enhancement of frog virus 3 infection

    Directory of Open Access Journals (Sweden)

    Penny Emily

    2010-02-01

    Full Text Available Abstract Background Viruses included in the family Iridoviridae are large, icosahedral, dsDNA viruses that are subdivided into 5 genera. Frog virus 3 (FV3 is the type species of the genus Ranavirus and the best studied iridovirus at the molecular level. Typically, antibodies directed against a virus act to neutralize the virus and limit infection. Antibody dependent enhancement occurs when viral antibodies enhance infectivity of the virus rather than neutralize it. Results Here we show that anti-FV3 serum present at the time of FV3 infection enhances infectivity of the virus in two non-immune teleost cell lines. We found that antibody dependent enhancement of FV3 was dependent on the Fc portion of anti-FV3 antibodies but not related to complement. Furthermore, the presence of anti-FV3 serum during an FV3 infection in a non-immune mammalian cell line resulted in neutralization of the virus. Our results suggest that a cell surface receptor specific to teleost cell lines is responsible for the enhancement. Conclusions This report represents the first evidence of antibody dependent enhancement in iridoviruses. The data suggests that anti-FV3 serum can either neutralize or enhance viral infection and that enhancement is related to a novel antibody dependent enhancement pathway found in teleosts that is Fc dependent.

  12. Characteristics of Mild Dengue Virus Infection in Thai Children

    OpenAIRE

    Yoon, In-Kyu; Srikiatkhachorn, Anon; Hermann, Laura; Buddhari, Darunee; Scott, Thomas W; Jarman, Richard G.; Aldstadt, Jared; Nisalak, Ananda; Thammapalo, Suwich; Bhoomiboonchoo, Piraya; Mammen, Mammen P.; Green, Sharone; Gibbons, Robert V.; Endy, Timothy P.; Alan L Rothman

    2013-01-01

    A four-year longitudinal cohort and geographic cluster study in rural Thailand was conducted to characterize the clinical spectrum of dengue virus (DENV) infection. Symptomatic DENV infections in the cohort were detected by active school absence–based surveillance that triggered cluster investigations around ill cohort children. Data from 189 cohort children with symptomatic DENV infection and 126 contact children in the clusters with DENV infection were analyzed. Of infected contacts, only 1...

  13. Detection of transient and persistent feline leukaemia virus infections.

    Science.gov (United States)

    Jarrett, O; Golder, M C; Stewart, M F

    1982-03-01

    A study was made of cats persistently or transiently viraemic with feline leukaemia virus (FeLV) following experimental oronasal infection. Cats of two ages were exposed to the virus. One group was infected when eight weeks old in the expectation that most of the cats would become persistently viraemic, and the second group when 16 weeks old, so that some would show signs of a transient infection and then recover. The periods following infection when virus was detectable in the blood and in the oropharynx were determined for each group. Three methods for detecting viraemia were compared: virus isolation, immunofluorescence on blood smears and an enzyme-linked immunosorbent assay (ELISA). There was good overall agreement among the three tests in detecting virus-positive cats. Virus was found sooner after infection by virus isolation than by the other methods, and virus appeared in the blood slightly sooner in cats which developed persistent viraemia than in transiently viraemic cats. Infectious FeLV was isolated from the oropharynx of all of the persistently viraemic cats, in most cases simultaneously with virus in the plasma. Virus was also isolated from the mouth of most transiently viraemic cats. Under field conditions such transient excretion of virus lasting only a few days would rarely be detected in a single sampling. This might explain how FeLV is maintained in free range urban cats in the absence of a large number of cats with persistent active FeLV infection. For routine diagnosis, immunofluorescence would appear to offer the best chance of differentiating transient and persistent infections by FeLV.

  14. Hepatitis E virus infection in the HIV-positive patient.

    Science.gov (United States)

    Debes, Jose D; Pisano, Maria Belen; Lotto, Martin; Re, Viviana

    2016-07-01

    Hepatitis E virus (HEV) is a RNA virus that can cause hepatitis. In immunocompetent individuals, infection with HEV usually leads to asymptomatic seroconversion. However, in immunosuppressed patients, such as transplant recipients, HEV can develop into a chronic infection. Studies regarding the seroprevalence and clinical implications of HEV in patients infected with the human immunodeficiency virus (HIV) are conflicting. Levels of CD4 count in blood seem to be the most widely associated risk factor, while other factors such as meat consumption or proximity to animals are less clearly associated with HEV infection. Progression to chronicity, as well as extrahepatic manifestations of HEV seem rare in HIV, and the implications of HEV in liver disease progression are poorly understood in the HIV-infected. In this review we describe the epidemiology, risk factors, and clinical implications of HEV infection in individuals infected with HIV. PMID:27243210

  15. Hemophagocytic lymphohistiocytosis associated with SFTS virus infection

    Science.gov (United States)

    Oh, Hong Sang; Kim, Moonsuk; Lee, Jeong-Ok; Kim, Haeryoung; Kim, Eu Suk; Park, Kyoung Un; Kim, Hong Bin; Song, Kyoung-Ho

    2016-01-01

    Abstract Background: Severe fever with thrombocytopenia syndrome (SFTS) is a new emerging zoonosis. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome caused by hyperinflammation. Here, we report the case of SFTS-associated HLH. Case summary: A 62-year-old man was admitted to local hospital with 8 days of fever and chill. He had leukopenia, thrombocytopenia, and developed seizure. An attending physician examined bone marrow to rule out hematologic malignancy. He was transferred to tertiary referral hospital for suspicious HLH. We decided to confirm its histologic feature for sure. Bone marrow and liver biopsy showed hemophagocyotic histiocytes. Serological tests for other infections were all negative except SFTS virus polymerase chain reactions (PCRs) as positive from serum, bone marrow, bronchoalveolar lavage fluid, and liver biopsy specimen. A definitive diagnosis was SFTS-associated HLH. During 2 weeks of conservative treatment, he succeeded in recovery from multiple organ failure. Conclusion: SFTS should be considered one of differential diagnosis of HLH. In certain endemic areas, SFTS infection deserves clinicians’ attention because it can be presented hematologic diseases as HLH. PMID:27495089

  16. Virus-induced secondary bacterial infection: a concise review

    Science.gov (United States)

    Hendaus, Mohamed A; Jomha, Fatima A; Alhammadi, Ahmed H

    2015-01-01

    Respiratory diseases are a very common source of morbidity and mortality among children. Health care providers often face a dilemma when encountering a febrile infant or child with respiratory tract infection. The reason expressed by many clinicians is the trouble to confirm whether the fever is caused by a virus or a bacterium. The aim of this review is to update the current evidence on the virus-induced bacterial infection. We present several clinical as well in vitro studies that support the correlation between virus and secondary bacterial infections. In addition, we discuss the pathophysiology and prevention modes of the virus–bacterium coexistence. A search of the PubMed and MEDLINE databases was carried out for published articles covering bacterial infections associated with respiratory viruses. This review should provide clinicians with a comprehensive idea of the range of bacterial and viral coinfections or secondary infections that could present with viral respiratory illness. PMID:26345407

  17. Infectivity of blood products from donors with occult hepatitis B virus infection

    DEFF Research Database (Denmark)

    Allain, Jean-Pierre; Mihaljevic, Ivanka; Gonzalez-Fraile, Maria Isabel;

    2013-01-01

    Occult hepatitis B virus (HBV) infection (OBI) is identified in 1:1000 to 1:50,000 European blood donations. This study intended to determine the infectivity of blood products from OBI donors.......Occult hepatitis B virus (HBV) infection (OBI) is identified in 1:1000 to 1:50,000 European blood donations. This study intended to determine the infectivity of blood products from OBI donors....

  18. Migration of activated CD8(+) T lymphocytes to sites of viral infection does not require endothelial selectins

    DEFF Research Database (Denmark)

    Bartholdy, C; Marker, O; Thomsen, Allan Randrup

    2000-01-01

    Using mice deficient of E-selectin and E/P-selectin, we have studied the requirement for endothelial selectins in extravasation of leukocytes at sites of viral infection, with major emphasis on the recruitment of virus-specific T(C)1 cells. Lymphocytic choriomeningitis virus (LCMV)-induced mening......Using mice deficient of E-selectin and E/P-selectin, we have studied the requirement for endothelial selectins in extravasation of leukocytes at sites of viral infection, with major emphasis on the recruitment of virus-specific T(C)1 cells. Lymphocytic choriomeningitis virus (LCMV......)-induced meningitis was used as our primary experimental model. Additionally, localized subdermal inflammation and virus clearance in internal organs were analyzed during LCMV infection. The generation of CD8(+) effector T cells in infected mutants was unimpaired. Quantitative and qualitative analysis...... or marginal reduction was found in E/P-sel -/- mice, compared with wild-type mice after local challenge with virus or immunodominant viral MHC class I restricted peptide, respectively. Similar results were obtained after adoptive transfer of wild-type effector cells into E/P-sel -/- recipients, whereas...

  19. Virus-specific antibodies in sera from patients with genital herpes simplex virus infection.

    OpenAIRE

    Zweerink, H J; Corey, L

    1982-01-01

    Virus-specific antibodies against a number of herpes simplex virus type 2 antigens were determined by radioimmunoprecipitation assays in sequential serum samples obtained from 12 patients with initial genital herpes simplex virus infection. The progressive appearance of antibodies to virus-specific antigens was observed; antibodies against a 130,000-molecular-weight glycoprotein complex appeared first, followed by antibodies against the major nucleocapsid polypeptide and then antibodies again...

  20. Companion Animals as a Source of Viruses for Human Beings and Food Production Animals.

    Science.gov (United States)

    Reperant, L A; Brown, I H; Haenen, O L; de Jong, M D; Osterhaus, A D M E; Papa, A; Rimstad, E; Valarcher, J-F; Kuiken, T

    2016-07-01

    Companion animals comprise a wide variety of species, including dogs, cats, horses, ferrets, guinea pigs, reptiles, birds and ornamental fish, as well as food production animal species, such as domestic pigs, kept as companion animals. Despite their prominent place in human society, little is known about the role of companion animals as sources of viruses for people and food production animals. Therefore, we reviewed the literature for accounts of infections of companion animals by zoonotic viruses and viruses of food production animals, and prioritized these viruses in terms of human health and economic importance. In total, 138 virus species reportedly capable of infecting companion animals were of concern for human and food production animal health: 59 of these viruses were infectious for human beings, 135 were infectious for food production mammals and birds, and 22 were infectious for food production fishes. Viruses of highest concern for human health included hantaviruses, Tahyna virus, rabies virus, West Nile virus, tick-borne encephalitis virus, Crimean-Congo haemorrhagic fever virus, Aichi virus, European bat lyssavirus, hepatitis E virus, cowpox virus, G5 rotavirus, influenza A virus and lymphocytic choriomeningitis virus. Viruses of highest concern for food production mammals and birds included bluetongue virus, African swine fever virus, foot-and-mouth disease virus, lumpy skin disease virus, Rift Valley fever virus, porcine circovirus, classical swine fever virus, equine herpesvirus 9, peste des petits ruminants virus and equine infectious anaemia virus. Viruses of highest concern for food production fishes included cyprinid herpesvirus 3 (koi herpesvirus), viral haemorrhagic septicaemia virus and infectious pancreatic necrosis virus. Of particular concern as sources of zoonotic or food production animal viruses were domestic carnivores, rodents and food production animals kept as companion animals. The current list of viruses provides an objective

  1. Zika virus productively infects primary human placenta-specific macrophages

    Science.gov (United States)

    Jurado, Kellie Ann; Simoni, Michael K.; Tang, Zhonghua; Uraki, Ryuta; Hwang, Jesse; Householder, Sarah; Wu, Mingjie; Lindenbach, Brett D.; Abrahams, Vikki M.; Guller, Seth; Fikrig, Erol

    2016-01-01

    The strong association of Zika virus infection with congenital defects has led to questions of how a flavivirus is capable of crossing the placental barrier to reach the fetal brain. Here, we demonstrate permissive Zika virus infection of primary human placental macrophages, commonly referred to as Hofbauer cells, and placental villous fibroblasts. We also demonstrate Zika virus infection of Hofbauer cells within the context of the tissue ex vivo using term placental villous explants. In addition to amplifying infectious virus within a usually inaccessible area, the putative migratory activities of Hofbauer cells may aid in dissemination of Zika virus to the fetal brain. Understanding the susceptibility of placenta-specific cell types will aid future work around and understanding of Zika virus–associated pregnancy complications.

  2. Zika virus productively infects primary human placenta-specific macrophages

    Science.gov (United States)

    Jurado, Kellie Ann; Simoni, Michael K.; Tang, Zhonghua; Uraki, Ryuta; Hwang, Jesse; Householder, Sarah; Wu, Mingjie; Lindenbach, Brett D.; Abrahams, Vikki M.; Guller, Seth

    2016-01-01

    The strong association of Zika virus infection with congenital defects has led to questions of how a flavivirus is capable of crossing the placental barrier to reach the fetal brain. Here, we demonstrate permissive Zika virus infection of primary human placental macrophages, commonly referred to as Hofbauer cells, and placental villous fibroblasts. We also demonstrate Zika virus infection of Hofbauer cells within the context of the tissue ex vivo using term placental villous explants. In addition to amplifying infectious virus within a usually inaccessible area, the putative migratory activities of Hofbauer cells may aid in dissemination of Zika virus to the fetal brain. Understanding the susceptibility of placenta-specific cell types will aid future work around and understanding of Zika virus–associated pregnancy complications. PMID:27595140

  3. Fibromyalgia-associated hepatitis C virus infection.

    Science.gov (United States)

    Rivera, J; de Diego, A; Trinchet, M; García Monforte, A

    1997-09-01

    The objective was to determine whether there might be an association between hepatitis C virus (HCV) chronic infection and fibromyalgia (FM). We determined the prevalence of HCV infection in 112 FM patients, in comparison with matched rheumatoid arthritis (RA) patients from the out-patient clinic of a teaching tertiary care general hospital. Furthermore, we looked for evidence of FM in 58 patients diagnosed with chronic hepatitis due to HCV, compared with matched surgery clinic patients, HCV antibodies were determined by enzyme-linked immunosorbent assay (ELISA) and recombinant immunoblot assay (RIBA). Serum RNA of HCV (HCV-RNA) was determined by polymerase chain reaction. In the group of FM patients, HCV antibodies were found by ELISA in 17 (15.2%) patients and in six (5.3%) of the RA controls (P < 0.05). RIBA was positive in 16 and indeterminate in one of the FM patients. Serum HCV-RNA was found in 13 of these FM patients. In eight (47%) FM patients, alanine aminotransferase (ALT) was normal, although HCV-RNA was detected in four (50%) of them. In the group of patients with chronic hepatitis due to HCV, all patients had HCV antibodies and the presence of HCV-RNA in serum. Within these patients, 31 (53%) had diffuse musculoskeletal pain, while six (10%) fulfilled FM diagnostic criteria. In the control group, 13/58 (22%) had diffuse musculoskeletal pain (P < 0.001), whereas only one female patient (1.7%) fulfilled FM criteria (P < 0.05). Serum ALT was 51.7 +/- 38.4 in FM patients, whereas it was 122 +/- 76.3 in patients with HCV chronic hepatitis but without FM (P < 0.001). There were no statistical differences in autoimmune markers between patients with and without FM. These data suggest that there exists an association between FM and active HCV infection in some of our patients. FM is not associated with liver damage or autoimmune markers in these patients. HCV infection should be considered in FM patients even though ALT elevations were absent.

  4. Genus Phyllanthus for chronic hepatitis B virus infection

    DEFF Research Database (Denmark)

    Liu, J; Lin, Haili; McIntosh, H

    2001-01-01

    To evaluate the efficacy and safety of genus Phyllanthus for chronic hepatitis B virus (HBV) infection we performed a systematic review of randomized clinical trials. Randomized trials comparing genus Phyllanthus vs. placebo, no intervention, general nonspecific treatment, other herbal medicine...

  5. The Impact of Wolbachia on Virus Infection in Mosquitoes

    Directory of Open Access Journals (Sweden)

    Karyn N. Johnson

    2015-11-01

    Full Text Available Mosquito-borne viruses such as dengue, West Nile and chikungunya viruses cause significant morbidity and mortality in human populations. Since current methods are not sufficient to control disease occurrence, novel methods to control transmission of arboviruses would be beneficial. Recent studies have shown that virus infection and transmission in insects can be impeded by co-infection with the bacterium Wolbachia pipientis. Wolbachia is a maternally inherited endosymbiont that is commonly found in insects, including a number of mosquito vector species. In Drosophila, Wolbachia mediates antiviral protection against a broad range of RNA viruses. This discovery pointed to a potential strategy to interfere with mosquito transmission of arboviruses by artificially infecting mosquitoes with Wolbachia. This review outlines research on the prevalence of Wolbachia in mosquito vector species and the impact of antiviral effects in both naturally and artificially Wolbachia-infected mosquitoes.

  6. Schmallenberg virus infection of ruminants: challenges and opportunities for veterinarians

    Directory of Open Access Journals (Sweden)

    Claine F

    2015-06-01

    Full Text Available François Claine, Damien Coupeau, Laetitia Wiggers, Benoît Muylkens, Nathalie Kirschvink Veterinary Department, Faculty of Sciences, Namur Research Institute for Life Sciences (NARILIS, University of Namur (UNamur, Namur, Belgium Abstract: In 2011, European ruminant flocks were infected by Schmallenberg virus (SBV leading to transient disease in adult cattle but abortions and congenital deformities in calves, lambs, and goat kids. SBV belonging to the Simbu serogroup (family Bunyaviridae and genus Orthobunyavirus was first discovered in the same region where bluetongue virus serotype 8 (BTV-8 emerged 5 years before. Both viruses are transmitted by biting midges (Culicoides spp. and share several similarities. This paper describes the current knowledge of temporal and geographical spread, molecular virology, transmission and susceptible species, clinical signs, diagnosis, prevention and control, impact on ruminant health, and productivity of SBV infection in Europe, and compares SBV infection with BTV-8 infection in ruminants. Keywords: Schmallenberg virus, Europe, ruminants, review

  7. Infection of Avian Pox Virus in Oriental Turtle-Doves

    Directory of Open Access Journals (Sweden)

    Kyung-Yeon Eo1, Young-Hoan Kim2, Kwang-Hyun Cho3, Jong-Sik Jang4, Tae-Hwan Kim5, Dongmi Kwak5 and Oh-Deog Kwon5*

    2011-10-01

    Full Text Available Three Oriental Turtle-doves (Streptopelia orientalis exhibiting lethargy, dyspnea, poor physical condition, and poor flight endurance, were rescued and referred to the Animal Health Center, Seoul Zoo, Korea. The doves had wart-like lesions on the legs and head. All of them died the following day after arrival, with the exception of one that survived for 6 days. Diphtheritic membranes on the tongue and oral mucosa were apparent at necropsy. Avian pox virus infection was suspected based on the proliferative skin lesions and oral diphtheritic lesions. Infection of the avian pox virus was confirmed by PCR using primers specific to the 4b core protein gene of avian pox virus. All cases were diagnosed with avian pox virus infection. This is believed to be the first description on natural infection of avian pox in Oriental Turtle-doves in Korea.

  8. Antibody Prophylaxis and Therapy against Nipah Virus Infection in Hamsters

    OpenAIRE

    Guillaume, V; Contamin, H.; Loth, P.; Grosjean, I.; Courbot, M. C. Georges; Deubel, V.; Buckland, R; Wild, T F

    2006-01-01

    Nipah virus (NiV), a member of the Paramyxoviridae family, causes a zoonotic infection in which the reservoir, the fruit bat, may pass the infection to pigs and eventually to humans. In humans, the infection leads to encephalitis with >40 to 70% mortality. We have previously shown that polyclonal antibody directed to either one of two glycoproteins, G (attachment protein) or F (fusion protein), can protect hamsters from a lethal infection. In the present study, we have developed monoclonal an...

  9. The Human Immunodeficiency Virus: Infectivity and Mechanisms of Pathogenesis.

    Science.gov (United States)

    Fauci, Anthony S.

    1988-01-01

    Discusses how the infection of the human immunodeficiency virus (HIV) results in a profound immunosuppression due predominantly to a selective depletion of helper/inducer T lymphocytes that express the receptor for the virus, as well as neuropsychiatric abnormalities in the brain. (TW)

  10. Serious invasive Saffold virus infections in children, 2009

    DEFF Research Database (Denmark)

    Nielsen, Alex Christian Yde; Böttiger, Blenda; Banner, Jytte;

    2012-01-01

    The first human virus in the genus Cardiovirus was described in 2007 and named Saffold virus (SAFV). Cardioviruses can cause severe infections of the myocardium and central nervous system in animals, but SAFV has not yet been convincingly associated with disease in humans. To study a possible...

  11. Neuraminidase inhibitors for influenza B virus infection: efficacy and resistance

    OpenAIRE

    Burnham, Andrew J.; Baranovich, Tatiana; Govorkova, Elena A.

    2013-01-01

    Many aspects of the biology and epidemiology of influenza B viruses are far less studied than for influenza A viruses, and one of these aspects is effectiveness and resistance to the clinically available antiviral drugs, the neuraminidase (NA) inhibitors (NAIs). Acute respiratory infections are one of the leading causes of death in children and adults, and influenza is among the few respiratory infections that can be prevented and treated by vaccination and antiviral treatment. Recent data ha...

  12. Detection, pathogenesis, and therapy of respiratory syncytial virus infections.

    OpenAIRE

    Welliver, R C

    1988-01-01

    Respiratory syncytial virus (RSV) infection is a major cause of serious lower respiratory disease in infancy and early childhood. The unique pathogenesis of lower respiratory illness due to RSV offers some intriguing clues to the role of the human immune system in both protection against and development of respiratory illness. More than any other virus, rapid diagnostic techniques have been especially successful in identifying RSV infection. Many of these techniques could be easily adaptable ...

  13. Ocular syphilis in patients with Human Immunodeficiency Virus infection.

    Science.gov (United States)

    Mitchell, John P; Huang, Lynn L; Rosberger, Daniel F

    2015-06-01

    As Acquired Immunodeficiency Disease (AIDS) turns thirty-years old, much progress has been made. 56,000 new cases of the Human Immunodeficiency Virus (HIV) infection are expected in Americans this year. At least half or more will be in African Americans. Reports of the association between syphilis and HIV infection are well documented. We present a case of bilateral optic neuritis and panuveitis as the initial presentation in a previously undiagnosed patient with human immunodeficiency virus (HIV) and syphilis. PMID:27269502

  14. Naturally Occurring Animal Models of Human Hepatitis E Virus Infection

    OpenAIRE

    Yugo, Danielle M.; Cossaboom, Caitlin M.; Meng, Xiang-Jin

    2014-01-01

    Hepatitis E virus (HEV) is a single-stranded, positive-sense RNA virus in the family Hepeviridae. Hepatitis E caused by HEV is a clinically important global disease. There are currently four well-characterized genotypes of HEV in mammalian species, although numerous novel strains of HEV likely belonging to either new genotypes or species have recently been identified from several other animal species. HEV genotypes 1 and 2 are limited to infection in humans, whereas genotypes 3 and 4 infect a...

  15. Analysis of resistance and tolerance to virus infection in Drosophila.

    Science.gov (United States)

    Merkling, Sarah H; van Rij, Ronald P

    2015-07-01

    Host defense to virus infection involves both resistance mechanisms that reduce viral burden and tolerance mechanisms that limit detrimental effects of infection. The fruit fly, Drosophila melanogaster, has emerged as a model for identifying and characterizing the genetic basis of resistance and tolerance. This protocol describes how to analyze host responses to virus infection in Drosophila, and it covers the preparation of virus stocks, experimental inoculation of flies and assessment of host survival and virus production, which are indicative of resistance or tolerance. It also provides guidance on how to account for recently identified confounding factors, including natural genetic variation in the pastrel locus and contamination of fly stocks with persistent viruses and the symbiotic bacterium Wolbachia. Our protocol aims to be accessible to newcomers to the field and, although optimized for virus research using Drosophila, some of the techniques could be adapted to other host organisms and/or other microbial pathogens. Preparation of fly stocks requires ∼1 month, virus stock preparation requires 17-20 d, virus injection and survival assays require 10-15 d and virus titration requires 14 d.

  16. Easy and Rapid Detection of Mumps Virus by Live Fluorescent Visualization of Virus-Infected Cells.

    Science.gov (United States)

    Takahashi, Tadanobu; Agarikuchi, Takashi; Kurebayashi, Yuuki; Shibahara, Nona; Suzuki, Chihiro; Kishikawa, Akiko; Fukushima, Keijo; Takano, Maiko; Suzuki, Fumie; Wada, Hirohisa; Otsubo, Tadamune; Ikeda, Kiyoshi; Minami, Akira; Suzuki, Takashi

    2015-01-01

    Mumps viruses show diverse cytopathic effects (CPEs) of infected cells and viral plaque formation (no CPE or no plaque formation in some cases) depending on the viral strain, highlighting the difficulty in mumps laboratory studies. In our previous study, a new sialidase substrate, 2-(benzothiazol-2-yl)-4-bromophenyl 5-acetamido-3,5-dideoxy-α-D-glycero-D-galacto-2-nonulopyranosidonic acid (BTP3-Neu5Ac), was developed for visualization of sialidase activity. BTP3-Neu5Ac can easily and rapidly perform histochemical fluorescent visualization of influenza viruses and virus-infected cells without an antiviral antibody and cell fixation. In the present study, the potential utility of BTP3-Neu5Ac for rapid detection of mumps virus was demonstrated. BTP3-Neu5Ac could visualize dot-blotted mumps virus, virus-infected cells, and plaques (plaques should be called focuses due to staining of infected cells in this study), even if a CPE was not observed. Furthermore, virus cultivation was possible by direct pick-up from a fluorescent focus. In conventional methods, visible appearance of the CPE and focuses often requires more than 6 days after infection, but the new method with BTP3-Neu5Ac clearly visualized infected cells after 2 days and focuses after 4 days. The BTP3-Neu5Ac assay is a precise, easy, and rapid assay for confirmation and titration of mumps virus.

  17. Easy and Rapid Detection of Mumps Virus by Live Fluorescent Visualization of Virus-Infected Cells.

    Directory of Open Access Journals (Sweden)

    Tadanobu Takahashi

    Full Text Available Mumps viruses show diverse cytopathic effects (CPEs of infected cells and viral plaque formation (no CPE or no plaque formation in some cases depending on the viral strain, highlighting the difficulty in mumps laboratory studies. In our previous study, a new sialidase substrate, 2-(benzothiazol-2-yl-4-bromophenyl 5-acetamido-3,5-dideoxy-α-D-glycero-D-galacto-2-nonulopyranosidonic acid (BTP3-Neu5Ac, was developed for visualization of sialidase activity. BTP3-Neu5Ac can easily and rapidly perform histochemical fluorescent visualization of influenza viruses and virus-infected cells without an antiviral antibody and cell fixation. In the present study, the potential utility of BTP3-Neu5Ac for rapid detection of mumps virus was demonstrated. BTP3-Neu5Ac could visualize dot-blotted mumps virus, virus-infected cells, and plaques (plaques should be called focuses due to staining of infected cells in this study, even if a CPE was not observed. Furthermore, virus cultivation was possible by direct pick-up from a fluorescent focus. In conventional methods, visible appearance of the CPE and focuses often requires more than 6 days after infection, but the new method with BTP3-Neu5Ac clearly visualized infected cells after 2 days and focuses after 4 days. The BTP3-Neu5Ac assay is a precise, easy, and rapid assay for confirmation and titration of mumps virus.

  18. Circulating intercellular adhesion molecule-1 (ICAM-1) as an early and sensitive marker for virus-induced T cell activation

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Johansen, J; Marker, O;

    1995-01-01

    The effect of systemic virus infection on the level of circulating ICAM-1 (cICAM-1) in serum, and the role of virus-activated T cells in this context, were studied using the murine lymphocytic choriomeningitis virus infection as primary model system. A marked virus-induced elevation in cICAM-1...... in serum was revealed, the presence of which coincided with the phase of virus-induced T cell activation. However, high levels of cICAM-1 in serum were observed well before maximal T cell activation could be demonstrated. No increase in cICAM-1 was observed in the serum of infected T cell-deficient nude...... induce shedding of ICAM-1 into the circulation, and this parameter may be used as an early and sensitive marker for immune activation....

  19. Infectious salmon anaemia virus (ISAV) mucosal infection in Atlantic salmon.

    Science.gov (United States)

    Aamelfot, Maria; McBeath, Alastair; Christiansen, Debes H; Matejusova, Iveta; Falk, Knut

    2015-01-01

    All viruses infecting fish must cross the surface mucosal barrier to successfully enter a host. Infectious salmon anaemia virus (ISAV), the causative agent of the economically important infectious salmon anaemia (ISA) in Atlantic salmon, Salmo salar L., has been shown to use the gills as its entry point. However, other entry ports have not been investigated despite the expression of virus receptors on the surface of epithelial cells in the skin, the gastrointestinal (GI) tract and the conjunctiva. Here we investigate the ISAV mucosal infection in Atlantic salmon after experimental immersion (bath) challenge and in farmed fish collected from a confirmed outbreak of ISA in Norway. We show for the first time evidence of early replication in several mucosal surfaces in addition to the gills, including the pectoral fin, skin and GI tract suggesting several potential entry points for the virus. Initially, the infection is localized and primarily infecting epithelial cells, however at later stages it becomes systemic, infecting the endothelial cells lining the circulatory system. Viruses of low and high virulence used in the challenge revealed possible variation in virus progression during infection at the mucosal surfaces. PMID:26490835

  20. Zika virus infections imported from Brazil to Portugal, 2015.

    Science.gov (United States)

    Zé-Zé, L; Prata, M B; Teixeira, T; Marques, N; Mondragão, A; Fernandes, R; Saraiva da Cunha, J; Alves, M J

    2016-01-01

    Zika virus is an emerging arbovirus transmitted by Aedes sp. mosquitoes like the Dengue and Chikungunya viruses. Zika virus was until recently considered a mild pathogenic mosquito-borne flavivirus with very few reported benign human infections. In 2007, an epidemic in Micronesia initiated the turnover in the epidemiological history of Zika virus and more recently, the potential association with congenital microcephaly cases in Brazil 2015, still under investigation, led the World Health Organization (WHO) to declare a Public Health Emergency of International Concern on February 1, 2016. Here, we present the clinical and laboratory aspects related to the first four imported human cases of Zika virus in Portugal from Brazil, and alert, regarding the high level of traveling between Portugal and Brazil, and the ongoing expansion of this virus in the Americas, for the threat for Zika virus introduction in Europe and the possible introduction to Madeira Island where Aedes aegypti is present. PMID:27134823

  1. Occurrence and distribution of viruses infecting the bean in Serbia

    Directory of Open Access Journals (Sweden)

    Petrović Dragana

    2010-01-01

    Full Text Available This work describes the incidence and distribution of the most important bean viruses in Serbia: Bean common mosaic virus (BCMV, Bean common mosaic necrosis virus (BCMNV, Bean yellow mosaic virus (BYMV, Cucumber mosaic virus (CMV and Alfalfa mosaic virus (AMV. The viral isolates were characterized serologically and biologically. BCMV was found in the largest number of plants (30.53%, followed by BCMNV (2.67%, CMV (5.34%, and AMV (3.41%, since BYMV was not determined. Mixed viral infections were found in several samples. The RT-PCR method was used to prove that the tested isolates belong to the BCMV, family Potyviridae and strains Russian and NL-3 D. Results obtained in this work will enable further studies of the genetic variability of bean virus isolates from Serbia. .

  2. First case of imported Zika virus infection in Spain.

    Science.gov (United States)

    Bachiller-Luque, Pablo; Domínguez-Gil González, Marta; Álvarez-Manzanares, Jesús; Vázquez, Ana; De Ory, Fernando; Sánchez-Seco Fariñas, M Paz

    2016-04-01

    We report a case of Zika virus (ZIKV) infection in a patient with diarrhea, fever, synovitis, non-purulent conjunctivitis, and with discreet retro-orbital pain, after returning from Colombia in January 2016. The patient referred several mosquito bites. Presence of ZIKV was detected by PCR (polymerase chain reaction) in plasma. Rapid microbiological diagnosis of ZIKV infection is needed in European countries with circulation of its vector, in order to avoid autochthonous circulation. The recent association of ZIKV infection with abortion and microcephaly, and a Guillain-Barré syndrome highlights the need for laboratory differentiation of ZIKV from other virus infection. Women with potential risk for Zika virus infection who are pregnant or planning to become pregnant must mention that fact during prenatal visits in order to be evaluated and properly monitored. PMID:26994814

  3. First case of imported Zika virus infection in Spain.

    Science.gov (United States)

    Bachiller-Luque, Pablo; Domínguez-Gil González, Marta; Álvarez-Manzanares, Jesús; Vázquez, Ana; De Ory, Fernando; Sánchez-Seco Fariñas, M Paz

    2016-04-01

    We report a case of Zika virus (ZIKV) infection in a patient with diarrhea, fever, synovitis, non-purulent conjunctivitis, and with discreet retro-orbital pain, after returning from Colombia in January 2016. The patient referred several mosquito bites. Presence of ZIKV was detected by PCR (polymerase chain reaction) in plasma. Rapid microbiological diagnosis of ZIKV infection is needed in European countries with circulation of its vector, in order to avoid autochthonous circulation. The recent association of ZIKV infection with abortion and microcephaly, and a Guillain-Barré syndrome highlights the need for laboratory differentiation of ZIKV from other virus infection. Women with potential risk for Zika virus infection who are pregnant or planning to become pregnant must mention that fact during prenatal visits in order to be evaluated and properly monitored.

  4. Infection of Mosquito Cells (C6/36) by Dengue-2 Virus Interferes with Subsequent Infection by Yellow Fever Virus.

    Science.gov (United States)

    Abrao, Emiliana Pereira; da Fonseca, Benedito Antônio Lopes

    2016-02-01

    Dengue is one of the most important diseases caused by arboviruses in the world. Yellow fever is another arthropod-borne disease of great importance to public health that is endemic to tropical regions of Africa and the Americas. Both yellow fever and dengue viruses are flaviviruses transmitted by Aedes aegypti mosquitoes, and then, it is reasonable to consider that in a given moment, mosquito cells could be coinfected by both viruses. Therefore, we decided to evaluate if sequential infections of dengue and yellow fever viruses (and vice-versa) in mosquito cells could affect the virus replication patterns. Using immunofluorescence and real-time PCR-based replication assays in Aedes albopictus C6/36 cells with single or sequential infections with both viruses, we demonstrated the occurrence of viral interference, also called superinfection exclusion, between these two viruses. Our results show that this interference pattern is particularly evident when cells were first infected with dengue virus and subsequently with yellow fever virus (YFV). Reduction in dengue virus replication, although to a lower extent, was also observed when C6/36 cells were initially infected with YFV followed by dengue virus infection. Although the importance that these findings have on nature is unknown, this study provides evidence, at the cellular level, of the occurrence of replication interference between dengue and yellow fever viruses and raises the question if superinfection exclusion could be a possible explanation, at least partially, for the reported lack of urban yellow fever occurrence in regions where a high level of dengue transmission occurs.

  5. Prevalence of Hepatitis D Virus Infection Among Hepatitis B Virus Infected Patients in Qom Province, Center of Iran

    OpenAIRE

    Mohammad-Reza Ghadir; Mojtaba Belbasi; Akram Heidari; Seyed Saeid Sarkeshikian; Alireza Kabiri; Amir Hossein Ghanooni; Abolfazl Iranikhah; Maryam Vaez-Javadi; Seyed-Moayed Alavian

    2012-01-01

    Background: Hepatitis D virus (HDV) is a defective RNA virus that depends on the hepatitis B surface antigen (HBsAg) of hepatitis B virus for its replication, developing exclusively in patients with acute or chronic hepatitis B. There are little data regarding the routes of HDV transmission in Iran. The risk factors for HDV infection in Iran are blood transfusion, surgery, family history, Hejamat wet cupping (traditional phlebotomy), tattooing, war injury, dental interventions, and endoscopy....

  6. Alarming incidence of hepatitis C virus re-infection after treatment of sexually acquired acute hepatitis C virus infection in HIV-infected MSM

    NARCIS (Netherlands)

    F.A.E. Lambers; M. Prins; X. Thomas; R. Molenkamp; D. Kwa; K. Brinkman; J.T.M. van der Meer; J. Schinkel

    2011-01-01

    Recent data indicate that seroprevalence of sexually transmitted hepatitis C virus (HCV) infection among MSM is stabilizing in Amsterdam. However, little is known about the incidence of HCV re-infection in MSM who have cleared their HCV infection. We, therefore, studied the incidence of re-infection

  7. Cats as a potential source of emerging influenza virus infections

    Institute of Scientific and Technical Information of China (English)

    Taisuke; Horimoto; Fumihiro; Gen; Shin; Murakami; Kiyoko; Iwatsuki-Horimoto; Kentaro; Kato; Masaharu; Hisasue; Masahiro; Sakaguchi; Chairul; A.; Nidom; Yoshihiro; Kawaoka

    2015-01-01

    <正>Dear Editor,Historically,the influenza virus has not been regarded as a major pathogen of cats.However,since 2003,natural infections of domestic cats with highly pathogenic H5N1 avian virus causing fatal cases have been reported(Songserm et al.,2006;Yingst et al.,2006;Klopfleisch et al.,2007).Furthermore,infections of this animal with A(H1N1)pdm09 virus,causing respiratory illness with some fatal cases,have also been reported in various parts

  8. Chronic West Nile virus infection in kea (Nestor notabilis).

    Science.gov (United States)

    Bakonyi, Tamás; Gajdon, Gyula K; Schwing, Raoul; Vogl, Wolfgang; Häbich, Annett-Carolin; Thaller, Denise; Weissenböck, Herbert; Rudolf, Ivo; Hubálek, Zdenek; Nowotny, Norbert

    2016-02-01

    Six kea (Nestor notabilis) in human care, naturally infected with West Nile virus (WNV) lineage 2 in Vienna, Austria, in 2008, developed mild to fatal neurological signs. WNV RNA persisted and the virus evolved in the birds' brains, as demonstrated by (phylo)genetic analyses of the complete viral genomes detected in kea euthanized between 2009 and 2014. WNV antibodies persisted in the birds, too. Chronic WNV infection in the brain might contribute to the circulation of the virus through oral transmission to predatory birds.

  9. Experimental evidence of hepatitis A virus infection in pigs.

    Science.gov (United States)

    Song, Young-Jo; Park, Woo-Jung; Park, Byung-Joo; Kwak, Sang-Woo; Kim, Yong-Hyeon; Lee, Joong-Bok; Park, Seung-Yong; Song, Chang-Seon; Lee, Sang-Won; Seo, Kun-Ho; Kang, Young-Sun; Park, Choi-Kyu; Song, Jae-Young; Choi, In-Soo

    2016-04-01

    Hepatitis A virus (HAV) is the leading cause of acute viral hepatitis worldwide, with HAV infection being restricted to humans and nonhuman primates. In this study, HAV infection status was serologically determined in domestic pigs and experimental infections of HAV were attempted to verify HAV infectivity in pigs. Antibodies specific to HAV or HAV-like agents were detected in 3.5% of serum samples collected from pigs in swine farms. When the pigs were infected intravenously with 2 × 10(5) 50% tissue culture infectious dose (TCID50 ) of HAV, shedding of the virus in feces, viremia, and seroconversion were detected. In pigs orally infected with the same quantity of HAV, viral shedding was detected only in feces. HAV genomic RNA was detected in the liver and bile of intravenously infected pigs, but only in the bile of orally infected pigs. In further experiments, pigs were intravenously infected with 6 × 10(5) TCID50 of HAV. Shedding of HAV in feces, along with viremia and seroconversion, were confirmed in infected pigs but not in sentinel pigs. HAV genomic RNA was detected in the liver, bile, spleen, lymph node, and kidney of the infected pigs. HAV antigenomic RNA was detected in the spleen of one HAV-infected pig, suggesting HAV replication in splenic cells. Infiltration of inflammatory cells was observed in the livers of infected pigs but not in controls. This is the first experimental evidence to demonstrate that human HAV strains can infect pigs.

  10. Canine distemper virus infection in a lesser grison (Galictis cuja: first report and virus phylogeny

    Directory of Open Access Journals (Sweden)

    Jane Megid

    2013-02-01

    Full Text Available Infectious diseases in wild animals have been increasing as a result of their habitat alterations and closer contact with domestic animals. Canine distemper virus (CDV has been reported in several species of wild carnivores, presenting a threat to wildlife conservation. We described the first case of canine distemper virus infection in lesser grison (Galictis cuja. A free-ranging individual, with no visible clinical sigs, presented sudden death after one day in captivity. Molecular diagnosis for CDV infection was performed using whole blood collected by postmortem intracardiac puncture, which resulted positive. The virus phylogeny indicated that domestic dogs were the probable source of infection.

  11. Occurrence of viruses infecting pea in Iran.

    Science.gov (United States)

    Esfandiari, N; Kohi-Habibi, M; Mosahebi, Gh

    2006-01-01

    A survey was conducted to determine the incidence of Alfalfa mosaic virus (AMV), Bean yellow mosaic virus (BYMV), Broad bean wilt virus-1 (BBWV), Pea leafroll virus (PLRV), Pea enation mosaic virus (PEMV), Pea seed borne mosaic virus (PSbMV), Potato virus x(PVX), Tomato mosaic virus (ToMV), Tomato spotted wilt virus (TSWV) on pea (Pisum sativum) in Iran. A Total of 1276 random and 684 symptomatic pea samples were collected during the spring and summer of 2002-2004 in Tehran province of Iran, where pea is grown, and tested by enzyme-linked immunosorbent assay (ELISA) using specific polyclonal antibodies. Serological diagnoses were confirmed by electron microscopy and host range studies. Incidence of viruses in decreasing order was PVX (69%), ToMV (59%), PSbMV (36.6%), BBWV-1 (26.1%), BYMV (20.3%), AMV (17.77%), TSWV (12.6%), PEMV (10.9%), PLRV (6.78%). In this survey, natural occurrence of AMV, BBWV-1, PSbMV, TSWV, PVX and ToMV was reported for the first time on the pea in Iran. PMID:17390891

  12. Preference by a virus vector for infected plants is reversed after virus acquisition.

    Science.gov (United States)

    Rajabaskar, Dheivasigamani; Bosque-Pérez, Nilsa A; Eigenbrode, Sanford D

    2014-06-24

    Pathogens and their vectors can interact either directly or indirectly via their shared hosts, with implications for the persistence and spread of the pathogen in host populations. For example, some plant viruses induce changes in host plants that cause the aphids that carry these viruses to settle preferentially on infected plants. Furthermore, relative preference by the vector for infected plants can change to a preference for noninfected plants after virus acquisition by the vector, as has recently been demonstrated in the wheat-Rhopalosiphum padi-Barley yellow dwarf virus pathosystem. Here we document a similar dynamic in the potato-Myzus persicae (Sulzer)-Potato leaf roll virus (PLRV) pathosystem. Specifically, in a dual choice bioassay, nonviruliferous apterous M. persicae settled preferentially on or near potato plants infected with PLRV relative to noninfected (sham-inoculated) control plants, whereas viruliferous M. persicae (carrying PLRV) preferentially settled on or near sham-inoculated potato plants relative to infected plants. The change in preference after virus acquisition also occurred in response to trapped headspace volatiles, and to synthetic mimics of headspace volatile blends from PLRV-infected and sham-inoculated potato plants. The change in preference we document should promote virus spread by increasing rates of virus acquisition and transmission by the vector. PMID:24269348

  13. Generation of Anti-platelet Autoantibody During Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Huan-Yao Lei

    2008-01-01

    Full Text Available Dengue virus infection causes dengue fever, Dengue Hemorrhagic Fever (DHF and Dengue Shock Syndrome (DSS. Thrombocytopenia is common in dengue fever and is always found in DHF/DSS. The pathogenesis of thrombocytopenia is poorly understood. To further understand the relationship between anti-dengue virus antibody and anti-platelet antibody, we generated monoclonal anti-dengue virus antibodies from the dengue virus infected mice that developed transient thrombocytopenia post dengue infection. The analysis of a panel of monoclonal anti-NS-1 antibodies reveals three different patterns of platelet binding: strong, intermediate, or dull. Their isotypes are different, some are IgM while others are IgG1. Most of anti-platelet antibodies are cross-reactive with NS-1 of dengue virus and can be competitively inhibited by recombinant NS-1 protein, suggesting a molecular mimicry between dengue virus NS-1 protein and platelet. A clone, 13-F4-G5, preferentially bound activated platelets, can recognize two or three proteins around 150 kD on platelets. The binding to platelet would lyse the platelet in the presence of complement or enhance the ADP-induced platelet aggregation. Furthermore, some of these monoclonal antibodies would also react with the cellular antigens of BHK. Based on the data, we conclude that dengue virus infection induces auto anti-platelet antibodies which thereafter may involve in the manifestation of thrombocytopenia. A molecular mimicry between NS-1 and platelet is demonstrated.

  14. Sheep persistently infected with Border disease readily transmit virus to calves seronegative to BVD virus.

    Science.gov (United States)

    Braun, U; Reichle, S F; Reichert, C; Hässig, M; Stalder, H P; Bachofen, C; Peterhans, E

    2014-01-10

    Bovine viral diarrhea- and Border disease viruses of sheep belong to the highly diverse genus pestivirus of the Flaviviridae. Ruminant pestiviruses may infect a wide range of domestic and wild cloven-hooved mammals (artiodactyla). Due to its economic importance, programs to eradicate bovine viral diarrhea are a high priority in the cattle industry. By contrast, Border disease is not a target of eradication, although the Border disease virus is known to be capable of also infecting cattle. In this work, we compared single dose experimental inoculation of calves with Border disease virus with co-mingling of calves with sheep persistently infected with this virus. As indicated by seroconversion, infection was achieved only in one out of seven calves with a dose of Border disease virus that was previously shown to be successful in calves inoculated with BVD virus. By contrast, all calves kept together with persistently infected sheep readily became infected with Border disease virus. The ease of viral transmission from sheep to cattle and the antigenic similarity of bovine and ovine pestiviruses may become a problem for demonstrating freedom of BVD by serology in the cattle population. PMID:24315041

  15. Zika Virus Infection and Development of a Murine Model.

    Science.gov (United States)

    Shah, Ankit; Kumar, Anil

    2016-08-01

    In view of the recent outbreak of Zika virus (ZIKV), there is an urgent need to investigate the pathogenesis of the symptoms associated with ZIKV infection. Since the first identification of the virus in 1947, the pathologies associated with ZIKV infection were thought to be limited with mild illness that presented fever, rashes, muscle aches, and weakness. However, ZIKV infection has been shown to cause Guillain-Barré Syndrome, and numerous cases of congenital microcephaly in children have been reported when pregnant females were exposed to the virus. The severity and the rate of spread of ZIKV in the last year has drawn alarming interest among researchers to investigate murine models to study viral pathogenesis and develop candidate vaccines. A recent study by Lazear and colleagues, in the May 2016 issue of cell host and microbe, is an effort to study the pathogenesis of contemporary and historical virus strains in various mouse models. PMID:27260223

  16. Evidence of Apis cerana sacbrood virus infection in Apis mellifera

    Science.gov (United States)

    Sacbrood virus (SBV) is one of the most serious threats to Apis cerana but is much less destructive to Apis mellifera. In previous studies, SBV isolates infecting A. cerana and A. mellifera were identified as different serotypes, suggesting a species-barrier of SBV infection. In order to clarify whe...

  17. ZIKA VIRUS INFECTION; VERTICAL TRANSMISSION AND FOETAL CONGENITAL ANOMALIES.

    Science.gov (United States)

    Abbasi, Aziz-un-Nisa

    2016-01-01

    Zika virus (ZIKV) is an arbovirus belonging to flaviviridae family that includes Dengue, West Nile, and Yellow Fever among others. Zika virus was first discovered in 1947 in Zika forest of Uganda. It is a vector borne disease, which has been sporadically reported mostly from Africa, Pacific islands and Southeast Asia since its discovery. ZIKV infection presents as a mild illness with symptoms lasting for several days to a week after the bite of an infected mosquito. Majority of the patients have low grade fever, rash, headaches, joints pain, myalgia, and flu like symptoms. Pregnant women are more vulnerable to ZIKV infection and serious congenital anomalies can occur in foetus through trans-placental transmission. The gestation at which infection is acquired is important. Zika virus infection acquired in early pregnancy poses greater risk. There is no evidence so far about transmission through breast milk. Foetal microcephaly, Gillian Barre syndrome and other neurological and autoimmune syndromes have been reported in areas where Zika outbreaks have occurred. As infection is usually very mild no specific treatment is required. Pregnant women may be advised to take rest, get plenty of fluids. For fever and pain they can take antipyretics like paracetamol. So far no specific drugs or vaccines are available against Zika Virus Infection so prevention is the mainstay against this diseases. As ZIKV infection is a vector borne disease, prevention can be a multi-pronged strategy. These entail vector control interventions, personal protection, environmental sanitation and health education among others.

  18. Analysis of resistance and tolerance to virus infection in Drosophila

    NARCIS (Netherlands)

    Merkling, S.H.; Rij, R.P. van

    2015-01-01

    Host defense to virus infection involves both resistance mechanisms that reduce viral burden and tolerance mechanisms that limit detrimental effects of infection. The fruit fly, Drosophila melanogaster, has emerged as a model for identifying and characterizing the genetic basis of resistance and tol

  19. ZIKA VIRUS INFECTION; VERTICAL TRANSMISSION AND FOETAL CONGENITAL ANOMALIES.

    Science.gov (United States)

    Abbasi, Aziz-un-Nisa

    2016-01-01

    Zika virus (ZIKV) is an arbovirus belonging to flaviviridae family that includes Dengue, West Nile, and Yellow Fever among others. Zika virus was first discovered in 1947 in Zika forest of Uganda. It is a vector borne disease, which has been sporadically reported mostly from Africa, Pacific islands and Southeast Asia since its discovery. ZIKV infection presents as a mild illness with symptoms lasting for several days to a week after the bite of an infected mosquito. Majority of the patients have low grade fever, rash, headaches, joints pain, myalgia, and flu like symptoms. Pregnant women are more vulnerable to ZIKV infection and serious congenital anomalies can occur in foetus through trans-placental transmission. The gestation at which infection is acquired is important. Zika virus infection acquired in early pregnancy poses greater risk. There is no evidence so far about transmission through breast milk. Foetal microcephaly, Gillian Barre syndrome and other neurological and autoimmune syndromes have been reported in areas where Zika outbreaks have occurred. As infection is usually very mild no specific treatment is required. Pregnant women may be advised to take rest, get plenty of fluids. For fever and pain they can take antipyretics like paracetamol. So far no specific drugs or vaccines are available against Zika Virus Infection so prevention is the mainstay against this diseases. As ZIKV infection is a vector borne disease, prevention can be a multi-pronged strategy. These entail vector control interventions, personal protection, environmental sanitation and health education among others. PMID:27323550

  20. Dengue virus life cycle : viral and host factors modulating infectivity

    NARCIS (Netherlands)

    Rodenhuis-Zybert, Izabela A.; Wilschut, Jan; Smit, Jolanda M.

    2010-01-01

    Dengue virus (DENV 1-4) represents a major emerging arthropod-borne pathogen. All four DENV serotypes are prevalent in the (sub) tropical regions of the world and infect 50-100 million individuals annually. Whereas the majority of DENV infections proceed asymptomatically or result in self-limited de

  1. Occult hepatitis C virus infection is more common than hepatitis B infection in maintenance hemodialysis patients

    Institute of Scientific and Technical Information of China (English)

    Pankaj Jain; Sandeep Nijhawan

    2008-01-01

    Patients of end stage renal disease on maintenance hemodialysis were enrolled to study the prevalence of occult and dual hepatitis B virus (HBV) and hepatitis C virus (HCV) infection and non-occult hepatitis B and C virus infection. One hundred and two patients were enrolled. Thirty patients had HCV infection, three of them were positive in anti-HCV. So, 27 (90%) of HCVpositive patients had occult HCV infection. Eleven (11%)patients had HBV infection. Five patients were positive in anti-HBc or HBV-DNA, but negative in HBsAg (occult HBV infection). Three (3%) patients had dual HBV and HCV infection. None of the patients showed changes in viral markers during the follow-up of 8 mo on average (1-12 mo).

  2. [Dementia and human inmmunodeficiency virus infection].

    Science.gov (United States)

    Gray, F

    1998-01-01

    HIV-associated neurological manifestations: dementia, myelopathy, and neuropathy, have become one of the commonest causes of neurological disorders in young people. Cognitive impairment develops in about 30 p. 100 of patients with AIDS and frank dementia in 15 to 20 p. 100 with an annual incidence after AIDS of approximatively 7 p. 100. Typically, the onset of dementia is relatively abrupt over a few weeks or months. The clinical manifestations of the encephalopathy now termed "HIV-dementia", suggest predominant subcortical or frontal involvement. Typical presentation includes apathy and inertia, memory loss and cognitive slowing, minor depressive symptoms and withdrawal from usual activities. Neurological examination may show hypertonia of lower limbs, tremor, clonus, frontal release signs and hyperactive reflexes. Terminally, the patient is bedbound, incontinent, abulic or mute with decorticate posturing leading to death over 3 to 6 months. However, a stabilisation and even a regression of the cognitive disorders have been observed following antiretroviral treatment. Radiological features of HIV dementia include both central and cortical atrophy and white matter rarefaction. However they are neither invariable nor specific. Together with CSF examination, they are more important to exclude opportunistic infections. Indeed, although a completely normal CSF profile may reasonably exclude the diagnosis; at present, no single test or combination of tests can reliably diagnose HIV dementia. Although the clinical characteristics of HIV-dementia are now clearly established, its pathogenesis is unclear and its pathological counterpart remains a matter of debate. A number of "HIV-induced" lesions may be found in the brain of AIDS patients and their causative role in HIV-dementia has been considered. They include HIV encephalitis due to productive CNS infection by the virus, diffuse white matter pallor "HIV-leukoencephalopathy" reflecting an abnormality of the blood brain

  3. Virus-induced secondary bacterial infection: a concise review

    Directory of Open Access Journals (Sweden)

    Hendaus MA

    2015-08-01

    Full Text Available Mohamed A Hendaus,1 Fatima A Jomha,2 Ahmed H Alhammadi3 1Department of Pediatrics, Academic General Pediatrics Division, Weill-Cornell Medical College, Hamad Medical Corporation, Doha, Qatar; 2School of Pharmacy, Lebanese International University, Khiara, Lebanon; 3Department of Pediatrics, Academic General Pediatrics Division, Weill-Cornell Medical College, Hamad Medical Corporation, Doha, Qatar Abstract: Respiratory diseases are a very common source of morbidity and mortality among children. Health care providers often face a dilemma when encountering a febrile infant or child with respiratory tract infection. The reason expressed by many clinicians is the trouble to confirm whether the fever is caused by a virus or a bacterium. The aim of this review is to update the current evidence on the virus-induced bacterial infection. We present several clinical as well in vitro studies that support the correlation between virus and secondary bacterial infections. In addition, we discuss the pathophysiology and prevention modes of the virus–bacterium coexistence. A search of the PubMed and MEDLINE databases was carried out for published articles covering bacterial infections associated with respiratory viruses. This review should provide clinicians with a comprehensive idea of the range of bacterial and viral coinfections or secondary infections that could present with viral respiratory illness. Keywords: bacteria, infection, risk, virus

  4. Active Epstein-Barr virus infection after allogeneic stem cell transplantation : re-infection or reactivation?

    NARCIS (Netherlands)

    Meijer, E; Spijkers, S; Moschatsis, S; Boland, GJ; Thijsen, SFT; van Loon, AM; Verdonck, LF

    2005-01-01

    Recipients of allogeneic stem cell transplants (SCT) often show active Epstein-Barr virus (EBV) infection, which may progress to EBV-associated lymphoproliferative disorders. It is not known whether these EBV infections are true reactivations of the endogenous EBV strain or re-infections with an exo

  5. Research on viral dynamic models of hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    Lequan Min; Xisong Dong

    2004-01-01

    A mathematical model with cytotoxic cells of hepatitis B virus (HBV) infection is set up based on a basic model of virus dynamics without cytotoxic cells and experimental observation of anti-viral drug therapy for HBV infection patients. A quantitative analysis of dynamic behaviors shows that the model has three kinds of equilibrium points, which represent the patient's complete recovery without immune ability, complete recovery with immune ability, and HBV persistent infection at the end of the treatment with drug lamivudine, respectively. Our model may provide possible quantitative interpretations for the treatments of chronic HBV infections with the drug lamivudine, in particularly explain why the plasma virus of Nowak et al.'s patients turnover the original level after stopping the lamivudine treatment.

  6. Interferon Response in Hepatitis C Virus (HCV) Infection: Lessons from Cell Culture Systems of HCV Infection.

    Science.gov (United States)

    Sung, Pil Soo; Shin, Eui-Cheol; Yoon, Seung Kew

    2015-01-01

    Hepatitis C virus (HCV) is a positive-stranded RNA virus that infects approximately 130-170 million people worldwide. In 2005, the first HCV infection system in cell culture was established using clone JFH-1, which was isolated from a Japanese patient with fulminant HCV infection. JFH-1 replicates efficiently in hepatoma cells and infectious virion particles are released into the culture supernatant. The development of cell culture-derived HCV (HCVcc) systems has allowed us to understand how hosts respond to HCV infection and how HCV evades host responses. Although the mechanisms underlying the different outcomes of HCV infection are not fully understood, innate immune responses seem to have a critical impact on the outcome of HCV infection, as demonstrated by the prognostic value of IFN-λ gene polymorphisms among patients with chronic HCV infection. Herein, we review recent research on interferon response in HCV infection, particularly studies using HCVcc infection systems.

  7. Early Events in Chikungunya Virus Infection-From Virus Cell Binding to Membrane Fusion.

    Science.gov (United States)

    van Duijl-Richter, Mareike K S; Hoornweg, Tabitha E; Rodenhuis-Zybert, Izabela A; Smit, Jolanda M

    2015-07-07

    Chikungunya virus (CHIKV) is a rapidly emerging mosquito-borne alphavirus causing millions of infections in the tropical and subtropical regions of the world. CHIKV infection often leads to an acute self-limited febrile illness with debilitating myalgia and arthralgia. A potential long-term complication of CHIKV infection is severe joint pain, which can last for months to years. There are no vaccines or specific therapeutics available to prevent or treat infection. This review describes the critical steps in CHIKV cell entry. We summarize the latest studies on the virus-cell tropism, virus-receptor binding, internalization, membrane fusion and review the molecules and compounds that have been described to interfere with virus cell entry. The aim of the review is to give the reader a state-of-the-art overview on CHIKV cell entry and to provide an outlook on potential new avenues in CHIKV research.

  8. Influenza and respiratory syncytial virus infections in British Hajj pilgrims

    OpenAIRE

    Rashid, H.; Shafi, S; Booy, R; Bashir, H El; K Ali; Zambon, MC; Memish, ZA; Ellis, J; Coen, PG; Haworth, E

    2011-01-01

    Viral respiratory infections including influenza and respiratory syncytial virus (RSV) have been reported during the Hajj among international pilgrims. To help establish the burden of these infections at the Hajj, we set up a study to confirm these diagnoses in symptomatic British pilgrims who attended the 2005 Hajj. UK pilgrims with symptoms of upper respiratory tract infection (URTI) were invited to participate; after taking medical history, nasal swabs were collected for point-of-care test...

  9. Influenza and respiratory syncytial virus infections in British Hajj pilgrims

    OpenAIRE

    Booy, R; K Ali; El Bashir, H; MC Zambon; Ellis, J; Memish ZA; PG Coen; Haworth, E; Shafi, S; Rashid, H.

    2008-01-01

    Viral respiratory infections including influenza and respiratory syncytial virus (RSV) have been reported during the Hajj among international pilgrims. To help establish the burden of these infections at the Hajj, we set up a study to confirm these diagnoses in symptomatic British pilgrims who attended the 2005 Hajj. UK pilgrims with symptoms of upper respiratory tract infection (URTI) were invited to participate; after taking medical history, nasal swabs were collected for point-of-care test...

  10. New perspectives in occult hepatitis C virus infection

    OpenAIRE

    Carreño, Vicente; Bartolomé, Javier; Castillo, Inmaculada; Quiroga, Juan Antonio

    2012-01-01

    Occult hepatitis C virus (HCV) infection, defined as the presence of HCV RNA in liver and in peripheral blood mononuclear cells (PBMCs) in the absence of detectable viral RNA in serum by standard assays, can be found in anti-HCV positive patients with normal serum levels of liver enzymes and in anti-HCV negative patients with persistently elevated liver enzymes of unknown etiology. Occult HCV infection is distributed worldwide and all HCV genotypes seem to be involved in this infection. Occul...

  11. Innate immune recognition of respiratory syncytial virus infection

    OpenAIRE

    Kim, Tae Hoon; Lee, Heung Kyu

    2014-01-01

    Respiratory syncytial virus (RSV) is the leading cause of respiratory infection in infants and young children. Severe clinical manifestation of RSV infection is a bronchiolitis, which is common in infants under six months of age. Recently, RSV has been recognized as an important cause of respiratory infection in older populations with cardiovascular morbidity or immunocompromised patients. However, neither a vaccine nor an effective antiviral therapy is currently available. Moreover, the inte...

  12. Emerging Zika virus infection: What should we know?

    Directory of Open Access Journals (Sweden)

    Viroj Wiwanitkit

    2016-07-01

    Full Text Available Zika virus infection is a new emerging viral disease that becomes the present public health threat. At present, this infection can be seen in several countries. The clinical presentation of this infection is a dengue-like illness. Nevertheless, the new information shows that the disease can be sexually transmitted and transplacentally transmitted. In addition, the recent evidence from the recent epidemic in South America shows that the infection in pregnancy can cause neonatal neurological defect. In this short review, the author summarizes and presents interesting data on clinical features of this new emerging infection.

  13. Emerging Zika virus infection:What should we know?

    Institute of Scientific and Technical Information of China (English)

    Viroj Wiwanitkit

    2016-01-01

    Zika virus infection is a new emerging viral disease that becomes the present public health threat. At present, this infection can be seen in several countries. The clinical presentation of this infection is a dengue-like illness. Nevertheless, the new information shows that the disease can be sexually transmitted and transplacentally transmitted. In addition, the recent evidence from the recent epidemic in South America shows that the infection in pregnancy can cause neonatal neurological defect. In this short review, the author summarizes and presents interesting data on clinical features of this new emerging infection.

  14. Critical Role of Airway Macrophages in Modulating Disease Severity during Influenza Virus Infection of Mice ▿

    OpenAIRE

    Tate, M.D.; Pickett, D L; Rooijen, van, J.; Brooks, A G; Reading, P C

    2010-01-01

    Airway macrophages provide a first line of host defense against a range of airborne pathogens, including influenza virus. In this study, we show that influenza viruses differ markedly in their abilities to infect murine macrophages in vitro and that infection of macrophages is nonproductive and no infectious virus is released. Virus strain BJx109 (H3N2) infected macrophages with high efficiency and was associated with mild disease following intranasal infection of mice. In contrast, virus str...

  15. Virus and host factors affecting the clinical outcome of Bluetongue Virus infection

    NARCIS (Netherlands)

    Caporale, M.; Gialleonorado, L.; Janowicz, A.; Wilkie, G.; Shaw, A.; Savini, G.; Rijn, van P.A.; Mertens, P.; Ventura, M.; Palmarini, M.

    2014-01-01

    Bluetongue is a major infectious disease of ruminants caused by bluetongue virus (BTV), an arbovirus transmitted by Culicoides. Here, we assessed virus and host factors influencing the clinical outcome of BTV infection using a single experimental framework. We investigated how mammalian host species

  16. Why Zika virus infection has become a public health concern?

    Science.gov (United States)

    Chen, Hui-Lan; Tang, Ren-Bin

    2016-04-01

    Prior to 2015, Zika Virus (ZIKV) outbreaks had occurred in areas of Africa, Southeast Asia, and the Pacific Islands. Although a causal relationship between Zika infection during pregnancy and microcephaly is strongly suspected, such a connection has not yet been scientifically proven. In May 2015, the outbreak of ZIKV infection in Brazil led to reports of syndrome and pregnant women giving birth to babies with birth defects and poor pregnancy outcomes; the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed ZIKV infection in Brazil. Currently, ZIKV outbreaks are ongoing and it will be difficult to predict how the virus will spread over time. ZIKV is transmitted to humans primarily through the bite of infected mosquitos, Aedes aegypti and Aedes albopictus. These mosquitoes are the principle vectors of dengue, and ZIKV disease generally is reported to include symptoms associated with acute febrile illnesses that clinically resembles dengue fever. The laboratory diagnosis can be performed by using reverse-transcriptase polymerase chain reaction (RT-PCR) on serum, viral nucleic acid and virus-specific immunoglobulin M. There is currently no vaccine and antiviral treatment available for ZIKV infection, and the only way to prevent congenital ZIKV infection is to prevent maternal infection. In February 2016, the Taiwan Centers for Disease Control (Taiwan CDC) activated ZIKV as a Category V Notifiable Infectious Disease similar to Ebola virus disease and MERS. PMID:27052792

  17. Vaccination of chimpanzees against infection by the hepatitis C virus.

    Science.gov (United States)

    Choo, Q L; Kuo, G; Ralston, R; Weiner, A; Chien, D; Van Nest, G; Han, J; Berger, K; Thudium, K; Kuo, C

    1994-02-15

    A high incidence of community-acquired hepatitis C virus infection that can lead to the progressive development of chronic active hepatitis, liver cirrhosis, and primary hepatocellular carcinoma occurs throughout the world. A vaccine to control the spread of this agent that represents a major cause of chronic liver disease is therefore needed. Seven chimpanzees (Pan troglodytes) have been immunized with both putative envelope glycoproteins [E1 (gp33) and E2 (gp72)] that were copurified from HeLa cells infected with a recombinant vaccinia virus expression vector. Despite the induction of a weak humoral immune response to these viral glycoproteins in experimentally infected chimpanzees, a strong humoral immune response was obtained in all vaccines. The five highest responders showed complete protection against an i.v. challenge with homologous hepatitis C virus 1. The remaining two vaccines became infected, but both infection and disease may have been ameliorated in comparison with four similarly challenged control chimpanzees, all of which developed acute hepatitis and chronic infections. These results provide considerable encouragement for the eventual control of hepatitis C virus infection by vaccination. PMID:7509068

  18. Why Zika virus infection has become a public health concern?

    Science.gov (United States)

    Chen, Hui-Lan; Tang, Ren-Bin

    2016-04-01

    Prior to 2015, Zika Virus (ZIKV) outbreaks had occurred in areas of Africa, Southeast Asia, and the Pacific Islands. Although a causal relationship between Zika infection during pregnancy and microcephaly is strongly suspected, such a connection has not yet been scientifically proven. In May 2015, the outbreak of ZIKV infection in Brazil led to reports of syndrome and pregnant women giving birth to babies with birth defects and poor pregnancy outcomes; the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed ZIKV infection in Brazil. Currently, ZIKV outbreaks are ongoing and it will be difficult to predict how the virus will spread over time. ZIKV is transmitted to humans primarily through the bite of infected mosquitos, Aedes aegypti and Aedes albopictus. These mosquitoes are the principle vectors of dengue, and ZIKV disease generally is reported to include symptoms associated with acute febrile illnesses that clinically resembles dengue fever. The laboratory diagnosis can be performed by using reverse-transcriptase polymerase chain reaction (RT-PCR) on serum, viral nucleic acid and virus-specific immunoglobulin M. There is currently no vaccine and antiviral treatment available for ZIKV infection, and the only way to prevent congenital ZIKV infection is to prevent maternal infection. In February 2016, the Taiwan Centers for Disease Control (Taiwan CDC) activated ZIKV as a Category V Notifiable Infectious Disease similar to Ebola virus disease and MERS.

  19. Secondary dengue virus type 4 infections in Vietnam.

    Science.gov (United States)

    Buchy, Philippe; Vo, Van Luong; Bui, Khanh Toan; Trinh, Thi Xuan Mai; Glaziou, Philippe; Le, Thi Thu Ha; Le, Viet Lo; Bui, Trong Chien

    2005-01-01

    This study was designated to describe clinical and biological features of patients with a suspected diagnosis of dengue fever/dengue hemorrhagic fever during an outbreak in Central Vietnam. One hundred and twenty-five consecutive patients hospitalized at Khanh Hoa and Binh Thuan Provincial hospitals between November 2001 and January 2002 with a diagnosis of suspected dengue infection were included in the present study. Viruses were isolated in C6/36 and VERO E6 cell cultures or detected by RT-PCR. A hemagglutination-inhibition test (HI) was done on each paired sera using dengue antigens type 1-4, Japanese encephalitis (JE) virus antigen, Chickungunya virus antigen and Sindbis virus antigen. Anti-dengue and anti-JE virus IgM were measured by a capture enzyme-linked immunosorbent assay (MAC-ELISA). Anti-dengue and anti-JE virus IgG were measured by an ELISA test. Dengue viruses were isolated in cell culture and/or detected by RT-PCR in 20.8% of blood samples. DEN-4 and DEN-2 serotypes were found in 18.4% and 2.4% of the patients, respectively. A total of 86.4% of individuals had a diagnosis of acute dengue fever by using the HI test and/or dengue virus-specific IgM capture-ELISA and/or virus isolation and/or RT-PCR. The prevalence of primary and secondary acute dengue infection was 4% and 78.4%, respectively. Anti-dengue IgG ELISA test was positive in 88.8% of the patients. In 5 cases (4%), Japanese encephalitis virus infection was positive by serology but the cell culture was negative. No Chickungunya virus or Sindbis virus infection was detected by the HI test. In patients with acute dengue virus infection, the most common presenting symptom was headache, followed by conjunctivitis, petechial rash, muscle and joint pain, nausea and abdominal pain. Four percent of hospitalized patients were classified as dengue hemorrhagic fever. The clinical presentation and blood cell counts were similar between patients hospitalized with acute dengue fever and patients with other

  20. Metabolic stress in infected cells may represent a therapeutic target for human immunodeficiency virus infection.

    Science.gov (United States)

    Alonso-Villaverde, Carlos; Menéndez, Javier A; Joven, Jorge

    2013-07-01

    Worldwide, there are thousands of new cases of human immunodeficiency virus-1 (HIV-1) infection per day. The effectiveness of current combination antiretroviral therapy (ART) is relative; to prioritize finding vaccines and/or cure-oriented initiatives should be reinforced because there is little room, if any, for procrastination. Basic and clinical findings on HIV-1 reservoirs suggest that disruption of virus latency is feasible. Because the goal is curing HIV-1 infection, we should be aware that the challenge is to eradicate the viruses of every single infected cell and consequently acting upon virus latency is necessary but not sufficient. The large majority of the virus reservoir, CD4(+) T lymphocytes, is readily accessible but other minor reservoirs, where ART does not diffuse, require innovative strategies. The situation closely resembles that currently faced in the treatment of cancer. Exploiting the fact that histone deacetylase inhibitors, mainly vorinostat, may disrupt the latency of HIV-1, we propose to supplement this effect with a programmed interference in the metabolic stress of infected cells. Metformin and chloroquine are cheap and accessible modulators of pro-survival mechanisms to which viruses are constantly confronted to generate alternative energy sources and maximize virus production. Metformin restrains the use of the usurped cellular biosynthetic machinery by viral genes and chloroquine contributes to death of infected cells. We suggest that the combination of vorinostat, chloroquine and metformin should be combined with ART to pursue viral eradication in infected cells. PMID:23639282

  1. Characterisation of three novel giant viruses reveals huge diversity among viruses infecting Prymnesiales (Haptophyta).

    Science.gov (United States)

    Johannessen, Torill Vik; Bratbak, Gunnar; Larsen, Aud; Ogata, Hiroyuki; Egge, Elianne S; Edvardsen, Bente; Eikrem, Wenche; Sandaa, Ruth-Anne

    2015-02-01

    We have isolated three novel lytic dsDNA-viruses from Raunefjorden (Norway) that are putative members of the Mimiviridae family, namely Haptolina ericina virus RF02 (HeV RF02), Prymnesium kappa virus RF01 (PkV RF01), and Prymnesium kappa virus RF02 (PkV RF02). Each of the novel haptophyte viruses challenges the common conceptions of algal viruses with respect to host range, phylogenetic affiliation and size. PkV RF01 has a capsid of ~310 nm and is the largest algal virus particle ever reported while PkV RF01 and HeV RF02 were able to infect different species, even belonging to different genera. Moreover, PkV RF01 and HeV RF02 infected the same hosts, but phylogenetic analysis placed them in different groups. Our results reveal large variation among viruses infecting closely related microalgae, and challenge the common conception that algal viruses have narrow host range, and phylogeny reflecting their host affiliation. PMID:25546253

  2. Up-to-date knowledge of West Nile virus infection

    Directory of Open Access Journals (Sweden)

    Hrnjaković-Cvjetković Ivana

    2009-01-01

    Full Text Available Virus West Nile virus is a single-stranded RNA virus of the family Flaviviridae, genus Flavivirus. Epidemiology West Nile virus is maintained in the cycle involving culicine mosquitoes and birds .Humans typically acquire West Nile infection through a bite from infected adult mosquito. Person to person transmission can occur through organ transplantation, blood and blood product transfusions, transplacentally and via brest milk. Human cases of West Nile infections were recorded in Africa, Israel, Russia, India, Pakistan. In Romania in 1996 West Nile fever occurred with hundreds of neurologic cases and 17 fatalities. First human cases in the United States were in New York City where 59 persons were infected and had fever, meningitis, encephalitis and flaccid paralysis. Clinical manifestation Most human cases are asymptomatic. The majority of symptomatic patients have a self limited febrile illness. Fatigue, nausea, vomiting, eye pain, headache, myalgias, artralgias, lymphadenopathy and rash are common complaints. Less than 1% of all infected persons develop more severe neurologic illness including meningitis, encefalitis and flaccid paralysis. Laboratory diagnosis Diagnosis of West Nile virus infection is based on serologic testing, isolation of virus from patient samples and detection of viral antigen or viral genom. ELISA test and indirect immunofluorescenceassay are used for detecting IgM and IgG antibodies in serum and cerebrospinal fluid. Treatment In vitro studies have suggested that ribavirin and interferon alfa -2b may be useful in the treatment of West Nile virus disease. Prevention The most important measures are mosquito control program and personal protective measures. .

  3. Deep Sequencing Analysis of Apple Infecting Viruses in Korea

    Science.gov (United States)

    Cho, In-Sook; Igori, Davaajargal; Lim, Seungmo; Choi, Gug-Seoun; Hammond, John; Lim, Hyoun-Sub; Moon, Jae Sun

    2016-01-01

    Deep sequencing has generated 52 contigs derived from five viruses; Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV), Apple stem pitting virus (ASPV), Apple green crinkle associated virus (AGCaV), and Apricot latent virus (ApLV) were identified from eight apple samples showing small leaves and/or growth retardation. Nucleotide (nt) sequence identity of the assembled contigs was from 68% to 99% compared to the reference sequences of the five respective viral genomes. Sequences of ASPV and ASGV were the most abundantly represented by the 52 contigs assembled. The presence of the five viruses in the samples was confirmed by RT-PCR using specific primers based on the sequences of each assembled contig. All five viruses were detected in three of the samples, whereas all samples had mixed infections with at least two viruses. The most frequently detected virus was ASPV, followed by ASGV, ApLV, ACLSV, and AGCaV which were withal found in mixed infections in the tested samples. AGCaV was identified in assembled contigs ID 1012480 and 93549, which showed 82% and 78% nt sequence identity with ORF1 of AGCaV isolate Aurora-1. ApLV was identified in three assembled contigs, ID 65587, 1802365, and 116777, which showed 77%, 78%, and 76% nt sequence identity respectively with ORF1 of ApLV isolate LA2. Deep sequencing assay was shown to be a valuable and powerful tool for detection and identification of known and unknown virome in infected apple trees, here identifying ApLV and AGCaV in commercial orchards in Korea for the first time.

  4. Effects of interferons on hepatitis C virus infection

    Directory of Open Access Journals (Sweden)

    Bojić Ivanko

    2006-01-01

    Full Text Available Introduction. The consequences of hepatitis C virus infections (chronic hepatitis, liver cirrhosis and hepatocellular carcinoma are one of the major problems in clinical medicine. The persistence of infection in spite of high specific antibody titre suggests that the virus has the ability to "escape" the immunological response. Interferon therapy. Interferons are important components of the early host response to infection. They have antiviral, antiproliferative, and immunomodulatory activities. Many viruses have developed the ability to "annul" or alleviate the action of interferon by preventing its synthesis or by interfering with signaling pathways in the cells. During acute infection some of the non-structural proteins of HCV block regulatory factors that are responsible for the synthesis of endogenous infection. Within a cell, interferon induces a number of genes to produce proteins that prevent virus replication. Among them, the most important are RNA-dependent protein kinase and the eukaryotic initiation factor. However, viral proteins, especially viral envelope proteins and nonstructural protein 5A, prevent their phosphorylation and activation which enhance virus replication. These are the facts that have to be considered when using IFN in chronic hepatitis C patients. .

  5. Bordetella pertussis infection exacerbates influenza virus infection through pertussis toxin-mediated suppression of innate immunity.

    Directory of Open Access Journals (Sweden)

    Victor I Ayala

    Full Text Available Pertussis (whooping cough is frequently complicated by concomitant infections with respiratory viruses. Here we report the effect of Bordetella pertussis infection on subsequent influenza virus (PR8 infection in mouse models and the role of pertussis toxin (PT in this effect. BALB/c mice infected with a wild-type strain of B. pertussis (WT and subsequently (up to 14 days later infected with PR8 had significantly increased pulmonary viral titers, lung pathology and mortality compared to mice similarly infected with a PT-deficient mutant strain (ΔPT and PR8. Substitution of WT infection by intranasal treatment with purified active PT was sufficient to replicate the exacerbating effects on PR8 infection in BALB/c and C57/BL6 mice, but the effects of PT were lost when toxin was administered 24 h after virus inoculation. PT had no effect on virus titers in primary cultures of murine tracheal epithelial cells (mTECs in vitro, suggesting the toxin targets an early immune response to increase viral titers in the mouse model. However, type I interferon responses were not affected by PT. Whole genome microarray analysis of gene expression in lung tissue from PT-treated and control PR8-infected mice at 12 and 36 h post-virus inoculation revealed that PT treatment suppressed numerous genes associated with communication between innate and adaptive immune responses. In mice depleted of alveolar macrophages, increase of pulmonary viral titers by PT treatment was lost. PT also suppressed levels of IL-1β, IL-12, IFN-γ, IL-6, KC, MCP-1 and TNF-α in the airways after PR8 infection. Furthermore PT treatment inhibited early recruitment of neutrophils and NK cells to the airways. Together these findings demonstrate that infection with B. pertussis through PT activity predisposes the host to exacerbated influenza infection by countering protective innate immune responses that control virus titers.

  6. The virus-encoded chemokine vMIP-II inhibits virus-induced Tc1-driven inflammation

    DEFF Research Database (Denmark)

    Lindow, Morten; Nansen, Anneline; Bartholdy, Christina;

    2003-01-01

    virus-induced T-cell-mediated inflammation. This was done by use of the well-established model system murine lymphocytic choriomeningitis virus infection. Mice were infected in the footpad, and the induced CD8(+) T-cell-dependent inflammation was evaluated in mice subjected to treatment with vMIP-II. We...... found that inflammation was markedly inhibited in mice treated during the efferent phase of the antiviral immune response. In vitro studies revealed that vMIP-II inhibited chemokine-induced migration of activated CD8(+) T cells, but not T-cell-target cell contact, granule exocytosis, or cytokine release....... Consistent with these in vitro findings treatment with vMIP-II inhibited the adoptive transfer of a virus-specific delayed-type hypersensitivity response in vivo, but only when antigen-primed donor cells were transferred via the intravenous route and required to migrate actively, not when the cells were...

  7. Pseudorabies virus infection alters neuronal activity and connectivity in vitro.

    Directory of Open Access Journals (Sweden)

    Kelly M McCarthy

    2009-10-01

    Full Text Available Alpha-herpesviruses, including human herpes simplex virus 1 & 2, varicella zoster virus and the swine pseudorabies virus (PRV, infect the peripheral nervous system of their hosts. Symptoms of infection often include itching, numbness, or pain indicative of altered neurological function. To determine if there is an in vitro electrophysiological correlate to these characteristic in vivo symptoms, we infected cultured rat sympathetic neurons with well-characterized strains of PRV known to produce virulent or attenuated symptoms in animals. Whole-cell patch clamp recordings were made at various times after infection. By 8 hours of infection with virulent PRV, action potential (AP firing rates increased substantially and were accompanied by hyperpolarized resting membrane potentials and spikelet-like events. Coincident with the increase in AP firing rate, adjacent neurons exhibited coupled firing events, first with AP-spikelets and later with near identical resting membrane potentials and AP firing. Small fusion pores between adjacent cell bodies formed early after infection as demonstrated by transfer of the low molecular weight dye, Lucifer Yellow. Later, larger pores formed as demonstrated by transfer of high molecular weight Texas red-dextran conjugates between infected cells. Further evidence for viral-induced fusion pores was obtained by infecting neurons with a viral mutant defective for glycoprotein B, a component of the viral membrane fusion complex. These infected neurons were essentially identical to mock infected neurons: no increased AP firing, no spikelet-like events, and no electrical or dye transfer. Infection with PRV Bartha, an attenuated circuit-tracing strain delayed, but did not eliminate the increased neuronal activity and coupling events. We suggest that formation of fusion pores between infected neurons results in electrical coupling and elevated firing rates, and that these processes may contribute to the altered neural

  8. Innate immune targets of hepatitis B virus infection.

    Science.gov (United States)

    Zou, Zhi-Qiang; Wang, Li; Wang, Kai; Yu, Ji-Guang

    2016-06-18

    Approximately 400 million people are chronically infected with hepatitis B virus (HBV) globally despite the widespread immunization of HBV vaccine and the development of antiviral therapies. The immunopathogenesis of HBV infection is initiated and driven by complexed interactions between the host immune system and the virus. Host immune responses to viral particles and proteins are regarded as the main determinants of viral clearance or persistent infection and hepatocyte injury. Innate immune system is the first defending line of host preventing from virus invasion. It is acknowledged that HBV has developed active tactics to escape innate immune recognition or actively interfere with innate immune signaling pathways and induce immunosuppression, which favor their replication. HBV reduces the expression of pattern-recognition receptors in the innate immune cells in humans. Also, HBV may interrupt different parts of antiviral signaling pathways, leading to the reduced production of antiviral cytokines such as interferons that contribute to HBV immunopathogenesis. A full comprehension of the mechanisms as to how HBV inactivates various elements of the innate immune response to initiate and maintain a persistent infection can be helpful in designing new immunotherapeutic methods for preventing and eradicating the virus. In this review, we aimed to summarize different branches the innate immune targeted by HBV infection. The review paper provides evidence that multiple components of immune responses should be activated in combination with antiviral therapy to disrupt the tolerance to HBV for eliminating HBV infection. PMID:27330680

  9. Zika virus infections: An overview of current scenario.

    Science.gov (United States)

    Dasti, Javid Iqbal

    2016-07-01

    Zika virus (ZIKV) was discovered more than half a century ago, recently it has gained unprecedented attention by the global health community. Until 2007, only 14 cases of human ZIKV infections were reported around the globe, while during the current outbreak, estimated cases mounted to approximately 1.5 million in Brazil alone, the virus was disseminated to wider South-American territories and travel-associated ZIKV infections were reported in USA, Europe and recently in China. ZIKV infections remain asymptomatic in approximately 80% of the individuals, and no anti-viral treatments were recommended. Yet, neurological complications associated with the infections, such as infant microcephaly and Guillain-Barré syndrome are major cause of the concern. Although, based on small numbers of cases, existing evidence strongly supports an exclusive link of viral infection and observed neurological complications. However, much work remains to assign exact numbers of complications caused by ZIKV. Regarding its structural attributes ZIKV shows remarkable resemblance with dengue virus and West-Nile virus. Despite, genomes of different ZIKV strains have already been decoded; role of the viral components in infection process and particularly pathogenesis of the disease remain widely unclear. In vulnerable areas, most viable strategy to ensure public health safety is vector control and enhanced public awareness about the transmission of the disease.

  10. Zika virus infections: An overview of current scenario.

    Science.gov (United States)

    Dasti, Javid Iqbal

    2016-07-01

    Zika virus (ZIKV) was discovered more than half a century ago, recently it has gained unprecedented attention by the global health community. Until 2007, only 14 cases of human ZIKV infections were reported around the globe, while during the current outbreak, estimated cases mounted to approximately 1.5 million in Brazil alone, the virus was disseminated to wider South-American territories and travel-associated ZIKV infections were reported in USA, Europe and recently in China. ZIKV infections remain asymptomatic in approximately 80% of the individuals, and no anti-viral treatments were recommended. Yet, neurological complications associated with the infections, such as infant microcephaly and Guillain-Barré syndrome are major cause of the concern. Although, based on small numbers of cases, existing evidence strongly supports an exclusive link of viral infection and observed neurological complications. However, much work remains to assign exact numbers of complications caused by ZIKV. Regarding its structural attributes ZIKV shows remarkable resemblance with dengue virus and West-Nile virus. Despite, genomes of different ZIKV strains have already been decoded; role of the viral components in infection process and particularly pathogenesis of the disease remain widely unclear. In vulnerable areas, most viable strategy to ensure public health safety is vector control and enhanced public awareness about the transmission of the disease. PMID:27393087

  11. CD4+ T cell responses in hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    Nasser Semmo; Paul Klenerman

    2007-01-01

    Hepatitis C virus (HCV) infection is a major cause of liver damage, with virus-induced end-stage disease such as liver cirrhosis and hepatocellular carcinoma resulting in a high rate of morbidity and mortality worldwide. Evidence that CD4+ T cell responses to HCV play an important role in the outcome of acute infection has been shown in several studies. However, the mechanisms behind viral persistence and the failure of CD4+ T cell responses to contain virus are poorly understood. During chronic HCV infection, HCV-specific CD4+ T cell responses are relatively weak or absent whereas in resolved infection these responses are vigorous and multispecific. Persons with a T-helper type Ⅰ profile, which promotes cellular effector mechanisms are thought to be more likely to experience viral clearance, but the overall role of these cells in the immunopathogenesis of chronic liver disease is not known. To define this, much more data is required on the function and specificity of virus-specific CD4+ T cells,especially in the early phases of acute disease and in the liver during chronic infection. The role and possible mechanisms of action of CD4+ T cell responses in determining the outcome of acute and chronic HCV infection will be discussed in this review.

  12. Schmallenberg virus experimental infection of sheep

    DEFF Research Database (Denmark)

    Wernike, Kerstin; Hoffmann, Bernd; Bréard, Emmanuel;

    2013-01-01

    Since late 2011, a novel orthobunyavirus, named Schmallenberg virus (SBV), has been implicated in many cases of severely malformed bovine and ovine offspring in Europe. In adult cattle, SBV is known to cause a mild transient disease; clinical signs include short febrile episodes, decreased milk...... production and diarrhoea for a few days. However, the knowledge about clinical signs and pathogenesis in adult sheep is limited.In the present study, adult sheep of European domestic breeds were inoculated with SBV either as cell culture grown virus or as virus with no history of passage in cell cultures...... 3–5 days by real-time RT-PCR. In total, 13 out of 30 inoculated sheep became RNAemic, with the highest viral load in animals inoculated with virus from low cell culture passaged or the animal passaged material. Contact animals remained negative throughout the study. One RNAemic sheep showed...

  13. A Virus-type Specific Serological Diagnosis of Flavivirus Infection Using Virus-like Particles

    Institute of Scientific and Technical Information of China (English)

    Min QING; Zhi-ming YUAN; Pei-Yong Shi

    2009-01-01

    Many flaviviruses are emerging and reemerging pathogens, such as West Nile virus (WNV), dengue virus (DENV), yellow fever virus (YFV), and Japanese encephalitis virus. Serological assay is the dominant method for diagnosis of flavivirus infections in human. Because antibodies generated during flavivirus infections cross-react with other flavivirus members, plaque reduction neutralization test (PRNT) is the only available assay to determine the infecting flavivirus type.Since PRNT requires culturing raw viruses, it must be performed in biosafety level-3 or level-4 containment for many flaviviruses, and takes more than ten days to complete. To overcome these problems, we have developed flavivirus viral-like particles (VLPs) that could be used to replace raw viruses in the neutralization assay. The VLPs were prepared by trans packaging a luciferase-reporting replicon with viral structural proteins. This novel assay involves three simple steps: (ⅰ) VLPs from a panel of flaviviruses are incubated with flavivirus-infected sera at 37℃ for 1 h; (ⅱ)the neutralized VLPs are used to infect Vero cells; and (ⅲ) the infected cells are measured for luciferase activities at 22 h post-infection. The virus type whose VLP is most efficiently neutralized by the serum specimen (as quantified by the luciferase activities) is the etiologic agent. As a proof-of-concept, we show that a WNV-infected mouse serum neutralized the WNV VLP more efficiently and selectively than the DENV and YFV VLPs. Our results demonstrate that the VLP neutralization assay maintains the "gold standard" of the classic PRNT; importantly, it shortens the assay time from >10 days to <1 day, and can be performed in biosafety level-2 facility.

  14. Avian Influenza: Mixed Infections and Missing Viruses

    OpenAIRE

    Wentworth, David E.; Dugan, Vivien G.; Xudong Lin; Seth Schobel; Magdalena Plancarte; Kelly, Terra R.; Lindsay, LeAnn L.; Boyce, Walter M.

    2013-01-01

    A high prevalence and diversity of avian influenza (AI) viruses were detected in a population of wild mallards sampled during summer 2011 in California, providing an opportunity to compare results obtained before and after virus culture. We tested cloacal swab samples prior to culture by matrix real-time PCR, and by amplifying and sequencing a 640bp portion of the hemagglutinin (HA) gene. Each sample was also inoculated into embryonated chicken eggs, and full genome sequences were determined ...

  15. Reduced incorporation of the influenza B virus BM2 protein in virus particles decreases infectivity

    International Nuclear Information System (INIS)

    BM2 is the fourth integral membrane protein encoded by the influenza B virus genome. It is synthesized late in infection and transported to the plasma membrane from where it is subsequently incorporated into progeny virus particles. It has recently been reported that BM2 has ion channel activity and may be the functional homologue of the influenza A virus M2 protein acting as an ion channel involved in viral entry. Using a reverse genetic approach it was not possible to recover virus which lacked BM2. A recombinant influenza B virus was generated in which the BM2 AUG initiation codon was mutated to GUG. This decreased the efficiency of translation of BM2 protein such that progeny virions contained only 1/8 the amount of BM2 seen in wild-type virus. The reduction in BM2 incorporation resulted in a reduction in infectivity although there was no concomitant decrease in the numbers of virions released from the infected cells. These data imply that the incorporation of sufficient BM2 protein into influenza B virions is required for infectivity of the virus particles

  16. Vaccinia Virus Infections in a Martial Arts Gym

    Centers for Disease Control (CDC) Podcasts

    2011-04-04

    This podcast discusses an outbreak of vaccinia virus in Maryland in 2008. Christine Hughes, a health scientist with the Poxvirus and Rabies Branch at CDC, and co-author of a paper in the April 2011 issue of CDC's journal, discusses vaccinia virus infections in a martial arts gym.  Created: 4/4/2011 by National Center for Emerging Zoonotic and Infectious Diseases (NCEZID).   Date Released: 4/5/2011.

  17. Current Approaches for Diagnosis of Influenza Virus Infections in Humans

    OpenAIRE

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-01-01

    Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000–50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemi...

  18. Cohabitation reaction-diffusion model for virus focal infections

    Science.gov (United States)

    Amor, Daniel R.; Fort, Joaquim

    2014-12-01

    The propagation of virus infection fronts has been typically modeled using a set of classical (noncohabitation) reaction-diffusion equations for interacting species. However, for some single-species systems it has been recently shown that noncohabitation reaction-diffusion equations may lead to unrealistic descriptions. We argue that previous virus infection models also have this limitation, because they assume that a virion can simultaneously reproduce inside a cell and diffuse away from it. For this reason, we build a several-species cohabitation model that does not have this limitation. Furthermore, we perform a sensitivity analysis for the most relevant parameters of the model, and we compare the predicted infection speed with observed data for two different strains of the T7 virus.

  19. Background review for diagnostic test development for Zika virus infection

    Science.gov (United States)

    Charrel, Rémi N; Leparc-Goffart, Isabelle; Pas, Suzan; de Lamballerie, Xavier; Koopmans, Marion; Reusken, Chantal

    2016-01-01

    Abstract Objective To review the state of knowledge about diagnostic testing for Zika virus infection and identify areas of research needed to address the current gaps in knowledge. Methods We made a non-systematic review of the published literature about Zika virus and supplemented this with information from commercial diagnostic test kits and personal communications with researchers in European preparedness networks. The review covered current knowledge about the geographical spread, pathogen characteristics, life cycle and infection kinetics of the virus. The available molecular and serological tests and biosafety issues are described and discussed in the context of the current outbreak strain. Findings We identified the following areas of research to address current knowledge gaps: (i) an urgent assessment of the laboratory capacity and capability of countries to detect Zika virus; (ii) rapid and extensive field validation of the available molecular and serological tests in areas with and without Zika virus transmission, with a focus on pregnant women; (iii) monitoring the genomic diversity of circulating Zika virus strains; (iv) prospective studies into the virus infection kinetics, focusing on diagnostic sampling (specimen types, combinations and timings); and (v) developing external quality assessments for molecular and serological testing, including differential diagnosis for similar viruses and symptom clusters. The availability of reagents for diagnostic development (virus strains and antigens, quantified viral ribonucleic acid) needs to be facilitated. Conclusion An international laboratory response is needed, including preparation of protocols for prospective studies to address the most pressing information needs. PMID:27516635

  20. THE POSSIBLE COLLISIONS IN VIRUS INFECTION IMMUNODIAGNOSTICS AND VACCINATION

    Directory of Open Access Journals (Sweden)

    E. P. Kharchenko

    2016-01-01

    Full Text Available Antibodies (Ab, especially natural, display multiple specificity not only due to intrinsic conformational dynamics. With computational analysis the distribution of identical and homologous peptides has been studied in surface proteins from RNA and DNA viruses of widely distributed infections. It was established that each virus protein shared the fragments homologous to other virus proteins that allowed to propose the existence of the peptide continuum of the protein relationship (PCPR. Possible manifestations of PCPR are multiple reactivity and autoreactivity in Ab and therefore it is not possible to consider the immune methods of virus identification as high reliable because of crossing interactions. The PCPR excludes the existence of 100% specificity in immune tests for virus identification. Immunodiagnostic collisions may occur either in identification of virus itself or identification of Ab to viruses. Also PCPR may be responsible for heterologous immunity and consequently the infection associated with severe pathology. The comparative analysis of peptide relationship of H1N1 influenza virus nucleoprotein and human proteins found out, beyond early described its common motif with human hypocretin receptor 2, peptides homologous to those in melanotonin and glutamate receptors and three ion channels. It allows to propose that the sleep disorder narcolepsy associated with Pandemrix vaccination (an adjuvanted, influenza pandemic vaccine and also with infection by influenza virus during the 2009 A(H1N1 influenza pandemic may be determined not only by Ab to the peptide motif common to influenza nucleoprotein and hypocretin receptor but also Ab to melanotonin and glutamate receptors and ion channels. Decreasing and even avoiding risks of complications from vaccination may be feasible by means of a computer analysis of vaccine proteins for the occurrence of epitopes homologous to the human protein those and particularly by an analysis of Ab profiles

  1. Marburg virus infection detected in a common African bat.

    Directory of Open Access Journals (Sweden)

    Jonathan S Towner

    Full Text Available Marburg and Ebola viruses can cause large hemorrhagic fever (HF outbreaks with high case fatality (80-90% in human and great apes. Identification of the natural reservoir of these viruses is one of the most important topics in this field and a fundamental key to understanding their natural history. Despite the discovery of this virus family almost 40 years ago, the search for the natural reservoir of these lethal pathogens remains an enigma despite numerous ecological studies. Here, we report the discovery of Marburg virus in a common species of fruit bat (Rousettus aegyptiacus in Gabon as shown by finding virus-specific RNA and IgG antibody in individual bats. These Marburg virus positive bats represent the first naturally infected non-primate animals identified. Furthermore, this is the first report of Marburg virus being present in this area of Africa, thus extending the known range of the virus. These data imply that more areas are at risk for MHF outbreaks than previously realized and correspond well with a recently published report in which three species of fruit bats were demonstrated to be likely reservoirs for Ebola virus.

  2. Detection and diagnosis of rice-infecting viruses

    Directory of Open Access Journals (Sweden)

    Tamaki Uehara Ichiki

    2013-10-01

    Full Text Available Rice-infecting viruses have caused serious damage to rice production in Asian, American, and African countries, where about 30 rice viruses and diseases have been reported. To control these diseases, developing accurate, quick methods to detect and diagnose the viruses in the host plants and any insect vectors of the viruses is very important. Based on an antigen–antibody reaction, serological methods such as latex agglutination reaction (LAR and enzyme-linked immunosorbent assay (ELISA have advanced to detect viral particles or major proteins derived from viruses. They aid in forecasting disease and surveying disease spread and are widely used for virus detection at plant protection stations and research laboratories. From the early 2000s, based on sequence information for the target virus, several other methods such as reverse transcription-polymerase chain reaction (RT-PCR and reverse transcription- loop-mediated isothermal amplification (RT-LAMP have been developed that are sensitive, rapid, and able to differentiate closely related viruses. Recent techniques such as real-time RT-PCR can be used to quantify the pathogen in target samples and monitor population dynamics of a virus, and metagenomic analyses using next-generation sequencing and microarrays show potential for use in the diagnosis of rice diseases.

  3. 21 CFR 866.3360 - Lymphocytic choriomeningitis virus serological reagents.

    Science.gov (United States)

    2010-04-01

    ... cerebral meningitis (inflammation of membranes that envelop the brain) and occasionally a mild pneumonia... meningitis and pneumonia. (b) Classification. Class I (general controls). The device is exempt from...

  4. Possible Association Between Zika Virus Infection and Microcephaly - Brazil, 2015.

    Science.gov (United States)

    Schuler-Faccini, Lavinia; Ribeiro, Erlane M; Feitosa, Ian M L; Horovitz, Dafne D G; Cavalcanti, Denise P; Pessoa, André; Doriqui, Maria Juliana R; Neri, Joao Ivanildo; Neto, Joao Monteiro de Pina; Wanderley, Hector Y C; Cernach, Mirlene; El-Husny, Antonette S; Pone, Marcos V S; Serao, Cassio L C; Sanseverino, Maria Teresa V

    2016-01-29

    In early 2015, an outbreak of Zika virus, a flavivirus transmitted by Aedes mosquitoes, was identified in northeast Brazil, an area where dengue virus was also circulating. By September, reports of an increase in the number of infants born with microcephaly in Zika virus-affected areas began to emerge, and Zika virus RNA was identified in the amniotic fluid of two women whose fetuses had been found to have microcephaly by prenatal ultrasound. The Brazil Ministry of Health (MoH) established a task force to investigate the possible association of microcephaly with Zika virus infection during pregnancy and a registry for incident microcephaly cases (head circumference ≥2 standard deviations [SD] below the mean for sex and gestational age at birth) and pregnancy outcomes among women suspected to have had Zika virus infection during pregnancy. Among a cohort of 35 infants with microcephaly born during August-October 2015 in eight of Brazil's 26 states and reported to the registry, the mothers of all 35 had lived in or visited Zika virus-affected areas during pregnancy, 25 (71%) infants had severe microcephaly (head circumference >3 SD below the mean for sex and gestational age), 17 (49%) had at least one neurologic abnormality, and among 27 infants who had neuroimaging studies, all had abnormalities. Tests for other congenital infections were negative. All infants had a lumbar puncture as part of the evaluation and cerebrospinal fluid (CSF) samples were sent to a reference laboratory in Brazil for Zika virus testing; results are not yet available. Further studies are needed to confirm the association of microcephaly with Zika virus infection during pregnancy and to understand any other adverse pregnancy outcomes associated with Zika virus infection. Pregnant women in Zika virus-affected areas should protect themselves from mosquito bites by using air conditioning, screens, or nets when indoors, wearing long sleeves and pants, using permethrin-treated clothing and gear

  5. Early Events in Chikungunya Virus Infection-From Virus Cell Binding to Membrane Fusion

    NARCIS (Netherlands)

    van Duijl-Richter, Mareike K. S.; Hoornweg, Tabitha E.; Rodenhuis-Zybert, Izabela A.; Smit, Jolanda M.

    2015-01-01

    Chikungunya virus (CHIKV) is a rapidly emerging mosquito-borne alphavirus causing millions of infections in the tropical and subtropical regions of the world. CHIKV infection often leads to an acute self-limited febrile illness with debilitating myalgia and arthralgia. A potential long-term complica

  6. A fatal case of chikungunya virus infection with liver involvement.

    Science.gov (United States)

    Chua, H H; Abdul Rashid, K; Law, W C; Hamizah, A; Chem, Y K; Khairul, A H; Chua, K B

    2010-03-01

    Recovery from chikungunya is previously considered universal and mortality due to the virus is rare and unusual. Findings from recent chikungunya outbreaks occurred in Reunion Island and India have since challenged the conventional view on the benign nature of the illness. Malaysia has experienced at least of 4 outbreaks of chikungunya since 1998. In the present on-going large outbreak due to chikungunya virus of Central/East African genotype, a previous healthy sixty six years gentleman without co-morbidity was noted to have severe systemic infection by the virus and involvement of his liver. He subsequently passed away due to cardiovascular collapse after 5 days of illness.

  7. Hepatitis B and C virus co-infections in human immunodeficiency virus positive North Indian patients

    Institute of Scientific and Technical Information of China (English)

    Swati Gupta; Sarman Singh

    2006-01-01

    AIM:To determine the prevalence of hepatitis B and C virus infections in human immunodeficiency virus (HIV) -positive patients at a tertiary care hospital in New Delhi,India.METHODS:Serum samples from 451 HIV positive patients were analyzed for HBsAg and HCV antibodies during three years (Jan 2003-Dec 2005). The control group comprised of apparently healthy bone-marrow and renal donors.RESULTS:The study population comprised essentially of heterosexually transmitted HIV infection. The prevalence rate of HBsAg in this population was 5.3% as compared to 1.4% in apparently healthy donors (P < 0.001).Though prevalence of HCV co-infection (2.43%) was lower than HBV in this group of HIV positive patients,the prevalence was significantly higher (P < 0.05) than controls (0.7%). Triple infection of HIV, HBV and HCV was not detected in any patient.CONCLUSION:Our study shows a significantly high prevalence of hepatitis virus infections in HIV infected patients. Hepatitis viruses in HIV may lead to faster progression to liver cirrhosis and a higher risk of antiretroviral therapy induced hepatotoxicity. Therefore,it would be advisable to detect hepatitis virus coinfections in these patients at the earliest.

  8. Protective Effect of Dietary Xylitol on Influenza A Virus Infection

    OpenAIRE

    Sun Young Yin; Hyoung Jin Kim; Hong-Jin Kim

    2014-01-01

    Xylitol has been used as a substitute for sugar to prevent cavity-causing bacteria, and most studies have focused on its benefits in dental care. Meanwhile, the constituents of red ginseng (RG) are known to be effective in ameliorating the symptoms of influenza virus infection when they are administered orally for 14 days. In this study, we investigated the effect of dietary xylitol on influenza A virus infection (H1N1). We designed regimens containing various fractions of RG (RGs: whole extr...

  9. Beet western yellows virus infects the carnivorous plant Nepenthes mirabilis.

    Science.gov (United States)

    Miguel, Sissi; Biteau, Flore; Mignard, Benoit; Marais, Armelle; Candresse, Thierry; Theil, Sébastien; Bourgaud, Frédéric; Hehn, Alain

    2016-08-01

    Although poleroviruses are known to infect a broad range of higher plants, carnivorous plants have not yet been reported as hosts. Here, we describe the first polerovirus naturally infecting the pitcher plant Nepenthes mirabilis. The virus was identified through bioinformatic analysis of NGS transcriptome data. The complete viral genome sequence was assembled from overlapping PCR fragments and shown to share 91.1 % nucleotide sequence identity with the US isolate of beet western yellows virus (BWYV). Further analysis of other N. mirabilis plants revealed the presence of additional BWYV isolates differing by several insertion/deletion mutations in ORF5. PMID:27180098

  10. Tahyna virus genetics, infectivity, and immunogenicity in mice and monkeys

    Directory of Open Access Journals (Sweden)

    Whitehead Stephen S

    2011-03-01

    Full Text Available Abstract Background Tahyna virus (TAHV is a human pathogen of the California encephalitis virus (CEV serogroup (Bunyaviridae endemic to Europe, Asia, and Africa. TAHV maintains an enzootic life cycle with several species of mosquito vectors and hares, rabbits, hedgehogs, and rodents serving as small mammal amplifying hosts. Human TAHV infection occurs in summer and early fall with symptoms of fever, headache, malaise, conjunctivitis, pharyngitis, and nausea. TAHV disease can progress to CNS involvement, although unlike related La Crosse virus (LACV, fatalities have not been reported. Human infections are frequent with neutralizing antibodies present in 60-80% of the elderly population in endemic areas. Results In order to determine the genomic sequence of wild-type TAHV, we chose three TAHV isolates collected over a 26-year period from mosquitoes. Here we present the first complete sequence of the TAHV S, M, and L segments. The three TAHV isolates maintained a highly conserved genome with both nucleotide and amino acid sequence identity greater than 99%. In order to determine the extent of genetic relatedness to other members of the CEV serogroup, we compared protein sequences of TAHV with LACV, Snowshoe Hare virus (SSHV, Jamestown Canyon virus (JCV, and Inkoo virus (INKV. By amino acid comparison, TAHV was most similar to SSHV followed by LACV, JCV, and INKV. The sequence of the GN protein is most conserved followed by L, N, GC, NSS, and NSM. In a weanling Swiss Webster mouse model, all three TAHV isolates were uniformly neurovirulent, but only one virus was neuroinvasive. In rhesus monkeys, the virus was highly immunogenic even in the absence of viremia. Cross neutralization studies utilizing monkey immune serum demonstrated that TAHV is antigenically distinct from North American viruses LACV and JCV. Conclusions Here we report the first complete sequence of TAHV and present genetic analysis of new-world viruses, LACV, SSHV, and JCV with old

  11. Comparison of various ways of tick infection with the tick-borne encephalitis virus

    OpenAIRE

    VÝLETOVÁ, Eva

    2015-01-01

    The aim of the bachelor thesis was to compare various methods of Ixodes ricinus tick infection with the tick-borne encephalitis virus. For infection by immersion method, less virulent TBE virus strain Neudoerfl was used resulting in 5 % of infected ticks. Using more virulent strain Hypr provided 60 % of infected ticks. 75 % of ticks became infected with the Neudoerfl virus by capillary feeding. Infection of ticks by feeding on viraemic mice was unsuccessful. Applicability of tested methods fo...

  12. Transcriptome analysis of feline infectious peritonitis virus infection.

    Science.gov (United States)

    Mehrbod, Parvaneh; Harun, Mohammad Syamsul Reza; Shuid, Ahmad Naqib; Omar, Abdul Rahman

    2015-01-01

    Feline infectious peritonitis (FIP) is a lethal systemic disease caused by FIP virus (FIPV). There are no effective vaccines or treatment available, and the virus virulence determinants and pathogenesis are not fully understood. Here, we describe the sequencing of RNA extracted from Crandell Rees Feline Kidney (CRFK) cells infected with FIPV using the Illumina next-generation sequencing approach. Bioinformatics analysis, based on Felis catus 2X annotated shotgun reference genome, using CLC bio Genome Workbench is used to map both control and infected cells. Kal's Z test statistical analysis is used to analyze the differentially expressed genes from the infected CRFK cells. In addition, RT-qPCR analysis is used for further transcriptional profiling of selected genes in infected CRFK cells and Peripheral Blood Mononuclear Cells (PBMCs) from healthy and FIP-diagnosed cats.

  13. Aedes aegypti D7 Saliva Protein Inhibits Dengue Virus Infection

    Science.gov (United States)

    Conway, Michael J.; Londono-Renteria, Berlin; Troupin, Andrea; Watson, Alan M.; Klimstra, William B.; Fikrig, Erol; Colpitts, Tonya M.

    2016-01-01

    Aedes aegypti is the primary vector of several medically relevant arboviruses including dengue virus (DENV) types 1–4. Ae. aegypti transmits DENV by inoculating virus-infected saliva into host skin during probing and feeding. Ae. aegypti saliva contains over one hundred unique proteins and these proteins have diverse functions, including facilitating blood feeding. Previously, we showed that Ae. aegypti salivary gland extracts (SGEs) enhanced dissemination of DENV to draining lymph nodes. In contrast, HPLC-fractionation revealed that some SGE components inhibited infection. Here, we show that D7 proteins are enriched in HPLC fractions that are inhibitory to DENV infection, and that recombinant D7 protein can inhibit DENV infection in vitro and in vivo. Further, binding assays indicate that D7 protein can directly interact with DENV virions and recombinant DENV envelope protein. These data reveal a novel role for D7 proteins, which inhibits arbovirus transmission to vertebrates through a direct interaction with virions. PMID:27632170

  14. Oral conditions associated with Hepatitis C virus infection

    Directory of Open Access Journals (Sweden)

    Seyed-Moayed Alavian

    2013-01-01

    Full Text Available Hepatitis C virus (HCV infection in more than 170 million chronically infected patients with no developed preventive vaccine is a globally important issue. In addition to expected hepatic manifestations, a number of extrahepatic manifestations, such as mixed cryoglobulinemia, glomerulonephritis, polyarteritis nodosa, rashes, renal disease, neuropathy, and lymphoma, have been reported following HCV infection, which are believed to be influenced by the virus or the host immune response. HCV combination therapy with pegylated interferon and ribavirin might be associated with side effects as well. The association of HCV with special oral conditions has also been reported recurrently; the mechanism of most of which remains unclear. This article reviews the association of HCV infection with some of the oral conditions such as oral health, Sjogren′s syndrome, lichen planus and oral cancer.

  15. [HIV infection and parenteral virus hepatitis in the Krasnodar territory].

    Science.gov (United States)

    Larin, F I; Lebedev, V V; Red'ko, A N

    2005-01-01

    The analysis of the morbidity dynamics of HIV infection, hepatitis B and C in the Krasnodar territory for 1996-2003 is presented. The tendency of strengthening direct correlation between age-dependent rates in these groups of diseases has been established. The correlation coefficient (rxy) is at present +0.851 (HIV infection-virus hepatitis B) and +0.892 (HIV infection-virus hepatitis C). The highest levels of primary morbidity are registered in persons aged 20-39 years. The established epidemiological parallels between HIV infection and parenteral hepatitis require the development of the unified strategy of the prophylaxis of these diseases on the federal and regional levels. PMID:16028521

  16. Aedes aegypti D7 Saliva Protein Inhibits Dengue Virus Infection.

    Science.gov (United States)

    Conway, Michael J; Londono-Renteria, Berlin; Troupin, Andrea; Watson, Alan M; Klimstra, William B; Fikrig, Erol; Colpitts, Tonya M

    2016-09-01

    Aedes aegypti is the primary vector of several medically relevant arboviruses including dengue virus (DENV) types 1-4. Ae. aegypti transmits DENV by inoculating virus-infected saliva into host skin during probing and feeding. Ae. aegypti saliva contains over one hundred unique proteins and these proteins have diverse functions, including facilitating blood feeding. Previously, we showed that Ae. aegypti salivary gland extracts (SGEs) enhanced dissemination of DENV to draining lymph nodes. In contrast, HPLC-fractionation revealed that some SGE components inhibited infection. Here, we show that D7 proteins are enriched in HPLC fractions that are inhibitory to DENV infection, and that recombinant D7 protein can inhibit DENV infection in vitro and in vivo. Further, binding assays indicate that D7 protein can directly interact with DENV virions and recombinant DENV envelope protein. These data reveal a novel role for D7 proteins, which inhibits arbovirus transmission to vertebrates through a direct interaction with virions. PMID:27632170

  17. Characterization of Lethal Zika Virus Infection in AG129 Mice

    OpenAIRE

    Aliota, Matthew T; Elizabeth A Caine; Emma C Walker; Katrina E Larkin; Erwin Camacho; Jorge E Osorio

    2016-01-01

    Background Mosquito-borne Zika virus (ZIKV) typically causes a mild and self-limiting illness known as Zika fever, which often is accompanied by maculopapular rash, headache, and myalgia. During the current outbreak in South America, ZIKV infection during pregnancy has been hypothesized to cause microcephaly and other diseases. The detection of ZIKV in fetal brain tissue supports this hypothesis. Because human infections with ZIKV historically have remained sporadic and, until recently, have ...

  18. Experimental Everglades Virus Infection of Cotton Rats (Sigmodon hispidus)

    OpenAIRE

    Coffey, Lark L.; Carrara, Anne-Sophie; Paessler, Slobodan; Haynie, Michelle L.; BRADLEY, ROBERT D.; Tesh, Robert B.; Weaver, Scott C.

    2004-01-01

    Everglades virus (EVEV), an alphavirus in the Venezuelan equine encephalitis (VEE) serocomplex, circulates among rodents and vector mosquitoes and infects humans, causing a febrile disease sometimes accompanied by neurologic manifestations. EVEV circulates near metropolitan Miami, which indicates the potential for substantial human disease, should outbreaks arise. We characterized EVEV infection of cotton rats in South Florida, USA, to validate their role in enzootic transmission. To evaluate...

  19. Detection of Zika Virus Infection in Thailand, 2012–2014

    OpenAIRE

    Buathong, Rome; Hermann, Laura; Thaisomboonsuk, Butsaya; Rutvisuttinunt, Wiriya; Klungthong, Chonticha; Chinnawirotpisan, Piyawan; Manasatienkij, Wudtichai; Nisalak, Ananda; Fernandez, Stefan; Yoon, In-Kyu; Akrasewi, Passakorn; Plipat, Tanarak

    2015-01-01

    Zika virus (ZIKV) is an emerging mosquito-borne pathogen with reported cases in Africa, Asia, and large outbreaks in the Pacific. No autochthonous ZIKV infections have been confirmed in Thailand. However, there have been several cases reported in travelers returning from Thailand. Here we report seven cases of acute ZIKV infection in Thai residents across the country confirmed by molecular or serological testing including sequence data. These endemic cases, combined with previous reports in t...

  20. Noninfectious Pulmonary Complications of Human Immunodeficiency Virus Infection

    OpenAIRE

    Staitieh, Bashar; Guidot, David M.

    2014-01-01

    Abstract: Human immunodeficiency virus type 1 (HIV-1) is the retrovirus responsible for the development of AIDS. Its profound impact on the immune system leaves the host vulnerable to a wide range of opportunistic infections not seen in individuals with a competent immune system. Pulmonary infections dominated the presentations in the early years of the epidemic, and infectious and noninfectious lung diseases remain the leading causes of morbidity and mortality in persons living with HIV desp...

  1. Simian varicella virus infection of Chinese rhesus macaques produces ganglionic infection in the absence of rash

    NARCIS (Netherlands)

    W.J.D. Ouwendijk (Werner ); R. Mahalingam (Ravi); V. Traina-Dorge (Vicki); G. van Amerongen (Geert); M. Wellish (Mary); A.D.M.E. Osterhaus (Albert); D. Gilden (Don); G.M.G.M. Verjans (George)

    2012-01-01

    textabstractVaricella-zoster virus (VZV) causes varicella (chickenpox), becomes latent in ganglia along the entire neuraxis, and may reactivate to cause herpes zoster (shingles). VZV may infect ganglia via retrograde axonal transport from infected skin or through hematogenous spread. Simian varicell

  2. Experimental infection of vertebrates of the Pocomoke Cypress Swamp, Maryland with Keystone and Jamestown Canyon viruses.

    Science.gov (United States)

    Watts, D M; Tammariello, R F; Dalrymple, J M; Eldridge, B F; Russell, P K; Top, F H

    1979-03-01

    Experimental studies were conducted to assess the susceptibility of white-tailed deer (Odocoileus virginianus), gray squirrels (Sciurus carolinensis), and cottontail rabbits (Sylvilagus floridanus) to Jamestown Canyon (JC) and/or Keystone (KEY) virus infection. Viremia occurred in 5 of 6 deer inoculated with JC virus; however, all deer developed KEY virus neutralizing antibody. Based on the observation that antibody elicited by primary infection of deer with either KEY or JC virus exhibited partial heterologous neutralization in vitro, cross-challenge experiments were performed in these animals. Keystone virus failed to infect deer 30 days post primary JC virus infection; however, deer became infected when challenged with KEY virus 80 days after the initial JC virus infection as indicated by a substantial increase in antibody titer. Similarly, JC virus failed to produce viremia in immune animals infected with KEY virus 80 days previously, although 2 of the 3 animals challenged had serological evidence of infection. Three field-collected cottontail rabbits with no evidence of KEY antibody were readily susceptible to KEY virus infection and developed viremias of 1-4 days' duration; rabbits with KEY virus antibody did not develop viremia upon KEY virus challenge. Eight antibody-negative field-collected gray squirrels became viremic following injection with KEY virus; however, a comparable group of squirrels did not become viremic when injected with JC virus. PMID:453437

  3. Alteration of cell cycle progression by Sindbis virus infection

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Ruirong; Saito, Kengo [Department of Molecular Virology, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan); Isegawa, Naohisa [Laboratory Animal Center, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan); Shirasawa, Hiroshi, E-mail: sirasawa@faculty.chiba-u.jp [Department of Molecular Virology, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan)

    2015-07-10

    We examined the impact of Sindbis virus (SINV) infection on cell cycle progression in a cancer cell line, HeLa, and a non-cancerous cell line, Vero. Cell cycle analyses showed that SINV infection is able to alter the cell cycle progression in both HeLa and Vero cells, but differently, especially during the early stage of infection. SINV infection affected the expression of several cell cycle regulators (CDK4, CDK6, cyclin E, p21, cyclin A and cyclin B) in HeLa cells and caused HeLa cells to accumulate in S phase during the early stage of infection. Monitoring SINV replication in HeLa and Vero cells expressing cell cycle indicators revealed that SINV which infected HeLa cells during G{sub 1} phase preferred to proliferate during S/G{sub 2} phase, and the average time interval for viral replication was significantly shorter in both HeLa and Vero cells infected during G{sub 1} phase than in cells infected during S/G{sub 2} phase. - Highlights: • SINV infection was able to alter the cell cycle progression of infected cancer cells. • SINV infection can affect the expression of cell cycle regulators. • SINV infection exhibited a preference for the timing of viral replication among the cell cycle phases.

  4. The Effects of High Temperature on Infection by Potato virus Y, Potato virus A, and Potato leafroll virus.

    Science.gov (United States)

    Chung, Bong Nam; Canto, Tomas; Tenllado, Francisco; Choi, Kyung San; Joa, Jae Ho; Ahn, Jeong Joon; Kim, Chun Hwan; Do, Ki Seck

    2016-08-01

    We examined the effects of temperature on acquisition of Potato virus Y-O (PVY-O), Potato virus A (PVA), and Potato leafroll virus (PLRV) by Myzus persicae by performing transmission tests with aphids that acquired each virus at different temperatures. Infection by PVY-O/PVA and PLRV increased with increasing plant temperature in Nicotiana benthamiana and Physalis floridana, respectively, after being transmitted by aphids that acquired them within a temperature range of 10-20°C. However, infection rates subsequently decreased. Direct qRT-PCR of RNA extracted from a single aphid showed that PLRV infection increased in the 10-20°C range, but this trend also declined shortly thereafter. We examined the effect of temperature on establishment of virus infection. The greatest number of plants became infected when N. benthamiana was held at 20°C after inoculation with PVY-O or PVA. The largest number of P. floridana plants became infected with PLRV when the plants were maintained at 25°C. PLRV levels were highest in P. floridana kept at 20-25°C. These results indicate that the optimum temperatures for proliferation of PVY-O/PVA and PLRV differed. Western blot analysis showed that accumulations of PVY-O and PVA coat proteins (CPs) were lower at 10°C or 15°C than at 20°C during early infection. However, accumulation increased over time. At 25°C or 30°C, the CPs of both viruses accumulated during early infection but disappeared as time passed. Our results suggest that symptom attenuation and reduction of PVY-O and PVA CP accumulation at higher temperatures appear to be attributable to increased RNA silencing. PMID:27493607

  5. ROLE OF THE SEROLOGIC TEST FOR DENGUE VIRUS INFECTION

    Directory of Open Access Journals (Sweden)

    Ni Luh Sinta Purnama Dewi

    2013-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Dengue virus infection is infection disease cause by dengue virus. Dengue virus infection can cause a broad spectrum disease such as : dengue fever (DF, dengue hemorrhagic fever (DHF, and dengue shock syndrome (DSS. Currently dengue virus ranks eighth as a cause of illness in the State of South-East Asia and Western Pacific. Epidemic dengue hemorrhagic fever (DHF occur each year in Indonesia with a tendency incident and the affected area is increasing. Laboratory tests can be done to detect the dengue virus infection: a complete blood count and serology. Of serology test, positive IgM antibody showed that patients had a primary infection, whereas patients with secondary infections showed positive IgG antibodies, usually accompanied by antibody IgM positive. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  6. Induction of apoptosis in frog virus 3-infected cells.

    Science.gov (United States)

    Chinchar, V G; Bryan, Locke; Wang, J; Long, Scott; Chinchar, G D

    2003-02-15

    The ability of frog virus 3 (FV3), the type species of the family Iridoviridae, to induce apoptosis was examined by monitoring DNA cleavage, chromatin condensation, and cell-surface expression of phosphotidylserine (PS) in fathead minnow (FHM) and baby hamster kidney (BHK) cells. In productively infected FHM cells, DNA fragmentation was first noted at 6-7 h postinfection and was clearly seen by 17 h postinfection, while chromatin condensation was detected at 8.5 h postinfection. As with some other viruses, FV3-induced apoptosis did not require de novo viral gene expression as both heat-inactivated and UV-inactivated virus readily triggered DNA fragmentation in FHM cells. Moreover, FV3-induced apoptosis was blocked in FHM cells by the pan-caspase inhibitor Z-VAD-FMK, suggesting that virus infection triggers programmed cell death through activation of the caspase cascade. FV3 infection also triggered apoptosis in BHK cells as monitored by TUNEL and annexin V binding assays. To determine whether FV3, similar to other large DNA viruses, encoded proteins that block or delay apoptosis, mock- and FV3-infected FHM cells were osmotically shocked and assayed for DNA fragmentation 3 hours later. DNA fragmentation was clearly seen whether or not shocked cells were previously infected with FV3, indicating that infection with FV3 did not block apoptosis induced by osmotic shock in FHM cells. The above results demonstrate that iridoviruses triggered apoptosis and that the induction of programmed cell death did not require viral gene expression. However, it remains to be determined if virion attachment to target cells is sufficient to induce cell death, or if apoptosis is triggered directly or indirectly by one or more virion-associated proteins. PMID:12642103

  7. Host sphingomyelin increases West Nile virus infection in vivo.

    Science.gov (United States)

    Martín-Acebes, Miguel A; Gabandé-Rodríguez, Enrique; García-Cabrero, Ana M; Sánchez, Marina P; Ledesma, María Dolores; Sobrino, Francisco; Saiz, Juan-Carlos

    2016-03-01

    Flaviviruses, such as the dengue virus and the West Nile virus (WNV), are arthropod-borne viruses that represent a global health problem. The flavivirus lifecycle is intimately connected to cellular lipids. Among the lipids co-opted by flaviviruses, we have focused on SM, an important component of cellular membranes particularly enriched in the nervous system. After infection with the neurotropic WNV, mice deficient in acid sphingomyelinase (ASM), which accumulate high levels of SM in their tissues, displayed exacerbated infection. In addition, WNV multiplication was enhanced in cells from human patients with Niemann-Pick type A, a disease caused by a deficiency of ASM activity resulting in SM accumulation. Furthermore, the addition of SM to cultured cells also increased WNV infection, whereas treatment with pharmacological inhibitors of SM synthesis reduced WNV infection. Confocal microscopy analyses confirmed the association of SM with viral replication sites within infected cells. Our results unveil that SM metabolism regulates flavivirus infection in vivo and propose SM as a suitable target for antiviral design against WNV. PMID:26764042

  8. Neutralizing Antibodies and Pathogenesis of Hepatitis C Virus Infection

    Directory of Open Access Journals (Sweden)

    Françoise Stoll-Keller

    2012-10-01

    Full Text Available Hepatitis C virus (HCV infection is a major cause of chronic liver disease worldwide. The interplay between the virus and host innate and adaptive immune responses determines the outcome of infection. There is increasing evidence that host neutralizing responses play a relevant role in the resulting pathogenesis. Furthermore, viral evasion from host neutralizing antibodies has been revealed to be an important contributor in leading both to viral persistence in acute liver graft infection following liver transplantation, and to chronic viral infection. The development of novel model systems to study HCV entry and neutralization has allowed a detailed understanding of the molecular mechanisms of virus-host interactions during antibody-mediated neutralization. The understanding of these mechanisms will ultimately contribute to the development of novel antiviral preventive strategies for liver graft infection and an urgently needed vaccine. This review summarizes recent concepts of the role of neutralizing antibodies in viral clearance and protection, and highlights consequences of viral escape from neutralizing antibodies in the pathogenesis of HCV infection.

  9. Host sphingomyelin increases West Nile virus infection in vivo.

    Science.gov (United States)

    Martín-Acebes, Miguel A; Gabandé-Rodríguez, Enrique; García-Cabrero, Ana M; Sánchez, Marina P; Ledesma, María Dolores; Sobrino, Francisco; Saiz, Juan-Carlos

    2016-03-01

    Flaviviruses, such as the dengue virus and the West Nile virus (WNV), are arthropod-borne viruses that represent a global health problem. The flavivirus lifecycle is intimately connected to cellular lipids. Among the lipids co-opted by flaviviruses, we have focused on SM, an important component of cellular membranes particularly enriched in the nervous system. After infection with the neurotropic WNV, mice deficient in acid sphingomyelinase (ASM), which accumulate high levels of SM in their tissues, displayed exacerbated infection. In addition, WNV multiplication was enhanced in cells from human patients with Niemann-Pick type A, a disease caused by a deficiency of ASM activity resulting in SM accumulation. Furthermore, the addition of SM to cultured cells also increased WNV infection, whereas treatment with pharmacological inhibitors of SM synthesis reduced WNV infection. Confocal microscopy analyses confirmed the association of SM with viral replication sites within infected cells. Our results unveil that SM metabolism regulates flavivirus infection in vivo and propose SM as a suitable target for antiviral design against WNV.

  10. Potent neutralizing monoclonal antibodies against Ebola virus infection

    Science.gov (United States)

    Zhang, Qi; Gui, Miao; Niu, Xuefeng; He, Shihua; Wang, Ruoke; Feng, Yupeng; Kroeker, Andrea; Zuo, Yanan; Wang, Hua; Wang, Ying; Li, Jiade; Li, Chufang; Shi, Yi; Shi, Xuanling; Gao, George F.; Xiang, Ye; Qiu, Xiangguo; Chen, Ling; Zhang, Linqi

    2016-01-01

    Ebola virus infections cause a deadly hemorrhagic disease for which no vaccines or therapeutics has received regulatory approval. Here we show isolation of three (Q206, Q314 and Q411) neutralizing monoclonal antibodies (mAbs) against the surface glycoprotein (GP) of Ebola virus identified in West Africa in 2014 through sequential immunization of Chinese rhesus macaques and antigen-specific single B cell sorting. These mAbs demonstrated potent neutralizing activities against both pseudo and live Ebola virus independent of complement. Biochemical, single particle EM, and mutagenesis analysis suggested Q206 and Q411 recognized novel epitopes in the head while Q314 targeted the glycan cap in the GP1 subunit. Q206 and Q411 appeared to influence GP binding to its receptor NPC1. Treatment with these mAbs provided partial but significant protection against disease in a mouse model of Ebola virus infection. These novel mAbs could serve as promising candidates for prophylactic and therapeutic interventions against Ebola virus infection. PMID:27181584

  11. Discovery of mammalian genes that participate in virus infection

    Directory of Open Access Journals (Sweden)

    Sheng Jinsong

    2004-11-01

    Full Text Available Abstract Background Viruses are obligate intracellular parasites that rely upon the host cell for different steps in their life cycles. The characterization of cellular genes required for virus infection and/or cell killing will be essential for understanding viral life cycles, and may provide cellular targets for new antiviral therapies. Results Candidate genes required for lytic reovirus infection were identified by tagged sequence mutagenesis, a process that permits rapid identification of genes disrupted by gene entrapment. One hundred fifty-one reovirus resistant clones were selected from cell libraries containing 2 × 105 independently disrupted genes, of which 111 contained mutations in previously characterized genes and functionally anonymous transcription units. Collectively, the genes associated with reovirus resistance differed from genes targeted by random gene entrapment in that known mutational hot spots were under represented, and a number of mutations appeared to cluster around specific cellular processes, including: IGF-II expression/signalling, vesicular transport/cytoskeletal trafficking and apoptosis. Notably, several of the genes have been directly implicated in the replication of reovirus and other viruses at different steps in the viral lifecycle. Conclusions Tagged sequence mutagenesis provides a rapid, genome-wide strategy to identify candidate cellular genes required for virus infection. The candidate genes provide a starting point for mechanistic studies of cellular processes that participate in the virus lifecycle and may provide targets for novel anti-viral therapies.

  12. Cyclophilin A protects mice against infection by influenza A virus

    Science.gov (United States)

    Li, Jing; Chen, Can; Wong, Gary; Dong, Wei; Zheng, Weinan; Li, Yun; Sun, Lei; Zhang, Lianfeng; Gao, George F.; Bi, Yuhai; Liu, Wenjun

    2016-01-01

    Our previous studies indicate that Cyclophilin A (CypA) impairs the replication of influenza A virus in vitro. To further evaluate the antiviral functions of CypA and explore its mechanism, transgenic mice with overexpression of CypA by two specific promoters with SPC (CypA-SPC) or CMV (CypA-CMV) were developed. After challenge with the A/WSN/33(H1N1) influenza virus, CypA-SPC and CypA-CMV transgenic mice displayed nearly 2.5- and 3.8-fold stronger disease resistance to virus infection, respectively, compared to wild-type animals. Virus replication, pathological lesions and inflammatory cytokines were substantially reduced in both lines of transgenic mice. In addition, after infection there was an upregulation of genes associated with cell migration, immune function, and organ development; and a downregulation of genes associated with the positive regulation of immune cells and apoptosis in the peritoneal macrophages of CypA-overexpressing transgenic mice (CypA+). These results indicate that CypA is a key modulator of influenza virus resistance in mice, and that CypA+ mice constitutes an important model to study the roles of CypA in the regulation of immune responses and infections. PMID:27354005

  13. Cyclophilin A protects mice against infection by influenza A virus.

    Science.gov (United States)

    Li, Jing; Chen, Can; Wong, Gary; Dong, Wei; Zheng, Weinan; Li, Yun; Sun, Lei; Zhang, Lianfeng; Gao, George F; Bi, Yuhai; Liu, Wenjun

    2016-01-01

    Our previous studies indicate that Cyclophilin A (CypA) impairs the replication of influenza A virus in vitro. To further evaluate the antiviral functions of CypA and explore its mechanism, transgenic mice with overexpression of CypA by two specific promoters with SPC (CypA-SPC) or CMV (CypA-CMV) were developed. After challenge with the A/WSN/33(H1N1) influenza virus, CypA-SPC and CypA-CMV transgenic mice displayed nearly 2.5- and 3.8-fold stronger disease resistance to virus infection, respectively, compared to wild-type animals. Virus replication, pathological lesions and inflammatory cytokines were substantially reduced in both lines of transgenic mice. In addition, after infection there was an upregulation of genes associated with cell migration, immune function, and organ development; and a downregulation of genes associated with the positive regulation of immune cells and apoptosis in the peritoneal macrophages of CypA-overexpressing transgenic mice (CypA+). These results indicate that CypA is a key modulator of influenza virus resistance in mice, and that CypA+ mice constitutes an important model to study the roles of CypA in the regulation of immune responses and infections. PMID:27354005

  14. Shedding of Hepatitis C Virus in Semen of Human Immunodeficiency Virus-Infected Men.

    Science.gov (United States)

    Turner, Samuel S; Gianella, Sara; Yip, Marcus J-S; van Seggelen, Wouter O; Gillies, Robert D; Foster, Andrew L; Barbati, Zachary R; Smith, Davey M; Fierer, Daniel S

    2016-03-01

    Background.  The epidemic of sexually transmitted hepatitis C virus (HCV) infection among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) has been documented for over a decade. Despite this, there is no consensus as to the risk factors for sexual acquisition of HCV in these men. Methods.  We obtained paired semen and blood samples at 2-week intervals from HIV-infected MSM with recent and chronic HCV infection and quantified HCV in semen. Results.  Hepatitis C virus was quantified in 59 semen specimens from 33 men. Hepatitis C virus was shed in 16 (27%) of semen specimens from 11 (33%) of the men. Median HCV viral load (VL) in semen was 1.49 log10 IU/mL. Hepatitis C virus VL in blood was significantly higher at the time of HCV shedding in semen than when HCV shedding in semen was not detected (P = .002). Furthermore, there was a significant correlation between the HCV VL in blood and semen overall (rs = 0.41; P = .001), and in the subgroup with recent HCV infection (rs = 0.37; P = .02), but not in the subgroup with chronic HCV infection (rs = 0.34; P = .1). Conclusions.  One third of HIV-infected MSM coinfected with HCV shed HCV into their semen. Based on the HCV VL in semen in this study, an average ejaculate would deliver up to 6630 IU of virus into the rectum of the receptive partner. Therefore, our data strongly support that condoms should be used during anal intercourse among MSM to prevent transmission of HCV. PMID:27186582

  15. Prevalence of Hepatitis B Virus Infection in Kenya, 2007.

    Science.gov (United States)

    Ly, Kathleen N; Kim, Andrea A; Umuro, Mamo; Drobenuic, Jan; Williamson, John M; Montgomery, Joel M; Fields, Barry S; Teshale, Eyasu H

    2016-08-01

    Current estimates put the prevalence of hepatitis B virus (HBV) infection in Kenya at 5-8%. We determined the HBV infection prevalence in the human immunodeficiency virus (HIV)-negative Kenyan adult and adolescent population based on samples collected from a national survey. We analyzed data from HIV-negative participants in the 2007 Kenya AIDS Indicator Survey to estimate the HBV infection prevalence. We defined past or present HBV infection as presence of total hepatitis B core antibody (HBcAb), and chronic HBV infection (CHBI) as presence of both total HBcAb and hepatitis B surface antigen (HBsAg). We calculated crude and adjusted odds of HBV infection by demographic characteristics and risk factors using logistic regression analyses. Of 1,091 participants aged 15-64 years, approximately 31.5% (95% confidence interval [CI] = 28.0-35.3%) had exposure to HBV, corresponding to approximately 6.1 million (CI = 5.4-6.8 million) with past or present HBV infection. The estimated prevalence of CHBI was 2.1% (95% CI = 1.4-3.1%), corresponding to approximately 398,000 (CI = 261,000-602,000) with CHBI. CHBI is a major public health problem in Kenya, affecting approximately 400,000 persons. Knowing the HBV infection prevalence at baseline is important for planning and public health policy decision making and for monitoring the impact of viral hepatitis prevention programs. PMID:27273644

  16. Transgenic tomato hybrids resistant to tomato spotted wilt virus infection.

    NARCIS (Netherlands)

    Haan, de P.; Ultzen, T.; Prins, M.; Gielen, J.; Goldbach, R.; Grinsven, van M.

    1996-01-01

    Tomato spotted wilt virus (TSWV) infections cause significant economic losses in the commercial culture of tomato (Lycopersicon esculentum). Culture practices have only been marginally effective in controlling TSWV. The ultimate way to minimize losses caused by TSWV is resistant varieties. These can

  17. Vaccination against feline immunodeficiency virus using fixed infected cells

    NARCIS (Netherlands)

    Horzinek, M.C.; Verschoor, E.J.; Vliet, A.L.W. van; Egberink, H.F.; Hesselink, W.; Alphen, W.E. van; Joosten, I.; Boog, C.J.P.; Ronde, A. de

    1995-01-01

    Crandell feline kidney cells and feline thymocytes, either feline immunodeficiency virus (FIV) infected or uninfected, were fixed with paraformaldehyde and used to vaccinate cats. The cells were mixed with a 30:70 water/mineral oil emulsion containing 250 mu g ml−1 N-acetyl-d-glucosaminyl-beta-(1 4)

  18. Pneumocystosis associated with canine distemper virus infection in a mink.

    OpenAIRE

    Dyer, N W; Schamber, G J

    1999-01-01

    An adult mink from a farm experiencing 100% mortality in affected animals was submitted for diagnostic examination. Clinical history included signs of respiratory disease, oculonasal discharge, and thickening of footpads. Canine distemper virus and Pneumocystis carinii were identified in lung tissue, suggesting immunosuppresion and secondary infection due to morbillivirus disease.

  19. Influenza A virus and secondary bacterial infection in swine

    Science.gov (United States)

    Influenza A virus (IAV) infection alone causes significant disease characterized by respiratory distress and poor growth in pigs. Endemic strains of IAV in North America pigs consist of the subtypes H1N1, H1N2, and H3N2. These circulating strains contain the triple reassortant internal gene (TRIG) c...

  20. Regulatory T Cells in Chronic Hepatitis B Virus Infection

    NARCIS (Netherlands)

    J.N. Stoop (Jeroen Nicolaas)

    2007-01-01

    textabstractWorldwide 400 million people suffer from chronic hepatitis B virus (HBV) infection and approximately 1 million people die annually from HBV-related disease. To clear HBV, an effective immune response, in which several cell types and cytokines play a role, is important. It is known that p

  1. Therapeutic vaccination against chronic hepatitis C virus infection

    NARCIS (Netherlands)

    Ip, Peng Peng; Nijman, Hans W.; Wilschut, Jan; Daemen, Toos

    2012-01-01

    Approximately 170 million people worldwide are chronic carriers of Hepatitis C virus (HCV). To date, there is no prophylactic vaccine available against HCV. The standard-of-care therapy for HCV infection involves a combination of pegylated interferon-α and ribavirin. This therapy, which is commonly

  2. Neutralizing antibodies in cats infected with feline immunodeficiency virus.

    NARCIS (Netherlands)

    F. Tozzini; D. Matteucci; P. Bandecchi; F. Baldinotti; C.H.J. Siebelink (Kees); A.D.M.E. Osterhaus (Albert); M. Bendinelli

    1993-01-01

    textabstractSera from cats experimentally infected with five isolates of feline immunodeficiency virus (FIV) from various geographical regions and from FIV enzyme-linked immunosorbent assay-seropositive field cats from four European countries neutralized the Petaluma strain of FIV (FIV-P), originall

  3. Protective effect of dietary xylitol on influenza A virus infection.

    Science.gov (United States)

    Yin, Sun Young; Kim, Hyoung Jin; Kim, Hong-Jin

    2014-01-01

    Xylitol has been used as a substitute for sugar to prevent cavity-causing bacteria, and most studies have focused on its benefits in dental care. Meanwhile, the constituents of red ginseng (RG) are known to be effective in ameliorating the symptoms of influenza virus infection when they are administered orally for 14 days. In this study, we investigated the effect of dietary xylitol on influenza A virus infection (H1N1). We designed regimens containing various fractions of RG (RGs: whole extract, water soluble fraction, saponin and polysaccharide) and xylitol, and combination of xylitol with the RG fractions. Mice received the various combinations orally for 5 days prior to lethal influenza A virus infection. Almost all the mice died post challenge when xylitol or RGs were administered separately. Survival was markedly enhanced when xylitol was administered along with RGs, pointing to a synergistic effect. The effect of xylitol plus RG fractions increased with increasing dose of xylitol. Moreover, dietary xylitol along with the RG water soluble fraction significantly reduced lung virus titers after infection. Therefore, we suggest that dietary xylitol is effective in ameliorating influenza-induced symptoms when it is administered with RG fractions, and this protective effect of xylitol should be considered in relation to other diseases. PMID:24392148

  4. Protective Effect of Dietary Xylitol on Influenza A Virus Infection

    Science.gov (United States)

    Yin, Sun Young; Kim, Hyoung Jin; Kim, Hong-Jin

    2014-01-01

    Xylitol has been used as a substitute for sugar to prevent cavity-causing bacteria, and most studies have focused on its benefits in dental care. Meanwhile, the constituents of red ginseng (RG) are known to be effective in ameliorating the symptoms of influenza virus infection when they are administered orally for 14 days. In this study, we investigated the effect of dietary xylitol on influenza A virus infection (H1N1). We designed regimens containing various fractions of RG (RGs: whole extract, water soluble fraction, saponin and polysaccharide) and xylitol, and combination of xylitol with the RG fractions. Mice received the various combinations orally for 5 days prior to lethal influenza A virus infection. Almost all the mice died post challenge when xylitol or RGs were administered separately. Survival was markedly enhanced when xylitol was administered along with RGs, pointing to a synergistic effect. The effect of xylitol plus RG fractions increased with increasing dose of xylitol. Moreover, dietary xylitol along with the RG water soluble fraction significantly reduced lung virus titers after infection. Therefore, we suggest that dietary xylitol is effective in ameliorating influenza-induced symptoms when it is administered with RG fractions, and this protective effect of xylitol should be considered in relation to other diseases. PMID:24392148

  5. Hepatitis C virus infection of cholangiocarcinoma cell lines

    NARCIS (Netherlands)

    Fletcher, Nicola F.; Humphreys, Elizabeth; Jennings, Elliott; Osburn, William; Lissauer, Samantha; Wilson, Garrick K.; van Ijzendoorn, Sven C. D.; Baumert, Thomas F.; Balfe, Peter; Afford, Simon; McKeating, Jane A.

    2015-01-01

    Hepatitis C virus (HCV) infects the liver and hepatocytes are the major cell type supporting viral replication. Hepatocytes and cholangiocytes derive from a common hepatic progenitor cell that proliferates during inflammatory conditions, raising the possibility that cholangiocytes may support HCV re

  6. Protective effect of dietary xylitol on influenza A virus infection.

    Directory of Open Access Journals (Sweden)

    Sun Young Yin

    Full Text Available Xylitol has been used as a substitute for sugar to prevent cavity-causing bacteria, and most studies have focused on its benefits in dental care. Meanwhile, the constituents of red ginseng (RG are known to be effective in ameliorating the symptoms of influenza virus infection when they are administered orally for 14 days. In this study, we investigated the effect of dietary xylitol on influenza A virus infection (H1N1. We designed regimens containing various fractions of RG (RGs: whole extract, water soluble fraction, saponin and polysaccharide and xylitol, and combination of xylitol with the RG fractions. Mice received the various combinations orally for 5 days prior to lethal influenza A virus infection. Almost all the mice died post challenge when xylitol or RGs were administered separately. Survival was markedly enhanced when xylitol was administered along with RGs, pointing to a synergistic effect. The effect of xylitol plus RG fractions increased with increasing dose of xylitol. Moreover, dietary xylitol along with the RG water soluble fraction significantly reduced lung virus titers after infection. Therefore, we suggest that dietary xylitol is effective in ameliorating influenza-induced symptoms when it is administered with RG fractions, and this protective effect of xylitol should be considered in relation to other diseases.

  7. Special Issue: Viruses Infecting Fish, Amphibians, and Reptiles

    Directory of Open Access Journals (Sweden)

    V. Gregory Chinchar

    2011-09-01

    Full Text Available Although viruses infecting and affecting humans are the focus of considerable research effort, viruses that target other animal species, including cold-blooded vertebrates, are receiving increased attention. In part this reflects the interests of comparative virologists, but increasingly it is based on the impact that many viruses have on ecologically and commercially important animals. Frogs and other amphibians are sentinels of environmental health and their disappearance following viral or fungal (chytrid infection is a cause for alarm. Likewise, because aquaculture and mariculture are providing an increasingly large percentage of the “seafood” consumed by humans, viral agents that adversely impact the harvest of cultured fish and amphibians are of equal concern. [...

  8. Zika Virus Infection and Microcephaly: Evidence for a Causal Link

    Directory of Open Access Journals (Sweden)

    Jin-Na Wang

    2016-10-01

    Full Text Available Zika virus (ZIKV is a flavivirus related to the Dengue, yellow fever and West Nile viruses. Since the explosive outbreaks of ZIKV in Latin America in 2015, a sudden increase in the number of microcephaly cases has been observed in infants of women who were pregnant when they contracted the virus. The severity of this condition raises grave concerns, and extensive studies on the possible link between ZIKV infection and microcephaly have been conducted. There is substantial evidence suggesting that there is a causal link between ZIKV and microcephaly, however, future studies are warranted to solidify this association. To summarize the most recent evidence on this issue and provide perspectives for future studies, we reviewed the literature to identify existing evidence of the causal link between ZIKV infection and microcephaly within research related to the epidemics, laboratory diagnosis, and possible mechanisms.

  9. Evidence of Apeu Virus Infection in Wild Monkeys, Brazilian Amazon.

    Science.gov (United States)

    Oliveira, Danilo B; Luiz, Ana Paula Moreira Franco; Fagundes, Alexandre; Pinto, Carla Amaral; Bonjardim, Cláudio A; Trindade, Giliane S; Kroon, Erna G; Abrahão, Jônatas S; Ferreira, Paulo C P

    2016-03-01

    Orthobunyaviruses are arboviruses in which at least 30 members are human pathogens. The members of group C orthobunyaviruses were first isolated in the Brazilian Amazon in 1950, since that time little information is accumulated about ecology and the medical impact of these virus groups in Brazil. Herein, we describe the evidence of Apeu virus (APEUV; an Orthobunyavirus member) infection in wild monkeys from the Brazilian Amazon forest. APEUV was detected by using a neutralizing antibody in serum and its RNA, suggesting past and acute infection of Amazonian monkeys by this virus. These results altogether represent an important contribution of orthobunyavirus ecology in the Amazon and an update about recent circulation and risk for humans with expansion of the cities to Amazon forest.

  10. Clinical significance of occult hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    Miriam Romero; Antonio Madejón; Conrado Fernández-Rodríguez; Javier García-Samaniego

    2011-01-01

    Occult hepatitis B virus (HBV) infection (OBI) is defined as the presence of HBV DNA in the liver (with or without detectable HBV DNA in serum) for individuals testing HBV surface antigen negative. Until recently, the clinical effect of OBI was unclear on the progression of liver disease; on the development of hepatocellular carcinoma; and on the risk for reactivation or transmission of HBV infection. Several studies suggest a high prevalence of OBI among patients with cryptogenic chronic liver disease, but its role in the progression to cirrhosis remains unclear. Although OBI has been well documented in human immunodeficiency virus (HIV)-positive patients, especially among those coinfected with hepatitis C virus, further studies are needed to determine its current clinical impact in HIV setting.

  11. Zika Virus Infection in Mice Causes Panuveitis with Shedding of Virus in Tears.

    Science.gov (United States)

    Miner, Jonathan J; Sene, Abdoulaye; Richner, Justin M; Smith, Amber M; Santeford, Andrea; Ban, Norimitsu; Weger-Lucarelli, James; Manzella, Francesca; Rückert, Claudia; Govero, Jennifer; Noguchi, Kevin K; Ebel, Gregory D; Diamond, Michael S; Apte, Rajendra S

    2016-09-20

    Zika virus (ZIKV) is an emerging flavivirus that causes congenital abnormalities and Guillain-Barré syndrome. ZIKV infection also results in severe eye disease characterized by optic neuritis, chorioretinal atrophy, and blindness in newborns and conjunctivitis and uveitis in adults. We evaluated ZIKV infection of the eye by using recently developed mouse models of pathogenesis. ZIKV-inoculated mice developed conjunctivitis, panuveitis, and infection of the cornea, iris, optic nerve, and ganglion and bipolar cells in the retina. This phenotype was independent of the entry receptors Axl or Mertk, given that Axl(-/-), Mertk(-/-), and Axl(-/-)Mertk(-/-) double knockout mice sustained levels of infection similar to those of control animals. We also detected abundant viral RNA in tears, suggesting that virus might be secreted from lacrimal glands or shed from the cornea. This model provides a foundation for studying ZIKV-induced ocular disease, defining mechanisms of viral persistence, and developing therapeutic approaches for viral infections of the eye. PMID:27612415

  12. Human Ebola virus infection results in substantial immune activation.

    Science.gov (United States)

    McElroy, Anita K; Akondy, Rama S; Davis, Carl W; Ellebedy, Ali H; Mehta, Aneesh K; Kraft, Colleen S; Lyon, G Marshall; Ribner, Bruce S; Varkey, Jay; Sidney, John; Sette, Alessandro; Campbell, Shelley; Ströher, Ute; Damon, Inger; Nichol, Stuart T; Spiropoulou, Christina F; Ahmed, Rafi

    2015-04-14

    Four Ebola patients received care at Emory University Hospital, presenting a unique opportunity to examine the cellular immune responses during acute Ebola virus infection. We found striking activation of both B and T cells in all four patients. Plasmablast frequencies were 10-50% of B cells, compared with less than 1% in healthy individuals. Many of these proliferating plasmablasts were IgG-positive, and this finding coincided with the presence of Ebola virus-specific IgG in the serum. Activated CD4 T cells ranged from 5 to 30%, compared with 1-2% in healthy controls. The most pronounced responses were seen in CD8 T cells, with over 50% of the CD8 T cells expressing markers of activation and proliferation. Taken together, these results suggest that all four patients developed robust immune responses during the acute phase of Ebola virus infection, a finding that would not have been predicted based on our current assumptions about the highly immunosuppressive nature of Ebola virus. Also, quite surprisingly, we found sustained immune activation after the virus was cleared from the plasma, observed most strikingly in the persistence of activated CD8 T cells, even 1 mo after the patients' discharge from the hospital. These results suggest continued antigen stimulation after resolution of the disease. From these convalescent time points, we identified CD4 and CD8 T-cell responses to several Ebola virus proteins, most notably the viral nucleoprotein. Knowledge of the viral proteins targeted by T cells during natural infection should be useful in designing vaccines against Ebola virus.

  13. Infection of human thymocytes by Epstein-Barr virus.

    Science.gov (United States)

    Watry, D; Hedrick, J A; Siervo, S; Rhodes, G; Lamberti, J J; Lambris, J D; Tsoukas, C D

    1991-04-01

    The Epstein-Barr Virus (EBV) causes infectious mononucleosis, and has been strongly associated with certain human cancers. The virus is thought to exclusively bind to B lymphocytes and epithelial cells via receptors (CR2/CD21) that also interact with fragments of the third component of complement (C3). Recent evidence, however, has challenged this belief. We have used two-color immunofluorescence analysis using biotin-conjugated EBV and streptavidin-phycoerythrin along with fluorescein-conjugated anti-T cell antibodies and demonstrated that CD1-positive, CD3-dull (immature) human thymocytes express functional EBV receptors. In four replicate experiments, the binding of EBV to thymocytes ranged between 8 and 18%. This interaction is specific as evidenced by inhibition with nonconjugated virus, anti-CR2 antibodies, aggregated C3, and an antibody to the gp350 viral glycoprotein that the virus uses to bind to CR2. EBV can infect the thymocytes as evaluated by the presence of episomal EBV-DNA in thymocytes that had been incubated with the virus as short as 12 days or as long as 6 weeks. Episomal DNA analysis was performed by Southern blotting with a EBV-DNA probe that hybridizes to the first internal reiteration of the viral DNA. The presence of the EBV genome is also supported by the detection of EBV nuclear antigen 1 in infected thymocytes, assessed by Western blotting with EBV-immune sera. The EBV infection is specific as determined by blocking experiments using anti-CR2 and anti-gp350 antibodies. Finally, virus infection of thymocytes can act synergistically along with interleukin 2 and induce a lymphokine-dependent cellular proliferation. In view of previously reported cases of EBV-positive human T cell lymphomas, the possibility is raised that EBV may be involved in cancers of T lymphocytes that have not been previously appreciated. PMID:1706754

  14. Differential sensitivity of bat cells to infection by enveloped RNA viruses: coronaviruses, paramyxoviruses, filoviruses, and influenza viruses.

    Directory of Open Access Journals (Sweden)

    Markus Hoffmann

    Full Text Available Bats (Chiroptera host major human pathogenic viruses including corona-, paramyxo, rhabdo- and filoviruses. We analyzed six different cell lines from either Yinpterochiroptera (including African flying foxes and a rhinolophid bat or Yangochiroptera (genera Carollia and Tadarida for susceptibility to infection by different enveloped RNA viruses. None of the cells were sensitive to infection by transmissible gastroenteritis virus (TGEV, a porcine coronavirus, or to infection mediated by the Spike (S protein of SARS-coronavirus (SARS-CoV incorporated into pseudotypes based on vesicular stomatitis virus (VSV. The resistance to infection was overcome if cells were transfected to express the respective cellular receptor, porcine aminopeptidase N for TGEV or angiotensin-converting enzyme 2 for SARS-CoV. VSV pseudotypes containing the S proteins of two bat SARS-related CoV (Bg08 and Rp3 were unable to infect any of the six tested bat cell lines. By contrast, viral pseudotypes containing the surface protein GP of Marburg virus from the family Filoviridae infected all six cell lines though at different efficiency. Notably, all cells were sensitive to infection by two paramyxoviruses (Sendai virus and bovine respiratory syncytial virus and three influenza viruses from different subtypes. These results indicate that bat cells are more resistant to infection by coronaviruses than to infection by paramyxoviruses, filoviruses and influenza viruses. Furthermore, these results show a receptor-dependent restriction of the infection of bat cells by CoV. The implications for the isolation of coronaviruses from bats are discussed.

  15. Zika virus infection in French Polynesia

    OpenAIRE

    Jouannic, Jean-Marie; Friszer, Stephanie; Leparc-Goffart, Isabelle; Garel, Catherine; Eyrolle-Guignot, Dominique

    2016-01-01

    International audience On Feb 1, WHO issued an alert1 on the potential fetal consequences of the Zika virus outbreak after the Brazilian authorities reported an abnormal increase in the number of cases of neonates born with microcephaly.2 Although no causal link could be clearly established, circumstantial evidence was considered worrisome enough for several countries to discourage pregnant women from travelling to Central and South America.3

  16. Identification of a pegivirus (GB virus-like virus) that infects horses

    DEFF Research Database (Denmark)

    Kapoor, Amit; Simmonds, Peter; Cullen, John M;

    2013-01-01

    The recent identification of nonprimate hepaciviruses in dogs and then in horses prompted us to look for pegiviruses (GB virus-like viruses) in these species. Although none were detected in canines, we found widespread natural infection of horses by a novel pegivirus. Unique genomic features...... and phylogenetic analyses confirmed that the tentatively named equine pegivirus (EPgV) represents a novel species within the Pegivirus genus. We also determined that EPgV causes persistent viremia whereas its clinical significance is undetermined....

  17. Canine distemper virus infection in a lesser grison (Galictis cuja): first report and virus phylogeny

    OpenAIRE

    Jane Megid; Teixeira, Carlos R; Adriana Cortez; Heinemann, Marcos B; Antunes, João M.A.P.; Felipe Fornazari; Fabricio B. Rassy; Richtzenhain, Leonardo J

    2013-01-01

    Infectious diseases in wild animals have been increasing as a result of their habitat alterations and closer contact with domestic animals. Canine distemper virus (CDV) has been reported in several species of wild carnivores, presenting a threat to wildlife conservation. We described the first case of canine distemper virus infection in lesser grison (Galictis cuja). A free-ranging individual, with no visible clinical sigs, presented sudden death after one day in captivity. Molecular diagnosi...

  18. Atypical Presentations of Respiratory Syncytial Virus Infection; Case series

    Directory of Open Access Journals (Sweden)

    Nawal Al-Maskari

    2016-02-01

    Full Text Available The respiratory syncytial virus (RSV usually causes a lower respiratory tract infection in affected patients. RSV has also been infrequently linked to extrapulmonary diseases in children. We report four children who had unusually severe clinical manifestations of RSV infections requiring critical care admission. These patients presented to the Royal Hospital, Muscat, Oman, in December 2013 with acute necrotising encephalopathy (ANE, acute fulminant hepatic failure with encephalopathy, pneumatoceles and croup. A unique presentation of ANE has not previously been reported in association with an RSV infection. All patients had a positive outcome and recovered fully with supportive management.

  19. Association of hepatitis C virus infection and diabetes

    Institute of Scientific and Technical Information of China (English)

    Samir Rouabhia; Rachid Malek; Hocine Bounecer

    2009-01-01

    Epidemiologic studies have suggested a relation between hepatitis C virus (HCV) infection and diabetes mellitus. HCV infection is emerging as a metabolic disease, and diabetes mellitus as a risk factor for HCV infection. However, some data on the prevalence of antibodies to HCV in patients with diabetes are conflicting. These seroprevalence data should be interpreted with caution. Some potential bias may occur in those clinic-based studies that target a specific disease group. In this letter we explain some reasons for these conflicting studies.

  20. Clinical, Pathological and Immunological Aspects of Transplacental PRRS Virus Infection

    DEFF Research Database (Denmark)

    Nielsen, Jens

    2011-01-01

    PRRSV in the previously unaffected Danish pig population. Acute PRRS like disease was observed in non-vaccinated as well as in vaccinated herds, and it was demonstrated that the vaccine strain had reverted to virulence. By experimental infection of late term pregnant sows, we demonstrated that a field...... isolate of PRRS vaccine-derived virus (VDV) could cause disease in swine consistent with PRRS, thus confirming the etiological role of VDV. Since the complex pathology following in utero infection with PRRSV indicates impairment of the immune system of congenitally infected pigs, we studied various aspect...

  1. Crosstalk between innate and adaptive immunity inhepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Hepatitis B virus (HBV) infection is a major public health problem worldwide. HBV is not directly cytotoxic toinfected hepatocytes; the clinical outcome of infectionresults from complicated interactions between the virusand the host immune system. In acute HBV infection,initiation of a broad, vigorous immune response is responsiblefor viral clearance and self-limited inflammatoryliver disease. Effective and coordinated innate andadaptive immune responses are critical for viral clearanceand the development of long-lasting immunity. Chronichepatitis B patients fail to mount efficient innate andadaptive immune responses to the virus. In particular,HBV-specific cytotoxic T cells, which are crucial for HBVclearance, are hyporesponsiveness to HBV infection.Accumulating experimental evidence obtained fromthe development of animal and cell line models hashighlighted the importance of innate immunity in theearly control of HBV spread. The virus has evolvedimmune escape strategies, with higher HBV loads andHBV protein concentrations associated with increasingimpairment of immune function. Therefore, treatmentof HBV infection requires inhibition of HBV replicationand protein expression to restore the suppressedhost immunity. Complicated interactions exist notonly between innate and adaptive responses, but alsoamong innate immune cells and different components ofadaptive responses. Improved insight into these complexinteractions are important in designing new therapeuticstrategies for the treatment HBV infection. In thisreview, we summarize the current knowledge regardingthe cross-talk between the innate and adaptive immuneresponses and among different immunocytes in HBVinfection.

  2. Ultrastructural description of rabies virus infection in cultured sensory neurons

    Directory of Open Access Journals (Sweden)

    Myriam L Velandia

    2007-06-01

    Full Text Available Primary cultures were made from adult mouse spinal ganglia for depicting an ultrastructural description of rabies virus (RABV infection in adult mouse sensory neuron cultures; they were infected with rabies virus for 24, 36, and 48 h. The monolayers were processed for transmission electron microscopy and immunochemistry studies at the end of each period. As previously reported, sensory neurons showed great susceptibility to infection by RABV; however, in none of the periods evaluated were assembled virions observed in the cytoplasm or seen to be associated with the cytoplasmic membrane. Instead, fibril matrices of aggregated ribonucleoprotein were detected in the cytoplasm. When infected culture lysate were inoculated into normal animals via intra-cerebral route it was observed that these animals developed clinical symptoms characteristic of infection and transmission electron microscopy revealed assembled virions in the cerebral cortex and other areas of the brain. Sensory neurons infected in vitro by RABV produced a large amount of unassembled viral ribonucleoprotein. However, this intracellular material was able to produce infection and virions on being intra-cerebrally inoculated. It can thus be suggested that the lack of intracellular assembly in sensory neurons forms part of an efficient dissemination strategy.

  3. Undetectable hepatitis C virus RNA during syphilis infection in two HIV/HCV-co-infected patients

    DEFF Research Database (Denmark)

    Salado-Rasmussen, Kirsten; Knudsen, Andreas; Krarup, Henrik Bygum;

    2014-01-01

    BACKGROUND: Treponema pallidum, the causative agent of syphilis, elicits a vigorous immune response in the infected host. This study sought to describe the impact of syphilis infection on hepatitis C virus (HCV) RNA levels in patients with HIV and chronic HCV infection. METHODS: Patients...... with chronic HIV/HCV and syphilis co-infection were identified by their treating physicians from 1 October 2010 to 31 December 2013. Stored plasma samples obtained before, during, and after syphilis infection were analysed for interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, tumour necrosis factor alpha (TNF......-α), interferon gamma (IFN-γ), and IFN-γ-inducible protein 10 kDa (IP-10). RESULTS: Undetectable HCV RNA at the time of early latent syphilis infection was observed in 2 patients with HIV and chronic HCV infection. After treatment of the syphilis infection, HCV RNA levels increased again in patient 1, whereas...

  4. THE MOLECULAR EVOLUTION OF THE MOST DANGEROUS EMERGING VIRUS INFECTIONS

    Directory of Open Access Journals (Sweden)

    Popov NN

    2016-03-01

    barriers and infect new hosts. Really, many recently emerged human diseases are caused by viruses that display active recombination or reassortment. The continual shuffling of genes of influenza A represents a example of the key role of reassortment for the new virus emergence. Available data demonstrate the possible origin of SARS-CoV from recombination of different bat SL-CoVs viruses strains. However in other cases the emergence of a specific virus cannot be directly attributed to its ability to recombine. For example, although SIV recombines at a high rate in natural reservoirs, there is no evidence that recombination assisted the cross-species transfer of the virus from the chimpanzee into humans. But mutagenesis and recombination actively shape the further molecular history of HIV in humans. Also it is not proved that recombination precede the cross-species jump of the Ebola virus. In summary, the available data suggest that although recombination, reassortment and mutagenesis is sometimes directly involved to the process of cross-species transmission, it is not a necessary precursor to successful viral emergence. Further investigations are required to reveal the role of genetic change in the history of virus emergence. We believe that comprehensive description of molecular evolution of new viruses has led to a better understanding of the causes and predictability of infection emergence.

  5. Hendra virus infection dynamics in Australian fruit bats.

    Directory of Open Access Journals (Sweden)

    Hume Field

    Full Text Available Hendra virus is a recently emerged zoonotic agent in Australia. Since first described in 1994, the virus has spilled from its wildlife reservoir (pteropid fruit bats, or 'flying foxes' on multiple occasions causing equine and human fatalities. We undertook a three-year longitudinal study to detect virus in the urine of free-living flying foxes (a putative route of excretion to investigate Hendra virus infection dynamics. Pooled urine samples collected off plastic sheets placed beneath roosting flying foxes were screened for Hendra virus genome by quantitative RT-PCR, using a set of primers and probe derived from the matrix protein gene. A total of 1672 pooled urine samples from 67 sampling events was collected and tested between 1 July 2008 and 30 June 2011, with 25% of sampling events and 2.5% of urine samples yielding detections. The proportion of positive samples was statistically associated with year and location. The findings indicate that Hendra virus excretion occurs periodically rather than continuously, and in geographically disparate flying fox populations in the state of Queensland. The lack of any detection in the Northern Territory suggests prevalence may vary across the range of flying foxes in Australia. Finally, our findings suggest that flying foxes can excrete virus at any time of year, and that the apparent seasonal clustering of Hendra virus incidents in horses and associated humans (70% have occurred June to October reflects factors other than the presence of virus. Identification of these factors will strengthen risk minimization strategies for horses and ultimately humans.

  6. Proteasome Inhibition Suppresses Dengue Virus Egress in Antibody Dependent Infection.

    Science.gov (United States)

    Choy, Milly M; Zhang, Summer L; Costa, Vivian V; Tan, Hwee Cheng; Horrevorts, Sophie; Ooi, Eng Eong

    2015-11-01

    The mosquito-borne dengue virus (DENV) is a cause of significant global health burden, with an estimated 390 million infections occurring annually. However, no licensed vaccine or specific antiviral treatment for dengue is available. DENV interacts with host cell factors to complete its life cycle although this virus-host interplay remains to be fully elucidated. Many studies have identified the ubiquitin proteasome pathway (UPP) to be important for successful DENV production, but how the UPP contributes to DENV life cycle as host factors remains ill defined. We show here that proteasome inhibition decouples infectious virus production from viral RNA replication in antibody-dependent infection of THP-1 cells. Molecular and imaging analyses in β-lactone treated THP-1 cells suggest that proteasome function does not prevent virus assembly but rather DENV egress. Intriguingly, the licensed proteasome inhibitor, bortezomib, is able to inhibit DENV titers at low nanomolar drug concentrations for different strains of all four serotypes of DENV in primary monocytes. Furthermore, bortezomib treatment of DENV-infected mice inhibited the spread of DENV in the spleen as well as the overall pathological changes. Our findings suggest that preventing DENV egress through proteasome inhibition could be a suitable therapeutic strategy against dengue. PMID:26565697

  7. Proteasome Inhibition Suppresses Dengue Virus Egress in Antibody Dependent Infection.

    Directory of Open Access Journals (Sweden)

    Milly M Choy

    2015-11-01

    Full Text Available The mosquito-borne dengue virus (DENV is a cause of significant global health burden, with an estimated 390 million infections occurring annually. However, no licensed vaccine or specific antiviral treatment for dengue is available. DENV interacts with host cell factors to complete its life cycle although this virus-host interplay remains to be fully elucidated. Many studies have identified the ubiquitin proteasome pathway (UPP to be important for successful DENV production, but how the UPP contributes to DENV life cycle as host factors remains ill defined. We show here that proteasome inhibition decouples infectious virus production from viral RNA replication in antibody-dependent infection of THP-1 cells. Molecular and imaging analyses in β-lactone treated THP-1 cells suggest that proteasome function does not prevent virus assembly but rather DENV egress. Intriguingly, the licensed proteasome inhibitor, bortezomib, is able to inhibit DENV titers at low nanomolar drug concentrations for different strains of all four serotypes of DENV in primary monocytes. Furthermore, bortezomib treatment of DENV-infected mice inhibited the spread of DENV in the spleen as well as the overall pathological changes. Our findings suggest that preventing DENV egress through proteasome inhibition could be a suitable therapeutic strategy against dengue.

  8. Liver histology in co-infection of hepatitis C virus (HCV and Hepatitis G virus (HGV

    Directory of Open Access Journals (Sweden)

    STRAUSS Edna

    2002-01-01

    Full Text Available As little is known about liver histology in the co-infection of hepatitis C virus (HCV and hepatitis G virus (HGV, HGV RNA was investigated in 46 blood donors with hepatitis C, 22 of them with liver biopsy: co-infection HCV / HGV (n = 6 and HCV isolated infection (n = 16. Besides staging and grading of inflammation at portal, peri-portal and lobular areas (Brazilian Consensus, the fibrosis progression index was also calculated. All patients had no symptoms or signs of liver disease and prevalence of HGV / HCV co-infection was 15.2%. Most patients had mild liver disease and fibrosis progression index, calculated only in patients with known duration of infection, was 0.110 for co-infection and 0.130 for isolated HCV infection, characterizing these patients as "slow fibrosers". No statistical differences could be found between the groups, although a lesser degree of inflammation was always present in co-infection. In conclusion co-infection HCV / HGV does not induce a more aggressive liver disease, supporting the hypothesis that HGV is not pathogenic.

  9. Modelling Virus and Antibody Dynamics during Dengue Virus Infection Suggests a Role for Antibody in Virus Clearance.

    Directory of Open Access Journals (Sweden)

    Hannah E Clapham

    2016-05-01

    Full Text Available Dengue is an infection of increasing global importance, yet uncertainty remains regarding critical aspects of its virology, immunology and epidemiology. One unanswered question is how infection is controlled and cleared during a dengue infection. Antibody is thought to play a role, but little past work has examined the kinetics of both virus and antibody during natural infections. We present data on multiple virus and antibody titres measurements recorded sequentially during infection from 53 Vietnamese dengue patients. We fit mechanistic mathematical models of the dynamics of viral replication and the host immune response to these data. These models fit the data well. The model with antibody removing virus fits the data best, but with a role suggested for ADCC or other infected cell clearance mechanisms. Our analysis therefore shows that the observed viral and antibody kinetics are consistent with antibody playing a key role in controlling viral replication. This work gives quantitative insight into the relationship between antibody levels and the efficiency of viral clearance. It will inform the future development of mechanistic models of how vaccines and antivirals might modify the course of natural dengue infection.

  10. Tick-borne encephalitis virus infection in humans

    Directory of Open Access Journals (Sweden)

    Hrnjaković-Cvjetković Ivana

    2016-01-01

    Full Text Available Introduction. Tick-borne meningoencephalitis virus is a flavivirus that causes the most important vector-borne central nervous system infection in many countries of Europe and Asia. There are three subtypes of tick-borne encephalitis virus: European, Siberian and the Far-Eastern subtype. Transmission. In endemic areas, the virus remains in transmissive cycles between Ixodes ticks and small rodents. Clinical picture. In most cases (70−98% infection goes asymptomatically. In about one-third of meningitis cases, meningoencephalitis or meningomyelitis is developed. Postencephalytic syndrome may be the complication of the infection, presenting with neurological symptoms. Diagnosis. Etiologic diagnosis of tick-borne meningoencephalitis is only made on basis of laboratory analyses. Reverse transcription-polymerase chain reaction is used for determining the presence of virus in the blood and cerebrospinal fluid. Antibodies in blood and cerebrospinal fluid can be detected by serological tests. Prevention. The most efficient way to control this potentially severe disease with possible serious long-term consequences is vaccination. It should be recommended to persons who live or travel to endemic areas. Conclusion. In Serbia, tick-borne encephalitis virus infection belongs to the list of reportable diseases; however, there are no reported cases because the diagnostics is not performed routinely. We believe that the significance of this zoonosis must be examined in our country and some of its parts because of preliminary positive serological findings found out in Vojvodina as well as because of reported cases in neighboring countries such as Hungary and Croatia and its worldwide distribution.

  11. Characterization of Lethal Zika Virus Infection in AG129 Mice.

    Directory of Open Access Journals (Sweden)

    Matthew T Aliota

    2016-04-01

    Full Text Available Mosquito-borne Zika virus (ZIKV typically causes a mild and self-limiting illness known as Zika fever, which often is accompanied by maculopapular rash, headache, and myalgia. During the current outbreak in South America, ZIKV infection during pregnancy has been hypothesized to cause microcephaly and other diseases. The detection of ZIKV in fetal brain tissue supports this hypothesis. Because human infections with ZIKV historically have remained sporadic and, until recently, have been limited to small-scale epidemics, neither the disease caused by ZIKV nor the molecular determinants of virulence and/or pathogenicity have been well characterized. Here, we describe a small animal model for wild-type ZIKV of the Asian lineage.Using mice deficient in interferon α/β and Ɣ receptors (AG129 mice, we report that these animals were highly susceptible to ZIKV infection and disease, succumbing within seven to eight days. Rapid viremic dissemination was observed in visceral organs and brain; but only was associated with severe pathologies in the brain and muscle. Finally, these results were consistent across challenge routes, age of mice, and inoculum doses. These data represent a mouse model for ZIKV that is not dependent on adapting ZIKV to intracerebral passage in mice.Foot pad injection of AG129 mice with ZIKV represents a biologically relevant model for studying ZIKV infection and disease development following wild-type virus inoculation without the requirement for adaptation of the virus or intracerebral delivery of the virus. This newly developed Zika disease model can be exploited to identify determinants of ZIKV virulence and reveal molecular mechanisms that control the virus-host interaction, providing a framework for rational design of acute phase therapeutics and for vaccine efficacy testing.

  12. Characterization of Lethal Zika Virus Infection in AG129 Mice

    Science.gov (United States)

    Walker, Emma C.; Larkin, Katrina E.; Camacho, Erwin; Osorio, Jorge E.

    2016-01-01

    Background Mosquito-borne Zika virus (ZIKV) typically causes a mild and self-limiting illness known as Zika fever, which often is accompanied by maculopapular rash, headache, and myalgia. During the current outbreak in South America, ZIKV infection during pregnancy has been hypothesized to cause microcephaly and other diseases. The detection of ZIKV in fetal brain tissue supports this hypothesis. Because human infections with ZIKV historically have remained sporadic and, until recently, have been limited to small-scale epidemics, neither the disease caused by ZIKV nor the molecular determinants of virulence and/or pathogenicity have been well characterized. Here, we describe a small animal model for wild-type ZIKV of the Asian lineage. Methodology/Principal Findings Using mice deficient in interferon α/β and Ɣ receptors (AG129 mice), we report that these animals were highly susceptible to ZIKV infection and disease, succumbing within seven to eight days. Rapid viremic dissemination was observed in visceral organs and brain; but only was associated with severe pathologies in the brain and muscle. Finally, these results were consistent across challenge routes, age of mice, and inoculum doses. These data represent a mouse model for ZIKV that is not dependent on adapting ZIKV to intracerebral passage in mice. Conclusions/Significance Foot pad injection of AG129 mice with ZIKV represents a biologically relevant model for studying ZIKV infection and disease development following wild-type virus inoculation without the requirement for adaptation of the virus or intracerebral delivery of the virus. This newly developed Zika disease model can be exploited to identify determinants of ZIKV virulence and reveal molecular mechanisms that control the virus-host interaction, providing a framework for rational design of acute phase therapeutics and for vaccine efficacy testing. PMID:27093158

  13. Virus Infection and Titration of SARS-CoV in Mouse Lung

    OpenAIRE

    Fett, Craig; Zhao, Jincun; Perlman, Stanley

    2014-01-01

    Two critical steps when investigating an animal model of a virus infection are consistently successfully infecting animals and accurately determining viral titers in tissue throughout the course of infection. Here we discuss in detail how to infect mice with SARS-CoV and then quantify the titer of virus in the lung.

  14. Serological evidence of Ebola virus infection in Indonesian orangutans.

    Directory of Open Access Journals (Sweden)

    Chairul A Nidom

    Full Text Available Ebola virus (EBOV and Marburg virus (MARV belong to the family Filoviridae and cause severe hemorrhagic fever in humans and nonhuman primates. Despite the discovery of EBOV (Reston virus in nonhuman primates and domestic pigs in the Philippines and the serological evidence for its infection of humans and fruit bats, information on the reservoirs and potential amplifying hosts for filoviruses in Asia is lacking. In this study, serum samples collected from 353 healthy Bornean orangutans (Pongo pygmaeus in Kalimantan Island, Indonesia, during the period from December 2005 to December 2006 were screened for filovirus-specific IgG antibodies using a highly sensitive enzyme-linked immunosorbent assay (ELISA with recombinant viral surface glycoprotein (GP antigens derived from multiple species of filoviruses (5 EBOV and 1 MARV species. Here we show that 18.4% (65/353 and 1.7% (6/353 of the samples were seropositive for EBOV and MARV, respectively, with little cross-reactivity among EBOV and MARV antigens. In these positive samples, IgG antibodies to viral internal proteins were also detected by immunoblotting. Interestingly, while the specificity for Reston virus, which has been recognized as an Asian filovirus, was the highest in only 1.4% (5/353 of the serum samples, the majority of EBOV-positive sera showed specificity to Zaire, Sudan, Cote d'Ivoire, or Bundibugyo viruses, all of which have been found so far only in Africa. These results suggest the existence of multiple species of filoviruses or unknown filovirus-related viruses in Indonesia, some of which are serologically similar to African EBOVs, and transmission of the viruses from yet unidentified reservoir hosts into the orangutan populations. Our findings point to the need for risk assessment and continued surveillance of filovirus infection of human and nonhuman primates, as well as wild and domestic animals, in Asia.

  15. Gene-gun DNA vaccination aggravates respiratory syncytial virus-induced pneumonitis

    DEFF Research Database (Denmark)

    Bartholdy, Christina; Olszewska, Wieslawa; Stryhn, Anette;

    2004-01-01

    A CD8+ T-cell memory response to respiratory syncytial virus (RSV) was generated by using a DNA vaccine construct encoding the dominant Kd-restricted epitope from the viral transcription anti-terminator protein M2 (M2(82-90)), linked covalently to human beta2-microglobulin (beta2m). Cutaneous gene...... elicited with recombinant vaccinia virus expressing the complete RSV M2 protein, but stronger than those induced by a similar DNA construct without the beta2m gene. DNA vaccination led to enhanced pulmonary disease after RSV challenge, with increased weight loss and cell recruitment to the lung. Depletion...... of CD8+ T cells reduced, but did not abolish, enhancement of disease. Mice vaccinated with a construct encoding a class I-restricted lymphocytic choriomeningitis virus epitope and beta2m suffered more severe weight loss after RSV infection than unvaccinated RSV-infected mice, although RSV-specific CD8...

  16. Molecular Biology and Infection of Hepatitis E Virus

    Science.gov (United States)

    Nan, Yuchen; Zhang, Yan-Jin

    2016-01-01

    Hepatitis E virus (HEV) is a viral pathogen transmitted primarily via fecal-oral route. In humans, HEV mainly causes acute hepatitis and is responsible for large outbreaks of hepatitis across the world. The case fatality rate of HEV-induced hepatitis ranges from 0.5 to 3% in young adults and up to 30% in infected pregnant women. HEV strains infecting humans are classified into four genotypes. HEV strains from genotypes 3 and 4 are zoonotic, whereas those from genotypes 1 and 2 have no known animal reservoirs. Recently, notable progress has been accomplished for better understanding of HEV biology and infection, such as chronic HEV infection, in vitro cell culture system, quasi-enveloped HEV virions, functions of the HEV proteins, mechanism of HEV antagonizing host innate immunity, HEV pathogenesis and vaccine development. However, further investigation on the cross-species HEV infection, host tropism, vaccine efficacy, and HEV-specific antiviral strategy is still needed. This review mainly focuses on molecular biology and infection of HEV and offers perspective new insight of this enigmatic virus. PMID:27656178

  17. Epstein-Barr Virus Infection with Acute Pancreatitis Associated with Cholestatic Hepatitis

    OpenAIRE

    Kang, Seok-Jin; Yoon, Ka-Hyun; Hwang, Jin-Bok

    2013-01-01

    Infection-induced acute hepatitis complicated with acute pancreatitis is associated with hepatitis A virus, hepatitis B virus or hepatitis E virus. Although rare, Epstein-Barr virus (EBV) infection should be considered also in the differential diagnosis if the patient has acute hepatitis combined with pancreatitis. We report a case of EBV infection with cholestatic hepatitis and pancreatitis with review of literature. An 11-year-old female was admitted due to 1-day history of abdominal pain a...

  18. High Prevalence of Hepatitis B Virus Markers in Romanian Adolescents With Human Immunodeficiency Virus Infection

    Directory of Open Access Journals (Sweden)

    Ruta Simona

    2005-03-01

    Full Text Available Abstract Background We evaluated the frequency of hepatitis coinfection in Romanian adolescents who were diagnosed with human immunodeficiency virus (HIV infection prior to 1995. Methods One hundred sixty-one adolescents (13–18 years of age with symptomatic HIV infection, but without signs of hepatic dysfunction, and 356 age-matched, HIV-uninfected controls underwent laboratory testing for markers of parenterally acquired hepatitis virus infection. Results Seventy-eight percent of HIV-infected adolescents had markers of past or present hepatitis B virus (HBV infection, as compared with 32% of controls (P = .0001. The prevalence of HBV replicative markers was more than 5-fold higher in HIV-infected adolescents as compared with controls: 43.4% vs 7.9% (P = .0001, respectively, for hepatitis B surface antigen (HBsAg; and 11.2% vs 2.2% (P = .0001, respectively, for hepatitis B e antigen (HBeAg. The prevalence of HBsAg chronic carriers and the presence of HBV replicative markers was significantly higher in patients with immunologically defined AIDS (CD4+ cell counts P = .02 for HBsAg and 22.8% vs 5.7%, (P = .002 for HBV DNA. After 1 year of follow-up, the proportion of those who cleared the HBeAg was considerably lower in severely immunosuppressed coinfected patients: 4.7% vs 37.1% (P = .003. Four additional HIV-infected adolescents became HBsAg-positive over the term of follow-up (incidence rate, 24.9/1000 person-years, despite a record of immunization against hepatitis B. Conclusion A substantial percentage of HIV-infected and HIV-uninfected Romanian adolescents have evidence of past or present HBV infection. In HIV-infected adolescents, the degree of immunosuppression is correlated with persistence of HBV replicative markers, even in the absence of clinical or biochemical signs of liver disease.

  19. Begomoviruses infecting weeds in Cuba: increased host range and a novel virus infecting Sida rhombifolia.

    Science.gov (United States)

    Fiallo-Olivé, Elvira; Navas-Castillo, Jesús; Moriones, Enrique; Martínez-Zubiaur, Yamila

    2012-01-01

    As a result of surveys conducted during the last few years to search for wild reservoirs of begomoviruses in Cuba, we detected a novel bipartite begomovirus, sida yellow mottle virus (SiYMoV), infecting Sida rhombifolia plants. The complete genome sequence was obtained, showing that DNA-A was 2622 nucleotides (nt) in length and that it was most closely related (87.6% nucleotide identity) to DNA-A of an isolate of sida golden mosaic virus (SiGMV) that infects snap beans (Phaseolus vulgaris) in Florida. The DNA-B sequence was 2600 nt in length and shared the highest nucleotide identity (75.1%) with corchorus yellow spot virus (CoYSV). Phylogenetic relationship analysis showed that both DNA components of SiYMoV were grouped in the Abutilon clade, along with begomoviruses from Florida and the Caribbean islands. We also present here the complete nucleotide sequence of a novel strain of sida yellow vein virus found infecting Malvastrum coromandelianum and an isolate of euphorbia mosaic virus that was found for the first time infecting Euphorbia heterophylla in Cuba.

  20. Immunoprophylaxis of hepatitis B virus infection

    OpenAIRE

    Joshi N; Kumar A

    2001-01-01

    Hepatitis-B infection is a global health problem. The spectrum of the disease is highly variable ranging from mild disease to chronic liver diseases including hepatocellular carcinoma. There are approximately 350 million chronic Hepatitis-B surface antigen (HBsAg) carriers in the world. Till date there is no effective therapy against this disease. Hence, prevention of the disease through vaccination is the only means to control the disease. Passive immunization is recommended for certain acci...

  1. Suppressors of cytokine signaling 1 and 3 are up-regulated in brain resident cells in response to virus induced inflammation of the CNS via at least two distinctive pathways

    DEFF Research Database (Denmark)

    Steffensen, Maria Abildgaard; Fenger, Christina; Christensen, Jeanette Erbo;

    2014-01-01

    Suppressors of cytokine signaling (SOCS) proteins are intracellular proteins that inhibit cytokine signaling in a variety of cell types. A number of viral infections have been associated with SOCS up-regulation; however, not much is known about the mechanisms regulating SOCS expression during viral......-cytolytic and a cytolytic virus induce marked up-regulation of SOCS1 and-3 expression. Notably, the kinetics of the observed up-regulation follows that of activity within pro-inflammatory signalling pathways and, interestingly, type II IFN, which is also a key inducer of inflammatory mediators, seems to be essential...... underlie a virus induced up-regulation of SOCS in the CNS. We found that i.c. infection with either lymphocytic choriomeningitis virus (LCMV) or yellow fever virus (YF) results in gradual up-regulation of SOCS1/3 mRNA expression peaking at day 7 post infection (p.i.). In the LCMV model, SOCS m...

  2. Infection Functions for Virus Propagation in Computer Networks: An Empirical Study

    Institute of Scientific and Technical Information of China (English)

    YUAN Hua; WU Junjie; CHEN Guoqing

    2009-01-01

    There has been an increasing amount of interest in modeling virus propagation in recent years. However, the group-based infection mechanism of computer viruses is not well understood and the selec-tion of infection function in virus propagation modeling has not been well studied. This paper describes a point-to-group (P2G) infection mode to describe" virus propagation in networks with information sharing groups. Simulations compare the constant infection and I-type infection functions with the new E-type infec-lion function in the small-world-network environment. The simulation results show that the E-type infection function shows supedor performances to that of the traditional I-type infection function in modeling the P2G virus infection mechanism and the Ⅰ-type infection function shows better performance in modeling the ran-dom infection mechanism.

  3. Nipah virus infection and glycoprotein targeting in endothelial cells

    Directory of Open Access Journals (Sweden)

    Maisner Andrea

    2010-11-01

    Full Text Available Abstract Background The highly pathogenic Nipah virus (NiV causes fatal respiratory and brain infections in animals and humans. The major hallmark of the infection is a systemic endothelial infection, predominantly in the CNS. Infection of brain endothelial cells allows the virus to overcome the blood-brain-barrier (BBB and to subsequently infect the brain parenchyma. However, the mechanisms of NiV replication in endothelial cells are poorly elucidated. We have shown recently that the bipolar or basolateral expression of the NiV surface glycoproteins F and G in polarized epithelial cell layers is involved in lateral virus spread via cell-to-cell fusion and that correct sorting depends on tyrosine-dependent targeting signals in the cytoplasmic tails of the glycoproteins. Since endothelial cells share many characteristics with epithelial cells in terms of polarization and protein sorting, we wanted to elucidate the role of the NiV glycoprotein targeting signals in endothelial cells. Results As observed in vivo, NiV infection of endothelial cells induced syncytia formation. The further finding that infection increased the transendothelial permeability supports the idea of spread of infection via cell-to-cell fusion and endothelial cell damage as a mechanism to overcome the BBB. We then revealed that both glycoproteins are expressed at lateral cell junctions (bipolar, not only in NiV-infected primary endothelial cells but also upon stable expression in immortalized endothelial cells. Interestingly, mutation of tyrosines 525 and 542/543 in the cytoplasmic tail of the F protein led to an apical redistribution of the protein in endothelial cells whereas tyrosine mutations in the G protein had no effect at all. This fully contrasts the previous results in epithelial cells where tyrosine 525 in the F, and tyrosines 28/29 in the G protein were required for correct targeting. Conclusion We conclude that the NiV glycoprotein distribution is responsible for

  4. Localization of influenza virus proteins to nuclear dot 10 structures in influenza virus-infected cells

    International Nuclear Information System (INIS)

    We studied influenza virus M1 protein by generating HeLa and MDCK cell lines that express M1 genetically fused to green fluorescent protein (GFP). GFP-M1 was incorporated into virions produced by influenza virus infected MDCK cells expressing the fusion protein indicating that the fusion protein is at least partially functional. Following infection of either HeLa or MDCK cells with influenza A virus (but not influenza B virus), GFP-M1 redistributes from its cytosolic/nuclear location and accumulates in nuclear dots. Immunofluorescence revealed that the nuclear dots represent nuclear dot 10 (ND10) structures. The colocalization of authentic M1, as well as NS1 and NS2 protein, with ND10 was confirmed by immunofluorescence following in situ isolation of ND10. These findings demonstrate a previously unappreciated involvement of influenza virus with ND10, a structure involved in cellular responses to immune cytokines as well as the replication of a rapidly increasing list of viruses

  5. Tomato bushy stunt virus (TBSV) infecting Lycopersicon esculentum.

    Science.gov (United States)

    Hafez, El Sayed E; Saber, Ghada A; Fattouh, Faiza A

    2010-01-01

    Tomato bushy stunt virus (TBSV) was detected in tomato crop (Lycopersicon esculentum) in Egypt with characteristic mosaic leaf deformation, stunting, and bushy growth symptoms. TBSV infection was confirmed serologically by ELISA and calculated incidence was 25.5%. Basic physicochemical properties of a purified TBSV Egh isolate were identical to known properties of tombusviruses of isometric 30-nm diameter particles, 41-kDa coat protein and the genome of approximately 4800 nt. This is the first TBSV isolate reported in Egypt. Cloning and partial sequencing of the isolate showed that it is more closely related to TBSV-P and TBSV-Ch than TBSV-Nf and TBSV-S strains of the virus. However, it is distinct from the above strains and could be a new strain of the virus which further confirms the genetic diversity of tombusviruses. PMID:21138066

  6. Simian varicella virus infection of rhesus macaques recapitulates essential features of varicella zoster virus infection in humans.

    Directory of Open Access Journals (Sweden)

    Ilhem Messaoudi

    2009-11-01

    Full Text Available Simian varicella virus (SVV, the etiologic agent of naturally occurring varicella in primates, is genetically and antigenically closely related to human varicella zoster virus (VZV. Early attempts to develop a model of VZV pathogenesis and latency in nonhuman primates (NHP resulted in persistent infection. More recent models successfully produced latency; however, only a minority of monkeys became viremic and seroconverted. Thus, previous NHP models were not ideally suited to analyze the immune response to SVV during acute infection and the transition to latency. Here, we show for the first time that intrabronchial inoculation of rhesus macaques with SVV closely mimics naturally occurring varicella (chickenpox in humans. Infected monkeys developed varicella and viremia that resolved 21 days after infection. Months later, viral DNA was detected only in ganglia and not in non-ganglionic tissues. Like VZV latency in human ganglia, transcripts corresponding to SVV ORFs 21, 62, 63 and 66, but not ORF 40, were detected by RT-PCR. In addition, as described for VZV, SVV ORF 63 protein was detected in the cytoplasm of neurons in latently infected monkey ganglia by immunohistochemistry. We also present the first in depth analysis of the immune response to SVV. Infected animals produced a strong humoral and cell-mediated immune response to SVV, as assessed by immunohistology, serology and flow cytometry. Intrabronchial inoculation of rhesus macaques with SVV provides a novel model to analyze viral and immunological mechanisms of VZV latency and reactivation.

  7. Host susceptibility to persistent hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    Ying-Li He; Ying-Ren Zhao; Shu-Lin Zhang; Shu-Mei Lin

    2006-01-01

    Genetic epidemiology researches such as twin studies, family-clustering of hepatitis B virus (HBV) infection studies and ethnic difference studies have provided the evidence that host genetic factors play an important role in determining the outcome of HBV infection. The opening questions include which human genes are important in infection and how to find them. Though a number of studies have sought genetic associations between HBV infection/persistence and gene polymorphisms, the candidate gene-based approach is clearly inadequate to fully explain the genetic basis of the disease. With the advent of new genetic markers and automated genotyping, genetic mapping can be conducted extremely rapid. This approach has been successful in some infectious diseases. Linkage analysis can find host genes susceptible to HBV and is of great clinical importance.

  8. Fracture risk in hepatitis C virus infected persons

    DEFF Research Database (Denmark)

    Hansen, Ann-Brit Eg; Omland, Lars Haukali; Krarup, Henrik;

    2014-01-01

    BACKGROUND & AIMS: The association between Hepatitis C virus (HCV)-infection and fracture risk is not well characterized. We compared fracture risk between HCV-seropositive (HCV-exposed) patients and the general population and between patients with cleared and chronic HCV-infection. METHODS......: Outcome measures were time to first fracture at any site, time to first low-energy and first non-low-energy (other) fracture in 12,013 HCV-exposed patients from the DANVIR cohort compared with a general population control cohort (n=60,065) matched by sex and age. Within DANVIR, 4500 patients with chronic...... HCV-infection and 2656 patients with cleared HCV-infection were studied. RESULTS: Compared with population controls, HCV-exposed patients had increased overall risk of fracture [adjusted incidence rate ratio (aIRR) 2.15, 95% Confidence Interval (CI) 2.03-2.28], increased risk of low-energy fracture (a...

  9. Characterisation of immunosuppression in rabbits after infection with myxoma virus.

    Science.gov (United States)

    Jeklova, Edita; Leva, Lenka; Matiasovic, Jan; Kovarcik, Kamil; Kudlackova, Hana; Nevorankova, Zora; Psikal, Ivan; Faldyna, Martin

    2008-05-25

    Myxoma virus (MXV) causes the systemic disease myxomatosis in the European rabbit. Despite many in vitro studies on the function of MXV immunomodulatory proteins and detailed molecular knowledge of virus, little is known about the dynamics of interaction of the virus with the integrated host-immune system during infection. In this study changes in haematological profile, changes in lymphocyte subset distribution and non-specific proliferation activity of lymphocytes from different lymphoid compartments on the 2nd, 4th, 6th, 9th and 11th day after experimental infection of rabbits with MXV strain Lausanne was characterised. The relationship between alterations of immune parameters and dynamic of virus dissemination through the body was investigated. Haematological changes included moderate leucopenia with significant lymphopenia, neutrophilia, monocytosis and eosinopenia. A decrease of T cells including CD4+ and CD8+ and increase of CD79alpha+ were observed in draining popliteal lymph node 4 days after virus inoculation. From day 6, comparable changes were seen in collateral popliteal lymph node, spleen and peripheral blood. From day 9, the mentioned lymphocyte subsets tended to reach their original state in all of these lymphocyte compartments except draining popliteal lymph node. In thymus, MXV infection affected mainly CD4+CD8+ double positive thymocytes. On the other hand, proliferation activity of lymphocytes determined by the proliferation assay with plant-derived mitogens was significantly reduced from day 4 or 6 and remained reduced until the end of experiment in all observed lymphoid organs. Presence of MXV in respective lymphoid compartments preceded changes in lymphocyte subset distribution or lymphocyte activity. PMID:18222052

  10. Demographics of natural oral infection of mosquitos by Venezuelan equine encephalitis virus.

    Science.gov (United States)

    Gutiérrez, Serafín; Thébaud, Gaël; Smith, Darci R; Kenney, Joan L; Weaver, Scott C

    2015-04-01

    The within-host diversity of virus populations can be drastically limited during between-host transmission, with primary infection of hosts representing a major constraint to diversity maintenance. However, there is an extreme paucity of quantitative data on the demographic changes experienced by virus populations during primary infection. Here, the multiplicity of cellular infection (MOI) and population bottlenecks were quantified during primary mosquito infection by Venezuelan equine encephalitis virus, an arbovirus causing neurological disease in humans and equids.

  11. Glomerular Diseases Associated with Hepatitis C Virus Infection

    Directory of Open Access Journals (Sweden)

    Miller Sara

    2000-01-01

    Full Text Available Renal diseases associated with hepatitis C virus (HCV infection are a significant problem for clinicians and diagnostic pathologists. A wide variety of disorders, including a spectrum of immune-complex glomerulonephritides, has been reported in association with hepatitis and cirrhosis caused by HCV. For some of these diseases, including membranoproliferative glomerulonephritis type I and cryoglobulinemic glomerulonephritis, plausible links between HCV and the glomerular pathology have been proposed. In other cases, the role of the virus in the pathogenesis of the renal disease is less certain. This communication catalogues the renal manifestations of HCV infection, providing clinical and pathological descriptions of the most prevalent disorders. Where available, evidence implicating HCV in the causation of the disorders is also discussed.

  12. In vivo models of hepatitis B and C virus infection.

    Science.gov (United States)

    Winer, Benjamin Y; Ding, Qiang; Gaska, Jenna M; Ploss, Alexander

    2016-07-01

    Globally, more than 500 million individuals are chronically infected with hepatitis B (HBV), delta (HDV), and/or C (HCV) viruses, which can result in severe liver disease. Mechanistic studies of viral persistence and pathogenesis have been hampered by the scarcity of animal models. The limited species and cellular host range of HBV, HDV, and HCV, which robustly infect only humans and chimpanzees, have posed challenges for creating such animal models. In this review, we will discuss the barriers to interspecies transmission and the progress that has been made in our understanding of the HBV, HDV, and HCV life cycles. Additionally, we will highlight a variety of approaches that overcome these barriers and thus facilitate in vivo studies of these hepatotropic viruses.

  13. Hepatitis B Virus Infection in Iran: Current Knowledge, Future Plans

    OpenAIRE

    Hossein Khedmat; Saeed Taheri

    2009-01-01

    Dear Editor,.We greatly enjoyed reading the excellent review article by Alavian, et al., (1) on the epidemiology of hepatitis B virus (HBV) infection in Iranian general population. Reviewing over 250 related articles in this paper as well as inclusion of non-published reports from libraries of different universities of all parts of the country, has made the paper so perfect that one may find any data derived from different studies on the epidemiology of HBV infection in Iran within this artic...

  14. Occult hepatitis B virus infection and blood transfusion

    OpenAIRE

    Seo, Dong Hee; Whang, Dong Hee; Song, Eun Young; Han, Kyou Sup

    2015-01-01

    Transfusion-transmitted infections including hepatitis B virus (HBV) have been a major concern in transfusion medicine. Implementation of HBV nucleic acid testing (NAT) has revealed occult HBV infection (OBI) in blood donors. In the mid-1980s, hepatitis B core antibody (HBc) testing was introduced to screen blood donors in HBV non-endemic countries to prevent transmission of non-A and non-B hepatitis. That test remains in use for preventing of potential transmission of HBV from hepatitis B su...

  15. Neuromyelitis optica in patients with coexisting human immunodeficiency virus infections.

    Science.gov (United States)

    Feyissa, Anteneh M; Singh, Parbhdeep; Smith, Robert G

    2013-09-01

    Two patients with known human immunodeficiency virus (HIV) infections and receiving antiretroviral treatment developed neuromyelitis optica (Devic's disease). One patient tested positive for serum aquaporin-4 immunoglobulin G antibodies. Both patients were treated with high dose pulsed intravenous methylprednisolone followed by standard sessions of plasma exchange both at the onset attack and during disease relapses. For maintenance therapy, one patient received rituximab infusions and the second patient received mycophenolate mofetil orally. Despite treatment, both patients are currently wheelchair-bound due to severe paraparesis. Neuromyelitis optica can occur in the course of HIV infection and poses an ongoing therapeutic challenge.

  16. Detection of Zika Virus Infection in Thailand, 2012-2014.

    Science.gov (United States)

    Buathong, Rome; Hermann, Laura; Thaisomboonsuk, Butsaya; Rutvisuttinunt, Wiriya; Klungthong, Chonticha; Chinnawirotpisan, Piyawan; Manasatienkij, Wudtichai; Nisalak, Ananda; Fernandez, Stefan; Yoon, In-Kyu; Akrasewi, Passakorn; Plipat, Tanarak

    2015-08-01

    Zika virus (ZIKV) is an emerging mosquito-borne pathogen with reported cases in Africa, Asia, and large outbreaks in the Pacific. No autochthonous ZIKV infections have been confirmed in Thailand. However, there have been several cases reported in travelers returning from Thailand. Here we report seven cases of acute ZIKV infection in Thai residents across the country confirmed by molecular or serological testing including sequence data. These endemic cases, combined with previous reports in travelers, provide evidence that ZIKV is widespread throughout Thailand.

  17. Caesarean Section and Hospitalization for Respiratory Syncytial Virus Infection

    DEFF Research Database (Denmark)

    Kristensen, Kim; Fisker, Niels; Haerskjold, Ann;

    2015-01-01

    BACKGROUND AND OBJECTIVE:: Hospitalization for respiratory syncytial virus (RSV) infection and asthma share common determinants, and meta-analyses indicate that children delivered by caesarean section (CS) are at increased risk of asthma. We aimed to investigate whether birth by CS is associated...... regression with adjustment for prematurity, asphyxia, birth weight, multiple births, single parenthood, maternal smoking during pregnancy, older siblings, and asthma diagnoses up to 2 weeks before hospitalization for RSV infection, to compare the effects of acute or elective CS versus vaginal delivery...

  18. Influenza and respiratory syncytial virus infections in British Hajj pilgrims

    Directory of Open Access Journals (Sweden)

    R Booy

    2008-01-01

    Full Text Available Viral respiratory infections including influenza and respiratory syncytial virus (RSV have been reported during the Hajj among international pilgrims. To help establish the burden of these infections at the Hajj, we set up a study to confirm these diagnoses in symptomatic British pilgrims who attended the 2005 Hajj. UK pilgrims with symptoms of upper respiratory tract infection (URTI were invited to participate; after taking medical history, nasal swabs were collected for point-of-care testing (PoCT of influenza and for subsequent PCR analysis for influenza and RSV. Of the 205 patients recruited, 37 (18% were positive for either influenza or RSV. Influenza A (H3 accounted for 54% (20/37 of the virus-positive samples, followed by RSV 24% (9/37, influenza B 19% (7/37, and influenza A (H1 3% (1/37. Of the influenza-positive cases, 29% (8/28 had recently had a flu immunisation. Influenza was more common in those who gave a history of contact with a pilgrim with a respiratory illness than those who did not (17 versus 9%. The overall rate of RSV was 4% (9/202. This study confirms that influenza and RSV cause acute respiratory infections in British Hajj pilgrims. Continuing surveillance and a programme of interventions to contain the spread of infection are needed at the Hajj, particularly when the world is preparing for an influenza pandemic.

  19. Hepatitis A virus infection: Epidemiology and genetic diversity

    Directory of Open Access Journals (Sweden)

    Báez Triana, Paula Andrea

    2015-04-01

    Full Text Available Hepatitis A virus infection is a global public health problem. The virus has a wide range of distribution and it is the main cause of acute hepatitis transmitted by the enteric route in Latin America. The viral particle is stable under environmental conditions and conserves its infectivity for several weeks, enabling its transmission by contaminated water and food. Worldwide, different epidemiological patterns have been identified, which may change over time by modification of social and economic variables in the population such as vaccination and the improvement of hygiene and primary health conditions. This leaves new populations susceptible to infection. In Latin America the circulation of genotype I and subgenotypes A and B has been described, but more research is needed to provide the knowledge needed to manage the prevention and control plans for the worldwide reduction of the prevalence of infection. For this paper, a literature review was performed on the SciELO, PubMed and ScienceDirect databases under the search terms "Hepatitis A", "Epidemiology," "Seroprevalence" and "Infection." From the results obtained, only papers published in English and Spanish to describe epidemiological and molecular studies of interest in Latin America were included.

  20. Gamma interferon augments Fc gamma receptor-mediated dengue virus infection of human monocytic cells.

    OpenAIRE

    Kontny, U; Kurane, I; Ennis, F A

    1988-01-01

    It has been reported that anti-dengue antibodies at subneutralizing concentrations augment dengue virus infection of monocytic cells. This is due to the increased uptake of dengue virus in the form of virus-antibody complexes by cells via Fc gamma receptors. We analyzed the effects of recombinant human gamma interferon (rIFN-gamma) on dengue virus infection of human monocytic cells. U937 cells, a human monocytic cell line, were infected with dengue virus in the form of virus-antibody complexe...

  1. Predicted pattern of Zika virus infection distribution with reference to rainfall in Thailand.

    Science.gov (United States)

    Wiwanitkit, Somsri; Wiwanitkit, Viroj

    2016-07-01

    Zika virus infection is the present global medical problem. The disease appears in several countries around the world. The relationship between rainfall and occurrence of Zika virus infection was previously mentioned. Here, the authors use the mathematical modeling technique to reappraise on the previous data on immunoreactivity rate of Zika virus, dengue virus and Ckikungunya virus in Thailand and the reported interrelationship between arboviral infections and rainfall in Thailand for constructing of the predicted pattern of Zika virus distribution in Thailand. This data can be a useful tool for further disease surveillance in this area.

  2. Predicted pattern of Zika virus infection distribution with reference to rainfall in Thailand.

    Science.gov (United States)

    Wiwanitkit, Somsri; Wiwanitkit, Viroj

    2016-07-01

    Zika virus infection is the present global medical problem. The disease appears in several countries around the world. The relationship between rainfall and occurrence of Zika virus infection was previously mentioned. Here, the authors use the mathematical modeling technique to reappraise on the previous data on immunoreactivity rate of Zika virus, dengue virus and Ckikungunya virus in Thailand and the reported interrelationship between arboviral infections and rainfall in Thailand for constructing of the predicted pattern of Zika virus distribution in Thailand. This data can be a useful tool for further disease surveillance in this area. PMID:27393105

  3. RESPIRATORY SYNCYTIAL VIRUS INFECTION AMONG YOUNG CHILDREN WITH ACUTE RESPIRATORY INFECTION

    OpenAIRE

    Milani, M

    2003-01-01

    Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infections in infants,and also an important factor for hospitalization during the winter months. To determine the prevalence and importance of RSV as a cause of acute lower respiratory tract infection, we carried out a prospective study during 5 months period from November to March 1998 in 6 pediatric hospitals. A nasopharyngeal aspirate was obtained for detection of RSV in all cases. Sociodemographic data, clinic...

  4. Varicella zoster virus infection causing urinary retention in a child with HIV infection

    OpenAIRE

    G S Wessels; C. F. Heyns

    2012-01-01

    An 11-year-old boy receiving antiretroviral therapy for HIV infection and antibacterial therapy for pulmonary tuberculosis presented with urinary retention due to varicella zoster virus infection involving the sacral nerves, confirmed on serological testing. The perineum over dermatomes S2 - S4 on the left was involved with a vesicular and superficially erosive rash. A transurethral catheter was inserted and the patient was treated with acyclovir (300 mg 6-hourly for 5 days). At follow-up 4 w...

  5. Regional Aggressive Root Resorption Caused by Neuronal Virus Infection

    Directory of Open Access Journals (Sweden)

    Inger Kjær

    2012-01-01

    Full Text Available During orthodontic treatment, root resorption can occur unexplainably. No clear distinction has been made between resorption located within specific regions and resorption occurring generally in the dentition. The purpose is to present cases with idiopathic (of unknown origin root resorption occurring regionally. Two cases of female patients, 26 and 28 years old, referred with aggressive root resorption were investigated clinically and radiographically. Anamnestic information revealed severe virus diseases during childhood, meningitis in one case and whooping cough in the other. One of the patients was treated with dental implants. Virus spreading along nerve paths is a possible explanation for the unexpected resorptions. In both cases, the resorptions began cervically. The extent of the resorption processes in the dentition followed the virus infected nerve paths and the resorption process stopped when reaching regions that were innervated differently and not infected by virus. In one case, histological examination revealed multinuclear dentinoclasts. The pattern of resorption in the two cases indicates that innervation is a factor, which under normal conditions may protect the root surface against resorption. Therefore, the normal nerve pattern is important for diagnostics and for predicting the course of severe unexpected root resorption.

  6. Experimental infection of house sparrows (Passer domesticus) with Rocio virus.

    Science.gov (United States)

    Monath, T P; Kemp, G E; Cropp, C B; Bowen, G S

    1978-11-01

    Rocio encephalitis is a new epidemic flaviviral infection of man, first described in São Paulo State, Brazil in 1975. The ecology of the viral transmission cycle remains largely unknown. Experimental studies were undertaken to assess the role of a wild avian species, the House Sparrow, as a maintenance or amplifying host. Approximately two-thirds of nesting and adult sparrows developed 2- to 3-day viremias of low to moderate magnitude (2.0--4.3 log/ml). Rocio-immune birds were not protected against challenge with St. Louis encephalitis (SLE) virus, but prior SLE viral infection prevented detectable viremia in birds challenged with Rocio virus. These studies provide some support for the hypothesis that birds are hosts for Rocio virus, but the House Sparrow probably plays a relatively minor role in viral transmission. Because sparrows are relatively inefficient viremic hosts, they would be expected to play a minor role in transmission should Rocio virus be introduced into the United States.

  7. Neurological Complications of Ebola Virus Infection.

    Science.gov (United States)

    Billioux, Bridgette Jeanne; Smith, Bryan; Nath, Avindra

    2016-07-01

    Ebola virus disease is one of the deadliest pathogens known to man, with a mortality rate between 25-90% depending on the species and outbreak of Ebola. Typically, it presents with fever, headache, voluminous vomiting and diarrhea, and can progress to a hemorrhagic illness; neurologic symptoms, including meningoencephalitis, seizures, and coma, can also occur. Recently, an outbreak occurred in West Africa, affecting > 28,000 people, and killing > 11,000. Owing to the magnitude of this outbreak, and the large number (>17,000) of Ebola survivors, the medical and scientific communities are learning much more about the acute manifestations and sequelae of Ebola. A number of neurologic complications can occur after Ebola, such as seizures, memory loss, headaches, cranial nerve abnormalities, and tremor. Ebola may also persist in some immunologically privileged sites, including the central nervous system, and can rarely lead to relapse in disease. Owing to these findings, it is important that survivors are evaluated and monitored for neurologic symptoms. Much is unknown about this disease, and treatment remains largely supportive; however, with ongoing clinical and basic science, the mechanisms of how Ebola affects the central nervous system and how it persists after acute disease will hopefully become more clear, and better treatments and clinical practices for Ebola patients will be developed. PMID:27412684

  8. Infection of Avian Pox Virus in Oriental Turtle-Doves

    OpenAIRE

    Kyung-Yeon Eo1, Young-Hoan Kim2, Kwang-Hyun Cho3, Jong-Sik Jang4, Tae-Hwan Kim5, Dongmi Kwak5 and Oh-Deog Kwon5*

    2011-01-01

    Three Oriental Turtle-doves (Streptopelia orientalis) exhibiting lethargy, dyspnea, poor physical condition, and poor flight endurance, were rescued and referred to the Animal Health Center, Seoul Zoo, Korea. The doves had wart-like lesions on the legs and head. All of them died the following day after arrival, with the exception of one that survived for 6 days. Diphtheritic membranes on the tongue and oral mucosa were apparent at necropsy. Avian pox virus infection was suspected based on the...

  9. Neurocysticercosis and human immunodeficiency virus infection: a case report.

    Science.gov (United States)

    Chianura, Leonardo; Sberna, Maurizio; Moioli, Cristina; Villa, Maria Riccarda; Orcese, Carloandrea; Causarano, Renzo

    2006-01-01

    Ecuador is considered a holoendemic high-risk area for the transmission of cysticercosis. Moreover, the progression of human immunodeficiency virus (HIV) occurs worldwide. We present a case of simultaneous diagnosis of cysticercosis and HIV infection in a 22-year-old Ecuadorian immigrant. We would postulate that with the increasing HIV incidence in endemic areas of cysticercosis, the simultaneous diagnosis of both diseases is an event to be expected. PMID:17107432

  10. Association between Celiac Disease and Chronic Hepatitis C Virus Infection

    OpenAIRE

    Garg, Ashish; Reddy, Chandrasekhar; Duseja, Ajay; Chawla, Yogesh; Radha K. Dhiman

    2011-01-01

    Celiac disease affects the proximal small intestine and is caused by a local immune response to dietary gluten. Celiac disease usually presents with chronic diarrhea; however, presentations with elevated hepatic transaminase levels in blood or with iron-deficiency anemia have been described. Celiac disease has been reported to be associated with autoimmune liver diseases. Hepatitis C virus (HCV) can also initiate autoimmune disease process. Therefore, HCV infection and celiac disease may occu...

  11. Proteins synthesized in tobacco mosaic virus infected protoplasts

    International Nuclear Information System (INIS)

    The author deals with research on the multiplication of tobacco mosaic virus (TMV) in leaf cell protoplasts. An attempt is made to answer three questions: (1) Which proteins are synthesized in TMV infected protoplasts as a result of TMV multiplication. (2) Which of the synthesized proteins are made under the direction of the TMV genome and, if any, which of the proteins are host specific. (3) In which functions are these proteins involved. (Auth.)

  12. Chemical composition on cacao leaves infected by viruses

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa, M.; Delilah, M.; Syafrul, L.; Suryadi

    1980-09-01

    Chemical analysis on cacao leaves that have chlorosis spots caused by cacao swollen shoot viruses were carried out. It can be shown that leaves with chlorosis spots contain less chlorophyl and lipides than those without, but both do not show any significant difference in the concentration of water, glucose, saccharides, amino acid and proteins. It can be concluded that transport systems in the infected leaves are good so that the water and saccharides distribution in them are not disturbed.

  13. Cross-species infection of Deformed Wing virus poses a new threat to pollinator conservation

    Science.gov (United States)

    Here we provide the evidence that Deformed Wing Virus (DWV), one of the most prevalent and common viruses in honey bees Apis mellifera, could cause an infection in bumble bees, Bombus huntii and that the virus infection could spread over the entire body of B. huntii. Our results showed that gut of...

  14. Drug repurposing of minocycline against dengue virus infection.

    Science.gov (United States)

    Leela, Shilpa Lekshmi; Srisawat, Chatchawan; Sreekanth, Gopinathan Pillai; Noisakran, Sansanee; Yenchitsomanus, Pa-Thai; Limjindaporn, Thawornchai

    2016-09-01

    Dengue virus infection is one of the most common arthropod-borne viral diseases. A complex interplay between host and viral factors contributes to the severity of infection. The antiviral effects of three antibiotics, lomefloxacin, netilmicin, and minocycline, were examined in this study, and minocycline was found to be a promising drug. This antiviral effect was confirmed in all four serotypes of the virus. The effects of minocycline at various stages of the viral life cycle, such as during viral RNA synthesis, intracellular envelope protein expression, and the production of infectious virions, were examined and found to be significantly reduced by minocycline treatment. Minocycline also modulated host factors, including the phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2). The transcription of antiviral genes, including 2'-5'-oligoadenylate synthetase 1 (OAS1), 2'-5'-oligoadenylate synthetase 3 (OAS3), and interferon α (IFNA), was upregulated by minocycline treatment. Therefore, the antiviral activity of minocycline may have a potential clinical use against Dengue virus infection. PMID:27396621

  15. A dual drug regimen synergistically blocks human parainfluenza virus infection

    Science.gov (United States)

    Bailly, Benjamin; Dirr, Larissa; El-Deeb, Ibrahim M.; Altmeyer, Ralf; Guillon, Patrice; von Itzstein, Mark

    2016-04-01

    Human parainfluenza type-3 virus (hPIV-3) is one of the principal aetiological agents of acute respiratory illness in infants worldwide and also shows high disease severity in the elderly and immunocompromised, but neither therapies nor vaccines are available to treat or prevent infection, respectively. Using a multidisciplinary approach we report herein that the approved drug suramin acts as a non-competitive in vitro inhibitor of the hPIV-3 haemagglutinin-neuraminidase (HN). Furthermore, the drug inhibits viral replication in mammalian epithelial cells with an IC50 of 30 μM, when applied post-adsorption. Significantly, we show in cell-based drug-combination studies using virus infection blockade assays, that suramin acts synergistically with the anti-influenza virus drug zanamivir. Our data suggests that lower concentrations of both drugs can be used to yield high levels of inhibition. Finally, using NMR spectroscopy and in silico docking simulations we confirmed that suramin binds HN simultaneously with zanamivir. This binding event occurs most likely in the vicinity of the protein primary binding site, resulting in an enhancement of the inhibitory potential of the N-acetylneuraminic acid-based inhibitor. This study offers a potentially exciting avenue for the treatment of parainfluenza infection by a combinatorial repurposing approach of well-established approved drugs.

  16. Fatal canine distemper virus infection of giant pandas in China.

    Science.gov (United States)

    Feng, Na; Yu, Yicong; Wang, Tiecheng; Wilker, Peter; Wang, Jianzhong; Li, Yuanguo; Sun, Zhe; Gao, Yuwei; Xia, Xianzhu

    2016-01-01

    We report an outbreak of canine distemper virus (CDV) infection among endangered giant pandas (Ailuropoda melanoleuca). Five of six CDV infected giant pandas died. The surviving giant panda was previously vaccinated against CDV. Genomic sequencing of CDV isolated from one of the infected pandas (giant panda/SX/2014) suggests it belongs to the Asia-1 cluster. The hemagglutinin protein of the isolated virus and virus sequenced from lung samples originating from deceased giant pandas all possessed the substitutions V26M, T213A, K281R, S300N, P340Q, and Y549H. The presence of the Y549H substitution is notable as it is found at the signaling lymphocytic activation molecule (SLAM) receptor-binding site and has been implicated in the emergence of highly pathogenic CDV and host switching. These findings demonstrate that giant pandas are susceptible to CDV and suggest that surveillance and vaccination among all captive giant pandas are warranted to support conservation efforts for this endangered species. PMID:27310722

  17. A dual drug regimen synergistically blocks human parainfluenza virus infection.

    Science.gov (United States)

    Bailly, Benjamin; Dirr, Larissa; El-Deeb, Ibrahim M; Altmeyer, Ralf; Guillon, Patrice; von Itzstein, Mark

    2016-01-01

    Human parainfluenza type-3 virus (hPIV-3) is one of the principal aetiological agents of acute respiratory illness in infants worldwide and also shows high disease severity in the elderly and immunocompromised, but neither therapies nor vaccines are available to treat or prevent infection, respectively. Using a multidisciplinary approach we report herein that the approved drug suramin acts as a non-competitive in vitro inhibitor of the hPIV-3 haemagglutinin-neuraminidase (HN). Furthermore, the drug inhibits viral replication in mammalian epithelial cells with an IC50 of 30 μM, when applied post-adsorption. Significantly, we show in cell-based drug-combination studies using virus infection blockade assays, that suramin acts synergistically with the anti-influenza virus drug zanamivir. Our data suggests that lower concentrations of both drugs can be used to yield high levels of inhibition. Finally, using NMR spectroscopy and in silico docking simulations we confirmed that suramin binds HN simultaneously with zanamivir. This binding event occurs most likely in the vicinity of the protein primary binding site, resulting in an enhancement of the inhibitory potential of the N-acetylneuraminic acid-based inhibitor. This study offers a potentially exciting avenue for the treatment of parainfluenza infection by a combinatorial repurposing approach of well-established approved drugs. PMID:27053240

  18. Hepatitis C virus (HCV) and human immunodeficiency virus type 1 (HIV-1) infections in alcoholics.

    Science.gov (United States)

    Prakash, Om; Mason, Andrew; Luftig, Ronald B; Bautista, Abraham P

    2002-07-01

    Approximately 400,000 individuals in the United States are co-infected with hepatitis C virus (HCV) and human immunodeficiency virus type 1 (HIV-1) and it is likely that almost one in two of these subjects consumes alcohol. The majority of these patients suffer an accelerated course of liver disease as manifested by the onset of cirrhosis within 5 to 10 years of developing HCV infection, as well as an increased risk of developing hepatocellular carcinoma (HCC). It is thought that chronic alcohol abuse mediates liver damage as a result of increased production of free radicals and proinflammatory cytokines. In the setting of chronic HCV infection, alcohol ingestion has an additional effect of diminishing immune clearance and increasing viral burden to hasten the onset of cirrhosis and HCC. Likewise, chronic HCV and HIV-1 co-infection results in a net increase in HCV burden; higher prevalence rates of HCV transmission to sexual partners and offspring, as well as an accelerated progression to end stage liver disease as compared to individuals with HCV infection alone. Thus, the synergistic effects of alcohol abuse and HIV-1 greatly impact on the morbidity and mortality for patients with HCV coinfection. Ultimately, this cumulative disease process will require far more aggressive management with abstinence and counseling for alcohol abuse; highly active antiretroviral therapy (HAART) for HIV infection and combination anti-viral therapy for HCV infection to stem the rapid progression to end stage liver disease. PMID:12086918

  19. Serodiagnosis of Helicobacter pylori infection in patients with human immunodeficiency virus infection

    DEFF Research Database (Denmark)

    Nielsen, H; Andersen, L P

    1995-01-01

    In contrast to the established role of Helicobacter pylori gastritis in gastritis and duodenal ulcer in general, conflicting results have been reported in patients with human immunodeficiency virus (HIV) infection and the acquired immunodeficiency syndrome. The seroprevalence during early HIV...... infection is unknown. We retrospectively studied 102 patients with HIV infection early during the infection and in most cases in asymptomatic patients. Serological IgG antibody response to H. pylori was assessed by ELISA. Compared with an age-matched control group the seroprevalence of H. pylori positivity......) and 2 patients had H. pylori seroconverted, indicating an incidence of new infection of 2%/year. In conclusion, previous reports have underestimated the prevalence of H. pylori infection in HIV patients, which seems to be similar to that in an HIV-negative population....

  20. Pesti Des Petits ruminants virus infection in animals

    Directory of Open Access Journals (Sweden)

    Chauhan H.C.

    2009-08-01

    Full Text Available For centuries morbillivirus infections have had a huge impact on both human beings and animals. Morbilliviruses are highly contagious pathogens that cause some of the most devastating viral diseases of humans and animals world wide. They include measles virus (MV, canine distemper virus (CDV, rinderpest virus (RPV and peste des petits ruminants (PPRV virus. Furthermore, new emerging infectious diseases of morbilliviruses with significant ecological consequences of marine mammals have been discovered in the past decades. Phocid distemper virus (PDV in seals and the cetacean morbillivirus (CMV have been found in dolphins, whales and porpoises. Peste des petits ruminants (PPR is a highly contagious ,infectious , an acute or sub acute viral disease of domestic and wild small ruminants characterized by fever, oculonasal discharges, stomatitis, conjunctivitis, gastroenteritis and pneumonia. Goats are more severely affected than sheep. It is also known as pseudorinderpest of small ruminants, pest of small ruminants, pest of sheep and goats, kata, stomatitis- pneumoentritis syndrome, contagious pustular stomatitis and pneumoentritis complex. It is one of the major notifiable diseases of the World Organization for Animal Health (OIE. [Vet. World 2009; 2(4.000: 150-155

  1. Prior infection of pigs with swine influenza viruses is a barrier to infection with avian influenza viruses.

    Science.gov (United States)

    De Vleeschauwer, Annebel; Van Reeth, Kristien

    2010-12-15

    Although pigs are susceptible to avian influenza viruses (AIV) of different subtypes, the incidence of AIV infections in the field appears to be low. Swine H1N1, H3N2 and H1N2 influenza viruses (SIV) are enzootic worldwide and most pigs have antibodies to 1 or more SIV subtypes. This study aimed to examine whether infection-immunity to H1N1 or H3N2 SIV may (1) protect pigs against subsequent infections with AIV of various haemagglutinin and/or neuraminidase subtypes and/or (2) interfere with the serological diagnosis of AIV infection by haemagglutination inhibition (HI) or virus neutralization (VN) tests. Pigs were inoculated intranasally with an H1N1 or H3N2 SIV or left uninoculated. Four or 6 weeks later all pigs were challenged intranasally with 1 of 3 AIV subtypes (H4N6, H5N2 or H7N1). Fifteen out of 17 challenge control pigs shed the respective AIV for 4-6 days post-inoculation and 16 developed HI and VN antibodies. In contrast, 28 of the 29 SIV-immune pigs did not have detectable AIV shedding. Only 12 SIV-immune pigs developed HI antibodies to the AIV used for challenge and 14 had VN antibodies. Antibody titres to the AIV were low in both control and SIV-immune pigs. Our data show that prior infection of pigs with SIV is a barrier to infection with AIV of unrelated subtypes. Serological screening in regions where SIV is enzootic is only useful when the AIV strain for which the pigs need to be tested is known.

  2. Hepatitis B Virus Infection and Immunizations among Asian American College Students: Infection, Exposure, and Immunity Rates

    Science.gov (United States)

    Lee, Haeok; Kiang, Peter; Watanabe, Paul; Halon, Patricia; Shi, Ling; Church, Daniel R.

    2013-01-01

    Objectives: To evaluate the prevalence of hepatitis B virus (HBV) infection, exposure, and immunity among Asian American college students as a basis for evaluating HBV screening and vaccination policy. Participants and Methods: Self-identified Asian American college students aged 18 years or older were examined. Serological tests of HBV surface…

  3. Human Immunodeficiency Virus Type 1 Infection of Neural Xenografts

    Science.gov (United States)

    Cvetkovich, Therese A.; Lazar, Eliot; Blumberg, Benjamin M.; Saito, Yoshihiro; Eskin, Thomas A.; Reichman, Richard; Baram, David A.; del Cerro, Coca; Gendelman, Howard E.; del Cerro, Manuel; Epstein, Leon G.

    1992-06-01

    Human immunodeficiency virus type 1 (HIV-1) infection is highly specific for its human host. To study HIV-1 infection of the human nervous system, we have established a small animal model in which second-trimester (11 to 17.5 weeks) human fetal brain or neural retina is transplanted to the anterior chamber of the eye of immunosuppressed adult rats. The human xenografts vascularized, formed a blood-brain barrier, and differentiated, forming neurons and glia. The xenografts were infected with cell-free HIV-1 or with HIV-1-infected human monocytes. Analysis by polymerase chain reaction revealed HIV-1 sequences in DNA from xenograft tissue exposed to HIV-1 virions, and in situ hybridization demonstrated HIV-1 mRNA localized in macrophages and multinucleated giant cells. Pathological damage was observed only in neural xenografts containing HIV-1-infected human monocytes, supporting the hypothesis that these cells mediate neurotoxicity. This small animal model allows the study of direct and indirect effects of HIV-1 infection on developing human fetal neural tissues, and it should prove useful in evaluating antiviral therapies, which must ultimately target HIV-1 infection of the brain.

  4. Immunoprophylaxis of hepatitis B virus infection

    Directory of Open Access Journals (Sweden)

    Joshi N

    2001-01-01

    Full Text Available Hepatitis-B infection is a global health problem. The spectrum of the disease is highly variable ranging from mild disease to chronic liver diseases including hepatocellular carcinoma. There are approximately 350 million chronic Hepatitis-B surface antigen (HBsAg carriers in the world. Till date there is no effective therapy against this disease. Hence, prevention of the disease through vaccination is the only means to control the disease. Passive immunization is recommended for certain accidental exposures. Hepatitis-B immunoglobulin (HBIG contains high titers of anti-HBs prepared from pooled plasma. HBIG has been shown to be highly effective in preventing post exposure transmission. HBIG induces immunity for a short period only hence, it is recommended to have a course of active immunization following passive immunization. Active immunization is achieved using vaccination. Two generations of vaccines, 1st generation plasma derived and 2nd generation recombinant DNA vaccines are available. Both these vaccines have been used extensively in all age groups all over the world. The studies have shown that HB vaccines are clinically well tolerated, safe and highly immunogenic. Normally 3 doses of HB vaccines are recommended in 0, 1, 2 and 12 or 0, 1, 6 months schedule. The dosages and schedules may vary in certain special groups, such as infants and neonates, chronic renal failure patients on hemodialysis. Advisory committee on immunization practices (ACIP has given several guidelines regarding HB vaccination. Universal immunization of all infants and integration of HB Vaccine in the expanded program of immunization has been recommended by World Health Organization. Universal infant immunization is cost effective. Universal immunization of infants is the only strategy that will lead to the control and eradication of HBV infection in all regions of the world. Several countries have adopted this policy. But in India we have several problems in

  5. Autonomic nervous dysfunction in hamsters infected with West Nile virus.

    Directory of Open Access Journals (Sweden)

    Hong Wang

    Full Text Available Clinical studies and case reports clearly document that West Nile virus (WNV can cause respiratory and gastrointestinal (GI complications. Other functions controlled by the autonomic nervous system may also be directly affected by WNV, such as bladder and cardiac functions. To investigate how WNV can cause autonomic dysfunctions, we focused on the cardiac and GI dysfunctions of rodents infected with WNV. Infected hamsters had distension of the stomach and intestines at day 9 after viral challenge. GI motility was detected by a dye retention assay; phenol red dye was retained more in the stomachs of infected hamsters as compared to sham-infected hamsters. The amplitudes of electromygraphs (EMGs of intestinal muscles were significantly reduced. Myenteric neurons that innervate the intestines, in addition to neurons in the brain stem, were identified to be infected with WNV. These data suggest that infected neurons controlling autonomic function were the cause of GI dysfunction in WNV-infected hamsters. Using radiotelemetry to record electrocardiograms and to measure heart rate variability (HRV, a well-accepted readout for autonomic function, we determined that HRV and autonomic function were suppressed in WNV-infected hamsters. Cardiac histopathology was observed at day 9 only in the right atrium, which was coincident with WNV staining. A subset of WNV infected cells was identified among cells with hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4 as a marker for cells in the sinoatrial (SA and atrioventricular (AV nodes. The unique contribution of this study is the discovery that WNV infection of hamsters can lead to autonomic dysfunction as determined by reduced HRV and reduced EMG amplitudes of the GI tract. These data may model autonomic dysfunction of the human West Nile neurological disease.

  6. Effects of chloroquine and cytochalasin B on the infection of cells by Sindbis virus and vesicular stomatitis virus.

    OpenAIRE

    Coombs, K; Mann, E; Edwards, J; Brown, D T

    1981-01-01

    The effects of cytochalasin B and chloroquine on the process of endocytosis of Sindbis virus particles and polystyrene spheres were determined by electron microscopy. The effects of these agents on the process of infection (attachment, penetration, and uncoating) of BHK-21 cells by Sindbis virus and vesicular stomatitis virus were also determined. Cytochalasin B completely blocked ingestion of Sindbis virus particles or latex spheres by BHK cells but had no effect on the ability of Sindbis vi...

  7. No Evidence for Infection of UK Prostate Cancer Patients with XMRV, BK Virus, Trichomonas vaginalis or Human Papilloma Viruses

    OpenAIRE

    Groom, Harriet C. T.; Warren, Anne Y; David E Neal; Kate N Bishop

    2012-01-01

    The prevalence of specific infections in UK prostate cancer patients was investigated. Serum from 84 patients and 62 controls was tested for neutralisation of xenotropic murine leukaemia virus-related virus (XMRV) Envelope. No reactivity was found in the patient samples. In addition, a further 100 prostate DNA samples were tested for XMRV, BK virus, Trichomonas vaginalis and human papilloma viruses by nucleic acid detection techniques. Despite demonstrating DNA integrity and assay sensitivity...

  8. Hepatitis C virus infections among HIV-infected men who have sex with men: an expanding epidemic

    NARCIS (Netherlands)

    A.T. Urbanus; T.J. van de Laar; I.G. Stolte; J. Schinkel; T. Heijman; R.A. Coutinho; M. Prins

    2009-01-01

    Background: Since 2000 outbreaks of sexually transmitted hepatitis C Virus (HCV) infections have been reported among HIV-infected men who have sex with men (MSM). We studied the prevalence and determinants of HCV-infection among MSM attending a large sexually transmitted infection (STI) clinic in th

  9. Detection of Lassa virus RNA in specimens from patients with Lassa fever by using the polymerase chain reaction.

    Science.gov (United States)

    Lunkenheimer, K; Hufert, F T; Schmitz, H

    1990-01-01

    Suitable oligonucleotide primers and probes were synthesized to amplify Lassa virus (Josiah strain)-specific nucleoprotein and glycoprotein gene fragments by using reverse transcription combined with the polymerase chain reaction (PCR). Our primers did not amplify the related lymphocytic choriomeningitis virus. By using PCR, about 50 50% tissue culture infective doses could be detected in the supernatant of infected cells. Furthermore, in all five serum specimens and four of five urine specimens of patients with acute Lassa fever, viral RNA could be demonstrated. Negative results were obtained with all serum and urine specimens of healthy subjects. Our data suggest that PCR may be applied as an alternative to virus isolation in the rapid diagnosis of Lassa fever. Images PMID:2279999

  10. The Lassa fever virus L gene: nucleotide sequence, comparison, and precipitation of a predicted 250 kDa protein with monospecific antiserum

    Science.gov (United States)

    Lukashevich, Igor S.; Djavani, Mahmoud; Shapiro, Keli; Sanchez, Anthony; Ravkov, Eugene; Nichol, Stuart T.; Salvato, Maria S.

    2008-01-01

    The large (L) RNA segment of Lassa fever virus (LAS) encodes a putative RNA-dependent RNA polymerase (RdRp or L protein). Similar to other arenaviruses, the LAS L protein is encoded on the genome-complementary strand and is predicted to be 2218 amino acids in length (253 kDa). It has an unusually large non-coding region adjacent to its translation start site. The LAS L protein contains six motifs of conserved amino acids that have been found among arenavirus L proteins and core RdRp of other segmented negative-stranded (SNS) viruses (Arena-, Bunya- and Orthomyxoviridae). Phylogenetic analyses of the RdRp of 20 SNS viruses reveals that arenavirus L proteins represent a distinct cluster divided into LAS–lymphocytic choriomeningitis and Tacaribe–Pichinde virus lineages. Monospecific serum against a synthetic peptide corresponding to the most conserved central domain precipitates a 250 kDa product from LAS and lymphocytic choriomeningitis virus-infected cells. PMID:9049403

  11. Hepatitis C virus infection among transmission-prone medical personnel.

    Science.gov (United States)

    Zaaijer, H L; Appelman, P; Frijstein, G

    2012-07-01

    Hepatitis C virus (HCV)-infected physicians have been reported to infect some of their patients during exposure-prone procedures (EPPs). There is no European consensus on the policy for the prevention of this transmission. To help define an appropriate preventive policy, we determined the prevalence of HCV infection among EPP-performing medical personnel in the Academic Medical Center in Amsterdam, the Netherlands. The prevalence of HCV infection was studied among 729 EPP-performing health care workers. Serum samples, stored after post-hepatitis B virus (HBV) vaccination testing in the years 2000-2009, were tested for HCV antibodies. Repeat reactive samples were confirmed by immunoblot assay and the detection of HCV RNA. The average age of the 729 health care workers was 39 years (range 18-66), suggesting a considerable cumulative occupational exposure to the blood. Nevertheless, only one of the 729 workers (0.14%; 95% confidence interval [CI]: <0.01% to 0.85%) was tested and confirmed to be positive for anti-HCV and positive for HCV RNA, which is comparable to the prevalence of HCV among Amsterdam citizens. Against this background, for the protection of personnel and patients, careful follow-up after needlestick injuries may be sufficient. If a zero-risk approach is desirable and costs are less relevant, the recurrent screening of EPP-performing personnel for HCV is superior to the follow-up of reported occupational exposures.

  12. Host immune status and response to hepatitis E virus infection.

    Science.gov (United States)

    Krain, Lisa J; Nelson, Kenrad E; Labrique, Alain B

    2014-01-01

    Hepatitis E virus (HEV), identified over 30 years ago, remains a serious threat to life, health, and productivity in developing countries where access to clean water is limited. Recognition that HEV also circulates as a zoonotic and food-borne pathogen in developed countries is more recent. Even without treatment, most cases of HEV-related acute viral hepatitis (with or without jaundice) resolve within 1 to 2 months. However, HEV sometimes leads to acute liver failure, chronic infection, or extrahepatic symptoms. The mechanisms of pathogenesis appear to be substantially immune mediated. This review covers the epidemiology of HEV infection worldwide, the humoral and cellular immune responses to HEV, and the persistence and protection of antibodies produced in response to both natural infection and vaccines. We focus on the contributions of altered immune states (associated with pregnancy, human immunodeficiency virus [HIV], and immunosuppressive agents used in cancer and transplant medicine) to the elevated risks of chronic infection (in immunosuppressed/immunocompromised patients) and acute liver failure and mortality (among pregnant women). We conclude by discussing outstanding questions about the immune response to HEV and interactions with hormones and comorbid conditions. These questions take on heightened importance now that a vaccine is available.

  13. Phospholipid Synthesis in Sindbis Virus-Infected Cells

    Science.gov (United States)

    Waite, Marilynn R. F.; Pfefferkorn, E. R.

    1970-01-01

    We investigated the metabolic requirements for the decrease in phospholipid synthesis previously observed by Pfefferkorn and Hunter in primary cultures of chick embryo fibroblasts infected with Sindbis virus. The incorporation of 32PO4 into all classes of phospholipids was found to decline at the same rate and to the same extent; thus, incorporation of 14C-choline into acid-precipitable form provided a convenient measure of phospholipid synthesis that was used in subsequent experiments. Experiments with temperature-sensitive mutants suggested that some viral ribonucleic acid (RNA) synthesis was essential for the inhibition of choline incorporation, but that functional viral structural proteins were not required. The reduction in phospholipid synthesis was probably a secondary effect of infection resulting from viral inhibition of the cellular RNA and protein synthesis. All three inhibitory effects required about the same amount of viral RNA synthesis; the inhibition of host RNA and protein synthesis began sooner than the decline in phospholipid synthesis; and both actinomycin D and cycloheximide inhibited 14C-choline incorporation in uninfected cells. In contrast, incorporation of 14C-choline into BHK-21 cells was not decreased by 10 hr of exposure to actinomycin D and declined only slowly after cycloheximide treatment. Growth of Sindbis virus in BHK cells did not cause the marked stimulation of phospholipid synthesis seen in picornavirus infections of other mammalian cells; however, inhibition was seen only late in infection. PMID:5530011

  14. Diagnostic strategy for occult hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    Sara Ocana; Maria Luisa Casas; Ingrid Buhigas; Jose Luis Lledo

    2011-01-01

    In 2008, the European Association for the study of the liver (EASL) defined occult hepatitis B virus infection (OBI) as the "presence of hepatitis B virus (HBV) DNA in the liver (with detectable or undetectable HBV DNA in the serum) of individuals testing hepatitis B surface antigen (HBsAg) negative by currently available assays". Several aspects of occult HBV infection are still poorly understood, including the definition itself and a standardized approach for laboratory-based detection, which is the purpose of this review. The clinical significance of OBI has not yet been established; however, in terms of public health, the clinical importance arises from the risk of HBV transmission. Consequently, it is important to detect high-risk groups for occult HBV infection to prevent transmission. The main issue is, perhaps, to identify the target population for screening OBI. Viremia is very low or undetectable in occult HBV infection, even when the most sensitive methods are used, and the detection of the viral DNA reservoir in hepatocytes would provide the best evaluation of occult HBV prevalence in a defined set of patients. However, this diagnostic approach is obviously unsuitable: blood detection of occult hepatitis B requires assays of the highest sensitivity and specificity with a lower limit of detection < 10 IU/mL for HBV DNA and < 0.1 ng/mL for HBsAg.

  15. Cluster of Nipah virus infection, Kushtia District, Bangladesh, 2007.

    Directory of Open Access Journals (Sweden)

    Nusrat Homaira

    Full Text Available OBJECTIVE: In March 2007, we investigated a cluster of Nipah encephalitis to identify risk factors for Nipah infection in Bangladesh. METHODS: We defined confirmed Nipah cases by the presence of IgM and IgG antibodies against Nipah virus in serum. Case-patients, who resided in the same village during the outbreak period but died before serum could be collected, were classified as probable cases. RESULTS: We identified three confirmed and five probable Nipah cases. There was a single index case. Five of the secondary cases came in close physical contact to the index case when she was ill. Case-patients were more likely to have physical contact with the index case (71% cases versus 0% controls, p = <0.001. The index case, on her third day of illness, and all the subsequent cases attended the same religious gathering. For three probable cases including the index case, we could not identify any known risk factors for Nipah infection such as physical contact with Nipah case-patients, consumption of raw date palm juice, or contact with sick animals or fruit bats. CONCLUSION: Though person-to-person transmission remains an important mode of transmission for Nipah infection, we could not confirm the source of infection for three of the probable Nipah case-patients. Continued surveillance and outbreak investigations will help better understand the transmission of Nipah virus and develop preventive strategies.

  16. [BK virus infection in a pediatric renal transplant recipient].

    Science.gov (United States)

    Bonaventura, R; Vázquez, A; Exeni, A; Rivero, K; Freire, M C

    2005-01-01

    BK Human Polyomavirus causes an asymptomatic primary infection in children, then establishing latency mainly in the urinary tratt. Viral reactivation can lead to renal pathology in individuals with impaired cellular immune response. This is particularly important in pediatric transplant recipients, who can suffer a primary infection when immunosupressed. We followed up the case of a 5 years old patient who received a renal transplant in October 2003, and presented damaged graft 45 days after the intervention. The patient suffered 3 episodes of renal function failure between October 2003 and June 2004. Blood, urine, renal biopsy and lymphocele liquid samples were analyzed. A differential diagnosis between acute rejection and infectious causes was established by testing for BK, CMV and ADV viruses, and the cytological study of renal tissue. Laboratory findings together with clinical signs suggest the patient was infected by BK virus. As a final consideration, the great importance of differentiating between acute rejection and BK infection is emphasized, since immunosuppressant management is opposite in each case.

  17. Pathogenesis of occult chronic hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    Rocio Aller de la Fuente; María L Gutiérrez; Javier Garcia-Samaniego; Conrado Fernández-Rodriguez; Jose Luis Lledó; Gregorio Castellano

    2011-01-01

    Occult hepatitis B infection (OBI) is characterized by hepatitis B virus (HBV) DNA in serum in the absence of hepatitis B surface antigen (HBsAg) presenting HBsAg-negative and anti-HBc positive serological patterns. Occult HBV status is associated in some cases with mutant viruses undetectable by HBsAg assays; but more frequently it is due to a strong suppression of viral replication and gene expression. OBI is an entity with world-wide diffusion. The failure to detect HBsAg, despite the persistence of the viral DNA, is due in most cases to the strong suppression of viral replication and gene expression that characterizes this "occult" HBV infection; although the mechanisms responsible for suppression of HBV are not well understood. The majority of OBI cases are secondary to overt HBV infection and represent a residual low viremia level suppressed by a strong immune response together with histological derangements which occurred during acute or chronic HBV infection. Much evidence suggests that it can favour the progression of liver fibrosis and the development of hepatocellular carcinoma.

  18. Effects of lyophilization on the infectivity of enveloped and non-enveloped viruses in bone tissue.

    Science.gov (United States)

    Uhlenhaut, Christine; Dörner, Thomas; Pauli, Georg; Pruss, Axel

    2005-11-01

    Recently reported qualitative experiments proved that retroviral infectivity is not destroyed by lyophilization performed on systemically infected bone and tendon. The now accomplished quantitative determination of residual infectivity for enveloped and non-enveloped viruses allows a validation of the production process regarding viral safety in freeze-dried bone transplants. The lyophilization effect on the infectivity of two non-enveloped viruses (Maus Elberfeld virus, MEV; Porcine parvovirus, PPV) and one enveloped virus (Vesicular Stomatitis virus, VSV) was examined for virus-spiked bone material in comparison to lyophilized viruses, original virus stock, and air-dried viruses. All experiments were carried out with both cell-free and cell-associated virus. Significant differences were observed regarding the reduction of virus titers (TCID50). Infectivity of VSV was reduced by about 3-4 log10 using lyophilization in presence of bone matrix and of MEV by 6-7 log10, while no substantial reduction in virus titers was observed for PPV. Lyophilization of cell-free or cell-associated virus is not sufficient to inactivate viruses completely. However, lyophilization could have an additive effect in line with other production steps used in the manufacturing process.

  19. Hepatitis B virus/human immunodeficiency virus coinfection:interaction among human immunodeficiency virus infection,chronic hepatitis B virus infection, and host immunity

    Institute of Scientific and Technical Information of China (English)

    LI Yi-jia; WANG Huan-ling; LI Tai-sheng

    2012-01-01

    Objective This review discusses progress in the studies of hepatitis B virus (HBV)/human immunodeficiency virus (HIV) coinfection and focuses on the interaction among HIV infection,chronic HBV infection,and host immunity.Data sources Data and studies published mainly from 2008 to 2011 were selected using PubMed.Study selection Original articles and critical reviews concerning HBV/HIV coinfection and HBV and HIV pathogenesis were selected.Results HIV may accelerate HBV progression by lowering CD4 count,weakening HBV-specific immunity,“enriching”HBV mutants,causing immune activation,etc.On the other hand,HBV may enhance HIV replication by activating HIV long terminal repeat (LTR) with X protein (HBX) and cause immune activation in synergy with HIV.Paradoxically,HBV may also inhibit HIV dissemination via dendritic cells.Conclusions The interaction among HIV,HBV,and host immunity remains poorly understood.Further research is warranted to elucidate the detailed molecular mechanisms and to translate these mechanisms into clinical practice.

  20. Infection of Murine Macrophages by Salmonella enterica Serovar Heidelberg Blocks Murine Norovirus Infectivity and Virus-induced Apoptosis.

    Directory of Open Access Journals (Sweden)

    Sudhakar S Agnihothram

    Full Text Available Gastroenteritis caused by bacterial and viral pathogens constitutes a major public health threat in the United States accounting for 35% of hospitalizations. In particular, Salmonella enterica and noroviruses cause the majority of gastroenteritis infections, with emergence of sporadic outbreaks and incidence of increased infections. Although mechanisms underlying infections by these pathogens have been individually studied, little is known about the mechanisms regulating co-infection by these pathogens. In this study, we utilized RAW 264.7 murine macrophage cells to investigate the mechanisms governing co-infection with S. enterica serovar Heidelberg and murine norovirus (MNV. We demonstrate that infection of RAW 264.7 cells with S. enterica reduces the replication of MNV, in part by blocking virus entry early in the virus life cycle, and inducing antiviral cytokines later in the infection cycle. In particular, bacterial infection prior to, or during MNV infection affected virus entry, whereas MNV entry remained unaltered when the virus infection preceded bacterial invasion. This block in virus entry resulted in reduced virus replication, with the highest impact on replication observed during conditions of co-infection. In contrast, bacterial replication showed a threefold increase in MNV-infected cells, despite the presence of antibiotic in the medium. Most importantly, we present evidence that the infection of MNV-infected macrophages by S. enterica blocked MNV-induced apoptosis, despite allowing efficient virus replication. This apoptosis blockade was evidenced by reduction in DNA fragmentation and absence of poly-ADP ribose polymerase (PARP, caspase 3 and caspase 9 cleavage events. Our study suggests a novel mechanism of pathogenesis whereby initial co-infection with these pathogens could result in prolonged infection by either of these pathogens or both together.

  1. Risk Factors for Hospitalization for Respiratory Syncytial Virus Infection

    DEFF Research Database (Denmark)

    Haerskjold, Ann; Kristensen, Kim; Kamper-Jørgensen, Mads;

    2016-01-01

    of gestational age. Plurality was associated with a decreased risk in children born between 23 and 36 weeks of gestation, whereas young maternal age, maternal asthma, single parenthood, maternal smoking, being born small for gestational age, Caesarian section, male gender and day care were associated......BACKGROUND: The aim of this study is to identify the risk factors for hospitalization for respiratory syncytial virus (RSV) infection in Danish children. METHODS: This is a population-based cohort study with follow-up till 24 months of age. A total of 421,943 Danish children were divided into 5...... groups based on gestational age (23-32, 33-35, 36, 37-41 and 42-45 weeks). RESULTS: In adjusted Cox regression models, chronic disease, asthma hospitalization before the RSV infection and siblings were associated with an increased risk of hospitalization for RSV infection in all children independent...

  2. Cardiovascular implications from untreated human immunodeficiency virus infection

    DEFF Research Database (Denmark)

    Baker, Jason V; Lundgren, Jens D

    2011-01-01

    particle changes (e.g. high-density lipoprotein particles). Some of these mechanisms are attenuated, though incompletely, with antiretroviral therapy (ART)-related suppression of HIV replication. Exposure to ART is also associated with variable toxicity that may simultaneously decrease (via viral......Atherosclerotic cardiovascular disease (CVD) has become an important cause of morbidity and mortality among individuals with human immunodeficiency virus (HIV) infection with access to antiretroviral medications, as the risk for AIDS has fallen and life expectancy improved. Traditional CVD risk...... factors are often more common among individuals with HIV infection, and traditional prevention strategies remain important. Recent data have revealed that untreated HIV infection itself amplifies additional pro-atherogenic mechanisms related to immune activation, inflammation, coagulation, and lipoprotein...

  3. [Pulmonary complications in children with human immunodeficiency virus infection].

    Science.gov (United States)

    Brockmann V, Pablo; Viviani S, Támara; Peña D, Anamaría

    2007-08-01

    Pulmonary complications in children infected by human immunodeficiency virus (HIV) are common and may be the first manifestation of acquired immunodeficiency syndrome (AIDS). The aim of our study was to review pulmonary diseases and complications in pediatric patients with HIV infection in a large tertiary hospital in Santiago, Chile. We performed a retrospective, descriptive analysis of 17 patients with HIV infection controlled at the Hospital Dr. Sótero del Rio. Respiratory complications/diseases were: overall pneumonia (n: 14), recurrent pneumonia (n: 10), citomegalovirus associated pneumonia (n: 4), Pneumocystis jiroveci associated pneumonia (n: 1) pulmonary tuberculosis (n: 1), lymphoid interstitial pneumonia (n: 3) and chronic pulmonary disease (n: 7). Microorganisms isolated were mostly atypical and frequently associated with severe and chronic pulmonary damage. A high degree of suspicion is required to detect atypical microorganisms promptly, in order to rapidly implement pathogen targeted therapy that could potentially decrease the possibility of sequelae. PMID:17728918

  4. Autonomic evaluation of hepatitis C virus infected patients

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    Bruno Mattos Coutinho

    2013-08-01

    Full Text Available There are few studies reporting the association between hepatitis C virus (HCV infection and disautonomia. We have evaluated the autonomic cardiovascular function in 12 patients with sensory small-fiber polyneuropathy infected by HCV. The mean age was 49±13 years old. The mean infection time was 9.6 years in six (50% patients. Thermal and pinprick hypoesthesia was observed in distal legs in all patients. Autonomic symptoms were referred by eight (66.7% patients. Among patients with abnormal autonomic cardiovascular test, five (41.7% showed abnormal results in two or more tests. Valsalva maneuver was abnormal in seven (58.3% patients. We can consider that there is an association of both parasympathetic and sympathetic efferent cardiovascular dysfunction in this group of patients.

  5. Heterogeneous and Dynamic Prevalence of Asymptomatic Influenza Virus Infections

    Science.gov (United States)

    Furuya-Kanamori, Luis; Cox, Mitchell; Milinovich, Gabriel J.; Magalhaes, Ricardo J. Soares; Mackay, Ian M.

    2016-01-01

    Influenza infection manifests in a wide spectrum of severity, including symptomless pathogen carriers. We conducted a systematic review and meta-analysis of 55 studies to elucidate the proportional representation of these asymptomatic infected persons. We observed extensive heterogeneity among these studies. The prevalence of asymptomatic carriage (total absence of symptoms) ranged from 5.2% to 35.5% and subclinical cases (illness that did not meet the criteria for acute respiratory or influenza-like illness) from 25.4% to 61.8%. Statistical analysis showed that the heterogeneity could not be explained by the type of influenza, the laboratory tests used to detect the virus, the year of the study, or the location of the study. Projections of infection spread and strategies for disease control require that we identify the proportional representation of these insidious spreaders early on in the emergence of new influenza subtypes or strains and track how this rate evolves over time and space. PMID:27191967

  6. An overview of occult hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    Zeinab Nabil Ahmed Said

    2011-01-01

    Occult hepatitis B virus (HBV) infection (OBI), alternatively defined as occult hepatitis B (OHB), is a challenging clinical entity. It is recognized by two main characteristics: absence of HBsAg, and low viral replication. The previous two decades have witnessed a remarkable progress in our nderstanding of OBI and its clinical implications. Appropriate diagnostic techniques must be adopted. Sensitive HBV DNA amplification assay is the gold standard assay for detection of OBI. Viral as well as host factors are implicated in the pathogenesis of OBI. However, published data reporting the infectivity of OBI by transfusion are limited. Several aspects including OBI transmission, infectivity and its relation to the development of chronic liver diseases and hepatocellular carcinoma have to be resolved. The aim of the present review is to highlight recent data on OBI with a focus on its virological diagnosis and clinical outcome.

  7. Experimental Infections of Wild Birds with West Nile Virus

    Directory of Open Access Journals (Sweden)

    Elisa Pérez-Ramírez

    2014-02-01

    Full Text Available Avian models of West Nile virus (WNV disease have become pivotal in the study of infection pathogenesis and transmission, despite the intrinsic constraints that represents this type of experimental research that needs to be conducted in biosecurity level 3 (BSL3 facilities. This review summarizes the main achievements of WNV experimental research carried out in wild birds, highlighting advantages and limitations of this model. Viral and host factors that determine the infection outcome are analyzed in detail, as well as recent discoveries about avian immunity, viral transmission, and persistence achieved through experimental research. Studies of laboratory infections in the natural host will help to understand variations in susceptibility and reservoir competence among bird species, as well as in the epidemiological patterns found in different affected areas.

  8. Testosterone correlates with Venezuelan equine encephalitis virus infection in macaques

    Directory of Open Access Journals (Sweden)

    Koterski James

    2006-03-01

    Full Text Available Abstract Here we briefly report testosterone and cytokine responses to Venezuelan equine encephalitis virus (VEEV in macaques which were used as part of a larger study conducted by the Department of Defense to better characterize pathological responses to aerosolized VEEV in non-human primates. Serial samples were collected and analyzed for testosterone and cytokines prior to and during infection in 8 captive male macaques. Infected animals exhibited a febrile response with few significant changes in cytokine levels. Baseline testosterone levels were positively associated with viremia following exposure and were significantly higher than levels obtained during infection. Such findings suggest that disease-induced androgen suppression is a reasonable area for future study. Decreased androgen levels during physiological perturbations may function, in part, to prevent immunosuppression by high testosterone levels and to prevent the use of energetic resources for metabolically-expensive anabolic functions.

  9. Hepatitis C virus infection in hemodialysis patients in Maracaibo, Venezuela

    Directory of Open Access Journals (Sweden)

    Francisca Monsalve-Castillo

    2012-02-01

    Full Text Available Over a two year period, the incidence of hepatitis C virus (HCV infection was evaluated in 29 hemodialysis patients, aged between 15 and 75 years (mean ± SD: 45 ± 39.5 years, from the University Hospital Hemodyalisis Unit, Maracaibo, Zulia State, Venezuela. Anti-HCV antibodies were determined using a fourth generation ELISA (Innotest HCV Ab IV kit and positive blood samples were tested using a recombinant assay kit (Inno-LIA HCV Ab III, both kits from Innogenetics N.V., Belgium. The findings indicate a lack of HCV seroconversion in the hemodialysis patients over the study period, confirmed by the recombinant assay. Risk factors for HCV infection were 0.3270 (95% confidence interval: 0.01323-8.080 in patients undergoing hemodialysis. The findings suggest a lack of significant sources for HCV infection due to the preventive measures to avoid its transmission in the hemodialysis unit.

  10. Pulmonary disease in patients with human immunodeficiency virus infection

    DEFF Research Database (Denmark)

    Lundgren, J D; Orholm, Marianne; Lundgren, B;

    1989-01-01

    Pulmonary disease is the most important cause of morbidity and mortality in patients infected with human immunodeficiency virus (HIV). All parts of the hospital system are expected to be involved in the diagnosis and treatment of HIV infected patients in the coming years. Many different processes...... cause pulmonary disease alone or in combination. Bilateral interstitial infiltrates are the most frequent chest x-ray abnormality and are most frequently caused by infection with Pneumocystis carinii. Cytomegalovirus, Mycobacterium tuberculosis, nonspecific interstitial pneumonitis and pulmonary Kaposi......'s sarcoma are the most important parts of the differential diagnosis. An aggressive approach to the diagnosis of pulmonary disease in this patient population is indicated in order to provide optimal care and assess new therapies....

  11. Novel approaches towards conquering hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    Guo-Yi Wu; Hong-Song Chen

    2007-01-01

    Currently approved treatments for hepatitis B virus (HBV) infection include the immunomodulatory agent, IFN-a, and nucleos(t)ide analogues. Their efficacy is limited by their side effects, as well as the induction of viral mutations that render them less potent. It is thus necessary to develop drugs that target additional viral antigens. Chemicals and biomaterials by unique methods of preventing HBV replication are currently being developed, including novel nucleosides and newly synthesized compounds such as capsid assembling and mRNA transcription inhibitors. Molecular therapies that target different stages of the HBV life cycle will aid current methods to manage chronic hepatitis B (CHB) infection. The use of immunomodulators and gene therapy are also under consideration. This report summarizes the most recent treatment possibilities for CHB infection. Emerging therapies and their potential mechanisms, efficacy, and pitfalls are discussed.

  12. Infection with A2 Hong Kong influenza virus in domestic cats.

    Science.gov (United States)

    Paniker, C K; Nair, C M

    1970-01-01

    The antigenic relationship of A2 Hong Kong influenza virus with equine influenza virus, and its ability to infect horses and baboons, have led to studies on the susceptibility of domestic animals to the virus.In this study it was found that cats could be infected with A2 Hong Kong influenza virus by intranasal inoculation or by contact with an infected cat or with a human influenza patient. There was no clinical illness, but infected animals shed the virus from the throat for 1 week and developed haemagglutination-inhibiting antibodies. A survey of normal cat sera showed that 6 out of 28 sera inhibited haemagglutination by A2 Hong Kong influenza virus.The results suggest that domestic cats may act as vectors in the transmission of influenza virus. Experimental infection in cats may be used as a laboratory model for influenza.

  13. Infection with A2 Hong Kong influenza virus in domestic cats*

    Science.gov (United States)

    Paniker, C. K. J.; Nair, C. M. G.

    1970-01-01

    The antigenic relationship of A2 Hong Kong influenza virus with equine influenza virus, and its ability to infect horses and baboons, have led to studies on the susceptibility of domestic animals to the virus. In this study it was found that cats could be infected with A2 Hong Kong influenza virus by intranasal inoculation or by contact with an infected cat or with a human influenza patient. There was no clinical illness, but infected animals shed the virus from the throat for 1 week and developed haemagglutination-inhibiting antibodies. A survey of normal cat sera showed that 6 out of 28 sera inhibited haemagglutination by A2 Hong Kong influenza virus. The results suggest that domestic cats may act as vectors in the transmission of influenza virus. Experimental infection in cats may be used as a laboratory model for influenza. PMID:5314017

  14. Influenza A virus infection in zebrafish recapitulates mammalian infection and sensitivity to anti-influenza drug treatment

    OpenAIRE

    Gabor, Kristin A.; Michelle F. Goody; Mowel, Walter K; Breitbach, Meghan E.; Gratacap, Remi L.; P. Eckhard Witten; Kim, Carol H.

    2014-01-01

    Seasonal influenza virus infections cause annual epidemics and sporadic pandemics. These present a global health concern, resulting in substantial morbidity, mortality and economic burdens. Prevention and treatment of influenza illness is difficult due to the high mutation rate of the virus, the emergence of new virus strains and increasing antiviral resistance. Animal models of influenza infection are crucial to our gaining a better understanding of the pathogenesis of and host response to i...

  15. Occult hepatitis B virus infection and S gene escape mutants in HIV-infected patients after hepatitis B virus vaccination.

    Science.gov (United States)

    Aghakhani, Arezoo; Mohraz, Minoo; Aghasadeghi, Mohammad Reza; Banifazl, Mohammad; Vahabpour, Rouhollah; Karami, Afsaneh; Foroughi, Maryam; Ramezani, Amitis

    2016-10-01

    Hepatitis B virus (HBV) vaccination is recommended for HIV patients. Despite the relative success of HBV vaccination, breakthrough infections can occur infrequently in patients, and it can be due to occult HBV infection, vaccine unresponsiveness and/or emergence of escape mutants. This study assessed the presence of occult HBV infection and S gene escape mutants in HIV-positive patients after HBV vaccination. Ninety-two HIV-positive patients were enrolled in this study, including 52 responders to HBV vaccine and 40 non-responders. All of the cases received HBV vaccine according to routine HBV vaccination protocols. The presence of HBV-DNA was determined by real-time polymerase chain reaction (PCR). In HBV-DNA positive samples, the most conserved regions of S gene sequences were amplified by nested PCR and PCR products were sequenced. Occult HBV infection was detected in two cases. Glycine to arginine mutation at residue 145 (G145R) within the 'a' region of the S gene was detected in one of the occult HBV infection cases who was in the non-responder group. This study showed that the prevalence of occult HBV infection and vaccine escape mutants was low in our HBV-vaccinated HIV-positive patients in both responder and non-responder groups, so there was no alarming evidence indicating breakthrough HBV infection in our vaccinated HIV-positive cases.

  16. Proteomic analysis of primary duck hepatocytes infected with duck hepatitis B virus

    OpenAIRE

    Zhou Tianlun; Ye Rong; Lou Qiang; Zhou Shuangcheng; Xu Bin; Yan Liang; Zhou Xinwen; Qu Su; Ben Haijing; Zhao Yanfeng; Yang Pengyuan; Qu Di

    2010-01-01

    Abstract Background Hepatitis B virus (HBV) is a major cause of liver infection in human. Because of the lack of an appropriate cell culture system for supporting HBV infection efficiently, the cellular and molecular mechanisms of hepadnavirus infection remain incompletely understood. Duck heptatitis B virus (DHBV) can naturally infect primary duck hepatocytes (PDHs) that provide valuable model systems for studying hepadnavirus infection in vitro. In this report, we explored global changes in...

  17. Differential proteome analysis of chikungunya virus infection on host cells.

    Directory of Open Access Journals (Sweden)

    Christina Li-Ping Thio

    Full Text Available BACKGROUND: Chikungunya virus (CHIKV is an emerging mosquito-borne alphavirus that has caused multiple unprecedented and re-emerging outbreaks in both tropical and temperate countries. Despite ongoing research efforts, the underlying factors involved in facilitating CHIKV replication during early infection remains ill-characterized. The present study serves to identify host proteins modulated in response to early CHIKV infection using a proteomics approach. METHODOLOGY AND PRINCIPAL FINDINGS: The whole cell proteome profiles of CHIKV-infected and mock control WRL-68 cells were compared and analyzed using two-dimensional gel electrophoresis (2-DGE. Fifty-three spots were found to be differentially modulated and 50 were successfully identified by MALDI-TOF/TOF. Eight were significantly up-regulated and 42 were down-regulated. The mRNA expressions of 15 genes were also found to correlate with the corresponding protein expression. STRING network analysis identified several biological processes to be affected, including mRNA processing, translation, energy production and cellular metabolism, ubiquitin-proteasome pathway (UPP and cell cycle regulation. CONCLUSION/SIGNIFICANCE: This study constitutes a first attempt to investigate alteration of the host cellular proteome during early CHIKV infection. Our proteomics data showed that during early infection, CHIKV affected the expression of proteins that are involved in mRNA processing, host metabolic machinery, UPP, and cyclin-dependent kinase 1 (CDK1 regulation (in favour of virus survival, replication and transmission. While results from this study complement the proteomics results obtained from previous late host response studies, functional characterization of these proteins is warranted to reinforce our understanding of their roles during early CHIKV infection in humans.

  18. Mouse models of dengue virus infection for vaccine testing.

    Science.gov (United States)

    Sarathy, Vanessa V; Milligan, Gregg N; Bourne, Nigel; Barrett, Alan D T

    2015-12-10

    Dengue is a mosquito-borne disease caused by four serologically and genetically related viruses termed DENV-1 to DENV-4. With an annual global burden of approximately 390 million infections occurring in the tropics and subtropics worldwide, an effective vaccine to combat dengue is urgently needed. Historically, a major impediment to dengue research has been development of a suitable small animal infection model that mimics the features of human illness in the absence of neurologic disease that was the hallmark of earlier mouse models. Recent advances in immunocompromised murine infection models have resulted in development of lethal DENV-2, DENV-3 and DENV-4 models in AG129 mice that are deficient in both the interferon-α/β receptor (IFN-α/β R) and the interferon-γ receptor (IFN-γR). These models mimic many hallmark features of dengue disease in humans, such as viremia, thrombocytopenia, vascular leakage, and cytokine storm. Importantly AG129 mice develop lethal, acute, disseminated infection with systemic viral loads, which is characteristic of typical dengue illness. Infected AG129 mice generate an antibody response to DENV, and antibody-dependent enhancement (ADE) models have been established by both passive and maternal transfer of DENV-immune sera. Several steps have been taken to refine DENV mouse models. Viruses generated by peripheral in vivo passages incur substitutions that provide a virulent phenotype using smaller inocula. Because IFN signaling has a major role in immunity to DENV, mice that generate a cellular immune response are desired, but striking the balance between susceptibility to DENV and intact immunity is complicated. Great strides have been made using single-deficient IFN-α/βR mice for DENV-2 infection, and conditional knockdowns may offer additional approaches to provide a panoramic view that includes viral virulence and host immunity. Ultimately, the DENV AG129 mouse models result in reproducible lethality and offer multiple

  19. Occult persistence and lymphotropism of hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    Tram NQ Pham; Tomasz I Michalak

    2008-01-01

    Recent discovery of occult hepatitis C virus (HCV)infection persisting after spontaneous or antiviral therapy-induced resolution of hepatitis C was made possible by the introduction of nucleic acid amplification assays capable of detecting HCV RNA at sensitivities superseding those offered by clinical tests. Although individuals with this seemingly silent HCV infection are usually anti-HCV antibody reactive and have normal liver function tests, occult HCV infection has also been reported in anti-HCV-negative individuals with persistently elevated liver enzymes of unknown etiology. Studies have shown that HCV RNA can persist for years in serum, iymphomononuciear cells and liver in the absence of clinical symptoms, although histological evidence of a mild inflammatory liver injury can be occasionally encountered. Furthermore, while HCV RNA can be detected in circulating lymphoid cells in approximately 30% of cases, a short-term culture under stimulatory conditions augments HCV replication in these cells allowing detection of virus in otherwise HCV-negative cases. HCV infects different immune cell subsets, including CD4+ and CD8+ T lymphocytes, B cells and monocytes. Studies employing cional sequencing and single-stranded conformational polymorphism analyses have revealed unique HCV variants residing in immune cells, further strengthening the notion of HCV lymphotropism. Overall, the data accumulated suggest that occult HCV infection is a common consequence of resolution of symptomatic hepatitis C and that examination of the cells of the immune system is an effective approach to diagnosis of HCV infection and its long-term persistence. Further work is required to fully realize pathogenic and epidemiological consequences of occult HCV persistence.

  20. Inhibition of lytic infection of pseudorabies virus by arginine depletion

    International Nuclear Information System (INIS)

    Pseudorabies virus (PRV) is a member of Alphahepesviruses; it is an enveloped virus with a double-stranded DNA genome. Polyamines (such as spermine and spermidine) are ubiquitous in animal cells and participate in cellular proliferation and differentiation. Previous results of our laboratory showed that the PRV can accomplish lytic infection either in the presence of exogenous spermine (or spermidine) or depletion of cellular polyamines. The amino acid arginine is a precursor of polyamine biosynthesis. In this work, we investigated the role of arginine in PRV infection. It was found that the plaque formation of PRV was inhibited by arginase (enzyme catalyzing the conversion of arginine into ornithine and urea) treatment whereas this inhibition can be reversed by exogenous arginine, suggesting that arginine is essential for PRV proliferation. Western blotting was conducted to study the effect of arginine depletion on the levels of structural proteins of PRV in virus-infected cells. Four PRV structural proteins (gB, gE, UL47, and UL48) were chosen for examination, and results revealed that the levels of viral proteins were obviously reduced in long time arginase treatment. However, the overall protein synthesis machinery was apparently not influenced by arginase treatment either in mock or PRV-infected cells. Analyzing with native gel, we found that arginase treatment affected the mobility of PRV structural proteins, suggesting the conformational change of viral proteins by arginine depletion. Heat shock proteins, acting as molecular chaperons, participate in protein folding and translocation. Our results demonstrated that long time arginase treatment could reduce the expression of cellular heat shock proteins 70 (hsc70 and hsp70), and transcriptional suppression of heat shock protein 70 gene promoter was one of the mechanisms involved in this reduced expression

  1. [Antiretroviral therapy in human immunodeficiency virus infection: an update].

    Science.gov (United States)

    Chaix, F; Goujard, C

    2009-06-01

    Since the onset of the human immunodeficiency virus (HIV) epidemic, the care of infected patients improved dramatically. Whereas the disease was almost always fatal, the development of new drugs and new therapeutic strategies now allow a prolonged survival. However, the complexity of patient care is increasing and physicians face new clinical events and treatment toxicities. Recent molecules and follow-up according to the recent French recommendations will be presented here. The objectives of the treatment is to decrease mortality and morbidity of the HIV infection, by restoring near normal CD4+ T cell counts and qualitative T CD4+ responses, associated with a sustained reduction in viral replication. This objective must be reached by minimizing toxicity of antiretroviral drugs. Newly developed drugs that are better-tolerated and new therapeutic classes should improve outcome at all stages of HIV infection. Whereas viral eradication remains unrealistic and protective vaccines will not be soon available, direct consequences of long term HIV infection and issues related to an ageing HIV infected population raise up new research topics. Prevention of new infections, improvement in the precocity of care by a better-targeted screening and assessment of therapy before an established immune deficiency appear as the main priorities for the coming years. PMID:19237230

  2. Infection with Hepatitis C Virus among HIV-Infected Pregnant Women in Thailand

    Directory of Open Access Journals (Sweden)

    Denise J. Jamieson

    2008-01-01

    Full Text Available Objective. The purpose of this study was to describe the epidemiology of coinfection with hepatitis C virus (HCV and HIV among a cohort of pregnant Thai women. Methods. Samples from 1771 pregnant women enrolled in three vertical transmission of HIV studies in Bangkok, Thailand, were tested for HCV. Results. Among HIV-infected pregnant women, HCV seroprevelance was 3.8% and the active HCV infection rate was 3.0%. Among HIV-uninfected pregnant women, 0.3% were HCV-infected. Intravenous drug use by the woman was the factor most strongly associated with HCV seropositivity. Among 48 infants tested for HCV who were born to HIV/HCV coinfected women, two infants were HCV infected for an HCV transmission rate of 4.2% (95% 0.51–14.25%. Conclusions. HCV seroprevalence and perinatal transmission rates were low among this Thai cohort of HIV-infected pregnant women.

  3. Possible FDA-approved drugs to treat Ebola virus infection.

    Science.gov (United States)

    Yuan, Shu

    2015-01-01

    There is currently no effective treatment for the Ebola virus (EBOV) thus far. Most drugs and vaccines developed to date have not yet been approved for human trials. Two FDA-approved c-AbI1 tyrosine kinase inhibitors Gleevec and Tasigna block the release of viral particles; however, their clinical dosages are much lower than the dosages required for effective EBOV suppression. An α-1,2-glucosidase inhibitor Miglustat has been shown to inhibit EBOV particle assembly and secretion. Additionally, the estrogen receptor modulators Clomiphene and Toremifene prevent membrane fusion of EBOV and 50-90% of treated mice survived after Clomiphene/Toremifene treatments. However, the uptake efficiency of Clomiphene by oral administration is very low. Thus, I propose a hypothetical treatment protocol to treat Ebola virus infection with a cumulative use of both Miglustat and Toremifene to inhibit the virus effectively and synergistically. EBOV infection induces massive apoptosis of peripheral lymphocytes. Also, cytolysis of endothelial cells triggers disseminated intravascular coagulation (DIC) and subsequent multiple organ failures. Therefore, blood transfusions and active treatments with FDA-approved drugs to treat DIC are also recommended. PMID:25984303

  4. Zika virus infection-the next wave after dengue?

    Science.gov (United States)

    Wong, Samson Sai-Yin; Poon, Rosana Wing-Shan; Wong, Sally Cheuk-Ying

    2016-04-01

    Zika virus was initially discovered in east Africa about 70 years ago and remained a neglected arboviral disease in Africa and Southeast Asia. The virus first came into the limelight in 2007 when it caused an outbreak in Micronesia. In the ensuing decade, it spread widely in other Pacific islands, after which its incursion into Brazil in 2015 led to a widespread epidemic in Latin America. In most infected patients the disease is relatively benign. Serious complications include Guillain-Barré syndrome and congenital infection which may lead to microcephaly and maculopathy. Aedes mosquitoes are the main vectors, in particular, Ae. aegypti. Ae. albopictus is another potential vector. Since the competent mosquito vectors are highly prevalent in most tropical and subtropical countries, introduction of the virus to these areas could readily result in endemic transmission of the disease. The priorities of control include reinforcing education of travellers to and residents of endemic areas, preventing further local transmission by vectors, and an integrated vector management programme. The container habitats of Ae. aegypti and Ae. albopictus means engagement of the community and citizens is of utmost importance to the success of vector control. PMID:26965962

  5. Zika virus infection-the next wave after dengue?

    Science.gov (United States)

    Wong, Samson Sai-Yin; Poon, Rosana Wing-Shan; Wong, Sally Cheuk-Ying

    2016-04-01

    Zika virus was initially discovered in east Africa about 70 years ago and remained a neglected arboviral disease in Africa and Southeast Asia. The virus first came into the limelight in 2007 when it caused an outbreak in Micronesia. In the ensuing decade, it spread widely in other Pacific islands, after which its incursion into Brazil in 2015 led to a widespread epidemic in Latin America. In most infected patients the disease is relatively benign. Serious complications include Guillain-Barré syndrome and congenital infection which may lead to microcephaly and maculopathy. Aedes mosquitoes are the main vectors, in particular, Ae. aegypti. Ae. albopictus is another potential vector. Since the competent mosquito vectors are highly prevalent in most tropical and subtropical countries, introduction of the virus to these areas could readily result in endemic transmission of the disease. The priorities of control include reinforcing education of travellers to and residents of endemic areas, preventing further local transmission by vectors, and an integrated vector management programme. The container habitats of Ae. aegypti and Ae. albopictus means engagement of the community and citizens is of utmost importance to the success of vector control.

  6. TT virus infection and pancreatic cancer: Relationship or accidental coexistence

    Institute of Scientific and Technical Information of China (English)

    Krzysztof Tomasiewicz; Roma Modrzewska; Anna Lyczak; Grazyna Krawczuk

    2005-01-01

    TT virus (TTV) was first isolated in 1997 from the patient with acute post-transfusion hepatitis. This fact led to the conclusion that the virus was hepatotropic and could be one of the causative agents of acute hepatitis. Afterwards, however, the virus was found in other human tissues and serological studies revealed that it was widespread. Multiple tropisms of TTV and the fact of its high incidence in general population are considered to indicate no medical significance of TTV in human pathology. Here we present a report of two cases of TTV infection in patients who developed pancreas cancer. The patients were hospitalized at the Department of Infectious Diseases due to hepatitis of unknown origin. Since serological and virological markers of common primary and secondary hepatotropic viruses were negative, TTV-DNA was found in serum and was believed to be the only causative agent with probable hepatotropic action. The patients later developed pancreas cancer and they underwent operation. The relationship is difficult to confirm, however the cases we present should be treated as a preliminary report and a comment on the real role of TTV in human pathology.

  7. Bilateral Linear Lichen Planus Pigmentosus Associated with Hepatitis C Virus Infection

    Directory of Open Access Journals (Sweden)

    Vasanop Vachiramon

    2010-09-01

    Full Text Available Lichen planus pigmentosus is a rare subtype of lichen planus. We report a first case of lichen planus pigmentosus with bilateral linear distribution associated with hepatitis C virus infection. The lesion was improved after sun avoidance and treatment of hepatitis C virus infection with a combination of interferon and ribavirin. This case stresses the importance of screening for hepatitis C virus infection as lichen planus pigmentosus can be an associated condition.

  8. Trend of dengue virus infection at Lucknow, north India (2008- 2010): A hospital based study

    OpenAIRE

    Pandey, Nidhi; Nagar, Rachna; Gupta, Shikha; Omprakash,; Khan, Danish; Singh, Desh Deepak; Mishra, Gitika; Prakash, Shantanu; Singh, K. P.; Singh, Mastan; Jain, Amita

    2012-01-01

    Background & objectives: Dengue virus (DV) infection has emerged as a major health problem in north India. Here, we report the annual trend of dengue virus infection as seen in Lucknow, Uttar Pradesh, during 2008-2010. Methods: Blood samples from clinically suspected cases of dengue virus infection were collected and history was taken on structured clinical data sheet. All samples were tested for dengue IgM by antibody capture ELISA. Selected samples were tested by conventional RT-PCR for den...

  9. Virus-specific antibodies allow viral replication in the marginal zone, thereby promoting CD8+ T-cell priming and viral control

    Science.gov (United States)

    Duhan, Vikas; Khairnar, Vishal; Friedrich, Sarah-Kim; Zhou, Fan; Gassa, Asmae; Honke, Nadine; Shaabani, Namir; Gailus, Nicole; Botezatu, Lacramioara; Khandanpour, Cyrus; Dittmer, Ulf; Häussinger, Dieter; Recher, Mike; Hardt, Cornelia; Lang, Philipp A.; Lang, Karl S.

    2016-01-01

    Clinically used human vaccination aims to induce specific antibodies that can guarantee long-term protection against a pathogen. The reasons that other immune components often fail to induce protective immunity are still debated. Recently we found that enforced viral replication in secondary lymphoid organs is essential for immune activation. In this study we used the lymphocytic choriomeningitis virus (LCMV) to determine whether enforced virus replication occurs in the presence of virus-specific antibodies or virus-specific CD8+ T cells. We found that after systemic recall infection with LCMV-WE the presence of virus-specific antibodies allowed intracellular replication of virus in the marginal zone of spleen. In contrast, specific antibodies limited viral replication in liver, lung, and kidney. Upon recall infection with the persistent virus strain LCMV-Docile, viral replication in spleen was essential for the priming of CD8+ T cells and for viral control. In contrast to specific antibodies, memory CD8+ T cells inhibited viral replication in marginal zone but failed to protect mice from persistent viral infection. We conclude that virus-specific antibodies limit viral infection in peripheral organs but still allow replication of LCMV in the marginal zone, a mechanism that allows immune boosting during recall infection and thereby guarantees control of persistent virus. PMID:26805453

  10. Virus-specific antibodies allow viral replication in the marginal zone, thereby promoting CD8(+) T-cell priming and viral control.

    Science.gov (United States)

    Duhan, Vikas; Khairnar, Vishal; Friedrich, Sarah-Kim; Zhou, Fan; Gassa, Asmae; Honke, Nadine; Shaabani, Namir; Gailus, Nicole; Botezatu, Lacramioara; Khandanpour, Cyrus; Dittmer, Ulf; Häussinger, Dieter; Recher, Mike; Hardt, Cornelia; Lang, Philipp A; Lang, Karl S

    2016-01-01

    Clinically used human vaccination aims to induce specific antibodies that can guarantee long-term protection against a pathogen. The reasons that other immune components often fail to induce protective immunity are still debated. Recently we found that enforced viral replication in secondary lymphoid organs is essential for immune activation. In this study we used the lymphocytic choriomeningitis virus (LCMV) to determine whether enforced virus replication occurs in the presence of virus-specific antibodies or virus-specific CD8(+) T cells. We found that after systemic recall infection with LCMV-WE the presence of virus-specific antibodies allowed intracellular replication of virus in the marginal zone of spleen. In contrast, specific antibodies limited viral replication in liver, lung, and kidney. Upon recall infection with the persistent virus strain LCMV-Docile, viral replication in spleen was essential for the priming of CD8(+) T cells and for viral control. In contrast to specific antibodies, memory CD8(+) T cells inhibited viral replication in marginal zone but failed to protect mice from persistent viral infection. We conclude that virus-specific antibodies limit viral infection in peripheral organs but still allow replication of LCMV in the marginal zone, a mechanism that allows immune boosting during recall infection and thereby guarantees control of persistent virus. PMID:26805453

  11. Early events associated with infection of Epstein-Barr virus infection of primary B-cells.

    Directory of Open Access Journals (Sweden)

    Sabyasachi Halder

    Full Text Available Epstein Barr virus (EBV is closely associated with the development of a vast number of human cancers. To develop a system for monitoring early cellular and viral events associated with EBV infection a self-recombining BAC containing 172-kb of the Epstein Barr virus genome BAC-EBV designated as MD1 BAC (Chen et al., 2005, J.Virology was used to introduce an expression cassette of green fluorescent protein (GFP by homologous recombination, and the resultant BAC clone, BAC-GFP-EBV was transfected into the HEK 293T epithelial cell line. The resulting recombinant GFP EBV was induced to produce progeny virus by chemical inducer from the stable HEK 293T BAC GFP EBV cell line and the virus was used to immortalize human primary B-cell as monitored by green fluorescence and outgrowth of the primary B cells. The infection, B-cell activation and cell proliferation due to GFP EBV was monitored by the expression of the B-cell surface antigens CD5, CD10, CD19, CD23, CD39, CD40 , CD44 and the intercellular proliferation marker Ki-67 using Flow cytometry. The results show a dramatic increase in Ki-67 which continues to increase by 6-7 days post-infection. Likewise, CD40 signals showed a gradual increase, whereas CD23 signals were increased by 6-12 hours, maximally by 3 days and then decreased. Monitoring the viral gene expression pattern showed an early burst of lytic gene expression. This up-regulation of lytic gene expression prior to latent genes during early infection strongly suggests that EBV infects primary B-cell with an initial burst of lytic gene expression and the resulting progeny virus is competent for infecting new primary B-cells. This process may be critical for establishment of latency prior to cellular transformation. The newly infected primary B-cells can be further analyzed for investigating B cell activation due to EBV infection.

  12. Zika Virus Infection in Mice Causes Panuveitis with Shedding of Virus in Tears

    Directory of Open Access Journals (Sweden)

    Jonathan J. Miner

    2016-09-01

    Full Text Available Zika virus (ZIKV is an emerging flavivirus that causes congenital abnormalities and Guillain-Barré syndrome. ZIKV infection also results in severe eye disease characterized by optic neuritis, chorioretinal atrophy, and blindness in newborns and conjunctivitis and uveitis in adults. We evaluated ZIKV infection of the eye by using recently developed mouse models of pathogenesis. ZIKV-inoculated mice developed conjunctivitis, panuveitis, and infection of the cornea, iris, optic nerve, and ganglion and bipolar cells in the retina. This phenotype was independent of the entry receptors Axl or Mertk, given that Axl−/−, Mertk−/−, and Axl−/−Mertk−/− double knockout mice sustained levels of infection similar to those of control animals. We also detected abundant viral RNA in tears, suggesting that virus might be secreted from lacrimal glands or shed from the cornea. This model provides a foundation for studying ZIKV-induced ocular disease, defining mechanisms of viral persistence, and developing therapeutic approaches for viral infections of the eye.

  13. Dengue virus sero-cross-reactivity drives antibody-dependent enhancement of infection with zika virus.

    Science.gov (United States)

    Dejnirattisai, Wanwisa; Supasa, Piyada; Wongwiwat, Wiyada; Rouvinski, Alexander; Barba-Spaeth, Giovanna; Duangchinda, Thaneeya; Sakuntabhai, Anavaj; Cao-Lormeau, Van-Mai; Malasit, Prida; Rey, Felix A; Mongkolsapaya, Juthathip; Screaton, Gavin R

    2016-09-01

    Zika virus (ZIKV) was discovered in 1947 and was thought to lead to relatively mild disease. The recent explosive outbreak of ZIKV in South America has led to widespread concern, with reports of neurological sequelae ranging from Guillain Barré syndrome to microcephaly. ZIKV infection has occurred in areas previously exposed to dengue virus (DENV), a flavivirus closely related to ZIKV. Here we investigated the serological cross-reaction between the two viruses. Plasma immune to DENV showed substantial cross-reaction to ZIKV and was able to drive antibody-dependent enhancement (ADE) of ZIKV infection. Using a panel of human monoclonal antibodies (mAbs) to DENV, we showed that most antibodies that reacted to DENV envelope protein also reacted to ZIKV. Antibodies to linear epitopes, including the immunodominant fusion-loop epitope, were able to bind ZIKV but were unable to neutralize the virus and instead promoted ADE. Our data indicate that immunity to DENV might drive greater ZIKV replication and have clear implications for disease pathogenesis and future vaccine programs for ZIKV and DENV. PMID:27339099

  14. Interleukin 28B genetic polymorphism and hepatitis B virus infection.

    Science.gov (United States)

    Takahashi, Toru

    2014-09-14

    Interleukin (IL) 28B genetic polymorphism is significantly associated with the sustained virological response rate in patients with chronic hepatitis C treated with pegylated interferon-α (PEG-IFN) plus ribavirin and with spontaneous hepatitis C virus clearance. However, a consensus on the relationship between IL28B genetic polymorphism and the favorable outcome of chronic hepatitis B virus infection defined by hepatitis B e antigen seroconversion, and/or hepatitis B surface antigen seroclearance in patients treated with interferon or PEG-IFN has not been reached. Several reports failed to show a positive association, while some studies demonstrated a positive association in certain subject settings. More prospective studies including large cohorts are needed to determine the possible association between IL28B genetic polymorphism and the outcome of interferon or PEG-IFN treatment for chronic hepatitis B.

  15. Systems biology unravels interferon responses to respiratory virus infections

    Institute of Scientific and Technical Information of China (English)

    Andrea; L; Kroeker; Kevin; M; Coombs

    2014-01-01

    Interferon production is an important defence against viral replication and its activation is an attractive therapeutic target. However, it has long been known that viruses perpetually evolve a multitude of strategies to evade these host immune responses. In recent years there has been an explosion of information on virusinduced alterations of the host immune response that have resulted from data-rich omics technologies. Unravelling how these systems interact and determining the overall outcome of the host response to viral infection will play an important role in future treatment and vaccine development. In this review we focus primarily on the interferon pathway and its regulation as well as mechanisms by which respiratory RNA viruses interfere with its signalling capacity.

  16. A Susceptible Mouse Model for Zika Virus Infection.

    Science.gov (United States)

    Dowall, Stuart D; Graham, Victoria A; Rayner, Emma; Atkinson, Barry; Hall, Graham; Watson, Robert J; Bosworth, Andrew; Bonney, Laura C; Kitchen, Samantha; Hewson, Roger

    2016-05-01

    Zika virus (ZIKV) is a mosquito-borne pathogen which has recently spread beyond Africa and into Pacific and South American regions. Despite first being detected in 1947, very little information is known about the virus, and its spread has been associated with increases in Guillain-Barre syndrome and microcephaly. There are currently no known vaccines or antivirals against ZIKV infection. Progress in assessing interventions will require the development of animal models to test efficacies; however, there are only limited reports on in vivo studies. The only susceptible murine models have involved intracerebral inoculations or juvenile animals, which do not replicate natural infection. Our report has studied the effect of ZIKV infection in type-I interferon receptor deficient (A129) mice and the parent strain (129Sv/Ev) after subcutaneous challenge in the lower leg to mimic a mosquito bite. A129 mice developed severe symptoms with widespread viral RNA detection in the blood, brain, spleen, liver and ovaries. Histological changes were also striking in these animals. 129Sv/Ev mice developed no clinical symptoms or histological changes, despite viral RNA being detectable in the blood, spleen and ovaries, albeit at lower levels than those seen in A129 mice. Our results identify A129 mice as being highly susceptible to ZIKV and thus A129 mice represent a suitable, and urgently required, small animal model for the testing of vaccines and antivirals. PMID:27149521

  17. Epidemiological changes of respiratory syncytial virus (RSV infections in Israel.

    Directory of Open Access Journals (Sweden)

    Shira Hirsh

    Full Text Available RSV is the leading cause of lower respiratory-tract infections in infants and therefore demands in-depth epidemiological characterization. We investigated here the distribution of RSV types in Israel between the years 2005-2012. Clinical samples were collected from 11,018 patients hospitalized due to respiratory illnesses and were evaluated for the presence of various respiratory viruses, including RSV A and RSV B. Until 2008, each year was characterized by the presence of one dominant type of RSV. However, from 2008, both RSV A and B types were detected at significant levels, particularly among infants aged 0-2 years. Furthermore, significant changes in the RSV A and RSV B subtypes circulating in Israel since 2008 were observed. Finally, we demonstrate that, irrespectively of the changes observed in RSV epidemiology, when the pandemic H1N1pdm09 influenza virus appeared in 2009, RSV infections were delayed and were detected when infection with H1N1pdm09 had declined.

  18. A Susceptible Mouse Model for Zika Virus Infection.

    Directory of Open Access Journals (Sweden)

    Stuart D Dowall

    2016-05-01

    Full Text Available Zika virus (ZIKV is a mosquito-borne pathogen which has recently spread beyond Africa and into Pacific and South American regions. Despite first being detected in 1947, very little information is known about the virus, and its spread has been associated with increases in Guillain-Barre syndrome and microcephaly. There are currently no known vaccines or antivirals against ZIKV infection. Progress in assessing interventions will require the development of animal models to test efficacies; however, there are only limited reports on in vivo studies. The only susceptible murine models have involved intracerebral inoculations or juvenile animals, which do not replicate natural infection. Our report has studied the effect of ZIKV infection in type-I interferon receptor deficient (A129 mice and the parent strain (129Sv/Ev after subcutaneous challenge in the lower leg to mimic a mosquito bite. A129 mice developed severe symptoms with widespread viral RNA detection in the blood, brain, spleen, liver and ovaries. Histological changes were also striking in these animals. 129Sv/Ev mice developed no clinical symptoms or histological changes, despite viral RNA being detectable in the blood, spleen and ovaries, albeit at lower levels than those seen in A129 mice. Our results identify A129 mice as being highly susceptible to ZIKV and thus A129 mice represent a suitable, and urgently required, small animal model for the testing of vaccines and antivirals.

  19. Gastrointestinal opportunistic infections in human immunodeficiency virus disease

    Directory of Open Access Journals (Sweden)

    Al Anazi Awadh

    2009-01-01

    Full Text Available Gastrointestinal (GI opportunistic infections (OIs are commonly encountered at various stages of human immunodeficiency virus (HIV disease. In view of the suppressive nature of the virus and the direct contact with the environment, the GI tract is readily accessible and is a common site for clinical expression of HIV. The subject is presented based on information obtained by electronic searches of peer-reviewed articles in medical journals, Cochrane reviews and PubMed sources. The spectrum of GI OIs ranges from oral lesions of Candidiasis, various lesions of viral infections, hepatobiliary lesions, pancreatitis and anorectal lesions. The manifestations of the disease depend on the level of immunosuppression, as determined by the CD4 counts. The advent of highly active antiretroviral therapy has altered the pattern of presentation, resorting mainly to features of antimicrobial-associated colitis and side effects of antiretroviral drugs. The diagnosis of GI OIs in HIV/ acquired immunodeficiency syndrome patients is usually straightforward. However, subtle presentations require that the physicians should have a high index of suspicion when given the setting of HIV infection.

  20. A Susceptible Mouse Model for Zika Virus Infection.

    Science.gov (United States)

    Dowall, Stuart D; Graham, Victoria A; Rayner, Emma; Atkinson, Barry; Hall, Graham; Watson, Robert J; Bosworth, Andrew; Bonney, Laura C; Kitchen, Samantha; Hewson, Roger

    2016-05-01

    Zika virus (ZIKV) is a mosquito-borne pathogen which has recently spread beyond Africa and into Pacific and South American regions. Despite first being detected in 1947, very little information is known about the virus, and its spread has been associated with increases in Guillain-Barre syndrome and microcephaly. There are currently no known vaccines or antivirals against ZIKV infection. Progress in assessing interventions will require the development of animal models to test efficacies; however, there are only limited reports on in vivo studies. The only susceptible murine models have involved intracerebral inoculations or juvenile animals, which do not replicate natural infection. Our report has studied the effect of ZIKV infection in type-I interferon receptor deficient (A129) mice and the parent strain (129Sv/Ev) after subcutaneous challenge in the lower leg to mimic a mosquito bite. A129 mice developed severe symptoms with widespread viral RNA detection in the blood, brain, spleen, liver and ovaries. Histological changes were also striking in these animals. 129Sv/Ev mice developed no clinical symptoms or histological changes, despite viral RNA being detectable in the blood, spleen and ovaries, albeit at lower levels than those seen in A129 mice. Our results identify A129 mice as being highly susceptible to ZIKV and thus A129 mice represent a suitable, and urgently required, small animal model for the testing of vaccines and antivirals.

  1. Within-host spatiotemporal dynamics of plant virus infection at the cellular level.

    Directory of Open Access Journals (Sweden)

    Nicolas Tromas

    2014-02-01

    Full Text Available A multicellular organism is not a monolayer of cells in a flask; it is a complex, spatially structured environment, offering both challenges and opportunities for viruses to thrive. Whereas virus infection dynamics at the host and within-cell levels have been documented, the intermediate between-cell level remains poorly understood. Here, we used flow cytometry to measure the infection status of thousands of individual cells in virus-infected plants. This approach allowed us to determine accurately the number of cells infected by two virus variants in the same host, over space and time as the virus colonizes the host. We found a low overall frequency of cellular infection (<0.3, and few cells were coinfected by both virus variants (<0.1. We then estimated the cellular contagion rate (R, the number of secondary infections per infected cell per day. R ranged from 2.43 to values not significantly different from zero, and generally decreased over time. Estimates of the cellular multiplicity of infection (MOI, the number of virions infecting a cell, were low (<1.5. Variance of virus-genotype frequencies increased strongly from leaf to cell levels, in agreement with a low MOI. Finally, there were leaf-dependent differences in the ease with which a leaf could be colonized, and the number of virions effectively colonizing a leaf. The modeling of infection patterns suggests that the aggregation of virus-infected cells plays a key role in limiting spread; matching the observation that cell-to-cell movement of plant viruses can result in patches of infection. Our results show that virus expansion at the between-cell level is restricted, probably due to the host environment and virus infection itself.

  2. Effects of single and double infections with Potato virus X and Tobacco mosaic virus on disease development, plant growth, and virus accumulation in tomato

    OpenAIRE

    BALOGUN OLUSEGUN S.; XU LEIXIN; TERAOKA TOHRU; HOSOKAWA DAIJIRO

    2002-01-01

    The tomato cv. Fukuju nº. 2 was used for studying the effect of single and double infections with Potato virus X (PVX) and Tobacco mosaic virus (TMV). Mixed infection resulted in a synergistic increase of disease severity, where more growth reduction was seen with simultaneous inoculations than with sequential inoculations at four-day intervals. At five and 12 days post-inoculation, the increased severity of the disease coincided with enhancement of virus accumulation in the rapidly expanding...

  3. Respiratory Syncytial Virus Infections in Infants: Detel1ninants of Clinical Severity

    OpenAIRE

    Brandenburg, Afke

    2000-01-01

    textabstractIn 1955 a virus was isolated by Morris et al. from a chimpanzee with an upper respiratory tract infection. This apparently new virus was originally called chimpanzee coryza agent. Soon aftclwards, when it was isolated from children with respiratory disease, it became clear that this virus was a major human pathogen. The virus was from then onward called respiratory syncytial virus (RSV) because of its ability to caLise respiratory disease and to induce large syncytia in cell cultu...

  4. Isolation and identification of African horsesickness virus from naturally infected dogs in Upper Egypt.

    OpenAIRE

    Salama, S.A.; Dardiri, A. H.; Awad, F. I.; A. M. Soliman; M.M Amin

    1981-01-01

    African horsesickness virus was isolated from blood samples of street dogs in Aswan Province in Arab Republic of Egypt. Of six isolated "dog strain" African horsesickness viruses, three viruses designated D2, D6 and D10 have been identified as type 9 African horsesickness virus. Methods of isolation, tissue culture adaptation, serological indentification and typing are described. Horses experimentally infected with dog viruses showed febrile reaction and characteristic clinical and pathologic...

  5. Additive interactions of unrelated viruses in mixed infections of cowpea (Vigna unguiculata L. Walp).

    Science.gov (United States)

    Nsa, Imade Y; Kareem, Kehinde T

    2015-01-01

    This study was carried out to determine the effects of single infections and co-infections of three unrelated viruses on three cowpea cultivars (one commercial cowpea cultivar "White" and 2 IITA lines; IT81D-985 and TVu 76). The plants were inoculated with Cowpea aphid-borne mosaic virus (CABMV), genus Potyvirus, Cowpea mottle virus (CMeV), genus Carmovirus and Southern bean mosaic virus (SBMV), genus Sobemovirus singly and in mixture (double and triple) at 10, 20, and 30 days after planting (DAP). The treated plants were assessed for susceptibility to the viruses, growth, and yield. In all cases of infection, early inoculation resulted in higher disease severity compared with late infection. The virus treated cowpea plants were relatively shorter than buffer inoculated control plants except the IT81D-985 plants that were taller and produced more foliage. Single infections by CABMV, CMeV, and SBMV led to a complete loss of seeds in the three cowpea cultivars at 10 DAP; only cultivar White produced some seeds at 30 DAP. Double and triple virus infections led to a total loss of seeds in all three cowpea cultivars. None of the virus infected IITA lines produced any seeds except IT81D-985 plants co-infected with CABMV and SBMV at 30 DAP with a reduction of 80%. Overall, the commercial cultivar "White" was the least susceptible to the virus treatments and produced the most yield (flowers, pods, and seeds). CABMV was the most aggressive of these viruses and early single inoculations with this virus resulted in the premature death of some of the seedlings. The presence of the Potyvirus, CABMV in the double virus infections did not appear to increase disease severity or yield loss. There was no strong evidence for synergistic interactions between the viruses in the double virus mixtures. PMID:26483824

  6. Serum Ferritin as a Predictor of Host Response to Hepatitis B Virus Infection

    Science.gov (United States)

    Lustbader, Edward D.; Hann, Hie-Won L.; Blumberg, Baruch S.

    1983-04-01

    With hemodialysis patients, a high serum ferritin before there was serological evidence of hepatitis B virus infection increased the likelihood that the infection would be persistent. This finding suggested that hepatitis B virus is likely to infect and actively replicate in liver cells with the propensity for increased ferritin synthesis. The virus itself could stimulate the synthesis of ferritin in a cyclic positive feedback mechanism that increases intracellular ferritin concentration and, eventually, intracellular iron. Transformed liver cells have low iron content, do not replicate hepatitis B virus, and require iron for growth. Infected, nonmalignant liver cells could supply iron to the transformed cells and nourish their expansion.

  7. Quantifying homologous and heterologous antibody titre rises after influenza virus infection.

    Science.gov (United States)

    Freeman, G; Perera, R A P M; Ngan, E; Fang, V J; Cauchemez, S; Ip, D K M; Peiris, J S M; Cowling, B J

    2016-08-01

    Most influenza virus infections are associated with mild disease. One approach to estimate the occurrence of influenza virus infections in individuals is via repeated measurement of humoral antibody titres. We used baseline and convalescent antibody titres measured by haemagglutination inhibition (HI) and viral neutralization (VN) assays against influenza A(H1N1), A(H3N2) and B viruses to investigate the characteristics of antibody rises following virologically confirmed influenza virus infections in participants in a community-based study. Multivariate models were fitted in a Bayesian framework to characterize the distribution of changes in antibody titres following influenza A virus infections. In 122 participants with PCR-confirmed influenza A virus infection, homologous antibody titres rose by geometric means of 1·2- to 10·2-fold after infection with A(H1N1), A(H3N2) and A(H1N1)pdm09. Significant cross-reactions were observed between A(H1N1)pdm09 and seasonal A(H1N1). Antibody titre rises for some subtypes and assays varied by age, receipt of oseltamivir treatment, and recent receipt of influenza vaccination. In conclusion, we provided a quantitative description of the mean and variation in rises in influenza virus antibody titres following influenza virus infection. The multivariate patterns in boosting of antibody titres following influenza virus infection could be taken into account to improve estimates of cumulative incidence of infection in seroepidemiological studies. PMID:27018720

  8. The role of shrimp miR-965 in virus infection.

    Science.gov (United States)

    Shu, Le; Li, Changrun; Zhang, Xiaobo

    2016-07-01

    RNAi, mediated by microRNAs (miRNAs), has attracted increasing attention for its important role in cross-talk between host and virus. However, the role of host miRNA in the virus infection in vivo has not been intensively investigated. In this study, the effects of a shrimp miRNA (miR-965) on the white spot syndrome virus (WSSV) infection were characterized. The results indicated that the expression of miR-965 was significantly upregulated in shrimp in response to the WSSV challenge, suggesting its involvement in the virus infection. The miR-965 silencing led to significant increases of WSSV copies and virus-infected shrimp mortality, while the miR-965 overexpression resulted in the decreased WSSV copies and virus-infected shrimp mortality, indicating that miR-965 played a negative role in the WSSV infection. The further data revealed that miR-965 inhibited the virus infection by targeting the viral wsv240 gene, an important gene required for the WSSV infection in shrimp. The results demonstrated that miR-965 could promote the shrimp phagocytosis against virus infection by targeting the shrimp ATG5 (autophagy related 5) gene. Therefore, our findings presented novel evidence to better understand the anfractuous host-virus interactions in vivo.

  9. Human antibody responses after dengue virus infection are highly cross-reactive to Zika virus

    Science.gov (United States)

    Priyamvada, Lalita; Quicke, Kendra M.; Hudson, William H.; Onlamoon, Nattawat; Sewatanon, Jaturong; Edupuganti, Srilatha; Pattanapanyasat, Kovit; Chokephaibulkit, Kulkanya; Mulligan, Mark J.; Wilson, Patrick C.; Ahmed, Rafi; Suthar, Mehul S.; Wrammert, Jens

    2016-01-01

    Zika virus (ZIKV) is an emerging mosquito-borne flavivirus of significant public health concern. ZIKV shares a high degree of sequence and structural homology compared with other flaviviruses, including dengue virus (DENV), resulting in immunological cross-reactivity. Improving our current understanding of the extent and characteristics of this immunological cross-reactivity is important, as ZIKV is presently circulating in areas that are highly endemic for dengue. To assess the magnitude and functional quality of cross-reactive immune responses between these closely related viruses, we tested acute and convalescent sera from nine Thai patients with PCR-confirmed DENV infection against ZIKV. All of the sera tested were cross-reactive with ZIKV, both in binding and in neutralization. To deconstruct the observed serum cross-reactivity in depth, we also characterized a panel of DENV-specific plasmablast-derived monoclonal antibodies (mAbs) for activity against ZIKV. Nearly half of the 47 DENV-reactive mAbs studied bound to both whole ZIKV virion and ZIKV lysate, of which a subset also neutralized ZIKV. In addition, both sera and mAbs from the dengue-infected patients enhanced ZIKV infection of Fc gamma receptor (FcγR)-bearing cells in vitro. Taken together, these findings suggest that preexisting immunity to DENV may impact protective immune responses against ZIKV. In addition, the extensive cross-reactivity may have implications for ZIKV virulence and disease severity in DENV-experienced populations. PMID:27354515

  10. Human antibody responses after dengue virus infection are highly cross-reactive to Zika virus.

    Science.gov (United States)

    Priyamvada, Lalita; Quicke, Kendra M; Hudson, William H; Onlamoon, Nattawat; Sewatanon, Jaturong; Edupuganti, Srilatha; Pattanapanyasat, Kovit; Chokephaibulkit, Kulkanya; Mulligan, Mark J; Wilson, Patrick C; Ahmed, Rafi; Suthar, Mehul S; Wrammert, Jens

    2016-07-12

    Zika virus (ZIKV) is an emerging mosquito-borne flavivirus of significant public health concern. ZIKV shares a high degree of sequence and structural homology compared with other flaviviruses, including dengue virus (DENV), resulting in immunological cross-reactivity. Improving our current understanding of the extent and characteristics of this immunological cross-reactivity is important, as ZIKV is presently circulating in areas that are highly endemic for dengue. To assess the magnitude and functional quality of cross-reactive immune responses between these closely related viruses, we tested acute and convalescent sera from nine Thai patients with PCR-confirmed DENV infection against ZIKV. All of the sera tested were cross-reactive with ZIKV, both in binding and in neutralization. To deconstruct the observed serum cross-reactivity in depth, we also characterized a panel of DENV-specific plasmablast-derived monoclonal antibodies (mAbs) for activity against ZIKV. Nearly half of the 47 DENV-reactive mAbs studied bound to both whole ZIKV virion and ZIKV lysate, of which a subset also neutralized ZIKV. In addition, both sera and mAbs from the dengue-infected patients enhanced ZIKV infection of Fc gamma receptor (FcγR)-bearing cells in vitro. Taken together, these findings suggest that preexisting immunity to DENV may impact protective immune responses against ZIKV. In addition, the extensive cross-reactivity may have implications for ZIKV virulence and disease severity in DENV-experienced populations. PMID:27354515

  11. Seroprevalence of hepatitis B virus and hepatitis C virus co-infection in human immunodeficiency virus infected patients at a tertiary care hospital in South India

    Directory of Open Access Journals (Sweden)

    C. Siva Kalyani

    2015-08-01

    Results: Out of 100 HIV positive patients in the study group 12(12% were co infected with HBV and 2(2% were co infected with HCV. Out of 12 HIV and HBV co infected patients 7(58.3% were females and 5(41.7% were males. The HIV and HCV co infected patients were both females. Co infection of HBV and HCV with HIV was found to be 0(0%. Co infection was most commonly seen in the age group 31-40 years followed by 21 and ndash; 39 years. In the control group out of 100 HIV negative individuals, 1(1% was infected with HBV infection. Conclusions: The routine screening of HBV and HCV should be mandatory for HIV infected patients, as there is more chance of co infection with these Hepatitis viruses due to enhanced immunodeficiency by HIV and similar routes of transmission. Clear National policies should be established which should include clear economic and health care strategies to improve quality of living conditions, education and easy access to health care facilities. [Int J Res Med Sci 2015; 3(8.000: 2041-2045

  12. Circulating microRNA profiles of Ebola virus infection

    Science.gov (United States)

    Duy, Janice; Koehler, Jeffrey W.; Honko, Anna N.; Schoepp, Randal J.; Wauquier, Nadia; Gonzalez, Jean-Paul; Pitt, M. Louise; Mucker, Eric M.; Johnson, Joshua C.; O’Hearn, Aileen; Bangura, James; Coomber, Moinya; Minogue, Timothy D.

    2016-01-01

    Early detection of Ebola virus (EBOV) infection is essential to halting transmission and adjudicating appropriate treatment. However, current methods rely on viral identification, and this approach can misdiagnose presymptomatic and asymptomatic individuals. In contrast, disease-driven alterations in the host transcriptome can be exploited for pathogen-specific diagnostic biomarkers. Here, we present for the first time EBOV-induced changes in circulating miRNA populations of nonhuman primates (NHPs) and humans. We retrospectively profiled longitudinally-collected plasma samples from rhesus macaques challenged via intramuscular and aerosol routes and found 36 miRNAs differentially present in both groups. Comparison of miRNA abundances to viral loads uncovered 15 highly correlated miRNAs common to EBOV-infected NHPs and humans. As proof of principle, we developed an eight-miRNA classifier that correctly categorized infection status in 64/74 (86%) human and NHP samples. The classifier identified acute infections in 27/29 (93.1%) samples and in 6/12 (50%) presymptomatic NHPs. These findings showed applicability of NHP-derived miRNAs to a human cohort, and with additional research the resulting classifiers could impact the current capability to diagnose presymptomatic and asymptomatic EBOV infections. PMID:27098369

  13. Antioxidants: potential antiviral agents for Japanese encephalitis virus infection.

    Science.gov (United States)

    Zhang, Yu; Wang, Zehua; Chen, Huan; Chen, Zongtao; Tian, Yanping

    2014-07-01

    Japanese encephalitis (JE) is prevalent throughout eastern and southern Asia and the Pacific Rim. It is caused by the JE virus (JEV), which belongs to the family Flaviviridae. Despite the importance of JE, little is known about its pathogenesis. The role of oxidative stress in the pathogenesis of viral infections has led to increased interest in its role in JEV infections. This review focuses mainly on the role of oxidative stress in the pathogenesis of JEV infection and the antiviral effect of antioxidant agents in inhibiting JEV production. First, this review summarizes the pathogenesis of JE. The pathological changes include neuronal death, astrocyte activation, and microglial proliferation. Second, the relationship between oxidative stress and JEV infection is explored. JEV infection induces the generation of oxidants and exhausts the supply of antioxidants, which activates specific signaling pathways. Finally, the therapeutic efficacy of a variety of antioxidants as antiviral agents, including minocycline, arctigenin, fenofibrate, and curcumin, was studied. In conclusion, antioxidants are likely to be developed into antiviral agents for the treatment of JE. PMID:24780919

  14. DC-SIGN Increases Japanese Encephalitis Virus Infection

    Directory of Open Access Journals (Sweden)

    Yang Yang, Ali Zohaib, Gong Chen, Jing Ye and Shengbo Cao*

    2013-11-01

    Full Text Available Japanese Encephalitis virus (JEV is a mosquito borne flavivirus that infects macrophages, monocytes and dendritic cells (DCs during in vivo replication. The C-type lectins DC-SIGN and DC-SIGNR have been reported to act as cell attachment factors for diverse array of pathogens. In this study, the effect of these lectins on JEV infection was investigated after the generation of 293T-SIGN (R cell lines expressing DC-SIGN and DC-SIGNR receptors. It was observed that only DC-SIGN but not the DC-SIGNR can act as a viral attachment factor in case of JEV infection. The infection to cells expressing DC-SIGN was efficiently blocked by anti-DC-SIGN and mannan molecules. It was also found that insect derived JEV has higher affinity for DC-SIGN as compare to the mammalian derived JEV. These results initially suggest that DC-SIGN could act as viral attachment receptors (VAR for JEV and enhance JEV infection.

  15. Respiratory Syncytial Virus Infections in Infants Affected by Primary Immunodeficiency

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    Marcello Lanari

    2014-01-01

    Full Text Available Primary immunodeficiencies are rare inherited disorders that may lead to frequent and often severe acute respiratory infections. Respiratory syncytial virus (RSV is one of the most frequent pathogens during early infancy and the infection is more severe in immunocompromised infants than in healthy infants, as a result of impaired T- and B-cell immune response unable to efficaciously neutralize viral replication, with subsequent increased viral shedding and potentially lethal lower respiratory tract infection. Several authors have reported a severe clinical course after RSV infections in infants and children with primary and acquired immunodeficiencies. Environmental prophylaxis is essential in order to reduce the infection during the epidemic season in hospitalized immunocompromised infants. Prophylaxis with palivizumab, a humanized monoclonal antibody against the RSV F protein, is currently recommended in high-risk infants born prematurely, with chronic lung disease or congenital heart disease. Currently however the prophylaxis is not routinely recommended in infants with primary immunodeficiency, although some authors propose the extension of prophylaxis to this high risk population.

  16. Experimental Infection of Cats and Dogs with West Nile Virus

    OpenAIRE

    Austgen, Laura E.; Bowen, Richard A.; Bunning, Michel L.; Davis, Brent S.; Mitchell, Carl J.; Chang, Gwong-Jen J.

    2004-01-01

    Domestic dogs and cats were infected by mosquito bite and evaluated as hosts for West Nile virus (WNV). Viremia of low magnitude and short duration developed in four dogs but they did not display signs of disease. Four cats became viremic, with peak titers ranging from 103.0 to 104.0 PFU/mL. Three of the cats showed mild, non-neurologic signs of disease. WNV was not isolated from saliva of either dogs or cats during the period of viremia. An additional group of four cats were exposed to WNV o...

  17. Novel inhibitors of human immunodeficiency virus type 2 infectivity

    OpenAIRE

    Beach, Lauren B.; Rawson, Jonathan M.; Kim, Baek; Patterson, Steven E.; Louis M. Mansky

    2014-01-01

    Human immunodeficiency virus type 2 (HIV-2) infects about two million people worldwide. HIV-2 has fewer treatment options than HIV-1, yet may evolve drug resistance more quickly. We have analysed several novel drugs for anti-HIV-2 activity. It was observed that 5-azacytidine, clofarabine, gemcitabine and resveratrol have potent anti-HIV-2 activity. The EC50 values for 5-azacytidine, clofarabine and resveratrol were found to be significantly lower with HIV-2 than with HIV-1. A time-of-addition...

  18. Seroprevalence 0f Dengue Virus Infection in Nepal

    OpenAIRE

    Gupta, B P; S.K. Mishra; K. D. Manandhar; R. Malla; C S Tamarakar; P P Raut; S.K. Sah; Pokhrel, S; R Rauniyar; A. Bajaracharya

    2013-01-01

    Dengue Virus infection is an emerging mosquito-borne disease. It is a global health problem and its expanding endemicity towards new territories is a serious concern. Relatively a new disease in Nepalese context, dengue abruptly appeared as massive outbreak in 2010, merely four years after its first introduction. It is a nagging public health problem in the low lands of Terai, expanding to new areas of Nepal in recent years. A cross-sectional study was conducted to determine anti-Dengue IgM ...

  19. Chronic hepatitis E virus infection in a patient with leukemia and elevated transaminases: a case report

    Directory of Open Access Journals (Sweden)

    Gauss Annika

    2012-10-01

    Full Text Available Abstract Introduction Acute hepatitis E virus infection may cause mild, self-limiting hepatitis, either as epidemic outbreaks or sporadic cases, the latter of which have been reported in industrialized countries. Chronic infections are uncommon and have been reported in immunosuppressed patients, patients with human immunodeficiency virus infection, and patients with hematological malignancies. Case presentation A 46-year-old Caucasian man was admitted to the gastroenterology clinic with a history of increasing transaminases, persistent exhaustion, and occasional right-side abdominal pain over the course of a 6-month period. B-cell chronic lymphocytic leukemia had been diagnosed several years earlier, and the patient was treated with rituximab, pentostatin, and cyclophosphamide. A diagnostic workup ruled out autoimmune and metabolic liver disease, hepatitis A-C, and herpes virus infection. A physical examination revealed enlarged axillary lymph nodes. The results of an abdominal ultrasound examination were otherwise unremarkable. Hepatitis E virus infection was diagnosed by detection of hepatitis E virus-specific antibodies. Blood samples were positive for hepatitis E virus ribonucleic acid with high viral loads for at least 8 months, demonstrating a rare chronic hepatitis E virus infection. Sequencing and phylogenetic analysis revealed hepatitis E virus genotype 3c with homologies to other European isolates from humans and swine, indicating an autochthonous infection. Conclusions Usually, hepatitis E virus infection appears as an acute infection; rare chronic infections have been reported for transplant patients, patients with human immunodeficiency virus, and patients with hematological malignancies. The chronic nature of hepatitis E infection in our patient was most likely induced by the immunosuppressive B-cell chronic lymphocytic leukemia treatment. The differential diagnosis in patients with unexplained hepatitis should include hepatitis E

  20. Dendritic cells in dengue virus infection: Targets of virus replication and mediators of immunity

    Directory of Open Access Journals (Sweden)

    Michael A. Schmid

    2014-12-01

    Full Text Available Dendritic cells (DCs are sentinels of the immune system and detect pathogens at sites of entry, such as the skin. In addition to the ability of DCs to control infections directly via their innate immune functions, DCs help to prime adaptive B and T cell responses via antigen presentation in lymphoid tissues. Infected Aedes aegypti or Ae. albopictus mosquitoes transmit the four dengue virus (DENV serotypes to humans while probing for small blood vessels in the skin. DENV causes the most prevalent arthropod-borne viral disease in humans, yet no vaccine or specific therapeutic is currently approved. Although primary DENV infection confers life-long protective immunity against re-infection with the same DENV serotype, secondary infection with a different DENV serotype can lead to increased disease severity via cross-reactive T cells or enhancing antibodies. This review summarizes recent findings in humans and animal models about DENV infection of DCs, monocytes and macrophages. We discuss the dual role of DCs as both targets of DENV replication and mediators of innate and adaptive immunity, and summarize immune evasion strategies whereby DENV impairs the function of infected DCs. We suggest that DCs play a key role in priming DENV-specific neutralizing or potentially harmful memory B and T cell responses, and that future DC-directed therapies may help induce protective memory responses and reduce dengue pathogenesis.