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Sample records for japanese encephalitis virus

  1. Japanese encephalitis virus in meningitis patients, Japan.

    PubMed

    Kuwayama, Masaru; Ito, Mikako; Takao, Shinichi; Shimazu, Yukie; Fukuda, Shinji; Miyazaki, Kazuo; Kurane, Ichiro; Takasaki, Tomohiko

    2005-03-01

    Cerebrospinal fluid specimens from 57 patients diagnosed with meningitis were tested for Japanese encephalitis virus. Total RNA was extracted from the specimens and amplified. Two products had highest homology with Nakayama strain and 2 with Ishikawa strain. Results suggest that Japanese encephalitis virus causes some aseptic meningitis in Japan. PMID:15757569

  2. Japanese encephalitis: the virus and vaccines.

    PubMed

    Yun, Sang-Im; Lee, Young-Min

    2014-01-01

    Japanese encephalitis (JE) is an infectious disease of the central nervous system caused by Japanese encephalitis virus (JEV), a zoonotic mosquito-borne flavivirus. JEV is prevalent in much of Asia and the Western Pacific, with over 4 billion people living at risk of infection. In the absence of antiviral intervention, vaccination is the only strategy to develop long-term sustainable protection against JEV infection. Over the past half-century, a mouse brain-derived inactivated vaccine has been used internationally for active immunization. To date, however, JEV is still a clinically important, emerging, and re-emerging human pathogen of global significance. In recent years, production of the mouse brain-derived vaccine has been discontinued, but 3 new cell culture-derived vaccines are available in various parts of the world. Here we review current aspects of JEV biology, summarize the 4 types of JEV vaccine, and discuss the potential of an infectious JEV cDNA technology for future vaccine development. PMID:24161909

  3. Japanese encephalitis.

    PubMed

    Morita, K; Nabeshima, T; Buerano, C C

    2015-08-01

    Japanese encephalitis (JE) is an inflammation of the central nervous system in humans and animals, specifically horses and cattle. The disease, which can sometimes be fatal, is caused by the flavivirus Japanese encephalitis virus (JEV), of which there are five genotypes (genotypes 1, 2, 3, 4 and 5). The transmission cycle of the virus involves pigs and wild birds as virus amplifiers and mosquitoes as vectors for transferring the virus between amplifying hosts and to dead- end hosts, i.e. humans, horses and cattle. In horses and cattle the disease is usually asymptomatic, but when clinical signs do occur they include fever, decreased appetite, frothing at the mouth, rigidity of the legs and recumbency, and neurological signs, such as convulsive fits, circling, marked depression and disordered consciousness. In pigs, it can cause abortion and stillbirths. At present, the virus is detected in a wide area covering eastern and southern Asia, Indonesia, northern Australia, Papua New Guinea and Pakistan. JEV RNA has also been detected in Italy, first in dead birds in 1997 and 2000 and then in mosquitoes in 2010. Genotype shift, i.e. a change of genotype from genotype 3 to genotype 1, has occurred in some countries, namely Japan, South Korea, Chinese Taipei and Vietnam. Laboratory methods are available for confirming the causative agent of the disease. There are control measures to prevent or minimise infection and, among them, vaccination is one of the most important and one which should be adopted in endemic and epidemic areas. PMID:26601447

  4. Antiviral activity of luteolin against Japanese encephalitis virus.

    PubMed

    Fan, Wenchun; Qian, Suhong; Qian, Ping; Li, Xiangmin

    2016-07-15

    Japanese encephalitis virus (JEV), a member of family Flaviviridae, is a neurotropic flavivirus that causes Japanese encephalitis (JE). JEV is one of the most important causative agents of viral encephalitis in humans, and this disease leads to high fatality rates. Although effective vaccines are available, no effective antiviral therapy for JE has been developed. Hence, identifying effective antiviral agents against JEV infection is important. In this study, we found that luteolin was an antiviral bioflavonoid with potent antiviral activity against JEV replication in A549 cells with IC50=4.56μg/mL. Luteolin also showed extracellular virucidal activity on JEV. With a time-of-drug addition assay revealing that JEV replication was inhibited by luteolin after the entry stage. Overall, our results suggested that luteolin can be used to develop an antiviral drug against JEV. PMID:27126774

  5. Japanese encephalitis

    PubMed Central

    Yun, Sang-Im; Lee, Young-Min

    2014-01-01

    Japanese encephalitis (JE) is an infectious disease of the central nervous system caused by Japanese encephalitis virus (JEV), a zoonotic mosquito-borne flavivirus. JEV is prevalent in much of Asia and the Western Pacific, with over 4 billion people living at risk of infection. In the absence of antiviral intervention, vaccination is the only strategy to develop long-term sustainable protection against JEV infection. Over the past half-century, a mouse brain-derived inactivated vaccine has been used internationally for active immunization. To date, however, JEV is still a clinically important, emerging, and re-emerging human pathogen of global significance. In recent years, production of the mouse brain-derived vaccine has been discontinued, but 3 new cell culture-derived vaccines are available in various parts of the world. Here we review current aspects of JEV biology, summarize the 4 types of JEV vaccine, and discuss the potential of an infectious JEV cDNA technology for future vaccine development. PMID:24161909

  6. Origin and evolution of Japanese encephalitis virus in southeast Asia.

    PubMed

    Solomon, Tom; Ni, Haolin; Beasley, David W C; Ekkelenkamp, Miquel; Cardosa, Mary Jane; Barrett, Alan D T

    2003-03-01

    Since it emerged in Japan in the 1870s, Japanese encephalitis has spread across Asia and has become the most important cause of epidemic encephalitis worldwide. Four genotypes of Japanese encephalitis virus (JEV) are presently recognized (representatives of genotypes I to III have been fully sequenced), but its origin is not known. We have determined the complete nucleotide and amino acid sequence of a genotype IV Indonesian isolate (JKT6468) which represents the oldest lineage, compared it with other fully sequenced genomes, and examined the geographical distribution of all known isolates. JKT6468 was the least similar, with nucleotide divergence ranging from 17.4 to 19.6% and amino acid divergence ranging from 4.7 to 6.5%. It included an unusual series of amino acids at the carboxy terminus of the core protein unlike that seen in other JEV strains. Three signature amino acids in the envelope protein (including E327 Leu-->Thr/Ser on the exposed lateral surface of the putative receptor binding domain) distinguished genotype IV strains from more recent genotypes. Analysis of all 290 JEV isolates for which sequence data are available showed that the Indonesia-Malaysia region has all genotypes of JEV circulating, whereas only more recent genotypes circulate in other areas (P < 0.0001). These results suggest that JEV originated from its ancestral virus in the Indonesia-Malaysia region and evolved there into the different genotypes which then spread across Asia. Our data, together with recent evidence on the origins of other emerging viruses, including dengue virus and Nipah virus, imply that tropical southeast Asia may be an important zone for emerging pathogens. PMID:12584335

  7. Japanese encephalitis virus tropism in experimentally infected pigs.

    PubMed

    Ricklin, Meret E; Garcìa-Nicolàs, Obdulio; Brechbühl, Daniel; Python, Sylvie; Zumkehr, Beatrice; Posthaus, Horst; Oevermann, Anna; Summerfield, Artur

    2016-01-01

    Pigs are considered to be the main amplifying host for Japanese encephalitis virus (JEV), and their infection can correlate with human cases of disease. Despite their importance in the ecology of the virus as it relates to human cases of encephalitis, the pathogenesis of JEV in pigs remains obscure. In the present study, the localization and kinetics of virus replication were investigated in various tissues after experimental intravenous infection of pigs. The data demonstrate a rapid and broad spreading of the virus to the central nervous system (CNS) and various other organs. A particular tropism of JEV in pigs not only to the CNS but also for secondary lymphoid tissue, in particular the tonsils with the overall highest viral loads, was observed. In this organ, even 11 days post infection, the latest time point of the experiment, no apparent decrease in viral RNA loads and live virus was found despite the presence of a neutralizing antibody response. This was also well beyond the clinical and viremic phase. These results are of significance for the pathogenesis of JEV, and call for further experimental studies focusing on the cellular source and duration of virus replication in pigs. PMID:26911997

  8. Recombinant chimeric Japanese encephalitis virus/tick-borne encephalitis virus is attenuated and protective in mice.

    PubMed

    Wang, Hong-Jiang; Li, Xiao-Feng; Ye, Qing; Li, Shi-Hua; Deng, Yong-Qiang; Zhao, Hui; Xu, Yan-Peng; Ma, Jie; Qin, E-De; Qin, Cheng-Feng

    2014-02-12

    Tick-borne encephalitis virus (TBEV) represents one of the most dangerous human pathogens circulating in Europe and East Asia. No effective treatment for TBEV infection currently exists, and vaccination is the primary preventive measure. Although several inactivated vaccines have been licensed, the development of novel vaccines against TBEV remains a high priority in disease-endemic countries. In the present study, a live chimeric recombinant TBEV (ChinTBEV) was created by substituting the major structural genes of TBEV for the corresponding regions of Japanese encephalitis virus (JEV) live vaccine strain SA14-14-2. The resulting chimera had a small-plaque phenotype, replicated efficiently in both mammalian and mosquito cells. The preliminary data from in vitro passaging indicated the potential for stability of ChinTBEV. ChinTBEV also exhibited significantly attenuated neuroinvasiveness in mice upon either intraperitoneal or subcutaneous inoculation in comparison with its parental TBEV. Importantly, a single immunisation with ChinTBEV elicited TBEV-specific IgG and neutralising antibody responses in a dose-dependent manner, providing significant protection against lethal TBEV challenge in mice. Taken together, the results of this proof-of-concept study indicate that ChinTBEV can be further developed as a potential vaccine candidate against TBEV infection. Moreover, the construction of this type of flavivirus chimera using a JEV vaccine strain as the genetic backbone represents a universal vaccine approach. PMID:24394443

  9. Virion and soluble antigens of japanese encephalitis virus.

    PubMed Central

    Eckels, K H; Hetrick, F M; Russell, P K

    1975-01-01

    Japanese encephalitis virions contain a 58 X 10-3-molecular-weight envelope glycoprotein antigen that can be solubilized with sodium lauryl sulfate and separated from other virion structural polypeptides and viral ribonucleic acid by gel filtration chromatography. The 58 X 10-3-molecular-weight envelope protein is the major antigen responsible for cross-reactivity of the virion in complement fixation tests with other closely related arboviruses. A naturally occurring soluble complement-fixing antigen is found in Japanese encephalitis mouse brain preparations after removal of particulate antigens. After partial purification by gel filtration and isoelectric focusing, the 53 X 10-3-molecular weight soluble complement-fixing antigen is more type specific than the Japanese encephalitis envelope antigen in complement fixation tests. Further, the Japanese encephalitis soluble complement-fixing antigen is stable to treatment with sodium lauryl sulfate and 2-mercaptoethanol, whereas virion complement-fixing antigens are unstable after this treatment. Images PMID:47312

  10. Phylogeography of Japanese Encephalitis Virus: Genotype Is Associated with Climate

    PubMed Central

    Schuh, Amy J.; Ward, Melissa J.; Leigh Brown, Andrew J.; Barrett, Alan D. T.

    2013-01-01

    The circulation of vector-borne zoonotic viruses is largely determined by the overlap in the geographical distributions of virus-competent vectors and reservoir hosts. What is less clear are the factors influencing the distribution of virus-specific lineages. Japanese encephalitis virus (JEV) is the most important etiologic agent of epidemic encephalitis worldwide, and is primarily maintained between vertebrate reservoir hosts (avian and swine) and culicine mosquitoes. There are five genotypes of JEV: GI-V. In recent years, GI has displaced GIII as the dominant JEV genotype and GV has re-emerged after almost 60 years of undetected virus circulation. JEV is found throughout most of Asia, extending from maritime Siberia in the north to Australia in the south, and as far as Pakistan to the west and Saipan to the east. Transmission of JEV in temperate zones is epidemic with the majority of cases occurring in summer months, while transmission in tropical zones is endemic and occurs year-round at lower rates. To test the hypothesis that viruses circulating in these two geographical zones are genetically distinct, we applied Bayesian phylogeographic, categorical data analysis and phylogeny-trait association test techniques to the largest JEV dataset compiled to date, representing the envelope (E) gene of 487 isolates collected from 12 countries over 75 years. We demonstrated that GIII and the recently emerged GI-b are temperate genotypes likely maintained year-round in northern latitudes, while GI-a and GII are tropical genotypes likely maintained primarily through mosquito-avian and mosquito-swine transmission cycles. This study represents a new paradigm directly linking viral molecular evolution and climate. PMID:24009790

  11. Crystal Structure of the Japanese Encephalitis Virus Envelope Protein

    SciTech Connect

    Luca, Vincent C.; AbiMansour, Jad; Nelson, Christopher A.; Fremont, Daved H.

    2012-03-13

    Japanese encephalitis virus (JEV) is the leading global cause of viral encephalitis. The JEV envelope protein (E) facilitates cellular attachment and membrane fusion and is the primary target of neutralizing antibodies. We have determined the 2.1-{angstrom} resolution crystal structure of the JEV E ectodomain refolded from bacterial inclusion bodies. The E protein possesses the three domains characteristic of flavivirus envelopes and epitope mapping of neutralizing antibodies onto the structure reveals determinants that correspond to the domain I lateral ridge, fusion loop, domain III lateral ridge, and domain I-II hinge. While monomeric in solution, JEV E assembles as an antiparallel dimer in the crystal lattice organized in a highly similar fashion as seen in cryo-electron microscopy models of mature flavivirus virions. The dimer interface, however, is remarkably small and lacks many of the domain II contacts observed in other flavivirus E homodimers. In addition, uniquely conserved histidines within the JEV serocomplex suggest that pH-mediated structural transitions may be aided by lateral interactions outside the dimer interface in the icosahedral virion. Our results suggest that variation in dimer structure and stability may significantly influence the assembly, receptor interaction, and uncoating of virions.

  12. Seroprevalence of Japanese encephalitis virus infection in captive Japanese macaques (Macaca fuscata).

    PubMed

    Shimoda, Hiroshi; Saito, Akatsuki; Noguchi, Keita; Terada, Yutaka; Kuwata, Ryusei; Akari, Hirofumi; Takasaki, Tomohiko; Maeda, Ken

    2014-07-01

    Japanese encephalitis virus (JEV), which is transmitted by mosquitoes, infects many animal species and causes serious acute encephalitis in humans and horses. In this study, a serosurvey of JEV in Japanese macaques (Macaca fuscata) reared in Aichi Prefecture was conducted using purified JEV as an antigen for ELISA. The results revealed that 146 of 332 monkeys (44 %) were seropositive for JEV. In addition, 35 of 131 monkeys (27 %) born in the facility were seropositive, and the annual infection rate in the facility was estimated as 13 %. Our results provide evidence of the frequent exposure of many Japanese macaques to JEV, suggesting that there is a risk of JEV transmission to humans by mosquitoes. PMID:24748049

  13. Emergence or improved detection of Japanese encephalitis virus in the Himalayan highlands?

    PubMed Central

    Baylis, Matthew; Barker, Christopher M.; Caminade, Cyril; Joshi, Bhoj R.; Pant, Ganesh R.; Rayamajhi, Ajit; Reisen, William K.; Impoinvil, Daniel E.

    2016-01-01

    The emergence of Japanese encephalitis virus (JEV) in the Himalayan highlands is of significant veterinary and public health concern and may be related to climate warming and anthropogenic landscape change, or simply improved surveillance. To investigate this phenomenon, a One Health approach focusing on the phylogeography of JEV, the distribution and abundance of the mosquito vectors, and seroprevalence in humans and animal reservoirs would be useful to understand the epidemiology of Japanese encephalitis in highland areas. PMID:26956778

  14. Emergence or improved detection of Japanese encephalitis virus in the Himalayan highlands?

    PubMed

    Baylis, Matthew; Barker, Christopher M; Caminade, Cyril; Joshi, Bhoj R; Pant, Ganesh R; Rayamajhi, Ajit; Reisen, William K; Impoinvil, Daniel E

    2016-04-01

    The emergence of Japanese encephalitis virus (JEV) in the Himalayan highlands is of significant veterinary and public health concern and may be related to climate warming and anthropogenic landscape change, or simply improved surveillance. To investigate this phenomenon, a One Health approach focusing on the phylogeography of JEV, the distribution and abundance of the mosquito vectors, and seroprevalence in humans and animal reservoirs would be useful to understand the epidemiology of Japanese encephalitis in highland areas. PMID:26956778

  15. Antioxidants: potential antiviral agents for Japanese encephalitis virus infection.

    PubMed

    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

  16. Antibodies to H5 subtype avian influenza virus and Japanese encephalitis virus in northern pintails (Anas acuta) sampled in Japan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blood samples from 105 northern pintails (Anas acuta) captured on Hokkaido, Japan were tested for antibodies to avian influenza virus (AIV), Japanese encephalitis virus (JEV) and West Nile virus (WNV) to assess possible involvement of this species in the transmission and spread of economically impor...

  17. Susceptibility of a North American Culex quinquefasciatus to Japanese encephalitis virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Japanese encephalitis virus (JEV) is a flavivirus that is transmitted by Culex (Cx.) tritaeniorhynchus in tropical and subtropical regions of Asia. The endemic transmission cycle involves domestic pigs and avian species that serve as amplification hosts; humans are incidental hosts that cannot devel...

  18. Neutralization of Japanese Encephalitis Virus by heme-induced broadly reactive human monoclonal antibody

    PubMed Central

    Gupta, Nimesh; de Wispelaere, Mélissanne; Lecerf, Maxime; Kalia, Manjula; Scheel, Tobias; Vrati, Sudhanshu; Berek, Claudia; Kaveri, Srinivas V.; Desprès, Philippe; Lacroix-Desmazes, Sébastien; Dimitrov, Jordan D.

    2015-01-01

    Geographical expansion and re-emerging new genotypes of the Japanese encephalitis virus (JEV) require the development of novel therapeutic approaches. Here, we studied a non-conventional approach for antibody therapy and show that, upon exposure to heme, a fraction of natural human immunoglobulins acquires high-affinity reactivity with the antigenic domain-III of JEV E glycoprotein. These JEV-reactive antibodies exhibited neutralizing activity against recently dominant JEV genotypes. This study opens new therapeutic options for Japanese encephalitis. PMID:26542535

  19. A systematic review of the literature to identify and quantify host and vector competence and abundance of Japanese Encephalitis Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Japanese Encephalitis virus (JEV) is a mosquito-borne arbovirus that causes endemic and epidemic encephalitis in Eastern and Southeastern Asia. Swine and wading birds serve as reservoirs for the virus, which can be transmitted to humans via mosquitos. Currently, there is no specific treatment availa...

  20. Japanese encephalitis virus vaccine candidates generated by chimerization with dengue virus type 4.

    PubMed

    Gromowski, Gregory D; Firestone, Cai-Yen; Hanson, Christopher T; Whitehead, Stephen S

    2014-05-23

    Japanese encephalitis virus (JEV) is a leading cause of viral encephalitis worldwide and vaccination is one of the most effective ways to prevent disease. A suitable live-attenuated JEV vaccine could be formulated with a live-attenuated tetravalent dengue vaccine for the control of these viruses in endemic areas. Toward this goal, we generated chimeric virus vaccine candidates by replacing the precursor membrane (prM) and envelope (E) protein structural genes of recombinant dengue virus type 4 (rDEN4) or attenuated vaccine candidate rDEN4Δ30 with those of wild-type JEV strain India/78. Mutations were engineered in E, NS3 and NS4B protein genes to improve replication in Vero cells. The chimeric viruses were attenuated in mice and some elicited modest but protective levels of immunity after a single dose. One particular chimeric virus, bearing E protein mutation Q264H, replicated to higher titer in tissue culture and was significantly more immunogenic in mice. The results are compared with live-attenuated JEV vaccine strain SA14-14-2. PMID:24699473

  1. Studies on Japanese B Encephalitis Virus Vaccines from Tissue Culture

    PubMed Central

    Singh, Balwant; Hammon, W. McD.

    1971-01-01

    A study was carried out to evaluate the reliability of and to determine the mechanism involved in an antigen extinction mouse intraperitoneal (ip) challenge test for potency of a cell culture vaccine for Japanese B encephalitis, a modification of a test originated by Sabin for a mouse brain vaccine. Some comparisons were made with the official Japanese test using an intracerebral (ic) challenge after a more prolonged immunization procedure. The Japanese method of using a lyophilized reference vaccine with each test was also employed. It was found that the ip and the ic test appeared to show similar relative differences between lots. The ip test was more quickly and readily performed, gave reasonably consistent results on repetition, and, when used with a suitable reference vaccine, gave promise of being an entirely suitable and reliable test. Immunization by the intramuscular route rather than by the regular ip route appeared to offer no advantage and was less consistent in responses shown. Neutralizing antibody responses of the mice in the standard procedure were very quick to appear, about 4 days after the first dose of vaccine and had a peak titer about the seventh day, the time of challenge. This titer fell quickly unless challenge occurred. The antibody was heat stable, but it was readily inactivated by 2-mercaptoethanol (2-ME). Not until the 11th or 15th day did a small amount of immunoglobulin G appear. Challenge on day 7 significantly increased titers, but this antibody was also mostly inactivated by 2-ME. Interferon did not appear to play any significant role in the protection shown by the mice. PMID:4325023

  2. Low Protective Efficacy of the Current Japanese Encephalitis Vaccine against the Emerging Genotype 5 Japanese Encephalitis Virus

    PubMed Central

    Gao, Xiaoyan; Li, Minghua; Cui, Shiheng; Li, Xiaolong; Cao, Yuxi; Lei, Wenwen; Lu, Zhi; He, Ying; Wang, Huanyu; Yan, Jinghua; Gao, George Fu; Liang, Guodong

    2016-01-01

    Background The current Japanese encephalitis (JE) vaccine derived from G3 JE virus (JEV) can induce protective immunity against G1–G4 JEV genotypes. However, protective efficacy against the emerging G5 genotype has not been reported. Methods/Principal Findings Using in vitro and in vivo tests, biological phenotype and cross-immunoreactions were compared between G3 JEV and G5 JEV (wild strains). The PRNT90 method was used to detect neutralizing antibodies against different genotypes of JEV in JE vaccine-immunized subjects and JE patients. In JE vaccine-immunized mice, the lethal challenge protection rates against G3 and G5 JEV wild strains were 100% and 50%, respectively. The seroconversion rates (SCRs) of virus antibodies against G3 and G5 JEV among vaccinated healthy subjects were 100% and 35%, respectively. All clinically identified JE patients showed high levels of G3 JEV neutralizing antibodies (≥1:10–1280) with positive serum geometric mean titers (GMTs) of 43.2, while for G5 JEV, neutralizing antibody conversion rates were only 64% with positive serum GMTs of 11.14. Moreover, the positive rate of JEV neutralizing antibodies against G5 JEV in pediatric patients was lower than in adults. Conclusions/Significance Low levels of neutralizing/protective antibodies induced by the current JE vaccine, based on the G3 genotype, were observed against the emerging G5 JEV genotype. Our results demonstrate the need for more detailed studies to reevaluate whether or not the apparent emergence of G5 JEV can be attributed to failure of the current vaccine to induce appropriate immune protectivity against this genotype of JEV. PMID:27139722

  3. Monoclonal immunoglobulin M antibody to Japanese encephalitis virus that can react with a nuclear antigen in mammalian cells.

    PubMed Central

    Gould, E A; Chanas, A C; Buckley, A; Clegg, C S

    1983-01-01

    An immunoglobulin M (IgM) class monoclonal antibody raised against Japanese encephalitis virus reacted with an epitope on the nonstructural virus protein P74 (NV4 in the old nomenclature) of several flaviviruses and also with an antigen present in the nuclei of a variety of mammalian cell types. This antigen had a characteristic granular distribution by immunofluorescence and may correspond to a polypeptide of molecular weight 56,000 seen in nitrocellulose transfers of sodium dodecyl sulfate-polyacrylamide gels. Cross-reactivity with nuclear antigen was also occasionally observed in the IgM antibody fraction of mice early after infection with Japanese encephalitis virus and also in acute sera from some clinical cases of encephalitis containing IgM antibody to Japanese encephalitis virus. Images PMID:6135665

  4. Japanese viral encephalitis

    PubMed Central

    Tiroumourougane, S; Raghava, P; Srinivasan, S

    2002-01-01

    One of the leading causes of acute encephalopathy in children in the tropics is Japanese encephalitis (JE). Transmitted by the culex mosquito, this neurotropic virus predominately affects the thalamus, anterior horns of the spinal cord, cerebral cortex, and cerebellum. It mainly affects children <15 years and is mostly asymptomatic. The occasional symptomatic child typically presents with a neurological syndrome characterised by altered sensorium, seizures, and features of intracranial hypertension. Aetiological diagnosis is based on virus isolation or demonstration of virus specific antigen or antibodies in the cerebrospinal fluid/blood. Though no antiviral drug is available against JE, effective supportive management can improve the outcome. Control of JE involves efficient vector control and appropriate use of vaccines. PMID:11930023

  5. Estimating the Burden of Japanese Encephalitis Virus and Other Encephalitides in Countries of the Mekong Region

    PubMed Central

    Tarantola, Arnaud; Goutard, Flavie; Newton, Paul; de Lamballerie, Xavier; Lortholary, Olivier; Cappelle, Julien; Buchy, Philippe

    2014-01-01

    Diverse aetiologies of viral and bacterial encephalitis are widely recognized as significant yet neglected public health issues in the Mekong region. A robust analysis of the corresponding health burden is lacking. We retrieved 75 articles on encephalitis in the region published in English or in French from 1965 through 2011. Review of available data demonstrated that they are sparse and often derived from hospital-based studies with significant recruitment bias. Almost half (35 of 75) of articles were on Japanese encephalitis virus (JEV) alone or associated with dengue. In the Western Pacific region the WHO reported 30,000–50,000 annual JEV cases (15,000 deaths) between 1966 and 1996 and 4,633 cases (200 deaths) in 2008, a decline likely related to the introduction of JEV vaccination in China, Vietnam, or Thailand since the 1980s. Data on dengue, scrub typhus and rabies encephalitis, among other aetiologies, are also reviewed and discussed. Countries of the Mekong region are undergoing profound demographic, economic and ecological change. As the epidemiological aspects of Japanese encephalitis (JE) are transformed by vaccination in some countries, highly integrated expert collaborative research and objective data are needed to identify and prioritize the human health, animal health and economic burden due to JE and other pathogens associated with encephalitides. PMID:24498443

  6. Japanese Encephalitis Vaccines

    PubMed Central

    McArthur, Monica A.; Holbrook, Michael R.

    2012-01-01

    Japanese encephalitis (JE) is a significant human health concern in Asia, Indonesia and parts of Australia with more than 3 billion people potentially at risk of infection with Japanese encephalitis virus (JEV), the causative agent of JE. Given the risk to human health and the theoretical potential for JEV use as a bioweapon, the development of safe and effective vaccines to prevent JEV infection is vital for preserving human health. The development of vaccines for JE began in the 1940s with formalin-inactivated mouse brain-derived vaccines. These vaccines have been shown to induce a protective immune response and to be very effective. Mouse brain-derived vaccines were still in use until May 2011 when the last lots of the BIKEN® JE-VAX® expired. Development of modern JE vaccines utilizes cell culture-derived viruses and improvements in manufacturing processes as well as removal of potential allergens or toxins have significantly improved vaccine safety. China has developed a live-attenuated vaccine that has proven to induce protective immunity following a single inoculation. In addition, a chimeric vaccine virus incorporating the prM and E structural proteins derived from the live-attenuated JE vaccine into the live-attenuated yellow fever 17D vaccine virus backbone is currently in clinical trials. In this article, we provide a summary of JE vaccine development and on-going clinical trials. We also discuss the potential risk of JEV as a bioweapon with a focus on virus sustainability if used as a weapon. PMID:23125946

  7. Vector-free transmission and persistence of Japanese encephalitis virus in pigs

    PubMed Central

    Ricklin, Meret E.; García-Nicolás, Obdulio; Brechbühl, Daniel; Python, Sylvie; Zumkehr, Beatrice; Nougairede, Antoine; Charrel, Remi N.; Posthaus, Horst; Oevermann, Anna; Summerfield, Artur

    2016-01-01

    Japanese encephalitis virus (JEV), a main cause of severe viral encephalitis in humans, has a complex ecology, composed of a cycle involving primarily waterbirds and mosquitoes, as well as a cycle involving pigs as amplifying hosts. To date, JEV transmission has been exclusively described as being mosquito-mediated. Here we demonstrate that JEV can be transmitted between pigs in the absence of arthropod vectors. Pigs shed virus in oronasal secretions and are highly susceptible to oronasal infection. Clinical symptoms, virus tropism and central nervous system histological lesions are similar in pigs infected through needle, contact or oronasal inoculation. In all cases, a particularly important site of replication are the tonsils, in which JEV is found to persist for at least 25 days despite the presence of high levels of neutralizing antibodies. Our findings could have a major impact on the ecology of JEV in temperate regions with short mosquito seasons. PMID:26902924

  8. Vector-free transmission and persistence of Japanese encephalitis virus in pigs.

    PubMed

    Ricklin, Meret E; García-Nicolás, Obdulio; Brechbühl, Daniel; Python, Sylvie; Zumkehr, Beatrice; Nougairede, Antoine; Charrel, Remi N; Posthaus, Horst; Oevermann, Anna; Summerfield, Artur

    2016-01-01

    Japanese encephalitis virus (JEV), a main cause of severe viral encephalitis in humans, has a complex ecology, composed of a cycle involving primarily waterbirds and mosquitoes, as well as a cycle involving pigs as amplifying hosts. To date, JEV transmission has been exclusively described as being mosquito-mediated. Here we demonstrate that JEV can be transmitted between pigs in the absence of arthropod vectors. Pigs shed virus in oronasal secretions and are highly susceptible to oronasal infection. Clinical symptoms, virus tropism and central nervous system histological lesions are similar in pigs infected through needle, contact or oronasal inoculation. In all cases, a particularly important site of replication are the tonsils, in which JEV is found to persist for at least 25 days despite the presence of high levels of neutralizing antibodies. Our findings could have a major impact on the ecology of JEV in temperate regions with short mosquito seasons. PMID:26902924

  9. Voltage dependent anion channel is redistributed during Japanese encephalitis virus infection of insect cells.

    PubMed

    Fongsaran, Chanida; Phaonakrop, Narumon; Roytrakul, Sittiruk; Thepparit, Chutima; Kuadkitkan, Atichat; Smith, Duncan R

    2014-01-01

    Despite the availability of an effective vaccine, Japanese encephalitis remains a significant cause of morbidity and mortality in many parts of Asia. Japanese encephalitis is caused by the Japanese encephalitis virus (JEV), a mosquito transmitted flavivirus. Many of the details of the virus replication cycle in mosquito cells remain unknown. This study sought to determine whether GRP78, a well-characterized flavivirus E protein interacting protein, interacted with JEV E protein in insect cells, and whether this interaction was mediated at the cell surface. GRP78 was shown to interact with JEV E protein by coimmunoprecipitation, and was additionally shown to interact with voltage dependent anion protein (VDAC) through the same methodology. Antibody inhibition experiments showed that neither GRP78 nor VDAC played a role in JEV internalization to insect cells. Interestingly, VDAC was shown to be significantly relocalized in response to JEV infection, and significant levels of colocalization between VDAC and GRP78 and VDAC and ribosomal L28 protein were seen in JEV infected but not uninfected cells. This is the first report of relocalization of VDAC in response to JEV infection and suggests that this may be a part of the JEV replication strategy in insect cells. PMID:25126612

  10. Japanese encephalitis virus infects neural progenitor cells and decreases their proliferation.

    PubMed

    Das, Sulagna; Basu, Anirban

    2008-08-01

    Japanese encephalitis virus (JEV), a common cause of encephalitis in humans, especially in children, leads to substantial neuronal injury. The survivors of JEV infection have severe cognitive impairment, motor and behavioral disorders. We hypothesize that depletion of neural progenitor cells (NPCs) by the virus culminates in neurological sequelae in survivors of Japanese encephalitis (JE). We utilized both in vivo model of JEV infection and in vitro neurosphere cultures to study progressive JEV infection. Cellular infection and cell death was determined by flow cytometry. BrdU administration in animals and in neurospheres was used to determine the proliferative ability of NPCs. JEV leads to massive loss of actively proliferating NPC population from the subventricular zone (SVZ). The ability of JEV infected subventricular zone cells to form neurospheres is severely compromised. This can be attributed to JEV infection in NPCs, which however do not result in robust death of the resilient NPC cells. Instead, JEV suppresses the cycling ability of these cells, preventing their proliferation. JEV primarily targets at a critical postnatal age and severely diminishes the NPC pool in SVZ, thus impairing the process of recovery after the insult. This arrested growth and proliferation of NPCs might have an effect on the neurological consequences in JE survivors. PMID:18540995

  11. Japanese Encephalitis: Frequently Asked Questions

    MedlinePlus

    ... of Page How long does the Japanese encephalitis vaccination last? The duration of protection is unknown. For ... What are the side effects of Japanese encephalitis vaccination? Pain and tenderness are the most commonly reported ...

  12. Bagaza virus inhibits Japanese encephalitis & West Nile virus replication in Culex tritaeniorhynchus & Cx. quinquefasciatus mosquitoes

    PubMed Central

    Sudeep, A.B.; Bondre, V.P.; George, R.; Ghodke, Y.S.; Aher, R.V.; Gokhale, M.D.

    2015-01-01

    Background & objectives: Studies have shown that certain flaviviruses influence susceptibility of mosquitoes by inhibiting/enhancing replication of important flaviviruses. Hence, a study was designed to determine whether Bagaza virus (BAGV), a flavivirus isolated from Culex tritaeniorhynchus mosquitoes in India, alters susceptibility of Cx. tritaeniorhynchus and Cx. quinquefasciatus mosquitoes to Japanese encephalitis (JEV) and West Nile viruses (WNV). Methods: JEV and WNV infection in Cx. tritaeniorhynchus and Cx. quinquefasciatus mosquitoes in the presence of BAGV was carried out by intrathoracic (IT) inoculation and oral feeding methods. Mosquitoes were infected with BAGV and WNV/JEV either simultaneously or in a phased manner, in which mosquitoes were infected with BAGV by IT inoculation followed by super-infection with JEV/WNV after eight days post-infection (PI). JEV and WNV yield on 7th and 14th day PI after super-infection was determined by 50 per cent tissue culture infective dose (TCID50) method. Results: In Cx. tritaeniorhynchus mosquitoes, prior infection with BAGV significantly reduced JEV and WNV replication while in Cx. quinquefasciatus, BAGV influence was only seen with WNV. Reduction in virus titre was observed in IT inoculated and oral fed mosquitoes irrespective of the infection mode. JEV replication was also found reduced in Cx. tritaeniorhynchus mosquitoes persistently infected with BAGV at passage four. Interpretation & conclusions: BAGV infection in Cx. tritaeniorhynchus and Cx. quinquefasciatus mosquitoes altered their susceptibility to JEV and WNV producing low virus yield. However, the role of BAGV in inhibiting JEV/WNV replication in field mosquitoes needs further investigations. PMID:26905241

  13. Involvement of the Host Cell Nuclear Envelope Membranes in the Replication of Japanese Encephalitis Virus

    PubMed Central

    Zebovitz, E.; Leong, J. K. L.; Doughty, S. C.

    1974-01-01

    The distribution of viral ribonucleic acid (RNA) on various cell membrane fractions derived from a porcine kidney cell line infected with Japanese encephalitis virus was investigated. At 40 h postinfection, after virus growth had reached its peak, three viral RNAs, 45S, 27S, and 20S, were associated with the cytoplasmic membranes and intact nuclei. The amount of each RNA associated with the nucleus was two- to fivefold greater than that present with the cytoplasmic membranes. Treatment of washed infected nuclei with 1.0% Triton X-100, which removed the outer nuclear envelope membrane, also removed the viral RNA. When the nucleus was fractionated into nuclear envelope membranes and a large particle fraction which sedimented at 600 × g, nearly all of the viral RNA remained associated with the envelope membranes. The nuclear envelope membranes contained higher viral RNA polymerase activity than the cytoplasmic membranes derived from the same cells. These data suggest that major sites for Japanese encephalitis virus RNA synthesis may be localized on or in very close association with the nuclear envelope membranes. PMID:4842128

  14. Enhanced immune responses against Japanese encephalitis virus using recombinant adenoviruses coexpressing Japanese encephalitis virus envelope and porcine interleukin-6 proteins in mice.

    PubMed

    Liu, Hanyang; Wu, Rui; Liu, Kai; Yuan, Lei; Huang, Xiaobo; Wen, Yiping; Ma, Xiaoping; Yan, Qigui; Zhao, Qin; Wen, Xintian; Cao, Sanjie

    2016-08-15

    Japanese encephalitis is a reproductive disorder caused by Japanese encephalitis virus (JEV) in swine. Previous studies have demonstrated that recombinant adenovirus serotype 5 (Ad5) may be a potential vaccine candidate because it can express JEV envelope epitopes and induce immune responses against JEV. Still, it will be necessary to develop an adjuvant that can enhance both humoral and cellular immune responses to the recombinant antigen delivered by non-replicating Ad5. In this study, we investigated the systemic immune responses of BALB/c mice immunized with recombinant adenovirus expressing JEV envelope epitopes in combination with porcine interleukin-6 (rAdE-IL-6).The rAdE-IL-6 immunized group had the highest titers of anti-JEV antibody as detected by an enzyme-linked immunosorbent assay (ELISA), as well as the highest levels of neutralizing antibody (1:75) as detected by a serum neutralization test. Similarly, higher concentrations of interferon-gamma (834.7pg/ml) and interleukin-6 (IL-6) (229.7pg/ml) were detected in the rAdE-IL-6 group using an ELISA assay. These data indicate that immunized BALB/c induce a strong cellular response against rAdE-IL-6. Furthermore, after challenge with the virulent JEV SCYA201201 strain, the rAdE-IL-6 group generated an immune protective response 70% greater than that of the control group, indicating that rAdE-IL-6 induced a protective immune response against JEV challenge in mice. The results from this study demonstrated that IL-6 is a strong adjuvant that can enhance both humoral and cellular immune responses in mice. Furthermore, a recombinant adenovirus coexpressing JEV envelope epitopes and porcine IL-6 protein may be an effective vaccine in animals. PMID:27235810

  15. Safety and immunogenicity of a live attenuated Japanese encephalitis chimeric virus vaccine (IMOJEV®) in children.

    PubMed

    Chokephaibulkit, K; Houillon, G; Feroldi, E; Bouckenooghe, A

    2016-01-01

    JE-CV (IMOJEV®, Sanofi Pasteur, France) is a live attenuated virus vaccine constructed by inserting coding sequences of the prM and E structural proteins of the Japanese encephalitis SA14-14-2 virus into the genome of yellow fever 17D virus. Primary immunization with JE-CV requires a single dose of the vaccine. This article reviews clinical trials of JE-CV in children aged up to 6 years conducted in countries across South-East Asia. Strong and persistent antibody responses were observed after single primary and booster doses, with 97% of children seroprotected up to five years after booster vaccination. Models of long-term antibody persistence predict a median duration of protection of approximately 30 years after a booster dose. The safety and reactogenicity profiles of JE-CV primary and booster doses are comparable to other widely used childhood vaccines. PMID:26588242

  16. Molecular epidemiology of Japanese encephalitis virus in mosquitoes in Taiwan during 2005-2012.

    PubMed

    Su, Chien-Ling; Yang, Cheng-Fen; Teng, Hwa-Jen; Lu, Liang-Chen; Lin, Cheo; Tsai, Kun-Hsien; Chen, Yu-Yu; Chen, Li-Yu; Chang, Shu-Fen; Shu, Pei-Yun

    2014-10-01

    Japanese encephalitis (JE) is a mosquito-borne zoonotic disease caused by the Japanese encephalitis virus (JEV). Pigs and water birds are the main amplifying and maintenance hosts of the virus. In this study, we conducted a JEV survey in mosquitoes captured in pig farms and water bird wetland habitats in Taiwan during 2005 to 2012. A total of 102,633 mosquitoes were collected. Culex tritaeniorhynchus was the most common mosquito species found in the pig farms and wetlands. Among the 26 mosquito species collected, 11 tested positive for JEV by RT-PCR, including Cx. tritaeniorhynchus, Cx. annulus, Anopheles sinensis, Armigeres subalbatus, and Cx. fuscocephala. Among those testing positive, Cx. tritaeniorhynchus was the predominant vector species for the transmission of JEV genotypes I and III in Taiwan. The JEV infection rate was significantly higher in the mosquitoes from the pig farms than those from the wetlands. A phylogenetic analysis of the JEV envelope gene sequences isolated from the captured mosquitoes demonstrated that the predominant JEV genotype has shifted from genotype III to genotype I (GI), providing evidence for transmission cycle maintenance and multiple introductions of the GI strains in Taiwan during 2008 to 2012. This study demonstrates the intense JEV transmission activity in Taiwan, highlights the importance of JE vaccination for controlling the epidemic, and provides valuable information for the assessment of the vaccine's efficacy. PMID:25275652

  17. Molecular Epidemiology of Japanese Encephalitis Virus in Mosquitoes in Taiwan during 2005–2012

    PubMed Central

    Su, Chien-Ling; Yang, Cheng-Fen; Teng, Hwa-Jen; Lu, Liang-Chen; Lin, Cheo; Tsai, Kun-Hsien; Chen, Yu-Yu; Chen, Li-Yu; Chang, Shu-Fen; Shu, Pei-Yun

    2014-01-01

    Japanese encephalitis (JE) is a mosquito-borne zoonotic disease caused by the Japanese encephalitis virus (JEV). Pigs and water birds are the main amplifying and maintenance hosts of the virus. In this study, we conducted a JEV survey in mosquitoes captured in pig farms and water bird wetland habitats in Taiwan during 2005 to 2012. A total of 102,633 mosquitoes were collected. Culex tritaeniorhynchus was the most common mosquito species found in the pig farms and wetlands. Among the 26 mosquito species collected, 11 tested positive for JEV by RT-PCR, including Cx. tritaeniorhynchus, Cx. annulus, Anopheles sinensis, Armigeres subalbatus, and Cx. fuscocephala. Among those testing positive, Cx. tritaeniorhynchus was the predominant vector species for the transmission of JEV genotypes I and III in Taiwan. The JEV infection rate was significantly higher in the mosquitoes from the pig farms than those from the wetlands. A phylogenetic analysis of the JEV envelope gene sequences isolated from the captured mosquitoes demonstrated that the predominant JEV genotype has shifted from genotype III to genotype I (GI), providing evidence for transmission cycle maintenance and multiple introductions of the GI strains in Taiwan during 2008 to 2012. This study demonstrates the intense JEV transmission activity in Taiwan, highlights the importance of JE vaccination for controlling the epidemic, and provides valuable information for the assessment of the vaccine's efficacy. PMID:25275652

  18. Inhibition of Japanese encephalitis virus infection by the sulfated polysaccharide extracts from Ulva lactuca.

    PubMed

    Chiu, Ya-Huang; Chan, Yi-Lin; Li, Tsung-Lin; Wu, Chang-Jer

    2012-08-01

    Japanese encephalitis virus (JEV), a neurotropic flavivirus, is one of the major causes of acute encephalitis in humans. After infection, inflammatory reactions and neurological diseases often develop. Still there are no effective drugs available against virus infection. Recently, extracts of algae have been shown to possess a broad range of biological activities including antivirus activity. In this study, we identified that the sulfated polysaccharide extracts from Ulva lactuca can inhibit JEV infection in Vero cells. Mechanistic studies further revealed that the Ulva sulfated polysaccharide extracts can block virus adsorption and thus make the virus unable to enter cells. The Ulva sulfated polysaccharide extracts also effectively decrease the production of pro-inflammatory cytokines in the JEV-infected primary mixed glia cells. In an animal study, the JEV-infected C3H/HeN mice appeared to have neurobehavioral abnormalities on the fifth day and died on the seventh day post infection. However, the JEV-infected mice pretreated with the Ulva sulfated polysaccharide extracts can delay the onset of hind limb paralysis and thereby prevent mice from death. PMID:22193590

  19. Review of Climate, Landscape, and Viral Genetics as Drivers of the Japanese Encephalitis Virus Ecology

    PubMed Central

    Le Flohic, Guillaume; Porphyre, Vincent; Gonzalez, Jean-Paul

    2013-01-01

    The Japanese encephalitis virus (JEV), an arthropod-born Flavivirus, is the major cause of viral encephalitis, responsible for 10,000–15,000 deaths each year, yet is a neglected tropical disease. Since the JEV distribution area has been large and continuously extending toward new Asian and Australasian regions, it is considered an emerging and reemerging pathogen. Despite large effective immunization campaigns, Japanese encephalitis remains a disease of global health concern. JEV zoonotic transmission cycles may be either wild or domestic: the first involves wading birds as wild amplifying hosts; the second involves pigs as the main domestic amplifying hosts. Culex mosquito species, especially Cx. tritaeniorhynchus, are the main competent vectors. Although five JEV genotypes circulate, neither clear-cut genotype-phenotype relationship nor clear variations in genotype fitness to hosts or vectors have been identified. Instead, the molecular epidemiology appears highly dependent on vectors, hosts' biology, and on a set of environmental factors. At global scale, climate, land cover, and land use, otherwise strongly dependent on human activities, affect the abundance of JEV vectors, and of wild and domestic hosts. Chiefly, the increase of rice-cultivated surface, intensively used by wading birds, and of pig production in Asia has provided a high availability of resources to mosquito vectors, enhancing the JEV maintenance, amplification, and transmission. At fine scale, the characteristics (density, size, spatial arrangement) of three landscape elements (paddy fields, pig farms, human habitations) facilitate or impede movement of vectors, then determine how the JEV interacts with hosts and vectors and ultimately the infection risk to humans. If the JEV is introduced in a favorable landscape, either by live infected animals or by vectors, then the virus can emerge and become a major threat for human health. Multidisciplinary research is essential to shed light on the

  20. Flaviviruses, an expanding threat in public health: focus on dengue, West Nile, and Japanese encephalitis virus.

    PubMed

    Daep, Carlo Amorin; Muñoz-Jordán, Jorge L; Eugenin, Eliseo Alberto

    2014-12-01

    The flaviviruses dengue, West Nile, and Japanese encephalitis represent three major mosquito-borne viruses worldwide. These pathogens impact the lives of millions of individuals and potentially could affect non-endemic areas already colonized by mosquito vectors. Unintentional transport of infected vectors (Aedes and Culex spp.), traveling within endemic areas, rapid adaptation of the insects into new geographic locations, climate change, and lack of medical surveillance have greatly contributed to the increase in flaviviral infections worldwide. The mechanisms by which flaviviruses alter the immune and the central nervous system have only recently been examined despite the alarming number of infections, related deaths, and increasing global distribution. In this review, we will discuss the expansion of the geographic areas affected by flaviviruses, the potential threats to previously unaffected countries, the mechanisms of pathogenesis, and the potential therapeutic interventions to limit the devastating consequences of these viruses. PMID:25287260

  1. Flaviviruses, an expanding threat in public health: focus on Dengue, West Nile, and Japanese encephalitis virus

    PubMed Central

    Daep, Carlo Amorin; Muñoz-Jordán, Jorge L.; Eugenin, Eliseo Alberto

    2014-01-01

    The flaviviruses Dengue, West Nile, and Japanese encephalitis represent three major mosquito-borne viruses worldwide. These pathogens impact the lives of millions of individuals and potentially could affect non-endemic areas already colonized by mosquito vectors. Unintentional transport of infected vectors (Aedes and Culex sp), traveling within endemic areas, rapid adaptation of the insects into new geographic locations, climate change, and lack of medical surveillance have greatly contributed to the increase in flaviviral infections worldwide. The mechanisms by which flaviviruses alter the immune and the central nervous system have only recently been examined despite the alarming number of infections, related deaths, and increasing global distribution. In this review, we will discuss the expansion of the geographic areas affected by flaviviruses, the potential threats to previously unaffected countries, the mechanisms of pathogenesis, and the potential therapeutic interventions to limit the devastating consequences of these viruses. PMID:25287260

  2. Human T cell responses to Japanese encephalitis virus in health and disease.

    PubMed

    Turtle, Lance; Bali, Tanushka; Buxton, Gemma; Chib, Savita; Chan, Sajesh; Soni, Mohammed; Hussain, Mohammed; Isenman, Heather; Fadnis, Prachi; Venkataswamy, Manjunatha M; Satishkumar, Vishali; Lewthwaite, Penny; Kurioka, Ayako; Krishna, Srinivasa; Shankar, M Veera; Ahmed, Riyaz; Begum, Ashia; Ravi, Vasanthapuram; Desai, Anita; Yoksan, Sutee; Fernandez, Stefan; Willberg, Christian B; Kloverpris, Henrik N; Conlon, Christopher; Klenerman, Paul; Satchidanandam, Vijaya; Solomon, Tom

    2016-06-27

    Japanese encephalitis (JE) virus (JEV) is an important cause of encephalitis in children of South and Southeast Asia. However, the majority of individuals exposed to JEV only develop mild symptoms associated with long-lasting adaptive immunity. The related flavivirus dengue virus (DENV) cocirculates in many JEV-endemic areas, and clinical data suggest cross-protection between DENV and JEV. To address the role of T cell responses in protection against JEV, we conducted the first full-breadth analysis of the human memory T cell response using a synthetic peptide library. Ex vivo interferon-γ (IFN-γ) responses to JEV in healthy JEV-exposed donors were mostly CD8(+) and targeted nonstructural (NS) proteins, whereas IFN-γ responses in recovered JE patients were mostly CD4(+) and targeted structural proteins and the secreted protein NS1. Among patients, a high quality, polyfunctional CD4(+) T cell response was associated with complete recovery from JE. T cell responses from healthy donors showed a high degree of cross-reactivity to DENV that was less apparent in recovered JE patients despite equal exposure. These data reveal divergent functional CD4(+) and CD8(+) T cell responses linked to different clinical outcomes of JEV infection, associated with distinct targeting and broad flavivirus cross-reactivity including epitopes from DENV, West Nile, and Zika virus. PMID:27242166

  3. Molecular detection and genotyping of Japanese Encephalitis Virus in mosquitoes during a 2010 outbreak in the Republic of Korea

    USGS Publications Warehouse

    Seo, Hyun-Ji; Kim, Heung Chul; Klein, Terry A.; Ramey, Andrew M.; Lee, Ji-Hyee; Kyung, Soon-Goo; Park, Jee-Yong; Cho, In-Soo; Yeh, Jung-Yong

    2013-01-01

    Japanese encephalitis virus (JEV), a mosquito-borne zoonotic pathogen, is one of the major causes of viral encephalitis. To reduce the impact of Japanese encephalitis among children in the Republic of Korea (ROK), the government established a mandatory vaccination program in 1967. Through the efforts of this program only 0-7 (mean 2.1) cases of Japanese encephalitis were reported annually in the ROK during the period of 1984-2009. However, in 2010 there was an outbreak of 26 confirmed cases of Japanese encephalitis, including 7 deaths. This represented a >12-fold increase in the number of confirmed cases of Japanese encephalitis in the ROK as compared to the mean number reported over the last 26 years and a 3.7-fold increase over the highest annual number of cases during this same period (7 cases). Surveillance of adult mosquitoes was conducted during the 2010 outbreak of Japanese encephalitis in the ROK. A total of 6,328 culicine mosquitoes belonging to 12 species from 5 genera were collected at 6 survey sites from June through October 2010 and assayed by reverse-transcription polymerase chain reaction (RT-PCR) for the presence of JEV. A total of 34/371 pooled samples tested positive for JEV (29/121 Culex tritaeniorhynchus, 4/64 Cx. pipiens, and 1/26 Cx. bitaeniorhynchus) as confirmed by sequencing of the pre-membrane and envelope protein coding genes. The maximum likelihood estimates of JEV positive individuals per 1,000 culicine vectors for Cx. tritaeniorhynchus, Cx. pipiens, and Cx. bitaeniorhynchus were 11.8, 5.6, and 2.8, respectively. Sequences of the JEV pre-membrane and envelope protein coding genes amplified from the culicine mosquitoes by RT-PCR were compared with those of JEV genotypes I-V. Phylogenetic analyses support the detection of a single genotype (I) among samples collected from the ROK in 2010.

  4. Molecular Detection and Genotyping of Japanese Encephalitis Virus in Mosquitoes during a 2010 Outbreak in the Republic of Korea

    PubMed Central

    Klein, Terry A.; Ramey, Andrew M.; Lee, Ji-Hye; Kyung, Soon-Goo; Park, Jee-Yong; Cho, Yun Sang; Cho, In-Soo; Yeh, Jung-Yong

    2013-01-01

    Japanese encephalitis virus (JEV), a mosquito-borne zoonotic pathogen, is one of the major causes of viral encephalitis. To reduce the impact of Japanese encephalitis among children in the Republic of Korea (ROK), the government established a mandatory vaccination program in 1967. Through the efforts of this program only 0–7 (mean 2.1) cases of Japanese encephalitis were reported annually in the ROK during the period of 1984–2009. However, in 2010 there was an outbreak of 26 confirmed cases of Japanese encephalitis, including 7 deaths. This represented a >12-fold increase in the number of confirmed cases of Japanese encephalitis in the ROK as compared to the mean number reported over the last 26 years and a 3.7-fold increase over the highest annual number of cases during this same period (7 cases). Surveillance of adult mosquitoes was conducted during the 2010 outbreak of Japanese encephalitis in the ROK. A total of 6,328 culicine mosquitoes belonging to 12 species from 5 genera were collected at 6 survey sites from June through October 2010 and assayed by reverse-transcription polymerase chain reaction (RT-PCR) for the presence of JEV. A total of 34/371 pooled samples tested positive for JEV (29/121 Culex tritaeniorhynchus, 4/64 Cx. pipiens, and 1/26 Cx. bitaeniorhynchus) as confirmed by sequencing of the pre-membrane and envelope protein coding genes. The maximum likelihood estimates of JEV positive individuals per 1,000 culicine vectors for Cx. tritaeniorhynchus, Cx. pipiens, and Cx. bitaeniorhynchus were 11.8, 5.6, and 2.8, respectively. Sequences of the JEV pre-membrane and envelope protein coding genes amplified from the culicine mosquitoes by RT-PCR were compared with those of JEV genotypes I-V. Phylogenetic analyses support the detection of a single genotype (I) among samples collected from the ROK in 2010. PMID:23390520

  5. Characterization of codon usage pattern and influencing factors in Japanese encephalitis virus.

    PubMed

    Singh, Niraj K; Tyagi, Anuj; Kaur, Rajinder; Verma, Ramneek; Gupta, Praveen K

    2016-08-01

    Recently, several outbreaks of Japanese encephalitis (JE), caused by Japanese encephalitis virus (JEV), have been reported and it has become cause of concern across the world. In this study, detailed analysis of JEV codon usage pattern was performed. The relative synonymous codon usage (RSCU) values along with mean effective number of codons (ENC) value of 55.30 indicated the presence of low codon usages bias in JEV. The effect of mutational pressure on codon usage bias was confirmed by significant correlations of A3s, U3s, G3s, C3s, GC3s, ENC values, with overall nucleotide contents (A%, U%, G%, C%, and GC%). The correlation analysis of A3s, U3s, G3s, C3s, GC3s, with axis values of correspondence analysis (CoA) further confirmed the role of mutational pressure. However, the correlation analysis of Gravy values and Aroma values with A3s, U3s, G3s, C3s, and GC3s, indicated the presence of natural selection on codon usage bias in addition to mutational pressure. The natural selection was further confirmed by codon adaptation index (CAI) analysis. Additionally, relative dinucleotide frequencies, geographical distribution, and evolutionary processes also influenced the codon usage pattern to some extent. PMID:27189042

  6. Yellow Fever/Japanese Encephalitis Chimeric Viruses: Construction and Biological Properties

    PubMed Central

    Chambers, Thomas J.; Nestorowicz, Ann; Mason, Peter W.; Rice, Charles M.

    1999-01-01

    A system has been developed for generating chimeric yellow fever/Japanese encephalitis (YF/JE) viruses from cDNA templates encoding the structural proteins prM and E of JE virus within the backbone of a molecular clone of the YF17D strain. Chimeric viruses incorporating the proteins of two JE strains, SA14-14-2 (human vaccine strain) and JE Nakayama (JE-N [virulent mouse brain-passaged strain]), were studied in cell culture and laboratory mice. The JE envelope protein (E) retained antigenic and biological properties when expressed with its prM protein together with the YF capsid; however, viable chimeric viruses incorporating the entire JE structural region (C-prM-E) could not be obtained. YF/JE(prM-E) chimeric viruses grew efficiently in cells of vertebrate or mosquito origin compared to the parental viruses. The YF/JE SA14-14-2 virus was unable to kill young adult mice by intracerebral challenge, even at doses of 106 PFU. In contrast, the YF/JE-N virus was neurovirulent, but the phenotype resembled parental YF virus rather than JE-N. Ten predicted amino acid differences distinguish the JE E proteins of the two chimeric viruses, therefore implicating one or more residues as virus-specific determinants of mouse neurovirulence in this chimeric system. This study indicates the feasibility of expressing protective antigens of JE virus in the context of a live, attenuated flavivirus vaccine strain (YF17D) and also establishes a genetic system for investigating the molecular basis for neurovirulence determinants encoded within the JE E protein. PMID:10074160

  7. Ecological Niche Modeling to Estimate the Distribution of Japanese Encephalitis Virus in Asia

    PubMed Central

    Miller, Robin H.; Masuoka, Penny; Klein, Terry A.; Kim, Heung-Chul; Somer, Todd; Grieco, John

    2012-01-01

    Background Culex tritaeniorhynchus is the primary vector of Japanese encephalitis virus (JEV), a leading cause of encephalitis in Asia. JEV is transmitted in an enzootic cycle involving large wading birds as the reservoirs and swine as amplifying hosts. The development of a JEV vaccine reduced the number of JE cases in regions with comprehensive childhood vaccination programs, such as in Japan and the Republic of Korea. However, the lack of vaccine programs or insufficient coverage of populations in other endemic countries leaves many people susceptible to JEV. The aim of this study was to predict the distribution of Culex tritaeniorhynchus using ecological niche modeling. Methods/Principal Findings An ecological niche model was constructed using the Maxent program to map the areas with suitable environmental conditions for the Cx. tritaeniorhynchus vector. Program input consisted of environmental data (temperature, elevation, rainfall) and known locations of vector presence resulting from an extensive literature search and records from MosquitoMap. The statistically significant Maxent model of the estimated probability of Cx. tritaeniorhynchus presence showed that the mean temperatures of the wettest quarter had the greatest impact on the model. Further, the majority of human Japanese encephalitis (JE) cases were located in regions with higher estimated probability of Cx. tritaeniorhynchus presence. Conclusions/Significance Our ecological niche model of the estimated probability of Cx. tritaeniorhynchus presence provides a framework for better allocation of vector control resources, particularly in locations where JEV vaccinations are unavailable. Furthermore, this model provides estimates of vector probability that could improve vector surveillance programs and JE control efforts. PMID:22724030

  8. Characterization of putative Japanese encephalitis virus receptor molecules on microglial cells.

    PubMed

    Thongtan, Thananya; Wikan, Nitwara; Wintachai, Phitchayapak; Rattanarungsan, Chutima; Srisomsap, Chantragan; Cheepsunthorn, Poonlarp; Smith, Duncan R

    2012-04-01

    Japanese encephalitis virus (JEV) a mosquito-borne flavivirus is a major cause of viral encephalitis in Asia. While the principle target cells for JEV in the central nervous system are believed to be neurons, microglia are activated in response to JEV and have been proposed to act as a long lasting virus reservoir. Viral attachment to a host cell is the first step of the viral entry process and is a critical mediator of tissue tropism. This study sought to identify molecules associated with JEV entry to microglial cells. Virus overlay protein-binding assay (VOPBA) and liquid chromatography-mass spectrometry (LC/MS/MS) identified the 37/67 kDa high-affinity laminin receptor protein and nucleolin as a potential JEV-binding proteins. These proteins were subsequently investigated for a contribution to JEV entry to mouse microglial BV-2 cells together with other possible candidate receptor molecules including Hsp70, Hsp90, GRP78, CD14, and CD4. In antibody mediated inhibition of infection experiments, both anti-laminin receptor and anti-CD4 antibodies significantly reduced virus entry while anti-Hsp70 and 90 antibodies produced a slight reduction. Significant inhibition of virus entry (up to 80%) was observed in the presence of lipopolysaccharide (LPS) which resulted in a complete down-regulation of CD4 and moderate down-regulation of CD14. These results suggest that multiple receptor proteins may mediate the entry of JEV to microglial cells, with CD4 playing a major role. PMID:22337301

  9. Molecular characterization of Japanese encephalitis virus strains prevalent in Chinese swine herds

    PubMed Central

    Zheng, Hao; Shan, Tongling; Deng, Yu; Sun, Chunqing; Yuan, Shishan; Yin, Yang

    2013-01-01

    Japanese encephalitis virus (JEV) is the leading cause of viral encephalitis in Asia and domestic pigs serve as the amplifying hosts. In the present study, the full genomic sequences of two JEV strains (HEN0701 and SH0601) isolated from pigs in China were determined and compared with other 12 JEV strains deposited in GenBank. These two strains had an 88.8% nucleotide sequence similarity and 97.9% deduced amino acid sequence homology. HEN0701 had high nucleotide sequence and high amino acid sequence identity with genotype I (GI) strains, while SH0601 had high nucleotide sequence and high amino acid sequence identity with GIII strains at both the gene and full genome levels. Further phylogenetic analysis showed that HEN0701 belonged to the JEV GI group and SH0601 was classified as a GIII strain. Analysis of codon usage showed there were a few differences between the GI and GIII strains in nucleotide composition and codon usage for the open reading frames. PMID:23388434

  10. Circulation of Japanese Encephalitis Virus in Pigs and Mosquito Vectors within Can Tho City, Vietnam

    PubMed Central

    Lindahl, Johanna F.; Ståhl, Karl; Chirico, Jan; Boqvist, Sofia; Thu, Ho Thi Viet; Magnusson, Ulf

    2013-01-01

    Japanese encephalitis virus (JEV) is a mosquito-borne, zoonotic flavivirus causing encephalitis in humans and reproductive disorder in pigs. JEV is present in large parts of Asia, where urbanization is high. Households within and outside Can Tho city, South Vietnam, were selected to monitor circulation of JEV. A nested RT-PCR was established to detect the presence of JEV in mosquitoes whereas sera from pigs belonging to households within the province were analyzed for the presence of antibodies to JEV. A total of 7885 mosquitoes were collected and divided into 352 pools whereof seven were JEV-positive, six of which were collected within the city. Fragments from four pools clustered with JEV genotype III and three with genotype I. Of the 43 pigs sampled inside the city 100% had JEV antibodies. Our study demonstrates exposure to JEV in pigs, and co-circulation of JEV genotype I and III in mosquitoes within an urban environment in South Vietnam. Thus, although JEV has mainly been considered a rural disease, the potential for transmission in urban areas cannot be ignored. PMID:23593520

  11. Characterization of homologous defective interfering RNA during persistent infection of Vero cells with Japanese encephalitis virus.

    PubMed

    Yoon, Sung Wook; Lee, Sang-Yong; Won, Sung-Yong; Park, Sun-Hee; Park, Soo-Young; Jeong, Yong Seok

    2006-02-28

    It has been suggested that defective interfering (DI) RNA contributes to the persistence of Japanese en-cephalitis virus (JEV). In this study, we characterized molecular and biological aspects of the DI RNA and its relation to viral persistence. We identified a homolo-gous DI virus intimately associated with JEV persis-tence in Vero cells. The production of DI RNA during undiluted serial passages of JEV coincided with the appearance of cells refractory to acute infection with JEV. We also established a Vero cell clone with a per-sistent JEV infection in which the DI RNA co-replicated efficiently at the expense of helper virus. The infectious virus yield of the clone fluctuated dur-ing its growth depending upon the amount of DI RNA accumulated in the previous replication cycle. Identifi-cation of the corresponding negative-sense RNA of the DI RNA indicated that the DI RNA functioned as a replication unit. Most of the DI RNA molecules re-tained their open reading frames despite a large dele-tion, encompassing most of the prM, the entire E, and the 5' half of the NS1 gene. Taken together, these ob-servations suggest that the generation of homologous DI RNA during successive JEV acute infections in Vero cells probably participates actively in persistent JEV infection. PMID:16511353

  12. Travel-acquired Japanese encephalitis and vaccination considerations.

    PubMed

    Pavli, Androula; Maltezou, Helena C

    2015-09-01

    Japanese encephalitis (JE) is a serious arboviral disease caused by a virus of the genus Flavivirus. Japanese encephalitis is the most common vaccine-preventable virus causing encephalitis in Asia, affecting more than 50,000 persons and leading to 15,000 fatalities per year in endemic countries. For most travelers to Asia, the risk of Japanese encephalitis infection is extremely low and depends on destination, duration of travel, season, and activities. This article reviews travel-acquired Japanese encephalitis with a focus on epidemiology and prevention in the light of the newly available options for active immunization against Japanese encephalitis which have become available, and of the increasing popularity of travels to Japanese encephalitis endemic countries. PMID:26409731

  13. Antibodies to H5 subtype avian influenza virus and Japanese encephalitis virus in northern pintails (Anas acuta) sampled in Japan

    USGS Publications Warehouse

    Ramey, Andy M.; Spackman, Erica; Yeh, Jung-Yong; Fujita, Go; Konishi, Kan; Reed, John A.; Wilcox, Benjamin R.; Brown, Justin D.; Stallknecht, David E.

    2013-01-01

    Blood samples from 105 northern pintails (Anas acuta) captured on Hokkaido, Japan were tested for antibodies to avian influenza virus (AIV), Japanese encephalitis virus (JEV), and West Nile virus (WNV) to assess possible involvement of this species in the spread of economically important and potentially zoonotic pathogens. Antibodies to AIV were detected in 64 of 105 samples (61%). Of the 64 positives, 95% and 81% inhibited agglutination of two different H5 AIV antigens (H5N1 and H5N9), respectively. Antibodies to JEV and WNV were detected in five (5%) and none of the samples, respectively. Results provide evidence for prior exposure of migrating northern pintails to H5 AIV which couldhave implications for viral shedding and disease occurrence. Results also provide evidence for limited involvement of this species in the transmission and spread of flaviviruses during spring migration.

  14. Comparison of Four Serological Tests for Detecting Antibodies to Japanese Encephalitis Virus after Vaccination in Children

    PubMed Central

    Cha, Go Woon; Cho, Jung Eun; Ju, Young Ran; Hong, Young-Jin; Han, Myung Guk; Lee, Won-Ja; Choi, Eui Yul; Jeong, Young Eui

    2014-01-01

    Objectives Several different methods are currently used to detect antibodies to Japanese encephalitis virus (JEV) in serum samples or cerebrospinal fluid. These methods include the plaque reduction neutralization test (PRNT), the hemagglutination inhibition (HI) test, indirect immunofluorescence assay (IFA), and enzyme-linked immunosorbent assay (ELISA). The purpose of this study was to compare the performance of each method in detecting vaccine-induced antibodies to JEV. Methods The study included 29 children who had completed a primary immunization schedule with an inactivated vaccine against JEV derived from mouse brain (n = 15) or a live attenuated SA14-14-2 vaccine (n = 14). Serum samples were collected between 3 months and 47 months after the last immunization. The serum samples were tested by performing the PRNT, HI test, in-house IFA, and commercial ELISA. The antibody detection rates were compared between tests. Results All 29 serum samples were positive with the PRNT, showing antibody titers from 1:20 to 1:2560. The HI test showed positive rates of 86.7% (13/15) and 71.4% (10/14) in the inactivated and live attenuated vaccine groups, respectively. The results of the IFA for immunoglobulin (Ig)G were positive in 53.3% (8/15) of children in the inactivated vaccine group and 35.7% (5/14) in the live attenuated vaccine group. Neither the IFA nor ELISA detected JEV IgM antibodies in any of the 29 children. Conclusion These results show that detection rates of vaccine-induced antibodies to JEV have a wide range (0–100%) depending on the testing method as well as the time since immunization and individual differences between children. These findings are helpful in interpreting serological test results for the diagnosis of Japanese encephalitis in situations where vaccines are widely administered. PMID:25389515

  15. Experimental evidence that RNA recombination occurs in the Japanese encephalitis virus

    SciTech Connect

    Chuang, C.-K.; Chen, W.-J.

    2009-11-25

    Due to the lack of a proofreading function and error-repairing ability of genomic RNA, accumulated mutations are known to be a force driving viral evolution in the genus Flavivirus, including the Japanese encephalitis (JE) virus. Based on sequencing data, RNA recombination was recently postulated to be another factor associated with genomic variations in these viruses. We herein provide experimental evidence to demonstrate the occurrence of RNA recombination in the JE virus using two local pure clones (T1P1-S1 and CJN-S1) respectively derived from the local strains, T1P1 and CJN. Based on results from a restriction fragment length polymorphism (RFLP) assay on the C/preM junction comprising a fragment of 868 nucleotides (nt 10-877), the recombinant progeny virus was primarily formed in BHK-21 cells that had been co-infected with the two clones used in this study. Nine of 20 recombinant forms of the JE virus had a crossover in the nt 123-323 region. Sequencing data derived from these recombinants revealed that no nucleotide deletion or insertion occurred in this region favoring crossovers, indicating that precisely, not aberrantly, homologous recombination was involved. With site-directed mutagenesis, three stem-loop secondary structures were destabilized and re-stabilized in sequence, leading to changes in the frequency of recombination. This suggests that the conformation, not the free energy, of the secondary structure is important in modulating RNA recombination of the virus. It was concluded that because RNA recombination generates genetic diversity in the JE virus, this must be considered particularly in studies of viral evolution, epidemiology, and possible vaccine safety.

  16. Comparison of the antigenic relationship between Japanese encephalitis virus genotypes 1 and 3

    PubMed Central

    2016-01-01

    Purpose The Japanese encephalitis virus (JEV) genotype circulating in Korea has changed from G3 to G1. Therefore, the purpose of this study was to compare the antigenic relationship between the two genotypes by using antibody tests. Materials and Methods Blood samples from 42 sows and 216 horses were collected, and their seroprevalence was monitored using the hemagglutination inhibition and virus neutralization tests. Antisera against JEV G1 and G3 were isolated and prepared from guinea pigs. The cross-reactivity of these two viruses was then compared using the neutralizing antibody test. Results We found that there was a difference in the seropositive ratios of JEV G1 and G3. However, the difference was dependent on the antibody test used. There was also an observed difference in the antigenicity between the two genotypes, as ascertained using the neutralizing antibody test. Conclusion There is an evident difference in JEV antigenicity between the genotypes G1 and G3. Therefore, we propose monitoring of the seroprevalence of JEV, and reevaluating the antigenicity of the current vaccine by using the relevant tests. PMID:26866021

  17. Complete genome sequence of two genotype III Japanese encephalitis virus isolates from West Bengal, India

    PubMed Central

    Taraphdar, Debjani; Chatterjee, Shyamalendu

    2015-01-01

    Background & objectives: Japanese encephalitis (JE), caused by a mosquito-borne virus JE virus (JEV), is a serious health problem in West Bengal, India. In this study, we report the complete genome sequence of two JEV isolates from West Bengal. The amino acid and nucleotide sequence homology was compared with other Indian strains. Methods: Two JEV isolates (IND-WB-JE1 and IND-WB-JE2) obtained in 2008 and 2010, respectively, from two districts of the State of West Bengal, respectively were analyzed for genetic variations by sequencing the 10934 bp whole genome of the virus. Of these two districts, one was covered under JE vaccination programme in 2007. Results: Phylogenetic analysis showed that both the isolates belonged to the genotype III. A total of 16 mutations were identified in the two isolates studied with respect to Vellore P20778 strain. One unique mutation A3215S was only found in IND-WB-JE2 isolate, but not in the isolate IND-WB-JE1. These two isolates showed maximum homology with P20778 strain of India. Interpretation & conclusions: This study reports on complete gene based phylogenetic analysis of JEV isolates from the State of West Bengal. It was evident from the results that JEV was still under circulation in both vaccine covered and not covered districts of West Bengal. PMID:26261169

  18. Comprehensive Mapping Antigenic Epitopes of NS1 Protein of Japanese Encephalitis Virus with Monoclonal Antibodies.

    PubMed

    Hua, Rong-Hong; Liu, Li-Ke; Chen, Zhen-Shi; Li, Ye-Nan; Bu, Zhi-Gao

    2013-01-01

    Japanese encephalitis virus (JEV) non-structural protein 1 (NS1) contributes to virus replication and elicits protective immune responses during infection. JEV NS1-specific antibody responses could be a target in the differential diagnosis of different flavivirus infections. However, the epitopes on JEV NS1 are poorly characterized. The present study describes the full mapping of linear B-cell epitopes in JEV NS1. We generated eleven NS1-specific monoclonal antibodies from mice immunized with recombinant NS1. For epitope mapping of monoclonal antibodies, a set of 51 partially-overlapping peptides covering the entire NS1 protein were expressed with a GST-tag and then screened using monoclonal antibodies. Through enzyme-linked immunosorbent assay (ELISA), five linear epitope-containing peptides were identified. By sequentially removing amino acid residues from the carboxy and amino terminal of peptides, the minimal units of the five linear epitopes were identified and confirmed using monoclonal antibodies. Five linear epitopes are located in amino acids residues (5)AIDITRK(11), (72)RDELNVL(78), (251)KSKHNRREGY(260), (269)DENGIVLD(276), and (341)DETTLVRS(348). Furthermore, it was found that the epitopes are highly conserved among JEV strains through sequence alignment. Notably, none of the homologous regions on NS1 proteins from other flaviviruses reacted with the MAbs when they were tested for cross-reactivity, and all five epitope peptides were not recognized by sera against West Nile virus or Dengue virus. These novel virus-specific linear B-cell epitopes of JEV NS1 would benefit the development of new vaccines and diagnostic assays. PMID:23825668

  19. Antiviral activity of Rheum palmatum methanol extract and chrysophanol against Japanese encephalitis virus.

    PubMed

    Chang, Shu-Jen; Huang, Su-Hua; Lin, Ying-Ju; Tsou, Yi-Yun; Lin, Cheng-Wen

    2014-01-01

    Rheum palmatum, Chinese traditional herb, exhibits a great variety of anti-cancer and anti-viruses properties. This study rates antiviral activity of R. palmatum extracts and its components against Japanese encephalitis virus (JEV) in vitro. Methanol extract of R. palmatum contained higher levels of aloe emodin, chrysophanol, rhein, emodin and physcion than water extract. Methanol extract (IC₅₀ = 15.04 μg/ml) exhibited more potent inhibitory effects on JEV plaque reduction than water extract (IC₅₀ = 51.41 μg/ml). Meanwhile, IC₅₀ values determined by plaque reduction assay were 15.82 μg/ml for chrysophanol and 17.39 μg/ml for aloe-emodin, respectively. Virucidal activity of agents correlated with anti-JEV activity, while virucidal IC₅₀ values were 7.58 μg/ml for methanol extract, 17.36 μg/ml for water extract, 0.75 μg/ml for chrysophanol and 0.46 μg/ml for aloe-emodin, respectively. In addition, 10 μg/ml of extract, chrysophanol or aloe emodin caused 90 % inhibition of JEV yields in cells and significantly activated gamma activated sequence-driven promoters. Hence, methanol extract of R. palmatum and chrysophanol with high therapeutic index might be useful for development of antiviral agents against JEV. PMID:24395532

  20. Epidemiological Study of Japanese Encephalitis Virus in Vientiane, Lao PDR, in 1990s

    PubMed Central

    Saito, Mika; Soukaloun, Douangdao; Phongsavath, Khampe; Phommasack, Bounlay; Makino, Yoshihiro

    2015-01-01

    Phylogenetic analysis of Japanese encephalitis virus (JEV) was conducted using core-premembrane and envelope gene sequence data of two strains from Vientiane, Lao People's Democratic Republic, in 1993 and five from Okinawa, Japan, in 2002 and 2003, and previously published strains. The two Vientiane strains designated as LaVS56 and LaVS145 belonged to genotype 1 (G1) and the same subcluster of G1 as Australian strain in 2000, Thai strains in 1982–1985 and 2004-2005, and Vietnamese strain in 2005, but were distinct from the subcluster of recently distributing G1 strains widely in Asia including Okinawan strains and recent Lao strain in 2009. These clusters with own distinct distributions indicated involvements of different mechanisms and routes of spreading viruses and clarified that Australian G1 strain is from Southeast Asia, not from East Asia. Both Vientiane strains were antigenically close to P19-Br (G1, isolate, Thailand), but distinct from Nakayama (G3, prototype strain, Japan), Beijing-1 (G3, laboratory strain, China), and JaGAr#01 (G3, laboratory strain, Japan), demonstrated by cross-neutralization tests using polyclonal antisera. These results together with seroepidemiologic study conducted in Vientiane strongly suggest that diversified JEV cocirculated there in early 1990s. PMID:25695095

  1. Isolation and genetic characterization of Japanese encephalitis virus from equines in India

    PubMed Central

    Singha, Harisankar; Singh, Birendra K.; Virmani, Nitin; Kumar, Sanjay; Singh, Raj K.

    2012-01-01

    Japanese encephalitis (JE) is an important vector-borne viral disease of humans and horses in Asia. JE outbreaks occur regularly amongst humans in certain parts of India and sporadic cases occur among horses. In this study, JE seroprevalence and evidence of JE virus (JEV) infection among horses in Haryana (India) is described. Antibodies against JEV were detected in 67 out of 637 (10.5%) horses screened between 2006 and 2010. Two foals exhibiting neurological signs were positive for JEV RNA by RT-PCR; JEV was isolated from the serum of one of the foals collected on the second day of illness. This is the first report of JEV isolation from a horse in India. Furthermore, a pool of mosquitoes collected from the premises housing these foals was positive for JEV RNA by RT-PCR. Three structural genes, capsid (C), premembrane (prM), and envelope (E) of the isolated virus (JE/eq/India/H225/2009) spanning 2,500 nucleotides (from 134 to 2,633) were cloned and sequenced. BLAST results showed that these genes had a greater than 97% nucleotide sequence identity with different human JEV isolates from India. Phylogenetic analysis based on E- and C/prM genes indicated that the equine JEV isolate belonged to genotype III and was closely related to the Vellore group of JEV isolates from India. PMID:22705732

  2. Defective interfering RNAs of Japanese encephalitis virus found in mosquito cells and correlation with persistent infection.

    PubMed

    Tsai, Kuen-Nan; Tsang, Shih-Fang; Huang, Chung-Hao; Chang, Ruey-Yi

    2007-03-01

    Defective interfering (DI) RNAs are deletion mutants of viral genomes that are known in many cases to contribute to persistent infection and modification of viral pathogenesis. Cell type also plays a critical role in the establishment of viral persistence. In this study we have identified for the first time the generation of DI RNAs of Japanese encephalitis virus in C6/36 mosquito cells. A persistent infection was established by replacing growth medium on surviving cells and continued cell passaging. Persistent infection was demonstrated by a continual release of infectious virus, fluorescent antibody staining, and Northern analysis. A population of DI RNAs of approximately 8.2-9.7 kb, not detectable in acutely infected cells, became apparent in the persistently infected cells by 25 days postinfection. Sequence analyses revealed a population of DI RNAs that contained in-frame deletions of 1.3-2.8 kb covering the region of the E gene and some flanking C or prM and NS1 gene sequences. Transcripts from one cDNA clone of a DI RNA replicated in uninfected mosquito cells as demonstrated by RT-PCR. DI RNA-containing virions in supernatant fluids from persistently infected mosquito cells could be used to establish persistent infection in BHK-21 cells. The correlation of DI RNA presence with cell survival suggests that DI RNAs are contributing mechanistically to the establishment of persistent infection in both the mosquito and mammalian cells. PMID:17134784

  3. Susceptibility of Human Embryonic Stem Cell-Derived Neural Cells to Japanese Encephalitis Virus Infection

    PubMed Central

    Shen, Shih-Cheng; Shen, Ching-I; Lin, Ho; Chen, Chun-Jung; Chang, Chia-Yu; Chen, Sheng-Mei; Lee, Hsiu-Chin; Lai, Ping-Shan; Su, Hong-Lin

    2014-01-01

    Pluripotent human embryonic stem cells (hESCs) can be efficiently directed to become immature neuroepithelial precursor cells (NPCs) and functional mature neural cells, including neurotransmitter-secreting neurons and glial cells. Investigating the susceptibility of these hESCs-derived neural cells to neurotrophic viruses, such as Japanese encephalitis virus (JEV), provides insight into the viral cell tropism in the infected human brain. We demonstrate that hESC-derived NPCs are highly vulnerable to JEV infection at a low multiplicity of infection (MOI). In addition, glial fibrillary acid protein (GFAP)-expressing glial cells are also susceptible to JEV infection. In contrast, only a few mature neurons were infected at MOI 10 or higher on the third day post-infection. In addition, functional neurotransmitter-secreting neurons are also resistant to JEV infection at high MOI. Moreover, we discover that vimentin intermediate filament, reported as a putative neurovirulent JEV receptor, is highly expressed in NPCs and glial cells, but not mature neurons. These results indicate that the expression of vimentin in neural cells correlates to the cell tropism of JEV. Finally, we further demonstrate that membranous vimentin is necessary for the susceptibility of hESC-derived NPCs to JEV infection. PMID:25517725

  4. Cross-protection induced by Japanese encephalitis vaccines against different genotypes of Dengue viruses in mice

    PubMed Central

    Li, Jieqiong; Gao, Na; Fan, Dongying; Chen, Hui; Sheng, Ziyang; Fu, Shihong; Liang, Guodong; An, Jing

    2016-01-01

    Dengue viruses (DENVs) and Japanese encephalitis virus (JEV) are closely related mosquito-borne flaviviruses that cause very high global disease burdens. Although cross-reactivity and cross-protection within flaviviruses have been demonstrated, the effect of JEV vaccination on susceptibility to DENV infection has not been well elucidated. In this study, we found that vaccination with the JEV inactivated vaccine (INV) and live attenuated vaccine (LAV) could induce cross-immune responses and cross-protection against DENV1-4 in mice. Despite the theoretical risk of immune enhancement, no increased mortality was observed in our mouse model. Additionally, low but consistently detectable cross-neutralizing antibodies against DENV2 and DENV3 were also observed in the sera of JEV vaccine-immunized human donors. The results suggested that both JEV-LAV and JEV-INV could elicit strong cross-immunity and protection against DENVs, indicating that inoculation with JEV vaccines may influence the distribution of DENVs in co-circulated areas and that the cross-protection induced by JEV vaccines against DENVs might provide important information in terms of DENV prevention. PMID:26818736

  5. MicroRNA transcriptome profiling of mice brains infected with Japanese encephalitis virus by RNA sequencing.

    PubMed

    Li, Xin-Feng; Cao, Rui-Bing; Luo, Jun; Fan, Jian-Ming; Wang, Jing-Man; Zhang, Yuan-Peng; Gu, Jin-Yan; Feng, Xiu-Li; Zhou, Bin; Chen, Pu-Yan

    2016-04-01

    Japanese encephalitis (JE) is a mosquito borne viral disease, caused by Japanese encephalitis virus (JEV) infection producing severe neuroinflammation in the central nervous system (CNS) with the associated disruption of the blood brain barrier. MicroRNAs (miRNAs) are a family of 21-24 nt small non-coding RNAs that play important post-transcriptional regulatory roles in gene expression and have critical roles in virus pathogenesis. We examined the potential roles of miRNAs in JEV-infected suckling mice brains and found that JEV infection changed miRNA expression profiles when the suckling mice began showing nervous symptoms. A total of 1062 known and 71 novel miRNAs were detected in JEV-infected group, accompanied with 1088 known and 75 novel miRNAs in mock controls. Among these miRNAs, one novel and 25 known miRNAs were significantly differentially expressed, including 18 up-regulated and 8 down-regulated miRNAs which were further confirmed by real-time PCR. Gene ontology (GO) and signaling pathway analysis of the predicted target mRNAs of the modulated miRNAs showed that they are correlated with the regulation of apoptosis, neuron differentiation, antiviral immunity and infiltration of mouse brain, and the validated targets of 12 differentially expressed miRNAs were enriched for the regulation of cell programmed death, proliferation, transcription, muscle organ development, erythrocyte differentiation, gene expression, plasma membrane and protein domain specific binding. KEGG analysis further reveals that the validated target genes were involved in the Pathways in cancer, Neurotrophin signaling pathway, Toll like receptor signaling pathway, Endometrial cancer and Jak-STAT signaling pathway. We constructed the interaction networks of miRNAs and their target genes according to GO terms and KEGG pathways and the expression levels of several target genes were examined. Our data provides a valuable basis for further studies on the regulatory roles of miRNAs in JE

  6. Comparison of Genotypes I and III in Japanese Encephalitis Virus Reveals Distinct Differences in Their Genetic and Host Diversity

    PubMed Central

    Han, Na; Adams, James; Chen, Ping; Guo, Zhen-yang; Zhong, Xiang-fu; Fang, Wei; Li, Na; Wen, Lei; Tao, Xiao-yan; Yuan, Zhi-ming

    2014-01-01

    ABSTRACT Japanese encephalitis (JE) is an arthropod-borne disease associated with the majority of viral encephalitis cases in the Asia-Pacific region. The causative agent, Japanese encephalitis virus (JEV), has been phylogenetically divided into five genotypes. Recent surveillance data indicate that genotype I (GI) is gradually replacing genotype III (GIII) as the dominant genotype. To investigate the mechanism behind the genotype shift and the potential consequences in terms of vaccine efficacy, human cases, and virus dissemination, we collected (i) all full-length and partial JEV molecular sequences and (ii) associated genotype and host information comprising a data set of 873 sequences. We then examined differences between the two genotypes at the genetic and epidemiological level by investigating amino acid mutations, positive selection, and host range. We found that although GI is dominant, it has fewer sites predicted to be under positive selection, a narrower host range, and significantly fewer human isolates. For the E protein, the sites under positive selection define a haplotype set for each genotype that shows striking differences in their composition and diversity, with GIII showing significantly more variety than GI. Our results suggest that GI has displaced GIII by achieving a replication cycle that is more efficient but is also more restricted in its host range. IMPORTANCE Japanese encephalitis is an arthropod-borne disease associated with the majority of viral encephalitis cases in the Asia-Pacific region. The causative agent, Japanese encephalitis virus (JEV), has been divided into five genotypes based on sequence similarity. Recent data indicate that genotype I (GI) is gradually replacing genotype III (GIII) as the dominant genotype. Understanding the reasons behind this shift and the potential consequences in terms of vaccine efficacy, human cases, and virus dissemination is important for controlling the spread of the virus and reducing human

  7. A Single Amino Acid Substitution in the NS2A Protein of Japanese Encephalitis Virus Affects Virus Propagation In Vitro but Not In Vivo

    PubMed Central

    Takamatsu, Yuki; Morita, Kouichi

    2015-01-01

    We identified a unique amino acid of NS2A113, phenylalanine, that affects the efficient propagation of two Japanese encephalitis virus strains, JaTH160 and JaOArS982, in neuroblastoma Neuro-2a cells but not in cell lines of extraneural origin. This amino acid did not affect viral loads in the brain or survival curves in mice. These findings suggest that virus propagation in vitro may not reflect the level of virus neuroinvasiveness in vivo. PMID:25787282

  8. Genetic diversity of Japanese encephalitis virus isolates obtained from the Indonesian archipelago between 1974 and 1987.

    PubMed

    Schuh, Amy J; Guzman, Hilda; Tesh, Robert B; Barrett, Alan D T

    2013-07-01

    Five genotypes (GI-V) of Japanese encephalitis virus (JEV) have been identified, all of which have distinct geographical distributions and epidemiologies. It is thought that JEV originated in the Indonesia-Malaysia region from an ancestral virus. From that ancestral virus GV diverged, followed by GIV, GIII, GII, and GI. Genotype IV appears to be confined to the Indonesia-Malaysia region, as GIV has been isolated in Indonesia from mosquitoes only, while GV has been isolated on three occasions only from a human in Malaysia and mosquitoes in China and South Korea. In contrast, GI-III viruses have been isolated throughout Asia and Australasia from a variety of hosts. Prior to this study only 13 JEV isolates collected from the Indonesian archipelago had been studied genetically. Therefore the sequences of the envelope (E) gene of 24 additional Indonesian JEV isolates, collected throughout the archipelago between 1974 and 1987, were determined and a series of molecular adaptation analyses were performed. Phylogenetic analysis indicated that over a 14-year time span three genotypes of JEV circulated throughout Indonesia, and a statistically significant association between the year of virus collection and genotype was revealed: isolates collected between 1974 and 1980 belonged to GII, isolates collected between 1980 and 1981 belonged to GIV, and isolates collected in 1987 belonged to GIII. Interestingly, three of the GII Indonesian isolates grouped with an isolate that was collected during the JE outbreak that occurred in Australia in 1995, two of the GIII Indonesian isolates were closely related to a Japanese isolate collected 40 years previously, and two Javanese GIV isolates possessed six amino acid substitutions within the E protein when compared to a previously sequenced GIV isolate collected in Flores. Several amino acids within the E protein of the Indonesian isolates were found to be under directional evolution and/or co-evolution. Conceivably, the tropical climate

  9. Genetic Diversity of Japanese Encephalitis Virus Isolates Obtained from the Indonesian Archipelago Between 1974 and 1987

    PubMed Central

    Schuh, Amy J.; Guzman, Hilda; Tesh, Robert B.

    2013-01-01

    Abstract Five genotypes (GI–V) of Japanese encephalitis virus (JEV) have been identified, all of which have distinct geographical distributions and epidemiologies. It is thought that JEV originated in the Indonesia-Malaysia region from an ancestral virus. From that ancestral virus GV diverged, followed by GIV, GIII, GII, and GI. Genotype IV appears to be confined to the Indonesia-Malaysia region, as GIV has been isolated in Indonesia from mosquitoes only, while GV has been isolated on three occasions only from a human in Malaysia and mosquitoes in China and South Korea. In contrast, GI–III viruses have been isolated throughout Asia and Australasia from a variety of hosts. Prior to this study only 13 JEV isolates collected from the Indonesian archipelago had been studied genetically. Therefore the sequences of the envelope (E) gene of 24 additional Indonesian JEV isolates, collected throughout the archipelago between 1974 and 1987, were determined and a series of molecular adaptation analyses were performed. Phylogenetic analysis indicated that over a 14-year time span three genotypes of JEV circulated throughout Indonesia, and a statistically significant association between the year of virus collection and genotype was revealed: isolates collected between 1974 and 1980 belonged to GII, isolates collected between 1980 and 1981 belonged to GIV, and isolates collected in 1987 belonged to GIII. Interestingly, three of the GII Indonesian isolates grouped with an isolate that was collected during the JE outbreak that occurred in Australia in 1995, two of the GIII Indonesian isolates were closely related to a Japanese isolate collected 40 years previously, and two Javanese GIV isolates possessed six amino acid substitutions within the E protein when compared to a previously sequenced GIV isolate collected in Flores. Several amino acids within the E protein of the Indonesian isolates were found to be under directional evolution and/or co-evolution. Conceivably, the

  10. Protective immunity of E. coli-synthesized NS1 protein of Japanese encephalitis virus.

    PubMed

    Lin, Cheng-Wen; Liu, Kuang-Ting; Huang, Hong-Da; Chen, Wei-June

    2008-02-01

    Immunogenicity and protective efficacy of recombinant Japanese encephalitis virus (JEV) NS1 proteins generated using DNA vaccines and recombinant viruses have been demonstrated to induce protection in mice against a challenge of JEV at a lethal dose. The West Nile virus NS1 region expressed in E. coli is recognized by these protective monoclonal antibodies and, in this study, we compare immunogenicity and protective immunity of the E. coli-synthesized NS1 protein with another protective immunogen, the envelope domain III (ED3). Pre-challenge, detectable titers of JEV-specific neutralizing antibody were detected in the immunized mice with E. coli-synthesized ED3 protein (PRNT50 = 1:28) and the attenuated JEV strain T1P1 (PRNT50 = 1:53), but neutralizing antibodies were undetectable in the immunized mice with E. coli-synthesized NS1 protein (PRNT50 < 1:10). However, the survival rate of the NS1-immunized mice against the JEV challenge was 87.5% (7/8), showing significantly higher levels of protection than the ED3-immunized mice, 62.5% (5/8) (P = 0.041). In addition, E. coli-synthesized NS1 protein induced a significant increase of anti-NS1 IgG1 antibodies, resulting in an ELISA titer of 100,1000 in the immunized sera before lethal JEV challenge. Surviving mice challenged with the virulent JEV strain Beijing-1 showed a ten-fold or greater rise in IgG1 and IgG2b titers of anti-NS1 antibodies, implying that the Th2 cell activation might be predominantly responsible for antibody responses and mice protection. PMID:17876533

  11. Porcine 2', 5'-oligoadenylate synthetases inhibit Japanese encephalitis virus replication in vitro.

    PubMed

    Zheng, Sheng; Zhu, Dan; Lian, Xue; Liu, Weiting; Cao, Ruibing; Chen, Puyan

    2016-05-01

    The 2', 5'-oligoadenylate synthetases (OAS) are antiviral proteins and several isoforms have been identified as flavivirus-resistance biomarkers in human and mouse. The expression kinetics and antiviral functions of porcine OAS family (OAS1, OAS2, and OASL) in PK-15 cells following infection by Japanese encephalitis virus (JEV) were evaluated in the present study. The endogenous expression of the three OAS genes was efficiently induced by IFN-α treatment in PK-15 cells. However, expression of pOAS1 and pOAS2 responded more quickly than pOASL. Infection by JEV also induced the expression of the pOAS isoforms, but at a significantly lower level than that observed following IFN-α stimulation. Transient overexpression of pOASL and pOAS1 inhibited JEV replication more efficiently than OAS2 overexpression. Interestingly, knockdown of pOAS2 expression by siRNA treatment led to the highest increase in JEV multiplication. Co-silencing of RNase L and each pOAS revealed that the anti-JEV function of pOAS1 and pOAS2 were RNase L dependent, while the antiviral activity of pOASL was not. In conclusion, all pOAS isoforms play a significant role in the response to JEV infection, and are differentially induced by different stimuli. The alternative pathways of antiviral activity stimulated by OASL require further study. PMID:26437676

  12. [Study on Spatial Dispersal and Migration Events of Japanese Encephalitis Virus].

    PubMed

    Gao, Xiaoyan; Zhou, Haiwei; Liu, Hong; Fu, Shihong; Wang, Huanyu; Guo, Zhenyang; Li, Xiaolong; Liang, Guodong

    2015-05-01

    To explore the spatial distribution mechanism of Japanese encephalitis virus (JEV), PhyML v3.0 was used to build phylogenetic tree using JEV sequences in the dataset. PAUP v4.0 and Migrapyhla softz ware were then used to analyze the migration events. The results showed that a total of 95 migration events were observed during the dispersal of JEV throughout Asia. Further analysis revealed that Thailand, and several Chinese provinces (including Shandong, Shanghai, Sichuan and Yunnan), were the main migration sources of JEV. JEV spread from these migration sources as follows: from Thailand to Australia, Cambodia, Tibet and India; from Shanghai to eastern coastal Asian regions and Yunnan; from Shandong to Korea, Zhejiang, Hubei, Shanxi and Liaoning; from Sichuan mainly to inland regions of China, as well as Vietnam and Japan; and from Yunnan to Zhejiang. This study indicated that frequent migration events occurred during the dispersal of JEV in the Asia and Pacific regions, and that Thailand, Shandong, Shanghai, Sichuan and Yunnan were the sources of JEV dispersal. PMID:26470532

  13. Susceptibility of a North American Culex quinquefasciatus to Japanese Encephalitis Virus.

    PubMed

    Huang, Yan-Jang S; Harbin, Julie N; Hettenbach, Susan M; Maki, Elin; Cohnstaedt, Lee W; Barrett, Alan D T; Higgs, Stephen; Vanlandingham, Dana L

    2015-11-01

    Japanese encephalitis virus (JEV) is a flavivirus that is transmitted by Culex (Cx.) tritaeniorhynchus in tropical and subtropical regions of Asia. The endemic transmission cycle involves domestic pigs and avian species that serve as amplification hosts; humans are incidental hosts that cannot develop a high-titer viremia sufficient for mosquito infection. Although vaccination can be an effective strategy for disease prevention and is used extensively in multiple Asian countries, unvaccinated immunologically naïve human populations can suffer from severe neurological sequelae. The potential introduction of JEV into North America would be a major threat to human and animal health. In this study, field-collected Cx. quinquefasciatus from Valdosta, Georgia, were tested for their susceptibility to JEV and their potential to develop a disseminated infection via per os infection. These results demonstrate that North American Cx. quinquefasciatus are susceptible to JEV infection and subsequent dissemination at 14 days post infection (d.p.i.). Detection of viral RNA in saliva from infected mosquitoes also indicates competent vectors for JEV can be found in North America. PMID:26565775

  14. Neutralizing activities of human immunoglobulin derived from donors in Japan against mosquito-borne flaviviruses, Japanese encephalitis virus, West Nile virus, and dengue virus

    PubMed Central

    Yunoki, Mikihiro; Kurosu, Takeshi; Koketsu, Ritsuko Kubota; Takahashi, Kazuo; Okuno, Yoshinobu; Ikuta, Kazuyoshi

    2016-01-01

    Japanese encephalitis virus (JEV), West Nile virus (WNV), and dengue virus (DenV) are causal agents of Japanese encephalitis, West Nile fever, and dengue fever, respectively. JEV is considered to be indigenized and widespread in Japan, whereas WNV and DenV are not indigenized in Japan. Globulin products seem to reflect the status of the donor population according to antivirus neutralization activity. However, the anti-JEV, -WNV, and -DenV neutralization activities of globulin products derived from donors in Japan have not been clarified. Furthermore, potential candidates for the development of an effective immunotherapeutic drug for encephalitis caused by JEV, WNV, or DenV have also not been identified. Therefore, the aim of this study was to determine the overall status of the donor population in Japan based on globulin products by evaluating anti-JEV, -WNV, and -DenV neutralizing activities of intravenous immunoglobulin. Overall, intravenous immunoglobulin products showed stable neutralizing activity against JEV but showed no or only weak activity against WNV or DenV. These results suggest that the epidemiological level against WNV and DenV in the donor population of Japan is still low, suggesting that these viruses are not yet indigenized. In addition, JEV vaccinations and/or infections in the donor population do not induce a cross-reactive antibody against WNV. PMID:27462140

  15. Neutralizing activities of human immunoglobulin derived from donors in Japan against mosquito-borne flaviviruses, Japanese encephalitis virus, West Nile virus, and dengue virus.

    PubMed

    Yunoki, Mikihiro; Kurosu, Takeshi; Koketsu, Ritsuko Kubota; Takahashi, Kazuo; Okuno, Yoshinobu; Ikuta, Kazuyoshi

    2016-01-01

    Japanese encephalitis virus (JEV), West Nile virus (WNV), and dengue virus (DenV) are causal agents of Japanese encephalitis, West Nile fever, and dengue fever, respectively. JEV is considered to be indigenized and widespread in Japan, whereas WNV and DenV are not indigenized in Japan. Globulin products seem to reflect the status of the donor population according to antivirus neutralization activity. However, the anti-JEV, -WNV, and -DenV neutralization activities of globulin products derived from donors in Japan have not been clarified. Furthermore, potential candidates for the development of an effective immunotherapeutic drug for encephalitis caused by JEV, WNV, or DenV have also not been identified. Therefore, the aim of this study was to determine the overall status of the donor population in Japan based on globulin products by evaluating anti-JEV, -WNV, and -DenV neutralizing activities of intravenous immunoglobulin. Overall, intravenous immunoglobulin products showed stable neutralizing activity against JEV but showed no or only weak activity against WNV or DenV. These results suggest that the epidemiological level against WNV and DenV in the donor population of Japan is still low, suggesting that these viruses are not yet indigenized. In addition, JEV vaccinations and/or infections in the donor population do not induce a cross-reactive antibody against WNV. PMID:27462140

  16. Recombinant Measles AIK-C Vaccine Strain Expressing the prM-E Antigen of Japanese Encephalitis Virus

    PubMed Central

    Higuchi, Akira; Toriniwa, Hiroko; Komiya, Tomoyoshi; Nakayama, Tetsuo

    2016-01-01

    An inactivated Japanese encephalitis virus (JEV) vaccine, which induces neutralizing antibodies, has been used for many years in Japan. In the present study, the JEV prM-E protein gene was cloned, inserted at the P/M junction of measles AIK-C cDNA, and an infectious virus was recovered. The JEV E protein was expressed in B95a cells infected with the recombinant virus. Cotton rats were inoculated with recombinant virus. Measles PA antibodies were detected three weeks after immunization. Neutralizing antibodies against JEV developed one week after inoculation, and EIA antibodies were detected three weeks after immunization. The measles AIK-C-based recombinant virus simultaneously induced measles and JEV immune responses, and may be a candidate for infant vaccines. Therefore, the present strategy of recombinant viruses based on a measles vaccine vector would be applicable to the platform for vaccine development. PMID:26930411

  17. Reproductive performance in sows in relation to Japanese Encephalitis Virus seropositivity in an endemic area.

    PubMed

    Lindahl, Johanna; Boqvist, Sofia; Ståhl, Karl; Thu, Ho Thi Viet; Magnusson, Ulf

    2012-02-01

    Japanese Encephalitis Virus (JEV) is considered an important reproductive pathogen in pigs. Most studies of the reproductive impact of JEV have been conducted in areas where the disease occurs in seasonal epidemics. In this study, the associations between seropositivity for JEV, measured with an IgG ELISA, and the number of piglets born alive and stillborn were investigated in a tropical area endemic for JEV in Vietnam. Sixty percent of sows from four farms in the Mekong delta of Vietnam were seropositive to JEV and the Odds Ratio for a sow being infected was highest (6.4) in sows above 3.5 years (95% confidence interval 2.2-18.3). There was an association between increasing Optical Density (OD) values from the ELISA and the number of stillborn piglets in sows less than 1.5 years, but no effect of seropositivity could be shown when all sows were studied. OD values had an effect (p = 0.04) on the number of piglets born alive in the statistical analysis only when interacting with the effect of the breeds. An increase in mean OD value of the herd was correlated (p < 0.0001) with an increase in the number of piglets born alive. In this study, there was evidence of a negative association between seropositivity for JEV and the reproductive performance only in sows less than 1.5 years in endemic areas. This could be explained by a year-round infection with the virus, which would lead to immunity in many gilts before their first pregnancy. This, in turn, may imply that JEV infection in pigs is of minor importance for the reproductive performance in endemic areas. PMID:22081319

  18. Inapparent Viral Infection of Cells In Vitro III. Manifestations of Infection of L Mouse Cells by Japanese Encephalitis Virus1

    PubMed Central

    Dubbs, D. R.; Scherer, W. F.

    1966-01-01

    Dubbs, D. R. (University of Minnesota, Minneapolis), and W. F. Scherer. Inapparent viral infection of cells in vitro. III. Manifestations of infection of L mouse cells by Japanese encephalitis virus. J. Bacteriol. 91:2349–2355. 1966.—Nine strains of Japanese encephalitis (JE) virus were propagated serially in cultures of L cells reaching titers of 103.5 to 106.3. Although cytopathic effects were not seen in cultures of contiguous L cells after infection with JE virus, cell growth was inhibited. Moreover, cell destruction was readily apparent in infected cultures of sparse, noncontiguous L cells. Differences in the size of cell population of infected and noninfected cultures (i) occurred despite only 0.2 to 3.5% of the cells in infected cultures being associated with infectious virus, (ii) were greater in actively growing cultures than in those kept in maintenance media, and (iii) were probably in part related to an interferon produced in infected cultures. Images PMID:4287589

  19. Bivalent vaccine platform based on Japanese encephalitis virus (JEV) elicits neutralizing antibodies against JEV and hepatitis C virus.

    PubMed

    Saga, Ryohei; Fujimoto, Akira; Watanabe, Noriyuki; Matsuda, Mami; Hasegawa, Makoto; Watashi, Koichi; Aizaki, Hideki; Nakamura, Noriko; Tajima, Shigeru; Takasaki, Tomohiko; Konishi, Eiji; Kato, Takanobu; Kohara, Michinori; Takeyama, Haruko; Wakita, Takaji; Suzuki, Ryosuke

    2016-01-01

    Directly acting antivirals recently have become available for the treatment of hepatitis C virus (HCV) infection, but there is no prophylactic vaccine for HCV. In the present study, we took advantage of the properties of Japanese encephalitis virus (JEV) to develop antigens for use in a HCV vaccine. Notably, the surface-exposed JEV envelope protein is tolerant of inserted foreign epitopes, permitting display of novel antigens. We identified 3 positions that permitted insertion of the HCV E2 neutralization epitope recognized by HCV1 antibody. JEV subviral particles (SVP) containing HCV-neutralization epitope (SVP-E2) were purified from culture supernatant by gel chromatography. Sera from mice immunized with SVP-E2 inhibited infection by JEV and by trans-complemented HCV particles (HCVtcp) derived from multi-genotypic viruses, whereas sera from mice immunized with synthetic E2 peptides did not show any neutralizing activity. Furthermore, sera from mice immunized with SVP-E2 neutralized HCVtcp with N415K escape mutation in E2. As with the SVP-E2 epitope-displaying particles, JEV SVPs with HCV E1 epitope also elicited neutralizing antibodies against HCV. Thus, this novel platform harboring foreign epitopes on the surface of the particle may facilitate the development of a bivalent vaccine against JEV and other pathogens. PMID:27345289

  20. Bivalent vaccine platform based on Japanese encephalitis virus (JEV) elicits neutralizing antibodies against JEV and hepatitis C virus

    PubMed Central

    Saga, Ryohei; Fujimoto, Akira; Watanabe, Noriyuki; Matsuda, Mami; Hasegawa, Makoto; Watashi, Koichi; Aizaki, Hideki; Nakamura, Noriko; Tajima, Shigeru; Takasaki, Tomohiko; Konishi, Eiji; Kato, Takanobu; Kohara, Michinori; Takeyama, Haruko; Wakita, Takaji; Suzuki, Ryosuke

    2016-01-01

    Directly acting antivirals recently have become available for the treatment of hepatitis C virus (HCV) infection, but there is no prophylactic vaccine for HCV. In the present study, we took advantage of the properties of Japanese encephalitis virus (JEV) to develop antigens for use in a HCV vaccine. Notably, the surface-exposed JEV envelope protein is tolerant of inserted foreign epitopes, permitting display of novel antigens. We identified 3 positions that permitted insertion of the HCV E2 neutralization epitope recognized by HCV1 antibody. JEV subviral particles (SVP) containing HCV-neutralization epitope (SVP-E2) were purified from culture supernatant by gel chromatography. Sera from mice immunized with SVP-E2 inhibited infection by JEV and by trans-complemented HCV particles (HCVtcp) derived from multi-genotypic viruses, whereas sera from mice immunized with synthetic E2 peptides did not show any neutralizing activity. Furthermore, sera from mice immunized with SVP-E2 neutralized HCVtcp with N415K escape mutation in E2. As with the SVP-E2 epitope-displaying particles, JEV SVPs with HCV E1 epitope also elicited neutralizing antibodies against HCV. Thus, this novel platform harboring foreign epitopes on the surface of the particle may facilitate the development of a bivalent vaccine against JEV and other pathogens. PMID:27345289

  1. Genetic instability of Japanese encephalitis virus cDNA clones propagated in Escherichia coli.

    PubMed

    Zheng, Xuchen; Tong, Wu; Liu, Fei; Liang, Chao; Gao, Fei; Li, Guoxin; Tong, Guangzhi; Zheng, Hao

    2016-04-01

    The genetic instability of Flavivirus cDNA clones in transformed bacteria is a common phenomenon. Herein, a cDNA fragment of the nucleotide (nt) 1-2913 of the genome of a flavivirus, Japanese encephalitis virus (JEV), was used to investigate factors that caused the instability of cDNA clones. Several cDNA fragments with different 5'- or 3'-termini of the 2913-nt cDNA were obtained by PCR amplification or restriction enzyme digestion and cloned into a pCR-Blunt II-TOPO vector. All the cDNA fragments were stably propagated at 25 °C. However, the 5'-untranslated region and half of the 3'-E gene could cause the instability of the 2913-nt cDNA at 37 °C. The 5'-terminus sequences of the 2913-nt fragment were subjected to testing of the prokaryotic promoter activity by luciferase assay and Western blot. The sequences of 54-120 nt of the JEV genome exhibited high prokaryotic promoter activity at 37 °C, and the activity declined markedly at 25 °C. These findings revealed that the high prokaryotic promoter activity of the 54-120 nt sequences of the JEV genome together with expression of JEV structural genes determined the instability of a JEV cDNA clone. Growth at room temperature may reduce the prokaryotic promoter activity of 5'-sequences of the JEV genome and could represent an effective way to improve the stability of flavivirus cDNA clones in host bacteria. PMID:26888374

  2. A Lentiviral Vector Expressing Japanese Encephalitis Virus-like Particles Elicits Broad Neutralizing Antibody Response in Pigs

    PubMed Central

    Souque, Philippe; Frenkiel, Marie-Pascale; Paulous, Sylvie; Garcìa-Nicolàs, Obdulio; Summerfield, Artur; Charneau, Pierre; Desprès, Philippe

    2015-01-01

    Background Japanese encephalitis virus (JEV) is the major cause of viral encephalitis in Southeast Asia. Vaccination of domestic pigs has been suggested as a “one health” strategy to reduce viral disease transmission to humans. The efficiency of two lentiviral TRIP/JEV vectors expressing the JEV envelope prM and E glycoproteins at eliciting protective humoral response was assessed in a mouse model and piglets. Methodology/Principal Findings A gene encoding the envelope proteins prM and E from a genotype 3 JEV strain was inserted into a lentiviral TRIP vector. Two lentiviral vectors TRIP/JEV were generated, each expressing the prM signal peptide followed by the prM protein and the E glycoprotein, the latter being expressed either in its native form or lacking its two C-terminal transmembrane domains. In vitro transduction of cells with the TRIP/JEV vector expressing the native prM and E resulted in the efficient secretion of virus-like particles of Japanese encephalitis virus. Immunization of BALB/c mice with TRIP/JEV vectors resulted in the production of IgGs against Japanese encephalitis virus, and the injection of a second dose one month after the prime injection greatly boosted antibody titers. The TRIP/JEV vectors elicited neutralizing antibodies against JEV strains belonging to genotypes 1, 3, and 5. Immunization of piglets with two doses of the lentiviral vector expressing JEV virus-like particles led to high titers of anti-JEV antibodies, that had efficient neutralizing activity regardless of the JEV genotype tested. Conclusions/Significance Immunization of pigs with the lentiviral vector expressing JEV virus-like particles is particularly efficient to prime antigen-specific humoral immunity and trigger neutralizing antibody responses against JEV genotypes 1, 3, and 5. The titers of neutralizing antibodies elicited by the TRIP/JEV vector are sufficient to confer protection in domestic pigs against different genotypes of JEV and this could be of a great

  3. Viral Infection of the Central Nervous System and Neuroinflammation Precede Blood-Brain Barrier Disruption during Japanese Encephalitis Virus Infection

    PubMed Central

    Li, Fang; Wang, Yueyun; Yu, Lan; Cao, Shengbo; Wang, Ke; Yuan, Jiaolong; Wang, Chong; Wang, Kunlun; Fu, Zhen F.

    2015-01-01

    ABSTRACT Japanese encephalitis is an acute zoonotic, mosquito-borne disease caused by Japanese encephalitis virus (JEV). Japanese encephalitis is characterized by extensive inflammation in the central nervous system (CNS) and disruption of the blood-brain barrier (BBB). However, the pathogenic mechanisms contributing to the BBB disruption are not known. Here, using a mouse model of intravenous JEV infection, we show that virus titers increased exponentially in the brain from 2 to 5 days postinfection. This was accompanied by an early, dramatic increase in the level of inflammatory cytokines and chemokines in the brain. Enhancement of BBB permeability, however, was not observed until day 4, suggesting that viral entry and the onset of inflammation in the CNS occurred prior to BBB damage. In vitro studies revealed that direct infection with JEV could not induce changes in the permeability of brain microvascular endothelial cell monolayers. However, brain extracts derived from symptomatic JEV-infected mice, but not from mock-infected mice, induced significant permeability of the endothelial monolayer. Consistent with a role for inflammatory mediators in BBB disruption, the administration of gamma interferon-neutralizing antibody ameliorated the enhancement of BBB permeability in JEV-infected mice. Taken together, our data suggest that JEV enters the CNS, propagates in neurons, and induces the production of inflammatory cytokines and chemokines, which result in the disruption of the BBB. IMPORTANCE Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia, resulting in 70,000 cases each year, in which approximately 20 to 30% of cases are fatal, and a high proportion of patients survive with serious neurological and psychiatric sequelae. Pathologically, JEV infection causes an acute encephalopathy accompanied by BBB dysfunction; however, the mechanism is not clear. Thus, understanding the mechanisms of BBB disruption in JEV infection is important

  4. A Novel Immunochromatographic Test Applied to a Serological Survey of Japanese Encephalitis Virus on Pig Farms in Korea

    PubMed Central

    Cha, Go-Woon; Lee, Eun Ju; Lim, Eun-Joo; Sin, Kang Suk; Park, Woo Won; Jeon, Doo Young; Han, Myung Guk; Lee, Won-Ja; Choi, Woo-Young; Jeong, Young Eui

    2015-01-01

    Among vertebrate species, pigs are a major amplifying host of Japanese encephalitis virus (JEV) and measuring their seroconversion is a reliable indicator of virus activity. Traditionally, the hemagglutination inhibition test has been used for serological testing in pigs; however, it has several limitations and, thus, a more efficient and reliable replacement test is required. In this study, we developed a new immunochromatographic test for detecting antibodies to JEV in pig serum within 15 min. Specifically, the domain III region of the JEV envelope protein was successfully expressed in soluble form and used for developing the immunochromatographic test. The test was then applied to the surveillance of Japanese encephalitis (JE) in Korea. We found that our immunochromatographic test had good sensitivity (84.8%) and specificity (97.7%) when compared with an immunofluorescence assay used as a reference test. During the surveillance of JE in Korea in 2012, the new immunochromatographic test was used to test the sera of 1,926 slaughtered pigs from eight provinces, and 228 pigs (11.8%) were found to be JEV-positive. Based on these results, we also produced an activity map of JEV, which marked the locations of pig farms in Korea that tested positive for the virus. Thus, the immunochromatographic test reported here provides a convenient and effective tool for real-time monitoring of JEV activity in pigs. PMID:25992769

  5. Cross-protection between West Nile and Japanese encephalitis viruses in red-winged blackbirds (Agelaius phoeniceus).

    PubMed

    Nemeth, Nicole M; Bosco-Lauth, Angela M; Bowen, Richard A

    2009-09-01

    Similar to West Nile virus (WNV), Japanese encephalitis virus (JEV) has a history of intercontinental spread, and birds are important for the maintenance and transmission of both of these closely related viruses. We examined viremic and serologic responses of blackbirds (Agelaius phoeniceus), with and without immunity to WNV, following experimental inoculation with two strains of JEV. Japanese encephalitis (JE) viremia was detected in only one of 16 (6.3%) WNV-immune birds, while all 16 nonimmune birds had detectable JE viremia. Two weeks after JEV inoculation, all birds without pre-existing WNV immunity had clearly distinguishable anti-JEV antibodies, while in all birds with pre-existing WNV immunity, antibodies to WNV and JEV were either indistinguishable or the anti-WNV antibody titers were significantly higher. As WNV is endemic throughout much of North America, WNV immunity among birds may dampen transmission while complicating the serologic diagnosis of JEV, should this pathogen be introduced to North America. PMID:19848083

  6. Differential Diagnosis of Japanese Encephalitis Virus Infections with the Inbios JE Detect™ and DEN Detect™ MAC-ELISA Kits.

    PubMed

    Johnson, Barbara W; Goodman, Christin H; Jee, Youngmee; Featherstone, David A

    2016-04-01

    Japanese encephalitis virus (JEV) is the leading cause of pediatric viral neurological disease in Asia. The JEV-specific IgM antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA) in cerebrospinal fluid (CSF) and serum is the recommended method of laboratory diagnosis, but specificity of JEV MAC-ELISA can be low due to cross-reactivity. To increase the specificity of the commercially available JEDetect™ MAC-ELISA (JEDetect), a differential testing algorithm was developed in which samples tested by JEDetect with positive results were subsequently tested by the DENDetect™ MAC-ELISA (DENDetect) kit, and results of both tests were used to make the final interpretation. The testing algorithm was evaluated with a reference panel of serum and CSF samples submitted for confirmatory testing. In serum, the false Japanese encephalitis (JE) positive rate was reduced, but sequential testing in CSF resulted in reduced JE specificity, as true JEV+ CSF samples had positive results by both JEDetect and DENDetect and were classified as JE- (dengue virus [DENV]+). Differential diagnosis of JE by sequential testing with JEDetect and DENDetect increased specificity for JE in serum, but more data with CSF is needed to make a final determination on the usefulness of this testing algorithm for CSF. PMID:26856911

  7. Differential Diagnosis of Japanese Encephalitis Virus Infections with the Inbios JE Detect™ and DEN Detect™ MAC-ELISA Kits

    PubMed Central

    Johnson, Barbara W.; Goodman, Christin H.; Jee, Youngmee; Featherstone, David A.

    2016-01-01

    Japanese encephalitis virus (JEV) is the leading cause of pediatric viral neurological disease in Asia. The JEV-specific IgM antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA) in cerebrospinal fluid (CSF) and serum is the recommended method of laboratory diagnosis, but specificity of JEV MAC-ELISA can be low due to cross-reactivity. To increase the specificity of the commercially available JE Detect™ MAC-ELISA (JE Detect), a differential testing algorithm was developed in which samples tested by JE Detect with positive results were subsequently tested by the DEN Detect™ MAC-ELISA (DEN Detect) kit, and results of both tests were used to make the final interpretation. The testing algorithm was evaluated with a reference panel of serum and CSF samples submitted for confirmatory testing. In serum, the false Japanese encephalitis (JE) positive rate was reduced, but sequential testing in CSF resulted in reduced JE specificity, as true JEV+ CSF samples had positive results by both JE Detect and DEN Detect and were classified as JE− (dengue virus [DENV]+). Differential diagnosis of JE by sequential testing with JE Detect and DEN Detect increased specificity for JE in serum, but more data with CSF is needed to make a final determination on the usefulness of this testing algorithm for CSF. PMID:26856911

  8. Japanese Encephalitis Complicated with Obstructive Hydrocephalus

    PubMed Central

    Suman, Vivek; Panwar, Ajay; Raizada, Alpana

    2016-01-01

    Japanese Encephalitis (JE), caused by Japanese encephalitis virus (JEV), a flavi-virus, is the most significant aetiology of arboviral encephalitis worldwide. It has resulted in epidemics of encephalitis in the Indian subcontinent. Here, we report a case of 36-year-old female who presented with a short history of fever and headache followed by altered sensorium. Funduscopic examination revealed Papilloedema. Pyogenic or viral meningoencephalitis along with complicated malaria were kept as initial differential diagnosis. Magnetic Resonance Imaging (MRI) of brain revealed involvement of posterior limb of internal capsule and bilateral thalami in the form of haemorrhagic encephalitis along with obstructive hydrocephalus. Cerebro Spinal Fluid (CSF) serology (IgM ELISA) showed JE as the causative agent. Despite extensive literature search, we could not find a case of JE reported with hydrocephalus as a complication. This case highlights the typical and atypical features of JE including imaging findings and exemplifies the way, how diversely JE can present and would thus help in preparing management paradigms accordingly. PMID:27042509

  9. Japanese Encephalitis Complicated with Obstructive Hydrocephalus.

    PubMed

    Suman, Vivek; Roy, Ujjawal; Panwar, Ajay; Raizada, Alpana

    2016-02-01

    Japanese Encephalitis (JE), caused by Japanese encephalitis virus (JEV), a flavi-virus, is the most significant aetiology of arboviral encephalitis worldwide. It has resulted in epidemics of encephalitis in the Indian subcontinent. Here, we report a case of 36-year-old female who presented with a short history of fever and headache followed by altered sensorium. Funduscopic examination revealed Papilloedema. Pyogenic or viral meningoencephalitis along with complicated malaria were kept as initial differential diagnosis. Magnetic Resonance Imaging (MRI) of brain revealed involvement of posterior limb of internal capsule and bilateral thalami in the form of haemorrhagic encephalitis along with obstructive hydrocephalus. Cerebro Spinal Fluid (CSF) serology (IgM ELISA) showed JE as the causative agent. Despite extensive literature search, we could not find a case of JE reported with hydrocephalus as a complication. This case highlights the typical and atypical features of JE including imaging findings and exemplifies the way, how diversely JE can present and would thus help in preparing management paradigms accordingly. PMID:27042509

  10. Pathogenic and Genotypic Characterization of a Japanese Encephalitis Virus Isolate Associated with Reproductive Failure in an Indian Pig Herd

    PubMed Central

    Desingu, P. A.; Ray, Pradeep K.; Patel, B. H. M.; Singh, R.; Singh, R. K.; Saikumar, G

    2016-01-01

    Background India is endemic to Japanese encephalitis virus (JEV) and recurrent outbreaks occur mainly in rice growing areas. Pigs are considered to be the amplifying host for JEV and infection in gestating pigs results in reproductive failure. Most studies conducted on JEV infection in Indian pigs have been serological surveys and very little is known about JEV genotypes circulating in pigs. So the potential risk posed by pigs in JEV transmission and the genetic relationship between viruses circulating in pigs, mosquitoes and humans is poorly understood. Methodology/Principal Findings This study was conducted in pigs with a history of reproductive failure characterized by stillborn piglets with neuropathological lesions. Japanese encephalitis (JE) suspected brain specimens inoculated intracerebrally into mice and Vero cells resulted in successful isolation of JEV/SW/IVRI/395A/2014. Clinicopathological observations in infected mice, demonstration of JEV antigen in brain, and analysis of the envelope protein identified the swine isolate as being neurovirulent. Phylogenetic analysis based on prM and E gene sequences showed that it belonged to genotype III. This swine isolate was closely related to JEV associated with the 2005 outbreak in India and JaoArS982 from Japan. Phylogenetic analysis of JEV strains collected between 1956 and 2014 in India categorized the GIII viruses into different clades blurring their spatial distribution, which has been discernible in the previous century. Conclusions/Significance Isolation of JEV from stillborn piglets and its close genetic relationship with viruses detected at least three decades ago in humans and mosquitoes in Japan suggests that the virus may have been circulating among Indian pigs for several decades. The close similarity between the present swine isolate and those detected in humans affected in the 2005 outbreak in Uttar Pradesh, India, suggests the need for more intensive surveillance of pigs and implementation of

  11. Safety and immunogenicity of a delta inulin-adjuvanted inactivated Japanese encephalitis virus vaccine in pregnant mares and foals.

    PubMed

    Bielefeldt-Ohmann, Helle; Prow, Natalie A; Wang, Wenqi; Tan, Cindy S E; Coyle, Mitchell; Douma, Alysha; Hobson-Peters, Jody; Kidd, Lisa; Hall, Roy A; Petrovsky, Nikolai

    2014-01-01

    In 2011, following severe flooding in Eastern Australia, an unprecedented epidemic of equine encephalitis occurred in South-Eastern Australia, caused by Murray Valley encephalitis virus (MVEV) and a new variant strain of Kunjin virus, a subtype of West Nile virus (WNVKUN). This prompted us to assess whether a delta inulin-adjuvanted, inactivated cell culture-derived Japanese encephalitis virus (JEV) vaccine (JE-ADVAX™) could be used in horses, including pregnant mares and foals, to not only induce immunity to JEV, but also elicit cross-protective antibodies against MVEV and WNVKUN. Foals, 74-152 days old, received two injections of JE-ADVAX™. The vaccine was safe and well-tolerated and induced a strong JEV-neutralizing antibody response in all foals. MVEV and WNVKUN antibody cross-reactivity was seen in 33% and 42% of the immunized foals, respectively. JE-ADVAX™ was also safe and well-tolerated in pregnant mares and induced high JEV-neutralizing titers. The neutralizing activity was passively transferred to their foals via colostrum. Foals that acquired passive immunity to JEV via maternal antibodies then were immunized with JE-ADVAX™ at 36-83 days of age, showed evidence of maternal antibody interference with low peak antibody titers post-immunization when compared to immunized foals of JEV-naïve dams. Nevertheless, when given a single JE-ADVAX™ booster immunization as yearlings, these animals developed a rapid and robust JEV-neutralizing antibody response, indicating that they were successfully primed to JEV when immunized as foals, despite the presence of maternal antibodies. Overall, JE-ADVAX™ appears safe and well-tolerated in pregnant mares and young foals and induces protective levels of JEV neutralizing antibodies with partial cross-neutralization of MVEV and WNVKUN. PMID:25516480

  12. Griffithsin binds to the glycosylated proteins (E and prM) of Japanese encephalitis virus and inhibit its infection.

    PubMed

    Ishag, Hassan Z A; Li, Chen; Wang, Fengjuan; Mao, Xiang

    2016-04-01

    Griffithsin (GRFT) is a broad-spectrum antiviral protein against several glycosylated viruses. In our previous publication, we have shown that GRFT exerted antiviral activity against Japanese encephalitis virus (JEV) infection. Herein, we further elucidated the mechanism by which GRFT inhibits JEV infection in BHK-21 cells. In vitro experiments using Pull-down assay and Co-immunoprecipitation (CO-IP) assay showed that GRFT binds to the JEV glycosylated viral proteins, specifically the enveloped (E) and premature (prM) glycoproteins. The binding of GRFT to the JEV was competitively inhibited by increasing concentrations of mannose; in turns abolished anti-JEV activity of GRFT. We suggested that, the binding of GRFT to the glycosylated viral proteins may contribute to its anti-JEV activity. Collectively, our data indicated a possible mechanism by which GRFT exerted its anti-JEV activity. This observation suggests GRFT's potentials in the development of therapeutics against JEV or other flavivirus infection. PMID:26820432

  13. Simultaneous detection of West Nile and Japanese encephalitis virus RNA by duplex TaqMan RT-PCR.

    PubMed

    Barros, Silvia C; Ramos, Fernanda; Zé-Zé, Líbia; Alves, Maria J; Fagulha, Teresa; Duarte, Margarida; Henriques, Margarida; Luís, Tiago; Fevereiro, Miguel

    2013-11-01

    West Nile virus (WNV) and Japanese encephalitis virus (JEV) are important mosquito-borne viruses of the Flaviviridae family, associated with encephalitis, mainly in humans and horses. WNV is also pathogen for many bird species. The incidence of human and animal WNV infections in Europe has risen, mostly in recent years, and JEV was detected in 2011 in mosquitoes collected in Italy and may emerge in Europe in the same way as other flaviviruses had emerged recently (USUTU and Bagaza virus) and should be regarded as a potential threat to public health. Prompt identification and discrimination between WNV and JEV provides critical epidemiological data for prevalence studies and public and animal health management policies. Here we describe a quantitative one-step duplex TaqMan RT-PCR, targeting non-structural protein 2A gene (NS2A-qRT-PCR), based on only one primer pair and two probes for differential diagnosis of WNV and JEV. Also this assay enables the detection of both WNV lineages (WNV-1 and WNV-2). To access the specificity of NS2A-qRT-PCR a panel of different arboviruses were used. The assay was shown to be specific for both WNV lineages (WNV-1 and WNV-2), WNV related Kunjin virus and JEV, since no cross-reactions were observed with other tested arboviruses. Sensitivity of the assay was determined using serial dilutions of in vitro-transcribed RNA from WNV and JEV. The duplex NS2A-qRT-PCR assay was shown to be very sensitive, being able to detect 10 copies of WNV and JEV RNA. This assay is a suitable tool for the diagnosis of WNV and JEV, and provides a valuable addition to the methods currently available for routine diagnosis of these zoonoses and for surveillance studies. PMID:23892127

  14. Immunogenicity and protective efficacy of the E. coli-expressed domain III of Japanese encephalitis virus envelope protein in mice.

    PubMed

    Alka; Bharati, Kaushik; Malik, Y P S; Vrati, Sudhanshu

    2007-12-01

    Domain III of Japanese encephalitis virus (JEV) envelope protein (E-DIII) was synthesized in E. coli as a fusion protein containing maltose-binding protein (MBP-E-DIII) or six contiguous histidine residues (His-E-DIII) at its N-terminus. MBP-E-DIII was found both in the soluble as well as the insoluble fraction of the bacterial lysate, while His-E-DIII was found exclusively in the inclusion bodies. These purified proteins were examined in mice for their immunogenicity in presence of an aluminium hydroxide based-adjuvant Alhydrogel and Freund's adjuvant. While both proteins generated anti-JEV antibodies that neutralized JEV activity in vitro, His-E-DIII generated higher antibody titers than MBP-E-DIII. Mice immunized with His-E-DIII in presence of Alhydrogel generated antibody titers similar to those induced by the commercial vaccine and protected mice against lethal JEV challenge. PMID:17377815

  15. Adaptation of BHK-21 Cells to Growth in Shaker Culture and Subsequent Challenge by Japanese Encephalitis Virus

    PubMed Central

    Guskey, Louis E.; Jenkin, Howard M.

    1975-01-01

    Baby hamster kidney (BHK-21) cells were adapted to grow in shaker culture using Waymouth medium 752/1 containing 20 mM N-2-hydroxyethyl-piperazine-N′-2′-ethanesulfonic acid buffer and supplemented with 2.5% (vol/vol) calf serum, 0.002% (wt/vol) sodium oleate, and 0.2% fatty acid-free bovine serum albumin (WO2.5). Infectivity of Japanese encephalitis virus grown in the cells adapted to WO2.5 approached 2 × 108 plaque-forming units per ml. The culture volume of infected cells was reduced fivefold 12 h after infection. This step resulted in a 10-fold increase in infectivity over that obtained from infected cultures not subjected to volume reduction. PMID:1237269

  16. Adaptation of BHK-21 cells to growth in shaker culture and subsequent challenge by Japanese encephalitis virus.

    PubMed

    Guskey, L E; Jenkin, H M

    1975-09-01

    Baby hamster kidney (BHK-21) cells were adapted to grow in shaker culture using Waymouth medium 752/1 containing 20 mM N-2-hydroxyethyl-piperazine-N'-2'-ethanesulfonic acid buffer and supplemented with 2.5% (vol/vol) calf serum, 0.002% (wt/vol) sodium oleate, and 0.2% fatty acid-free bovine serum albumin (WO2.5). Infectivity of Japanese encephalitis virus grown in the cells adapted to WO2.5 approached 2 x 10(8) plaque-forming units per ml. The culture volume of infected cells was reduced fivefold 12 h after infection. This step resulted in a 10-fold increase in infectivity over that obtained from infected cultures not subjected to volume reduction. PMID:1237269

  17. Dynamics of the Emergence and Establishment of a Newly Dominant Genotype of Japanese Encephalitis Virus throughout Asia

    PubMed Central

    Schuh, Amy J.; Ward, Melissa J.; Leigh Brown, Andrew J.

    2014-01-01

    ABSTRACT In recent years, genotype I (GI) of Japanese encephalitis virus (JEV) has displaced genotype III (GIII) as the dominant virus genotype throughout Asia. In this study, the largest collection of GIII and GI envelope gene-derived viral sequences assembled to date was used to reconstruct the spatiotemporal chronology of genotype displacement throughout Asia and to determine the evolutionary and epidemiological dynamics underlying this significant event. GI consists of two clades, GI-a and GI-b, with the latter being associated with displacement of GIII as the dominant JEV genotype throughout Asia in the 1990s. Phylogeographic analysis indicated that GI-a diverged in Thailand or Cambodia and has remained confined to tropical Asia, whereas GI-b diverged in Vietnam and then dispersed northwards to China, where it was subsequently dispersed to Japan, Korea, and Taiwan. Molecular adaptation was detected by more than one method at one site (residue 15), and coevolution was detected at two pairs of sites (residues 89 to 360 and 129 to 141) within the GI E gene protein alignment. Viral multiplication and temperature sensitivity analyses in avian and mosquito cells revealed that the GI-b isolate JE-91 had significantly higher infectivity titers in mosquito cells from 24 to 48 h postinfection than did the GI-a and GIII isolates. If the JE-91 isolate is indeed representative of GI-b, an increased multiplicative ability of GI-b viruses compared to that of GIII viruses early in mosquito infection may have resulted in a shortened extrinsic incubation period that led to an increased number of GI enzootic transmission cycles and the subsequent displacement of GIII. IMPORTANCE Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, represents the most significant etiology of childhood viral neurological infection in Asia. Despite the existence of effective vaccines, JEV is responsible for an estimated 68,000 human cases and a reported 10,000 to 15,000 deaths annually

  18. Type-I interferon response affects an inoculation dose-independent mortality in mice following Japanese encephalitis virus infection

    PubMed Central

    2014-01-01

    Background The laboratory mouse model is commonly employed to study the pathogenesis of encephalitic flaviviruses such as Japanese encephalitis virus (JEV). However, it is known that some strains of these viruses do not elicit a typical mortality dose response curve from this organism after peripheral infection and the reason for it has not yet been fully understood. It is suggested that induction of more vigorous Type-I IFN (IFN-I) response might control early virus dissemination following increasing infectious challenge doses of the virus. Thus, the objective of this study was to examine this suggested role of IFN-I in the mortality of mice infected with various doses of JEV. Methods Inbred 129 mice and their IFNAR KO (A129) mice were subcutaneously inoculated with 100, 102, 104 or 106 pfu of JaOArS982 strain of JEV. Mice were weighed daily and observed for clinical signs. Virus titers in the brains and spleens of JEV-infected mice were determined by plaque forming assays. The upregulated mRNA levels of genes related to IFN-I response of mice were examined by real-time PCR. Results The mortality rates of 129 mice infected with JaOArS982 did not significantly increase despite the increase in inoculation dose and no significant difference of viral loads was observed between their brains. However, there was clear elevation of the mRNA levels of interferon regulatory factor (IRF)3, IRF7, IRF9, MDA5 and RIG-I at 24 hours post-infection depending on the inoculation dose. In A129 mice, length of survival days and the viral loads of spleen and brain were observed to be inoculation dose-dependent. Conclusions From these results, it is suggested that early IFN-I response elicited by high inoculation doses of JEV provides an anti-viral effect during the early phase of infection. Accordingly, virus replication is counteracted by IFN-I response at each increasing inoculation dose resulting in the interference of impending severe disease course or fatal outcome; hence, this

  19. An approach for differentiating echovirus 30 and Japanese encephalitis virus infections in acute meningitis/encephalitis: a retrospective study of 103 cases in Vietnam

    PubMed Central

    2013-01-01

    Background In recent decades, Echovirus 30 (E30) and Japanese encephalitis virus (JEV) have been reported to be the common causative agents of acute meningitis among patients in South East Asia. An E30 outbreak in Vietnam in 2001–2002 gained our interest because the initial clinical diagnosis of infected patients was due to JEV infection. There are few clinical insights regarding E30 cases, and there are no reports comparing E30 and JEV acute meningitis/encephalitis cases based on clinical symptoms and case histories. We therefore aimed to identify reliable clinical methods to differentiate E30 and JEV acute meningitis/encephalitis. Methods A retrospective, cross-sectional study was conducted to compare E30 and JEV acute meningitis/encephalitis cases. We collected and analyzed the clinical records of 43 E30 confirmed cases (E30 group) and 60 JEV confirmed cases (JEV group). Clinical data were compared between the E30 and the JEV groups. Differences of clinical parameters were analyzed by certain statistical tests. Results Fever, headache, and vomiting were the most common symptoms in both the E30 and the JEV groups. Combined symptoms of headache and vomiting and the triad of symptoms of fever, headache, and vomiting were observed in more patients in the E30 group (E30 vs. JEV: 19% vs. 0%, p < 0.001; 74% vs. 27%, p < 0.001, respectively). On the other hand, strong neurological symptoms such as seizure (5% vs. 73%, p < 0.001) and altered consciousness (12% vs. 97%, p < 0.001) were manifested primarily in the JEV group. CSF leukocytosis was observed predominantly in the E30 group (80 vs. 18 cells/μL, p = 0.003), whereas decreasing CSF sugar level was observed predominantly in the JEV group (58.7 vs. 46.9 mg/dL, p < 0.001). Conclusion Fever, headache, vomiting, absence of neurological symptoms (seizure, altered consciousness), and presence of CSF leukocytosis are important parameters to consider in differentiating E30 from JEV cases during

  20. Tissue tropism and molecular characterization of a Japanese encephalitis virus strain isolated from pigs in southwest China.

    PubMed

    Yuan, Lei; Wu, Rui; Liu, Hanyang; Wen, Xintian; Huang, Xiaobo; Wen, Yiping; Ma, Xiaoping; Yan, Qigui; Huang, Yong; Zhao, Qin; Cao, Sanjie

    2016-04-01

    Since September 2012, an epidemic has been spreading among swine in a pig farm located in Sichuan province, southwest China, which has resulted in abortion, stillbirth, and fetal mummification. The brains of stillborn pigs were collected and a previously unknown Japanese encephalitis virus (JEV), namely SCYA201201, was isolated. According to the results of agarose gel diffusion precipitation, indirect immunofluorescence analysis, neutralization testing, reverse transcription PCR (RT-PCR) amplification, and physical and chemical testing, the virus was conformed to have the characteristics of JEV. The virus titer in BHK-21 cells was 10(8.47)PFU/ml and the median lethal dose (LD50) to 3-week-old and 7-day-old mice was 1.99 log10 and 1.02 log10 PFU/LD50, respectively. The results of tissue tropism for mice showed that the viral load in the brain was significantly higher than other organs, indicating that the isolate was strongly neurotropic. Additionally, the complete genome sequence of the isolate was determined and compared with other JEV strains. Phylogenetic analysis showed that the isolate belongs to genotype I and may be an imported virus. The isolate had 88.4% nucleotide identity with the Chinese vaccine strain SA14-14-2. However, there were 69 amino acid substitutions compared with the strain SA14-14-2. Some substitutions indicated that SCYA201201 was highly neurovirulent and infective, in accordance with the results of animal testing. PMID:26851509

  1. Japanese Encephalitis Virus exploits the microRNA-432 to regulate the expression of Suppressor of Cytokine Signaling (SOCS) 5.

    PubMed

    Sharma, Nikhil; Kumawat, Kanhaiya L; Rastogi, Meghana; Basu, Anirban; Singh, Sunit K

    2016-01-01

    Japanese encephalitis virus (JEV) is a plus strand RNA virus, which infects brain. MicroRNAs are regulatory non-coding RNAs which regulate the expression of various genes in cells. Viruses modulate the expression of various microRNAs to suppress anti-viral signaling and evade the immune response. SOCS (Suppressor of cytokine signalling) family of proteins are negative regulators of anti-viral Jak-STAT pathway. In this study, we demonstrated the regulatory role of SOCS5 in Jak-STAT signaling and its exploitation by JEV through a microRNA mediated mechanism. JEV infection in human brain microglial cells (CHME3) downregulated the expression of miR-432, and upregulated SOCS5 levels. SOCS5 was validated as a target of miR-432 by using 3'UTR clone of SOCS5 in luciferase vector along with miR-432 mimic. The overexpression of miR-432 prior to JEV infection enhanced the phosphorylation of STAT1 resulting into increased ISRE activity and cellular inflammatory response resulting into diminished viral replication. The knockdown of SOCS5 resulted into increased STAT1 phosphorylation and suppressed viral replication. JEV infection mediated downregulation of miR-432 leads to SOCS5 upregulation, which helps the virus to evade cellular anti-viral response. This study demonstrated that JEV utilizes this microRNA mediated strategy to manipulate cellular immune response promoting JEV pathogenesis. PMID:27282499

  2. Japanese Encephalitis Virus exploits the microRNA-432 to regulate the expression of Suppressor of Cytokine Signaling (SOCS) 5

    PubMed Central

    Sharma, Nikhil; Kumawat, Kanhaiya L.; Rastogi, Meghana; Basu, Anirban; Singh, Sunit K.

    2016-01-01

    Japanese encephalitis virus (JEV) is a plus strand RNA virus, which infects brain. MicroRNAs are regulatory non-coding RNAs which regulate the expression of various genes in cells. Viruses modulate the expression of various microRNAs to suppress anti-viral signaling and evade the immune response. SOCS (Suppressor of cytokine signalling) family of proteins are negative regulators of anti-viral Jak-STAT pathway. In this study, we demonstrated the regulatory role of SOCS5 in Jak-STAT signaling and its exploitation by JEV through a microRNA mediated mechanism. JEV infection in human brain microglial cells (CHME3) downregulated the expression of miR-432, and upregulated SOCS5 levels. SOCS5 was validated as a target of miR-432 by using 3′UTR clone of SOCS5 in luciferase vector along with miR-432 mimic. The overexpression of miR-432 prior to JEV infection enhanced the phosphorylation of STAT1 resulting into increased ISRE activity and cellular inflammatory response resulting into diminished viral replication. The knockdown of SOCS5 resulted into increased STAT1 phosphorylation and suppressed viral replication. JEV infection mediated downregulation of miR-432 leads to SOCS5 upregulation, which helps the virus to evade cellular anti-viral response. This study demonstrated that JEV utilizes this microRNA mediated strategy to manipulate cellular immune response promoting JEV pathogenesis. PMID:27282499

  3. Sampling Design Influences the Observed Dominance of Culex tritaeniorhynchus: Considerations for Future Studies of Japanese Encephalitis Virus Transmission.

    PubMed

    Lord, Jennifer S; Al-Amin, Hasan Mohammad; Chakma, Sumit; Alam, Mohammad Shafiul; Gurley, Emily S; Pulliam, Juliet R C

    2016-01-01

    Mosquito sampling during Japanese encephalitis virus (JEV)-associated studies, particularly in India, has usually been conducted via aspirators or light traps to catch mosquitoes around cattle, which are dead-end hosts for JEV. High numbers of Culex tritaeniorhynchus, relative to other species, have often been caught during these studies. Less frequently, studies have involved sampling outdoor resting mosquitoes. We aimed to compare the relative abundance of mosquito species between these two previously used mosquito sampling methods. From September to December 2013 entomological surveys were undertaken in eight villages in a Japanese encephalitis (JE) endemic area of Bangladesh. Light traps were used to collect active mosquitoes in households, and resting boxes and a Bina Pani Das hop cage were used near oviposition sites to collect resting mosquitoes. Numbers of humans and domestic animals present in households where light traps were set were recorded. In five villages Cx. tritaeniorhynchus was more likely to be selected from light trap samples near hosts than resting collection samples near oviposition sites, according to log odds ratio tests. The opposite was true for Cx. pseudovishnui and Armigeres subalbatus, which can also transmit JEV. Culex tritaeniorhynchus constituted 59% of the mosquitoes sampled from households with cattle, 28% from households without cattle and 17% in resting collections. In contrast Cx. pseudovishnui constituted 5.4% of the sample from households with cattle, 16% from households with no cattle and 27% from resting collections, while Ar. subalbatus constituted 0.15%, 0.38%, and 8.4% of these samples respectively. These observations may be due to differences in timing of biting activity, host preference and host-seeking strategy rather than differences in population density. We suggest that future studies aiming to implicate vector species in transmission of JEV should consider focusing catches around hosts able to transmit JEV. PMID

  4. Sampling Design Influences the Observed Dominance of Culex tritaeniorhynchus: Considerations for Future Studies of Japanese Encephalitis Virus Transmission

    PubMed Central

    Lord, Jennifer S.; Al-Amin, Hasan Mohammad; Chakma, Sumit; Alam, Mohammad Shafiul; Gurley, Emily S.; Pulliam, Juliet R. C.

    2016-01-01

    Mosquito sampling during Japanese encephalitis virus (JEV)-associated studies, particularly in India, has usually been conducted via aspirators or light traps to catch mosquitoes around cattle, which are dead-end hosts for JEV. High numbers of Culex tritaeniorhynchus, relative to other species, have often been caught during these studies. Less frequently, studies have involved sampling outdoor resting mosquitoes. We aimed to compare the relative abundance of mosquito species between these two previously used mosquito sampling methods. From September to December 2013 entomological surveys were undertaken in eight villages in a Japanese encephalitis (JE) endemic area of Bangladesh. Light traps were used to collect active mosquitoes in households, and resting boxes and a Bina Pani Das hop cage were used near oviposition sites to collect resting mosquitoes. Numbers of humans and domestic animals present in households where light traps were set were recorded. In five villages Cx. tritaeniorhynchus was more likely to be selected from light trap samples near hosts than resting collection samples near oviposition sites, according to log odds ratio tests. The opposite was true for Cx. pseudovishnui and Armigeres subalbatus, which can also transmit JEV. Culex tritaeniorhynchus constituted 59% of the mosquitoes sampled from households with cattle, 28% from households without cattle and 17% in resting collections. In contrast Cx. pseudovishnui constituted 5.4% of the sample from households with cattle, 16% from households with no cattle and 27% from resting collections, while Ar. subalbatus constituted 0.15%, 0.38%, and 8.4% of these samples respectively. These observations may be due to differences in timing of biting activity, host preference and host-seeking strategy rather than differences in population density. We suggest that future studies aiming to implicate vector species in transmission of JEV should consider focusing catches around hosts able to transmit JEV. PMID

  5. MicroRNA-19b-3p Modulates Japanese Encephalitis Virus-Mediated Inflammation via Targeting RNF11

    PubMed Central

    Ashraf, Usama; Zhu, Bibo; Ye, Jing; Wan, Shengfeng; Nie, Yanru; Chen, Zheng; Cui, Min; Wang, Chong; Duan, Xiaodong; Zhang, Hao; Chen, Huanchun

    2016-01-01

    ABSTRACT Japanese encephalitis virus (JEV) can invade the central nervous system and consequently induce neuroinflammation, which is characterized by profound neuronal cell damage accompanied by astrogliosis and microgliosis. Albeit microRNAs (miRNAs) have emerged as major regulatory noncoding RNAs with profound effects on inflammatory response, it is unknown how astrocytic miRNAs regulate JEV-induced inflammation. Here, we found the involvement of miR-19b-3p in regulating the JEV-induced inflammatory response in vitro and in vivo. The data demonstrated that miR-19b-3p is upregulated in cultured cells and mouse brain tissues during JEV infection. Overexpression of miR-19b-3p led to increased production of inflammatory cytokines, including tumor necrosis factor alpha, interleukin-6, interleukin-1β, and chemokine (C-C motif) ligand 5, after JEV infection, whereas knockdown of miR-19b-3p had completely opposite effects. Mechanistically, miR-19b-3p modulated the JEV-induced inflammatory response via targeting ring finger protein 11, a negative regulator of nuclear factor kappa B signaling. We also found that inhibition of ring finger protein 11 by miR-19b-3p resulted in accumulation of nuclear factor kappa B in the nucleus, which in turn led to higher production of inflammatory cytokines. In vivo silencing of miR-19b-3p by a specific antagomir reinvigorates the expression level of RNF11, which in turn reduces the production of inflammatory cytokines, abrogates gliosis and neuronal cell death, and eventually improves the survival rate in the mouse model. Collectively, our results demonstrate that miR-19b-3p positively regulates the JEV-induced inflammatory response. Thus, miR-19b-3p targeting may constitute a thought-provoking approach to rein in JEV-induced inflammation. IMPORTANCE Japanese encephalitis virus (JEV) is one of the major causes of acute encephalitis in humans worldwide. The pathological features of JEV-induced encephalitis are inflammatory reactions and

  6. Protective immunity to Japanese encephalitis virus associated with anti-NS1 antibodies in a mouse model

    PubMed Central

    2012-01-01

    Background Japanese encephalitis virus (JEV) is a major mosquito-borne pathogen that causes viral encephalitis throughout Asia. Vaccination with an inactive JEV particle or attenuated virus is an efficient preventative measure for controlling infection. Flavivirus NS1 protein is a glycoprotein secreted during viral replication that plays multiple roles in the viral life cycle and pathogenesis. Utilizing JEV NS1 as an antigen in viral vectors induces a limited protective immune response against infection. Previous studies using E. coli-expressed JEV NS1 to immunize mice induced protection against lethal challenge; however, the protection mechanism through cellular and humoral immune responses was not described. Results JEV NS1 was expressed in and purified from Drosophila S2 cells in a native glycosylated multimeric form, which induced T-cell and antibody responses in immunized C3H/HeN mice. Mice vaccinated with 1 μg NS1 with or without water-in-oil adjuvant were partially protected against viral challenge and higher protection was observed in mice with higher antibody titers. IgG1 was preferentially elicited by an adjuvanted NS1 protein, whereas a larger load of IFN-γ was produced in splenocytes from mice immunized with aqueous NS1. Mice that passively received anti-NS1 mouse polyclonal immune sera were protected, and this phenomenon was dose-dependent, whereas protection was low or delayed after the passive transfer of anti-NS1 MAbs. Conclusion The purified NS1 subunit induced protective immunity in relation with anti-NS1 IgG1 antibodies. NS1 protein efficiently stimulated Th1-cell proliferation and IFN-γ production. Protection against lethal challenge was elicited by passive transfer of anti-NS1 antisera, suggesting that anti-NS1 antibodies play a substantial role in anti-viral immunity PMID:22828206

  7. Development of electrochemical immunosensors based on different serum antibody immobilization methods for detection of Japanese encephalitis virus

    NASA Astrophysics Data System (ADS)

    Tran, Quang Huy; Hanh Nguyen, Thi Hong; Mai, Anh Tuan; Thuy Nguyen, Thi; Khue Vu, Quang; Nga Phan, Thi

    2012-03-01

    This paper describes the development of electrochemical immunosensors based on human serum antibodies with different immobilization methods for detection of Japanese encephalitis virus (JEV). Human serum containing anti-JEV antibodies was used to immobilize onto the surface of silanized interdigitated electrodes by four methods: direct adsorption (APTES-serum), covalent binding with a cross linker of glutaraldehyde (APTES-GA-serum), covalent binding with a cross linker of glutaraldehyde combined with anti-human IgG (APTES-GA-anti-HIgG-serum) and covalent binding with a cross linker of glutaraldehyde combined with a bioaffinity of protein A (APTES-GA-PrA-serum). Atomic force microscopy was used to verify surface characteristics of the interdigitated electrodes before and after treatment with serum antibodies. The output signal of the immunosensors was measured by the change of conductivity resulting from the specific binding of JEV antigens and serum antibodies immobilized on the electrodes, with the help of horseradish peroxidase (HRP)-labeled secondary antibody against JEV. The results showed that the APTES-GA-PrA-serum method provided the highest signal of the electrochemical immunosensor for detection of JEV antigens, with the linear range from 25 ng ml‑1 to 1 μg ml‑1, and the limit of detection was about 10 ng ml‑1. This study shows a potential development of novel electrochemical immunosensors applied for virus detection in clinical samples in case of possible outbreaks.

  8. Japanese Encephalitis Virus Nonstructural Protein NS5 Interacts with Mitochondrial Trifunctional Protein and Impairs Fatty Acid β-Oxidation

    PubMed Central

    Kao, Yu-Ting; Chang, Bi-Lan; Liang, Jian-Jong; Tsai, Hang-Jen; Lee, Yi-Ling; Lin, Ren-Jye; Lin, Yi-Ling

    2015-01-01

    Infection with Japanese encephalitis virus (JEV) can induce the expression of pro-inflammatory cytokines and cause acute encephalitis in humans. β-oxidation breaks down fatty acids for ATP production in mitochondria, and impaired β-oxidation can induce pro-inflammatory cytokine expression. To address the role of fatty-acid β-oxidation in JEV infection, we measured the oxygen consumption rate of mock- and JEV-infected cells cultured with or without long chain fatty acid (LCFA) palmitate. Cells with JEV infection showed impaired LCFA β-oxidation and increased interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) expression. JEV nonstructural protein 5 (NS5) interacted with hydroxyacyl-CoA dehydrogenase α and β subunits, two components of the mitochondrial trifunctional protein (MTP) involved in LCFA β-oxidation, and NS5 proteins were detected in mitochondria and co-localized with MTP. LCFA β-oxidation was impaired and higher cytokines were induced in cells overexpressing NS5 protein as compared with control cells. Deletion and mutation studies showed that the N-terminus of NS5 was involved in the MTP association, and a single point mutation of NS5 residue 19 from methionine to alanine (NS5-M19A) reduced its binding ability with MTP. The recombinant JEV with NS5-M19A mutation (JEV-NS5-M19A) was less able to block LCFA β-oxidation and induced lower levels of IL-6 and TNF-α than wild-type JEV. Moreover, mice challenged with JEV-NS5-M19A showed less neurovirulence and neuroinvasiveness. We identified a novel function of JEV NS5 in viral pathogenesis by impairing LCFA β-oxidation and inducing cytokine expression by association with MTP. PMID:25816318

  9. Dynamics of Japanese Encephalitis Virus Transmission among Pigs in Northwest Bangladesh and the Potential Impact of Pig Vaccination

    PubMed Central

    Khan, Salah Uddin; Salje, Henrik; Hannan, A.; Islam, Md. Atiqul; Bhuyan, A. A. Mamun; Islam, Md. Ariful; Rahman, M. Ziaur; Nahar, Nazmun; Hossain, M. Jahangir; Luby, Stephen P.; Gurley, Emily S.

    2014-01-01

    Background Japanese encephalitis (JE) virus infection can cause severe disease in humans, resulting in death or permanent neurologic deficits among survivors. Studies indicate that the incidence of JE is high in northwestern Bangladesh. Pigs are amplifying hosts for JE virus (JEV) and a potentially important source of virus in the environment. The objectives of this study were to describe the transmission dynamics of JEV among pigs in northwestern Bangladesh and estimate the potential impact of vaccination to reduce incidence among pigs. Methodology/Principal Findings We conducted a comprehensive census of pigs in three JE endemic districts and tested a sample of them for evidence of previous JEV infection. We built a compartmental model to describe JEV transmission dynamics in this region and to estimate the potential impact of pig vaccination. We identified 11,364 pigs in the study area. Previous JEV infection was identified in 30% of pigs with no spatial differences in the proportion of pigs that were seropositive across the study area. We estimated that JEV infects 20% of susceptible pigs each year and the basic reproductive number among pigs was 1.2. The model suggest that vaccinating 50% of pigs each year resulted in an estimated 82% reduction in annual incidence in pigs. Conclusions/Significance The widespread distribution of historic JEV infection in pigs suggests they may play an important role in virus transmission in this area. Future studies are required to understand the contribution of pig infections to JE risk in humans and the potential impact of pig vaccination on human disease. PMID:25255286

  10. A novel dengue virus serotype 1 vaccine candidate based on Japanese encephalitis virus vaccine strain SA14-14-2 as the backbone.

    PubMed

    Yang, Huiqiang; Li, Zhushi; Lin, Hua; Wang, Wei; Yang, Jian; Liu, Lina; Zeng, Xianwu; Wu, Yonglin; Yu, Yongxin; Li, Yuhua

    2016-06-01

    To develop a potential dengue vaccine candidate, a full-length cDNA clone of a novel chimeric virus was constructed using recombinant DNA technology, with Japanese encephalitis virus (JEV) vaccine strain SA14-14-2 as the backbone, with its premembrane (prM) and envelope (E) genes substituted by their counterparts from dengue virus type 1 (DENV1). The chimeric virus (JEV/DENV1) was successfully recovered from primary hamster kidney (PHK) cells by transfection with the in vitro transcription products of JEV/DENV1 cDNA and was identified by complete genome sequencing and immunofluorescent staining. No neuroinvasiveness of this chimeric virus was observed in mice inoculated by the subcutaneous route (s.c.) or by the intraperitoneal route (i.p.), while some neurovirulence was displayed in mice that were inoculated directly by the intracerebral route (i.c.). The chimeric virus was able to stimulate high-titer production of antibodies against DENV1 and provided protection against lethal challenge with neuroadapted dengue virus in mice. These results suggest that the chimeric virus is a promising dengue vaccine candidate. PMID:26976137

  11. Development of a small animal peripheral challenge model of Japanese encephalitis virus using interferon deficient AG129 mice and the SA14-14-2 vaccine virus strain.

    PubMed

    Calvert, Amanda E; Dixon, Kandice L; Delorey, Mark J; Blair, Carol D; Roehrig, John T

    2014-01-01

    Japanese encephalitis virus (JEV) is the most common cause of viral encephalitis in Asia, and it is increasingly a global public health concern due to its recent geographic expansion. While commercial vaccines are available and used in some endemic countries, JEV continues to be a public health problem, with 50,000 cases reported annually. Research with virulent JEV in mouse models to develop new methods of prevention and treatment is restricted to BSL-3 containment facilities, confining these studies to investigators with access to these facilities. We have developed an adult small animal peripheral challenge model using interferon-deficient AG129 mice and the JEV live-attenuated vaccine SA14-14-2, thus requiring only BSL-2 containment. A low dose of virus (10PFU/0.1ml) induced 100% morbidity in infected mice. Increased body temperatures measured by implantable temperature transponders correlated with an increase in infectious virus and viral RNA in serum, spleen and brain as well as an increase in pro-inflammatory markers measured by a 58-biomarker multi-analyte profile (MAP) constructed during the course of infection. In the future, the MAP measurements can be used as a baseline for comparison in order to better assess the inhibition of disease progression by other prophylactic and therapeutic agents. The use of the AG129/JEV SA14-14-2 animal model makes vaccine and therapeutic studies feasible for laboratories with limited biocontainment facilities. PMID:24252694

  12. RNA-protein interactions: involvement of NS3, NS5, and 3' noncoding regions of Japanese encephalitis virus genomic RNA.

    PubMed Central

    Chen, C J; Kuo, M D; Chien, L J; Hsu, S L; Wang, Y M; Lin, J H

    1997-01-01

    The mechanism of replication of the flavivirus Japanese encephalitis virus (JEV) is not well known. The structures at the 3' end of the viral genome are highly conserved among divergent flaviviruses, suggesting that they may function as cis-acting signals for RNA replication and, as such, might specifically bind to cellular or viral proteins. UV cross-linking experiments were performed to identify the proteins that bind with the JEV plus-strand 3' noncoding region (NCR). Two proteins, p71 and p110, from JEV-infected but not from uninfected cell extracts were shown to bind specifically to the plus-strand 3' NCR. The quantities of these binding proteins increased during the course of JEV infection and correlated with the levels of JEV RNA synthesis in cell extracts. UV cross-linking coupled with Western blot and immunoprecipitation analysis showed that the p110 and p71 proteins were JEV NS5 and NS3, respectively, which are proposed as components of the RNA replicase. The putative stem-loop structure present within the plus-strand 3' NCR was required for the binding of these proteins. Furthermore, both proteins could interact with each other and form a protein-protein complex in vivo. These findings suggest that the 3' NCR of JEV genomic RNA may form a replication complex together with NS3 and NS5; this complex may be involved in JEV minus-strand RNA synthesis. PMID:9094618

  13. Induction of protective immunity in animals vaccinated with recombinant vaccinia viruses that express PreM and E glycoproteins of Japanese encephalitis virus.

    PubMed Central

    Yasuda, A; Kimura-Kuroda, J; Ogimoto, M; Miyamoto, M; Sata, T; Sato, T; Takamura, C; Kurata, T; Kojima, A; Yasui, K

    1990-01-01

    A cDNA clone representing the genome of structural proteins of Japanese encephalitis virus (JEV) was inserted into the thymidine kinase gene of vaccinia virus strains LC16mO and WR under the control of a strong early-late promoter for the vaccinia virus 7.5-kilodalton polypeptide. Indirect immunofluorescence and fluorescence-activated flow cytometric analysis revealed that the recombinant vaccinia viruses expressed JEV E protein on the membrane surface, as well as in the cytoplasm, of recombinant-infected cells. In addition, the E protein expressed from the JEV recombinants reacted to nine different characteristic monoclonal antibodies, some of which have hemagglutination-inhibiting and JEV-neutralizing activities. Radioimmunoprecipitation analysis demonstrated that two major proteins expressed in recombinant-infected cells were processed and glycosylated as the authentic PreM and E glycoproteins of JEV. Inoculation of rabbits with the infectious recombinant vaccinia virus resulted in rapid production of antiserum specific for the PreM and E glycoproteins of JEV. This antiserum had both hemagglutination-inhibiting and virus-neutralizing activities against JEV. Furthermore, mice vaccinated with the recombinant also produced JEV-neutralizing antibodies and were resistant to challenge with JEV. Images PMID:2159544

  14. Transcriptional regulation of miR-15b by c-Rel and CREB in Japanese encephalitis virus infection

    PubMed Central

    Zhu, Bibo; Ye, Jing; Ashraf, Usama; Li, Yunchuan; Chen, Huanchun; Song, Yunfeng; Cao, Shengbo

    2016-01-01

    MicroRNAs (miRNAs) have been well known to play diverse roles in viral infection at the level of posttranscriptional repression. However, much less is understood about the mechanism by which miRNAs are regulated during viral infection. It is likely that both host and virus contain factors to modulate miRNA expression. Here we report the up-regulation of microRNA-15b (miR-15b) in vitro upon infection with Japanese encephalitis virus (JEV). Analysis of miR-15b precursor, pri-miR-15b and pre-miR-15b, suggest that the regulation occurs transcriptionally. Further, we identified the transcriptional regulatory region of miR-15b that contains consensus binding motif for NF-κB subunit c-Rel and cAMP-response element binding protein (CREB), which are known as transcription factor to regulate gene expression. By promoter fusion and mutational analyses, we demonstrated that c-Rel and CREB bind directly to the promoter elements of miR-15b, which are responsible for miR-15b transcription in response to JEV infection. Finally, we showed that pharmacological inhibition of ERK and NF-κB signaling pathway blocked induction of miR-15b in JEV infection, suggesting important roles of ERK and NF-κB pathway in the regulation of miR-15b gene. Therefore, our observations indicate that induced expression of miR-15b is modulated by c-Rel and CREB in response to JEV infection. PMID:26931521

  15. Transcriptional regulation of miR-15b by c-Rel and CREB in Japanese encephalitis virus infection.

    PubMed

    Zhu, Bibo; Ye, Jing; Ashraf, Usama; Li, Yunchuan; Chen, Huanchun; Song, Yunfeng; Cao, Shengbo

    2016-01-01

    MicroRNAs (miRNAs) have been well known to play diverse roles in viral infection at the level of posttranscriptional repression. However, much less is understood about the mechanism by which miRNAs are regulated during viral infection. It is likely that both host and virus contain factors to modulate miRNA expression. Here we report the up-regulation of microRNA-15b (miR-15b) in vitro upon infection with Japanese encephalitis virus (JEV). Analysis of miR-15b precursor, pri-miR-15b and pre-miR-15b, suggest that the regulation occurs transcriptionally. Further, we identified the transcriptional regulatory region of miR-15b that contains consensus binding motif for NF-κB subunit c-Rel and cAMP-response element binding protein (CREB), which are known as transcription factor to regulate gene expression. By promoter fusion and mutational analyses, we demonstrated that c-Rel and CREB bind directly to the promoter elements of miR-15b, which are responsible for miR-15b transcription in response to JEV infection. Finally, we showed that pharmacological inhibition of ERK and NF-κB signaling pathway blocked induction of miR-15b in JEV infection, suggesting important roles of ERK and NF-κB pathway in the regulation of miR-15b gene. Therefore, our observations indicate that induced expression of miR-15b is modulated by c-Rel and CREB in response to JEV infection. PMID:26931521

  16. Antiviral Activity of a Novel Compound CW-33 against Japanese Encephalitis Virus through Inhibiting Intracellular Calcium Overload.

    PubMed

    Huang, Su-Hua; Lien, Jin-Cherng; Chen, Chao-Jung; Liu, Yu-Ching; Wang, Ching-Ying; Ping, Chia-Fong; Lin, Yu-Fong; Huang, An-Cheng; Lin, Cheng-Wen

    2016-01-01

    Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, has five genotypes (I, II, III, IV, and V). JEV genotype I circulates widely in some Asian countries. However, current JEV vaccines based on genotype III strains show low neutralizing capacities against genotype I variants. In addition, JE has no specific treatment, except a few supportive treatments. Compound CW-33, an intermediate synthesized derivative of furoquinolines, was investigated for its antiviral activities against JEV in this study. CW-33 exhibited the less cytotoxicity to Syrian baby hamster kidney (BHK-21) and human medulloblastoma (TE761) cells. CW-33 dose-dependently reduced the cytopathic effect and apoptosis of JEV-infected cells. Supernatant virus yield assay pinpointed CW-33 as having potential anti-JEV activity with IC50 values ranging from 12.7 to 38.5 μM. Time-of-addition assay with CW-33 indicated that simultaneous and post-treatment had no plaque reduction activity, but continuous and simultaneous treatments proved to have highly effective antiviral activity, with IC50 values of 32.7 and 48.5 μM, respectively. CW-33 significantly moderated JEV-triggered Ca(2+) overload, which correlated with the recovery of mitochondria membrane potential as well as the activation of Akt/mTOR and Jak/STAT1 signals in treated infected cells. Phosphopeptide profiling by LC-MS/MS revealed that CW-33 upregulated proteins from the enzyme modulator category, such as protein phosphatase inhibitor 2 (I-2), Rho GTPase-activating protein 35, ARF GTPase-activating protein GIT2, and putative 3-phosphoinositide-dependent protein kinase 2. These enzyme modulators identified were associated with the activation of Akt/mTOR and Jak/STAT1 signals. Meanwhile, I-2 treatment substantially inhibited the apoptosis of JEV-infected cells. The results demonstrated that CW-33 exhibited a significant potential in the development of anti-JEV agents. PMID:27563890

  17. Prevalence of Neutralizing Antibodies to Japanese Encephalitis Virus among High-Risk Age Groups in South Korea, 2010

    PubMed Central

    Ju, Young Ran; Han, Myung Guk; Lee, Won-Ja; Jeong, Young Eui

    2016-01-01

    After an extensive vaccination policy, Japanese encephalitis (JE) was nearly eliminated since the mid-1980s in South Korea. Vaccination in children shifted the affected age of JE patients from children to adults. However, an abrupt increase in JE cases occurred in 2010, and this trend has continued. The present study aimed to investigate the prevalence of neutralizing antibodies to the JE virus (JEV) among high-risk age groups (≥40 years) in South Korea. A plaque reduction neutralization test was conducted to evaluate the prevalence of neutralizing antibodies to JEV in 945 subjects within four age groups (30–39, 40–49, 50–59, and 60–69 years) in 10 provinces. Of the 945 enrolled subjects, 927 (98.1%) exhibited antibodies against JEV. No significant differences were found in the prevalence of neutralizing antibodies according to sex, age, or occupation. However, there were significant differences in the plaque reduction rate according to age and occupation; oldest age group had a higher reduction rate, and subjects who were employed in agriculture or forestry also had a higher value than the other occupations. We also found that three provinces (Gangwon, Jeonnam, and Gyeongnam) had a relatively lower plaque reduction rate than the other locations. In addition, enzyme-linked immunosorbent assays were conducted to determine recent viral infections and 12 (2.2%) subjects were found to have been recently infected by the virus. In conclusion, the present study clearly indicated that the prevalence of neutralizing antibodies has been maintained at very high levels among adult age groups owing to vaccination or natural infections, or both. In the future, serosurveillance should be conducted periodically using more representative samples to better understand the population-level immunity to JE in South Korea. PMID:26807709

  18. Evaluation of Extracellular Subviral Particles of Dengue Virus Type 2 and Japanese Encephalitis Virus Produced by Spodoptera frugiperda Cells for Use as Vaccine and Diagnostic Antigens ▿

    PubMed Central

    Kuwahara, Miwa; Konishi, Eiji

    2010-01-01

    New or improved vaccines against dengue virus types 1 to 4 (DENV1 to DENV4) and Japanese encephalitis virus (JEV), the causative agents of dengue fever and Japanese encephalitis (JE), respectively, are urgently required. The use of noninfectious subviral extracellular particles (EPs) is an inexpensive and safe strategy for the production of protein-based flavivirus vaccines. Although coexpression of premembrane (prM) and envelope (E) proteins has been demonstrated to produce EPs in mammalian cells, low yields have hindered their commercial application. Therefore, we used an insect cell expression system with Spodoptera frugiperda-derived Sf9 cells to investigate high-level production of DENV2 and JEV EPs. Sf9 cells transfected with the prM and E genes of DENV2 or JEV secreted corresponding viral antigens in a particulate form that were biochemically and biophysically equivalent to the authentic antigens obtained from infected C6/36 mosquito cells. Additionally, equivalent neutralizing antibody titers were induced in mice immunized either with EPs produced by transfected Sf9 cells or with EPs produced by transfected mammalian cells, in the context of coimmunization with a DNA vaccine that expresses EPs. Furthermore, the results of an enzyme-linked immunosorbent assay (ELISA) using an EP antigen derived from Sf9 cells correlated significantly with the results obtained by a neutralization test and an ELISA using an EP antigen derived from mammalian cells. Finally, Sf9 cells could produce 10- to 100-fold larger amounts of E antigen than mammalian cells. These results indicate the potential of Sf9 cells for high-level production of flavivirus protein vaccines and diagnostic antigens. PMID:20668137

  19. A Japanese Encephalitis Virus Genotype 5 Molecular Clone Is Highly Neuropathogenic in a Mouse Model: Impact of the Structural Protein Region on Virulence

    PubMed Central

    de Wispelaere, Mélissanne; Frenkiel, Marie-Pascale

    2015-01-01

    ABSTRACT Japanese encephalitis virus (JEV) strains can be separated into 5 genotypes (g1 to g5) based on sequence similarity. JEV g5 strains have been rarely isolated and are poorly characterized. We report here the full characterization of a g5 virus generated using a cDNA-based technology and its comparison with a widely studied g3 strain. We did not observe any major differences between those viruses when their infectious cycles were studied in various cell lines in vitro. Interestingly, the JEV g5 strain was highly pathogenic when inoculated to BALB/c mice, which are known to be largely resistant to JEV g3 infection. The study of chimeric viruses between JEV g3 and g5 showed that there was a poor viral clearance of viruses that express JEV g5 structural proteins in BALB/c mice blood, which correlated with viral invasion of the central nervous system and encephalitis. In addition, using an in vitro model of the blood-brain barrier, we were able to show that JEV g5 does not have an enhanced capacity for entering the central nervous system, compared to JEV g3. Overall, in addition to providing a first characterization of the understudied JEV g5, our work highlights the importance of sustaining an early viremia in the development of JEV encephalitis. IMPORTANCE Genotype 5 viruses are genetically and serologically distinct from other JEV genotypes and can been associated with human encephalitis, which warrants the need for their characterization. In this study, we characterized the in vitro and in vivo properties of a JEV g5 strain and showed that it was more neuropathogenic in a mouse model than a well-characterized JEV g3 strain. The enhanced virulence of JEV g5 was associated with poor viral clearance but not with enhanced crossing of the blood-brain barrier, thus providing new insights into JEV pathogenesis. PMID:25787283

  20. Operational trials of remote mosquito trap systems for Japanese encephalitis virus surveillance in the Torres Strait, Australia.

    PubMed

    Ritchie, Scott A; van den Hurk, Andrew F; Zborowski, Paul; Kerlin, Tim J; Banks, David; Walker, James A; Lee, Jonathan M; Montgomery, Brian L; Smith, Greg A; Pyke, Alyssa T; Smith, Ina L

    2007-01-01

    Japanese encephalitis virus (JEV) appears nearly annually in the Torres Strait in far northern Queensland, Australia, and is a threat to invade the Australian mainland. Surveillance has involved the use of sentinel pigs that develop detectable viremias and antibody titers to JEV. However, pigs are amplifying hosts for JEV, and thus pose a health risk to the public and to pig handlers who bleed the pigs. A remote mosquito trap system would not have these risks. We report on trials using a remote mosquito trap system for the surveillance of JEV in the Torres Strait. The Mosquito Magnet (MM) Pro, MM Liberty Plus, and a novel updraft trap, the NAQS Mozzie Trap, were run at Badu and Moa islands in the Torres Strait and at Bamaga in the northern Cape York Peninsula from 2002-2005. TaqMan real-time polymerase chain reaction (PCR) was used to detect JEV nucleic acid in weekly mosquito collections. Sentinel pigs located at Badu were also bled and the serum processed by reverse transcriptase (RT)-PCR for JEV antigen and enzyme-linked immunosorbent assay (ELISA) for anti-JEV antibodies. JEV was detected in mosquito collections each year but not in each trap. No JEV was detected in trapped mosquitoes before detection in sentinel pigs. The mosquito trap system cost ca. AU$10,000 per site, about AU$5,000 less than a pig-based system. However, trap failures caused by mosquito-clogged motors, electrical faults, and blocked gas lines reduced the efficacy of some mosquito traps. Nonetheless, a remote mosquito trap system, employing stand alone traps and PCR for viral antigen detection, can be a safe, economical way to detect arbovirus activity in remote areas. PMID:18021024

  1. N-methylisatin-beta-thiosemicarbazone derivative (SCH 16) is an inhibitor of Japanese encephalitis virus infection in vitro and in vivo

    PubMed Central

    Sebastian, Liba; Desai, Anita; Shampur, Madhusudana N; Perumal, Yogeeswari; Sriram, D; Vasanthapuram, Ravi

    2008-01-01

    Background During the early and mid part of 20th century, several reports described the therapeutic effects of N-methylisatin-β-Thiosemicarbazone (MIBT) against pox viruses, Maloney leukemia viruses and recently against HIV. However, their ability to inhibit flavivirus replication has not been investigated. Hence the present study was designed to evaluate the antiviral activity of 14 MIBT derivatives against Flaviviruses that are prevalent in India such as Japanese Encephalitis Virus (JEV), Dengue-2 (Den-2) and West Nile viruses (WNV). Results Amongst the fourteen Mannich bases of MIBT derivatives tested one compound – SCH 16 was able to completely inhibit in vitro Japanese encephalitis virus (JEV) and West Nile virus (WNV) replication. However no antiviral activity of SCH 16 was noted against Den-2 virus replication. This compound was able to inhibit 50% of the plaques (IC50) produced by JEV and WNV at a concentration of 16 μgm/ml (0.000025 μM) and 4 μgm/ml (0.000006 μM) respectively. Furthermore, SCH 16 at a concentration of 500 mg/kg body weight administered by oral route twice daily was able to completely (100%) prevent mortality in mice challenged with 50LD50 JEV by the peripheral route. Our experiments to understand the mechanism of action suggest that SCH 16 inhibited JEV replication at the level of early protein translation. Conclusion Only one of the 14 isatin derivatives -SCH 16 exhibited antiviral action on JEV and WNV virus infection in vitro. SCH 16 was also found to completely inhibit JEV replication in vivo in a mouse model challenged peripherally with 50LD50 of the virus. These results warrant further research and development on SCH 16 as a possible therapeutic agent. PMID:18498627

  2. Development and application of an indirect enzyme-linked immunosorbent assay for serological survey of Japanese encephalitis virus infection in dogs.

    PubMed

    Shimoda, Hiroshi; Inthong, Natnaree; Noguchi, Keita; Terada, Yutaka; Nagao, Yumiko; Shimojima, Masayuki; Takasaki, Tomohiko; Rerkamnuaychoke, Worawut; Maeda, Ken

    2013-01-01

    Japanese encephalitis virus (JEV) causes serious acute encephalitis in humans and horses. Although dogs are good sentinels for assessing the risk of JEV infection to humans, a virus neutralization test has been the only method available for measuring the levels of JEV antibody in dogs. In this study, an indirect enzyme-linked immunosorbent assay (ELISA) using purified viral particles as an antigen, was developed for serological survey of JEV infection in dogs. In dogs inoculated experimentally with JEV, the ELISA detected anti-JEV IgM 3 days after infection, with IgM levels peaking 7 days after infection. Anti-JEV IgG was detected 14 days after infection and peaked on 21-28 days after infection. Virus neutralization titers correlated with anti-JEV immunoglobulins measured by the ELISA. To test the utility of the new assay, the seroprevalence of JEV infection among 102 dogs in Kyushu, Japan, was examined by IgG ELISA and by virus neutralization. The correlation coefficient between the IgG ELISA and virus neutralization was 0.813 (p<0.001); comparison of the IgG ELISA and virus neutralization showed a sensitivity and specificity of 82% and 98%, respectively. The IgG ELISA was used to survey dogs in Bangkok, Thailand and 51% of these dogs were found seropositive for JEV. These data suggest that in the capital city of Thailand, the risk of infection with JEV remains high. PMID:23046992

  3. N-glycosylation of the premembrane protein of Japanese encephalitis virus is critical for folding of the envelope protein and assembly of virus-like particles.

    PubMed

    Zai, J; Mei, L; Wang, C; Cao, S; Fu, Z F; Chen, H; Song, Y

    2013-01-01

    Premembrane (prM) and envelope (E) proteins, the major structural proteins of Japanese encephalitis virus (JEV) each contain single potential N-glycosylation site. In this study, the role of N-glycosylation of these proteins on their folding and activity were investigated. Three mutant prM and/or E (prM-E) genes lacking N-glycosylation sites were generated by site-directed mutagenesis. The effects of the N-glycan on folding, secretion and cytotoxicity of mutant proteins were determined by comparison with their wild type (wt) counterparts. Removal of N-glycan from the prM protein resulted in a complete misfolding of the E protein and failure to form virus-like particles (VLPs). A similar removal of N-glycan from the E protein led to a low efficiency of its folding and VLPs formation. The secretion and cytotoxicity of the E protein was also markedly impaired in case the glycosylation sites in the prM or E or both proteins were removed. These results suggest that the N-glycosylation of the prM protein is critical to the folding of the E protein, which makes it pivotal in the cytotoxicity of JEV particles and their production. PMID:23530821

  4. Pre-cut Filter Paper for Detecting Anti-Japanese Encephalitis Virus IgM from Dried Cerebrospinal Fluid Spots

    PubMed Central

    Bharucha, Tehmina; Chanthongthip, Anisone; Phuangpanom, Soumphou; Phonemixay, Ooyanong; Sengvilaipaseuth, Onanong; Vongsouvath, Manivanh; Lee, Sue; Newton, Paul N.; Dubot-Pérès, Audrey

    2016-01-01

    Background The use of filter paper as a simple, inexpensive tool for storage and transportation of blood, ‘Dried Blood Spots’ or Guthrie cards, for diagnostic assays is well-established. In contrast, there are a paucity of diagnostic evaluations of dried cerebrospinal fluid (CSF) spots. These have potential applications in low-resource settings, such as Laos, where laboratory facilities for central nervous system (CNS) diagnostics are only available in Vientiane. In Laos, a major cause of CNS infection is Japanese encephalitis virus (JEV). We aimed to develop a dried CSF spot protocol and to evaluate its diagnostic performance using the World Health Organisation recommended anti-JEV IgM antibody capture enzyme-linked immunosorbent assay (JEV MAC-ELISA). Methodology and Principal Findings Sample volumes, spotting techniques and filter paper type were evaluated using a CSF-substitute of anti-JEV IgM positive serum diluted in Phosphate Buffer Solution (PBS) to end-limits of detection by JEV MAC-ELISA. A conventional protocol, involving eluting one paper punch in 200μl PBS, did not detect the end-dilution, nor did multiple punches utilising diverse spotting techniques. However, pre-cut filter paper enabled saturation with five times the volume of CSF-substitute, sufficiently improving sensitivity to detect the end-dilution. The diagnostic accuracy of this optimised protocol was compared with routine, neat CSF in a pilot, retrospective study of JEV MAC-ELISA on consecutive CSF samples, collected 2009–15, from three Lao hospitals. In comparison to neat CSF, 132 CSF samples stored as dried CSF spots for one month at 25–30°C showed 81.6% (65.7–92.3 95%CI) positive agreement, 96.8% (91.0–99.3 95%CI) negative agreement, with a kappa coefficient of 0.81 (0.70–0.92 95%CI). Conclusions/Significance The novel design of pre-cut filter paper saturated with CSF could provide a useful tool for JEV diagnostics in settings with limited laboratory access. It has the

  5. Epidemiology of Japanese encephalitis: past, present, and future prospects

    PubMed Central

    Wang, Huanyu; Liang, Guodong

    2015-01-01

    Japanese encephalitis (JE) is one of severe viral encephalitis that affects individuals in Asia, western Pacific countries, and northern Australia. Although 67,900 JE cases have been estimated among 24 JE epidemic countries annually, only 10,426 have been reported in 2011. With the establishment of JE surveillance and vaccine use in some countries, the JE incidence rate has decreased; however, serious outbreaks still occur. Understanding JE epidemics and identifying the circulating JE virus genotypes will improve JE prevention and control. This review summarizes the current epidemiology data in these countries. PMID:25848290

  6. Japanese encephalitis and vaccines: past and future prospects.

    PubMed

    Paulke-Korinek, Maria; Kollaritsch, Herwig

    2008-01-01

    The Japanese encephalitis virus is the main cause of encephalitis in Asia. The vectors are mosquitoes. Every year 30,000 to 50,000 cases and 10,000 deaths from Japanese encephalitis are reported, and estimates go up to 100,000 cases. No effective antiviral therapy exists to treat this flavivirus infection. For prophylaxis vaccines are available. In Asia numerous vaccines are used regionally. The production of the only vaccine that was internationally licensed, JE-VAX, was ceased in 2005. Therefore a shortage of Japanese encephalitis vaccines might occur before new generation vaccines based on cell cultures will be available. An inactivated Vero cell-derived vaccine based on the Beijing-1 strain is developed in Japan by Biken and Kaketsuken. Another promising vaccine candidate is the inactivated whole-virus vaccine IC-51 (Strain SA14-14-2) by the Austrian company Intercell. The third interesting vaccine candidate being in the late stages of clinical trials is the genetically engineered, chimeric and live-attenuated vaccine ChimeriVaxtrade mark-JE by the UK/USA-based company Acambis. The new vaccines in the pipeline show promising results and market licensures are expected in the near future. Showing excellent tolerability, these vaccines will not only be used in the population living in endemic areas where the risk of infection is extremely high, but also for travellers and military personnel. PMID:19066766

  7. Japanese encephalitis virus NS2B-NS3 protease induces caspase 3 activation and mitochondria-mediated apoptosis in human medulloblastoma cells.

    PubMed

    Yang, Tsuey-Ching; Shiu, Su-Lian; Chuang, Pei-Hsin; Lin, Ying-Ju; Wan, Lei; Lan, Yu-Ching; Lin, Cheng-Wen

    2009-07-01

    Japanese encephalitis virus (JEV) causes severe neurological diseases with a high fatality rate. Clinical, neurophysiological and radiological features of Japanese encephalitis JE patients showed that JEV infection resulted in widespread involvement of the nervous system, including thalamus, basal ganglia, brainstem, cerebellum, cerebral cortex and spinal cord. In this study, we characterized the apoptotic effect of JEV infection and its viral proteins on the TE671 human medulloblastoma cells. JEV replicated in TE671 cells, inducing caspase 3-mediated apoptosis in MOI- and time-dependent manners. Of viral proteins, co-expression of JEV NS3 protease with NS2B cofactor significantly induced higher degrees of apoptosis and triggered higher caspase 3 activities than single expression of E, NS1, NS2B or NS3 protease in human medulloblastoma cells. Moreover, JEV NS2B-NS3 protease induced reduction of mitochondrial membrane potential and release of mitochondrial cytochrome C, which were responsible for the mitochondria-mediated apoptosis. In addition, the production of reactive oxygen species production and activation of ASK1-p38 MAPK signaling pathway might be associated with JEV NS2B-NS3 protease-induced mitochondria-mediated apoptosis. The results demonstrated that the JEV infection and the co-expression of JEV NS3 protease with NS2B cofactor induced caspase 3 activation and mitochondria-mediated apoptosis in human medulloblastoma cells, being valuable insight for cellular and molecular levels of JEV pathogenesis. PMID:19463724

  8. Chimeric Yellow Fever Virus 17D-Japanese Encephalitis Virus Vaccine: Dose-Response Effectiveness and Extended Safety Testing in Rhesus Monkeys

    PubMed Central

    Monath, T. P.; Levenbook, I.; Soike, K.; Zhang, Z.-X.; Ratterree, M.; Draper, K.; Barrett, A. D. T.; Nichols, R.; Weltzin, R.; Arroyo, J.; Guirakhoo, F.

    2000-01-01

    ChimeriVax-JE is a live, attenuated recombinant virus prepared by replacing the genes encoding two structural proteins (prM and E) of yellow fever 17D virus with the corresponding genes of an attenuated strain of Japanese encephalitis virus (JE), SA14-14-2 (T. J. Chambers et al., J. Virol. 73:3095–3101, 1999). Since the prM and E proteins contain antigens conferring protective humoral and cellular immunity, the immune response to vaccination is directed principally at JE. The prM-E genome sequence of the ChimeriVax-JE in diploid fetal rhesus lung cells (FRhL, a substrate acceptable for human vaccines) was identical to that of JE SA14-14-2 vaccine and differed from sequences of virulent wild-type strains (SA14 and Nakayama) at six amino acid residues in the envelope gene (E107, E138, E176, E279, E315, and E439). ChimeriVax-JE was fully attenuated for weaned mice inoculated by the intracerebral (i.c.) route, whereas commercial yellow fever 17D vaccine (YF-Vax) caused lethal encephalitis with a 50% lethal dose of 1.67 log10 PFU. Groups of four rhesus monkeys were inoculated by the subcutaneous route with 2.0, 3.0, 4.0, and 5.0 log10 PFU of ChimeriVax-JE. All 16 monkeys developed low viremias (mean peak viremia, 1.7 to 2.1 log10 PFU/ml; mean duration, 1.8 to 2.3 days). Neutralizing antibodies appeared between days 6 and 10; by day 30, neutralizing antibody responses were similar across dose groups. Neutralizing antibody titers to the homologous (vaccine) strain were higher than to the heterologous wild-type JE strains. All immunized monkeys and sham-immunized controls were challenged i.c. on day 54 with 5.2 log10 PFU of wild-type JE. None of the immunized monkeys developed viremia or illness and had mild residual brain lesions, whereas controls developed viremia, clinical encephalitis, and severe histopathologic lesions. Immunized monkeys developed significant (≥4-fold) increases in serum and cerebrospinal fluid neutralizing antibodies after i.c. challenge. In a

  9. Natural survivorship of immature stages of Culex vishnui (Diptera: Culicidae) complex, vectors of Japanese encephalitis virus, in rice fields in southern India.

    PubMed

    Sunish, I P; Reuben, R; Rajendran, R

    2006-03-01

    The development and survival of immatures of Culex vishnui (Diptera: Culicidae) complex, vectors of Japanese encephalitis virus, were studied in transplanted rice, Oryza savita L., fields during three crop growing seasons. The total duration of development from the first instar to adult emergence varied from 6 to 8 d. Survival rate estimates ranged from 0.003 to 0.524, but they generally were <0.1. Unusually high survival rates (0.192-0.524) were observed in summer and long-term monsoon crop seasons during 1993. A multiple regression method using backward elimination was used to analyze the factors responsible for these variations. The model identified nine parameters related with survival rates that explained 99% of the variance. Area of water surface and hardness were negatively related, whereas green algae, notonectid adults, anisopterans, dytiscids, salinity, water depth, and dissolved oxygen were positively associated with immature survival. PMID:16619597

  10. Effect of fatty acids on growth of Japanese encephalitis virus cultivated in BHK-21 cells and phospholipid metabolism of the infected cells.

    PubMed Central

    Makino, S; Jenkin, H M

    1975-01-01

    Growth of Japanese encephalitis virus (JEV) in BHK-21 cells was stimulated in the presence of 20 to 40 mug of the sodium salt of oleic acid (cis-9-octadecenoic acid, 9-18:1) per ml supplemented in Waymouth medium. The stimulatory effect of the salt was highest when 9-18:1 was added after adsorption of the virus. Study of the effect of other fatty acids on growth of JEV showed the following results: the longer the chain length of the saturated fatty acid salt, the higher the stimulatory effect on viral growth. In contrast, polyunsaturated fatty acids had an inhibitory effect on viral growth. The effect of isomeric cis-octadecenoic acids on viral growth was variable, depending upon the position of the double bond. The cis-6-octadecenoic acid had the highest inhibitory effect on growth of JEV compared to other isomeric octadecenoic acids. The sodium salt of (1-14C) cis-9-octadecenoic acid (9-18:1, 20 mug/ml) was rapidly incorporated into control and JEV-infected cells. Specific radioactivity in phosphatidylcholine dropped 12 to 24 h after virus inoculation, whereas synthesis of phosphatidylethanolamine increased 12 to 24 h after virus inoculation in infected cells compared to uninfected cells. Results from these studies suggest that phospholipid metabolism of infected cells is markedly changed, which can be associated with altered fatty acid metabolism when using labeled 9-18:1 fatty acid as a marker. PMID:1167607

  11. Sensitive and specific detection of strains of Japanese encephalitis virus using a one-step TaqMan RT-PCR technique.

    PubMed

    Huang, Jau-Ling; Lin, Hui-Tsu; Wang, Yu-Ming; Weng, Ming-Hui; Ji, Da-Der; Kuo, Ming-Der; Liu, Huan-Wun; Lin, Chang-Shen

    2004-12-01

    A rapid, sensitive, and accurate laboratory diagnostic test is needed for distinguishing Japanese encephalitis virus (JEV) from other diseases featuring similar clinical symptoms and also for preventing potential outbreaks. In this study, a TaqMan reverse transcription (RT)-polymerase chain reaction (PCR) assay was developed for rapid detection and quantification of the viral RNA of various JEV strains. A consensus JEV NS3 region was chosen to design the primers and the TaqMan probe. The JEV TaqMan assay used the EZ-rTtH RT-PCR system featuring advantages such as a one-step, high-temperature RT reaction modality and preventing carry-over contamination. The sensitivity of the JEV TaqMan assay for detecting in vitro-transcribed JEV NS3 RNA was estimated to be one to five copies of RNA per reaction. For cultured JE virions, less than 40 plaque forming unit (PFU)/ml of virus load (corresponding to 0.07 PFU/test) could be detected. In addition, the JEV TaqMan assay could detect all seven strains of JEV tested, but provided negative results for nine other flaviviruses and encephalitis viruses tested. The JEV TaqMan assay demonstrated greater sensitivity and specificity than traditional RT-PCR methods as has been previously reported. The application of the JEV TaqMan assay herein has been shown to the sensitive detection of the JEV from both mosquito pools and also JEV-spiking human blood. The assay should be of use in diagnostic laboratory conduct and could be used to replace or complement time-consuming viral-culture methods, thus achieving more rapid, sensitive, and highly specific identification of JEV infection. PMID:15484282

  12. Standardization of serum neutralization assay of Japanese encephalitis virus (Nakayama NIH strain) on BHK-21 (Cl-13) cell line.

    PubMed

    Singh, S; Sharma, M; Kumar, S; Gowal, D

    2015-09-01

    Potency testing of Japanese encephalitis (JE) vaccine has been a complex process since its inception. To overcome difficulties encountered therein, an alternative assay, serum neutralization test (SNT), using Baby Hamster Kidney 21 cell line, has been standardized. The antibody response generated against JE vaccine was quantified and the assay was found to be sensitive and specific enough with significant accuracy and precision. On analysis of cell count, a cell concentration of 1.5 x 104 was selected as the optimum, since concentrations above and below this resulted in problems of confluent monolayer formation and incomplete monolayer formation. Incubation time has also been standardized for measuring cytopathic effect (CPE). Out of the four different time points selected, 90 min was found to be adequate for 50% reduction in the amount of CPE. The accuracy of SNT assay is explained in terms of fiducial limits at 95% level. Inter- and intra-assay reproducibility testing was also performed. A comparison of potency of JE vaccine by plaque reduction neutralization test (PRNT) and SNT method was conducted and it was found that SNT can be a reliable approach for estimating the potency of JE vaccine. The results of this study throw a light on the utility of SNT assay for the potency estimation of JE vaccine in routine practice. PMID:26435146

  13. In vitro and in vivo characterization of chimeric duck Tembusu virus based on Japanese encephalitis live vaccine strain SA14-14-2.

    PubMed

    Wang, Hong-Jiang; Liu, Long; Li, Xiao-Feng; Ye, Qing; Deng, Yong-Qiang; Qin, E-De; Qin, Cheng-Feng

    2016-07-01

    Duck Tembusu virus (DTMUV), a newly identified flavivirus, has rapidly spread to China, Malaysia and Thailand. The potential threats to public health have been well-highlighted; however its virulence and pathogenesis remain largely unknown. Here, by using reverse genetics, a recombinant chimeric DTMUV based on Japanese encephalitis live vaccine strain SA14-14-2 was obtained by substituting the corresponding prM and E genes (named ChinDTMUV). In vitro characterization demonstrated that ChinDTMUV replicated efficiently in mammalian cells with small-plaque phenotype in comparison with its parental viruses. Mouse tests showed ChinDTMUV exhibited avirulent phenotype in terms of neuroinvasiveness, while it retained neurovirulence from its parental virus DTMUV. Furthermore, immunization with ChinDTMUV was evidenced to elicit robust IgG and neutralizing antibody responses in mice. Overall, we successfully developed a viable chimeric DTMUV, and these results provide a useful platform for further investigation of the pathogenesis of DTMUV and development of a live attenuated DTMUV vaccine candidate. PMID:27100268

  14. Antibody to the nonstructural protein NS1 of Japanese encephalitis virus: potential application of mAb-based indirect ELISA to differentiate infection from vaccination.

    PubMed

    Shu, P Y; Chen, L K; Chang, S F; Yueh, Y Y; Chow, L; Chien, L J; Chin, C; Lin, T H; Huang, J H

    2001-02-01

    An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect and differentiate the antibody responses to Japanese encephalitis (JE) virus nonstructural protein NS1 between infected and vaccinated individuals. The results showed that all convalescent sera from JE patients contained NS1-specific IgG antibodies, while 65 and 40% of these sera showed detectable NS1-specific IgM and IgA antibodies, respectively. Specificity analysis showed that NS1-specific IgM and IgA antibodies from JE patients do not cross-react to dengue virus NS1 glycoprotein, while IgG antibodies from 10% of JE patients showed significant cross-reaction to dengue virus NS1 glycoprotein. To differentiate infection from vaccination, the immune sera from 24 children vaccinated with inactivated JE vaccine were analyzed. The data showed that none of these immune sera had detectable NS1-specific IgG antibodies. The results demonstrated the potential application of JE NS1-specific indirect ELISA to differentiate infection from vaccination. PMID:11166901

  15. Epidemiological situation of Japanese encephalitis in Nepal.

    PubMed

    Bista, M B; Shrestha, J M

    2005-01-01

    A human Japanese encephalitis (JE) case is considered to have elevated temperature (over 380 C) along with altered consciousness or unconsciousness and is generally confirmed serologically by finding of specific anti-JE IgM in the cerebro spinal fluid. No specific treatment for JE is available. Only supportive treatment like meticulous nursing care, introduction of Ryle's tube if the patient is unconscious, dextrose solution if dehydration is present, manitol injection in case of raised cranial temperature and diazepam in case of convulsion. Intra venous fluids, indwelling catheter in conscious patient and corticosteroids unless indicated should be avoided. Pigs, wading birds and ducks have been incriminated as important vertebrate amplifying hosts for JE virus due to viremia in them. Man along with bovines, ovines and caprines is involved in transmission cycle as accidental hosts and plays no role in perpetuating the virus due to the lack of viremia in them. The species Cx tritaeniorhyncus is suspected to be the principal vector of JE in Nepal as the species is abundantly found in the rice-field ecosystem of the endemic areas during the transmission season and JE virus isolates have been obtained from a pool of Cx tritaeniorhyncus females. Mosquito vector become infective 14 days after acquiring the JR virus from the viremic host. The disease was first recorded in Nepal in 1978 as an epidemic in Rupandehi district of the Western Development Region (WDR) and Morang of the Eastern Region (EDR). At present the disease is endemic in 24 districts. Although JE as found endemic mainly in tropical climate areas, existence and proliferation of encephalitis causing viruses in temperate and cold climates of hills and valleys are possible. Total of 26,667 cases and 5,381 deaths have been reported with average case fatality rate of 20.2% in an aggregate since 1978. More than 50% of morbidity and 60% mortality occur in the age group below 15 years. Upsurge of cases take place

  16. Formalin Inactivation of Japanese Encephalitis Virus Vaccine Alters the Antigenicity and Immunogenicity of a Neutralization Epitope in Envelope Protein Domain III

    PubMed Central

    Fan, Yi-Chin; Chiu, Hsien-Chung; Chen, Li-Kuang; Chang, Gwong-Jen J.; Chiou, Shyan-Song

    2015-01-01

    Formalin-inactivated Japanese encephalitis virus (JEV) vaccines are widely available, but the effects of formalin inactivation on the antigenic structure of JEV and the profile of antibodies elicited after vaccination are not well understood. We used a panel of monoclonal antibodies (MAbs) to map the antigenic structure of live JEV virus, untreated control virus (UCV), formalin-inactivated commercial vaccine (FICV), and formalin-inactivated virus (FIV). The binding activity of T16 MAb against Nakayama-derived FICV and several strains of FIV was significantly lower compared to live virus and UCV. T16 MAb, a weakly neutralizing JEV serocomplex antibody, was found to inhibit JEV infection at the post-attachment step. The T16 epitope was mapped to amino acids 329, 331, and 389 within domain III (EDIII) of the envelope (E) glycoprotein. When we explored the effect of formalin inactivation on the immunogenicity of JEV, we found that Nakayama-derived FICV, FIV, and UCV all exhibited similar immunogenicity in a mouse model, inducing anti-JEV and anti-EDII 101/106/107 epitope-specific antibodies. However, the EDIII 329/331/389 epitope-specific IgG antibody and neutralizing antibody titers were significantly lower for FICV-immunized and FIV-immunized mouse serum than for UCV-immunized. Formalin inactivation seems to alter the antigenic structure of the E protein, which may reduce the potency of commercially available JEV vaccines. Virus inactivation by H2O2, but not by UV or by short-duration and higher temperature formalin treatment, is able to maintain the antigenic structure of the JEV E protein. Thus, an alternative inactivation method, such as H2O2, which is able to maintain the integrity of the E protein may be essential to improving the potency of inactivated JEV vaccines. PMID:26495991

  17. MicroRNA-33a-5p Modulates Japanese Encephalitis Virus Replication by Targeting Eukaryotic Translation Elongation Factor 1A1

    PubMed Central

    Chen, Zheng; Ye, Jing; Ashraf, Usama; Li, Yunchuan; Wei, Siqi; Wan, Shengfeng; Zohaib, Ali; Song, Yunfeng; Chen, Huanchun

    2016-01-01

    ABSTRACT Japanese encephalitis virus (JEV) is a typical mosquito-borne flavivirus responsible for acute encephalitis and meningitis in humans. However, the molecular mechanism for JEV pathogenesis is still unclear. MicroRNAs (miRNAs) are small noncoding RNAs that act as gene regulators. They are directly or indirectly involved in many cellular functions owing to their ability to target mRNAs for degradation or translational repression. However, how cellular miRNAs are regulated and their functions during JEV infection are largely unknown. In the present study, we found that JEV infection downregulated the expression of endogenous cellular miR-33a-5p. Notably, artificially transfecting with miR-33a-5p mimics led to a significant decrease in viral replication, suggesting that miR-33a-5p acts as a negative regulator of JEV replication. A dual-luciferase reporter assay identified eukaryotic translation elongation factor 1A1 (EEF1A1) as one of the miR-33a-5p target genes. Our study further demonstrated that EEF1A1 can interact with the JEV proteins NS3 and NS5 in replicase complex. Through this interaction, EEF1A1 can stabilize the components of viral replicase complex and thus facilitates viral replication during JEV infection. Taken together, these results suggest that miR-33a-5p is downregulated during JEV infection, which contributes to viral replication by increasing the intracellular level of EEF1A1, an interaction partner of JEV NS3 and NS5. This study provides a better understanding of the molecular mechanisms of JEV pathogenesis. IMPORTANCE MiRNAs are critical regulators of gene expression that utilize sequence complementarity to bind to and modulate the stability or translation efficiency of target mRNAs. Accumulating data suggest that miRNAs regulate a wide variety of molecular mechanisms in the host cells during viral infections. JEV, a neurotropic flavivirus, is one of the major causes of acute encephalitis in humans worldwide. The roles of cellular mi

  18. Gold nanoparticle-based RT-PCR and real-time quantitative RT-PCR assays for detection of Japanese encephalitis virus

    NASA Astrophysics Data System (ADS)

    Huang, Su-Hua; Yang, Tsuey-Ching; Tsai, Ming-Hong; Tsai, I.-Shou; Lu, Huang-Chih; Chuang, Pei-Hsin; Wan, Lei; Lin, Ying-Ju; Lai, Chih-Ho; Lin, Cheng-Wen

    2008-10-01

    Virus isolation and antibody detection are routinely used for diagnosis of Japanese encephalitis virus (JEV) infection, but the low level of transient viremia in some JE patients makes JEV isolation from clinical and surveillance samples very difficult. We describe the use of gold nanoparticle-based RT-PCR and real-time quantitative RT-PCR assays for detection of JEV from its RNA genome. We tested the effect of gold nanoparticles on four different PCR systems, including conventional PCR, reverse-transcription PCR (RT-PCR), and SYBR green real-time PCR and RT-PCR assays for diagnosis in the acute phase of JEV infection. Gold nanoparticles increased the amplification yield of the PCR product and shortened the PCR time compared to the conventional reaction. In addition, nanogold-based real-time RT-PCR showed a linear relationship between Ct and template amount using ten-fold dilutions of JEV. The nanogold-based RT-PCR and real-time quantitative RT-PCR assays were able to detect low levels (1-10 000 copies) of the JEV RNA genomes extracted from culture medium or whole blood, providing early diagnostic tools for the detection of low-level viremia in the acute-phase infection. The assays described here were simple, sensitive, and rapid approaches for detection and quantitation of JEV in tissue cultured samples as well as clinical samples.

  19. Knowledge Obtained from an Elderly Case of Japanese Encephalitis.

    PubMed

    Itoh, Kyoko; Iwamoto, Kazuhide; Satoh, Yu; Fujita, Tomoaki; Takahashi, Kenta; Katano, Harutaka; Hasegawa, Hideki; Takasaki, Tomohiko; Tando, So; Fushiki, Shinji

    2016-01-01

    The nationwide introduction of a Japanese encephalitis (JE) vaccine has contributed to a reduction in the annual infection rate of JE in Japan. However, the current neutralizing antibody prevalence ratio in Japan is approximately 20% in children 3-4 years of age and in people in their forties and fifties. We herein report a man with JE who was definitively diagnosed by multi-virus real-time polymerase chain reaction employing biopsied brain tissue and serological examinations. JE should be kept in mind when a patient has severe encephalitis of unknown etiology. In order to protect the susceptible population from JE, vaccination is recommended, especially for children and middle-aged people. PMID:27580555

  20. Dynamic changes in global microRNAome and transcriptome reveal complex miRNA-mRNA regulated host response to Japanese Encephalitis Virus in microglial cells

    PubMed Central

    Kumari, Bharti; Jain, Pratistha; Das, Shaoli; Ghosal, Suman; Hazra, Bibhabasu; Trivedi, Ashish Chandra; Basu, Anirban; Chakrabarti, Jayprokas; Vrati, Sudhanshu; Banerjee, Arup

    2016-01-01

    Microglia cells in the brain play essential role during Japanese Encephalitis Virus (JEV) infection and may lead to change in microRNA (miRNA) and mRNA profile. These changes may together control disease outcome. Using Affymetrix microarray platform, we profiled cellular miRNA and mRNA expression at multiple time points during viral infection in human microglial (CHME3) cells. In silico analysis of microarray data revealed a phased pattern of miRNAs expression, associated with JEV replication and provided unique signatures of infection. Target prediction and pathway enrichment analysis identified anti correlation between differentially expressed miRNA and the gene expression at multiple time point which ultimately affected diverse signaling pathways including Notch signaling pathways in microglia. Activation of Notch pathway during JEV infection was demonstrated in vitro and in vivo. The expression of a subset of miRNAs that target multiple genes in Notch signaling pathways were suppressed and their overexpression could affect JEV induced immune response. Further analysis provided evidence for the possible presence of cellular competing endogenous RNA (ceRNA) associated with innate immune response. Collectively, our data provide a uniquely comprehensive view of the changes in the host miRNAs induced by JEV during cellular infection and identify Notch pathway in modulating microglia mediated inflammation. PMID:26838068

  1. A Chimeric Dengue Virus Vaccine using Japanese Encephalitis Virus Vaccine Strain SA14-14-2 as Backbone Is Immunogenic and Protective against Either Parental Virus in Mice and Nonhuman Primates

    PubMed Central

    Li, Xiao-Feng; Deng, Yong-Qiang; Yang, Hui-Qiang; Zhao, Hui; Jiang, Tao; Yu, Xue-Dong; Li, Shi-Hua; Ye, Qing; Zhu, Shun-Ya; Wang, Hong-Jiang; Zhang, Yu; Ma, Jie; Yu, Yong-Xin; Liu, Zhong-Yu; Qin, E-De; Shi, Pei-Yong

    2013-01-01

    The development of a safe and efficient dengue vaccine represents a global challenge in public health. Chimeric dengue viruses (DENV) based on an attenuated flavivirus have been well developed as vaccine candidates by using reverse genetics. In this study, based on the full-length infectious cDNA clone of the well-known Japanese encephalitis virus live vaccine strain SA14-14-2 as a backbone, a novel chimeric dengue virus (named ChinDENV) was rationally designed and constructed by replacement with the premembrane and envelope genes of dengue 2 virus. The recovered chimeric virus showed growth and plaque properties similar to those of the parental DENV in mammalian and mosquito cells. ChinDENV was highly attenuated in mice, and no viremia was induced in rhesus monkeys upon subcutaneous inoculation. ChinDENV retained its genetic stability and attenuation phenotype after serial 15 passages in cultured cells. A single immunization with various doses of ChinDENV elicited strong neutralizing antibodies in a dose-dependent manner. When vaccinated monkeys were challenged with wild-type DENV, all animals except one that received the lower dose were protected against the development of viremia. Furthermore, immunization with ChinDENV conferred efficient cross protection against lethal JEV challenge in mice in association with robust cellular immunity induced by the replicating nonstructural proteins. Taken together, the results of this preclinical study well demonstrate the great potential of ChinDENV for further development as a dengue vaccine candidate, and this kind of chimeric flavivirus based on JE vaccine virus represents a powerful tool to deliver foreign antigens. PMID:24109223

  2. Construction of an infectious molecular clone of Japanese encephalitis virus genotype V and its derivative subgenomic replicon capable of expressing a foreign gene.

    PubMed

    Ishikawa, Tomohiro; Abe, Makoto; Masuda, Michiaki

    2015-01-01

    Japanese encephalitis virus (JEV) genotype V was originally isolated in Malaysia in 1952 and has long been restricted to the area. In 2009, sudden emergence of the genotype V in China and Korea was reported, suggesting expansion of its geographical distribution. Although studies on the genotype V are becoming more important, they have been limited partly due to lack of its infectious molecular clone. In this study, a plasmid carrying cDNA corresponding to the entire genome of JEV Muar strain, which belongs to genotype V, in the downstream of T7 promoter was constructed. Electroporation of viral RNA transcribed by T7 RNA polymerase (T7RNAP) in vitro from the plasmid led to production of progeny viruses both in mammalian and mosquito cells. Also, transfection of the infectious clone plasmid into mammalian cells expressing T7RNAP transiently or stably was demonstrated to generate infectious progenies. When the viral structural protein genes were partially deleted from the full-length cDNA, the subgenomic RNA transcribed in vitro from the modified plasmid was shown to replicate itself in mammalian cells as a replicon. The replicon carrying the firefly luciferase gene in place of the deleted structural protein genes was also shown to efficiently replicate itself and express luciferase in mammalian cells. Compared with the replicon derived from JEV genotype III (Nakayama strain), the genotype V-derived replicon appeared to be more tolerant to introduction of a foreign gene. The infectious clone and the replicons constructed in this study may serve as useful tools for characterizing JEV genotype V. PMID:25451067

  3. Endothelial Japanese encephalitis virus infection enhances migration and adhesion of leukocytes to brain microvascular endothelia via MEK-dependent expression of ICAM1 and the CINC and RANTES chemokines.

    PubMed

    Lai, Ching-Yi; Ou, Yen-Chuan; Chang, Cheng-Yi; Pan, Hung-Chuan; Chang, Chen-Jung; Liao, Su-Lan; Su, Hong-Lin; Chen, Chun-Jung

    2012-10-01

    Currently, the underlying mechanisms and the specific cell types associated with Japanese encephalitis-associated leukocyte trafficking are not understood. Brain microvascular endothelial cells represent a functional barrier and could play key roles in leukocyte central nervous system trafficking. We found that cultured brain microvascular endothelial cells were susceptible to Japanese encephalitis virus (JEV) infection with limited amplification. This type of JEV infection had negligible effects on cell viability and barrier integrity. Instead, JEV-infected endothelial cells attracted more leukocytes adhesion onto surfaces and the supernatants promoted chemotaxis of leukocytes. Infection with JEV was found to elicit the elevated production of intercellular adhesion molecule-1, cytokine-induced neutrophil chemoattractant-1, and regulated-upon-activation normal T-cell expressed and secreted, contributing to the aforementioned leukocyte adhesion and chemotaxis. We further demonstrated that extracellular signal-regulated kinase was a key upstream regulator which stimulated extensive endothelial gene induction by up-regulating cytosolic phospholipase A₂, NF-κB, and cAMP response element-binding protein via signals involving phosphorylation. These data suggest that JEV infection could activate brain microvascular endothelial cells and modify their characteristics without compromising the barrier integrity, making them favorable for the recruitment and adhesion of circulating leukocytes, thereby together with other unidentified barrier-disrupting mechanisms contributing to Japanese encephalitis and associated neuroinflammation. PMID:22845610

  4. Japanese encephalitis in two children--United States, 2010.

    PubMed

    2011-03-11

    Japanese encephalitis virus (JEV) is the leading cause of vaccine-preventable encephalitis in Asia and the western Pacific. JEV is maintained in an enzootic cycle involving mosquitoes and amplifying vertebrate hosts, mainly pigs and wading birds. The virus is transmitted to humans primarily by Culex mosquitoes, which breed in flooded rice fields and pools of stagnant water and most often feed outdoors during the evening and night. JEV transmission occurs mainly in rural agricultural areas, but occasional human cases occur in urban areas. Japanese encephalitis (JE) in persons who have traveled or lived overseas is diagnosed infrequently in the United States, with only four cases identified from 1992 (when a JE vaccine was first licensed in the United States) to 2008. This report describes the only cases diagnosed in the United States and reported to CDC since then. The first was a fatal case in a U.S. child who had visited relatives in the Philippines. The other occurred in a refugee who became ill while traveling from Thailand to the United States and whose diagnosis was complicated by concurrent neurocysticercosis. JE should be considered in the differential diagnosis for any patient with an acute neurologic infection who recently has been in a JE-endemic country. Travelers to JE-endemic countries should be advised of the risk for JE and the importance of personal protective measures to prevent mosquito bites. JE vaccine should be considered for travelers who might be at greater risk based on the season, location, and duration of their visit and their planned activities. PMID:21389931

  5. Past, Present, and Future of Japanese Encephalitis

    PubMed Central

    Weiss, Svenja; Keiser, Jennifer; Utzinger, Jürg; Wiedenmayer, Karin

    2009-01-01

    Japanese encephalitis (JE), a vector-borne viral disease, is endemic to large parts of Asia and the Pacific. An estimated 3 billion people are at risk, and JE has recently spread to new territories. Vaccination programs, increased living standards, and mechanization of agriculture are key factors in the decline in the incidence of this disease in Japan and South Korea. However, transmission of JE is likely to increase in Bangladesh, Cambodia, Indonesia, Laos, Myanmar, North Korea, and Pakistan because of population growth, intensified rice farming, pig rearing, and the lack of vaccination programs and surveillance. On a global scale, however, the incidence of JE may decline as a result of large-scale vaccination programs implemented in China and India. PMID:19116041

  6. The C Terminus of the Core β-Ladder Domain in Japanese Encephalitis Virus Nonstructural Protein 1 Is Flexible for Accommodation of Heterologous Epitope Fusion

    PubMed Central

    Yen, Li-Chen; Liao, Jia-Teh; Lee, Hwei-Jen; Chou, Wei-Yuan; Chen, Chun-Wei; Lin, Yi-Ling

    2015-01-01

    ABSTRACT NS1 is the only nonstructural protein that enters the lumen of the endoplasmic reticulum (ER), where NS1 is glycosylated, forms a dimer, and is subsequently secreted during flavivirus replication as dimers or hexamers, which appear to be highly immunogenic to the infected host, as protective immunity can be elicited against homologous flavivirus infections. Here, by using a trans-complementation assay, we identified the C-terminal end of NS1 derived from Japanese encephalitis virus (JEV), which was more flexible than other regions in terms of housing foreign epitopes without a significant impact on virus replication. This mapped flexible region is located in the conserved tip of the core β-ladder domain of the multimeric NS1 structure and is also known to contain certain linear epitopes, readily triggering specific antibody responses from the host. Despite becoming attenuated, recombinant JEV with insertion of a neutralizing epitope derived from enterovirus 71 (EV71) into the C-terminal end of NS1 not only could be normally released from infected cells, but also induced dual protective immunity for the host to counteract lethal challenge with either JEV or EV71 in neonatal mice. These results indicated that the secreted multimeric NS1 of flaviviruses may serve as a natural protein carrier to render epitopes of interest more immunogenic in the C terminus of the core β-ladder domain. IMPORTANCE The positive-sense RNA genomes of mosquito-borne flaviviruses appear to be flexible in terms of accommodating extra insertions of short heterologous antigens into their virus genes. Here, we illustrate that the newly identified C terminus of the core β-ladder domain in NS1 could be readily inserted into entities such as EV71 epitopes, and the resulting NS1-epitope fusion proteins appeared to maintain normal virus replication, secretion ability, and multimeric formation from infected cells. Nonetheless, such an insertion attenuated the recombinant JEV in mice

  7. Japanese encephalitis: Challenges and intervention opportunities in Nepal

    PubMed Central

    Ghimire, Shristi; Dhakal, Santosh

    2015-01-01

    Japanese encephalitis (JE) is a mosquito borne zoonotic disease caused by JE virus (JEV). JE has been endemic in Terai region, the lowland plains of Nepal bordering India, since 1978. However, in recent years cases of JE has been continuously reported from high altitude zones of hills and mountains. Irrigated rice farming system, expanded pig husbandry practices, inadequate vaccine coverage, low level of public awareness and climate change favoring mosquito breeding in higher altitudes might be the probable risk factors for emergence and re-emergence of JE in Nepal. Repeated outbreak in endemic areas and geographical expansion to newer areas have created huge challenge for JE prevention and control. At present, JE is one of the major public health concern of Nepal. Expanding vaccine coverage, improving agricultural practices, generating public awareness, supporting for use of mosquito avoiding practices and regional collaboration at border against JE can be helpful in getting better control over it in future. PMID:27046998

  8. Japanese encephalitis: Challenges and intervention opportunities in Nepal.

    PubMed

    Ghimire, Shristi; Dhakal, Santosh

    2015-01-01

    Japanese encephalitis (JE) is a mosquito borne zoonotic disease caused by JE virus (JEV). JE has been endemic in Terai region, the lowland plains of Nepal bordering India, since 1978. However, in recent years cases of JE has been continuously reported from high altitude zones of hills and mountains. Irrigated rice farming system, expanded pig husbandry practices, inadequate vaccine coverage, low level of public awareness and climate change favoring mosquito breeding in higher altitudes might be the probable risk factors for emergence and re-emergence of JE in Nepal. Repeated outbreak in endemic areas and geographical expansion to newer areas have created huge challenge for JE prevention and control. At present, JE is one of the major public health concern of Nepal. Expanding vaccine coverage, improving agricultural practices, generating public awareness, supporting for use of mosquito avoiding practices and regional collaboration at border against JE can be helpful in getting better control over it in future. PMID:27046998

  9. Surveillance for Japanese encephalitis in villages near Madurai, Tamil Nadu, India.

    PubMed

    Mani, T R; Rao, C V; Rajendran, R; Devaputra, M; Prasanna, Y; Hanumaiah; Gajanana, A; Reuben, R

    1991-01-01

    A simple dusk index was developed to monitor the density of recognized vectors of Japanese encephalitis virus (JEV) based on hand catches around cattlesheds at dusk and parous rates. When used routinely in combination with sentinel animal studies for surveillance in villages with a high prevalence (46.2%) of neutralizing antibodies against JEV in children under 16 years, there was a peak in vector density and virus activity during the north-east monsoon period, October-December. The reasons for an unusual outbreak of cases of encephalitis during the summer months of 1984 are discussed. PMID:1653473

  10. St. Louis Encephalitis

    MedlinePlus

    ... Virus Transmission Epidemiology & Geographic Distribution Symptoms & Treatment Arboviral Diagnostic Testing Links & References Technical Fact Sheet Other diseases transmitted by mosquitoes Chikungunya Dengue Eastern Equine Encephalitis Japanese Encephalitis Malaria La Crosse ...

  11. Genetic variation of St. Louis encephalitis virus

    PubMed Central

    May, Fiona J.; Li, Li; Zhang, Shuliu; Guzman, Hilda; Beasley, David W. C.; Tesh, Robert B.; Higgs, Stephen; Raj, Pushker; Bueno, Rudy; Randle, Yvonne; Chandler, Laura; Barrett, Alan D. T.

    2008-01-01

    St. Louis encephalitis virus (SLEV) has been regularly isolated throughout the Americas since 1933. Previous phylogenetic studies involving 62 isolates have defined seven major lineages (I–VII), further divided into 14 clades. In this study, 28 strains isolated in Texas in 1991 and 2001–2003, and three older, previously unsequenced strains from Jamaica and California were sequenced over the envelope protein gene. The inclusion of these new sequences, and others published since 2001, has allowed better delineation of the previously published SLEV lineages, in particular the clades of lineage II. Phylogenetic analysis of 106 isolates identified 13 clades. All 1991 and 2001–2003 isolates from Nueces, Jefferson and Harris Counties (Texas Gulf Coast) group in clade IIB with other isolates from these counties isolated during the 1980s and 1990s. This lack of evidence for introduction of novel strains into the Texas Gulf Coast over a long period of time is consistent with overwintering of SLEV in this region. Two El Paso isolates, both from 2002, group in clade VA with recent Californian isolates from 1998–2001 and some South American strains with a broad temporal range. Overall, these data are consistent with multiple introductions of SLEV from South America into North America, and provide support for the hypothesis that in most situations, SLEV circulates within a locality, with occasional incursions from other areas. Finally, SLEV has much lower nucleotide (10.1 %) and amino acid variation (2.8 %) than other members of the Japanese encephalitis virus complex (maximum variation 24.6 % nucleotide and 11.8 % amino acid). PMID:18632961

  12. Isolation of Saint Louis Encephalitis Virus from a Horse with Neurological Disease in Brazil

    PubMed Central

    Rosa, Roberta; Costa, Erica Azevedo; Marques, Rafael Elias; Oliveira, Taismara Simas; Furtini, Ronaldo; Bomfim, Maria Rosa Quaresma; Teixeira, Mauro Martins; Paixão, Tatiane Alves; Santos, Renato Lima

    2013-01-01

    St. Louis encephalitis virus (SLEV) is a causative agent of encephalitis in humans in the Western hemisphere. SLEV is a positive-sense RNA virus that belongs to the Flavivirus genus, which includes West Nile encephalitis virus, Japanese encephalitis virus, Dengue virus and other medically important viruses. Recently, we isolated a SLEV strain from the brain of a horse with neurological signs in the countryside of Minas Gerais, Brazil. The SLEV isolation was confirmed by reverse-transcription RT-PCR and sequencing of the E protein gene. Virus identity was also confirmed by indirect immunofluorescence using commercial antibodies against SLEV. To characterize this newly isolated strain in vivo, serial passages in newborn mice were performed and led to hemorrhagic manifestations associated with recruitment of inflammatory cells into the central nervous system of newborns. In summary this is the first isolation of SLEV from a horse with neurological signs in Brazil. PMID:24278489

  13. Two Uncommon Causes of Guillain-Barré Syndrome: Hepatitis E and Japanese Encephalitis

    PubMed Central

    Bandyopadhyay, Dhrubajyoti; Ganesan, Vijayan; Choudhury, Cankatika; Kar, Suvrendu Sankar; Karmakar, Parthasarathi; Choudhary, Vivek; Banerjee, Prasun; Bhar, Debarati; Hajra, Adrija; Layek, Manas; Mukhopadhyay, Sabyasachi

    2015-01-01

    We are presenting two cases of Guillain-Barré syndrome where it is preceded by hepatitis E virus (HEV) and Japanese encephalitis virus (JEV) infection, respectively. Our first case is a forty-three-year-old nondiabetic, nonhypertensive female who was initially diagnosed with acute HEV induced viral hepatitis and subsequently developed acute onset ascending quadriparesis with lower motor neuron type of bilateral facial nerve palsies and respiratory failure. Second patient was a 14-year-old young male who presented with meningoencephalitis with acute onset symmetric flaccid paraparesis. After thorough investigations it was revealed as a case of Japanese encephalitis. Our idea of reporting these two cases is to make ourselves aware about this potential complication of these two common infections. PMID:26798531

  14. Neuropathogenesis of Japanese Encephalitis in a Primate Model

    PubMed Central

    Myint, Khin Saw Aye; Kipar, Anja; Jarman, Richard G.; Gibbons, Robert V.; Perng, Guey Chuen; Flanagan, Brian; Mongkolsirichaikul, Duangrat; Van Gessel, Yvonne; Solomon, Tom

    2014-01-01

    Background Japanese encephalitis (JE) is a major cause of mortality and morbidity for which there is no treatment. In addition to direct viral cytopathology, the inflammatory response is postulated to contribute to the pathogenesis. Our goal was to determine the contribution of bystander effects and inflammatory mediators to neuronal cell death. Methodology/Principal Findings Material from a macaque model was used to characterize the inflammatory response and cytopathic effects of JE virus (JEV). Intranasal JEV infection induced a non-suppurative encephalitis, dominated by perivascular, infiltrates of mostly T cells, alongside endothelial cell activation, vascular damage and blood brain barrier (BBB) leakage; in the adjacent parenchyma there was macrophage infiltration, astrocyte and microglia activation. JEV antigen was mostly in neurons, but there was no correlation between intensity of viral infection and degree of inflammatory response. Apoptotic cell death occurred in both infected and non-infected neurons. Interferon-α, which is a microglial activator, was also expressed by both. Tumour Necrosis Factor-α, inducible nitric oxide synthase and nitrotyrosine were expressed by microglial cells, astrocytes and macrophages. The same cells expressed matrix metalloproteinase (MMP)-2 whilst MMP-9 was expressed by neurons. Conclusions/Significance The results are consistent with JEV inducing neuronal apoptotic death and release of cytokines that initiate microglial activation and release of pro-inflammatory and apoptotic mediators with subsequent apoptotic death of both infected and uninfected neurons. Activation of astrocytes, microglial and endothelial cells likely contributes to inflammatory cell recruitment and BBB breakdown. It appears that neuronal apoptotic death and activation of microglial cells and astrocytes play a crucial role in the pathogenesis of JE. PMID:25102067

  15. Japanese encephalitis vaccines: moving away from the mouse brain.

    PubMed

    Zanin, Mark P; Webster, Diane E; Martin, Jenny L; Wesselingh, Steven L

    2003-06-01

    Japanese encephalitis (JE) is a severe disease that is widespread throughout Asia and is spreading beyond its traditional boundaries. Three vaccines are currently in use against JE but only one is available internationally, a mouse-brain-derived inactivated vaccine first used in the 1930s. Although this vaccine has been effective in reducing the incidence of JE, it is relatively expensive and has been linked to severe allergic and neurological reactions. Cell-culture-derived inactivated and attenuated vaccines have been developed but are only used in the People's Republic of China. Other vaccines currently in various stages of development are DNA vaccines, a chimeric yellow fever-JE viral vaccine, virus-like particle vaccines and poxvirus-based vaccines. Poxvirus-based vaccines and the chimeric yellow fever-JE vaccine have been tested in Phase I clinical trials. These new vaccines have the potential to significantly reduce the impact of JE in Asia, particularly if used in an oral vaccine delivery strategy. PMID:12903806

  16. Alteration in plasma glucose levels in Japanese encephalitis patients.

    PubMed

    Tandon, Apurva; Singh, Aditi; Atrishi, Ekta; Saxena, S K; Mathur, Asha

    2002-02-01

    A unique factor, human T cell hypoglycaemic factor (hTCHF), has been shown to produce hypoglycaemia during the convalescent stage in the plasma of patients with Japanese encephalitis virus (JEV) infection. The present study was undertaken to investigate the ability of T cells from fresh peripheral blood mononuclear cells (PBMC) of such patients to produce hTCHF. The PBMC, as well as the individual subpopulations, were cultured for 24 h and the culture supernatants (CS) were assayed for hypoglycaemic activity. The activity was observed in the CD8+ T cells. The hypoglycaemia in JE-confirmed patients coincided with the gradual rise in circulating glucagon level, with no significant alterations in insulin, growth hormone and cortisol levels. The hTCHF was purified by ion exchange chromatography and the purified protein was observed as a approximately 25 kDa band on SDS-PAGE. Secretory hTCHF in the sera of patients and T cell CS was present in 88% of convalescent serum samples. We conclude that during the convalescent stage of JEV infection, a unique factor, hTCHF, is secreted by activated CD8+ T cells from patients and that this is responsible for the development of hypoglycaemia. PMID:12059908

  17. Can Herpes Simplex Virus Encephalitis Cause Aphasia?

    ERIC Educational Resources Information Center

    Naude, H.; Pretorius, E.

    2003-01-01

    Aphasia implies the loss or impairment of language caused by brain damage. The key to understanding the nature of aphasic symptoms is the neuro-anatomical site of brain damage, and not the causative agent. However, because "Herpes simplex" virus (HSV) encephalitis infection usually affects the frontal and temporal lobes, subcortical structures and…

  18. Migrating Birds and Tickborne Encephalitis Virus

    PubMed Central

    Lundkvist, Åke; Falk, Kerstin I.; Garpmo, Ulf; Bergström, Sven; Lindegren, Gunnel; Sjöstedt, Anders; Mejlon, Hans; Fransson, Thord; Haemig, Paul D.; Olsen, Björn

    2007-01-01

    During spring and autumn 2001, we screened 13,260 migrating birds at Ottenby Bird Observatory, Sweden, and found 3.4% were infested with ticks. Four birds, each a different passerine species, carried tickborne encephalitis virus (TBEV)–infected ticks (Ixodes ricinus). Migrating birds may play a role in the geographic dispersal of TBEV-infected ticks. PMID:17953095

  19. Encephalitis

    MedlinePlus

    ... during a certain season. Encephalitis caused by the herpes simplex virus is the leading cause of more severe cases ... show: Abnormal reflexes Increased intracranial pressure Mental confusion Mouth ulcers Muscle weakness Neck stiffness Signs in other ...

  20. Encephalitis

    MedlinePlus

    ... from an infected person Contaminated food or drink Mosquito, tick, and other insect bites Skin contact Different ... with anyone who has encephalitis. Controlling mosquitoes (a mosquito bite can transmit some viruses) may reduce the ...

  1. Establishment of an Algorithm Using prM/E- and NS1-Specific IgM Antibody-Capture Enzyme-Linked Immunosorbent Assays in Diagnosis of Japanese Encephalitis Virus and West Nile Virus Infections in Humans.

    PubMed

    Galula, Jedhan U; Chang, Gwong-Jen J; Chuang, Shih-Te; Chao, Day-Yu

    2016-02-01

    The front-line assay for the presumptive serodiagnosis of acute Japanese encephalitis virus (JEV) and West Nile virus (WNV) infections is the premembrane/envelope (prM/E)-specific IgM antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA). Due to antibody cross-reactivity, MAC-ELISA-positive samples may be confirmed with a time-consuming plaque reduction neutralization test (PRNT). In the present study, we applied a previously developed anti-nonstructural protein 1 (NS1)-specific MAC-ELISA (NS1-MAC-ELISA) on archived acute-phase serum specimens from patients with confirmed JEV and WNV infections and compared the results with prM/E containing virus-like particle-specific MAC-ELISA (VLP-MAC-ELISA). Paired-receiver operating characteristic (ROC) curve analyses revealed no statistical differences in the overall assay performances of the VLP- and NS1-MAC-ELISAs. The two methods had high sensitivities of 100% but slightly lower specificities that ranged between 80% and 100%. When the NS1-MAC-ELISA was used to confirm positive results in the VLP-MAC-ELISA, the specificity of serodiagnosis, especially for JEV infection, was increased to 90% when applied in areas where JEV cocirculates with WNV, or to 100% when applied in areas that were endemic for JEV. The results also showed that using multiple antigens could resolve the cross-reactivity in the assays. Significantly higher positive-to-negative (P/N) values were consistently obtained with the homologous antigens than those with the heterologous antigens. JEV or WNV was reliably identified as the currently infecting flavivirus by a higher ratio of JEV-to-WNV P/N values or vice versa. In summary of the above-described results, the diagnostic algorithm combining the use of multiantigen VLP- and NS1-MAC-ELISAs was developed and can be practically applied to obtain a more specific and reliable result for the serodiagnosis of JEV and WNV infections without the need for PRNT. The developed algorithm should provide great

  2. Establishment of an Algorithm Using prM/E- and NS1-Specific IgM Antibody-Capture Enzyme-Linked Immunosorbent Assays in Diagnosis of Japanese Encephalitis Virus and West Nile Virus Infections in Humans

    PubMed Central

    Galula, Jedhan U.; Chang, Gwong-Jen J.

    2015-01-01

    The front-line assay for the presumptive serodiagnosis of acute Japanese encephalitis virus (JEV) and West Nile virus (WNV) infections is the premembrane/envelope (prM/E)-specific IgM antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA). Due to antibody cross-reactivity, MAC-ELISA-positive samples may be confirmed with a time-consuming plaque reduction neutralization test (PRNT). In the present study, we applied a previously developed anti-nonstructural protein 1 (NS1)-specific MAC-ELISA (NS1-MAC-ELISA) on archived acute-phase serum specimens from patients with confirmed JEV and WNV infections and compared the results with prM/E containing virus-like particle-specific MAC-ELISA (VLP-MAC-ELISA). Paired-receiver operating characteristic (ROC) curve analyses revealed no statistical differences in the overall assay performances of the VLP- and NS1-MAC-ELISAs. The two methods had high sensitivities of 100% but slightly lower specificities that ranged between 80% and 100%. When the NS1-MAC-ELISA was used to confirm positive results in the VLP-MAC-ELISA, the specificity of serodiagnosis, especially for JEV infection, was increased to 90% when applied in areas where JEV cocirculates with WNV, or to 100% when applied in areas that were endemic for JEV. The results also showed that using multiple antigens could resolve the cross-reactivity in the assays. Significantly higher positive-to-negative (P/N) values were consistently obtained with the homologous antigens than those with the heterologous antigens. JEV or WNV was reliably identified as the currently infecting flavivirus by a higher ratio of JEV-to-WNV P/N values or vice versa. In summary of the above-described results, the diagnostic algorithm combining the use of multiantigen VLP- and NS1-MAC-ELISAs was developed and can be practically applied to obtain a more specific and reliable result for the serodiagnosis of JEV and WNV infections without the need for PRNT. The developed algorithm should provide great

  3. A collaborative study of an alternative in vitro potency assay for the Japanese encephalitis vaccine.

    PubMed

    Kim, Byung-Chul; Kim, Do-Keun; Kim, Hyung-Jin; Hong, Seung-Hwa; Kim, Yeonhee; Lim, Jong-Mi; Hong, JiYoung; Kim, Cheol-Hee; Park, Yong-Keun; Kim, Jaeok

    2016-09-01

    The use of inactivated Japanese encephalitis (JE) vaccines has been ongoing in East Asia for 40 years. A mouse immunogenicity assay followed by a Plaque Reduction Neutralization (PRN) Test (PRNTest) is currently recommended for each lot release of the vaccine by many national authorities. We developed an alternative in vitro ELISA to determine the E antigen content of the Japanese encephalitis virus to observe the 3Rs strategy. A collaborative study for replacing the in vivo potency assay for the Japanese encephalitis vaccine with the in vitro ELISA assay was confirmed comparability between these two methods. The study demonstrated that an in vitro assay could perform faster and was more convenient than the established in vivo PRNTest. Moreover, this assay had better precision and reproducibility compared with the conventional in vivo assay. Additionally, the content of antigen determined using the in vitro ELISA correlated well with the potency of the in vivo assay. Furthermore, this method allowed discrimination between individual lots. Thus, we propose a progressive switch from the in vivo assay to the in vitro ELISA for JE vaccine quality control. PMID:27497622

  4. Japanese Encephalitis Vaccines: WHO position paper, February 2015--Recommendations.

    PubMed

    2016-01-12

    This article presents the World Health Organization's (WHO) recommendations on the use of Japanese Encephalitis (JE) vaccines excerpted from the WHO position paper on Japanese Encephalitis vaccines recently published in the Weekly Epidemiological Record [1]. This updated position paper on JE vaccines replaces the 2006 position paper on this subject [2]; it focuses on new information concerning the availability, safety, immunogenicity and effectiveness of JE vaccines and the duration of protection they confer. Recent data on global prevalence and burden of disease caused by JE and cost-effectiveness considerations regarding JE vaccination are also summarized. Footnotes to this paper provide a number of core references including references to grading tables that assess the quality of the scientific evidence. In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale immunization programmes; they summarize essential background information on diseases and vaccines, and conclude with WHO's current position on the use of vaccines in the global context. This paper reflects the recommendations of WHO's Strategic Advisory Group of Experts (SAGE) on immunization. These recommendations were discussed by SAGE at its October 2014 meeting. Evidence presented at the meeting can be accessed at http://www.who.int/immunization/sage/previous/en/index.html. PMID:26232543

  5. West Nile Virus Encephalitis 16 Years Later.

    PubMed

    Kleinschmidt-DeMasters, Bette K; Beckham, J David

    2015-09-01

    Arboviruses (Arthropod-borne viruses) include several families of viruses (Flaviviridae, Togaviradae, Bunyaviradae, Reoviradae) that are spread by arthropod vectors, most commonly mosquitoes, ticks and sandflies. The RNA genome allows these viruses to rapidly adapt to ever-changing host and environmental conditions. Thus, these virus families are largely responsible for the recent expansion in geographic range of emerging viruses including West Nile virus (WNV), dengue virus and Chikungunya virus. This review will focus on WNV, especially as it has progressively spread westward in North America since its introduction in New York in 1999. By 2003, WNV infections in humans had reached almost all lower 48 contiguous United States (US) and since that time, fluctuations in outbreaks have occurred. Cases decreased between 2008 and 2011, followed by a dramatic flair in 2012, with the epicenter in the Dallas-Fort Worth region of Texas. The 2012 outbreak was associated with an increase in reported neuroinvasive cases. Neuroinvasive disease continues to be a problem particularly in the elderly and immunocompromised populations, although WNV infections also represented the second most frequent cause of pediatric encephalitis in these same years. Neuropathological features in cases from the 2012 epidemic highlight the extent of viral damage that can occur in the CNS. PMID:26276026

  6. Biomarkers in Japanese Encephalitis: A Review

    PubMed Central

    Kant Upadhyay, Ravi

    2013-01-01

    JE is a flavivirus generated dreadful CNS disease which causes high mortality in various pediatric groups. JE disease is currently diagnosed by measuring the level of viral antigens and virus neutralization IgM antibodies in blood serum and CSF by ELISA. However, it is not possible to measure various disease-identifying molecules, structural and molecular changes occurred in tissues, and cells by using such routine methods. However, few important biomarkers such as cerebrospinal fluid, plasma, neuro-imaging, brain mapping, immunotyping, expression of nonstructural viral proteins, systematic mRNA profiling, DNA and protein microarrays, active caspase-3 activity, reactive oxygen species and reactive nitrogen species, levels of stress-associated signaling molecules, and proinflammatory cytokines could be used to confirm the disease at an earlier stage. These biomarkers may also help to diagnose mutant based environment specific alterations in JEV genotypes causing high pathogenesis and have immense future applications in diagnostics. There is an utmost need for the development of new more authentic, appropriate, and reliable physiological, immunological, biochemical, biophysical, molecular, and therapeutic biomarkers to confirm the disease well in time to start the clinical aid to the patients. Hence, the present review aims to discuss new emerging biomarkers that could facilitate more authentic and fast diagnosis of JE disease and its related disorders in the future. PMID:24455705

  7. Biomarkers in Japanese encephalitis: a review.

    PubMed

    Kant Upadhyay, Ravi

    2013-01-01

    JE is a flavivirus generated dreadful CNS disease which causes high mortality in various pediatric groups. JE disease is currently diagnosed by measuring the level of viral antigens and virus neutralization IgM antibodies in blood serum and CSF by ELISA. However, it is not possible to measure various disease-identifying molecules, structural and molecular changes occurred in tissues, and cells by using such routine methods. However, few important biomarkers such as cerebrospinal fluid, plasma, neuro-imaging, brain mapping, immunotyping, expression of nonstructural viral proteins, systematic mRNA profiling, DNA and protein microarrays, active caspase-3 activity, reactive oxygen species and reactive nitrogen species, levels of stress-associated signaling molecules, and proinflammatory cytokines could be used to confirm the disease at an earlier stage. These biomarkers may also help to diagnose mutant based environment specific alterations in JEV genotypes causing high pathogenesis and have immense future applications in diagnostics. There is an utmost need for the development of new more authentic, appropriate, and reliable physiological, immunological, biochemical, biophysical, molecular, and therapeutic biomarkers to confirm the disease well in time to start the clinical aid to the patients. Hence, the present review aims to discuss new emerging biomarkers that could facilitate more authentic and fast diagnosis of JE disease and its related disorders in the future. PMID:24455705

  8. Western equine encephalitis virus is a recombinant virus.

    PubMed Central

    Hahn, C S; Lustig, S; Strauss, E G; Strauss, J H

    1988-01-01

    The alphaviruses are a group of 26 mosquito-borne viruses that cause a variety of human diseases. Many of the New World alphaviruses cause encephalitis, whereas the Old World viruses more typically cause fever, rash, and arthralgia. The genome is a single-stranded nonsegmented RNA molecule of + polarity; it is about 11,700 nucleotides in length. Several alphavirus genomes have been sequenced in whole or in part, and these sequences demonstrate that alpha-viruses have descended from a common ancestor by divergent evolution. We have now obtained the sequence of the 3'-terminal 4288 nucleotides of the RNA of the New World Alphavirus western equine encephalitis virus (WEEV). Comparisons of the nucleotide and amino acid sequences of WEEV with those of other alphaviruses clearly show that WEEV is recombinant. The sequences of the capsid protein and of the (untranslated) 3'-terminal 80 nucleotides of WEEV are closely related to the corresponding sequences of the New World Alphavirus eastern equine encephalitis virus (EEEV), whereas the sequences of glycoproteins E2 and E1 of WEEV are more closely related to those of an Old World virus, Sindbis virus. Thus, WEEV appears to have arisen by recombination between an EEEV-like virus and a Sindbis-like virus to give rise to a new virus with the encephalogenic properties of EEEV but the antigenic specificity of Sindbis virus. There has been speculation that recombination might play an important role in the evolution of RNA viruses. The current finding that a widespread and successful RNA virus is recombinant provides support for such an hypothesis. Images PMID:3413072

  9. Virus meningo-encephalitis in Austria

    PubMed Central

    Verlinde, J. D.; van Tongeren, H. A. E.; Pattyn, S. R.; Rosenzweig, A.

    1955-01-01

    Two virus strains were isolated from the central nervous systems of two fatal human cases during an epidemic of encephalomyelitis in Austria. Monkeys, mice, and chick embryos proved susceptible; rabbits and guinea-pigs were refractory. The experimental disease in monkeys was characterized by acute meningo-encephalomyelitis, which was localized particularly in the grey matter of the brain stem, the cerebellum, the medulla, and the anterior horns of the spinal cord. The virus produced discrete lesions on the chorioallantoic membrane of the chick embryo. In monkeys, viraemia was demonstrated for a period of at least 6-8 days before the development of the clinical illness. The virus was shown to be closely related to that of Russian spring-summer encephalitis. Neutralizing and complement-fixing antibodies could be demonstrated in patients' sera. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7FIG. 8FIG. 9FIG. 10FIG. 11FIG. 12 PMID:14378999

  10. CD4+ T cells provide protection against acute lethal encephalitis caused by Venezuelan equine encephalitis virus

    PubMed Central

    Yun, Nadezhda E.; Peng, Bi-Hung; Bertke, Andrea S.; Borisevich, Viktoriya; Smith, Jennifer K.; Smith, Jeanon N.; Poussard, Allison L.; Salazar, Milagros; Judy, Barbara M.; Zacks, Michele A.; Estes, D. Mark; Paessler, Slobodan

    2009-01-01

    Studying the mechanisms of host survival resulting from viral encephalitis is critical to the development of vaccines. Here we have shown in several independent studies that high-dose treatment with neutralizing antibody prior to intranasal infection with Venezuelan equine encephalitis virus had an antiviral effect in the visceral organs and prolonged survival time of infected mice, even in the absence of alpha beta T cells. Nevertheless, the antibody treatment did not prevent the development of lethal encephalitis. In contrary, the adoptive transfer of primed CD4+ T cells is necessary to prevent lethal encephalitis in mice lacking alpha beta T cell receptor. PMID:19446933

  11. Surveillance for Western Equine Encephalitis, St. Louis Encephalitis, and West Nile Viruses Using Reverse Transcription Loop-Mediated Isothermal Amplification.

    PubMed

    Wheeler, Sarah S; Ball, Cameron S; Langevin, Stanley A; Fang, Ying; Coffey, Lark L; Meagher, Robert J

    2016-01-01

    Collection of mosquitoes and testing for vector-borne viruses is a key surveillance activity that directly influences the vector control efforts of public health agencies, including determining when and where to apply insecticides. Vector control districts in California routinely monitor for three human pathogenic viruses including West Nile virus (WNV), Western equine encephalitis virus (WEEV), and St. Louis encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires costly, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonstructural protein 4 (nsP4) gene of WEEV and the 3' untranslated region (3'-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of <0.1 PFU/reaction of their respective targets in <30 minutes, and exhibited high specificity without cross reactivity when tested against a panel of alphaviruses and flaviviruses. Furthermore, the SLEV primers do not cross-react with WNV, despite both viruses being closely related members of the Japanese encephalitis virus complex. The SLEV and WEEV primers can also be combined in a single RT-LAMP reaction, with discrimination between amplicons by melt curve analysis. Although RT-qPCR is approximately one order of magnitude more sensitive than RT-LAMP for all three targets, the RT-LAMP technique is less instrumentally intensive than RT-qPCR and provides a more cost-effective method of vector-borne virus surveillance. PMID:26807734

  12. Surveillance for Western equine encephalitis St. Louis encephalitis and West Nile viruses using reverse transcription loop-mediated isothermal amplification

    DOE PAGESBeta

    Meagher, Robert J.; Ball, Cameron Scott; Langevin, Stanley A.; Fang, Ying; Wheeler, Sarah S.; Coffey, Lark L.

    2016-01-25

    In this study, collection of mosquitoes and testing for vector-borne viruses is a key surveillance activity that directly influences the vector control efforts of public health agencies, including determining when and where to apply insecticides. Vector control districts in California routinely monitor for three human pathogenic viruses including West Nile virus (WNV), Western equine encephalitis virus (WEEV), and St. Louis encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires costly, specialized equipment that is generally only available in centralized publicmore » health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonstructural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of <0.1 PFU/reaction of their respective targets in <30 minutes, and exhibited high specificity without cross reactivity when tested against a panel of alphaviruses and flaviviruses. Furthermore, the SLEV primers do not cross-react with WNV, despite both viruses being closely related members of the Japanese encephalitis virus complex. The SLEV and WEEV primers can also be combined in a single RT-LAMP reaction, with discrimination between amplicons by melt curve analysis. Although RT-qPCR is approximately one order of magnitude more sensitive than RT-LAMP for all three targets, the RT-LAMP technique is less instrumentally intensive than RT-qPCR and provides a more cost-effective method of vector-borne virus surveillance.« less

  13. Surveillance for Western Equine Encephalitis, St. Louis Encephalitis, and West Nile Viruses Using Reverse Transcription Loop-Mediated Isothermal Amplification

    PubMed Central

    Wheeler, Sarah S.; Ball, Cameron S.; Langevin, Stanley A.; Fang, Ying; Coffey, Lark L.; Meagher, Robert J.

    2016-01-01

    Collection of mosquitoes and testing for vector-borne viruses is a key surveillance activity that directly influences the vector control efforts of public health agencies, including determining when and where to apply insecticides. Vector control districts in California routinely monitor for three human pathogenic viruses including West Nile virus (WNV), Western equine encephalitis virus (WEEV), and St. Louis encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires costly, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonstructural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of <0.1 PFU/reaction of their respective targets in <30 minutes, and exhibited high specificity without cross reactivity when tested against a panel of alphaviruses and flaviviruses. Furthermore, the SLEV primers do not cross-react with WNV, despite both viruses being closely related members of the Japanese encephalitis virus complex. The SLEV and WEEV primers can also be combined in a single RT-LAMP reaction, with discrimination between amplicons by melt curve analysis. Although RT-qPCR is approximately one order of magnitude more sensitive than RT-LAMP for all three targets, the RT-LAMP technique is less instrumentally intensive than RT-qPCR and provides a more cost-effective method of vector-borne virus surveillance. PMID:26807734

  14. Astrocyte response to St. Louis encephalitis virus.

    PubMed

    Zuza, Adriano Lara; Barros, Heber Leão Silva; de Mattos Silva Oliveira, Thelma Fátima; Chávez-Pavoni, Juliana Helena; Zanon, Renata Graciele

    2016-06-01

    St. Louis encephalitis virus (SLEV), a flavivirus transmitted to humans by Culex mosquitoes, causes clinical symptoms ranging from acute febrile disorder to encephalitis. To reach the central nervous system (CNS) from circulating blood, the pathogen must cross the blood-brain barrier formed by endothelial cells and astrocytes. Because astrocytes play an essential role in CNS homeostasis, in this study these cells were infected with SLEV and investigated for astrogliosis, major histocompatibility complex (MHC)-I-dependent immune response, and apoptosis by caspase-3 activation. Cultures of Vero cells were used as a positive control for the viral infection. Cytopathic effects were observed in both types of cell cultures, and the cytotoxicity levels of the two were compared. Astrocytes infected with a dilution of 1E-01 (7.7E+08 PFU/mL) had a reduced mortality rate of more than 50% compared to the Vero cells. In addition, the astrocytes responded to the flavivirus infection with increased MHC-I expression and astrogliosis, characterized by intense glial fibrillary acidic protein expression and an increase in the number and length of cytoplasmic processes. When the astrocytes were exposed to higher viral concentrations, a proportional increase in caspase-3 expression was observed, as well as nuclear membrane destruction. SLEV immunostaining revealed a perinuclear location of the virus during the replication process. Together, these results suggest that mechanisms other than SLEV infection in astrocytes must be associated with the development of the neuroinvasive form of the disease. PMID:26975980

  15. Venezuelan Equine Encephalitis Virus, Southern Mexico

    PubMed Central

    Estrada-Franco, José G.; Navarro-Lopez, Roberto; Freier, Jerome E.; Cordova, Dionicio; Clements, Tamara; Moncayo, Abelardo; Kang, Wenli; Gomez-Hernandez, Carlos; Rodriguez-Dominguez, Gabriela; Ludwig, George V.

    2004-01-01

    Equine epizootics of Venezuelan equine encephalitis (VEE) occurred in the southern Mexican states of Chiapas in 1993 and Oaxaca in 1996. To assess the impact of continuing circulation of VEE virus (VEEV) on human and animal populations, serologic and viral isolation studies were conducted in 2000 to 2001 in Chiapas State. Human serosurveys and risk analyses indicated that long-term endemic transmission of VEEV occurred among villages with seroprevalence levels of 18% to 75% and that medical personnel had a high risk for VEEV exposure. Seroprevalence in wild animals suggested cotton rats as possible reservoir hosts in the region. Virus isolations from sentinel animals and genetic characterizations of these strains indicated continuing circulation of a subtype IE genotype, which was isolated from equines during the recent VEE outbreaks. These data indicate long-term enzootic and endemic VEEV circulation in the region and continued risk for disease in equines and humans. PMID:15663847

  16. Development of an in vitro antigen-detection test as an alternative method to the in vivo plaque reduction neutralization test for the quality control of Japanese encephalitis virus vaccine.

    PubMed

    Kim, Do Keun; Kim, Hye-Youn; Kim, Joo-Young; Ye, Michael B; Park, Kee-Bum; Han, Euiri; Kim, Jaeok; Ja Ban, Sang; Hong, Seung Hwa; Park, Yong Keun; Nam, Jae-Hwan

    2012-07-01

    Japanese encephalitis virus (JEV) causes diseases that attack the human central nervous system. Traditionally, the quality control for JEV vaccines, in which the plaque reduction neutralization (PRN) titer is measured by the national control laboratories before the vaccine batches are marketed, has required laboratory animal testing. However, classical animal tests have inherent problems, including the very fact that animals are used, ethical issues, and the possibility of error. In this study, JEV antigen was measured in an in vitro assay to assess the feasibility of replacing in vivo assays that measure the PRN titers of JEV vaccines. We constructed a double-sandwich enzyme-linked immunosorbent assay (DS-ELISA) that could detect JEV envelope (E). Initially, monoclonal antibodies (mAbs) directed against the JEV E protein were generated and characterized. We isolated 18 mAbs against JEV E protein, and most were the IgG1 or IgG2a isotype. The mAbs (5F15 and 7D71) were selected as the most suitable mAb pair to detect JEV E protein. DS-ELISA with this pair detected as little as approximately 3 μg/mL JEV E protein and demonstrated a relationship between the amount of JEV E protein and the PRN titer. From these results, we surmise that this DS-ELISA may be useful, not only in terms of measuring the amount of JEV E protein, but also as a substitute for the PRN test for JEV vaccine evaluation. PMID:22486472

  17. Japanese encephalitis virus induces matrix metalloproteinase-9 expression via a ROS/c-Src/PDGFR/PI3K/Akt/MAPKs-dependent AP-1 pathway in rat brain astrocytes

    PubMed Central

    2012-01-01

    Background Japanese encephalitis virus (JEV) infection is a major cause of acute encephalopathy in children, which destroys central nervous system (CNS) cells, including astrocytes and neurons. Matrix metalloproteinase (MMP)-9 has been shown to degrade components of the basal lamina, leading to disruption of the blood-brain barrier (BBB) and to contribute to neuroinflammatory responses in many neurological diseases. However, the detailed mechanisms of JEV-induced MMP-9 expression in rat brain astrocytes (RBA-1 cells) are largely unclear. Methods In this study, the effect of JEV on expression of MMP-9 was determined by gelatin zymography, western blot analysis, RT-PCR, and promoter assay. The involvement of AP-1 (c-Jun and c-Fos), c-Src, PDGFR, PI3K/Akt, and MAPKs in these responses were investigated by using the selective pharmacological inhibitors and transfection with siRNAs. Results Here, we demonstrate that JEV induces expression of pro-form MMP-9 via ROS/c-Src/PDGFR/PI3K/Akt/MAPKs-dependent, AP-1 activation in RBA-1 cells. JEV-induced MMP-9 expression and promoter activity were inhibited by pretreatment with inhibitors of AP-1 (tanshinone), c-Src (PP1), PDGFR (AG1296), and PI3K (LY294002), and by transfection with siRNAs of c-Jun, c-Fos, PDGFR, and Akt. Moreover, JEV-stimulated AP-1 activation was inhibited by pretreatment with the inhibitors of c-Src, PDGFR, PI3K, and MAPKs. Conclusion From these results, we conclude that JEV activates the ROS/c-Src/PDGFR/PI3K/Akt/MAPKs pathway, which in turn triggers AP-1 activation and ultimately induces MMP-9 expression in RBA-1 cells. These findings concerning JEV-induced MMP-9 expression in RBA-1 cells imply that JEV might play an important role in CNS inflammation and diseases. PMID:22251375

  18. A Case Series of Three US Adults with Japanese Encephalitis, 2010-2012

    PubMed Central

    Hills, Susan L.; Stoltey, Juliet; Martínez, Diana; Kim, Paul Y.; Sheriff, Heather; Zangeneh, Ana; Eilerman, Sally R.; Fischer, Marc

    2015-01-01

    Background Japanese encephalitis (JE) virus is the leading vaccine-preventable cause of encephalitis in Asia. Although the risk for JE for most travelers to Asia is low, it varies based on the destination, season, trip duration, and activities. Methods We present case reports for three US adults who were infected with JE virus while traveling or residing in Asia. Results Among the three JE cases, one case had a 10-day trip to mainland China and participated in outdoor activities in a rural area, a second case had been resident in Taiwan for 4 months, and a third, fatal case was an expatriate living in South Korea. Conclusions JE should be considered in the differential diagnosis for any patient with an acute neurologic infection who recently has been in a JE-endemic country. Health-care providers should assess the itineraries of travelers to JE-endemic countries, provide guidance on personal protective measures to prevent vector-borne diseases, and consider recommending JE vaccine for travelers at increased risk for JE virus infection. PMID:24861145

  19. Fatal West Nile Virus Encephalitis in a Heart Transplant Recipient

    PubMed Central

    Gomez, Adam J.; Waggoner, Jesse J.; Itoh, Megumi; Hollander, Seth A.; Gutierrez, Kathleen M.; Budvytiene, Indre; Banaei, Niaz

    2015-01-01

    The diagnosis of encephalitis is particularly challenging in immunocompromised patients. We report here a case of fatal West Nile virus encephalitis confounded by the presence of budding yeast in the cerebrospinal fluid (CSF) from a patient who had undergone heart transplantation for dilated cardiomyopathy 11 months prior to presentation of neurologic symptoms. PMID:25994169

  20. Profiling of Viral Proteins Expressed from the Genomic RNA of Japanese Encephalitis Virus Using a Panel of 15 Region-Specific Polyclonal Rabbit Antisera: Implications for Viral Gene Expression

    PubMed Central

    Yun, Sang-Im; Yun, Gil-Nam; Byun, Sung-June; Lee, Young-Min

    2015-01-01

    Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, is closely related to West Nile (WN), yellow fever (YF), and dengue (DEN) viruses. Its plus-strand genomic RNA carries a single open reading frame encoding a polyprotein that is cleaved into three structural (C, prM/M, and E) and at least seven nonstructural (NS1/NS1', NS2A, NS2B, NS3, NS4A, NS4B, and NS5) proteins, based on previous work with WNV, YFV, and DENV. Here, we aimed to profile experimentally all the viral proteins found in JEV-infected cells. We generated a collection of 15 JEV-specific polyclonal antisera covering all parts of the viral protein-coding regions, by immunizing rabbits with 14 bacterially expressed glutathione-S-transferase fusion proteins (for all nine viral proteins except NS2B) or with a chemically synthesized oligopeptide (for NS2B). In total lysates of JEV-infected BHK-21 cells, immunoblotting with these antisera revealed: (i) three mature structural proteins (~12-kDa C, ~8-kDa M, and ~53-kDa E), a precursor of M (~24-kDa prM) and three other M-related proteins (~10-14 kDa); (ii) the predicted ~45-kDa NS1 and its frameshift product, ~58-kDa NS1', with no evidence of the predicted ~25-kDa NS2A; (iii) the predicted but hardly detectable ~14-kDa NS2B and an unexpected but predominant ~12-kDa NS2B-related protein; (iv) the predicted ~69-kDa NS3 plus two major cleavage products (~34-kDa NS3N-term and ~35-kDa NS3C-term), together with at least nine minor proteins of ~16-52 kDa; (v) the predicted ~14-kDa NS4A; (vi) two NS4B-related proteins (~27-kDa NS4B and ~25-kDa NS4B'); and (vii) the predicted ~103-kDa NS5 plus at least three other NS5-related proteins (~15 kDa, ~27 kDa, and ~90 kDa). Combining these data with confocal microscopic imaging of the proteins’ intracellular localization, our study is the first to provide a solid foundation for the study of JEV gene expression, which is crucial for elucidating the regulatory mechanisms of JEV genome replication and pathobiology

  1. Japanese encephalitis surveillance and immunization--Asia and the Western Pacific, 2012.

    PubMed

    2013-08-23

    Japanese encephalitis (JE) virus is a leading cause of encephalitis in Asia, causing an estimated 67,900 JE cases annually. To control JE, the World Health Organization (WHO) recommends that JE vaccine be incorporated into immunization programs in all areas where JE is a public health problem. For many decades, progress mainly occurred in a small number of high-income Asian countries. Recently, prospects for control have improved with better disease burden awareness as a result of increased JE surveillance and wider availability of safe, effective vaccines. This report summarizes the status of JE surveillance and immunization programs in 2012 in Asia and the Western Pacific. Data were obtained from the WHO/United Nations Children's Fund (UNICEF) Joint Reporting Form (JRF), published literature, meeting reports, and websites. In 2012, 18 (75%) of the 24 countries with areas of JE virus transmission risk conducted at least some JE surveillance, and 11 (46%) had a JE immunization program. Further progress toward JE control requires increased awareness of disease burden at the national and regional levels, availability of WHO-prequalified pediatric JE vaccines, and international support for surveillance and vaccine introduction in countries with limited resources. PMID:23965828

  2. A randomized study of the immunogenicity and safety of Japanese Encephalitis Chimeric Virus Vaccine (JE-CV) in comparison with SA14-14-2 Vaccine in children in the Republic of Korea

    PubMed Central

    Kim, Dong Soo; Houillon, Guy; Jang, Gwang Cheon; Cha, Sung-Ho; Choi, Soo-Han; Lee, Jin; Kim, Hwang Min; Kim, Ji Hong; Kang, Jin Han; Kim, Jong-Hyun; Kim, Ki Hwan; Kim, Hee Soo; Bang, Joon; Naimi, Zulaikha; Bosch-Castells, Valérie; Boaz, Mark; Bouckenooghe, Alain

    2014-01-01

    A new live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) has been developed based on innovative technology to give protection against JE with an improved immunogenicity and safety profile. In this phase 3, observer-blind study, 274 children aged 12−24 months were randomized 1:1 to receive one dose of JE-CV (Group JE-CV) or the SA14–14–2 vaccine currently used to vaccinate against JE in the Republic of Korea (Group SA14–14–2). JE neutralizing antibody titers were assessed using PRNT50 before and 28 days after vaccination. The primary endpoint of non-inferiority of seroconversion rates on D28 was demonstrated in the Per Protocol analysis set as the difference between Group JE-CV and Group SA14–14–2 was 0.9 percentage points (95% confidence interval [CI]: −2.35; 4.68), which was above the required −10%. Seroconversion and seroprotection rates 28 days after administration of a single vaccine dose were 100% in Group JE-CV and 99.1% in Group SA14–14–2; all children except one (Group SA14–14–2) were seroprotected. Geometric mean titers (GMTs) increased in both groups from D0 to D28; GM of titer ratios were slightly higher in Group JE-CV (182 [95% CI: 131; 251]) than Group SA14–14–2 (116 [95% CI: 85.5, 157]). A single dose of JE-CV was well tolerated and no safety concerns were identified. In conclusion, a single dose of JE-CV or SA14–14–2 vaccine elicited a comparable immune response with a good safety profile. Results obtained in healthy Korean children aged 12−24 months vaccinated with JE-CV are consistent with those obtained in previous studies conducted with JE-CV in toddlers. PMID:25483480

  3. Molecular identification of Saint Louis encephalitis virus genotype IV in Colombia

    PubMed Central

    Hoyos-López, Richard; Soto, Sandra Uribe; Rúa-Uribe, Guillermo; Gallego-Gómez, Juan Carlos

    2015-01-01

    Saint Louis encephalitis virus (SLEV) is a member of the Japanese-encephalitis virus serocomplex of the genus Flavivirus. SLEV is broadly distributed in the Americas and the Caribbean Islands, where it is usually transmitted by mosquitoes of the genus Culex and primarily to birds and mammalian-hosts. Humans are occasionally infected by the virus and are dead-end hosts. SLEV causes encephalitis in temperate regions, while in tropical regions of the Americas, several human cases and a wide biological diversity of SLEV-strains have been reported. The phylogenetic analysis of the envelope (E) protein genes indicated eight-genotypes of SLEV with geographic overlap. The present paper describes the genotyping of two SLEV viruses detected in mosquito-pools collected in northern Colombia (department of Cordoba). We used reverse transcription-polymerase chain reaction to amplify a fragment of theE-gene to confirm the virus identity and completeE-gene sequencing for phylogenetic analysis and genotyping of the two-SLEV viruses found circulating in Córdoba. This is the first report of SLEV genotype IV in Colombia (Córdoba) in mosquitoes from a region of human inhabitation, implicating the risk of human disease due to SLEV infection. Physicians should consider SLEV as a possible aetiology for undiagnosed febrile and neurologic syndromes among their patients who report exposure to mosquito-bites. PMID:26313538

  4. An outbreak of Japanese encephalitis after two decades in Odisha, India.

    PubMed

    Dwibedi, Bhagirathi; Mohapatra, Namita; Rathore, Sushil Kumar; Panda, Maheswar; Pati, Satya Sundar; Sabat, Jyotsnamayee; Thakur, Bandana; Panda, Sailendra; Kar, Shantanu Kumar

    2015-12-01

    Sudden deaths in children due to acute encephalitis syndrome (AES) from a tribal dominated district of Malkangiri in Odisha, India, was reported during September-November, 2012. The investigation was carried out to search for the possible viral aetiology that caused this outbreak. Clinico-epidemiological survey and seromolecular investigation were carried out to confirm the viral aetiology. Two hundred seventy two suspected cases with 24 deaths were observed. The patients presented with low to moderate grade fever (87%), headache (43%), vomiting (27%), cold (18%), cough (17%), body ache (15%), joint pain (15%), rash (15%), abdomen pain (9%), lethargy (5%), altered sensorium (8%), convulsion (2%), diarrhoea (3%), and haematemesis (3%). Laboratory investigation showed Japanese encephalitis virus (JEV) IgM in 13.8 per cent (13/94) in blood samples and JEV RNA in one of two cerebrospinal fluid (CSF) samples. Paddy fields close to the houses, high pig to cattle ratio, high density (33 per man hour density) of Culex vishnui mosquitoes, low socio-economic status and low health awareness in the tribal population were observed. This report confirmed the outbreak of JEV infection in Odisha after two decades. PMID:26905239

  5. The Potential Use of Wolbachia-Based Mosquito Biocontrol Strategies for Japanese Encephalitis.

    PubMed

    Jeffries, Claire L; Walker, Thomas

    2015-01-01

    Japanese encephalitis virus (JEV) is a zoonotic pathogen transmitted by the infectious bite of Culex mosquitoes. The virus causes the development of the disease Japanese encephalitis (JE) in a small proportion of those infected, predominantly affecting children in eastern and southern Asia. Annual JE incidence estimates range from 50,000-175,000, with 25%-30% of cases resulting in mortality. It is estimated that 3 billion people live in countries in which JEV is endemic. The virus exists in an enzootic transmission cycle, with mosquitoes transmitting JEV between birds as reservoir hosts and pigs as amplifying hosts. Zoonotic infection occurs as a result of spillover events from the main transmission cycle. The reservoir avian hosts include cattle egrets, pond herons, and other species of water birds belonging to the family Ardeidae. Irrigated rice fields provide an ideal breeding ground for mosquitoes and attract migratory birds, maintaining the transmission of JEV. Although multiple vaccines have been developed for JEV, they are expensive and require multiple doses to maintain efficacy and immunity. As humans are a "dead-end" host for the virus, vaccination of the human population is unlikely to result in eradication. Therefore, vector control of the principal mosquito vector, Culex tritaeniorhynchus, represents a more promising strategy for reducing transmission. Current vector control strategies include intermittent irrigation of rice fields and space spraying of insecticides during outbreaks. However, Cx. Tritaeniorhynchus is subject to heavy exposure to pesticides in rice fields, and as a result, insecticide resistance has developed. In recent years, significant advancements have been made in the potential use of the bacterial endosymbiont Wolbachia for mosquito biocontrol. The successful transinfection of Wolbachia strains from Drosophila flies to Aedes (Stegomyia) mosquitoes has resulted in the generation of "dengue-refractory" mosquito lines. The successful

  6. The Potential Use of Wolbachia-Based Mosquito Biocontrol Strategies for Japanese Encephalitis

    PubMed Central

    Jeffries, Claire L.; Walker, Thomas

    2015-01-01

    Japanese encephalitis virus (JEV) is a zoonotic pathogen transmitted by the infectious bite of Culex mosquitoes. The virus causes the development of the disease Japanese encephalitis (JE) in a small proportion of those infected, predominantly affecting children in eastern and southern Asia. Annual JE incidence estimates range from 50,000–175,000, with 25%–30% of cases resulting in mortality. It is estimated that 3 billion people live in countries in which JEV is endemic. The virus exists in an enzootic transmission cycle, with mosquitoes transmitting JEV between birds as reservoir hosts and pigs as amplifying hosts. Zoonotic infection occurs as a result of spillover events from the main transmission cycle. The reservoir avian hosts include cattle egrets, pond herons, and other species of water birds belonging to the family Ardeidae. Irrigated rice fields provide an ideal breeding ground for mosquitoes and attract migratory birds, maintaining the transmission of JEV. Although multiple vaccines have been developed for JEV, they are expensive and require multiple doses to maintain efficacy and immunity. As humans are a “dead-end” host for the virus, vaccination of the human population is unlikely to result in eradication. Therefore, vector control of the principal mosquito vector, Culex tritaeniorhynchus, represents a more promising strategy for reducing transmission. Current vector control strategies include intermittent irrigation of rice fields and space spraying of insecticides during outbreaks. However, Cx. Tritaeniorhynchus is subject to heavy exposure to pesticides in rice fields, and as a result, insecticide resistance has developed. In recent years, significant advancements have been made in the potential use of the bacterial endosymbiont Wolbachia for mosquito biocontrol. The successful transinfection of Wolbachia strains from Drosophila flies to Aedes (Stegomyia) mosquitoes has resulted in the generation of “dengue-refractory” mosquito lines

  7. Sero-Molecular Epidemiology of Japanese Encephalitis in Zhejiang, an Eastern Province of China

    PubMed Central

    Yan, Ju-ying; Zhou, Jia-yue; Tang, Xue-wen; He, Han-qing; Xie, Rong-hui; Mao, Hai-yan; Zhang, Yan-jun; Xie, Shu-yun

    2016-01-01

    Background Sporadic Japanese encephalitis (JE) cases still have been reported in Zhejiang Province in recent years, and concerns about vaccine cross-protection and population-level immunity have been raised off and on within the public health sphere. Genotype I (GI) has replaced GIII as the dominant genotype in Asian countries during the past few decades, which caused considerable concerns about the potential change of epidemiology characteristics and the vaccine effectiveness. The aim of this study was to investigate the prevalence of JE neutralizing antibody and its waning antibody trend after live attenuated JE vaccine immunization. Additionally, this study analyzed the molecular characteristics of the E gene of Zhejiang Japanese encephalitis virus (JEV) strains, and established genetic relationships with other JEV strains. Methodology/Principal Findings A total of 570 serum specimens were sampled from community population aged from 0 to 92 years old in Xianju county of Zhejiang Province in 2013–2014. Microseroneutralization test results were analyzed to estimate the population immunity and to observe antibody dynamics in vaccinated children. E genes of 28 JEV strains isolated in Zhejiang Province were sequenced for phylogenetic tree construction and molecular characteristics analysis with other selected strains. Positive JE neutralizing antibody rates were higher in residents ≥35 years old (81%~98%) and lower in residents <35 years old (0~57%). 7 or 8 years after the 2nd live attenuated vaccine dose, the antibodies against for 4 different strains with microseroneutralization test were decreased by 55%~73% on seropositive rates and by 25%~38% on GMTs respectively. JEV strains isolated in recent years were all grouped into GI, while those isolated in the 1980s belonged to GIII. On important amino acid sites related to antigenicity, there was no divergence between the Zhejiang JE virus strains and the vaccine strain (SA14-14-2). Conclusion/Significances JE

  8. Role of amphotericin B upon enhancement of protective immunity elicited by oral administration with liposome-encapsulated-Japanese encephalitis virus nonstructural protein 1 (NS1) in mice.

    PubMed

    Lin, Tsung-Shun; Chuang, Chuan-Chang; Hsu, Hui-Ling; Liu, Yu-Tien; Lin, Wen-Po; Liang, Chung-Chih; Liu, Wen-Tssann

    2010-09-01

    Amphotericin B (AmB) is an antifungal antibiotic the activity of which has been associated with modulation of pro-inflammatory cytokines expression in cultured cells. Herein we reveal that co-administration with AmB enhances the immunogenicity of oral Lip-JENS1 vaccine which derived from liposomes functionalized with DSPC (distearoylphosphatidylcholine) and cholesterol (2:1, molar ratio)-bearing JE virus NS1 protein (600 microg ml(-1)). Oral single dose of Lip-JENS1 elicited a detectable serum NS1-specific IgG antibody response from a mouse model. Remarkably, the addition of AmB (125 microg per mouse), particularly, 2 h prior to, but not simultaneously with, the administration of Lip-JENS1 significantly enhanced the systemic antigen-specific antibody response, providing superior protection against lethal JEV challenges. Further, we observed AmB-induced the transcription of cytokine expression and translocation of transcriptional factor NF-kappaB from the cytoplasm to the nucleus for the murine macrophage J774A.1. Moreover, Peyer's-patch lymphocytes (PPL) from AmB-treated mice produced high levels of IL-1beta, IL-6 and TNF-alpha expression compared to the corresponding control of cells from non-treated mice. Taken together, the results suggest that AmB exerts a profound influence upon mucosal vaccination with Lip-JENS1, possibly playing an adjuvant-augmented role to "fine-tune" humoral as well as cellular immune response, thus conferring enhanced protective immunity for immunising individuals against JE infection. PMID:20412849

  9. Toscana virus encephalitis following a holiday in Sicily.

    PubMed

    Osborne, Jane C; Khatamzas, Elham; Misbahuddin, Anjum; Hart, Rachel; Sivaramakrishnan, Anand; Breen, David P

    2016-04-01

    We report a case of Toscana virus encephalitis. This emerging pathogen is among the three most common causes of meningoencephalitis in Europe during the warm season, yet remains under-recognised. Doctors should consider Toscana virus infection in patients presenting with neurological symptoms who have a relevant exposure history during the summer months. PMID:26647398

  10. West Nile Virus Encephalitis in a Barbary Macaque (Macaca sylvanus)

    PubMed Central

    Barker, Ian K.; Crawshaw, Graham J.; Bertelsen, Mads F.; Drebot, Michael A.; Andonova, Maya

    2004-01-01

    An aged Barbary ape (Macaca sylvanus) at the Toronto Zoo became infected with naturally acquired West Nile virus (WNV) encephalitis that caused neurologic signs, which, associated with other medical problems, led to euthanasia. The diagnosis was based on immunohistochemical assay of brain lesions, reverse transcriptase–polymerase chain reaction, and virus isolation. PMID:15200866

  11. [Acute encephalitis. Neuropsychiatric manifestations as expression of influenza virus infection].

    PubMed

    Moreno-Flagge, Noris; Bayard, Vicente; Quirós, Evelia; Alonso, Tomás

    2009-01-01

    The aim is to review the encephalitis in infants and adolescents as well as its etiology, clinical manifestation, epidemiology, physiopathology, diagnostic methods and treatment, and the neuropsyquiatric signs appearing an influenza epidemy. Encephalitis is an inflammation of the central nervous system (CNS) which involves the brain. The clinical manifestations usually are: headache, fever and confusional stage. It could also be manifested as seizures, personality changes, or psiqyiatric symptoms. The clinical manifestations are related to the virus and the cell type affected in the brain. A meningitis or encephalopathy need to be ruled out. It could be present as an epidemic or isolated form, beeing this the most frequent form. It could be produced by a great variety of infections agents including virus, bacterias, fungal and parasitic. Viral causes are herpesvirus, arbovirus, rabies and enterovirus. Bacterias such as Borrelia burgdorferi, Rickettsia and Mycoplasma neumoniae. Some fungal causes are: Coccidioides immitis and Histoplasma capsulatum. More than 100 agents are related to encephalitis. The diagnosis of encephalitis is a challenge for the clinician and its infectious etiology is clear in only 40 to 70% of all cases. The diagnosis of encephalitis can be established with absolute certainty only by the microscopic examination of brain tissue. Epidemiology is related to age of the patients, geographic area, season, weather or the host immune system. Early intervention can reduce the mortality rate and sequels. We describe four patients with encephalitis and neuropsychiatric symptoms during an influenza epidemic. PMID:19240010

  12. A spatial and temporal analysis of Japanese encephalitis in mainland China, 1963-1975: a period without Japanese encephalitis vaccination.

    PubMed

    Li, Xiaolong; Gao, Xiaoyan; Ren, Zhoupeng; Cao, Yuxi; Wang, Jinfeng; Liang, Guodong

    2014-01-01

    More than a million Japanese encephalitis (JE) cases occurred in mainland China from the 1960s to 1970s without vaccine interventions. The aim of this study is to analyze the spatial and temporal pattern of JE cases reported in mainland China from 1965 to 1973 in the absence of JE vaccination, and to discuss the impacts of climatic and geographical factors on JE during that period. Thus, the data of reported JE cases at provincial level and monthly precipitation and monthly mean temperature from 1963 to 1975 in mainland China were collected. Local Indicators of Spatial Association analysis was performed to identify spatial clusters at the province level. During that period, The epidemic peaked in 1966 and 1971 and the JE incidence reached up to 20.58/100000 and 20.92/100000, respectively. The endemic regions can be divided into three classes including high, medium, and low prevalence regions. Through spatial cluster analysis, JE epidemic hot spots were identified; most were located in the Yangtze River Plain which lies in the southeast of China. In addition, JE incidence was shown to vary among eight geomorphic units in China. Also, the JE incidence in the Loess Plateau and the North China Plain was showed to increase with the rise of temperature. Likewise, JE incidence in the Loess Plateau and the Yangtze River Plain was observed a same trend with the increase of rainfall. In conclusion, the JE cases clustered geographically during the epidemic period. Besides, the JE incidence was markedly higher on the plains than plateaus. These results may provide an insight into the epidemiological characteristics of JE in the absence of vaccine interventions and assist health authorities, both in China and potentially in Europe and Americas, in JE prevention and control strategies. PMID:24911168

  13. A preliminary neuropathological study of Japanese encephalitis in humans and a mouse model.

    PubMed

    German, Allison C; Myint, Khin Saw Aye; Mai, Nguyen Thi Hoang; Pomeroy, Ian; Phu, Nguyen Hoan; Tzartos, John; Winter, Peter; Collett, Jennifer; Farrar, Jeremy; Barrett, Alan; Kipar, Anja; Esiri, Margaret M; Solomon, Tom

    2006-12-01

    Japanese encephalitis virus is a mosquito-borne flavivirus that causes approximately 10000 deaths annually in Asia. After a brief viraemia, the virus enters the central nervous system, but the means of crossing the blood-brain barrier is uncertain. We used routine histological staining, immunohistology and electron microscopy to examine brain material from four fatal human cases, and made comparisons with material from a mouse model. In human material there was oedema, perivascular inflammation, haemorrhage, microglial nodules and acellular necrotic foci, as has been described previously. In addition, there was new evidence suggestive of viral replication in the vascular endothelium, with endothelial cell damage; this included occasional viral antigen staining, uneven binding of the vascular endothelial cells to Ulex europaeus agglutinin I and ultrastructural changes. Viral antigen was also found in neurons. There was an active astrocytic response, as shown by glial fibrillary acidic protein staining, and activation of microglial cells was demonstrated by an increase in major histocompatibility complex class II expression. Similar inflammatory infiltrates and a microglial reaction were observed in mouse brain tissue. In addition, beta-amyloid precursor protein staining indicated impaired axonal transport. Whether these findings are caused by viral replication in the vascular endothelium or the immune response merits further investigation. PMID:16814333

  14. A KDEL Retrieval System for ER-Golgi Transport of Japanese Encephalitis Viral Particles

    PubMed Central

    Wang, Robert YL; Wu, Yu-Jen; Chen, Han-Shan; Chen, Chih-Jung

    2016-01-01

    Evidence has emerged that RNA viruses utilize the host secretory pathway for processing and trafficking mature viral particles and for exiting the infected cells. Upon completing the complex assembly process, the viral particles take advantage of the cellular secretory trafficking machinery for their intracellular trafficking toward the Golgi organelle and budding or export of virions. In this study, we showed that Japanese encephalitis virus (JEV)-induced extracellular GRP78 contains no KDEL motif using an anti-KDEL-specific antibody. Overexpression of the KDEL-truncated GRP78 in the GPR78 knocked down cells significantly reduced JEV infectivity, suggesting that the KDEL motif is required for GRP78 function in the release of JE viral particles. In addition, we demonstrated the KDELR protein, an ER-Golgi retrieval system component, is associated with viral envelope proteins and is engaged in the subcellular localization of viral particles in Golgi. More importantly, accumulation of intracellular virions was observed in the KDELR knocked down cells, indicating that the KDELR protein mediated the intracellular trafficking of JE viral particles. Altogether, we demonstrated that intracellular trafficking of JE assembled viral particles was mediated by the host ER-Golgi retrieval system prior to exit by the secretory pathway. PMID:26861384

  15. Isolation of Genotype V St. Louis Encephalitis Virus in Florida

    PubMed Central

    Ambrose, Jason H.; White, Gregory S.; Unnasch, Thomas R.; Stark, Lillian M.

    2009-01-01

    We isolated and characterized St. Louis encephalitis virus (SLEV) from cloacal swabs of naturally exposed adult sentinel chickens in 2006. Phylogenetic analysis of SLEV strains isolated in Florida indicated that Brazilian SLEV circulated in 1972 and 2006; lineages were VA and VB. PMID:19331744

  16. A hospital-based surveillance for Japanese encephalitis in Bali, Indonesia

    PubMed Central

    Kari, Komang; Liu, Wei; Gautama, Kompiang; Mammen, Mammen P; Clemens, John D; Nisalak, Ananda; Subrata, Ketut; Kim, Hyei Kyung; Xu, Zhi-Yi

    2006-01-01

    Background Japanese encephalitis (JE) is presumed to be endemic throughout Asia, yet only a few cases have been reported in tropical Asian countries such as Indonesia, Malaysia and the Philippines. To estimate the true disease burden due to JE in this region, we conducted a prospective, hospital-based surveillance with a catchment population of 599,120 children less than 12 years of age in Bali, Indonesia, from July 2001 through December 2003. Methods Balinese children presenting to any health care facility with acute viral encephalitis or aseptic meningitis were enrolled. A "confirmed" diagnosis of JE required the detection of JE virus (JEV)-specific IgM in cerebrospinal fluid, whereas a diagnosis of "probable JE" was assigned to those cases in which JEV-specific IgM was detected only in serum. Results In all, 86 confirmed and 4 probable JE cases were identified. The annualized JE incidence rate was 7.1 and adjusted to 8.2 per 100,000 for children less than 10 years of age over the 2.5 consecutive years of study. Only one JE case was found among 96,920 children 10–11 years old (0.4 per 100,000). Nine children (10%) died and 33 (37%) of the survivors had neurological sequelae at discharge. JEV was transmitted in Bali year-round with 70% of cases in the rainy season. Conclusion JE incidence and case-fatality rates in Bali were comparable to those of other JE-endemic countries of Asia. Our findings contradict the common wisdom that JE is rare in tropical Asia. Hence, the geographical range of endemic JE is broader than previously described. The results of the study support the need to introduce JE vaccination into Bali. PMID:16603053

  17. Epstein-Barr Virus Encephalitis: A Case Report

    PubMed Central

    HASHEMIAN, Somayh; ASHRAFZADEH, Farah; AKHONDIAN, Javad; BEIRAGHI TOOSI, Mehran

    2015-01-01

    Many neurologic manifestations of Epstein-Barr virus (EBV) infection have been documented, including encephalitis, aseptic meningitis, transverse myelitis, and Guillain-Barre syndrome. These manifestations can occur alone or coincidentally with the clinical picture of infectious mononucleosis. EBV encephalitis is rare and is indicated as a wide range of clinical manifestations. We report a 10-year-old girl presented with fever, gait disturbance, and bizarre behavior for one week. The results of the physical examination were unremarkable. The diagnosis of EBV encephalitis was made by changes in titers of EBV specific antibodies and MRI findings. A cranial MRI demonstrated abnormal high signal intensities in the basal ganglia and the striatal body, especially in the putamen and caudate nucleus. EBV infection should be considered when lesions are localized to the basal ganglia. PMID:25767548

  18. Recurrence of Japanese Encephalitis Epidemic in Wuhan, China, 2009–2010

    PubMed Central

    Zhu, Zerong; Tian, Junhua; Zhou, Yu; Zhang, Xiaoyong; Zheng, Xin

    2013-01-01

    Background Japanese encephalitis (JE) was once epidemic in most areas of China, including Wuhan, a city located in the central part of China. The incidence of JE dramatically decreased due to nationwide immunization with the live attenuated JE virus (JEV) vaccine, and no JE cases were reported during 2005–2008 in Wuhan. In 2009 and 2010, 31 JE cases reoccurred in this area. In this study, we investigated the causes of JE recurrence. Methods and Findings All JE cases were laboratory-confirmed by detecting the JEV-specific IgM antibody with an IgM-capture enzyme-linked immunosorbent assay (ELISA). All patients were children between 2 months and 9 years of age with a median age of 2 years. Of the 31 cases, 9 had received one or two doses of the JEV vaccine, 11 had not been immunized previously with the JEV vaccine, and 11 had an unclear immunization history. Through reverse transcription polymerase chain reaction (RT-PCR), sequencing, and phylogenetic analysis, two new strains of JEV were isolated from Culex tritaeniorhynchus and identified as genotype 1 JEV, rather than genotype 3, which circulated in this area previously. Conclusions Vaccine failure or missed vaccination may have caused JE recurrence. Local centers for disease control and prevention need to improve immunization coverage, and the efficacy of the JE vaccine needs to be reevaluated in a population at risk for disease. PMID:23326348

  19. [Japanese guidelines for the management of herpes simplex encephalitis; comparison with those from the International Management Herpes Forum].

    PubMed

    Shoji, Hiroshi

    2006-11-01

    Herpes simplex encephalitis (HSE) is still recognized as a severe sporadic encephalitis, although the mortality and morbidity rates have been decreased to 10% and 30%, respectively. This disease is diagnosed using clinical symptoms, CSF, EEG, CT, MRI, and virologic tests such as polymerase chain reaction (PCR) or enzyme immunosorbent assay (EIA). Early diagnosis and treatment are essential for HSE. However, the early symptoms of this disease are various, and the laboratory diagnostic criteria are unclear to the non-specialist. In 2005, Japanese guidelines for the management of HSE have been issued via two sets of Workshops at the Japanese Neuroinfectious Disease Congress. The diagnostic and therapeutic criteria were discussed in comparison with those from the International Management Herpes Forum (IMHF) in 2004. For a definitive diagnosis, CSF PCR for herpes simplex virus (HSV) is recommended, and the detection rate has been reported to be 60 to 80% within the 7th day of the illness. In the IMHF, the PCR method has also been the primary method for early diagnosis and for monitoring the therapy. Further, quantitative real-time PCR has become available for measuring the effectiveness of aciclovir therapy. To measure HSV antibody levels, complement antibody (CF), neutralizing antibody (NT), or enzyme-linked immunosorbent assay (ELISA or EIA) are available. Significant elevation of EIA IgG or intrathecal HSV antibody production should be shown, although these antibody responses often appear two weeks after the onset of HSE. Regarding anti-herpesvirus drugs, in both Japanese and IMHF guidelines aciclovir is consistent with the first choice, and it is recommended that its administration would be started as soon as HSE is suspected on the basis of clinical pictures, CT * MRI, EEG, or CSF findings. However, antiviral therapy may be discontinued if a negative CSF HSV PCR is obtained at > 72 hours after onset. A recent Japanese study shows the efficacy of a combination

  20. Measles virus nucleocapsid protein protects rats from encephalitis.

    PubMed Central

    Bankamp, B; Brinckmann, U G; Reich, A; Niewiesk, S; ter Meulen, V; Liebert, U G

    1991-01-01

    Lewis rats immunized with recombinant vaccinia virus expressing the nucleocapsid (N) protein of measles virus were protected from encephalitis when subsequently challenged by intracerebral infection with neurotropic measles virus. Immunized rats revealed polyvalent antibodies to the N protein of measles virus in the absence of any neutralizing antibodies as well as an N protein-specific proliferative lymphocyte response. Depletion of CD8+ T lymphocytes did not abrogate the protective potential of the N protein-specific cell-mediated immune response in rats, while protection could be adoptively transferred with N protein-specific CD4+ T lymphocytes. These results indicate that a CD4+ cell-mediated immune response specific for the N protein of measles virus is sufficient to control measles virus infections of the central nervous system. Images PMID:1825854

  1. Herpes simplex virus type 1 encephalitis in acquired immunodeficiency syndrome.

    PubMed

    Chrétien, F; Bélec, L; Hilton, D A; Flament-Saillour, M; Guillon, F; Wingertsmann, L; Baudrimont, M; de Truchis, P; Keohane, C; Vital, C; Love, S; Gray, F

    1996-10-01

    Herpes simplex (HSV) infection of the central nervous system is uncommon in AIDS and usually has an atypical topography. This review is centred around the case of a 49-year-old homosexual patient with AIDS who died from diffuse encephalopathy. Neuropathological examination revealed necrotic and haemorrhagic changes involving both temporal lobes, insulae and cingulate gyri. Cowdry type A intranuclear inclusion bodies were abundant but inflammation was minimal. Electron microscopy confirmed characteristic herpes virus particles. Immunocyto-chemistry was positive for HSV type 1 and 2. In situ hybridization and PCR, however, were positive for HSV type 1 but excluded HSV type 2. There was associated cytomegalovirus ventriculitis but clearly separated from HSV encephalitis. There were no histological features of HIV encephalitis and HIV could not be demonstrated by immunocytochemistry or by PCR to demonstrate proviral DNA. Apoptotic neurons were numerous in areas with a severe macrophage reaction. Only two pathological cases with characteristic limbic distribution and necrotic haemorrhagic histologic have been reported previously. The rarity of these reports suggests that in advanced AIDS, the immune reaction causing a typical necrotizing encephalitis cannot be mounted. Distinction between HSV type 1 and 2 infection may be difficult by immunocytochemistry and usually requires in situ hybridization, tissue culture or PCR. In AIDS patients, HSV-1 has been identified as responsible for encephalitis whereas HSV-2 has been more responsible for myelitis. Associated productive HIV infection of the CNS was found in none of the cases. In contrast, cytomegalovirus encephalitis was found in nine of 11 cases of AIDS-associated HSV encephalitis. PMID:8930949

  2. Epstein-Barr virus encephalitis with substantia nigra involvement

    PubMed Central

    Çelik, Tamer; Çelik, Ümit; Tolunay, Orkun; Kömür, Mustafa; Başpınar, Hüseyin; Yılmaz, Cengiz; Mert, Gülen; Yıldızdaş, Dinçer

    2015-01-01

    Infectious mononucleosis due to Epstein–Barr virus (EBV) is a usually benign systemic viral illness common in children. Many studies described nervous system manifestations of infectious mononucleosis with a wide spectrum of neurologic deficits. Neurologic complications of EBV are seen in both acute and reactivate infection. Herein, we describe a patient diagnosed by acute EBV encephalitis with substantia nigra involvement and excellent clinical recovery. PMID:26962357

  3. Interim Report on SNP analysis and forensic microarray probe design for South American hemorrhagic fever viruses, tick-borne encephalitis virus, henipaviruses, Old World Arenaviruses, filoviruses, Crimean-Congo hemorrhagic fever viruses, Rift Valley fever

    SciTech Connect

    Jaing, C; Gardner, S

    2012-06-05

    The goal of this project is to develop forensic genotyping assays for select agent viruses, enhancing the current capabilities for the viral bioforensics and law enforcement community. We used a multipronged approach combining bioinformatics analysis, PCR-enriched samples, microarrays and TaqMan assays to develop high resolution and cost effective genotyping methods for strain level forensic discrimination of viruses. We have leveraged substantial experience and efficiency gained through year 1 on software development, SNP discovery, TaqMan signature design and phylogenetic signature mapping to scale up the development of forensics signatures in year 2. In this report, we have summarized the whole genome wide SNP analysis and microarray probe design for forensics characterization of South American hemorrhagic fever viruses, tick-borne encephalitis viruses and henipaviruses, Old World Arenaviruses, filoviruses, Crimean-Congo hemorrhagic fever virus, Rift Valley fever virus and Japanese encephalitis virus.

  4. Persistent West Nile Virus Transmission and the Apparent Displacement St. Louis Encephalitis Virus in Southeastern California, 2003−2006

    PubMed Central

    REISEN, WILLIAM K.; LOTHROP, HUGH D.; WHEELER, SARAH S.; KENNSINGTON, MARC; GUTIERREZ, ARTURO; FANG, YING; GARCIA, SANDRA; LOTHROP, BRANKA

    2008-01-01

    West Nile virus (family Flaviviridae, genus Flavivirus, WNV) invaded the Colorado Desert biome of southern California during summer 2003 and seemed to displace previously endemic St. Louis encephalitis virus (family Flaviviridae, genus Flavivirus, SLEV, an antigenically similar Flavivirus in the Japanese encephalitis virus serocomplex). Western equine encephalomyelitis virus (family Togaviridae, genus Alphavirus, WEEV), an antigenically distinct Alphavirus, was detected during 2005 and 2006, indicating that conditions were suitable for encephalitis virus introduction and detection. Cross-protective “avian herd immunity” due to WNV infection possibly may have prevented SLEV reintroduction and/or amplification to detectable levels. During 2003−2006, WNV was consistently active at wetlands and agricultural habitats surrounding the Salton Sea where Culex tarsalis Coquillett served as the primary enzootic maintenance and amplification vector. Based on published laboratory infection studies and the current seroprevalence estimates, house sparrows, house finches, and several Ardeidae may have been important avian amplifying hosts in this region. Transmission efficiency may have been dampened by high infection rates in incompetent avian hosts, including Gamble's quail, mourning doves, common ground doves, and domestic pigeons. Early season WNV amplification and dispersal from North Shore in the southeastern portion of the Coachella Valley resulted in sporadic WNV incursions into the urbanized Upper Valley near Palm Springs, where Culex pipiens quinquefasciatus Say was the primary enzootic and bridge vector. Although relatively few human cases were detected during the 2003−2006 period, all were concentrated in the Upper Valley and were associated with high human population density and WNV infection in peridomestic populations of Cx. p. quinquefasciatus. Intensive early mosquito control during 2006 seemed to interrupt and delay transmission, perhaps setting the stage

  5. Herpes simplex virus encephalitis in Peru: a multicentre prospective study.

    PubMed

    Montano, S M; Mori, N; Nelson, C A; Ton, T G N; Celis, V; Ticona, E; Sihuincha, M; Tilley, D H; Kochel, T; Zunt, J R

    2016-06-01

    Herpes simplex virus (HSV) is one of the most commonly identified infectious aetiologies of encephalitis in North America and Europe. The epidemiology of encephalitis beyond these regions, however, is poorly defined. During 2009-2012 we enrolled 313 patients in a multicentre prospective study of encephalitis in Peru, 45 (14·4%) of whom had confirmed HSV infection. Of 38 patients with known HSV type, 84% had HSV-1 and 16% had HSV-2. Patients with HSV infection were significantly more likely to present in the summer months (44·4% vs. 20·0%, P = 0·003) and have nausea (60·0% vs. 39·8%, P = 0·01) and rash (15·6% vs. 5·3%, P = 0·01) compared to patients without HSV infection. These findings highlight differences in the epidemiology and clinical presentation of HSV encephalitis outside of the Northern Hemisphere that warrant further investigation. Furthermore, there is an urgent need for improved HSV diagnostic capacity and availability of intravenous acyclovir in Peru. PMID:26733400

  6. Epstein-Barr Virus Encephalitis in an Immunocompetent Child: A Case Report and Management of Epstein-Barr Virus Encephalitis

    PubMed Central

    Akkoc, Gulsen; Kadayifci, Eda Kepenekli; Karaaslan, Ayse; Atici, Serkan; Yakut, Nurhayat; Ocal Demir, Sevliya; Soysal, Ahmet; Bakir, Mustafa

    2016-01-01

    Epstein-Barr virus (EBV) usually causes mild, asymptomatic, and self-limited infections in children and adults; however, it may occasionally lead to severe conditions such as neurological diseases, malignant diseases, hepatic failure, and myocarditis. Epstein-Barr virus-related neurological disorders include meningitis, encephalitis, and cranial or peripheral neuritis, which are mostly seen in immunocompromised patients. The therapeutic modalities for EBV-related severe organ damage including central nervous system manifestations are still uncertain. Herein, we describe a seven-year-old boy with EBV encephalitis who presented with prolonged fever, exudative pharyngitis, reduced consciousness, and neck stiffness. Cranial magnetic resonance imaging showed contrast enhancement in the bilateral insular cortex and the right hypothalamus. The diagnosis was made by EBV-DNA amplification in both the blood and cerebrospinal fluid samples. He was discharged with acyclovir therapy without any sequelae. PMID:27213062

  7. Epstein-Barr Virus Encephalitis in an Immunocompetent Child: A Case Report and Management of Epstein-Barr Virus Encephalitis.

    PubMed

    Akkoc, Gulsen; Kadayifci, Eda Kepenekli; Karaaslan, Ayse; Atici, Serkan; Yakut, Nurhayat; Ocal Demir, Sevliya; Soysal, Ahmet; Bakir, Mustafa

    2016-01-01

    Epstein-Barr virus (EBV) usually causes mild, asymptomatic, and self-limited infections in children and adults; however, it may occasionally lead to severe conditions such as neurological diseases, malignant diseases, hepatic failure, and myocarditis. Epstein-Barr virus-related neurological disorders include meningitis, encephalitis, and cranial or peripheral neuritis, which are mostly seen in immunocompromised patients. The therapeutic modalities for EBV-related severe organ damage including central nervous system manifestations are still uncertain. Herein, we describe a seven-year-old boy with EBV encephalitis who presented with prolonged fever, exudative pharyngitis, reduced consciousness, and neck stiffness. Cranial magnetic resonance imaging showed contrast enhancement in the bilateral insular cortex and the right hypothalamus. The diagnosis was made by EBV-DNA amplification in both the blood and cerebrospinal fluid samples. He was discharged with acyclovir therapy without any sequelae. PMID:27213062

  8. A case of Japanese encephalitis in a 20 year-old Spanish sportsman, February 2013.

    PubMed

    Doti, P; Castro, P; Martínez, M J; Zboromyrska, Y; Aldasoro, E; Inciarte, A; Requena-Méndez, A; Requena, A; Milisenda, J; Fernández, S; Nicolás, J M; Muñoz, J

    2013-01-01

    We report a severe case of imported Japanese encephalitis (JE) in a healthy young Spanish traveller who developed symptoms after spending three weeks in a touristic area of Thailand. The patient was diagnosed in Thailand and subsequently transferred to Barcelona, Spain, where the Thai laboratory results were confirmed based on IgM serology. Although JE is a rare disease in travellers, this case illustrates the need for seeking travel medical advice before visiting tropical countries. PMID:24008230

  9. Immunogenicity and safety of currently available Japanese encephalitis vaccines: A systematic review

    PubMed Central

    Li, Xing; Ma, Shu-Juan; Liu, Xie; Jiang, Li-Na; Zhou, Jun-Hua; Xiong, Yi-Quan; Ding, Hong; Chen, Qing

    2015-01-01

    A number of Japanese encephalitis (JE) vaccines have been used for preventing Japanese encephalitis around the world. We here reviewed the immunogenicity and safety of the currently available Japanese encephalitis vaccines. We searched Pubmed, Embase, Web of Science, the Cochrane Library and other online databases up to March 25, 2014 for studies focusing on currently used JE vaccines in any language. The primary outcomes were the seroconversion rate against JEV and adverse events. Meta-analysis was performed for the primary outcome when available. A total of 51 articles were included. Studies were grouped on the basic types of vaccines. This systematic review led to 2 aspects of the conclusions. On one hand, all the currently available JE vaccines are safe and effective. On the other hand, the overall of JE vaccine evaluation is disorganized, the large variation in study designs, vaccine types, schedules, doses, population and few hand-to-hand trails, make direct comparisons difficult. In order to make a more evidence-based decision on optimizing the JE vaccine, it is warranted to standardize the JE vaccine evaluation research. PMID:25668666

  10. Microglia retard dengue virus-induced acute viral encephalitis

    PubMed Central

    Tsai, Tsung-Ting; Chen, Chia-Ling; Lin, Yee-Shin; Chang, Chih-Peng; Tsai, Cheng-Chieh; Cheng, Yi-Lin; Huang, Chao-Ching; Ho, Chien-Jung; Lee, Yi-Chao; Lin, Liang-Tzung; Jhan, Ming-Kai; Lin, Chiou-Feng

    2016-01-01

    Patients with dengue virus (DENV) infection may also present acute viral encephalitis through an unknown mechanism. Here, we report that encephalitic DENV-infected mice exhibited progressive hunchback posture, limbic seizures, limbic weakness, paralysis, and lethality 7 days post-infection. These symptoms were accompanied by CNS inflammation, neurotoxicity, and blood-brain barrier destruction. Microglial cells surrounding the blood vessels and injured hippocampus regions were activated by DENV infection. Pharmacologically depleting microglia unexpectedly increased viral replication, neuropathy, and mortality in DENV-infected mice. In microglia-depleted mice, the DENV infection-mediated expression of antiviral cytokines and the infiltration of CD8-positive cytotoxic T lymphocytes (CTLs) was abolished. DENV infection prompted the antigen-presenting cell-like differentiation of microglia, which in turn stimulated CTL proliferation and activation. These results suggest that microglial cells play a key role in facilitating antiviral immune responses against DENV infection and acute viral encephalitis. PMID:27279150

  11. Microglia retard dengue virus-induced acute viral encephalitis.

    PubMed

    Tsai, Tsung-Ting; Chen, Chia-Ling; Lin, Yee-Shin; Chang, Chih-Peng; Tsai, Cheng-Chieh; Cheng, Yi-Lin; Huang, Chao-Ching; Ho, Chien-Jung; Lee, Yi-Chao; Lin, Liang-Tzung; Jhan, Ming-Kai; Lin, Chiou-Feng

    2016-01-01

    Patients with dengue virus (DENV) infection may also present acute viral encephalitis through an unknown mechanism. Here, we report that encephalitic DENV-infected mice exhibited progressive hunchback posture, limbic seizures, limbic weakness, paralysis, and lethality 7 days post-infection. These symptoms were accompanied by CNS inflammation, neurotoxicity, and blood-brain barrier destruction. Microglial cells surrounding the blood vessels and injured hippocampus regions were activated by DENV infection. Pharmacologically depleting microglia unexpectedly increased viral replication, neuropathy, and mortality in DENV-infected mice. In microglia-depleted mice, the DENV infection-mediated expression of antiviral cytokines and the infiltration of CD8-positive cytotoxic T lymphocytes (CTLs) was abolished. DENV infection prompted the antigen-presenting cell-like differentiation of microglia, which in turn stimulated CTL proliferation and activation. These results suggest that microglial cells play a key role in facilitating antiviral immune responses against DENV infection and acute viral encephalitis. PMID:27279150

  12. Drought-induced amplification of Saint Louis encephalitis virus, Florida.

    PubMed

    Shaman, Jeffrey; Day, Jonathan F; Stieglitz, Marc

    2002-06-01

    We used a dynamic hydrology model to simulate water table depth (WTD) and quantify the relationship between Saint Louis encephalitis virus (SLEV) transmission and hydrologic conditions in Indian River County, Florida, from 1986 through 1991, a period with an SLEV epidemic. Virus transmission followed periods of modeled drought (specifically low WTDs 12 to 17 weeks before virus transmission, followed by a rising of the water table 1 to 2 weeks before virus transmission). Further evidence from collections of Culex nigripalpus (the major mosquito vector of SLEV in Florida) suggests that during extended spring droughts vector mosquitoes and nestling, juvenile, and adult wild birds congregate in selected refuges, facilitating epizootic amplification of SLEV. When the drought ends and habitat availability increases, the SLEV-infected Cx. nigripalpus and wild birds disperse, initiating an SLEV transmission cycle. These findings demonstrate a mechanism by which drought facilitates the amplification of SLEV and its subsequent transmission to humans. PMID:12023912

  13. Seasonal abundance & role of predominant Japanese encephalitis vectors Culex tritaeniorhynchus & Cx. gelidus Theobald in Cuddalore district, Tamil Nadu

    PubMed Central

    Ramesh, D.; Muniaraj, M.; Samuel, P. Philip; Thenmozhi, V.; Venkatesh, A.; Nagaraj, J.; Tyagi, B.K.

    2015-01-01

    Background & objectives: Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia. The first major JE outbreak occurred in 1978 and since 1981 several outbreaks had been reported in the Cuddalore district (erstwhile South Arcot), Tamil Nadu, India. Entomological monitoring was carried out during January 2010 - March 2013, to determine the seasonal abundance and transmission dynamics of the vectors of JE virus, with emphasis on the role of Culex tritaeniorhynchus and Cx. gelidus. Methods: Mosquito collections were carried out fortnightly during dusk hours in three villages viz. Soundara Solapuram, Pennadam, Erappavur of Cuddalore district. Mosquitoes were collected during dusk for a period of one hour in and around the cattle sheds using oral aspirator and torch light. The collected mosquitoes were later identified and pooled to detect JE virus (JEV) infection by enzyme linked immunosorbent assay (ELISA). Results: A total of 46,343 mosquitoes comprising of 25 species and six genera were collected. Species composition included viz, Cx. tritaeniorhynchus (46.26%), Cx. gelidus (43.12%) and other species (10.62%). A total of 17,678 specimens (403 pools) of Cx. gelidus and 14,358 specimens (309 pools) of Cx. tritaeniorhynchus were tested, of which 12 pools of Cx. gelidus and 14 pools of Cx. tritaeniorhynchus were positive for JE virus antigen. The climatic factors were negatively correlated with minimum infection rate (MIR) for both the species, except mean temperature (P<0.05) for Cx. gelidus. Interpretation & conclusions: High abundance of Cx. tritaeniorhynchus and Cx. gelidus was observed compared to other mosquito species in the study area. Detection of JEV antigen in the two species confirmed the maintenance of virus. Appropriate vector control measures need to be taken to reduce the vector abundance. PMID:26905238

  14. Rabies direct fluorescent antibody test does not inactivate rabies or eastern equine encephalitis viruses.

    PubMed

    Jarvis, Jodie A; Franke, Mary A; Davis, April D

    2016-08-01

    An examination using the routine rabies direct fluorescent antibody test was performed on rabies or Eastern equine encephalitis positive mammalian brain tissue to assess inactivation of the virus. Neither virus was inactivated with acetone fixation nor the routine test, thus laboratory employees should treat all samples as rabies and when appropriate Eastern equine encephalitis positive throughout the whole procedure. PMID:27079827

  15. Vaccine Strategies for the Control and Prevention of Japanese Encephalitis in Mainland China, 1951–2011

    PubMed Central

    Li, Minghua; Fu, Shihong; Wang, Huanyu; Lu, Zhi; Cao, Yuxi; He, Ying; Zhu, Wuyang; Zhang, Tingting; Gould, Ernest A.; Liang, Guodong

    2014-01-01

    Japanese encephalitis (JE) is arguably one of the most serious viral encephalitis diseases worldwide. China has a long history of high prevalence of Japanese encephalitis, with thousands of cases reported annually and incidence rates often exceeding 15/100,000. In global terms, the scale of outbreaks and high incidence of these pandemics has almost been unique, placing a heavy burden on the Chinese health authorities. However, the introduction of vaccines, developed in China, combined with an intensive vaccination program initiated during the 1970s, as well as other public health interventions, has dramatically decreased the incidence from 20.92/100,000 in 1971, to 0.12/100,000 in 2011. Moreover, in less readily accessible areas of China, changes to agricultural practices designed to reduce chances of mosquito bites as well as mosquito population densities have also been proven effective in reducing local JE incidence. This unprecedented public health achievement has saved many lives and provided valuable experience that could be directly applicable to the control of vector-borne diseases around the world. Here, we review and discuss strategies for promotion and expansion of vaccination programs to reduce the incidence of JE even further, for the benefit of health authorities throughout Asia and, potentially, worldwide. PMID:25121596

  16. Human immunodeficiency virus encephalitis in SCID mice.

    PubMed Central

    Persidsky, Y.; Limoges, J.; McComb, R.; Bock, P.; Baldwin, T.; Tyor, W.; Patil, A.; Nottet, H. S.; Epstein, L.; Gelbard, H.; Flanagan, E.; Reinhard, J.; Pirruccello, S. J.; Gendelman, H. E.

    1996-01-01

    The human immunodeficiency virus (HIV) is neuroinvasive and commonly causes cognitive and motor deficits during the later stages of viral infection. (referred to as HIV dementia). The mechanism(s) for disease revolves around secretory products produced from immune-activated brain macrophages/microglia. Recently, we developed an animal model system for HIV dementia that contains xenografts of HIV-1-infected cells inoculated into brains of mice with severe combined immunodeficiency (SCID). This animal system was used to quantitatively evaluate HIV-induced neuropathology. Xenografts of HIV-1-infected human monocytes (placed into the putamen and cortex of SCID mice) remained viable for 5 weeks. HIV-1 p24 antigen expression in mouse brain was persistent. Progressive inflammatory responses (including astrogliosis and cytokine production), which began at 3 days, peaked at day 12. The range of astrocyte proliferative reactions exceeded the inoculation site by > 1000 microns. Brains with virus-infected monocytes showed a > or = 1.6-fold increase in glial fibrillary acidic protein (staining distribution and intensity) as compared with similarly inoculated brains with uninfected control monocytes. These findings paralleled the accumulation and activation of murine microglia (increased branching of cell processes, formation of microglial nodules, interleukin (IL)-1 beta and IL-6 expression). An inflammatory reaction of human monocytes (as defined by HLA-DR, IL-1 beta, IL-6, and tumor necrosis factor-alpha expression) and neuronal injury (apoptosis) also developed after virus-infected monocyte xenograft placement into mouse brain tissue. These data, taken together, demonstrate that this SCID mouse model of HIV-1 neuropathogenesis can reproduce key aspects of disease (virus-infected macrophages, astrocytosis, microglial activation, and neuronal damage). This model may serve as an important means for therapeutic development directed toward improving mental function in HIV

  17. Bioluminescent detection probe for tick-borne encephalitis virus immunoassay.

    PubMed

    Burakova, Ludmila P; Kudryavtsev, Alexander N; Stepanyuk, Galina A; Baykov, Ivan K; Morozova, Vera V; Tikunova, Nina V; Dubova, Maria A; Lyapustin, Victor N; Yakimenko, Valeri V; Frank, Ludmila A

    2015-07-01

    To facilitate the detection of the tick-borne encephalitis virus (TBEV), the causative agent of one of the most severe human neuroinfections, we have developed an immunoassay based on bioluminescent hybrid protein 14D5a-Rm7 as a detection probe. The protein containing Renilla luciferase as a reporter and a single-chain variable fragment (scFv) of murine immunoglobulin to TBEV as a recognition element was constructed, produced by bacterial expression, purified, and tested. Both domains were shown to reveal their specific biological properties-affinity to the target antigen and bioluminescent activity. Hybrid protein was applied as a label for solid-phase immunoassay of the antigens, associated with the tick-borne encephalitis virus (native glycoprotein E or extracts of the infected strain of lab ticks). The assay demonstrates high sensitivity (0.056 ng of glycoprotein E; 10(4)-10(5) virus particles or 0.1 pg virions) and simplicity and is competitive with conventional methods for detection of TBEV. PMID:25925861

  18. A Preliminary Randomized Double Blind Placebo-Controlled Trial of Intravenous Immunoglobulin for Japanese Encephalitis in Nepal

    PubMed Central

    Rayamajhi, Ajit; Nightingale, Sam; Bhatta, Nisha Keshary; Singh, Rupa; Ledger, Elizabeth; Bista, Krishna Prasad; Lewthwaite, Penny; Mahaseth, Chandeshwar; Turtle, Lance; Robinson, Jaimie Sue; Galbraith, Sareen Elizabeth; Wnek, Malgorzata; Johnson, Barbara Wilmot; Faragher, Brian

    2015-01-01

    Background Japanese encephalitis (JE) virus (JEV) is a mosquito-borne flavivirus found across Asia that is closely related to West Nile virus. There is no known antiviral treatment for any flavivirus. Results from in vitro studies and animal models suggest intravenous immunoglobulin (IVIG) containing virus-specific neutralizing antibody may be effective in improving outcome in viral encephalitis. IVIG’s anti-inflammatory properties may also be beneficial. Methodology/Principal Findings We performed a pilot feasibility randomized double-blind placebo-controlled trial of IVIG containing anti-JEV neutralizing antibody (ImmunoRel, 400mg/kg/day for 5 days) in children with suspected JE at two sites in Nepal; we also examined the effect on serum neutralizing antibody titre and cytokine profiles. 22 children were recruited, 13 of whom had confirmed JE; 11 received IVIG and 11 placebo, with no protocol violations. One child (IVIG group) died during treatment and two (placebo) subsequently following hospital discharge. Overall, there was no difference in outcome between treatment groups at discharge or follow up. Passive transfer of anti-JEV antibody was seen in JEV negative children. JEV positive children treated with IVIG had JEV-specific neutralizing antibody titres approximately 16 times higher than those treated with placebo (p=0.2), which was more than could be explained by passive transfer alone. IL-4 and IL-6 were higher in the IVIG group. Conclusions/Significance A trial of IVIG for JE in Nepal is feasible. IVIG may augment the development of neutralizing antibodies in JEV positive patients. IVIG appears an appealing option for JE treatment that warrants further study. Trial Registration ClinicalTrials.gov NCT01856205 PMID:25886645

  19. A tropical menace of co-infection of Japanese encephalitis and neurocysticercosis in two children

    PubMed Central

    Yoganathan, Sangeetha; Sudhakar, Sniya Valsa; Thomas, Maya Mary; Yadav, Vikas Kapildeo

    2016-01-01

    Japanese encephalitis (JE) is a mosquito borne encephalitis caused by Flavivirus. Neurocysticercosis (NCC) is a parasitic disease of the central nervous system caused by Taenia solium. In this report, we describe the clinical profile, imaging findings, and outcome of two children with JE and coexisting NCC. Eleven and thirteen-year-old boys from the same town of Jharkhand state were brought with history of fever, seizures, altered sensorium, and extrapyramidal symptoms. Dystonia, hypomimia, bradykinesia, and dyskinesia were observed. Meige syndrome observed in one of the children is a novel finding. Magnetic resonance imaging of the brain revealed findings suggestive of JE with cysticercal granulomas. There are few reports of coexistence of JE and NCC in children. Both children were treated with ribavirin, and follow-up imaging had shown significant resolution of signal changes. Both the children had shown marked clinical improvement. Ribavirin was found to beneficial in reducing the morbidity in our patients. PMID:27606026

  20. A tropical menace of co-infection of Japanese encephalitis and neurocysticercosis in two children.

    PubMed

    Yoganathan, Sangeetha; Sudhakar, Sniya Valsa; Thomas, Maya Mary; Yadav, Vikas Kapildeo

    2016-01-01

    Japanese encephalitis (JE) is a mosquito borne encephalitis caused by Flavivirus. Neurocysticercosis (NCC) is a parasitic disease of the central nervous system caused by Taenia solium. In this report, we describe the clinical profile, imaging findings, and outcome of two children with JE and coexisting NCC. Eleven and thirteen-year-old boys from the same town of Jharkhand state were brought with history of fever, seizures, altered sensorium, and extrapyramidal symptoms. Dystonia, hypomimia, bradykinesia, and dyskinesia were observed. Meige syndrome observed in one of the children is a novel finding. Magnetic resonance imaging of the brain revealed findings suggestive of JE with cysticercal granulomas. There are few reports of coexistence of JE and NCC in children. Both children were treated with ribavirin, and follow-up imaging had shown significant resolution of signal changes. Both the children had shown marked clinical improvement. Ribavirin was found to beneficial in reducing the morbidity in our patients. PMID:27606026

  1. Field evaluation of a sentinel mosquito (Diptera: Culicidae) trap system to detect Japanese encephalitis in remote Australia.

    PubMed

    Ritchie, Scott A; Pyke, Alyssa T; Smith, Greg A; Northill, Judith A; Hall, Roy A; van den Hurk, Andrew F; Johansen, Cheryl A; Montgomery, Brian L; Mackenzie, John S

    2003-05-01

    Incursions of Japanese encephalitis (JE) virus into northern Queensland are currently monitored using sentinel pigs. However, the maintenance of these pigs is expensive, and because pigs are the major amplifying hosts of the virus, they may contribute to JE transmission. Therefore, we evaluated a mosquito-based detection system to potentially replace the sentinel pigs. Single, inactivated JE-infected Culex annulirostris Skuse and C. sitiens Wiedemann were placed into pools of uninfected mosquitoes that were housed in a MosquitoMagnet Pro (MM) trap set under wet season field conditions in Cairns, Queensland for 0, 7, or 14 d. JE viral RNA was detected (cycling threshold [CT] = 40) in 11/12, 10/14, and 2/5 pools containing 200, 1,000, and 5,000 mosquitoes, respectively, using a TaqMan real-time reverse transcription-polymerase chain reaction (RT-PCR). The ability to detect virus was not affected by the length of time pools were maintained under field conditions, although the CT score tended to increase with field exposure time. Furthermore, JE viral RNA was detected in three pools of 1,000 mosquitoes collected from Badu Island using a MM trap. These results indicated that a mosquito trap system employing self-powered traps, such as the MosquitoMagnet, and a real-time PCR system, could be used to monitor for JE in remote areas. PMID:12943100

  2. The efficacy of Japanese encephalitis vaccine in Henan, China: a case-control study.

    PubMed

    Luo, D; Yin, H; Xili, L; Song, J; Wang, Z

    1994-12-01

    A population based case-control study to evaluate Japanese encephalitis (JE) vaccine efficacy was carried out in Gusi County, Henan Province, China from June to September in 1991. This study showed that the JE vaccine had a strong protective effect. The estimate of the vaccine efficacy was 78% (95% CI = 16-94%). An unimmunized child was at 4.54 times greater risk of developing JE than were fully immunized children during the study period. The present study may have underestimated the vaccine efficacy due to evaluation based on routine vaccination which might have been affected by vaccination management and the local cold chain system. PMID:7667706

  3. Pathogenesis of simian immunodeficiency virus encephalitis: viral determinants of neurovirulence.

    PubMed Central

    Mankowski, J L; Flaherty, M T; Spelman, J P; Hauer, D A; Didier, P J; Amedee, A M; Murphey-Corb, M; Kirstein, L M; Muñoz, A; Clements, J E; Zink, M C

    1997-01-01

    To examine the relationship between macrophage tropism and neurovirulence, macaques were inoculated with two recombinant hybrid viruses derived from the parent viruses SIVmac239, a lymphocyte-tropic, non-neurovirulent clone, and SIV/17E-Br, a macrophage-tropic, neurovirulent virus strain. The first recombinant, SIV/17E-Cl, contained the portion of the env gene that encodes the surface glycoprotein and a short segment of the transmembrane glycoprotein of SIV/17E-Br in the backbone of SIVmac239. Unlike SIVmac239, SIV/17E-Cl replicated productively in macrophages, demonstrating that sequences in the surface portion of env determine macrophage tropism. None of five macaques inoculated with SIV/17E-Cl developed simian immunodeficiency virus (SIV) encephalitis. The second recombinant, SIV/17E-Fr, which contained the entire env and nef genes and the 3' long terminal repeat of SIV/17E-Br in the SIVmac239 backbone, was also macrophage tropic. Six of nine macaques inoculated with SIV/17E-Fr developed SIV encephalitis ranging from mild to moderate in severity, indicating a significant (P = 0.031) difference in the neurovirulence of the two recombinants. In both groups of macaques, CD4+ cell counts declined gradually during infection and there was no significant difference in the rate of the decline between the two groups of macaques. This study demonstrated that macrophage tropism alone is not sufficient for the development of neurological disease. In addition, it showed that while sequences in the surface portion of the envelope gene determine macrophage tropism, additional sequences derived from the transmembrane portion of envelope and/or nef confer neurovirulence. PMID:9223498

  4. Seroprevalence of Cysticercus Antibodies in Japanese Encephalitis Patients in Upper Assam, India: A Hospital Based Study

    PubMed Central

    Mazumdar, Himangshu; Saikia, Lahari

    2016-01-01

    Introduction Co-infection of Japanese Encephalitis (JE) and Cysticercosis is attributed mainly to the common epidemiological features between the two diseases. Not much is known about the clinical implications of one infection over the other. Aim The study aimed at establishing whether JE-Cysticercosis co-infection is prevalent in the Upper Assam districts and to explore additional details about such co-infections both clinically and epidemiologically. Materials and Methods The present study was a retrospective cross-sectional hospital based study conducted between July 2013 and June 2014 and included 272 Acute Encephalitis Syndrome (AES) patients. Out of this, 137 JE positive and 135 non-JE Acute encephalitis patients were taken as cases and controls respectively. The diagnosis of JE and Cysticercosis was established by ELISA. Statistical Analysis EpiInfo ver. 7 was used for statistical analysis. Chi-square was used and p-value < 0.05 was considered to be statistically significant. Results The association of Cysticercosis with JE was found to be statistically significant (14.6%, p = 0.0019) in the cases with reference to the controls (3.7%). Moreover, the co-infections were found to be more common in case of adults (19.32%, p = 0.0360); with males having a greater odds (5.25, p = 0.0008) of harbouring the parasite as compared to females. Conclusion The study proves that the association of Cysticercosis and JE holds true in this region. PMID:27437215

  5. Japanese encephalitis vaccines: current vaccines and future prospects.

    PubMed

    Monath, T P

    2002-01-01

    Vaccination against JE ideally should be practiced in all areas of Asia where the virus is responsible for human disease. The WHO has placed a high priority on the development of a new vaccine for prevention of JE. Some countries in Asia (Japan, South Korea, North Korea, Taiwan, Vietnam, Thailand, and the PRC) manufacture JE vaccines and practice childhood immunization, while other countries suffering endemic or epidemic disease (India, Nepal, Laos, Cambodia, Bangladesh, Myanmar, Malaysia, Indonesia and the Philippines) have no JE vaccine manufacturing or policy for use. With the exception of the PRC, all countries practicing JE vaccination use formalin inactivated mouse brain vaccines, which are relatively expensive and are associated with rare but clinically significant allergic and neurological adverse events. New inactivated JE vaccines manufactured in Vero cells are in advanced preclinical or early clinical development in Japan, South Korea, Taiwan, and the PRC. An empirically derived, live attenuated vaccine (SA14-14-2) is widely used in the PRC. Trials in the PRC have shown SA14-14-2 to be safe and effective when administered in a two-dose regimen, but regulatory concerns over manufacturing and control have restricted international distribution. The genetic basis of attenuation of SA14-14-2 has been partially defined. A new live attenuated vaccine (ChimeriVax-JE) that uses a reliable flavivirus vaccine--yellow fever 17D--as a live vector for the envelope genes of SA14-14-2 virus is in early clinical trials and appears to be well tolerated and immunogenic after a single dose. Vaccinia and avipox vectored vaccines have also been tested clinically, but are no longer being pursued due to restricted effectiveness mediated by anti-vector immunity. Other approaches to JE vaccines--including naked DNA, oral vaccination, and recombinant subunit vaccines--have been reviewed. PMID:12082985

  6. Sensitivity of the VecTest antigen assay for eastern equine encephalitis and western equine encephalitis viruses.

    PubMed

    Nasci, Roger S; Gottfried, Kristy L; Burkhalter, Kristen L; Ryan, Jeffrey R; Emmerich, Eva; Davé, Kirti

    2003-12-01

    VecTest assays for detecting eastern equine encephalitis virus (EEE) and western equine encephalitis virus (WEE) antigen in mosquito pools were evaluated to determine their sensitivity and specificity by using a range of EEE, WEE, St. Louis encephalitis virus (SLE), and West Nile virus (WN) dilutions as well as individual and pooled mosquitoes containing EEE or WEE. The EEE test produced reliable positive results with samples containing > or = 5.3 log10 plaque-forming units (PFU) of EEE/ml, and the WEE test produced reliable positive results with samples containing > or = 4.7 log10 PFU WEE/ml. Both assays detected the respective viral antigens in single virus-positive mosquitoes and in pools containing a single positive mosquito and 49 negative specimens. The SLE and WN assays also contained on the dipsticks accurately detected their respective viruses. No evidence was found of cross reaction or false positives in any of the tests. The VecTest assays were less sensitive than the EEE- and WEE-specific TaqMan reverse transcriptase polymerase chain reaction and Vero cell plaque assay, but appear to be useful for detecting arboviruses in mosquito-based arbovirus surveillance programs. PMID:14710752

  7. Change in Dengue and Japanese Encephalitis Seroprevalence Rates in Sri Lanka

    PubMed Central

    Jeewandara, Chandima; Gomes, Laksiri; Paranavitane, S. A.; Tantirimudalige, Mihiri; Panapitiya, Sumedha Sandaruwan; Jayewardene, Amitha; Fernando, Samitha; Fernando, R. H.; Prathapan, Shamini

    2015-01-01

    Background Sri Lanka has been affected by epidemics of dengue infections for many decades and the incidence and severity of dengue infections have been rising each year. Therefore, we investigated the age stratified seroprevalence of dengue infections in order to facilitate future dengue vaccine strategies. In addition, since the symptomatic dengue infections have increased during the past few decades, we also investigated the possible association with Japanese Encephalitis Virus (JEV) antibody seropositivity with symptomatic dengue in a community cohort in Sri Lanka. Methods 1689 healthy individuals who were attending a primary health care facility were recruited. Dengue and JEV antibody status was determined in all individuals and JEV vaccination status was recorded. Results 1152/1689 (68.2%) individuals were seropositive for dengue and only 133/1152 (11.5%) of them had been hospitalized to due to dengue. A significant and positive correlation was observed for dengue antibody seropositivity and age in children (Spearmans R = 0.84, p = 0.002) and in adults (Spearmans R = 0.96, p = 0.004). We observed a significant rise in the age stratified seroprevalence rates in children over a period of 12 years. For instance, in year 2003 the annual seroconversion rate was 1.5% per annum, which had risen to 3.79% per annum by 2014. We also found that both adults (p<0.001) and in children (p = 0.03) who were hospitalized due to dengue were more likely to be seropositive for JEV antibodies. However, 244 (91.4%) of adults who were seropositive for JEV had not had the JEV vaccine. Conclusions Dengue seroprevalence rates have risen significantly over the last 12 years in Sri Lanka, possibly due to increased transmission. As individuals who were hospitalized due to dengue were more likely to be seropositive for JEV, the possibility of cross-reactive assays and/or of JEV infection on immunity to the DENV and clinical disease severity should be further investigated. PMID:26696417

  8. Human-like antibodies neutralizing Western equine encephalitis virus

    PubMed Central

    Hülseweh, Birgit; Rülker, Torsten; Pelat, Thibaut; Langermann, Claudia; Frenzel, Andrè; Schirrmann, Thomas; Dübel, Stefan; Thullier, Philippe; Hust, Michael

    2014-01-01

    This study describes the development of the first neutralizing antibodies against Western equine encephalitis virus (WEEV), a member of the genus Alphavirus. WEEV is transmitted by mosquitoes and can spread to the human central nervous system, causing symptoms ranging from mild febrile reactions to life-threatening encephalitis. WEEV has been classified as a biological warfare agent by the US Centers for Disease Control and Prevention. No anti-WEEV drugs are currently commercially available. Neutralizing antibodies are useful for the pre- and post-exposure treatment of WEEV infections. In this study, two immune antibody gene libraries were constructed from two macaques immunized with inactivated WEEV. Four antibodies were selected from these libraries and recloned as scFv-Fc, with a human Fc part. These antibodies bound WEEV specifically in ELISA with little or no cross-reaction with other alphaviruses. They were further analyzed by immunohistochemistry. All binders were suitable for the intracellular detection of WEEV particles. Neutralizing activity was determined in vitro. Three of the four antibodies were found to be neutralizing; about 1 ng/mL of the best antibody (ToR69–3A2) neutralized 50% of 5x104 TCID50/mL. Due to its human-like nature with a germinality index of 89% (VH) and 91% (VL), the ToR69–3A2 antibody is a promising candidate for future passive vaccine development. PMID:24518197

  9. West Nile Virus Encephalitis in a Patient with Neuroendocrine Carcinoma

    PubMed Central

    2016-01-01

    Importance. Oftentimes, when patients with metastatic cancer present with acute encephalopathy, it is suspected to be secondary to their underlying malignancy. However, there are multiple causes of delirium such as central nervous system (CNS) infections, electrolyte abnormalities, and drug adverse reactions. Because West Nile Virus (WNV) neuroinvasive disease has a high mortality rate in immunosuppressed patients, a high index of suspicion is required in patients who present with fever, altered mental status, and other neurological symptoms. Observations. Our case report details a single patient with brain metastases who presented with unexplained fever, encephalopathy, and new-onset tremors. Initially, it was assumed that his symptoms were due to his underlying malignancy or seizures. However, because his unexplained fevers persisted, lumbar puncture was pursued. Cerebrospinal fluid analysis included WNV polymerase chain reaction and serologies were ordered which eventually led to diagnosis of WNV encephalitis. Conclusions and Relevance. Patients with metastatic cancer who present with encephalopathy are often evaluated with assumption that malignancy is the underlying etiology. This can lead to delays in diagnosis and possible mistreatment. Our case highlights the importance of maintaining a broad differential diagnosis and an important diagnostic consideration of WNV encephalitis in patients with cancer. PMID:27516915

  10. Cerebrospinal Fluid Biomarkers of Simian Immunodeficiency Virus Encephalitis : CSF Biomarkers of SIV Encephalitis.

    PubMed

    Bissel, Stephanie J; Kofler, Julia; Nyaundi, Julia; Murphey-Corb, Michael; Wisniewski, Stephen R; Wiley, Clayton A

    2016-06-01

    Antiretroviral therapy has led to increased survival of HIV-infected patients but also increased prevalence of HIV-associated neurocognitive disorders. We previously identified YKL40 as a potential cerebrospinal fluid (CSF) biomarker of lentiviral central nervous system (CNS) disease in HIV-infected patients and in the macaque model of HIV encephalitis. The aim of this study was to define the specificity and sensitivity along with the predictive value of YKL40 as a biomarker of encephalitis and to assess its relationship to CSF viral load. CSF YKL40 and SIV RNA concentrations were analyzed over the course of infection in 19 SIV-infected pigtailed macaques and statistical analyses were performed to evaluate the relationship to encephalitis. Using these relationships, CSF alterations of 31 neuroimmune markers were studied pre-infection, during acute and asymptomatic infection, at the onset of encephalitis, and at necropsy. YKL40 CSF concentrations above 1122 ng/ml were found to be a specific and sensitive biomarker for the presence of encephalitis and were highly correlated with CSF viral load. Macaques that developed encephalitis had evidence of chronic CNS immune activation during early, asymptomatic, and end stages of infection. At the onset of encephalitis, CSF demonstrated a rise of neuroimmune markers associated with macrophage recruitment, activation and interferon response. CSF YKL40 concentration and viral load are valuable biomarkers to define the onset of encephalitis. Chronic CNS immune activation precedes the development of encephalitis while some responses suggest protection from CNS lentiviral disease. PMID:27059917

  11. Development of a serodiagnostic multi-species ELISA against tick-borne encephalitis virus using subviral particles.

    PubMed

    Inagaki, Eri; Sakai, Mizuki; Hirano, Minato; Muto, Memi; Kobayashi, Shintaro; Kariwa, Hiroaki; Yoshii, Kentaro

    2016-07-01

    Tick-borne encephalitis virus (TBEV) is a zoonotic agent causing severe encephalitis in humans. A wide range of animal species could be infected with TBEV in endemic areas. A serological survey of wild animals is effective in identifying TBEV-endemic areas. Safe, simple, and reliable TBEV serodiagnostic tools are needed to test animals. In this study, ELISA was developed to detect anti-TBEV specific antibodies in multi-species of animals, using recombinant subviral particles (SPs) with an affinity tag and protein A/G. A Strep-tag was fused at the N terminus of the E protein of the plasmid coding TBEV prME. The E proteins with Strep-tag were secreted as SPs, of which Strep-tag was exposed on the surface. The tagged E proteins were associated with prM. The SPs with Strep-tag were applied as the antigen of ELISA, and TBEV-specific antibodies were detected by the protein A/G. Compared to neutralization test results, the ELISA showed 96.8% sensitivity and 97.7% specificity in rodents and 95.1% sensitivity and 96.0% specificity in humans, without cross-reactivity with antibodies to Japanese encephalitis virus. These results indicate that our ELISA would be useful to detect TBE-specific antibodies in a wide range of animal species. PMID:26969490

  12. Alexander the Great and West Nile Virus Encephalitis

    PubMed Central

    Marr, John S.

    2003-01-01

    Alexander the Great died in Babylon in 323 BC. His death at age 32 followed a 2-week febrile illness. Speculated causes of death have included poisoning, assassination, and a number of infectious diseases. One incident, mentioned by Plutarch but not considered by previous investigators, may shed light on the cause of Alexander’s death. The incident, which occurred as he entered Babylon, involved a flock of ravens exhibiting unusual behavior and subsequently dying at his feet. The inexplicable behavior of ravens is reminiscent of avian illness and death weeks before the first human cases of West Nile virus infection were identified in the United States. We posit that Alexander may have died of West Nile encephalitis. PMID:14725285

  13. Trend of Japanese encephalitis in Uttar Pradesh, India from 2011 to 2013.

    PubMed

    Jain, P; Singh, A K; Khan, D N; Pandey, M; Kumar, R; Garg, R; Jain, A

    2016-01-01

    As indicated by the sporadic Japanese encephalitis (JE) cases reported from the districts of Uttar Pradesh (UP), India, the disease is endemic in the state despite the fact that a JE vaccination programme has been ongoing in the state since 2006. Hence, the present study was undertaken to study the annual trend of JE in UP during January 2011 to December 2013. CSF and/or serum samples collected from acute encephalitis syndrome (AES) cases were referred to the virology laboratory at King George's Medical University, Lucknow and were tested for anti-JEV IgM antibodies by JEV MAC-ELISA kit. The study reveals that 26·9%, 9·9% and 14·8% of AES cases were positive for anti-JEV IgM in the years 2011, 2012 and 2013, respectively. Of the total JE confirmed cases, 30% were adults. Males were more commonly affected than females. A distinct peak of JE was seen in the monsoon and post-monsoon season, although sporadic cases were also reported in other months. JE vaccination by district in UP is discussed. This study reports that the proportion of JE positives in AES cases is decreasing in UP although the number of AES cases has not decreased. The study also discusses the probable causes of this decrease, including JE vaccination and natural periodicity due to herd immunity. PMID:26112391

  14. Venezuelan Equine Encephalitis Virus Infection of Spiny Rats

    PubMed Central

    Carrara, Anne-Sophie; Gonzales, Marta; Ferro, Cristina; Tamayo, Margarita; Aronson, Judith; Paessler, Slobodan; Anishchenko, Michael; Boshell, Jorge

    2005-01-01

    Enzootic strains of Venezuelan equine encephalitis virus (VEEV) circulate in forested habitats of Mexico, Central, and South America, and spiny rats (Proechimys spp.) are believed to be the principal reservoir hosts in several foci. To better understand the host-pathogen interactions and resistance to disease characteristic of many reservoir hosts, we performed experimental infections of F1 progeny from Proechimys chrysaeolus collected at a Colombian enzootic VEEV focus using sympatric and allopatric virus strains. All animals became viremic with a mean peak titer of 3.3 log10 PFU/mL, and all seroconverted with antibody titers from 1:20 to 1:640, which persisted up to 15 months. No signs of disease were observed, including after intracerebral injections. The lack of detectable disease and limited histopathologic lesions in these animals contrast dramatically with the severe disease and histopathologic findings observed in other laboratory rodents and humans, and support their role as reservoir hosts with a long-term coevolutionary relationship to VEEV. PMID:15890116

  15. Use of Japanese Encephalitis Vaccine in US Travel Medicine Practices in Global TravEpiNet

    PubMed Central

    Deshpande, Bhushan R.; Rao, Sowmya R.; Jentes, Emily S.; Hills, Susan L.; Fischer, Marc; Gershman, Mark D.; Brunette, Gary W.; Ryan, Edward T.; LaRocque, Regina C.

    2014-01-01

    Few data regarding the use of Japanese encephalitis (JE) vaccine in clinical practice are available. We identified 711 travelers at higher risk and 7,578 travelers at lower risk for JE who were seen at US Global TravEpiNet sites from September of 2009 to August of 2012. Higher-risk travelers were younger than lower-risk travelers (median age = 29 years versus 40 years, P < 0.001). Over 70% of higher-risk travelers neither received JE vaccine during the clinic visit nor had been previously vaccinated. In the majority of these instances, clinicians determined that the JE vaccine was not indicated for the higher-risk traveler, which contradicts current recommendations of the Advisory Committee on Immunization Practices. Better understanding is needed of the clinical decision-making regarding JE vaccine in US travel medicine practices. PMID:25070999

  16. Japanese Encephalitis in Travelers from Non-Endemic Countries, 1973–2008

    PubMed Central

    Hills, Susan L.; Griggs, Anne C.; Fischer, Marc

    2010-01-01

    Japanese encephalitis (JE) is a severe disease and a risk for travelers who visit JE-endemic countries. We reviewed all published JE cases in travelers from non-endemic areas from 1973 through 2008, and assessed factors related to risk of infection. There were 55 cases that occurred in citizens of 17 countries. Age range of case-patients was 1–91 years (median = 34 years). Ten (18%) persons died and 24 (44%) had mild to severe sequelae. In a detailed risk assessment of 37 case-patients, 24 (65%) had spent ≥ 1 month in JE-endemic areas, and most had factors identified that may have increased infection risk. The estimate of overall JE risk was low, < 1 case/1 million travelers to JE-endemic countries. Nonetheless, for each traveler, a careful assessment of itinerary and activities, a decision on vaccination, and information on mosquito precautions are needed to reduce the risk of this disease. PMID:20439978

  17. Characterization of a Siberian Virus Isolated from a Patient with Progressive Chronic Tick-Borne Encephalitis

    PubMed Central

    Gritsun, T. S.; Frolova, T. V.; Zhankov, A. I.; Armesto, M.; Turner, S. L.; Frolova, M. P.; Pogodina, V. V.; Lashkevich, V. A.; Gould, E. A.

    2003-01-01

    A strain of Tick-borne encephalitis virus designated Zausaev (Za) was isolated in Siberia from a patient who died of a progressive (2-year) form of tick-borne encephalitis 10 years after being bitten by a tick. The complete genomic sequence of this virus was determined, and an attempt was made to correlate the sequence with the biological characteristics of the virus. Phylogenetic analysis demonstrated that this virus belongs to the Siberian subtype of Tick-borne encephalitis virus. Comparison of Za virus with two related viruses, a Far Eastern isolate, Sofjin, and a Siberian isolate, Vasilchenko, revealed differences among the three viruses in pathogenicity for Syrian hamsters, cytopathogenicity for PS cells, plaque morphology, and the electrophoretic profiles of virus-specific nonstructural proteins. Comparative amino acid alignments revealed 10 individual amino acid substitutions in the Za virus polyprotein sequence that were different from those of other tick-borne flaviviruses. Notably, the dimeric form of the Za virus NS1 protein migrated in polyacrylamide gels as a heterogeneous group of molecules with a significantly higher electrophoretic mobility than those of the Sofjin and Vasilchenko viruses. Two amino acid substitutions, T277→V and E279→G, within the NS1 dimerization domain are probably responsible for the altered oligomerization of Za virus NS1. These studies suggest that the patient from whom Za virus was isolated died due to increased pathogenicity of the latent virus following spontaneous mutagenesis. PMID:12477807

  18. Silent Circulation of St. Louis Encephalitis Virus Prior to an Encephalitis Outbreak in Cordoba, Argentina (2005)

    PubMed Central

    Díaz, Luis Adrian; Albrieu Llinás, Guillermo; Vázquez, Ana; Tenorio, Antonio; Contigiani, Marta Silvia

    2012-01-01

    St. Louis encephalitis virus is a complex zoonoses. In 2005, 47 laboratory-confirmed and probable clinical cases of SLEV infection were reported in Córdoba, Argentina. Although the causes of 2005 outbreak remain unknown, they might be related not only to virological factors, but also to ecological and environmental conditions. We hypothesized that one of the factors for SLE reemergence in Córdoba, Argentina, was the introduction of a new SLEV genotype (SLEV genotype III), with no previous activity in the area. In order to evaluate this hypothesis we carried out a molecular characterization of SLEV detections from mosquitoes collected between 2001 and 2004 in Córdoba city. A total of 315 mosquito pools (11,002 individuals) including 12 mosquitoes species were analyzed. Overall, 20 pools (8 mosquitoes species) were positive for SLEV. During this study, genotypes II, V and VII were detected. No mosquito pool infected with genotype III was detected before the 2005 outbreak. Genotype V was found every year and in the 8 sampled sites. Genotypes II and VII showed limited temporal and spatial activities. We cannot dismiss the association of genotype II and V as etiological agents during the outbreak. However, the silent circulation of other SLEV strains in Córdoba city before the 2005 outbreak suggests that the introduction of genotype III was an important factor associated to this event. Not mutually exclusive, other factors such as changes in avian hosts and mosquitoes vectors communities, driven by climatic and environmental modifications, should also be taken into consideration in further studies. PMID:22303490

  19. The role of IKKβ in Venezuelan equine encephalitis virus infection.

    PubMed

    Amaya, Moushimi; Voss, Kelsey; Sampey, Gavin; Senina, Svetlana; de la Fuente, Cynthia; Mueller, Claudius; Calvert, Valerie; Kehn-Hall, Kylene; Carpenter, Calvin; Kashanchi, Fatah; Bailey, Charles; Mogelsvang, Soren; Petricoin, Emanuel; Narayanan, Aarthi

    2014-01-01

    Venezuelan equine encephalitis virus (VEEV) belongs to the genus Alphavirus, family Togaviridae. VEEV infection is characterized by extensive inflammation and studies from other laboratories implicated an involvement of the NF-κB cascade in the in vivo pathology. Initial studies indicated that at early time points of VEEV infection, the NF-κB complex was activated in cells infected with the TC-83 strain of VEEV. One upstream kinase that contributes to the phosphorylation of p65 is the IKKβ component of the IKK complex. Our previous studies with Rift valley fever virus, which exhibited early activation of the NF-κB cascade in infected cells, had indicated that the IKKβ component underwent macromolecular reorganization to form a novel low molecular weight form unique to infected cells. This prompted us to investigate if the IKK complex undergoes a comparable macromolecular reorganization in VEEV infection. Size-fractionated VEEV infected cell extracts indicated a macromolecular reorganization of IKKβ in VEEV infected cells that resulted in formation of lower molecular weight complexes. Well-documented inhibitors of IKKβ function, BAY-11-7082, BAY-11-7085 and IKK2 compound IV, were employed to determine whether IKKβ function was required for the production of infectious progeny virus. A decrease in infectious viral particles and viral RNA copies was observed with inhibitor treatment in the attenuated and virulent strains of VEEV infection. In order to further validate the requirement of IKKβ for VEEV replication, we over-expressed IKKβ in cells and observed an increase in viral titers. In contrast, studies carried out using IKKβ(-/-) cells demonstrated a decrease in VEEV replication. In vivo studies demonstrated that inhibitor treatment of TC-83 infected mice increased their survival. Finally, proteomics studies have revealed that IKKβ may interact with the viral protein nsP3. In conclusion, our studies have revealed that the host IKKβ protein may be

  20. The Role of IKKβ in Venezuelan Equine Encephalitis Virus Infection

    PubMed Central

    Amaya, Moushimi; Voss, Kelsey; Sampey, Gavin; Senina, Svetlana; de la Fuente, Cynthia; Mueller, Claudius; Calvert, Valerie; Kehn-Hall, Kylene; Carpenter, Calvin; Kashanchi, Fatah; Bailey, Charles; Mogelsvang, Soren; Petricoin, Emanuel; Narayanan, Aarthi

    2014-01-01

    Venezuelan equine encephalitis virus (VEEV) belongs to the genus Alphavirus, family Togaviridae. VEEV infection is characterized by extensive inflammation and studies from other laboratories implicated an involvement of the NF-κB cascade in the in vivo pathology. Initial studies indicated that at early time points of VEEV infection, the NF-κB complex was activated in cells infected with the TC-83 strain of VEEV. One upstream kinase that contributes to the phosphorylation of p65 is the IKKβ component of the IKK complex. Our previous studies with Rift valley fever virus, which exhibited early activation of the NF-κB cascade in infected cells, had indicated that the IKKβ component underwent macromolecular reorganization to form a novel low molecular weight form unique to infected cells. This prompted us to investigate if the IKK complex undergoes a comparable macromolecular reorganization in VEEV infection. Size-fractionated VEEV infected cell extracts indicated a macromolecular reorganization of IKKβ in VEEV infected cells that resulted in formation of lower molecular weight complexes. Well-documented inhibitors of IKKβ function, BAY-11-7082, BAY-11-7085 and IKK2 compound IV, were employed to determine whether IKKβ function was required for the production of infectious progeny virus. A decrease in infectious viral particles and viral RNA copies was observed with inhibitor treatment in the attenuated and virulent strains of VEEV infection. In order to further validate the requirement of IKKβ for VEEV replication, we over-expressed IKKβ in cells and observed an increase in viral titers. In contrast, studies carried out using IKKβ−/− cells demonstrated a decrease in VEEV replication. In vivo studies demonstrated that inhibitor treatment of TC-83 infected mice increased their survival. Finally, proteomics studies have revealed that IKKβ may interact with the viral protein nsP3. In conclusion, our studies have revealed that the host IKKβ protein may be

  1. Provenance and Geographic Spread of St. Louis Encephalitis Virus

    PubMed Central

    Kopp, Anne; Gillespie, Thomas R.; Hobelsberger, Daniel; Estrada, Alejandro; Harper, James M.; Miller, Richard A.; Eckerle, Isabella; Müller, Marcel A.; Podsiadlowski, Lars; Leendertz, Fabian H.; Drosten, Christian; Junglen, Sandra

    2013-01-01

    ABSTRACT St. Louis encephalitis virus (SLEV) is the prototypic mosquito-borne flavivirus in the Americas. Birds are its primary vertebrate hosts, but amplification in certain mammals has also been suggested. The place and time of SLEV emergence remain unknown. In an ecological investigation in a tropical rainforest in Palenque National Park, Mexico, we discovered an ancestral variant of SLEV in Culex nigripalpus mosquitoes. Those SLEV-Palenque strains form a highly distinct phylogenetic clade within the SLEV species. Cell culture studies of SLEV-Palenque versus epidemic SLEV (MSI-7) revealed no growth differences in insect cells but a clear inability of SLEV-Palenque to replicate in cells from birds, cotton rats, and free-tailed bats permissive for MSI-7 replication. Only cells from nonhuman primates and neotropical fruit bats were moderately permissive. Phylogeographic reconstruction identified the common ancestor of all epidemic SLEV strains to have existed in an area between southern Mexico and Panama ca. 330 years ago. Expansion of the epidemic lineage occurred in two waves, the first representing emergence near the area of origin and the second involving almost parallel appearances of the virus in the lower Mississippi and Amazon delta regions. Early diversification events overlapped human habitat invasion during the post-Columbian era. Several documented SLEV outbreaks, such as the 1964 Houston epidemic or the 1990 Tampa epidemic, were predated by the arrival of novel strains between 1 and 4 years before the outbreaks. Collectively, our data provide insight into the putative origins of SLEV, suggesting that virus emergence was driven by human invasion of primary rainforests. PMID:23760463

  2. First human case of tick-borne encephalitis virus infection acquired in the Netherlands, July 2016.

    PubMed

    de Graaf, Joris A; Reimerink, Johan H J; Voorn, G Paul; Bij de Vaate, Elisabeth A; de Vries, Ankje; Rockx, Barry; Schuitemaker, Alie; Hira, Vishal

    2016-08-18

    In July 2016, the first autochthonous case of tick-borne encephalitis was diagnosed in the Netherlands, five days after a report that tick-borne encephalitis virus (TBEV) had been found in Dutch ticks. A person in their 60s without recent travel history suffered from neurological symptoms after a tick bite. TBEV serology was positive and the tick was positive in TBEV qRT-PCR. TBEV infection should be considered in patients with compatible symptoms in the Netherlands. PMID:27562931

  3. Varicella-zoster virus associated encephalitis in a patient undergoing haemodialysis

    PubMed Central

    Al-Mula Abed, Yasser W.

    2015-01-01

    We describe an elderly gentleman with end stage renal disease on haemodialysis who presented with ophthalmic zoster infection and was discharged on oral acyclovir. He presented again a few days later with confusion and expressive dysphasia. Differential diagnosis was mainly between varicella-zoster virus (VZV) associated encephalitis versus acyclovir toxicity. Cerebrospinal fluid analysis confirmed the diagnosis of VZV associated encephalitis and the patient was treated with intravenous acyclovir and steroids with full recovery back to pre-admission neurological status. PMID:26865994

  4. Characterization of Genetic Variability of Venezuelan Equine Encephalitis Viruses

    PubMed Central

    Gardner, Shea N.; McLoughlin, Kevin; Be, Nicholas A.; Allen, Jonathan; Weaver, Scott C.; Forrester, Naomi; Guerbois, Mathilde; Jaing, Crystal

    2016-01-01

    Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne alphavirus that has caused large outbreaks of severe illness in both horses and humans. New approaches are needed to rapidly infer the origin of a newly discovered VEEV strain, estimate its equine amplification and resultant epidemic potential, and predict human virulence phenotype. We performed whole genome single nucleotide polymorphism (SNP) analysis of all available VEE antigenic complex genomes, verified that a SNP-based phylogeny accurately captured the features of a phylogenetic tree based on multiple sequence alignment, and developed a high resolution genome-wide SNP microarray. We used the microarray to analyze a broad panel of VEEV isolates, found excellent concordance between array- and sequence-based SNP calls, genotyped unsequenced isolates, and placed them on a phylogeny with sequenced genomes. The microarray successfully genotyped VEEV directly from tissue samples of an infected mouse, bypassing the need for viral isolation, culture and genomic sequencing. Finally, we identified genomic variants associated with serotypes and host species, revealing a complex relationship between genotype and phenotype. PMID:27054586

  5. Characterization of Genetic Variability of Venezuelan Equine Encephalitis Viruses.

    PubMed

    Gardner, Shea N; McLoughlin, Kevin; Be, Nicholas A; Allen, Jonathan; Weaver, Scott C; Forrester, Naomi; Guerbois, Mathilde; Jaing, Crystal

    2016-01-01

    Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne alphavirus that has caused large outbreaks of severe illness in both horses and humans. New approaches are needed to rapidly infer the origin of a newly discovered VEEV strain, estimate its equine amplification and resultant epidemic potential, and predict human virulence phenotype. We performed whole genome single nucleotide polymorphism (SNP) analysis of all available VEE antigenic complex genomes, verified that a SNP-based phylogeny accurately captured the features of a phylogenetic tree based on multiple sequence alignment, and developed a high resolution genome-wide SNP microarray. We used the microarray to analyze a broad panel of VEEV isolates, found excellent concordance between array- and sequence-based SNP calls, genotyped unsequenced isolates, and placed them on a phylogeny with sequenced genomes. The microarray successfully genotyped VEEV directly from tissue samples of an infected mouse, bypassing the need for viral isolation, culture and genomic sequencing. Finally, we identified genomic variants associated with serotypes and host species, revealing a complex relationship between genotype and phenotype. PMID:27054586

  6. Isolation of caprine arthritis encephalitis virus from goats in Mexico.

    PubMed Central

    Daltabuit Test, M; de la Concha-Bermejillo, A; Espinosa, L E; Loza Rubio, E; Aguilar Setién, A

    1999-01-01

    A lentivirus was isolated from 2 goats in Mexico that were seropositive to caprine arthritis encephalitis virus (CAEV) by the agar gel immunodiffusion (AGID) test. The lentivirus was identified as CAEV by the observation of giant multinucleated cells (syncytia) in goat synovial membrane (GSM) monolayers co-cultivated with blood mononuclear (BMN) cells from the seropositive goats, and by amplifying a DNA segment of the CAEV gag gene using the polymerase chain reaction (PCR) technique. Subsequently, cell supernatants from the GSM cells co-cultivated with BMN cells were used to infect 2 CAEV-seronegative goats. These goats seroconverted to CAEV as determined by the AGID test, and CAEV was re-isolated from these goats. One of the goats developed polyarthritis 8 mo after inoculation. Previous serological surveys indicate that infection with CAEV is prevalent among goats in Mexico. To our knowledge this is the first report of CAEV isolation in Mexico. Because of globalization of markets and increased trading among nations, the rapid identification and reporting of diseases such as CAEV are important to prevent the dissemination of these diseases. Images Figure 1. Figure 2. PMID:10480464

  7. Characterization of genetic variability of Venezuelan equine encephalitis viruses

    DOE PAGESBeta

    Gardner, Shea N.; McLoughlin, Kevin; Be, Nicholas A.; Allen, Jonathan; Weaver, Scott C.; Forrester, Naomi; Guerbois, Mathilde; Jaing, Crystal

    2016-04-07

    Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne alphavirus that has caused large outbreaks of severe illness in both horses and humans. New approaches are needed to rapidly infer the origin of a newly discovered VEEV strain, estimate its equine amplification and resultant epidemic potential, and predict human virulence phenotype. We performed whole genome single nucleotide polymorphism (SNP) analysis of all available VEE antigenic complex genomes, verified that a SNP-based phylogeny accurately captured the features of a phylogenetic tree based on multiple sequence alignment, and developed a high resolution genome-wide SNP microarray. We used the microarray to analyze a broadmore » panel of VEEV isolates, found excellent concordance between array- and sequence-based SNP calls, genotyped unsequenced isolates, and placed them on a phylogeny with sequenced genomes. The microarray successfully genotyped VEEV directly from tissue samples of an infected mouse, bypassing the need for viral isolation, culture and genomic sequencing. Lastly, we identified genomic variants associated with serotypes and host species, revealing a complex relationship between genotype and phenotype.« less

  8. Human Tick-Borne Encephalitis and Characterization of Virus from Biting Tick.

    PubMed

    Henningsson, Anna J; Lindqvist, Richard; Norberg, Peter; Lindblom, Pontus; Roth, Anette; Forsberg, Pia; Bergström, Tomas; Överby, Anna K; Lindgren, Per-Eric

    2016-08-01

    We report a case of human tick-borne encephalitis (TBE) in which the TBE virus was isolated from the biting tick. Viral growth and sequence were characterized and compared with those of a reference strain. Virus isolation from ticks from patients with TBE may offer a new approach for studies of epidemiology and pathogenicity. PMID:27434395

  9. Human Tick-Borne Encephalitis and Characterization of Virus from Biting Tick

    PubMed Central

    Lindqvist, Richard; Norberg, Peter; Lindblom, Pontus; Roth, Anette; Forsberg, Pia; Bergström, Tomas; Överby, Anna K.; Lindgren, Per-Eric

    2016-01-01

    We report a case of human tick-borne encephalitis (TBE) in which the TBE virus was isolated from the biting tick. Viral growth and sequence were characterized and compared with those of a reference strain. Virus isolation from ticks from patients with TBE may offer a new approach for studies of epidemiology and pathogenicity. PMID:27434395

  10. A conserved predicted pseudoknot in the NS2A-encoding sequence of West Nile and Japanese encephalitis flaviviruses suggests NS1' may derive from ribosomal frameshifting

    PubMed Central

    Firth, Andrew E; Atkins, John F

    2009-01-01

    Japanese encephalitis, West Nile, Usutu and Murray Valley encephalitis viruses form a tight subgroup within the larger Flavivirus genus. These viruses utilize a single-polyprotein expression strategy, resulting in ~10 mature proteins. Plotting the conservation at synonymous sites along the polyprotein coding sequence reveals strong conservation peaks at the very 5' end of the coding sequence, and also at the 5' end of the sequence encoding the NS2A protein. Such peaks are generally indicative of functionally important non-coding sequence elements. The second peak corresponds to a predicted stable pseudoknot structure whose biological importance is supported by compensatory mutations that preserve the structure. The pseudoknot is preceded by a conserved slippery heptanucleotide (Y CCU UUU), thus forming a classical stimulatory motif for -1 ribosomal frameshifting. We hypothesize, therefore, that the functional importance of the pseudoknot is to stimulate a portion of ribosomes to shift -1 nt into a short (45 codon), conserved, overlapping open reading frame, termed foo. Since cleavage at the NS1-NS2A boundary is known to require synthesis of NS2A in cis, the resulting transframe fusion protein is predicted to be NS1-NS2AN-term-FOO. We hypothesize that this may explain the origin of the previously identified NS1 'extension' protein in JEV-group flaviviruses, known as NS1'. PMID:19196463

  11. Evidence and rationale for the World Health Organization recommended standards for Japanese encephalitis surveillance

    PubMed Central

    2009-01-01

    Background Japanese encephalitis (JE) is the most important form of viral encephalitis in Asia. Surveillance for the disease in many countries has been limited. To improve collection of accurate surveillance data in order to increase understanding of the full impact of JE and monitor control programs, World Health Organization (WHO) Recommended Standards for JE Surveillance have been developed. To aid acceptance of the Standards, we describe the process of development, provide the supporting evidence, and explain the rationale for the recommendations made in the document. Methods A JE Core Working Group was formed in 2002 and worked on development of JE surveillance standards. A series of questions on specific topics was initially developed. A literature review was undertaken and the findings were discussed and documented. The group then prepared a draft document, with emphasis placed on the feasibility of implementation in Asian countries. A field test version of the Standards was published by WHO in January 2006. Feedback was then sought from countries that piloted the Standards and from public health professionals in forums and individual meetings to modify the Standards accordingly. Results After revisions, a final version of the JE surveillance standards was published in August 2008. The supporting information is presented here together with explanations of the rationale and levels of evidence for specific recommendations. Conclusion Provision of the supporting evidence and rationale should help to facilitate successful implementation of the JE surveillance standards in JE-endemic countries which will in turn enable better understanding of disease burden and the impact of control programs. PMID:20038298

  12. CSF herpes virus and autoantibody profiles in the evaluation of encephalitis

    PubMed Central

    Linnoila, Jenny J.; Binnicker, Matthew J.; Majed, Masoud; Klein, Christopher J.

    2016-01-01

    Objective: To report the frequency of coexisting herpes viruses (herpes simplex virus 1 [HSV-1] or HSV-2, varicella zoster virus, Epstein-Barr virus [EBV], cytomegalovirus, or human herpes virus 6 [HHV-6]) and autoantibodies in patients with encephalitis (herpes or autoimmune) in clinical laboratory service. Methods: Three groups were evaluated for herpes viruses and antibodies: group 1—patients whose CSF was positive for a herpes virus by real-time PCR over a period of 6 months; group 2—patients whose CSF was positive for an autoimmune encephalitis–associated antibody over 5 years (e.g., NMDA receptor [NMDA-R] antibody), and the same number of controls without autoimmune/infectious disease; and group 3—incidental autoimmune parainfectious encephalitis cases encountered over 1 year. Results: In group 1, antibodies were detected in 27 of 100 herpes PCR-positive CSF specimens (CSFs), either unclassified neural or nonneural in all but one patient with NMDA-R antibody detected after EBV infection. Antibodies were also detected in 3 of 7 CSFs submitted for repeat PCR testing (unclassified, 2; AMPA receptor, 1). In group 2, herpes viruses were detected in 1 of 77 controls (HHV-6) and 4 of 77 patients with autoimmune encephalitis (EBV, 2; HHV-6, 2); autoantibodies targeted NMDA-R in 3/4 and GABAB-R in 1/4. In group 3, NMDA-R antibody was detected in 7 patients post–HSV-1 encephalitis. Of the remaining 3 patients, 2 had unclassified neural antibodies detected, and one had GABAB-R autoimmunity. Concomitant neoplasms were discovered in 2 patients each from groups 2 and 3. Conclusions: Autoantibodies and herpes virus DNA frequently coexist in encephalitic CSF. Some patients develop parainfectious autoimmunity following viral CNS infection (usually HSV-1 encephalitis). The significance of detecting herpes nucleic acids in others remains unclear. PMID:27308306

  13. Nucleoside inhibitors of tick-borne encephalitis virus.

    PubMed

    Eyer, Luděk; Valdés, James J; Gil, Victor A; Nencka, Radim; Hřebabecký, Hubert; Šála, Michal; Salát, Jiří; Černý, Jiří; Palus, Martin; De Clercq, Erik; Růžek, Daniel

    2015-09-01

    Tick-borne encephalitis virus (TBEV) is a leading cause of human neuroinfections in Europe and Northeast Asia. There are no antiviral therapies for treating TBEV infection. A series of nucleoside analogues was tested for the ability to inhibit the replication of TBEV in porcine kidney cells and human neuroblastoma cells. The interactions of three nucleoside analogues with viral polymerase were simulated using advanced computational methods. The nucleoside analogues 7-deaza-2'-C-methyladenosine (7-deaza-2'-CMA), 2'-C-methyladenosine (2'-CMA), and 2'-C-methylcytidine (2'-CMC) inhibited TBEV replication. These compounds showed dose-dependent inhibition of TBEV-induced cytopathic effects, TBEV replication (50% effective concentrations [EC50]of 5.1 ± 0.4 μM for 7-deaza-2'-CMA, 7.1 ± 1.2 μM for 2'-CMA, and 14.2 ± 1.9 μM for 2'-CMC) and viral antigen production. Notably, 2'-CMC was relatively cytotoxic to porcine kidney cells (50% cytotoxic concentration [CC50] of ∼50 μM). The anti-TBEV effect of 2'-CMA in cell culture diminished gradually after day 3 posttreatment. 7-Deaza-2'-CMA showed no detectable cellular toxicity (CC50 > 50 μM), and the antiviral effect in culture was stable for >6 days posttreatment. Computational molecular analyses revealed that compared to the other two compounds, 7-deaza-2'-CMA formed a large cluster near the active site of the TBEV polymerase. High antiviral activity and low cytotoxicity suggest that 7-deaza-2'-CMA is a promising candidate for further investigation as a potential therapeutic agent in treating TBEV infection. PMID:26124166

  14. Nucleoside Inhibitors of Tick-Borne Encephalitis Virus

    PubMed Central

    Eyer, Luděk; Valdés, James J.; Gil, Victor A.; Nencka, Radim; Hřebabecký, Hubert; Šála, Michal; Salát, Jiří; Černý, Jiří; Palus, Martin; De Clercq, Erik

    2015-01-01

    Tick-borne encephalitis virus (TBEV) is a leading cause of human neuroinfections in Europe and Northeast Asia. There are no antiviral therapies for treating TBEV infection. A series of nucleoside analogues was tested for the ability to inhibit the replication of TBEV in porcine kidney cells and human neuroblastoma cells. The interactions of three nucleoside analogues with viral polymerase were simulated using advanced computational methods. The nucleoside analogues 7-deaza-2′-C-methyladenosine (7-deaza-2′-CMA), 2′-C-methyladenosine (2′-CMA), and 2′-C-methylcytidine (2′-CMC) inhibited TBEV replication. These compounds showed dose-dependent inhibition of TBEV-induced cytopathic effects, TBEV replication (50% effective concentrations [EC50]of 5.1 ± 0.4 μM for 7-deaza-2′-CMA, 7.1 ± 1.2 μM for 2′-CMA, and 14.2 ± 1.9 μM for 2′-CMC) and viral antigen production. Notably, 2′-CMC was relatively cytotoxic to porcine kidney cells (50% cytotoxic concentration [CC50] of ∼50 μM). The anti-TBEV effect of 2′-CMA in cell culture diminished gradually after day 3 posttreatment. 7-Deaza-2′-CMA showed no detectable cellular toxicity (CC50 > 50 μM), and the antiviral effect in culture was stable for >6 days posttreatment. Computational molecular analyses revealed that compared to the other two compounds, 7-deaza-2′-CMA formed a large cluster near the active site of the TBEV polymerase. High antiviral activity and low cytotoxicity suggest that 7-deaza-2′-CMA is a promising candidate for further investigation as a potential therapeutic agent in treating TBEV infection. PMID:26124166

  15. Phase III Clinical Trials Comparing the Immunogenicity and Safety of the Vero Cell-Derived Japanese Encephalitis Vaccine Encevac with Those of Mouse Brain-Derived Vaccine by Using the Beijing-1 Strain

    PubMed Central

    Miyazaki, Chiaki; Okada, Kenji; Ozaki, Takao; Hirose, Mizuo; Iribe, Kaneshige; Ishikawa, Yuji; Togashi, Takehiro; Ueda, Kohji

    2014-01-01

    The immunogenicity and safety of an inactivated cell culture Japanese encephalitis vaccine (CC-JEV) were compared with those of an inactivated mouse brain-derived Japanese encephalitis vaccine (MB-JEV) in phase III clinical multicenter trials conducted in children. The vaccines contain the same Japanese encephalitis virus strain, the Beijing-1 strain. Two independent clinical trials (trials 1 and 2) were conducted. Trial 1 was conducted in 468 healthy children. Each subject was injected with 17 μg per dose of either CC-JEV or MB-JEV, and the immunogenicity and safety of the vaccines were investigated. Trial 1 showed that CC-JEV was more immunogenic and reactive than MB-JEV at the same dose. Therefore, to adjust the immunogenicity of CC-JEV to that of MB-JEV, a vaccine that has had a good track record regarding its efficacy for a long time, trial 2 was conducted in 484 healthy children. To improve the stability, CC-JEV was converted from a liquid type to a freeze-dried type of vaccine. Each subject was injected subcutaneously with either 4 μg per dose of CC-JEV, 8 μg per dose of CC-JEV, or 17 μg per dose of MB-JEV twice, at an interval of 2 to 4 weeks, followed by an additional booster immunization 1 to 15 months after the primary immunization. Based on the results of trial 2, 4 μg per dose of the freeze-dried CC-JEV (under the label Encevac) was selected as a substitute for the MB-JEV. Encevac was approved and launched in 2011 and has since been in use as a 2nd-generation Japanese encephalitis vaccine in Japan. (These studies have been registered at the JapicCTI under registration no. JapicCTI-132063 and JapicCTI-080586 for trials 1 and 2, respectively.) PMID:24334689

  16. Subclinical infection without encephalitis in mice following intranasal exposure to Nipah virus-Malaysia and Nipah virus-Bangladesh

    PubMed Central

    2014-01-01

    Background Nipah virus and Hendra virus are closely related and following natural or experimental exposure induce similar clinical disease. In humans, encephalitis is the most serious outcome of infection and, hitherto, research into the pathogenesis of henipavirus encephalitis has been limited by the lack of a suitable model. Recently we reported a wild-type mouse model of Hendra virus (HeV) encephalitis that should facilitate detailed investigations of its neuropathogenesis, including mechanisms of disease recrudescence. In this study we investigated the possibility of developing a similar model of Nipah virus encephalitis. Findings Aged and young adult wild type mice did not develop clinical disease including encephalitis following intranasal exposure to either the Malaysia (NiV-MY) or Bangladesh (NiV-BD) strains of Nipah virus. However viral RNA was detected in lung tissue of mice at euthanasia (21 days following exposure) accompanied by a non-neutralizing antibody response. In a subsequent time course trial this viral RNA was shown to be reflective of an earlier self-limiting and subclinical lower respiratory tract infection through successful virus re-isolation and antigen detection in lung. There was no evidence for viremia or infection of other organs, including brain. Conclusions Mice develop a subclinical self-limiting lower respiratory tract infection but not encephalitis following intranasal exposure to NiV-BD or NiV-MY. These results contrast with those reported for HeV under similar exposure conditions in mice, demonstrating a significant biological difference in host clinical response to exposure with these viruses. This finding provides a new platform from which to explore the viral and/or host factors that determine the neuroinvasive ability of henipaviruses. PMID:24890603

  17. Anti-inflammatory activity of intravenous immunoglobulins protects against West Nile virus encephalitis

    PubMed Central

    Srivastava, Ruchi; Ramakrishna, Chandran

    2015-01-01

    West Nile virus (WNV), an important global human pathogen, targets neurons to cause lethal encephalitis, primarily in elderly and immunocompromised patients. Currently, there are no approved therapeutic agents or vaccines to treat WNV encephalitis. Recent studies have suggested that inflammation is a major contributor to WNV encephalitis morbidity. In this study we evaluated the use of IVIG (intravenous immunoglobulins – a clinical product comprising pooled human IgG) as an anti-inflammatory treatment in a model of lethal WNV infection. We report here that IVIG and pooled human WNV convalescent sera (WNV-IVIG) inhibited development of lethal WNV encephalitis by suppressing central nervous system (CNS) infiltration by CD45high leukocytes. Pathogenic Ly6Chigh CD11b+ monocytes were the major infiltrating subset in the CNS of infected control mice, whereas IVIG profoundly reduced infiltration of these pathogenic Ly6Chigh monocytes into the CNS of infected mice. Interestingly, WNV-IVIG was more efficacious than IVIG in controlling CNS inflammation when mice were challenged with a high-dose inoculum (105 versus 104 p.f.u.) of WNV. Importantly, adsorption of WNV E-glycoprotein neutralizing antibodies did not abrogate IVIG protection, consistent with virus neutralization not being essential for IVIG protection. These findings confirmed the potent immunomodulatory activity of generic IVIG, and emphasized its potential as an effective immunotherapeutic drug for encephalitis and other virus induced inflammatory diseases. PMID:25667322

  18. A Model Immunization Programme to Control Japanese Encephalitis in Viet Nam

    PubMed Central

    Yen, Nguyen Thu; Hanh, Hoang Duc; Chang, Na Yoon; Duong, Tran Nhu; Gibbons, Robert V.; Marks, Florian; Thu, Nghiem Anh; Hong, Nguyen Minh; Park, Jin Kyung; Tuan, Pham Anh; Nisalak, Ananda; Clemens, John D.; Xu, Zhi-yi

    2015-01-01

    ABSTRACT In Viet Nam, an inactivated, mouse brain-derived vaccine for Japanese encephalitis (JE) has been given exclusively to ≤5 years old children in 3 paediatric doses since 1997. However, JE incidence remained high, especially among children aged 5-9 years. We conducted a model JE immunization programme to assess the feasibility and impact of JE vaccine administered to 1-9 year(s) children in 3 standard-dose regimen: paediatric doses for children aged <3 years and adult doses for those aged ≥3 years. Of the targeted children, 96.2% were immunized with ≥2 doses of the vaccine. Compared to the national immunization programme, JE incidence rate declined sharply in districts with the model programme (11.32 to 0.87 per 100,000 in pre-versus post-vaccination period). The rate of reduction was most significant in the 5-9 years age-group. We recommend a policy change to include 5-9 years old children in the catch-up immunization campaign and administer a 4th dose to those aged 5-9 years, who had received 3 doses of the vaccine during the first 2-3 years of life. PMID:25995736

  19. How environmental conditions impact mosquito ecology and Japanese encephalitis: an eco-epidemiological approach.

    PubMed

    Tian, Huai-Yu; Bi, Peng; Cazelles, Bernard; Zhou, Sen; Huang, Shan-Qian; Yang, Jing; Pei, Yao; Wu, Xiao-Xu; Fu, Shi-Hong; Tong, Shi-Lu; Wang, Huan-Yu; Xu, Bing

    2015-06-01

    Japanese encephalitis (JE) is one of the major vector-borne diseases in Southeast Asia and the Western Pacific region, posing a threat to human health. In rural and suburban areas, traditional rice farming and intensive pig breeding provide an ideal environment for both mosquito development and the transmission of JEV among human beings. Combining surveillance data for mosquito vectors, human JE cases, and environmental conditions in Changsha, China, 2004-2009, generalized threshold models were constructed to project the mosquito and JE dynamics. Temperature and rainfall were found to be closely associated with mosquito density at 1, and 4month lag, respectively. The two thresholds, maximum temperature of 22-23°C for mosquito development and minimum temperature of 25-26°C for JEV transmission, play key roles in the ecology of JEV. The model predicts that, in the upper regime, a 1g/m(3) increase in absolute humidity would on average increase human cases by 68-84%. A shift in mosquito species composition in 2007 was observed, and possibly caused by a drought. Effective predictive models could be used in risk management to provide early warnings for potential JE transmission. PMID:25771078

  20. Viral encephalitis of tilapia larvae: primary characterization of a novel herpes-like virus.

    PubMed

    Shlapobersky, Mark; Sinyakov, Michael S; Katzenellenbogen, Mark; Sarid, Ronit; Don, Jeremy; Avtalion, Ramy R

    2010-04-10

    We report here an outbreak of an acute disease that caused high mortality rate in laboratory-reared tilapia larvae. The disease was initially observed in inbred gynogenetic line of blue tilapia larvae (Oreochromis aureus) and could be transmitted to larvae of other tilapia species. Based on the clinical manifestation (a whirling syndrome), we refer to the disease as viral encephalitis of tilapia larvae. The disease-associated DNA virus is described and accordingly designated tilapia larvae encephalitis virus (TLEV). A primary morphological, biophysical and molecular characterization of TLEV is presented. By virtue of these properties, the newly discovered virus is a herpes-like virus. Phylogenetic analysis, albeit limited, confirms this assumption and places TLEV within the family of Herpesviridae and distantly from the families Alloherpesviridae and Iridoviridae. By using PCR with virus-specific primers, diseased larvae and adult TLEV carriers were also identified in tilapia delivered from external hatcheries. PMID:20117816

  1. Extensive Recruitment of Plasma Blasts to the Cerebrospinal Fluid in Toscana Virus Encephalitis

    PubMed Central

    Schirmer, Lucas; Wölfel, Silke; Georgi, Enrico; Ploner, Markus; Bauer, Barbara; Hemmer, Bernhard

    2015-01-01

    An unexpectedly extensive recruitment of B cells and plasma blasts to the cerebrospinal fluid (CSF) in a patient with Toscana virus (TOSV) encephalitis is described. Acute infection by TOSV was demonstrated by serological methods and by detection of TOSV-specific nucleic acid in the CSF by real-time polymerase chain reaction and sequencing. PMID:26393235

  2. Identification of Viruses in Cases of Pediatric Acute Encephalitis and Encephalopathy Using Next-Generation Sequencing.

    PubMed

    Kawada, Jun-Ichi; Okuno, Yusuke; Torii, Yuka; Okada, Ryo; Hayano, Satoshi; Ando, Shotaro; Kamiya, Yasuko; Kojima, Seiji; Ito, Yoshinori

    2016-01-01

    Acute encephalitis/encephalopathy is a severe neurological syndrome that is occasionally associated with viral infection. Comprehensive virus detection assays are desirable because viral pathogens have not been identified in many cases. We evaluated the utility of next-generation sequencing (NGS) for detecting viruses in clinical samples of encephalitis/encephalopathy patients. We first determined the sensitivity and quantitative performance of NGS by comparing the NGS-determined number of sequences of human herpesvirus-6 (HHV-6) in clinical serum samples with the HHV-6 load measured using real-time PCR. HHV-6 was measured as it occasionally causes neurologic disorders in children. The sensitivity of NGS for detection of HHV-6 sequences was equivalent to that of real-time PCR, and the number of HHV-6 reads was significantly correlated with HHV-6 load. Next, we investigated the ability of NGS to detect viral sequences in 18 pediatric patients with acute encephalitis/encephalopathy of unknown etiology. A large number of Coxsackievirus A9 and mumps viral sequences were detected in the cerebrospinal fluid of 2 and 1 patients, respectively. In addition, Torque teno virus and Pepper mild mottle viral sequences were detected in the sera of one patient each. These data indicate that NGS is useful for detection of causative viruses in patients with pediatric encephalitis/encephalopathy. PMID:27625312

  3. Attenuation of Tick-Borne Encephalitis Virus Using Large-Scale Random Codon Re-encoding

    PubMed Central

    de Fabritus, Lauriane; Nougairède, Antoine; Aubry, Fabien; Gould, Ernest A; de Lamballerie, Xavier

    2015-01-01

    Large-scale codon re-encoding (i.e. introduction of a large number of synonymous mutations) is a novel method of generating attenuated viruses. Here, it was applied to the pathogenic flavivirus, tick-borne encephalitis virus (TBEV) which causes febrile illness and encephalitis in humans in forested regions of Europe and Asia. Using an infectious clone of the Oshima 5–10 strain ("wild-type virus"), a cassette of 1.4kb located in the NS5 coding region, was modified by randomly introducing 273 synonymous mutations ("re-encoded virus"). Whilst the in cellulo replicative fitness of the re-encoded virus was only slightly reduced, the re-encoded virus displayed an attenuated phenotype in a laboratory mouse model of non-lethal encephalitis. Following intra-peritoneal inoculation of either 2.105 or 2.106 TCID50 of virus, the frequency of viraemia, neurovirulence (measured using weight loss and appearance of symptoms) and neuroinvasiveness (detection of virus in the brain) were significantly decreased when compared with the wild-type virus. Mice infected by wild-type or re-encoded viruses produced comparable amounts of neutralising antibodies and results of challenge experiments demonstrated that mice previously infected with the re-encoded virus were protected against subsequent infection by the wild-type virus. This constitutes evidence that a mammalian species can be protected against infection by a virulent wild-type positive-stranded RNA virus following immunisation with a derived randomly re-encoded strain. Our results demonstrate that random codon re-encoding is potentially a simple and effective method of generating live-attenuated vaccine candidates against pathogenic flaviviruses. PMID:25734338

  4. Eco-friendly larvicides from Indian plants: Effectiveness of lavandulyl acetate and bicyclogermacrene on malaria, dengue and Japanese encephalitis mosquito vectors.

    PubMed

    Govindarajan, Marimuthu; Benelli, Giovanni

    2016-11-01

    Mosquitoes (Diptera: Culicidae) are a key threat for millions of people and animals worldwide, since they act as vectors for devastating pathogens and parasites, including malaria, dengue, Japanese encephalitis, filiariasis and Zika virus. Mosquito young instars are usually targeted using organophosphates, insect growth regulators and microbial agents. Indoor residual spraying and insecticide-treated bed nets are also employed. However, these chemicals have negative effects on human health and the environment and induce resistance in a number of vectors. In this scenario, newer and safer tools have been recently implemented to enhance mosquito control. The concrete potential of screening plant species as sources of metabolites for entomological and parasitological purposes is worthy of attention, as recently elucidated by the Y. Tu's example. Here we investigated the toxicity of Heracleum sprengelianum (Apiaceae) leaf essential oil and its major compounds toward third instar larvae of the malaria vector Anopheles subpictus, the arbovirus vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. GC-MS analysis showed that EO major components were lavandulyl acetate (17.8%) and bicyclogermacrene (12.9%). The EO was toxic to A. subpictus, A. albopictus, and C. tritaeniorhynchus, with LC50 of 33.4, 37.5 and 40.9µg/ml, respectively. Lavandulyl acetate was more toxic to mosquito larvae if compared to bicyclogermacrene. Their LC50 were 4.17 and 10.3µg/ml for A. subpictus, 4.60 and 11.1µg/ml for A. albopictus, 5.11 and 12.5µg/ml for C. tritaeniorhynchus. Notably, the EO and its major compounds were safer to three non-target mosquito predators, Anisops bouvieri, Diplonychus indicus and Gambusia affinis, with LC50 ranging from 206 to 4219µg/ml. Overall, this study highlights that H. sprengelianum EO is a promising source of eco-friendly larvicides against three important mosquito vectors with moderate toxicity against non-target aquatic

  5. [Serological evidence of St. Louis encephalitis virus circulation in birds from Buenos Aires City, Argentina].

    PubMed

    Beltrán, Fernando J; Díaz, Luis A; Konigheim, Brenda; Molina, José; Beaudoin, Juan B; Contigiani, Marta; Spinsanti, Lorena I

    2015-01-01

    Our goal was to determine the presence of neutralizing antibodies against St. Louis encephalitis virus (SLEV) and West Nile virus (WNV) in sera of wild and domestic birds from Buenos Aires City, Argentina. From October 2012 to April 2013, 180 samples were collected and processed by the microneutralization technique. A 7.2% of the sampled birds were seropositive for SLEV, while no seropositive birds for WNV were detected. PMID:26627114

  6. Multiple-Insecticide Resistance and Classic Gene Mutations to Japanese Encephalitis Vector Culex tritaeniorhynchus from China.

    PubMed

    Wu, Zhi-Ming; Chu, Hong-Liang; Wang, Gang; Zhu, Xiao-Juan; Guo, Xiao-Xia; Zhang, Ying-Mei; Xing, Dan; Yan, Ting; Zhao, Ming-Hui; Dong, Yan-De; Li, Chun-Xiao; Zhao, Tong-Yan

    2016-06-01

    Widespread resistance of insect pests to insecticides has been widely reported in China and there is consequently an urgent need to adjust pest management strategies appropriately. This requires detailed information on the extent and causes of resistance. The aim of the present study was to investigate levels of resistance to 5 insecticides among 12 strains of Culex tritaeniorhynchus, a major vector of Japanese encephalitis in China. Resistance to deltamethrin, beta-cypermethrin, permethrin, dichlorvos, and propoxur were measured using larval bioassays. The allelic frequency of knockdown resistance (kdr) and acetylcholinesterase (AChE) mutations were determined in all strains. Larval bioassay results indicated that the field strains collected from different sites were resistant to deltamethrin, beta-cypermethrin, permethrin, dichlorvos, and propoxur, with resistance ratio values ranging from 1.70- to 71.98-fold, 7.83- to 43.07-fold, 3.54- to 40.03-fold, 291.85- to 530.89-fold, and 51.32- to 108.83-fold, respectively. A polymerase chain reaction amplification of specific alleles method for individual was developed to detect genotypes of the AChE gene mutation F455W in Cx. tritaeniorhynchus. The frequency of the AChE gene mutation F455W was 100.00% in all strains, making this mutation of no value as a marker of resistance to organophosphorous and carbamate pesticides in Cx. tritaeniorhynchus in China. The kdr allele was present in all strains at frequencies of 10.00-29.55%. Regression analysis indicated a significant correlation between kdr allele frequencies and levels of resistance to deltamethrin, beta-cypermethrin, and permethrin. These results highlight the need to monitor and map insecticide resistance in Cx. tritaeniorhynchus and to adjust pesticide use to minimize the development of resistance in these mosquitoes. PMID:27280353

  7. Cost-effectiveness of routine immunization to control Japanese encephalitis in Shanghai, China.

    PubMed Central

    Ding, Ding; Kilgore, Paul E.; Clemens, John D.; Wei, Liu; Zhi-Yi, Xu

    2003-01-01

    OBJECTIVE: To assess the cost-effectiveness of inactivated and live attenuated Japanese encephalitis (JE) vaccines given to infants and children in Shanghai. METHODS: A decision-analytical model was constructed in order to compare costs and outcomes for three hypothetical cohorts of 100,000 children followed from birth in 1997 to the age of 30 years who received either no JE vaccine, inactivated JE vaccine (P3), or live attenuated JE vaccine (SA 14-14-2). Cumulative incidences of JE from birth to 30 years of age in the pre-immunization era, i.e. before 1968, were used to estimate expected rates of JE in the absence of vaccination. The economic consequences were measured as cost per case, per death, and per disability-adjusted life year (DALY) averted for the two JE immunization programmes. FINDINGS: In comparison with no JE immunization, a programme using the P3 vaccine would prevent 420 JE cases and 105 JE deaths and would save 6456 DALYs per 100,000 persons; the use of the SA 14-14-2 vaccine would prevent 427 cases and 107 deaths and would save 6556 DALYs per 100,000 persons. Both kinds of immunization were cost saving but the SA 14-14-2 vaccine strategy resulted in a saving that was 47% greater (512,456 US dollars) than that obtained with the P3 vaccine strategy (348,246 US dollars). CONCLUSION: Both JE immunization strategies resulted in cost savings in comparison with no JE immunization. This provides a strong economic rationale for vaccinating against JE in Shanghai and suggests that vaccination against JE might be economically justifiable in other parts of China and in certain other developing countries of Asia where the disease is endemic. PMID:12856051

  8. The three subtypes of tick-borne encephalitis virus induce encephalitis in a natural host, the bank vole (Myodes glareolus).

    PubMed

    Tonteri, Elina; Kipar, Anja; Voutilainen, Liina; Vene, Sirkka; Vaheri, Antti; Vapalahti, Olli; Lundkvist, Åke

    2013-01-01

    Tick-borne encephalitis virus (TBEV) infects bank voles (Myodes glareolus) in nature, but the relevance of rodents for TBEV transmission and maintenance is unclear. We infected colonized bank voles subcutaneously to study and compare the infection kinetics, acute infection, and potential viral persistence of the three known TBEV subtypes: European (TBEV-Eur), Siberian (TBEV-Sib) and Far Eastern (TBEV-FE). All strains representing the three subtypes were infective and highly neurotropic. They induced (meningo)encephalitis in some of the animals, however most of the cases did not present with apparent clinical symptoms. TBEV-RNA was cleared significantly slower from the brain as compared to other organs studied. Supporting our earlier findings in natural rodent populations, TBEV-RNA could be detected in the brain for up to 168 days post infection, but we could not demonstrate infectivity by cell culture isolation. Throughout all time points post infection, RNA of the TBEV-FE was detected significantly more often than RNA of the other two strains in all organs studied. TBEV-FE also induced prolonged viremia, indicating distinctive kinetics in rodents in comparison to the other two subtypes. This study shows that bank voles can develop a neuroinvasive TBEV infection with persistence of viral RNA in brain, and mount an anti-TBEV IgG response. The findings also provide further evidence that bank voles can serve as sentinels for TBEV endemicity. PMID:24349041

  9. The Three Subtypes of Tick-Borne Encephalitis Virus Induce Encephalitis in a Natural Host, the Bank Vole (Myodes glareolus)

    PubMed Central

    Tonteri, Elina; Kipar, Anja; Voutilainen, Liina; Vene, Sirkka; Vaheri, Antti; Vapalahti, Olli; Lundkvist, Åke

    2013-01-01

    Tick-borne encephalitis virus (TBEV) infects bank voles (Myodes glareolus) in nature, but the relevance of rodents for TBEV transmission and maintenance is unclear. We infected colonized bank voles subcutaneously to study and compare the infection kinetics, acute infection, and potential viral persistence of the three known TBEV subtypes: European (TBEV-Eur), Siberian (TBEV-Sib) and Far Eastern (TBEV-FE). All strains representing the three subtypes were infective and highly neurotropic. They induced (meningo)encephalitis in some of the animals, however most of the cases did not present with apparent clinical symptoms. TBEV-RNA was cleared significantly slower from the brain as compared to other organs studied. Supporting our earlier findings in natural rodent populations, TBEV-RNA could be detected in the brain for up to 168 days post infection, but we could not demonstrate infectivity by cell culture isolation. Throughout all time points post infection, RNA of the TBEV-FE was detected significantly more often than RNA of the other two strains in all organs studied. TBEV-FE also induced prolonged viremia, indicating distinctive kinetics in rodents in comparison to the other two subtypes. This study shows that bank voles can develop a neuroinvasive TBEV infection with persistence of viral RNA in brain, and mount an anti-TBEV IgG response. The findings also provide further evidence that bank voles can serve as sentinels for TBEV endemicity. PMID:24349041

  10. Visual detection of murray valley encephalitis virus by reverse transcription loop-mediated isothermal amplification.

    PubMed

    Gong, Rui; Wang, Han Hua; Qin, Hong; Guo, Xiao Ping; Ma, Xue Jun

    2015-03-01

    A sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for rapid visual detection of Murray valley encephalitis virus (MVEV) infection. The reaction was performed in one step in a single tube at 63 °C for 60 min with the addition of the hydroxynaphthol blue (HNB) dye prior to amplification. The detection limit of the RT-LAMP assay was 100 copies per reaction based on 10-fold dilutions of in vitro transcribed RNA derived from a synthetic MVEV DNA template. No cross-reaction was observed with other encephalitis-associated viruses. The assay was further evaluated using spiked cerebrospinal fluid sample with pseudotype virus containing the NS5 gene of MVEV. PMID:25800449

  11. Herpes Simplex Virus-1 Encephalitis in Adults: Pathophysiology, Diagnosis, and Management.

    PubMed

    Bradshaw, Michael J; Venkatesan, Arun

    2016-07-01

    Herpetic infections have plagued humanity for thousands of years, but only recently have advances in antiviral medications and supportive treatments equipped physicians to combat the most severe manifestations of disease. Prompt recognition and treatment can be life-saving in the care of patients with herpes simplex-1 virus encephalitis, the most commonly identified cause of sporadic encephalitis worldwide. Clinicians should be able to recognize the clinical signs and symptoms of the infection and familiarize themselves with a rational diagnostic approach and therapeutic modalities, as early recognition and treatment are key to improving outcomes. Clinicians should also be vigilant for the development of acute complications, including cerebral edema and status epilepticus, as well as chronic complications, including the development of autoimmune encephalitis associated with antibodies to the N-methyl-D-aspartate receptor and other neuronal cell surface and synaptic epitopes. Herein, we review the pathophysiology, differential diagnosis, and clinical and radiological features of herpes simplex virus-1 encephalitis in adults, including a discussion of the most common complications and their treatment. While great progress has been made in the treatment of this life-threatening infection, a majority of patients will not return to their previous neurologic baseline, indicating the need for further research efforts aimed at improving the long-term sequelae. PMID:27106239

  12. Japanese encephalitis (JE). Part I: clinical profile of 1,282 adult acute cases of four epidemics.

    PubMed

    Sarkari, N B S; Thacker, A K; Barthwal, S P; Mishra, V K; Prapann, Shiv; Srivastava, Deepak; Sarkari, M

    2012-01-01

    Japanese encephalitis (JE) is numerically the most important global cause of encephalitis and so far confirmed to have caused major epidemics in India. Most of the reported studies have been in children. This largest study involving only adults, belonging to four epidemics, is being reported from Gorakhpur. The aim of this study is to detail the acute clinical profile (not viral) outcome and to classify the sequelae at discharge. This prospective study involved 1,282 adult patients initially diagnosed as JE admitted during the epidemics of 1978, 1980, 1988, and 1989, on identical clinical presentation and CSF examination. In the meantime, the diagnosis of JE was confirmed by serological and/or virological studies in only a representative number of samples (649 of 1,282 cases). Eighty-three left against medical advice (LAMA) at various stages, so 1,199 of 1,282 were available for the study. Peak incidence of [1,061 of 1,282 (83%)] of clinically suspected cases was from September 15 to November 2. Serum IgM and IgG were positive in high titers in 50.87% (330 of 649) and IgM positive in CSF in 88.75% (109 of 123) of the cases. JE virus could be isolated from CSF and brain tissue in 5 of 5 and 4 of 5 samples, respectively. Altered sensorium (AS) in (96%), convulsions (86%), and headache (85%) were the main symptoms for hospitalization by the third day of the onset. Other neurological features included hyperkinetic movements in 593 of 1,282 (46%)-choreoathetoid in 490 (83%) and bizarre, ill-defined in 103 (17%). The features of brain stem involvement consisted of opsoclonus (20%), gaze palsies (16%), and pupillary changes (48%) with waxing and waning character. Cerebellar signs were distinctly absent. Dystonia and decerebrate rigidity was observed in 43 and 6%, respectively, paralytic features in 17% and seizures in 30%. Many non-neurological features of prognostic importance included abnormal breathing patterns (ABP) (45%), pulmonary edema (PO) (33%), and upper

  13. Isolation and characterization of tick-borne encephalitis virus from Ixodes persulcatus in Mongolia in 2012.

    PubMed

    Muto, Memi; Bazartseren, Boldbaatar; Tsevel, Bazartseren; Dashzevge, Erdenechimeg; Yoshii, Kentaro; Kariwa, Hiroaki

    2015-07-01

    Tick-borne encephalitis virus (TBEV) is a zoonotic virus belonging to the genus Flavivirus, in the family Flaviviridae. The virus, which is endemic in Europe and northern parts of Asia, causes severe encephalitis. Tick-borne encephalitis (TBE) has been reported in Mongolia since the 1980s, but details about the biological characteristics of the endemic virus are lacking. In this study, 680 ticks (Ixodes persulcatus) were collected in Selenge aimag, northern Mongolia, in 2012. Nine Mongolian TBEV strains were isolated from tick homogenates. A sequence analysis of the envelope protein gene revealed that all isolates belonged to the Siberian subtype of TBEV. Two strains showed similar growth properties in cultured cells, but their virulence in mice differed. Whole genome sequencing revealed only thirteen amino acid differences between these Mongolian TBEV strains. Our results suggest that these naturally occurring amino acid mutations affected the pathogenicity of Mongolian TBEV. Our results may be an important platform for monitoring TBEV to evaluate the epidemiological risk in TBE endemic areas of Mongolia. PMID:26025267

  14. Japanese Encephalitis in Assam, India: Need to Increase Healthcare Workers’ Understanding to Improve Health Care

    PubMed Central

    Ahmad, Akram; Khan, Muhammad Umair; Gogoi, Lakhya Jyoti; Kalita, Manabendra; Sikdar, Atul Prasad; Pandey, Sureshwar; Dhingra, Sameer

    2015-01-01

    Introduction Japanese encephalitis (JE) is a major cause of high morbidity and mortality in several states across India. However, in 2014, a sharp rise was observed in the number of cases of JE in north-eastern Assam state, and 51% of the total cases of JE in India were reported from the Assam in the same year. In this regard, a study was conducted to evaluate the knowledge and attitudes of healthcare workers in Darrang, a district of Assam highly affected by JE. Methods A cross sectional study was conducted for 2 months among HCWs in the major district hospital of Darrang, Assam. A pre-tested, self-administered questionnaire was used to collect data from the participants. Convenience sampling approach was used to collect data from different departments of the hospitals. Descriptive and logistic regression analyses were used to express the results. Results The knowledge of HCWs regarding JE was poor with a mean knowledge score of 11.02±2.39 (out of 17), while their attitudes were positive with a mean attitudes score of 43.16± 2.47 (ranging from 13 to 52). Overall, 40.4% and 74.3% of participants demonstrated good knowledge and positive attitudes respectively. Cut-off score for good knowledge and positive attitudes toward JE was set as ≥12 and >40 respectively. Older participants (40–49 years) and experienced workers (>10 years) were significantly associated with good knowledge as compared to their referent group (p<0.05), while knowledge of nurses and other orderlies were significantly lower than physicians (p<0.01). Similar factors were associated with the positive attitudes of the participants with the exception of experience. Television was the major source of information regarding JE reported by HCWs (79%). Conclusion Although the knowledge was not optimized, HCWs exhibited positive attitudes towards JE. Future research is required to design, implement and evaluate interventions to improve the knowledge of JE among HCWs. PMID:26296212

  15. Anti-tick-borne encephalitis (TBE) virus neutralizing antibodies dynamics in natural infections versus vaccination.

    PubMed

    Remoli, Maria Elena; Marchi, Antonella; Fortuna, Claudia; Benedetti, Eleonora; Minelli, Giada; Fiorentini, Cristiano; Mel, Rosanna; Venturi, Giulietta; Ciufolini, Maria Grazia

    2015-03-01

    Tick-borne encephalitis (TBE) virus infection elicits a life-long lasting protection. However, little is known about the neutralizing antibodies titres following natural infection. In this study, subjects with past TBE disease (n = 62) were analysed for the presence and titre of anti-TBE neutralizing antibodies, and compared with a vaccinated cohort (n = 101). Neutralizing antibody titres were higher in individuals with past TBE and did not show an age-dependent decrease when compared with vaccinees. PMID:25722483

  16. Tick-Borne Encephalitis Virus-Neutralizing Antibodies in Different Immunoglobulin Preparations

    PubMed Central

    Rabel, Philip O.; Planitzer, Christina B.; Farcet, Maria R.

    2012-01-01

    Patients with primary immunodeficiency (PIDs) depend on the presence of a variety of antibody specificities in intravenous immunoglobulin (IVIG). Using the tick-borne encephalitis virus (TBEV), geographic variability in IVIG antibody content was shown. Care should therefore be exercised when treating PIDs in a given geography, as only locally sourced plasma contains the antibody specificities against the circulating pathogens in the given locality. PMID:22379062

  17. Chimeric Alphavirus Vaccine Candidates Protect Mice from Intranasal Challenge with Western Equine Encephalitis Virus

    PubMed Central

    Atasheva, Svetlana; Wang, Eryu; Adams, A. Paige; Plante, Kenneth S.; Ni, Sai; Taylor, Katherine; Miller, Mary E.; Frolov, Ilya; Weaver, Scott C.

    2011-01-01

    We developed two types of chimeric Sindbis virus (SINV)/western equine encephalitis virus (WEEV) alphaviruses to investigate their potential use as live virus vaccines against WEE. The first-generation vaccine candidate, SIN/CO92, was derived from structural protein genes of WEEV strain CO92-1356, and two second-generation candidates were derived from WEEV strain McMillan. For both first- and second-generation vaccine candidates, the nonstructural protein genes were derived from SINV strain AR339. Second-generation vaccine candidates SIN/SIN/McM and SIN/EEE/McM included the envelope glycoprotein genes from WEEV strain McMillan; however, the amino-terminal half of the capsid, which encodes the RNA-binding domain, was derived from either SINV or eastern equine encephalitis virus (EEEV) strain FL93-939. All chimeric viruses replicated efficiently in mammalian and mosquito cell cultures and were highly attenuated in 6-week-old mice. Vaccinated mice developed little or no detectable disease and showed little or no evidence of challenge virus replication; however, all developed high titers of neutralizing antibodies. Upon intranasal challenge with high doses of virulent WEEV strains, mice vaccinated with ≥105 PFU of SIN/CO92 or ≥104 PFU of SIN/SIN/McM or SIN/EEE/McM were completely protected from disease. These findings support the potential use of these live-attenuated vaccine candidates as safe and effective vaccines against WEE. PMID:19446595

  18. Virus-Neutralizing Monoclonal Antibody Expressed in Milk of Transgenic Mice Provides Full Protection against Virus-Induced Encephalitis

    PubMed Central

    Kolb, Andreas F.; Pewe, Lecia; Webster, John; Perlman, Stanley; Whitelaw, C. Bruce A.; Siddell, Stuart G.

    2001-01-01

    Neutralizing antibodies represent a major host defense mechanism against viral infections. In mammals, passive immunity is provided by neutralizing antibodies passed to the offspring via the placenta or the milk as immunoglobulin G and secreted immunoglobulin A. With the long-term goal of producing virus-resistant livestock, we have generated mice carrying transgenes that encode the light and heavy chains of an antibody that is able to neutralize the neurotropic JHM strain of murine hepatitis virus (MHV-JHM). MHV-JHM causes acute encephalitis and acute and chronic demyelination in susceptible strains of mice and rats. Transgene expression was targeted to the lactating mammary gland by using the ovine β-lactoglobulin promoter. Milk from these transgenic mice contained up to 0.7 mg of recombinant antibody/ml. In vitro analysis of milk derived from different transgenic lines revealed a linear correlation between antibody expression and virus-neutralizing activity, indicating that the recombinant antibody is the major determinant of MHV-JHM neutralization in murine milk. Offspring of transgenic and control mice were challenged with a lethal dose of MHV-JHM. Litters suckling nontransgenic dams succumbed to fatal encephalitis, whereas litters suckling transgenic dams were fully protected against challenge, irrespective of whether they were transgenic. This demonstrates that a single neutralizing antibody expressed in the milk of transgenic mice is sufficient to completely protect suckling offspring against MHV-JHM-induced encephalitis. PMID:11222704

  19. Genetic and Anatomic Determinants of Enzootic Venezuelan Equine Encephalitis Virus Infection of Culex (Melanoconion) taeniopus

    PubMed Central

    Kenney, Joan L.; Adams, A. Paige; Gorchakov, Rodion; Leal, Grace; Weaver, Scott C.

    2012-01-01

    Venezuelan equine encephalitis (VEE) is a re-emerging, mosquito-borne viral disease with the potential to cause fatal encephalitis in both humans and equids. Recently, detection of endemic VEE caused by enzootic strains has escalated in Mexico, Peru, Bolivia, Colombia and Ecuador, emphasizing the importance of understanding the enzootic transmission cycle of the etiologic agent, VEE virus (VEEV). The majority of work examining the viral determinants of vector infection has been performed in the epizootic mosquito vector, Aedes (Ochlerotatus) taeniorhynchus. Based on the fundamental differences between the epizootic and enzootic cycles, we hypothesized that the virus-vector interaction of the enzootic cycle is fundamentally different from that of the epizootic model. We therefore examined the determinants for VEEV IE infection in the enzootic vector, Culex (Melanoconion) taeniopus, and determined the number and susceptibility of midgut epithelial cells initially infected and their distribution compared to the epizootic virus-vector interaction. Using chimeric viruses, we demonstrated that the determinants of infection for the enzootic vector are different than those observed for the epizootic vector. Similarly, we showed that, unlike A. taeniorhynchus infection with subtype IC VEEV, C. taeniopus does not have a limited subpopulation of midgut cells susceptible to subtype IE VEEV. These findings support the hypothesis that the enzootic VEEV relationship with C. taeniopus differs from the epizootic virus-vector interaction in that the determinants appear to be found in both the nonstructural and structural regions, and initial midgut infection is not limited to a small population of susceptible cells. PMID:22509419

  20. The Ubiquitin Proteasome System Plays a Role in Venezuelan Equine Encephalitis Virus Infection

    PubMed Central

    Amaya, Moushimi; Keck, Forrest; Lindquist, Michael; Voss, Kelsey; Scavone, Lauren; Kehn-Hall, Kylene; Roberts, Brian; Bailey, Charles; Schmaljohn, Connie; Narayanan, Aarthi

    2015-01-01

    Many viruses have been implicated in utilizing or modulating the Ubiquitin Proteasome System (UPS) to enhance viral multiplication and/or to sustain a persistent infection. The mosquito-borne Venezuelan equine encephalitis virus (VEEV) belongs to the Togaviridae family and is an important biodefense pathogen and select agent. There are currently no approved vaccines or therapies for VEEV infections; therefore, it is imperative to identify novel targets for therapeutic development. We hypothesized that a functional UPS is required for efficient VEEV multiplication. We have shown that at non-toxic concentrations Bortezomib, a FDA-approved inhibitor of the proteasome, proved to be a potent inhibitor of VEEV multiplication in the human astrocytoma cell line U87MG. Bortezomib inhibited the virulent Trinidad donkey (TrD) strain and the attenuated TC-83 strain of VEEV. Additional studies with virulent strains of Eastern equine encephalitis virus (EEEV) and Western equine encephalitis virus (WEEV) demonstrated that Bortezomib is a broad spectrum inhibitor of the New World alphaviruses. Time-of-addition assays showed that Bortezomib was an effective inhibitor of viral multiplication even when the drug was introduced many hours post exposure to the virus. Mass spectrometry analyses indicated that the VEEV capsid protein is ubiquitinated in infected cells, which was validated by confocal microscopy and immunoprecipitation assays. Subsequent studies revealed that capsid is ubiquitinated on K48 during early stages of infection which was affected by Bortezomib treatment. This study will aid future investigations in identifying host proteins as potential broad spectrum therapeutic targets for treating alphavirus infections. PMID:25927990

  1. Venezuelan Equine Encephalitis Virus Induces Apoptosis through the Unfolded Protein Response Activation of EGR1

    PubMed Central

    Baer, Alan; Lundberg, Lindsay; Swales, Danielle; Waybright, Nicole; Pinkham, Chelsea; Dinman, Jonathan D.

    2016-01-01

    ABSTRACT Venezuelan equine encephalitis virus (VEEV) is a previously weaponized arthropod-borne virus responsible for causing acute and fatal encephalitis in animal and human hosts. The increased circulation and spread in the Americas of VEEV and other encephalitic arboviruses, such as eastern equine encephalitis virus and West Nile virus, underscore the need for research aimed at characterizing the pathogenesis of viral encephalomyelitis for the development of novel medical countermeasures. The host-pathogen dynamics of VEEV Trinidad donkey-infected human astrocytoma U87MG cells were determined by carrying out RNA sequencing (RNA-Seq) of poly(A) and mRNAs. To identify the critical alterations that take place in the host transcriptome following VEEV infection, samples were collected at 4, 8, and 16 h postinfection and RNA-Seq data were acquired using an Ion Torrent PGM platform. Differential expression of interferon response, stress response factors, and components of the unfolded protein response (UPR) was observed. The protein kinase RNA-like endoplasmic reticulum kinase (PERK) arm of the UPR was activated, as the expression of both activating transcription factor 4 (ATF4) and CHOP (DDIT3), critical regulators of the pathway, was altered after infection. Expression of the transcription factor early growth response 1 (EGR1) was induced in a PERK-dependent manner. EGR1−/− mouse embryonic fibroblasts (MEFs) demonstrated lower susceptibility to VEEV-induced cell death than isogenic wild-type MEFs, indicating that EGR1 modulates proapoptotic pathways following VEEV infection. The influence of EGR1 is of great importance, as neuronal damage can lead to long-term sequelae in individuals who have survived VEEV infection. IMPORTANCE Alphaviruses represent a group of clinically relevant viruses transmitted by mosquitoes to humans. In severe cases, viral spread targets neuronal tissue, resulting in significant and life-threatening inflammation dependent on a combination

  2. Malathion Resistance Status and Mutations in Acetylcholinesterase Gene (Ace) in Japanese Encephalitis and Filariasis Vectors from Endemic Area in India.

    PubMed

    Misra, Brij Ranjan; Gore, Milind

    2015-05-01

    Japanese encephalitis (JE) and lymphatic filariasis (LF) are endemic in estern part of Uttar Pradesh in India and transmitted by Culex mosquitoes (Diptera: Culicidae). JE vaccination and mass drug administration for JE and LF management is being undertaken respectively. In addition to this, indoor residual spraying and fogging are used for the control of mosquito vectors. Organophosphate resistance in mosquito is dependent on alteration in acetylcholinesterase (Ace) gene. Hence, it is important to evaluate organophosphate resistance in Culex tritaeniorhynchus Giles (JE vector) and Culex quinquefasciatus Say (LF vector). The current study showed the presence of resistant populations and F331W mutation in Cx. tritaeniorhynchus and G119S mutation in Cx. quinquefasciatus insensitive Ace genes. Resistant populations of these two vectors increase the chances of spreading of resistance in the natural population and may cause failure of intervention programs that include organophosphates against these two vectors in future. PMID:26334819

  3. Exposure of domestic mammals to West Nile virus during an outbreak of human encephalitis, New York City, 1999.

    PubMed Central

    Komar, N.; Panella, N. A.; Boyce, E.

    2001-01-01

    We evaluated West Nile (WN) virus seroprevalence in healthy horses, dogs, and cats in New York City after an outbreak of human WN virus encephalitis in 1999. Two (3%) of 73 horses, 10 (5%) of 189 dogs, and none of 12 cats tested positive for WN virus-neutralizing antibodies. Domestic mammals should be evaluated as sentinels for local WN virus activity and predictors of the infection in humans. PMID:11585540

  4. Venezuelan Equine Encephalitis Virus Activity in the Gulf Coast Region of Mexico, 2003–2010

    PubMed Central

    Adams, A. Paige; Navarro-Lopez, Roberto; Ramirez-Aguilar, Francisco J.; Lopez-Gonzalez, Irene; Leal, Grace; Flores-Mayorga, Jose M.; Travassos da Rosa, Amelia P. A.; Saxton-Shaw, Kali D.; Singh, Amber J.; Borland, Erin M.; Powers, Ann M.; Tesh, Robert B.; Weaver, Scott C.; Estrada-Franco, Jose G.

    2012-01-01

    Venezuelan equine encephalitis virus (VEEV) has been the causative agent for sporadic epidemics and equine epizootics throughout the Americas since the 1930s. In 1969, an outbreak of Venezuelan equine encephalitis (VEE) spread rapidly from Guatemala and through the Gulf Coast region of Mexico, reaching Texas in 1971. Since this outbreak, there have been very few studies to determine the northward extent of endemic VEEV in this region. This study reports the findings of serologic surveillance in the Gulf Coast region of Mexico from 2003–2010. Phylogenetic analysis was also performed on viral isolates from this region to determine whether there have been substantial genetic changes in VEEV since the 1960s. Based on the findings of this study, the Gulf Coast lineage of subtype IE VEEV continues to actively circulate in this region of Mexico and appears to be responsible for infection of humans and animals throughout this region, including the northern State of Tamaulipas, which borders Texas. PMID:23133685

  5. Effects of immunosuppression on encephalitis virus infection in the house finch, Carpodacus mexicanus.

    PubMed

    Reisen, William K; Chiles, Robert E; Green, Emily N; Fang, Ying; Mahmood, Farida; Martinez, Vincent M; Laver, Thomas

    2003-03-01

    Immunosuppression of house finches was attempted by blood feeding Culex tarsalis Coquillett mosquitoes or by injecting birds with the corticosteroid dexamethasone or the immunosuppressant drug cyclophosphamide before and after inoculation with western equine encephalomyelitis or St. Louis encephalitis viruses. Mosquito bites (8-37 females blood feeding on each bird over a 3-d period) did not enhance the viremia response or increase the frequency of chronic infection. In contrast, dexamethasone and cyclophosphamide enhanced the amplitude and duration of the viremia response, but had no consistent effect on the antibody responses as measured by enzyme immunoassay or plaque reduction neutralization assay. Elevated viremias were followed by increases in the frequency of chronic infections with St. Louis encephalitis, but not western equine encephalomyelitis. Immunosuppression may provide a useful tool to study the chronic infection process of flaviviruses in vertebrates. PMID:12693850

  6. Toscana Virus Encephalitis in a Traveler Returning to the United States

    PubMed Central

    Azar, Marwan M.; Landry, Marie L.; Shaw, Albert C.

    2015-01-01

    In Italy, Toscana virus is the most common cause of meningitis from May to October. Though only a few cases have been reported in U.S. travelers returning from Europe, most cases are likely unrecognized due to lack of familiarity with the disease. Here, we describe the case of an 82-year-old man presenting with fever, profound weakness, and hearing loss after returning to the United States following a 2-week summertime vacation in southern Italy who was ultimately diagnosed with Toscana virus encephalitis. This case should alert clinicians to the possibility of Toscana virus infection in returning travelers and provides information on how to obtain testing if Toscana virus is suspected. PMID:25673791

  7. Detection of West Nile virus and tick-borne encephalitis virus in birds in Slovakia, using a universal primer set.

    PubMed

    Csank, Tomáš; Bhide, Katarína; Bencúrová, Elena; Dolinská, Saskia; Drzewnioková, Petra; Major, Peter; Korytár, Ľuboš; Bocková, Eva; Bhide, Mangesh; Pistl, Juraj

    2016-06-01

    West Nile virus (WNV) is a mosquito-borne neurotropic pathogen that presents a major public health concern. Information on WNV prevalence and circulation in Slovakia is insufficient. Oral and cloacal swabs and bird brain samples were tested for flavivirus RNA by RT-PCR using newly designed generic primers. The species designation was confirmed by sequencing. WNV was detected in swab and brain samples, whereas one brain sample was positive for tick-borne encephalitis virus (TBEV). The WNV sequences clustered with lineages 1 and 2. These results confirm the circulation of WNV in birds in Slovakia and emphasize the risk of infection of humans and horses. PMID:27001305

  8. Tick-borne encephalitis virus subtypes emerged through rapid vector switches rather than gradual evolution

    PubMed Central

    Kovalev, Sergey Y; Mukhacheva, Tatyana A

    2014-01-01

    Tick-borne encephalitis is the most important human arthropod-borne virus disease in Europe and Russia, with an annual incidence of about 13 thousand people. Tick-borne encephalitis virus (TBEV) is distributed in the natural foci of forest and taiga zones of Eurasia, from the Pacific to the Atlantic coast. Currently, there are three mutually exclusive hypotheses about the origin and distribution of TBEV subtypes, although they are based on the same assumption of gradual evolution. Recently, we have described the structure of TBEV populations in terms of a clusteron approach, a clusteron being a structural unit of viral population [Kovalev and Mukhacheva (2013) Infect. Genet. Evol., 14, 22–28]. This approach allowed us to investigate questions of TBEV evolution in a new way and to propose a hypothesis of quantum evolution due to a vector switch. We also consider a possible mechanism for this switch occurring in interspecific hybrids of ticks. It is necessarily accompanied by a rapid accumulation of mutations in the virus genome, which is contrary to the generally accepted view of gradual evolution in assessing the ages of TBEV populations. The proposed hypothesis could explain and predict not only the formation of new subtypes, but also the emergence of new vector-borne viruses. PMID:25540692

  9. Tick-borne encephalitis virus subtypes emerged through rapid vector switches rather than gradual evolution.

    PubMed

    Kovalev, Sergey Y; Mukhacheva, Tatyana A

    2014-11-01

    Tick-borne encephalitis is the most important human arthropod-borne virus disease in Europe and Russia, with an annual incidence of about 13 thousand people. Tick-borne encephalitis virus (TBEV) is distributed in the natural foci of forest and taiga zones of Eurasia, from the Pacific to the Atlantic coast. Currently, there are three mutually exclusive hypotheses about the origin and distribution of TBEV subtypes, although they are based on the same assumption of gradual evolution. Recently, we have described the structure of TBEV populations in terms of a clusteron approach, a clusteron being a structural unit of viral population [Kovalev and Mukhacheva (2013) Infect. Genet. Evol., 14, 22-28]. This approach allowed us to investigate questions of TBEV evolution in a new way and to propose a hypothesis of quantum evolution due to a vector switch. We also consider a possible mechanism for this switch occurring in interspecific hybrids of ticks. It is necessarily accompanied by a rapid accumulation of mutations in the virus genome, which is contrary to the generally accepted view of gradual evolution in assessing the ages of TBEV populations. The proposed hypothesis could explain and predict not only the formation of new subtypes, but also the emergence of new vector-borne viruses. PMID:25540692

  10. Detection of North American eastern and western equine encephalitis viruses by nucleic acid amplification assays.

    PubMed

    Lambert, Amy J; Martin, Denise A; Lanciotti, Robert S

    2003-01-01

    We have developed nucleic acid sequence-based amplification (NASBA), standard reverse transcription PCR (RT-PCR), and TaqMan nucleic acid amplification assays for the rapid detection of North American eastern equine encephalitis (EEE) and western equine encephalitis (WEE) viral RNAs from samples collected in the field and clinical samples. The sensitivities of these assays have been compared to that of virus isolation. While all three types of nucleic acid amplification assays provide rapid detection of viral RNAs comparable to the isolation of viruses in Vero cells, the TaqMan assays for North American EEE and WEE viral RNAs are the most sensitive. We have shown these assays to be specific for North American EEE and WEE viral RNAs by testing geographically and temporally distinct strains of EEE and WEE viruses along with a battery of related and unrelated arthropodborne viruses. In addition, all three types of nucleic acid amplification assays have been used to detect North American EEE and WEE viral RNAs from mosquito and vertebrate tissue samples. The sensitivity, specificity, and rapidity of nucleic acid amplification demonstrate the usefulness of NASBA, standard RT-PCR, and TaqMan assays, in both research and diagnostic settings, to detect North American EEE and WEE viral RNAs. PMID:12517876

  11. Ecologic studies of Venezuelan encephalitis virus in Peru during 1970-1971.

    PubMed

    Scherer, W F; Madalengoitia, J; Flores, W; Acosta, M

    1975-04-01

    Venezuelan encephalitis (VE) virus has intermittently produced epidemics and equine epizootics on the dry Pacific coastal plain of Peru since at least the 1930's. However, evidence that the virus exists in the Amazon region of Peru to the east of the Andes mountains was not obtained until antibodies were found in human sera collected in 1965, and 10 strains of the virus were isolated in a forest near the city of Iquitos, Peru during February and March 1971. Eight strains came from mosquitoes and two from dead sentinel hamsters. Three hamsters exposed in forests near Iquitos developed VE virus antibodies suggesting that hamster-benign strains also exist there. Antibody tests of equine sera revealed no evidence that VE virus was actively cycling during the late 1950's or 1960's in southern coastal Peru, where equine epizootics had occurred in the 1930's and 1940's. In northern coastal Peru bordering Ecuador, antibodies were present in equine sera, presumably residual from the 1969 outbreak caused by subtype I virus, since neutralizing antibody titers were higher to subtype I virus than to subtypes III or IV. No VE virus was detected in this northern region during the dry season of 1970 by use of sentinel hamsters. The possibility is considered that VE epidemics and equine epizootics on the Pacific coast of Peru are caused by movements of virus in infected vertebrates traversing Andean passes or in infected vertebrates or mosquitoes carried in airplanes from the Amazon region. PMID:235838

  12. SiRNA Inhibits Replication of Langat Virus, a Member of the Tick-Borne Encephalitis Virus Complex in Organotypic Rat Brain Slices

    PubMed Central

    Maffioli, Carola; Grandgirard, Denis; Leib, Stephen L.; Engler, Olivier

    2012-01-01

    Tick-borne encephalitis virus is the causative agent of tick-borne encephalitis, a potentially fatal neurological infection. Tick-borne encephalitis virus belongs to the family of flaviviruses and is transmitted by infected ticks. Despite the availability of vaccines, approximately 2000–3000 cases of tick-borne encephalitis occur annually in Europe for which no curative therapy is available. The antiviral effects of RNA mediated interference by small interfering RNA (siRNA) was evaluated in cell culture and organotypic hippocampal cultures. Langat virus, a flavivirus highly related to Tick-borne encephalitis virus exhibits low pathogenicity for humans but retains neurovirulence for rodents. Langat virus was used for the establishment of an in vitro model of tick-borne encephalitis. We analyzed the efficacy of 19 siRNA sequences targeting different regions of the Langat genome to inhibit virus replication in the two in vitro systems. The most efficient suppression of virus replication was achieved by siRNA sequences targeting structural genes and the 3′ untranslated region. When siRNA was administered to HeLa cells before the infection with Langat virus, a 96.5% reduction of viral RNA and more than 98% reduction of infectious virus particles was observed on day 6 post infection, while treatment after infection decreased the viral replication by more than 98%. In organotypic hippocampal cultures the replication of Langat virus was reduced by 99.7% by siRNA sequence D3. Organotypic hippocampal cultures represent a suitable in vitro model to investigate neuronal infection mechanisms and treatment strategies in a preserved three-dimensional tissue architecture. Our results demonstrate that siRNA is an efficient approach to limit Langat virus replication in vitro. PMID:22984545

  13. Epidemiological trends and characteristics of Japanese encephalitis changed based on the vaccination program between 1960 and 2013 in Guangxi Zhuang Autonomous Region, southern China.

    PubMed

    Yang, Yan; Liang, Nengxiu; Tan, Yi; Xie, Zhichun

    2016-04-01

    Japanese encephalitis (JE) is one of the most severe kinds of viral encephalitis and is prevalent in Asia and the Western Pacific. In China, JE was first reported in the 1940s and became the main cause of viral encephalitis, including in the Guangxi Zhuang Autonomous Region. In 1951, JE was included in the Chinese mandatory disease reporting system. In the pre-vaccine era of the 1960s and 1970s, the incidence of JE continued to rise without any vaccine supply. Since JE vaccines became available in the late 1970s (MBD) and 1989 (LAV-SA-14-14-2), and as JE vaccine became freely available to patients beginning in 2008, the incidence of JE has declined significantly. Despite these gains, outbreaks continue to occur among children in rural and suburban areas. Strengthening vaccine delivery models and improving swine vaccine production are important in order to sustain continuous declines in the incidence of JE in Guangxi. PMID:26972041

  14. An Epizootic of Eastern Equine Encephalitis Virus, Maine, USA in 2009: Outbreak Description and Entomological Studies

    PubMed Central

    Lubelczyk, Charles; Mutebi, John-Paul; Robinson, Sara; Elias, Susan P.; Smith, Leticia B.; Juris, Sherrie A.; Foss, Kimberly; Lichtenwalner, Anne; Shively, Kirk J.; Hoenig, Donald E.; Webber, Lori; Sears, Stephen; Smith, Robert P.

    2013-01-01

    From July to September, 2009, an outbreak of eastern equine encephalitis virus (EEEv) occurred in five counties in Maine. The virus was isolated from 15 horses, 1 llama, and pheasants in three separate captive flocks. One wild turkey, screened before translocation, also showed exposure to the virus in January 2010. Two pools of Culiseta melanura (Coquillett) tested positive for EEEv during routine seasonal surveillance in York County in September, but none of the mosquitoes collected during rapid response surveys tested positive. There were more Cs. melanura in July, August, and September 2009 than in preceding (2006–08) and subsequent (2010–11) years. August and September Cs. melanura abundances were correlated with July rainfall, and abundance of all species combined was correlated with total rainfall for the meteorological summer. This outbreak represents a substantial expansion of the range of EEEv activity in northern New England. PMID:23208877

  15. Vertical and horizontal transmission of tilapia larvae encephalitis virus: the bad and the ugly.

    PubMed

    Sinyakov, Michael S; Belotsky, Sandro; Shlapobersky, Mark; Avtalion, Ramy R

    2011-02-01

    Impairment of innate immunity in tilapia larvae after vertical and horizontal infection with the newly characterized tilapia larvae encephalitis virus (TLEV) was accessed by evaluation of cell-mediated reactive oxygen species (ROS) production in affected fish with the use of horseradish peroxidase-amplified luminol-dependent chemiluminescence assay. The priming in-vivo infection with TLEV resulted in downregulation of ROS response in both vertically- and horizontally-infected fish; this suppression was further exacerbated by specific in-vitro booster infection with the same virus. Application of Ca ionophore and phorbol myristate acetate as alternative nonspecific boosters enabled restoration of ROS release in vertically-infected but not in horizontally-infected larvae. The results indicate severe TLEV-imposed phagocyte dysfunction in affected larvae. The difference in restoration potential of ROS production after vertical and horizontal virus transmission is interpreted in the frame of principal distinctions between the two modes. PMID:21131016

  16. Unusual Necrotizing Encephalitis in Raccoons and Skunks Concurrently Infected With Canine Distemper Virus and Sarcocystis sp.

    PubMed

    Kubiski, S V; Sisó, S; Church, M E; Cartoceti, A N; Barr, B; Pesavento, P A

    2016-05-01

    Canine distemper virus commonly infects free-ranging, terrestrial mesopredators throughout the United States. Due to the immunosuppressive effects of the virus, concurrent opportunistic infections are also common. Among these, secondary systemic protozoal infections have been described in a number of species. We report an unusual presentation of necrotizing encephalitis associated withSarcocystissp in four raccoons and one skunk concurrently infected with canine distemper virus. Lesions were characterized by variably sized necrotizing cavitations composed of abundant mineral admixed with inflammatory cells and protozoa.Sarcocystissp was confirmed via immunohistochemistry using a monoclonal antibody toSarcocystis neurona The pathologic changes are similar to lesions in human AIDS patients infected withToxoplasma gondii. PMID:26374278

  17. A vaccine candidate for eastern equine encephalitis virus based on IRES-mediated attenuation

    PubMed Central

    Pandya, Jyotsna; Gorchakov, Rodion; Wang, Eryu; Leal, Grace; Weaver, Scott C.

    2012-01-01

    To develop an effective vaccine against eastern equine encephalitis (EEE), we engineered a recombinant EEE virus (EEEV) that was attenuated and capable of replicating only in vertebrate cells, an important safety feature for live vaccines against mosquito-borne viruses. The subgenomic promoter was inactivated with 13 synonymous mutations and expression of the EEEV structural proteins was placed under the control of an internal ribosomal entry site (IRES) derived from encephalomyocarditis virus (EMCV). We tested this vaccine candidate for virulence, viremia and efficacy in the murine model. A single subcutaneous immunization with 104 infectious units protected 100% of mice against intraperitoneal challenge with a highly virulent North American EEEV strain. None of the mice developed any signs of disease or viremia after immunization or following challenge. Our findings suggest that the IRES-based attenuation approach can be used to develop a safe and effective vaccine against EEE and other alphaviral diseases. PMID:22222869

  18. The impact of eastern equine encephalitis virus on efforts to recover the endangered whooping crane

    USGS Publications Warehouse

    Carpenter, J.W.; Clark, G.G.; Watts, D.M.

    1989-01-01

    The whooping crane (Grus americana), although never abundant in North America, became endangered primarily because of habitat modification and destruction. To help recovery, a captive propagation and reintroduction program was initiated at the Patuxent Wildlife Research Center (PWRC) in 1966. However, in 1984, 7 of 39 whooping cranes at PWRC died from infection by eastern equine encephalitis (EEE) virus, an arbovirus that infects a wide variety of indigenous bird species, although mortality is generally restricted to introduced birds. Following identification of the aetiological agent, surveillance and control measures were implemented, including serological monitoring of both wild and captive birds for EEE viral antibody and assay of locally-trapped mosquitoes for virus. In addition, an inactivated EEE virus vaccine developed for use in humans was evaluated in captive whooping cranes. Results so far suggest that the vaccine will afford protection to susceptible birds.

  19. A Security Guard With West Nile Virus Encephalitis.

    PubMed

    Smith, Letha

    2016-01-01

    A 57-year-old male working as a security supervisor in an office building was seen for return to work by the on-site occupational health nurse. He was observed to have slow gait as he entered the clinic waiting area, was pale, diaphoretic, and slow in responding to questions. His return to work note stated he was recovering from West Nile Virus (WNV). Implications for return to work are presented. PMID:26245464

  20. Venezuelan equine encephalitis virus infection causes modulation of inflammatory and immune response genes in mouse brain

    PubMed Central

    Sharma, Anuj; Bhattacharya, Bhaskar; Puri, Raj K; Maheshwari, Radha K

    2008-01-01

    Background Neurovirulent Venezuelan equine encephalitis virus (VEEV) causes lethal encephalitis in equines and is transmitted to humans by mosquitoes. VEEV is highly infectious when transmitted by aerosol and has been developed as a bio-warfare agent, making it an important pathogen to study from a military and civilian standpoint. Molecular mechanisms of VEE pathogenesis are poorly understood. To study these, the gene expression profile of VEEV infected mouse brains was investigated. Changes in gene expression were correlated with histological changes in the brain. In addition, a molecular framework of changes in gene expression associated with progression of the disease was studied. Results Our results demonstrate that genes related to important immune pathways such as antigen presentation, inflammation, apoptosis and response to virus (Cxcl10, CxCl11, Ccl5, Ifr7, Ifi27 Oas1b, Fcerg1,Mif, Clusterin and MHC class II) were upregulated as a result of virus infection. The number of over-expressed genes (>1.5-fold level) increased as the disease progressed (from 197, 296, 400, to 1086 at 24, 48, 72 and 96 hours post infection, respectively). Conclusion Identification of differentially expressed genes in brain will help in the understanding of VEEV-induced pathogenesis and selection of biomarkers for diagnosis and targeted therapy of VEEV-induced neurodegeneration. PMID:18558011

  1. Morphological changes in human neural cells following tick-borne encephalitis virus infection.

    PubMed

    Růzek, Daniel; Vancová, Marie; Tesarová, Martina; Ahantarig, Arunee; Kopecký, Jan; Grubhoffer, Libor

    2009-07-01

    Tick-borne encephalitis (TBE) is one of the leading and most dangerous human viral neuroinfections in Europe and north-eastern Asia. The clinical manifestations include asymptomatic infections, fevers and debilitating encephalitis that might progress into chronic disease or fatal infection. To understand TBE pathology further in host nervous systems, three human neural cell lines, neuroblastoma, medulloblastoma and glioblastoma, were infected with TBE virus (TBEV). The susceptibility and virus-mediated cytopathic effect, including ultrastructural and apoptotic changes of the cells, were examined. All the neural cell lines tested were susceptible to TBEV infection. Interestingly, the neural cells produced about 100- to 10,000-fold higher virus titres than the conventional cell lines of extraneural origin, indicating the highly susceptible nature of neural cells to TBEV infection. The infection of medulloblastoma and glioblastoma cells was associated with a number of major morphological changes, including proliferation of membranes of the rough endoplasmic reticulum and extensive rearrangement of cytoskeletal structures. The TBEV-infected cells exhibited either necrotic or apoptotic morphological features. We observed ultrastructural apoptotic signs (condensation, margination and fragmentation of chromatin) and other alterations, such as vacuolation of the cytoplasm, dilatation of the endoplasmic reticulum cisternae and shrinkage of cells, accompanied by a high density of the cytoplasm. On the other hand, infected neuroblastoma cells did not exhibit proliferation of membranous structures. The virions were present in both the endoplasmic reticulum and the cytoplasm. Cells were dying preferentially by necrotic mechanisms rather than apoptosis. The neuropathological significance of these observations is discussed. PMID:19264624

  2. Second Generation Inactivated Eastern Equine Encephalitis Virus Vaccine Candidates Protect Mice against a Lethal Aerosol Challenge

    PubMed Central

    Honnold, Shelley P.; Bakken, Russell R.; Fisher, Diana; Lind, Cathleen M.; Cohen, Jeffrey W.; Eccleston, Lori T.; Spurgers, Kevin B.; Maheshwari, Radha K.; Glass, Pamela J.

    2014-01-01

    Currently, there are no FDA-licensed vaccines or therapeutics for eastern equine encephalitis virus (EEEV) for human use. We recently developed several methods to inactivate CVEV1219, a chimeric live-attenuated eastern equine encephalitis virus (EEEV). Dosage and schedule studies were conducted to evaluate the immunogenicity and protective efficacy of three potential second-generation inactivated EEEV (iEEEV) vaccine candidates in mice: formalin-inactivated CVEV1219 (fCVEV1219), INA-inactivated CVEV1219 (iCVEV1219) and gamma-irradiated CVEV1219 (gCVEV1219). Both fCVEV1219 and gCVEV1219 provided partial to complete protection against an aerosol challenge when administered by different routes and schedules at various doses, while iCVEV1219 was unable to provide substantial protection against an aerosol challenge by any route, dose, or schedule tested. When evaluating antibody responses, neutralizing antibody, not virus specific IgG or IgA, was the best correlate of protection. The results of these studies suggest that both fCVEV1219 and gCVEV1219 should be evaluated further and considered for advancement as potential second-generation inactivated vaccine candidates for EEEV. PMID:25116127

  3. Parasitic Cowbirds have increased immunity to West Nile and other mosquitoborne encephalitis viruses

    USGS Publications Warehouse

    Reisen, W.K.; Hahn, D.C.

    2006-01-01

    The rapid geographic spread of West Nile Virus [WNV, Flaviviridae, Flavivirus] across the United States has stimulated interest in comparative host infection studies of avian species to delineate competent reservoir hosts critical for viral amplification. Striking taxonomic differences in avian susceptibility have been noted, offering the opportunity to strategically select species on the basis of life history traits to examine aspects of pathogen virulence or host immunity. We hypothesized that avian brood parasites would show increased resistance to pathogens compared to related taxa, because they have been exposed in their evolutionary history to a wide array of infectious organisms from their different parenting species. The Brown-headed Cowbird (Molothrus ater) is a generalist brood parasite that parasitizes 200+ North American species. Elevated exposure to other species? parasites may have created an unusual degree of pathogen resistance. We compared the relative susceptibility of adult cowbirds to three closely-related non-parasitic species, Red-winged blackbirds, Tricolored blackbirds and Brewer?s blackbirds, to invading NY99 strain of WNV that is highly virulent for many passeriform birds. Previously we had experimentally infected these species with two North American mosquitoborne encephalitis viruses, western equine encephalomyelitis virus [WEEV, Togaviridae, Alphavirus] and St. Louis encephalitis virus [SLEV, Flaviviridae, Flavivirus]. Our results showed that cowbirds exhibited significantly lower viremia responses against all three viruses as well as after co-infection with both WEEV and WNV than did the three related, non-parasitic species. These data supported our hypothesis and indicated that cowbirds were more resistant to infection to both native and introduced viruses.

  4. Comparative Sequence Analyses of La Crosse Virus Strain Isolated from Patient with Fatal Encephalitis, Tennessee, USA

    PubMed Central

    Fryxell, Rebecca Trout; Freyman, Kimberly; Ulloa, Armando; Velez, Jason O.; Paulsen, Dave; Lanciotti, Robert S.; Moncayo, Abelardo

    2015-01-01

    We characterized a La Crosse virus (LACV) isolate from the brain of a child who died of encephalitis-associated complications in eastern Tennessee, USA, during summer 2012. We compared the isolate with LACV sequences from mosquitoes collected near the child’s home just after his postmortem diagnosis. In addition, we conducted phylogenetic analyses of these and other sequences derived from LACV strains representing varied temporal, geographic, and ecologic origins. Consistent with historical findings, results of these analyses indicate that a limited range of LACV lineage I genotypes is associated with severe clinical outcomes. PMID:25898269

  5. Focal encephalitis following varicella-zoster virus reactivation without rash in a healthy immunized young adult.

    PubMed

    Halling, Geoffrey; Giannini, Caterina; Britton, Jeffrey W; Lee, Ricky W; Watson, Robert E; Terrell, Christine L; Parney, Ian F; Buckingham, Erin M; Carpenter, John E; Grose, Charles

    2014-09-01

    Herein we describe an episode of focal varicella-zoster virus (VZV) encephalitis in a healthy young man with neither rash nor radicular pain. The symptoms began with headaches and seizures, after which magnetic resonance imaging detected a single hyperintense lesion in the left temporal lobe. Because of the provisional diagnosis of a brain tumor, the lesion was excised and submitted for pathological examination. No tumor was found. But the tissue immunostained positively for VZV antigens, and wild-type VZV sequences were detected. In short, this case represents VZV reactivation, most likely in the trigeminal ganglion, in the absence of clinical herpes zoster. PMID:24604820

  6. Siberian subtype tick-borne encephalitis virus in Ixodes ricinus in a newly emerged focus, Finland.

    PubMed

    Jääskeläinen, Anu; Tonteri, Elina; Pieninkeroinen, Ilkka; Sironen, Tarja; Voutilainen, Liina; Kuusi, Markku; Vaheri, Antti; Vapalahti, Olli

    2016-02-01

    The first tick-borne encephalitis (TBE) cases in Kotka, Finland appeared in 2010. Altogether ten human cases have been diagnosed by 2014. Four had long-lasting sequelae. We collected 195 Ixodes ricinus ticks, nine rodents, and eleven shrews from the archipelago of Kotka in 2011. Three Siberian subtype TBE virus (TBEV) strains were isolated from the ticks and three mammals were positive for TBEV antibodies. The archipelago of Kotka is a newly emerged TBE focus of Siberian subtype TBEV circulating notably in I. ricinus. The patients had on average longer hospitalization than reported for the European subtype infection. PMID:26548609

  7. Construction and characterization of chimeric tick-borne encephalitis/dengue type 4 viruses.

    PubMed Central

    Pletnev, A G; Bray, M; Huggins, J; Lai, C J

    1992-01-01

    Dengue type 4 virus (DEN4) cDNA was used as a vector to express genes of the distantly related tick-borne encephalitis virus (TBEV). Full-length chimeric TBEV/DEN4 cDNAs were constructed by substituting TBEV genes coding for proteins such as capsid (C); pre-membrane, which is the precursor of membrane (M); envelope (E); or nonstructural protein NS1 for the corresponding DEN4 sequences. RNA transcripts prepared from cDNAs were used to transfect permissive simian cells. Two viable chimeric viruses that contained TBEV CME or ME genes were recovered. Compared with DEN4, chimeric TBE(ME)/DEN4 virus [designated vTBE(ME)/DEN4] produced larger plaques and grew to higher titer in simian cells. In contrast, vTBE(ME)/DEN4 produced smaller plaques on mosquito cells and grew to lower titer than DEN4. Analysis of viral RNA and proteins produced in vTBE(ME)/DEN4- and DEN4-infected mosquito or simian cells revealed that the chimera was restricted in its ability to enter and replicate in mosquito cells. In contrast, vTBE(ME)/DEN4 entered simian cells efficiently and its RNA was replicated more rapidly in these cells than was parental DEN4 RNA. Following intracerebral inoculation, vTBE(ME)/DEN4 caused fatal encephalitis in both suckling and adult mice, while nearly all mice inoculated by the same route with DEN4 did not develop disease. Unlike wild-type TBEV, vTBE(ME)/DEN4 did not cause encephalitis when adult mice were inoculated by a peripheral route. Adult mice previously inoculated with the chimera by a peripheral route were completely resistant to subsequent intraperitoneal challenge with 10(3) times the median lethal dose of TBEV, whereas mice previously inoculated with DEN4 were not protected. These findings indicate that (i) the TBEV M and E genes of the chimeric virus are major protective antigens and induce resistance to lethal TBEV challenge and (ii) other regions of the TBEV genome are essential for the ability of this virus to spread from a peripheral site to the brain

  8. Regional Variation in Pig Farmer Awareness and Actions Regarding Japanese Encephalitis in Nepal: Implications for Public Health Education

    PubMed Central

    Dhakal, Santosh; Joshi, Durga Datt; Ale, Anita; Sharma, Minu; Dahal, Meena; Shah, Yogendra; Pant, Dhan Kumar; Stephen, Craig

    2014-01-01

    Japanese encephalitis (JE) is a mosquito-borne zoonotic disease that has pigs as the major amplifying hosts. It is the most important cause of viral encephalitis in people in Nepal and is spreading in its geographic distribution in that country. Pig farming is increasing in Nepal due to reducing cultural biases against pigs and government programs to support pig farming for poverty alleviation. Major strategies for JE prevention and control include education, vector control, and immunization of people and pigs. This study used a survey of 400 pig farmers in 4 areas of Nepal with different JE and pig farming histories to explore regional variations in farmer awareness and actions towards JE, the association of awareness and actions with farm and farmer variables, and the implications of these associations for public health education. Exposure to JE risk factors was common across pig farms and pig farming districts but there were significant district level differences in knowledge and practices related to on-farm JE risk reduction. Social factors such as literacy, gender, and cultural practices were associated with farmer attitudes, knowledge and practices for JE control. JE vaccine uptake was almost non-existent and mosquito control steps were inconsistently applied across all 4 districts. Income was not a determining factor of the differences, but all farmers were very poor. The low uptake of vaccine and lack of infrastructure or financial capacity to house pigs indoors or away from people suggest that farmer personal protection should be a priority target for education in Nepal. This study re-enforces the need to attack root causes of people’s personal disease prevention behaviours and take into account local variation in needs and capacities when designing health or agriculture education programs. PMID:24416402

  9. Regional variation in pig farmer awareness and actions regarding Japanese encephalitis in Nepal: implications for public health education.

    PubMed

    Dhakal, Santosh; Joshi, Durga Datt; Ale, Anita; Sharma, Minu; Dahal, Meena; Shah, Yogendra; Pant, Dhan Kumar; Stephen, Craig

    2014-01-01

    Japanese encephalitis (JE) is a mosquito-borne zoonotic disease that has pigs as the major amplifying hosts. It is the most important cause of viral encephalitis in people in Nepal and is spreading in its geographic distribution in that country. Pig farming is increasing in Nepal due to reducing cultural biases against pigs and government programs to support pig farming for poverty alleviation. Major strategies for JE prevention and control include education, vector control, and immunization of people and pigs. This study used a survey of 400 pig farmers in 4 areas of Nepal with different JE and pig farming histories to explore regional variations in farmer awareness and actions towards JE, the association of awareness and actions with farm and farmer variables, and the implications of these associations for public health education. Exposure to JE risk factors was common across pig farms and pig farming districts but there were significant district level differences in knowledge and practices related to on-farm JE risk reduction. Social factors such as literacy, gender, and cultural practices were associated with farmer attitudes, knowledge and practices for JE control. JE vaccine uptake was almost non-existent and mosquito control steps were inconsistently applied across all 4 districts. Income was not a determining factor of the differences, but all farmers were very poor. The low uptake of vaccine and lack of infrastructure or financial capacity to house pigs indoors or away from people suggest that farmer personal protection should be a priority target for education in Nepal. This study re-enforces the need to attack root causes of people's personal disease prevention behaviours and take into account local variation in needs and capacities when designing health or agriculture education programs. PMID:24416402

  10. Molecular determinants of mouse neurovirulence and mosquito infection for Western equine encephalitis virus.

    PubMed

    Mossel, Eric C; Ledermann, Jeremy P; Phillips, Aaron T; Borland, Erin M; Powers, Ann M; Olson, Ken E

    2013-01-01

    Western equine encephalitis virus (WEEV) is a naturally occurring recombinant virus derived from ancestral Sindbis and Eastern equine encephalitis viruses. We previously showed that infection by WEEV isolates McMillan (McM) and IMP-181 (IMP) results in high (∼90-100%) and low (0%) mortality, respectively, in outbred CD-1 mice when virus is delivered by either subcutaneous or aerosol routes. However, relatively little is known about specific virulence determinants of WEEV. We previously observed that IMP infected Culex tarsalis mosquitoes at a high rate (app. 80%) following ingestion of an infected bloodmeal but these mosquitoes were infected by McM at a much lower rate (10%). To understand the viral role in these phenotypic differences, we characterized the pathogenic phenotypes of McM/IMP chimeras. Chimeras encoding the E2 of McM on an IMP backbone (or the reciprocal) had the most significant effect on infection phenotypes in mice or mosquitoes. Furthermore, exchanging the arginine, present on IMP E2 glycoprotein at position 214, for the glutamine present at the same position on McM, ablated mouse mortality. Curiously, the reciprocal exchange did not confer mouse virulence to the IMP virus. Mosquito infectivity was also determined and significantly, one of the important loci was the same as the mouse virulence determinant identified above. Replacing either IMP E2 amino acid 181 or 214 with the corresponding McM amino acid lowered mosquito infection rates to McM-like levels. As with the mouse neurovirulence, reciprocal exchange of amino acids did not confer mosquito infectivity. The identification of WEEV E2 amino acid 214 as necessary for both IMP mosquito infectivity and McM mouse virulence indicates that they are mutually exclusive phenotypes and suggests an explanation for the lack of human or equine WEE cases even in the presence of active transmission. PMID:23544138

  11. Structure of a Venezuelan equine encephalitis virus assembly intermediate isolated from infected cells

    SciTech Connect

    Lamb, Kristen; Lokesh, G.L.; Sherman, Michael; Watowich, Stanley

    2010-10-25

    Venezuelan equine encephalitis virus (VEEV) is a prototypical enveloped ssRNA virus of the family Togaviridae. To better understand alphavirus assembly, we analyzed newly formed nucleocapsid particles (termed pre-viral nucleocapsids) isolated from infected cells. These particles were intermediates along the virus assembly pathway, and ultimately bind membrane-associated viral glycoproteins to bud as mature infectious virus. Purified pre-viral nucleocapsids were spherical with a unimodal diameter distribution. The structure of one class of pre-viral nucleocapsids was determined with single particle reconstruction of cryo-electron microscopy images. These studies showed that pre-viral nucleocapsids assembled into an icosahedral structure with a capsid stoichiometry similar to the mature nucleocapsid. However, the individual capsomers were organized significantly differently within the pre-viral and mature nucleocapsids. The pre-viral nucleocapsid structure implies that nucleocapsids are highly plastic and undergo glycoprotein and/or lipid-driven rearrangements during virus self-assembly. This mechanism of self-assembly may be general for other enveloped viruses.

  12. Virion envelope glycoproteins as epidermiological markers of Venezuelan encephalitis virus isolates.

    PubMed Central

    Wiebe, M E; Scherer, W F

    1980-01-01

    Virion polypeptide compositions of 26 isolates of Venezuelan encephalitis virus were analyzed by a reproducible and comparative technique of discontinuous sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis. Although the molecular weight of the core polypeptide for each isolate was 36,000, numbers and molecular weights of envelope glycoproteins were heterogeneous. Isolates associated with human, but not equine, disease usually had two glycoproteins of 50,000 to 51,000 and 51,000 to 55,000 molecular weight, whereas isolates associated with both human and equine disease usually had an additional, third polypeptide band of either 45,000 to 46,000 or 56,000 to 58,000 molecular weight. The former isolates were in hemagglutination inhibition subtypes I-D, I-E, III, or IV, and the latter were in subtypes I-A, I-B, I-C, or II. Thus virion envelope glycoproteins should be useful markers of Venezuelan encephalitis virus isolates in epidemiological investigations. PMID:7372798

  13. Field Investigations of Winter Transmission of Eastern Equine Encephalitis Virus in Florida

    PubMed Central

    Bingham, Andrea M.; Burkett-Cadena, Nathan D.; Hassan, Hassan K.; McClure, Christopher J. W.; Unnasch, Thomas R.

    2014-01-01

    Studies investigating winter transmission of Eastern equine encephalitis virus (EEEV) were conducted in Hillsborough County, Florida. The virus was detected in Culiseta melanura and Anopheles quadrimaculatus in February 2012 and 2013, respectively. During the winter months, herons were the most important avian hosts for all mosquito species encountered. In collections carried out in the summer of 2011, blood meals taken from herons were still common, but less frequently encountered than in winter, with an increased frequency of mammalian- and reptile-derived meals observed in the summer. Four wading bird species (Black-crowned Night Heron [Nycticorax nycticorax], Yellow-crowned Night Heron [Nyctanassa violacea], Anhinga [Anhinga anhinga], and Great Blue Heron [Ardea herodias]) were most frequently fed upon by Cs. melanura and Culex erraticus, suggesting that these species may participate in maintaining EEEV during the winter in Florida. PMID:25070997

  14. Field investigations of winter transmission of eastern equine encephalitis virus in Florida.

    PubMed

    Bingham, Andrea M; Burkett-Cadena, Nathan D; Hassan, Hassan K; McClure, Christopher J W; Unnasch, Thomas R

    2014-10-01

    Studies investigating winter transmission of Eastern equine encephalitis virus (EEEV) were conducted in Hillsborough County, Florida. The virus was detected in Culiseta melanura and Anopheles quadrimaculatus in February 2012 and 2013, respectively. During the winter months, herons were the most important avian hosts for all mosquito species encountered. In collections carried out in the summer of 2011, blood meals taken from herons were still common, but less frequently encountered than in winter, with an increased frequency of mammalian- and reptile-derived meals observed in the summer. Four wading bird species (Black-crowned Night Heron [Nycticorax nycticorax], Yellow-crowned Night Heron [Nyctanassa violacea], Anhinga [Anhinga anhinga], and Great Blue Heron [Ardea herodias]) were most frequently fed upon by Cs. melanura and Culex erraticus, suggesting that these species may participate in maintaining EEEV during the winter in Florida. PMID:25070997

  15. Structural and biophysical analysis of sequence insertions in the Venezuelan Equine Encephalitis Virus macro domain.

    PubMed

    Guillén, Jaime; Lichière, Julie; Rabah, Nadia; Beitzel, Brett F; Canard, Bruno; Coutard, Bruno

    2015-04-01

    Random transposon insertions in viral genomes can be used to reveal genomic regions important for virus replication. We used these genomic data to evaluate at the protein level the effect of such insertions on the Venezuelan Equine Encephalitis Virus nsP3 macro domain. The structural analysis showed that transposon insertions occur mainly in loops connecting the secondary structure elements. Some of the insertions leading to a temperature sensitive viral phenotype (ts) are close to the cleavage site between nsP2 and nsP3 or the ADP-ribose binding site, two important functions of the macro domain. Using four mutants mimicking the transposon insertions, we confirmed that these insertions can affect the macro domain properties without disrupting the overall structure of the protein. PMID:25725151

  16. Natural Enzootic Vectors of Venezuelan equine encephalitis virus in the Magdalena Valley, Colombia

    PubMed Central

    Ferro, Cristina; Boshell, Jorge; Moncayo, Abelardo C.; Gonzalez, Marta; Ahumada, Marta L.; Kang, Wenli

    2003-01-01

    To characterize the transmission cycle of enzootic Venezuelan equine encephalitis virus (VEEV) strains believed to represent an epizootic progenitor, we identified natural vectors in a sylvatic focus in the middle Magdalena Valley of Colombia. Hamster-baited traps were placed into an active forest focus, and mosquitoes collected from each trap in which a hamster became infected were sorted by species and assayed for virus. In 18 cases, a single, initial, high-titered mosquito pool representing the vector species was identified. These vectors included Culex (Melanoconion) vomerifer (11 transmission events), Cx. (Mel.) pedroi (5 transmissions) and Cx. (Mel.) adamesi (2 transmissions). These results extend the number of proven enzootic VEEV vectors to 7, all of which are members of the Spissipes section of the subgenus Melanoconion. Our findings contrast with previous studies, which have indicated that a single species usually serves as the principal enzootic VEEV vector at a given location. PMID:12533281

  17. Small molecule inhibitors of Ago2 decrease Venezuelan equine encephalitis virus replication.

    PubMed

    Madsen, Cathaleen; Hooper, Idris; Lundberg, Lindsay; Shafagati, Nazly; Johnson, Alexandra; Senina, Svetlana; de la Fuente, Cynthia; Hoover, Lisa I; Fredricksen, Brenda L; Dinman, Jonathan; Jacobs, Jonathan L; Kehn-Hall, Kylene

    2014-12-01

    Venezuelan equine encephalitis virus (VEEV) is classified as a Category B Select Agent and potential bioterror weapon for its severe disease course in humans and equines and its potential for aerosol transmission. There are no current FDA licensed vaccines or specific therapies against VEEV, making identification of potential therapeutic targets a priority. With this aim, our research focuses on the interactions of VEEV with host microRNA (miRNA) machinery. miRNAs are small non-coding RNAs that act as master regulators of gene expression by downregulating or degrading messenger RNA, thus suppressing production of the resultant proteins. Recent publications implicate miRNA interactions in the pathogenesis of various viral diseases. To test the importance of miRNA processing for VEEV replication, cells deficient in Ago2, an important component of the RNA-induced silencing complex (RISC), and cells treated with known Ago2 inhibitors, notably acriflavine (ACF), were utilized. Both conditions caused decreased viral replication and capsid expression. ACF treatment promoted increased survival of neuronal cells over a non-treated, infected control and reduced viral titers of fully virulent VEEV as well as Eastern and Western Equine Encephalitis Viruses and West Nile Virus, but not Vesicular Stomatitis Virus. ACF treatment of VEEV TC-83 infected mice resulted in increased in vivo survival, but did not affect survival or viral loads when mice were challenged with fully virulent VEEV TrD. These results suggest that inhibition of Ago2 results in decreased replication of encephalitic alphaviruses in vitro and this pathway may be an avenue to explore for future therapeutic development. PMID:25448087

  18. Phenotypic alteration of blood and milk leukocytes in goats infected with caprine arthritis-encephalitis virus (CAEV)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Caprine arthritis-encephalitis virus (CAEV) causes a persistent and slow progressive infection in goats, characterized by chronic proliferative sinovitis, arthritis and, less frequently, pneumonia. Infected goats could also be affected by interstitial mastitis. The aim of this study was to evaluate ...

  19. Chimeric tick-borne encephalitis and dengue type 4 viruses: effects of mutations on neurovirulence in mice.

    PubMed Central

    Pletnev, A G; Bray, M; Lai, C J

    1993-01-01

    Two new chimeric flaviviruses were constructed from full-length cDNAs that contained tick-borne encephalitis virus (TBEV) CME or ME structural protein genes and the remaining genes derived from dengue type 4 virus (DEN4). Studies involving mice inoculated intracerebrally with the ME chimeric virus indicated that it retained the neurovirulence of its TBEV parent from which its pre-M and E genes were derived. However, unlike parental TBEV, the chimeric virus did not produce encephalitis when mice were inoculated peripherally, indicating a loss of neuroinvasiveness. In the present study, the ME chimeric virus (vME) was subjected to mutational analysis in an attempt to reduce or ablate neurovirulence measured by direct inoculation of virus into the brain. We identified three distinct mutations that were each associated independently with a significant reduction of mouse neurovirulence of vME. These mutations ablated (i) the TBEV pre-M cleavage site, (ii) the TBEV E glycosylation site, or (iii) the first DEN4 NS1 glycosylation site. In contrast, ablation of the second DEN4 NS1 glycosylation site or the TBE pre-M glycosylation site or amino acid substitution at two positions in the TBEV E protein increased neurovirulence. The only conserved feature of the three attenuated mutants was restriction of virus yield in both simian and mosquito cells. Following parenteral inoculation, these attenuated mutants induced complete resistance in mice to fatal encephalitis caused by the highly neurovirulent vME. Images PMID:8331735

  20. Green synthesis and characterization of silver nanoparticles fabricated using Anisomeles indica: Mosquitocidal potential against malaria, dengue and Japanese encephalitis vectors.

    PubMed

    Govindarajan, Marimuthu; Rajeswary, Mohan; Veerakumar, Kaliyan; Muthukumaran, Udaiyan; Hoti, S L; Benelli, Giovanni

    2016-02-01

    Mosquitoes (Diptera: Culicidae) represent a key threat for millions of people worldwide, since they act as vectors for devastating parasites and pathogens. In this scenario, eco-friendly control tools against mosquito vectors are a priority. Green synthesis of silver nanoparticles (AgNP) using a cheap, aqueous leaf extract of Anisomeles indica by reduction of Ag(+) ions from silver nitrate solution has been investigated. Bio-reduced AgNP were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX) and X-ray diffraction analysis (XRD). The acute toxicity of A. indica leaf extract and biosynthesized AgNP was evaluated against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. Both the A. indica leaf extract and AgNP showed dose dependent larvicidal effect against all tested mosquito species. Compared to the leaf aqueous extract, biosynthesized AgNP showed higher toxicity against An. subpictus, Ae. albopictus, and Cx. tritaeniorhynchus with LC50 values of 31.56, 35.21 and 38.08 μg/mL, respectively. Overall, this study firstly shed light on the mosquitocidal potential of A. indica, a potential bioresource for rapid, cheap and effective AgNP synthesis. PMID:26708933

  1. Japanese Encephalitis Risk and Contextual Risk Factors in Southwest China: A Bayesian Hierarchical Spatial and Spatiotemporal Analysis

    PubMed Central

    Zhao, Xing; Cao, Mingqin; Feng, Hai-Huan; Fan, Heng; Chen, Fei; Feng, Zijian; Li, Xiaosong; Zhou, Xiao-Hua

    2014-01-01

    It is valuable to study the spatiotemporal pattern of Japanese encephalitis (JE) and its association with the contextual risk factors in southwest China, which is the most endemic area in China. Using data from 2004 to 2009, we applied GISmapping and spatial autocorrelation analysis to analyze reported incidence data of JE in 438 counties in southwest China, finding that JE cases were not randomly distributed, and a Bayesian hierarchical spatiotemporal model identified the east part of southwest China as a high risk area. Meanwhile, the Bayesian hierarchical spatial model in 2006 demonstrated a statistically significant association between JE and the agricultural and climatic variables, including the proportion of rural population, the pig-to-human ratio, the monthly precipitation and the monthly mean minimum and maximum temperatures. Particular emphasis was placed on the time-lagged effect for climatic factors. The regression method and the Spearman correlation analysis both identified a two-month lag for the precipitation, while the regression method found a one-month lag for temperature. The results show that the high risk area in the east part of southwest China may be connected to the agricultural and climatic factors. The routine surveillance and the allocation of health resources should be given more attention in this area. Moreover, the meteorological variables might be considered as possible predictors of JE in southwest China. PMID:24739769

  2. A Preliminary Study to Forecast Japanese Encephalitis Vector Abundance in Paddy Growing Area, with the Aid of Radar Satellite Images.

    PubMed

    Raju, K Hari Kishan; Sabesan, Shanmugavelu; Rajavel, Aladu Ramakrishnan; Subramanian, Swaminathan; Natarajan, Ramalingam; Thenmozhi, Velayutham; Tyagi, Brij Kishore; Jambulingam, Purushothaman

    2016-02-01

    Vector mosquitoes of Japanese encephalitis (JE) breed mostly in rice fields, and human cases occur scattered over extended rural rice-growing areas. From this, one may surmise an ecological connection with the irrigation facilities and paddy cultivation. Furthermore, it has been hypothesized that a particular stage of paddy growth is a premonitory sign that can lead to a markedly increased population of the vector mosquitoes. The present study aimed to forecast the vector abundance by monitoring the paddy growth using remote sensing and geographical information systems. The abundance of the JE vector Culex tritaeniorhynchus peaked when the paddy crop was at its heading stage and dipped when the crop reached the maturing stage. A significant positive correlation was observed between paddy growth and adult density (r = 0.73, p < 0.008). The sigma naught values (σ0) derived from satellite images of paddy fields ranged from -18.3 (during transplantation stage) to approximately -10 (during the noncultivation period). A significant positive correlation was observed between σ0 and paddy growth stages (r = 0.87, p < 0.05) and adult vector density (r = 0.74, p = 0.04). The σ0 value observed during the vegetative and flowering stages of paddy growth ranged from -17.6 to -17.16, at which period the vector density started building up. This could be the spectral signature that denotes the "risk," following which a high vector abundance is expected during heading stage of the paddy. PMID:26824289

  3. Use of an inactivated eastern equine encephalitis virus vaccine in cranes

    USGS Publications Warehouse

    Carpenter, J.W.; Dein, F.J.; Clark, G.G.; Watts, D.M.; Crabbs, C.L.

    1986-01-01

    An unprecedented outbreak of fatal eastern equine encephalitis (EEE) virus occurred during the late summer and fall of 1984 in endangered whooping cranes (Grus americana) at the Patuxent Wildlife Research Center, Laurel, Maryland. As part of efforts to prevent future epizootics of EEE. studies were conducted to evaluate the antibody response of cranes following vaccination with a formalin-inactivated EEE virus vaccine. Viral specific neutralizing antibody was elicited in sandhill cranes (Grus canadensis) and whooping cranes following 1M inoculation with the vaccine. Among the 1M-inoculated cranes, peak antibody titers of 1:80 on days 30 to 60 had waned to undetectable levels by days 90 to 120. Although the initial titers were not increased by the first booster dose, the duration of the antibody was extended considerably. Whooping cranes, receiving vaccine 6 months after their first vaccination, developed titers of 1:80 to 1:320 by day 30. At 45 days after the final vaccination, these titers had dropped to 1:10 to 1:160. Cranes with preexisting EEE virus antibody, apparently reflecting natural infection, exhibited an anamnestic response indicated by a rapid increase and sustained high antibody titer. Even though EEE virus vaccine induced neutralizing antibody and produced no adverse side effects, further studies will be required to assess the significance of this response as a strategy for protecting whooping cranes against natural EEE virus infection. The loss of captive whooping cranes to the EEE virus presented a previously unrecognized risk and obstacle to recovery of this species. Not only was, there a setback in the captive breeding and reintroduction program for the whooping crane, but, because of the susceptibility of the species to the EEE virus. establishment of additional crane populations may be more complicated than initially envisioned. However, through continued surveillance, serological monitoring, and vaccination activities, we are confident that

  4. Fatal human eosinophilic meningo-encephalitis caused by CNS co-infection with Halicephalobus gingivalis and West Nile virus.

    PubMed

    Anwar, M A; Gokozan, H N; Ball, M K; Otero, J; McGwire, B S

    2015-10-01

    The saprophytic nematode Halicephalobus is a rare cause of fatal human meningo-encephalitis, and West Nile virus is neurotropic flavivirus implicated in a variety of clinical neurologic syndromes. Here we report a case of rapidly progressive CNS encephalopathy and death. Serologic, immuno-histochemical, histopathologic and nucleic acid studies demonstrate the presence of active Halicephalobus and West Nile virus in the CNS tissue. This is the first reported case of co-infection with these neurotropic pathogens. PMID:26050925

  5. Prevalence of Intrathecal Acyclovir Resistant Virus in Herpes Simplex Encephalitis Patients.

    PubMed

    Mitterreiter, Johanna G; Titulaer, Maarten J; van Nierop, Gijsbert P; van Kampen, Jeroen J A; Aron, Georgina I; Osterhaus, Albert D M E; Verjans, Georges M G M; Ouwendijk, Werner J D

    2016-01-01

    Herpes simplex encephalitis (HSE) is a life-threatening complication of herpes simplex virus (HSV) infection. Acyclovir (ACV) is the antiviral treatment of choice, but may lead to emergence of ACV-resistant (ACVR) HSV due to mutations in the viral UL23 gene encoding for the ACV-targeted thymidine kinase (TK) protein. Here, we determined the prevalence of intrathecal ACVR-associated HSV TK mutations in HSE patients and compared TK genotypes of sequential HSV isolates in paired cerebrospinal fluid (CSF) and blister fluid of mucosal HSV lesions. Clinical samples were obtained from 12 HSE patients, encompassing 4 HSV type 1 (HSV-1) and 8 HSV-2 encephalitis patients. HSV DNA load was determined by real-time PCR and complete HSV TK gene sequences were obtained by nested PCR followed by Sanger sequencing. All HSV-1 HSE patients contained viral TK mutations encompassing 30 unique nucleotide and 13 distinct amino acid mutations. By contrast, a total of 5 unique nucleotide and 4 distinct amino acid changes were detected in 7 of 8 HSV-2 patients. Detected mutations were identified as natural polymorphisms located in non-conserved HSV TK gene regions. ACV therapy did not induce the emergence of ACVR-associated HSV TK mutations in consecutive CSF and mucocutaneous samples of 5 individual patients. Phenotypic susceptibility analysis of these mucocutaneous HSV isolates demonstrated ACV-sensitive virus in 2 HSV-1 HSE patients, whereas in two HSV-2 HSE patients ACVR virus was detected in the absence of known ACVR-associated TK mutations. In conclusion, we did not detect intrathecal ACVR-associated TK mutations in HSV isolates obtained from 12 HSE patients. PMID:27171421

  6. Prevalence of Intrathecal Acyclovir Resistant Virus in Herpes Simplex Encephalitis Patients

    PubMed Central

    Mitterreiter, Johanna G.; Titulaer, Maarten J.; van Nierop, Gijsbert P.; van Kampen, Jeroen J. A.; Aron, Georgina I.; Osterhaus, Albert D. M. E.; Verjans, Georges M. G. M.; Ouwendijk, Werner J. D.

    2016-01-01

    Herpes simplex encephalitis (HSE) is a life-threatening complication of herpes simplex virus (HSV) infection. Acyclovir (ACV) is the antiviral treatment of choice, but may lead to emergence of ACV-resistant (ACVR) HSV due to mutations in the viral UL23 gene encoding for the ACV-targeted thymidine kinase (TK) protein. Here, we determined the prevalence of intrathecal ACVR–associated HSV TK mutations in HSE patients and compared TK genotypes of sequential HSV isolates in paired cerebrospinal fluid (CSF) and blister fluid of mucosal HSV lesions. Clinical samples were obtained from 12 HSE patients, encompassing 4 HSV type 1 (HSV-1) and 8 HSV-2 encephalitis patients. HSV DNA load was determined by real-time PCR and complete HSV TK gene sequences were obtained by nested PCR followed by Sanger sequencing. All HSV-1 HSE patients contained viral TK mutations encompassing 30 unique nucleotide and 13 distinct amino acid mutations. By contrast, a total of 5 unique nucleotide and 4 distinct amino acid changes were detected in 7 of 8 HSV-2 patients. Detected mutations were identified as natural polymorphisms located in non-conserved HSV TK gene regions. ACV therapy did not induce the emergence of ACVR-associated HSV TK mutations in consecutive CSF and mucocutaneous samples of 5 individual patients. Phenotypic susceptibility analysis of these mucocutaneous HSV isolates demonstrated ACV-sensitive virus in 2 HSV-1 HSE patients, whereas in two HSV-2 HSE patients ACVR virus was detected in the absence of known ACVR-associated TK mutations. In conclusion, we did not detect intrathecal ACVR-associated TK mutations in HSV isolates obtained from 12 HSE patients. PMID:27171421

  7. Detection of West Nile virus genome and specific antibodies in Iranian encephalitis patients.

    PubMed

    Chinikar, S; Javadi, A; Ataei, B; Shakeri, H; Moradi, M; Mostafavi, E; Ghiasi, S M

    2012-08-01

    West Nile virus (WNV) is a mosquito-borne flavivirus which circulates in birds, horses and humans. An estimated 80% of WNV infections are asymptomatic. Fewer than 1% of infected persons develop neuroinvasive disease, which typically presents as encephalitis, meningitis, or acute flaccid paralysis. This study was conducted from January 2008 to June 2009 in Isfahan, Iran. Patients attending the emergency department with fever and loss of consciousness were consecutively included. Cerebrospinal fluids (CSF) were initially analysed through bacteriology and biochemistry examinations, resulting in those with evidence of meningitis being excluded. Patients' CSF and serum were diagnosed by serological and molecular assays. A total of 632 patients with fever and loss of consciousness were tested by CSF analyses. Samples of the remaining patients (39·4%) were referred for WNV investigation. Three (1·2%) of the patients were positive for both serum and CSF by RT-PCR, and six (2·4%) were positive only for IgG antibodies. History of insect bite, and blood transfusion and transplantation were risk factors for being positive by RT-PCR (P=0·048) and being IgG positive (P=0·024), respectively. The results of this study showed that the prevalence of West Nile fever is low in patients with encephalitis. PMID:22008154

  8. Mortality of captive whooping cranes caused by eastern equine encephalitis virus

    USGS Publications Warehouse

    Dein, F.J.; Carpenter, J.W.; Clark, G.G.; Montali, R.J.; Crabbs, C.L.; Tsai, T.F.; Docherty, D.E.

    1986-01-01

    Of 39 captive whooping cranes (Grus americana), 7 died during a 7-week period (Sept 17 through Nov 4, 1984) at the Patuxent Wildlife Research Center, Laurel, Md. Before their deaths, 4 cranes did not develop clinical signs, whereas the other 3 cranes were lethargic and ataxic, with high aspartate transaminase, gamma-glutamyl transferase, and lactic acid dehydrogenase activities, and high uric acid concentrations. Necropsies indicated that the birds had ascites, intestinal mucosal discoloration, fat depletion, hepatomegaly, splenomegaly, and visceral gout. Microscopically, extensive necrosis and inflammation were seen in many visceral organs; the CNS was not affected. Eastern equine encephalitis (EEE) virus was isolated from specimens of the livers, kidneys, lungs, brains, and intestines of 4 of the 7 birds that died, and EEE virus-neutralizing antibody was detected in 14 (44%) of the 32 surviving birds. Other infectious or toxic agents were not found. Morbidity or mortality was not detected in 240 sandhill cranes (Grus canadensis) interspersed among the whooping cranes; however, 13 of the 32 sandhill cranes evaluated had EEE virus-neutralizing antibody. Of the 41 wild birds evaluated in the area, 3 (4%) had EEE virus-neutralizing antibody. Immature Culiseta melanura (the most probable mosquito vector) were found in scattered foci 5 km from the research center.

  9. Antigenic and immunogenic properties of defined physical forms of tick-borne encephalitis virus structural proteins.

    PubMed Central

    Heinz, F X; Tuma, W; Kunz, C

    1981-01-01

    Polymeric, delipidated glycoprotein complexes of defined size and composition were prepared from tick-borne encephalitis virus by solubilization with Triton X-100 or cetyltrimethylammonium bromide, followed by centrifugation into detergent-free sucrose density gradients. The antigenic reactivities and immunogenicities of these complexes were compared with those of complete inactivated virus. These glycoprotein preparations induced hemagglutination-inhibiting and neutralizing antibodies which proved to be protective in passive mouse protection tests and monospecifically reacted only with the viral envelope and not with the internal core. In a competitive radioimmunoassay the glycoprotein complexes revealed about 10-fold higher antigenicity than whole virus when tested at equal protein concentrations. The important implications of these results with respect to antigen quantification in vaccines are discussed. As shown in the mouse challenge potency test, glycoprotein complexes prepared after Triton X-100 solubilization actively protected mice almost as well as did complete inactivated virus at the same protein concentration, whereas those prepared after cetyltrimethylammonium bromide solubilization had a somewhat lower protective activity per microgram of protein. Images PMID:7263062

  10. Impact of naled (Dibrom 14) on the mosquito vectors of eastern equine encephalitis virus.

    PubMed

    Howard, J J; Oliver, J

    1997-12-01

    In central New York, aerial mosquito adulticide applications have been used in response to eastern equine encephalitis (EEE) outbreaks and have targeted the swamp habitats of the primary enzootic vector of EEE virus, Culiseta melanura (Coquillett). The organophosphate insecticide naled (1, 2, dibromo-2, 2-dichloroethyl dimethyl phosphate) has been the insecticide of choice in this region. This study reports on analyses of 11 years (1984-94) of mosquito collection data from Cicero and Toad Harbor swamps in relation to applications of naled. Naled applications were successful in achieving short-term reductions in mosquito abundance. However, despite repetitive applications, populations of the primary vector of EEE virus, Cs. melanura, have increased 15-fold at Cicero Swamp. Preventive applications had no noticeable impact on the enzootic amplification of EEE virus, and isolations of virus following preventive applications have resulted in additional spraying. The possibility that applications of naled contributed to increased populations of Cs. melanura discredits the rationale that preventive applications of naled reduce the risk of EEE. PMID:9474556

  11. Serological survey of caprine arthritis-encephalitis virus infection in Japan

    PubMed Central

    KONISHI, Misako; HAYAMA, Yoko; SHIRAFUJI, Hiroaki; KAMEYAMA, Ken-ichiro; MURAKAMI, Kenji; TSUTSUI, Toshiyuki; AKASHI, Hiroomi

    2015-01-01

    A serological survey of caprine arthritis-encephalitis virus (CAEV) infection was conducted from September 2006 to February 2007 in Japan. A total of 857 serum samples were collected from 113 herds in 28 prefectures and were analyzed for the presence of CAEV antibodies using agar gel immunodiffusion test. The seroprevalence of CAEV infection at the herd and animal levels was 15.0% (17/113) and 10.0% (86/857), respectively. Large farms with more than 10 goats and with animals for dairy and breeding purposes had higher seroprevalence (P<0.05). The results of this study provide useful information to consider effective control programs against CAEV infection in Japan. PMID:26498401

  12. IRES-Containing VEEV Vaccine Protects Cynomolgus Macaques from IE Venezuelan Equine Encephalitis Virus Aerosol Challenge

    PubMed Central

    Rossi, Shannan L.; Russell-Lodrigue, Kasi E.; Killeen, Stephanie Z.; Wang, Eryu; Leal, Grace; Bergren, Nicholas A.; Vinet-Oliphant, Heather; Weaver, Scott C.; Roy, Chad J.

    2015-01-01

    Venezuelan equine encephalitis virus (VEEV) is an arbovirus endemic to the Americas that is responsible for severe, sometimes fatal, disease in humans and horses. We previously described an IRES-based VEE vaccine candidate based up the IE serotype that offers complete protection against a lethal subtype IE VEEV challenge in mice. Here we demonstrate the IRES-based vaccine’s ability to protect against febrile disease in cynomolgus macaques. Vaccination was well tolerated and elicited robust neutralizing antibody titers noticed as early as day 14. Moreover, complete protection from disease characterized by absence of viremia and characteristic fever following aerosolized IE VEEV challenge was observed in all vaccinees compared to control animals, which developed clinical disease. Together, these results highlight the safety and efficacy of IRES-based VEEV vaccine to protect against an endemic, pathogenic VEEV IE serotype. PMID:26020513

  13. Eastern equine encephalitis virus in birds: relative competence of European starlings (Sturnus vulgaris).

    PubMed

    Komar, N; Dohm, D J; Turell, M J; Spielman, A

    1999-03-01

    To determine whether eastern equine encephalitis (EEE) virus infection in starlings may be more fulminant than in various native candidate reservoir birds, we compared their respective intensities and durations of viremia. Viremias are more intense and longer lasting in starlings than in robins and other birds. Starlings frequently die as their viremia begins to wane; other birds generally survive. Various Aedes as well as Culiseta melanura mosquitoes can acquire EEE viral infection from infected starlings under laboratory conditions. The reservoir competence of a bird is described as the product of infectiousness (proportion of feeding mosquitoes that become infected) and the duration of infectious viremia. Although starlings are not originally native where EEE is enzootic, a starling can infect about three times as many mosquitoes as can a robin. PMID:10466964

  14. Transient widespread cortical and splenial lesions in acute encephalitis/encephalopathy associated with primary Epstein-Barr virus infection.

    PubMed

    Zhang, Shuo; Feng, Juan; Shi, Yifang

    2016-01-01

    Infection with Epstein-Barr virus (EBV) is very common and usually occurs in childhood or early adulthood. Encephalitis/encephalopathy is an uncommon but serious neurological complication of EBV. A case of EBV-associated encephalitis/encephalopathy with involvement of reversible widespread cortical and splenial lesions is presented herein. An 8-year-old Chinese girl who presented with fever and headache, followed by seizures and drowsiness, was admitted to the hospital. Magnetic resonance imaging revealed high signal intensities on diffusion-weighted imaging in widespread cortical and splenial lesions. The clinical and laboratory examination results together with the unusual radiology findings suggested acute encephalitis/encephalopathy due to primary EBV infection. After methylprednisolone pulse therapy together with ganciclovir, the patient made a full recovery without any brain lesions. The hallmark clinical-radiological features of this patient included severe encephalitis/encephalopathy at onset, the prompt and complete recovery, and rapidly reversible widespread involvement of the cortex and splenium. Patients with EBV encephalitis/encephalopathy who have multiple lesions, even with the widespread involvement of cortex and splenium of the corpus callosum, may have a favorable outcome with complete disappearance of all brain lesions. PMID:26600186

  15. Widespread Detection of Antibodies to Eastern Equine Encephalitis, West Nile, St. Louis Encephalitis, and Turlock Viruses in Various Species of Wild Birds from Across the United States.

    PubMed

    Pedersen, Kerri; Marks, David R; Wang, Eryu; Eastwood, Gillian; Weaver, Scott C; Goldstein, Samuel M; Sinnett, David R; DeLiberto, Thomas J

    2016-07-01

    Wild birds serve as amplifying hosts for many arboviruses, and are thought to be responsible for introducing these viruses into new areas during migration as well as reintroducing them to places where winter temperatures disrupt mosquito-borne transmission. To learn more about four mosquito-borne arboviruses of concern to human or animal health, we tested sera from 997 wild birds of 54 species and 17 families across 44 states of the United States collected from January 1, 2013, through September 30, 2013. Samples were tested for antibody against eastern equine encephalitis, St. Louis encephalitis, West Nile, and Turlock viruses using plaque reduction neutralization tests with an endpoint of 80% or greater. Of the 333 (33.4%) birds that tested positive for antibody to at least one arbovirus, 29.7% were exposed to two or more arboviruses. Exposure to all four arboviruses was detected in Canada geese, double-crested cormorants, mallards, mute swans, laughing gulls, and American coots. Our results suggest that exposure to arboviruses is widespread in the United States across a diversity of wild bird species. PMID:27162269

  16. Characterization of enzootic foci of Venezuelan equine encephalitis virus in western Venezuela.

    PubMed

    Barrera, R; Torres, N; Freier, J E; Navarro, J C; García, C Z; Salas, R; Vasquez, C; Weaver, S C

    2001-01-01

    The distribution of the sylvatic subtype ID Venezuelan equine encephalitis (VEE) viruses in the lowland tropical forests of western Venezuela was investigated using remote sensing and geographic information system technologies. Landsat 5 Thematic Mapper satellite imagery was used to study the reflectance patterns of VEE endemic foci and to identify other locations with similar reflectance patterns. Enzootic VEE virus variants isolated during this study are the closest genetic relatives of the epizootic viruses that emerged in western Venezuela during 1992-1993. VEE virus surveillance was conducted by exposing sentinel hamsters to mosquito bites and trapping wild vertebrates in seven forests identified and located by means of the satellite image. We isolated VEE viruses from 48 of a total of 1,363 sentinel hamsters in two of the forests on six occasions, in both dry and wet seasons. None of the 12 small vertebrates captured in 8,190 trap-nights showed signs of previous VEE virus infection. The satellite image was classified into 13 validated classes of land use/vegetation using unsupervised and supervised techniques. Data derived from the image consisted of the raw digital values of near- and mid-infrared bands 4, 5, and 7, derived Tasseled Cap indices of wetness, greenness, and brightness, and the Normalized Difference Vegetation Index. Digitized maps provided ancillary data of elevation and soil geomorphology. Image enhancement was applied using Principal Component Analysis. A digital layer of roads together with georeferenced images was used to locate the study sites. A cluster analysis using the above data revealed two main groups of dense forests separated by spectral properties, altitude, and soil geomorphology. Virus was isolated more frequently from the forest type identified on flat flood plains of main rivers rather than the forest type found on the rolling hills of the study area. The spatial analysis suggests that mosquitoes carrying the enzootic viruses

  17. Surveys for Antibodies Against Mosquitoborne Encephalitis Viruses in California Birds, 1996-2013.

    PubMed

    Reisen, William K; Wheeler, Sarah S

    2016-04-01

    From 1996 through 2013, 54,546 individual birds comprising 152 species and 7 orders were banded, bled, and released at four study areas within California, from which 28,388 additional serum samples were collected at one or more recapture encounters. Of these, 142, 99, and 1929 birds from 41 species were positive for neutralizing antibodies against western equine encephalomyelitis virus (WEEV), St. Louis encephalitis virus (SLEV), or West Nile virus (WNV) at initial capture or recapture, respectively. Overall, 83% of the positive serum samples were collected from five species: House Finch, House Sparrow, Mourning Dove, California Quail, and Western Scrub-Jay. Temporal data supported concurrent arbovirus surveillance and documented the disappearance of birds positive for WEEV in 2008 and SLEV in 2003 and the appearance of birds positive for WNV after its invasion in 2003. Results of these serosurveys agreed well with the host selection patterns of the Culex vectors as described from bloodmeal sequencing data and indicated that transmission of WNV seemed most effective within urban areas where avian and mosquito host diversity was limited to relatively few competent species. PMID:26974395

  18. Electron Tomography Analysis of Tick-Borne Encephalitis Virus Infection in Human Neurons.

    PubMed

    Bílý, Tomáš; Palus, Martin; Eyer, Luděk; Elsterová, Jana; Vancová, Marie; Růžek, Daniel

    2015-01-01

    Tick-borne encephalitis virus (TBEV) causes serious, potentially fatal neurological infections that affect humans in endemic regions of Europe and Asia. Neurons are the primary target for TBEV infection in the central nervous system. However, knowledge about this viral infection and virus-induced neuronal injury is fragmental. Here, we directly examined the pathology that occurs after TBEV infection in human primary neurons. We exploited the advantages of advanced high-pressure freezing and freeze-substitution techniques to achieve optimal preservation of infected cell architecture. Electron tomographic (ET) reconstructions elucidated high-resolution 3D images of the proliferating endoplasmic reticulum, and individual tubule-like structures of different diameters in the endoplasmic reticulum cisternae of single cells. ET revealed direct connections between the tubule-like structures and viral particles in the endoplasmic reticulum. Furthermore, ET showed connections between cellular microtubules and vacuoles that harbored the TBEV virions in neuronal extensions. This study was the first to characterize the 3D topographical organization of membranous whorls and autophagic vacuoles in TBEV-infected human neurons. The functional importance of autophagy during TBEV replication was studied in human neuroblastoma cells; stimulation of autophagy resulted in significantly increased dose-dependent TBEV production, whereas the inhibition of autophagy showed a profound, dose-dependent decrease of the yield of infectious virus. PMID:26073783

  19. Electron Tomography Analysis of Tick-Borne Encephalitis Virus Infection in Human Neurons

    PubMed Central

    Bílý, Tomáš; Palus, Martin; Eyer, Luděk; Elsterová, Jana; Vancová, Marie; Růžek, Daniel

    2015-01-01

    Tick-borne encephalitis virus (TBEV) causes serious, potentially fatal neurological infections that affect humans in endemic regions of Europe and Asia. Neurons are the primary target for TBEV infection in the central nervous system. However, knowledge about this viral infection and virus-induced neuronal injury is fragmental. Here, we directly examined the pathology that occurs after TBEV infection in human primary neurons. We exploited the advantages of advanced high-pressure freezing and freeze-substitution techniques to achieve optimal preservation of infected cell architecture. Electron tomographic (ET) reconstructions elucidated high-resolution 3D images of the proliferating endoplasmic reticulum, and individual tubule-like structures of different diameters in the endoplasmic reticulum cisternae of single cells. ET revealed direct connections between the tubule-like structures and viral particles in the endoplasmic reticulum. Furthermore, ET showed connections between cellular microtubules and vacuoles that harbored the TBEV virions in neuronal extensions. This study was the first to characterize the 3D topographical organization of membranous whorls and autophagic vacuoles in TBEV-infected human neurons. The functional importance of autophagy during TBEV replication was studied in human neuroblastoma cells; stimulation of autophagy resulted in significantly increased dose-dependent TBEV production, whereas the inhibition of autophagy showed a profound, dose-dependent decrease of the yield of infectious virus. PMID:26073783

  20. Consequences of in vitro host shift for St. Louis encephalitis virus

    PubMed Central

    Payne, Anne F.; Ngo, Kiet A.; Kramer, Laura D.

    2014-01-01

    Understanding the potential for host range shifts and expansions of RNA viruses is critical to predicting the evolutionary and epidemiological paths of these pathogens. As arthropod-borne viruses (arboviruses) experience frequent spillover from their amplification cycles and are generalists by nature, they are likely to experience a relatively high frequency of success in a range of host environments. Despite this, the potential for host expansion, the genetic correlates of adaptation to novel environments and the costs of such adaptations in originally competent hosts are still not characterized fully for arboviruses. In the studies presented here, we utilized experimental evolution of St. Louis encephalitis virus (SLEV; family Flaviviridae, genus Flavivirus) in vitro in the Dermacentor andersoni line of tick cells to model adaptation to a novel invertebrate host. Our results demonstrated that levels of adaptation and costs in alternate hosts are highly variable among lineages, but also that significant fitness increases in tick cells are achievable with only modest change in consensus genetic sequence. In addition, although accumulation of diversity may at times buffer against phenotypic costs within the SLEV swarm, an increased proportion of variants with an impaired capacity to infect and spread on vertebrate cell culture accumulated with tick cell passage. Isolation and characterization of a subset of these variants implicates the NS3 gene as an important host range determinant for SLEV. PMID:24643879

  1. Consequences of in vitro host shift for St. Louis encephalitis virus.

    PubMed

    Ciota, Alexander T; Payne, Anne F; Ngo, Kiet A; Kramer, Laura D

    2014-06-01

    Understanding the potential for host range shifts and expansions of RNA viruses is critical to predicting the evolutionary and epidemiological paths of these pathogens. As arthropod-borne viruses (arboviruses) experience frequent spillover from their amplification cycles and are generalists by nature, they are likely to experience a relatively high frequency of success in a range of host environments. Despite this, the potential for host expansion, the genetic correlates of adaptation to novel environments and the costs of such adaptations in originally competent hosts are still not characterized fully for arboviruses. In the studies presented here, we utilized experimental evolution of St. Louis encephalitis virus (SLEV; family Flaviviridae, genus Flavivirus) in vitro in the Dermacentor andersoni line of tick cells to model adaptation to a novel invertebrate host. Our results demonstrated that levels of adaptation and costs in alternate hosts are highly variable among lineages, but also that significant fitness increases in tick cells are achievable with only modest change in consensus genetic sequence. In addition, although accumulation of diversity may at times buffer against phenotypic costs within the SLEV swarm, an increased proportion of variants with an impaired capacity to infect and spread on vertebrate cell culture accumulated with tick cell passage. Isolation and characterization of a subset of these variants implicates the NS3 gene as an important host range determinant for SLEV. PMID:24643879

  2. A chimeric Sindbis-based vaccine protects cynomolgus macaques against a lethal aerosol challenge of eastern equine encephalitis virus

    PubMed Central

    Roy, Chad J.; Adams, A. Paige; Wang, Eryu; Leal, Grace; Seymour, Robert L.; Sivasubramani, Satheesh K.; Mega, William; Frolov, Ilya; Didier, Peter J.; Weaver, Scott C.

    2013-01-01

    Eastern equine encephalitis virus (EEEV) is a mosquito-borne alphavirus that causes sporadic, often fatal disease outbreaks in humans and equids, and is also a biological threat agent. Two chimeric vaccine candidates were constructed using a cDNA clone with a Sindbis virus (SINV) backbone and structural protein genes from either a North (SIN/NAEEEV) or South American (SIN/SAEEEV) strain of EEEV. The vaccine candidates were tested in a nonhuman primate (NHP) model of eastern equine encephalitis (EEE). Cynomolgus macaques were either sham-vaccinated, or vaccinated with a single dose of either SIN/NAEEEV or SIN/SAEEEV. After vaccination, animals were challenged by aerosol with a virulent North American strain of EEEV (NA EEEV). The SIN/NAEEEV vaccine provided significant protection, and most vaccinated animals survived EEEV challenge (82%) with little evidence of disease, whereas most SIN/SAEEEV-vaccinated (83%) and control (100%) animals died. Protected animals exhibited minimal changes in temperature and cardiovascular rhythm, whereas unprotected animals showed profound hyperthermia and changes in heart rate post-exposure. Acute inflammation and neuronal necrosis were consistent with EEEV-induced encephalitis in unprotected animals, whereas no encephalitis-related histopathologic changes were observed in the SIN/NAEEEV-vaccinated animals. These results demonstrate that the chimeric SIN/NAEEEV vaccine candidate protects against an aerosol EEEV exposure. PMID:23333212

  3. The Spatio-temporal Distribution of Japanese Encephalitis Cases in Different Age Groups in Mainland China, 2004 – 2014

    PubMed Central

    Wang, Huanyu; Song, Miao; Li, Minghua; Fu, Shihong; Lv, Zhi; He, Ying; Lei, Wenwen; Wang, Bin; Lu, Xiaoqing; Liang, Guodong

    2016-01-01

    Background Japanese encephalitis (JE) is very prevalent in China, but the incidence of JE among children has been greatly reduced by extensive promotion of vaccinations. The incidence of JE among adults, however, has increased in some parts of China. Methods/Principal Findings Data on JE in mainland China, in terms of incidence, gender, and age, were collected between 2004 and 2014. We conducted spatial and temporal analyses on data from different age groups. Generally, children aged 0–15 years still represent the major population of JE cases in China, despite the gradual decrease in incidence over years. However, the incidence of JE among adults in several provinces is notably higher than the national average, especially during the epidemic waves in 2006, 2009, and 2013. The JE cases in the 0–15-year-old group are distributed mainly in the area south of the Yangtze River, with peak incidence occurring from July to September. In the adult group, especially for those over 40 years old, the JE cases are concentrated mainly in the area north of the Yangtze River. JE incidence in the adult group in September and October is significantly greater compared to the other groups. Further analysis using Local Indicators of Spatial Association (LISA) reveals that the distribution of adult JE cases in the six provinces north of the Yangtze River, between north 30–35° latitude and east 110–130° longitude, is a hotspot for adult JE cases. Conclusions/Significance The rate of JE case increase for adults is much greater than for children and has become a public health issue. Therefore, studies on the necessity and feasibility of vaccinating adults who live in JE-endemic areas, but have never been vaccinated for JE, should become a new focus of JE prevention in the future. PMID:27050414

  4. Vector-host interactions and epizootiology of eastern equine encephalitis virus in Massachusetts.

    PubMed

    Molaei, Goudarz; Andreadis, Theodore G; Armstrong, Philip M; Thomas, Michael C; Deschamps, Timothy; Cuebas-Incle, Esteban; Montgomery, Walter; Osborne, Matthew; Smole, Sandra; Matton, Priscilla; Andrews, Wayne; Best, Curtis; Cornine, Frank; Bidlack, Ellen; Texeira, Tony

    2013-05-01

    Eastern equine encephalitis (EEE) virus is a highly pathogenic mosquito-borne zoonosis that is responsible for outbreaks of severe disease in humans and equines, resulting in high mortality or severe neurological impairment in most survivors. In the northeastern United States, EEE virus is maintained in an enzootic cycle involving the ornithophilic mosquito, Culiseta melanura (Coquillett) and passerine birds in freshwater swamp habitats. To evaluate the role of Cs. melanura and Culiseta morsitans (Theobald) in recent episodes of EEE virus activity in Massachusetts, we collected blood-fed mosquitoes between June, 2007, and October, 2008, from virus foci in 6 counties, and identified the source of blood meals by PCR amplification of mitochondrial cytochrome b gene and sequencing. Analysis of 529 Cs. melanura and 25 Cs. morsitans revealed that nearly 99% and 96% of mosquitoes, respectively, acquired blood meals solely from avian hosts. American Robin, Turdus migratorius Linnaeus was identified as the most common vertebrate host for Cs. melanura (21.7%, n=115), followed by Tufted Titmouse, Baeolophus bicolor (L.) (8.7%, n=46), Black-capped Chickadee, Poecile atricapillus (L.) (8.5%, n=45), Scarlet Tanager, Piranga olivacea (Gmelin) (6.8%, n=36), Field Sparrow, Spizella pusilla (Wilson) (6.2%, n=33), Northern Cardinal, Cardinalis cardinalis (L.) (5.7%, n=30), and other mostly Passeriformes birds. Mammalian-derived blood meals were identified as white-tailed deer, Odocoileus virginianus Zimmermann, domestic cow, Bos taurus L., and human, Homo sapiens L. There were 4 isolations of EEE virus, West Nile virus, and Highland J virus from Cs. melanura. Our results in conjunction with other lines of evidence, including reservoir competency, prevalence of antibody, and infection in nature, suggest that the American Robin, Tufted Titmouse, Black-capped Chickadee, and a few other passerine birds may play key roles in supporting EEE virus transmission in Massachusetts. Infrequent

  5. Discovery of a Novel Compound with Anti-Venezuelan Equine Encephalitis Virus Activity That Targets the Nonstructural Protein 2

    PubMed Central

    Chung, Dong-Hoon; Jonsson, Colleen B.; Tower, Nichole A.; Chu, Yong-Kyu; Sahin, Ergin; Golden, Jennifer E.; Noah, James W.; Schroeder, Chad E.; Sotsky, Julie B.; Sosa, Melinda I.; Cramer, Daniel E.; McKellip, Sara N.; Rasmussen, Lynn; White, E. Lucile; Schmaljohn, Connie S.; Julander, Justin G.; Smith, Jeffrey M.; Filone, Claire Marie; Connor, John H.; Sakurai, Yasuteru; Davey, Robert A.

    2014-01-01

    Alphaviruses present serious health threats as emerging and re-emerging viruses. Venezuelan equine encephalitis virus (VEEV), a New World alphavirus, can cause encephalitis in humans and horses, but there are no therapeutics for treatment. To date, compounds reported as anti-VEEV or anti-alphavirus inhibitors have shown moderate activity. To discover new classes of anti-VEEV inhibitors with novel viral targets, we used a high-throughput screen based on the measurement of cell protection from live VEEV TC-83-induced cytopathic effect to screen a 340,000 compound library. Of those, we identified five novel anti-VEEV compounds and chose a quinazolinone compound, CID15997213 (IC50 = 0.84 µM), for further characterization. The antiviral effect of CID15997213 was alphavirus-specific, inhibiting VEEV and Western equine encephalitis virus, but not Eastern equine encephalitis virus. In vitro assays confirmed inhibition of viral RNA, protein, and progeny synthesis. No antiviral activity was detected against a select group of RNA viruses. We found mutations conferring the resistance to the compound in the N-terminal domain of nsP2 and confirmed the target residues using a reverse genetic approach. Time of addition studies showed that the compound inhibits the middle stage of replication when viral genome replication is most active. In mice, the compound showed complete protection from lethal VEEV disease at 50 mg/kg/day. Collectively, these results reveal a potent anti-VEEV compound that uniquely targets the viral nsP2 N-terminal domain. While the function of nsP2 has yet to be characterized, our studies suggest that the protein might play a critical role in viral replication, and further, may represent an innovative opportunity to develop therapeutic interventions for alphavirus infection. PMID:24967809

  6. Tick-borne encephalitis.

    PubMed

    Gritsun, T S; Lashkevich, V A; Gould, E A

    2003-01-01

    Tick-borne encephalitis (TBE) is one of the most dangerous human infections occurring in Europe and many parts of Asia. The etiological agent Tick-borne encephalitis virus (TBEV), is a member of the virus genus Flavivirus, of the family Flaviviridae. TBEV is believed to cause at least 11,000 human cases of encephalitis in Russia and about 3000 cases in the rest of Europe annually. Related viruses within the same group, Louping ill virus (LIV), Langat virus (LGTV) and Powassan virus (POWV), also cause human encephalitis but rarely on an epidemic scale. Three other viruses within the same group, Omsk hemorrhagic fever virus (OHFV), Kyasanur Forest disease virus (KFDV) and Alkhurma virus (ALKV), are closely related to the TBEV complex viruses and tend to cause fatal hemorrhagic fevers rather than encephalitis. This review describes the clinical manifestations associated with TBEV infections, the main molecular-biological properties of these viruses, and the different factors that define the incidence and severity of disease. The role of ticks and their local hosts in the emergence of new virus variants with different pathogenic characteristics is also discussed. This review also contains a brief history of vaccination against TBE including trials with live attenuated vaccine and modern tendencies in developing of vaccine virus strains. PMID:12615309

  7. SAINT LOUIS ENCEPHALITIS VIRUS IN MATO GROSSO, CENTRAL-WESTERN BRAZIL

    PubMed Central

    HEINEN, Letícia Borges da Silva; ZUCHI, Nayara; SERRA, Otacília Pereira; CARDOSO, Belgath Fernandes; GONDIM, Breno Herman Ferreira; dos SANTOS, Marcelo Adriano Mendes; SOUTO, Francisco José Dutra; de PAULA, Daphine Ariadne Jesus; DUTRA, Valéria; DEZENGRINI-SLHESSARENKO, Renata

    2015-01-01

    The dengue virus (DENV), which is frequently involved in large epidemics, and the yellow fever virus (YFV), which is responsible for sporadic sylvatic outbreaks, are considered the most important flaviviruses circulating in Brazil. Because of that, laboratorial diagnosis of acute undifferentiated febrile illness during epidemic periods is frequently directed towards these viruses, which may eventually hinder the detection of other circulating flaviviruses, including the Saint Louis encephalitis virus (SLEV), which is widely dispersed across the Americas. The aim of this study was to conduct a molecular investigation of 11 flaviviruses using 604 serum samples obtained from patients during a large dengue fever outbreak in the state of Mato Grosso (MT) between 2011 and 2012. Simultaneously, 3,433 female Culex spp. collected with Nasci aspirators in the city of Cuiabá, MT, in 2013, and allocated to 409 pools containing 1-10 mosquitoes, were also tested by multiplex semi-nested reverse transcription PCR for the same flaviviruses. SLEV was detected in three patients co-infected with DENV-4 from the cities of Cuiabá and Várzea Grande. One of them was a triple co-infection with DENV-1. None of them mentioned recent travel or access to sylvatic/rural regions, indicating that transmission might have occurred within the metropolitan area. Regarding mosquito samples, one pool containing one Culex quinquefasciatus female was positive for SLEV, with a minimum infection rate (MIR) of 0.29 per 1000 specimens of this species. Phylogenetic analysis indicates both human and mosquito SLEV cluster, with isolates from genotype V-A obtained from animals in the Amazon region, in the state of Pará. This is the first report of SLEV molecular identification in MT. PMID:26200961

  8. Isolation and Phylogenetic Analysis of Mucambo Virus (Venezuelan Equine Encephalitis Complex Subtype IIIA) in Trinidad

    PubMed Central

    Auguste, Albert J.; Volk, Sara M.; Arrigo, Nicole C.; Martinez, Raymond; Ramkissoon, Vernie; Adams, A. Paige; Thompson, Nadin N.; Adesiyun, Abiodun A.; Chadee, Dave D.; Foster, Jerome E.; Travassos Da Rosa, Amelia P.A.; Tesh, Robert B.; Weaver, Scott C.; Carrington, Christine V. F.

    2009-01-01

    In the 1950s and 1960s, alphaviruses in the Venezuelan equine encephalitis (VEE) antigenic complex were the most frequently isolated arboviruses in Trinidad. Since then, there has been very little research performed with these viruses. Herein, we report on the isolation, sequencing, and phylogenetic analyses of Mucambo virus (MUCV; VEE complex subtype IIIA), including 6 recently isolated from Culex (Melanoconion) portesi mosquitoes and 11 previously isolated in Trinidad and Brazil. Results show that nucleotide and amino acid identities across the complete structural polyprotein for the MUCV isolates were 96.6 – 100% and 98.7 – 100%, respectively, and the phylogenetic tree inferred for MUCV was highly geographically- and temporally- structured. Bayesian analyses suggest the sampled MUCV lineages have a recent common ancestry of approximately 198 years (with a 95% highest posterior density (HPD) interval of 63 – 448 years) prior to 2007, and an overall rate of evolution of 1.28 × 10−4 substitutions/site/yr. PMID:19631956

  9. Quantitative autoradiographic mapping of herpes simplex virus encephalitis with a radiolabeled antiviral drug

    SciTech Connect

    Saito, Y.; Price, R.W.; Rottenberg, D.A.; Fox, J.J.; Su, T.L.; Watanabe, K.A.; Philips, F.S.

    1982-09-17

    2'-Fluoro-5-methyl-1-..beta..-D-arabinosyluracil (FMAU) labeled with carbon-14 was used to image herpes simplex virus type 1-infected regions of rat brain by quantitative autoradiography. FMAU is a potent antiviral pyrimidine nucleoside which is selectively phosphorylated by virus-coded thymidine kinase. When the labeled FMAU was administered 6 hours before the rats were killed, the selective uptake and concentration of the drug and its metabolites by infected cells (defined by immunoperoxidase staining of viral antigens) allowed quantitative definition and mapping of HSV-1-infected structures in autoradiograms of brain sections. These results shown that quantitative autoradiography can be used to characterize the local metabolism of antiviral drugs by infected cells in vivo. They also suggest that the selective uptake of drugs that exploit viral thymidine kinase for their antiviral effect can, by appropriate labeling, be used in conjunction with clinical neuroimaging techniques to define infected regions of human brain, thereby providing a new approach to the diagnosis of herpes encephalitis in man.

  10. Medical and molecular perspectives into a forgotten epidemic: encephalitis lethargica, viruses, and high-throughput sequencing.

    PubMed

    Tappe, Dennis; Alquezar-Planas, David E

    2014-10-01

    The emergence of encephalitis lethargica (EL), an acute-onset polioencephalitis of unknown etiology as an epidemic in the years 1917-1925 is still unexplainable today. Questioned by the first descriptor of EL himself, Constantin von Economo, there has been much debate shrouding a possible role of the "Spanish" H1N1 influenza A pandemic virus in the development of EL. Previous molecular studies employing conventional PCR for the detection of influenza A virus RNA in archived human brain samples from patients who died of acute EL were negative. However, the clinical and laboratory characteristics of EL and its epidemiology are consistent with an infectious disease, and recently a possible enterovirus cause was investigated. With the rapid development of high-throughput sequencing, new information about a possible viral etiology can be obtained if sufficient specimens for analysis were still available today. Here, we discuss the implications of these technologies for the investigation of a possible infectious cause of EL from archived material, as well as a prospectus for future work for acquiring viral nucleic acids from these sources. PMID:25129855

  11. Manipulation of host factors optimizes the pathogenesis of western equine encephalitis virus infections in mice for antiviral drug development.

    PubMed

    Blakely, Pennelope K; Delekta, Phillip C; Miller, David J; Irani, David N

    2015-02-01

    While alphaviruses spread naturally via mosquito vectors, some can also be transmitted as aerosols making them potential bioterrorism agents. One such pathogen, western equine encephalitis virus (WEEV), causes fatal human encephalitis via multiple routes of infection and thus presumably via multiple mechanisms. Although WEEV also produces acute encephalitis in non-human primates, a small animal model that recapitulates features of human disease would be useful for both pathogenesis studies and to evaluate candidate antiviral therapies. We have optimized conditions to infect mice with a low passage isolate of WEEV, thereby allowing detailed investigation of virus tropism, replication, neuroinvasion, and neurovirulence. We find that host factors strongly influence disease outcome, and in particular, that age, gender, and genetic background all have significant effects on disease susceptibility independent of virus tropism or replication within the central nervous system. Our data show that experimental variables can be adjusted in mice to recapitulate disease features known to occur in both non-human primates and humans, thus aiding further study of WEEV pathogenesis and providing a realistic therapeutic window for antiviral drug delivery. PMID:25361697

  12. Manipulation of host factors optimizes the pathogenesis of western equine encephalitis virus infections in mice for antiviral drug development

    PubMed Central

    Blakely, Pennelope K.; Delekta, Phillip C.; Miller, David J.; Irani, David N.

    2014-01-01

    While alphaviruses spread naturally via mosquito vectors, some can also be transmitted as aerosols making them potential bioterrorism agents. One such pathogen, western equine encephalitis virus (WEEV), causes fatal human encephalitis via multiple routes of infection and thus presumably via multiple mechanisms. Although WEEV also produces acute encephalitis in non-human primates, a small animal model that recapitulates features of human disease would be useful for both pathogenesis studies and to evaluate candidate antiviral therapies. We have optimized conditions to infect mice with a low passage isolate of WEEV, thereby allowing detailed investigation of virus tropism, replication, neuroinvasion, and neurovirulence. We find that host factors strongly influence disease outcome, and in particular that age, gender and genetic background all have significant effects on disease susceptibility independent of virus tropism or replication within the central nervous system. Our data show that experimental variables can be adjusted in mice to recapitulate disease features known to occur in both non-human primates and humans, thus aiding further study of WEEV pathogenesis and providing a realistic therapeutic window for antiviral drug delivery. PMID:25361697

  13. Encephalitis lethargica and the influenza virus. II. The influenza pandemic of 1918/19 and encephalitis lethargica: epidemiology and symptoms*

    PubMed Central

    Foley, Paul Bernard

    2009-01-01

    This is the first of two papers which critically examine the relationship between the 1918/19 influenza pandemic and encephalitis lethargica (EL). The role of influenza in the etiology of EL was vigorously debated until 1924. It is notable, however, that the unitarian camp were largely reactive in their argumentation; while the influenza skeptics provided detail descriptions of EL and the features they argued to be unique or at least unusual, influenza supporters focused on sequentially refuting the evidence of their opponents. The impression which emerges from this debate is that the individual features identified by the skeptics were not absolutely pathognomic for EL, but, on the other hand, their combination in one disorder had not previously been described for any other disease. PMID:19707848

  14. Encephalitis lethargica and the influenza virus. III. The influenza pandemic of 1918/19 and encephalitis lethargica: neuropathology and discussion*

    PubMed Central

    Foley, Paul Bernard

    2009-01-01

    This is the second of two papers which critically examine the relationship between the 1918/19 influenza pandemic and encephalitis lethargica (EL). The role of influenza in the etiology of EL was vigorously debated until 1924. It is notable, however, that the unitarian camp were largely reactive in their argumentation; while the influenza skeptics provided detail descriptions of EL and the features they argued to be unique or at least unusual, influenza supporters focused on sequentially refuting the evidence of their opponents. The impression which emerges from this debate is that the individual features identified by the skeptics were not absolutely pathognomic for EL, but, on the other hand, their combination in one disorder had not previously been described for any other disease. PMID:19707847

  15. Establishment of the 3rd national standard for lot release testing of the Japanese encephalitis vaccine (Nakayama-NIH strain) in Korea.

    PubMed

    Lee, Sunmi; Moon, Hyungsil; Kim, Min Gyu; Kim, Do Keun; Chung, Hye Joo; Park, Yong Keun; Oh, Ho Jung

    2016-07-01

    In Korea, 2 inactivated Japanese encephalitis vaccines from Nakayama-NIH and Beijing-1 strain have been utilized to date. The 1(st) national standard for lot release testing of the JE vaccine was established in 2002. The 2(nd) national standard, established in 2007, is currently in use for JE vaccine (Nakayama-NIH strain) potency testing. However, the supply of this standard is expected to be exhausted by 2015, necessitating the establishment of a new national standard with quality equivalent to that of the existing standard. Quality control tests were performed to verify that the new standard candidate material was equivalent to that of the 2(nd) national standard, proving its appropriateness for potency testing of JE vaccine. In addition, based on the results of a collaborative study conducted among 4 institutions including Ministry of Food and Drug Safety, the potency of the new national standard material was determined to be 2.69 neutralizing-antibody titer (log10) per vial. Therefore, the newly established national standard material is expected to be used for the Japanese encephalitis vaccine lot release in Korea. PMID:26890572

  16. Establishment of the 3rd national standard for lot release testing of the Japanese encephalitis vaccine (Nakayama-NIH strain) in Korea

    PubMed Central

    Lee, Sunmi; Moon, Hyungsil; Kim, Min Gyu; Kim, Do Keun; Chung, Hye Joo; Park, Yong Keun; Oh, Ho Jung

    2016-01-01

    ABSTRACT In Korea, 2 inactivated Japanese encephalitis vaccines from Nakayama-NIH and Beijing-1 strain have been utilized to date. The 1st national standard for lot release testing of the JE vaccine was established in 2002. The 2nd national standard, established in 2007, is currently in use for JE vaccine (Nakayama-NIH strain) potency testing. However, the supply of this standard is expected to be exhausted by 2015, necessitating the establishment of a new national standard with quality equivalent to that of the existing standard. Quality control tests were performed to verify that the new standard candidate material was equivalent to that of the 2nd national standard, proving its appropriateness for potency testing of JE vaccine. In addition, based on the results of a collaborative study conducted among 4 institutions including Ministry of Food and Drug Safety, the potency of the new national standard material was determined to be 2.69 neutralizing-antibody titer (log10) per vial. Therefore, the newly established national standard material is expected to be used for the Japanese encephalitis vaccine lot release in Korea. PMID:26890572

  17. Five-year surveillance of West Nile and eastern equine encephalitis viruses in Southeastern Virginia.

    PubMed

    Loftin, Karin C; Diallo, Alpha A; Herbert, Marcia W; Phaltankar, Priyarshadan G; Yuan, Christine; Grefe, Norman; Flemming, Agnes; Foley, Kirby; Williams, Jason; Fisher, Sandra L; Elberfeld, Michael; Constantine, Juan; Burcham, Mitchell; Stallings, Valerie; Xia, Dongxiang

    2006-05-01

    To investigate the occurrence of West Nile virus (WNV) and Eastern equine encephalitis virus (EEE) in southeastern Virginia, the Bureau of Laboratories at the Norfolk Department of Public Health (NDPH) analyzed mosquito pools and the sera of sentinel chickens from the southeastern Virginia area each year from 2000 to 2004. Mosquito pool supernatants were screened for the presence of viral RNA by conventional reverse transcription polymerase chain reaction (RT-PCR) and Taqman RT-PCR with the i-Cycler. Mosquito pools were also tested for virus activity by Vero cell culture. The primary enzootic vector of WNV was Culex (Cx.) pipiens and that of EEE was Culiseta (Cs.) melanura. During the five-year surveillance period, the peak minimum infection rates (MIRs) of WNV and EEE in these mosquito species were 2.7 (2002) and 0.9 (2001), respectively. In 2003, the MIRs in Cs. melanura for WNV and EEE were 0.24 and 0.56, respectively; and the MIR for WNV in Cx. pipiens was 0.64. In 2004, Cs. melanura was less active in the WNV transmission cycle (MIR = 0.07) than was Cx. pipiens (MIR = 1.8), and Cs. melanura was the only vector for EEE (MIR = 0.37). The trend was for EEE activity to peak in July; WNV activity peaked in August. Sentinel-chicken sera were tested for IgM antibodies, and peak IgM seroconversions to these arboviruses were recorded in August 2003 for WNV and in July 2003 for EEE. In 2004, the highest IgM seroconversions to EEE occurred later in August. The overall trend of arbovirus activity was greater in 2003 than in 2004. PMID:16696451

  18. Rodents as Sentinels for the Prevalence of Tick-Borne Encephalitis Virus

    PubMed Central

    Růžek, Daniel; Donoso-Mantke, Oliver; Schlegel, Mathias; Ali, Hanan Sheikh; Wenk, Mathias; Schmidt-Chanasit, Jonas; Ohlmeyer, Lutz; Rühe, Ferdinand; Vor, Torsten; Kiffner, Christian; Kallies, René; Ulrich, Rainer G.; Niedrig, Matthias

    2011-01-01

    Abstract Introduction Tick-borne encephalitis virus (TBEV) causes one of the most important flavivirus infections of the central nervous system, affecting humans in Europe and Asia. It is mainly transmitted by the bite of an infected tick and circulates among them and their vertebrate hosts. Until now, TBE risk analysis in Germany has been based on the incidence of human cases. Because of an increasing vaccination rate, this approach might be misleading, especially in regions of low virus circulation. Method To test the suitability of rodents as a surrogate marker for virus spread, laboratory-bred Microtus arvalis voles were experimentally infected with TBEV and analyzed over a period of 100 days by real-time (RT)–quantitative polymerase chain reaction. Further, the prevalence of TBEV in rodents trapped in Brandenburg, a rural federal state in northeastern Germany with autochthonous TBE cases, was determined and compared with that in rodents from German TBE risk areas as well as TBE nonrisk areas. Results In experimentally infected M. arvalis voles, TBEV was detectable in different organs for at least 3 months and in blood for 1 month. Ten percent of all rodents investigated were positive for TBEV. However, in TBE risk areas, the infection rate was higher compared with that of areas with only single human cases or of nonrisk areas. TBEV was detected in six rodent species: Apodemus agrarius, Apodemus flavicollis, Apodemus sylvaticus, Microtus agrestis, Microtus arvalis, and Myodes glareolus. M. glareolus showed a high infection rate in all areas investigated. Discussion and Conclusion The infection experiments proved that TBEV can be reliably detected in infected M. arvalis voles. These voles developed a persistent TBE infection without clinical symptoms. Further, the study showed that rodents, especially M. glareolus, are promising sentinels particularly in areas of low TBEV circulation. PMID:21548766

  19. Human arboviral encephalitis.

    PubMed

    Rust, Robert S

    2012-09-01

    Worldwide, arboviral illnesses constitute the most important international infectious threat to human neurological health and welfare. Before the availability of effective immunizations, approximately 50,000 cases of Japanese encephalitis occurred in the world each year, one-fifth of which cases proved lethal and a much larger number were left with severe neurological handicaps. With global climate change and perhaps other factors, the prevalences of some arboviral illnesses appear to be increasing. Arboviral illnesses, including Japanese encephalitis, tick-borne encephalitis, Yellow fever, and others, are emerging as possible global health care threats because of biological warfare. This chapter will review ecology, pathophysiology, diagnosis, management, and outcome of the forms of arboviral encephalitis that are of greatest importance in North America, together with some of the most important arboviral encephalitides prevalent in other parts of the world. PMID:22889543

  20. Evaluation of a Caprine Arthritis-Encephalitis Virus/Maedi-Visna Virus Indirect Enzyme-Linked Immunosorbent Assay in the Serological Diagnosis of Ovine Progressive Pneumonia Virus in U.S. Sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Serological diagnostic testing of sheep and goats using enzyme immunosorbent assays (ELISAs) is the most common method of determining small ruminant lentivirus (SRLV) infection. A caprine arthritis-encephalitis virus (CAEV)/maedi-visna virus (MVV) indirect (i) ELISA, which utilizes MVV EV1 capsid a...

  1. Host Range of Small-Ruminant Lentivirus Cytopathic Variants Determined with a Selectable Caprine Arthritis- Encephalitis Virus Pseudotype System

    PubMed Central

    Hötzel, Isidro; Cheevers, William P.

    2001-01-01

    The small-ruminant lentiviruses ovine maedi-visna virus (MVV) and caprine arthritis-encephalitis virus (CAEV) cause encephalitis, progressive pneumonia, arthritis, and mastitis in sheep and goats. Icelandic MVV strains, which are lytic in tissue culture, have a wide species distribution of functional receptors, which includes human cells. In contrast, functional receptors for the nonlytic CAEV CO are absent from human cells. To determine if the wide species distribution of functional receptors is a common property of MVV strains or related to cytopathic phenotype, we tested the infectivity of viruses pseudotyped with the envelope glycoproteins of MVV K1514, CAEV CO, and lytic and nonlytic North American MVV strains to cells of different species. Replication-defective CAEV proviral constructs lacking the env, tat, and vif genes and carrying the neomycin phosphotransferase gene in the vif-tat region were developed for the infectivity assays. Cotransfection of human 293T cells with these proviral constructs and plasmids expressing CAEV, MVV, or vesicular stomatitis virus envelope glycoproteins produced infectious pseudotyped virus which induced resistance of infected cells to G418. Using these pseudotypes, we confirmed the wide species distribution of Icelandic MVV receptors and the narrow host range of CAEV. However, functional receptors for the two North American MVV strains tested, unlike the Icelandic MVV and similar to CAEV, were limited to cells of ruminant species, regardless of cytopathic phenotype. The results indicate a differential receptor recognition by MVV strains which is unrelated to cytopathic phenotype. PMID:11462010

  2. Pathologic Potential of Variant Clones of the Oshima Strain of Far-Eastern Subtype Tick-Borne Encephalitis Virus

    PubMed Central

    Luat, Le Xuan; Tun, Mya Myat Ngwe; Buerano, Corazon C.; Aoki, Kotaro; Morita, Kouichi; Hayasaka, Daisuke

    2014-01-01

    Tick-borne encephalitis virus (TBEV) is a zoonotic agent that causes acute central nervous system (CNS) disease in humans. We previously suggested that immune response in addition to CNS infection contribute to mouse mortality following TBEV infection. However, we did not examine the influence of virus variants in the previous study. Therefore, in this study, we investigated the biological and pathologic potentials of the variant clones in the TBEV Oshima strain. We isolated eight variant clones from the stock virus of the Oshima 5-10. These variants exhibited different plaque morphologies in BHK cells and pathogenic potentials in mice. Full sequences of viral genomes revealed that each of the variant clones except one had specific combinations of nucleotide and amino acid changes at certain positions different from the parent strain. We also showed that an amino acid substitution of Glu122→Gly in the E protein could have affected virus infection and replication in vivo, as well as the attenuated pathogenicity in mice. These data confirm the presence of virus variants or quasispecies from the parent strain. Further elucidation of the effect of each variant clone on immune responses such as the T-cell response is an important priority in the development of an effective vaccine and treatment strategies for tick-borne encephalitis. PMID:24808743

  3. Evolutionary genetics and vector adaptation of recombinant viruses of the western equine encephalitis antigenic complex provides new insights into alphavirus diversity and host switching

    PubMed Central

    Allison, Andrew B.; Stallknecht, David E.; Holmes, Edward C.

    2014-01-01

    Western equine encephalitis virus (WEEV), Highlands J virus (HJV), and Fort Morgan virus (FMV) are the sole representatives of the WEE antigenic complex of the genus Alphavirus, family Togaviridae, that are endemic to North America. All three viruses have their ancestry in a recombination event involving eastern equine encephalitis virus (EEEV) and a Sindbis (SIN)-like virus that gave rise to a chimeric alphavirus that subsequently diversified into the present-day WEEV, HJV, and FMV. Here, we present a comparative analysis of the genetic, ecological, and evolutionary relationships among these recombinant-origin viruses, including the description of a nsP4 polymerase mutation in FMV that allows it to circumvent the host range barrier to Asian tiger mosquito cells, a vector species that is normally refractory to infection. Notably, we also provide evidence that the recombination event that gave rise to these three WEEV antigenic complex viruses may have occurred in North America. PMID:25463613

  4. The Immune Response to Herpes Simplex Virus Encephalitis in Mice Is Modulated by Dietary Vitamin E12

    PubMed Central

    Sheridan, Patricia A.; Beck, Melinda A.

    2008-01-01

    Herpes simplex virus encephalitis (HSE) is the most common fatal sporadic encephalitis in humans. HSE is primarily caused by herpes simplex virus (HSV)-1 infection of the brain. HSE results in increased levels of oxidative stress, including the production of reactive oxygen species, free radicals, and neuroinflammation. The most biologically active form of vitamin E (VE) is α-tocopherol (α-TOC). In cellular membranes, α-TOC prevents lipid peroxidation by scavenging free radicals and functioning as an antioxidant. Supplementation with VE has been shown to decrease immunosenescence, improve immune function, and may be neuroprotective. To determine how VE deficiency and VE supplementation would alter the pathogenesis of HSE, we placed weanling male BALB/cByJ mice on VE-deficient (VE-D), VE-adequate (VE-A), or 10× VE-supplemented diets for 4 wk, and then infected the mice intranasally with HSV-1. VE-D mice had more severe symptoms of encephalitis than VE-A mice, including weight loss, keratitis, hunched posture, and morbidity. VE-D mice had increased cytokine and chemokine expression in the brain and increased viral titers. In contrast, VE supplementation failed to decrease cytokine production and had no effect on viral titer. We demonstrated that adequate levels of VE are important in limiting HSE pathology and that 10× supplementation does not enhance protection. PMID:18156415

  5. Human pegivirus detected in a patient with severe encephalitis using a metagenomic pan-virus array.

    PubMed

    Fridholm, Helena; Østergaard Sørensen, Line; Rosenstierne, Maiken W; Nielsen, Henrik; Sellebjerg, Finn; Bengård Andersen, Åse; Fomsgaard, Anders

    2016-04-01

    We have used a metagenomic microarray to detect genomic RNA from human pegivirus in serum and cerebrospinal fluid from a patient suffering from severe encephalitis. No other pathogen was detected. HPgV in cerebrospinal fluid during encephalitis has never been reported before and its prevalence in cerebrospinal fluid needs further investigation. PMID:26872326

  6. Antibody response of sandhill and whooping cranes to an eastern equine encephalitis virus vaccine

    USGS Publications Warehouse

    Clark, G.G.; Dein, F.J.; Crabbs, C.L.; Carpenter, J.W.; Watts, D.M.

    1987-01-01

    As a possible strategy to protect whooping cranes (Grus americana) from fatal eastern equine encephalitis (EEE) viral infection, studies were conducted to determine the immune response of this species and sandhill cranes (Grus canadensis) to a formalin-inactivated EEE viral vaccine. Viral-specific neutralizing antibody was elicited in both species after intramuscular (IM) vaccination. Subcutaneous and intravenous routes of vaccination failed to elicit detectable antibody in sandhill cranes. Among the IM vaccinated cranes, the immune response was characterized by nondetectable or low antibody titers that waned rapidly following primary exposure to the vaccine. However, one or more booster doses consistently elicited detectable antibody and/or increased antibody titers in the whooping cranes. In contrast, cranes with pre-existing EEE viral antibody, apparently induced by natural infection, exhibited a rapid increase and sustained high-antibody titers. Even though EEE virus vaccine induced neutralizing antibody and produced no adverse side effects, further studies will be required to determine the protective efficacy of the antibody.

  7. Venezuelan Equine Encephalitis Virus in Iquitos, Peru: Urban Transmission of a Sylvatic Strain

    PubMed Central

    Morrison, Amy C.; Forshey, Brett M.; Notyce, Desiree; Astete, Helvio; Lopez, Victor; Rocha, Claudio; Carrion, Rebecca; Carey, Cristhiam; Eza, Dominique; Montgomery, Joel M.; Kochel, Tadeusz J.

    2008-01-01

    Enzootic strains of Venezuelan equine encephalitis virus (VEEV) have been isolated from febrile patients in the Peruvian Amazon Basin at low but consistent levels since the early 1990s. Through a clinic-based febrile surveillance program, we detected an outbreak of VEEV infections in Iquitos, Peru, in the first half of 2006. The majority of these patients resided within urban areas of Iquitos, with no report of recent travel outside the city. To characterize the risk factors for VEEV infection within the city, an antibody prevalence study was carried out in a geographically stratified sample of urban areas of Iquitos. Additionally, entomological surveys were conducted to determine if previously incriminated vectors of enzootic VEEV were present within the city. We found that greater than 23% of Iquitos residents carried neutralizing antibodies against VEEV, with significant associations between increased antibody prevalence and age, occupation, mosquito net use, and overnight travel. Furthermore, potential vector mosquitoes were widely distributed across the city. Our results suggest that while VEEV infection is more common in rural areas, transmission also occurs within urban areas of Iquitos, and that further studies are warranted to identify the precise vectors and reservoirs involved in urban VEEV transmission. PMID:19079600

  8. Tick-Borne Encephalitis Virus Infects Rat Astrocytes but Does Not Affect Their Viability

    PubMed Central

    Potokar, Maja; Korva, Miša; Jorgačevski, Jernej; Avšič-Županc, Tatjana; Zorec, Robert

    2014-01-01

    Tick-borne encephalitis virus (TBEV) causes one of the most dangerous human neuroinfections in Europe and Asia. To infect neurons it must cross the blood-brain-barrier (BBB), and presumably also cells adjacent to the BBB, such as astrocytes, the most abundant glial cell type. However, the knowledge about the viral infection of glial cells is fragmental. Here we studied whether TBEV infects rat astrocytes. Rats belong to an animal group serving as a TBEV amplifying host. We employed high resolution quantitative fluorescence microscopy to investigate cell entry and cytoplasmic mobility of TBEV particles along with the effect on the cell cytoskeleton and cell survival. We report that infection of astrocytes with TBEV increases with time of exposure to TBEV and that with post-infection time TBEV particles gained higher mobility. After several days of infection actin cytoskeleton was affected, but cell survival was unchanged, indicating that rat astrocytes resist TBEV-mediated cell death, as reported for other mammalian cells. Therefore, astrocytes may present an important pool of dormant TBEV infections and a new target for therapeutic intervention. PMID:24465969

  9. Origin of the West Nile virus responsible for an outbreak of encephalitis in the northeastern United States.

    PubMed

    Lanciotti, R S; Roehrig, J T; Deubel, V; Smith, J; Parker, M; Steele, K; Crise, B; Volpe, K E; Crabtree, M B; Scherret, J H; Hall, R A; MacKenzie, J S; Cropp, C B; Panigrahy, B; Ostlund, E; Schmitt, B; Malkinson, M; Banet, C; Weissman, J; Komar, N; Savage, H M; Stone, W; McNamara, T; Gubler, D J

    1999-12-17

    In late summer 1999, an outbreak of human encephalitis occurred in the northeastern United States that was concurrent with extensive mortality in crows (Corvus species) as well as the deaths of several exotic birds at a zoological park in the same area. Complete genome sequencing of a flavivirus isolated from the brain of a dead Chilean flamingo (Phoenicopterus chilensis), together with partial sequence analysis of envelope glycoprotein (E-glycoprotein) genes amplified from several other species including mosquitoes and two fatal human cases, revealed that West Nile (WN) virus circulated in natural transmission cycles and was responsible for the human disease. Antigenic mapping with E-glycoprotein-specific monoclonal antibodies and E-glycoprotein phylogenetic analysis confirmed these viruses as WN. This North American WN virus was most closely related to a WN virus isolated from a dead goose in Israel in 1998. PMID:10600742

  10. Environmental and Biological Factors Influencing Culex pipiens quinquefasciatus Say (Diptera: Culicidae) Vector Competence for Saint Louis Encephalitis Virus

    PubMed Central

    Richards, Stephanie L.; Lord, Cynthia C.; Pesko, Kendra; Tabachnick, Walter J.

    2009-01-01

    Complex interactions between environmental and biological factors influence the susceptibility of Culex pipiens quinquefasciatus to St. Louis encephalitis virus and could affect the epidemiology of virus transmission. Similar interactions could have epidemiologic implications for other vector-virus systems. We conducted an experiment to examine four such factors in combination: mosquito age, extrinsic incubation temperature (EIT), virus dose, and colony. The proportion of mosquitoes with body infections or disseminated infections varied between colonies, and was dependant on age, EIT, and dose. We also show that the probability of a body or leg infection interacted in complex ways between colonies, ages, EITs, and doses. The complex interactive effects of environmental and biological factors must be taken into account for studies of vector competence and epidemiology, especially when laboratory studies are used to generalize to natural transmission dynamics where the extent of variation is largely unknown. PMID:19635881

  11. INDUCTION OF NEUTRALIZING ANTIBODIES TO HENDRA AND NIPAH GLYCOPROTEINS USING A VENEZUELAN EQUINE ENCEPHALITIS VIRUS IN VIVO EXPESSION SYSTEM

    PubMed Central

    Defang, Gabriel N.; Khetawat, Dimple; Broder, Christopher C.; Quinnan, Gerald V.

    2010-01-01

    The emergence of Hendra Virus (HeV) and Nipah Virus (NiV) which can cause fatal infections in both animals and humans has triggered a search for an effective vaccine. Here, we have explored the potential for generating an effective humoral immune response to these zoonotic pathogens using an alphavirus-based vaccine platform. Groups of mice were immunized with Venezuelan equine encephalitis virus replicon particles (VRP) encoding the attachment or fusion glycoproteins of either HeV or NiV. We demonstrate the induction of highly potent cross-reactive neutralizing antibodies to both viruses using this approach. Preliminary study suggested early enhancement in the antibody response with use of a modified version of VRP. Overall, these data suggest that the use of an alphavirus-derived vaccine platform might serve as a viable approach for development of an effective vaccine against the henipaviruses. PMID:21050901

  12. Maedi-Visna Virus and Caprine Arthritis Encephalitis Virus Genomes Encode a Vpr-Like but No Tat Protein

    PubMed Central

    Villet, Stéphanie; Bouzar, Baya Amel; Morin, Thierry; Verdier, Gérard; Legras, Catherine; Chebloune, Yahia

    2003-01-01

    A small open reading frame (ORF) in maedi-visna virus (MVV) and caprine arthritis encephalitis virus (CAEV) was initially named “tat” by analogy with a similarly placed ORF in the primate lentiviruses. The encoded “Tat” protein was ascribed the function of up regulation of the viral transcription from the long terminal repeat (LTR) promoter, but we have recently reported that MVV and CAEV Tat proteins lack trans-activation function activity under physiological conditions (S. Villet, C. Faure, B. Bouzar, G. Verdien, Y. Chebloune, and C. Legras, Virology 307:317-327, 2003). In the present work, we show that MVV Tat localizes to the nucleus of transfected cells, probably through the action of a nuclear localization signal in its C-terminal portion. We also show that, unlike the human immunodeficiency virus (HIV) Tat protein, MVV Tat was not secreted into the medium by transfected human or caprine cells in the absence of cell lysis but that, like the primate accessory protein Vpr, MVV and CAEV Tat proteins were incorporated into viral particles. In addition, analysis of the primary protein structures showed that small-ruminant lentivirus (SRLV) Tat proteins are more similar to the HIV type 1 (HIV-1) Vpr protein than to HIV-1 Tat. We also demonstrate a functional similarity between the SRLV Tat proteins and the HIV-1 Vpr product in the induction of a specific G2 arrest of the cell cycle in MVV Tat-transfected cells, which increases the G2/G1 ratio 2.8-fold. Together, these data strongly suggest that the tat ORF in the SRLV genomes does not code for a regulatory transactivator of the LTR but, rather, for a Vpr-like accessory protein. PMID:12915575

  13. Eastern Equine Encephalitis

    MedlinePlus

    ... Facebook Tweet Share Compartir Image of Culiseta melanura mosquito, photo taken by Jason Williams, reproduced by permission from the Virginia Mosquito Control Association. Eastern equine encephalitis virus (EEEV) is ...

  14. Susceptibility to measles virus-induced encephalitis in mice correlates with impaired antigen presentation to cytotoxic T lymphocytes.

    PubMed Central

    Niewiesk, S; Brinckmann, U; Bankamp, B; Sirak, S; Liebert, U G; ter Meulen, V

    1993-01-01

    In measles virus (MV) infection in humans, meningitis and encephalitis are important complications. However, little is known of the pathogenesis of MV encephalitis, in particular about the role of the immune response. We have examined the role of cytotoxic T lymphocytes (CTL) in a mouse model of MV-induced encephalitis. We report here that the resistance of inbred strains of mice to MV-induced encephalitis correlated with the major histocompatibility complex (MHC) haplotype and that only resistant mouse strains mounted an effective CTL response to MV. Mice with low susceptibility to MV infection, such as the BALB/c strain (H-2d), generated CTL, whereas the highly susceptible strains, C3H (H-2k) and C57BL/6 (H-2b), revealed very poor CTL responses. MV-induced CTL were usually CD8+, and the generation of these cells was independent of the route of inoculation or the time postinfection. CD4+ T cells were generally only weakly lytic. The nucleocapsid protein was the major target antigen for CTL in BALB/c mice, although in some experiments the hemagglutinin was also recognized. CTL from C3H and C57BL/6 mice did not lyse MV-infected target cells. However, targets infected with vaccinia virus recombinants expressing the nucleocapsid protein or hemagglutinin were lysed, but levels of cytotoxicity were still low. Experiments using target cells transfected with single MHC class I genes suggested inefficient antigen presentation of MV proteins by the MHC molecules of the H-2k and H-2b haplotypes. PMID:8093223

  15. Emergence of CD4 Independence Envelopes and Astrocyte Infection in R5 Simian-Human Immunodeficiency Virus Model of Encephalitis

    PubMed Central

    Zhuang, Ke; Leda, Ana Rachel; Tsai, Lily; Knight, Heather; Harbison, Carole; Gettie, Agegnehu; Blanchard, James; Westmoreland, Susan

    2014-01-01

    ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection in the central nervous system (CNS) is characterized by replication in macrophages or brain microglia that express low levels of the CD4 receptor and is the cause of HIV-associated dementia and related cognitive and motor disorders that affect 20 to 30% of treatment-naive patients with AIDS. Independent viral envelope evolution in the brain has been reported, with the need for robust replication in resident CD4low cells, as well as CD4-negative cells, such as astrocytes, proposed as a major selective pressure. We previously reported giant-cell encephalitis in subtype B and C R5 simian-human immunodeficiency virus (SHIV)-infected macaques (SHIV-induced encephalitis [SHIVE]) that experienced very high chronic viral loads and progressed rapidly to AIDS, with varying degrees of macrophage or microglia infection and activation of these immune cells, as well as astrocytes, in the CNS. In this study, we characterized envelopes (Env) amplified from the brains of subtype B and C R5 SHIVE macaques. We obtained data in support of an association between severe neuropathological changes, robust macrophage and microglia infection, and evolution to CD4 independence. Moreover, the degree of Env CD4 independence appeared to correlate with the extent of astrocyte infection in vivo. These findings further our knowledge of the CNS viral population phenotypes that are associated with the severity of HIV/SHIV-induced neurological injury and improve our understanding of the mechanism of HIV-1 cellular tropism and persistence in the brain. IMPORTANCE Human immunodeficiency virus type 1 (HIV-1) infection of astrocytes in the brain has been suggested to be important in HIV persistence and neuropathogenesis but has not been definitively demonstrated in an animal model of HIV-induced encephalitis (HIVE). Here, we describe a new nonhuman primate (NHP) model of R5 simian-human immunodeficiency virus (SHIV)-induced encephalitis

  16. Kinetic, Mutational, and Structural Studies of the Venezuelan Equine Encephalitis Virus Nonstructural Protein 2 Cysteine Protease.

    PubMed

    Hu, Xin; Compton, Jaimee R; Leary, Dagmar H; Olson, Mark A; Lee, Michael S; Cheung, Jonah; Ye, Wenjuan; Ferrer, Mark; Southall, Noel; Jadhav, Ajit; Morazzani, Elaine M; Glass, Pamela J; Marugan, Juan; Legler, Patricia M

    2016-05-31

    The Venezuelan equine encephalitis virus (VEEV) nonstructural protein 2 (nsP2) cysteine protease (EC 3.4.22.-) is essential for viral replication and is involved in the cytopathic effects (CPE) of the virus. The VEEV nsP2 protease is a member of MEROPS Clan CN and characteristically contains a papain-like protease linked to an S-adenosyl-l-methionine-dependent RNA methyltransferase (SAM MTase) domain. The protease contains an alternative active site motif, (475)NVCWAK(480), which differs from papain's (CGS(25)CWAFS), and the enzyme lacks a transition state-stabilizing residue homologous to Gln-19 in papain. To understand the roles of conserved residues in catalysis, we determined the structure of the free enzyme and the first structure of an inhibitor-bound alphaviral protease. The peptide-like E64d inhibitor was found to bind beneath a β-hairpin at the interface of the SAM MTase and protease domains. His-546 adopted a conformation that differed from that found in the free enzyme; one or both of the conformers may assist in leaving group departure of either the amine or Cys thiolate during the catalytic cycle. Interestingly, E64c (200 μM), the carboxylic acid form of the E64d ester, did not inhibit the nsP2 protease. To identify key residues involved in substrate binding, a number of mutants were analyzed. Mutation of the motif residue, N475A, led to a 24-fold reduction in kcat/Km, and the conformation of this residue did not change after inhibition. N475 forms a hydrogen bond with R662 in the SAM MTase domain, and the R662A and R662K mutations both led to 16-fold decreases in kcat/Km. N475 forms the base of the P1 binding site and likely orients the substrate for nucleophilic attack or plays a role in product release. An Asn homologous to N475 is similarly found in coronaviral papain-like proteases (PLpro) of the Severe Acute Respiratory Syndrome (SARS) virus and Middle East Respiratory Syndrome (MERS) virus. Mutation of another motif residue, K480A, led to a 9

  17. [Characteristics of tick-borne encephalitis virus strains isolated from patients with chronic diseases of the central nervous system].

    PubMed

    Pogodina, V V; Meĭerova, R A; Bochkova, N G; Koreshkova, G V

    1985-01-01

    Two groups of tick-borne encephalitis (TBE) virus strains were studied: Group 1, 5 strains isolated from patients with chronic TBE with progressive course, Group 2, 13 strains isolated from residents of an endemic locality, with chronic diseases of the CNS (amiotrophic lateral sclerosis, epidemic encephalitis, polyoencephalomyelitis, syringomyelia, etc.). Strains of both groups belong to two serotypes of TBE virus: mid-Siberian and Transbaikal (synonym Aina/1448) and eastern. Group 1 strains were heterogeneous in their virulence, immunogenic and surface properties of the virions. The latter characteristic was demonstrated in studies of elution from macropore glass and sensitivity of hemagglutinin to the effect of detergents (Bridge-96, Tween-80). Eight of 13 Group 2 patients had concurrent diseases (tuberculosis, toxoplasmosis, tumors, etc.). Streptomycin was demonstrated to activate asymptomatic infection with TBE virus in hamsters. It is assumed that isolation of TBE virus from Group 2 patients could be due to activation of persistent infection under the effect of concurrent diseases and drugs. PMID:4060699

  18. Travelers' Health: Japanese Encephalitis

    MedlinePlus

    ... Global TravEpiNet Mobile Apps RSS Feeds Chapter 3 Infectious Diseases Related to Travel Recommend on Facebook Tweet Share ... and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of Global Migration and Quarantine (DGMQ) ...

  19. Survey for Hantaviruses, Tick-Borne Encephalitis Virus, and Rickettsia spp. in Small Rodents in Croatia

    PubMed Central

    Dobler, Gerhard; Markotić, Alemka; Kurolt, Ivan-Christian; Speck, Stephanie; Habuš, Josipa; Vucelja, Marko; Krajinović, Lidija Cvetko; Tadin, Ante; Margaletić, Josip; Essbauer, Sandra

    2014-01-01

    Abstract In Croatia, several rodent- and vector-borne agents are endemic and of medical importance. In this study, we investigated hantaviruses and, for the first time, tick-borne encephalitis virus (TBEV) and Rickettsia spp. in small wild rodents from two different sites (mountainous and lowland region) in Croatia. In total, 194 transudate and tissue samples from 170 rodents (A. flavicollis, n=115; A. agrarius, n=2; Myodes glareolus, n=53) were tested for antibodies by indirect immunoflourescence assays (IIFT) and for nucleic acids by conventional (hantaviruses) and real-time RT-/PCRs (TBEV and Rickettsia spp.). A total of 25.5% (24/94) of the rodents from the mountainous area revealed specific antibodies against hantaviruses. In all, 21.3% (20/94) of the samples from the mountainous area and 29.0% (9/31) from the lowland area yielded positive results for either Puumala virus (PUUV) or Dobrava–Belgrade virus (DOBV) using a conventional RT-PCR. All processed samples (n=194) were negative for TBEV by IIFT or real-time RT-PCR. Serological evidence of rickettsial infection was detected in 4.3% (4/94) rodents from the mountainous region. Another 3.2% (3/94) rodents were positive for Rickettsia spp. by real-time PCR. None of the rodents (n=76) from the lowland area were positive for Rickettsia spp. by real-time PCR. Dual infection of PUUV and Rickettsia spp. was found in one M. glareolus from the mountainous area by RT-PCR and real-time PCR, respectively. To our knowledge, this is the first detection of Rickettsia spp. in small rodents from Croatia. Phylogenetic analyses of S- and M-segment sequences obtained from the two study sites revealed well-supported subgroups in Croatian PUUV and DOBV. Although somewhat limited, our data showed occurrence and prevalence of PUUV, DOBV, and rickettsiae in Croatia. Further studies are warranted to confirm these data and to determine the Rickettsia species present in rodents in these areas. PMID:24866325

  20. Potential role of deer tick virus in Powassan encephalitis cases in Lyme disease-endemic areas of New York, U.S.A.

    PubMed

    El Khoury, Marc Y; Camargo, Jose F; White, Jennifer L; Backenson, Bryon P; Dupuis, Alan P; Escuyer, Kay L; Kramer, Laura; St George, Kirsten; Chatterjee, Debarati; Prusinski, Melissa; Wormser, Gary P; Wong, Susan J

    2013-12-01

    Powassan virus, a member of the tick-borne encephalitis group of flaviviruses, encompasses 2 lineages with separate enzootic cycles. The prototype lineage of Powassan virus (POWV) is principally maintained between Ixodes cookei ticks and the groundhog (Marmota momax) or striped skunk (Mephitis mephitis), whereas the deer tick virus (DTV) lineage is believed to be maintained between Ixodes scapularis ticks and the white-footed mouse (Peromyscus leucopus). We report 14 cases of Powassan encephalitis from New York during 2004-2012. Ten (72%) of the patients were residents of the Lower Hudson Valley, a Lyme disease-endemic area in which I. scapularis ticks account for most human tick bites. This finding suggests that many of these cases were caused by DTV rather than POWV. In 2 patients, DTV infection was confirmed by genetic sequencing. As molecular testing becomes increasingly available, more cases of Powassan encephalitis may be determined to be attributable to the DTV lineage. PMID:24274334

  1. Estimation of the Impact of a Japanese Encephalitis Immunization Program with Live, Attenuated SA 14-14-2 Vaccine in Nepal

    PubMed Central

    Upreti, Shyam Raj; Janusz, Kristen B.; Schluter, W. William; Bichha, Ram Padarath; Shakya, Geeta; Biggerstaff, Brad J.; Shrestha, Murari Man; Sedai, Tika Ram; Fischer, Marc; Gibbons, Robert V.; Shrestha, Sanjaya K.; Hills, Susan L.

    2013-01-01

    Wider availability of the live, attenuated SA 14-14-2 Japanese encephalitis (JE) vaccine has facilitated introduction or expansion of immunization programs in many countries. However, information on their impact is limited. In 2006, Nepal launched a JE immunization program, and by 2009, mass campaigns had been implemented in 23 districts. To describe the impact, we analyzed surveillance data from 2004 to 2009 on laboratory-confirmed JE and clinical acute encephalitis syndrome (AES) cases. The post-campaign JE incidence rate of 1.3 per 100,000 population was 72% lower than expected if no campaigns had occurred, and an estimated 891 JE cases were prevented. In addition, AES incidence was 58% lower, with an estimated 2,787 AES cases prevented, suggesting that three times as many disease cases may have been prevented than indicated by the laboratory-confirmed JE cases alone. These results provide useful information on preventable JE disease burden and the potential value of JE immunization programs. PMID:23358643

  2. Using network analysis to explore if professional opinions on Japanese encephalitis risk factors in Nepal reflect a socio-ecological system perspective.

    PubMed

    Hecker, Kent; El Kurdi, Syliva; Joshi, Durgadatt; Stephen, Craig

    2013-12-01

    Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia and a significant public health problem in Nepal. Its epidemiology is influenced by factors affecting its amplifying hosts (pigs), vectors (mosquitoes), and dead-end hosts (including people). While most control efforts target reduced susceptibility to infection either by vaccination of people or pigs or by reduced exposure to mosquitoes; the economic reality of Nepal makes it challenging to implement standard JE control measures. An ecohealth approach has been nominated as a way to assist in finding and prioritizing locally relevant strategies for JE control that may be viable, feasible, and acceptable. We sought to understand if Nepalese experts responsible for JE management conceived of its epidemiology in terms of a socio-ecological system to determine if they would consider ecohealth approaches. Network analysis suggested that they did not conceive JE risk as a product of a socio-ecological system. Traditional proximal risk factors of pigs, mosquitoes, and vaccination predominated experts' conception of JE risk. People seeking to encourage an ecohealth approach or social change models to JE management in Nepal may benefit from adopting social marketing concepts to encourage and empower local experts to examine JE from a socio-ecological perspective. PMID:24052266

  3. [Encephalitis due to the Epstein-Barr virus: a description of a clinical case and review of the literature].

    PubMed

    Barón, Johanna; Herrero-Velázquez, Sonia; Ruiz-Piñero, Marina; Pedraza, M Isabel; Rojo-Rello, Silvia; Guerrero-Peral, Ángel Luis

    2013-11-16

    INTRODUCTION. Infection by the Epstein-Barr virus (EBV) -either as a primary infection, a reactivation or an active chronic infection- can give rise to several clinical forms of involvement of the central nervous system. We report a case of encephalitis due to EBV produced by viral reactivation in an immunocompetent patient which initially mimicked, from the clinical and electroencephalographic point of view, encephalitis due to type 1 herpes simplex virus (HSV-1). CASE REPORT. A 51-year-old male who had reported the presence of dorsal herpes zoster some days earlier. The patient visited the emergency department after suffering a holocranial oppressive headache and febricula for seven days; 24 hours before admission to hospital, he was suffering from drowsiness and language disorder. The neurological examination revealed stiffness in the back of the neck and dysphasia. An analysis of the cerebrospinal fluid revealed pleocytosis (422 cells/mm(3)) with 98% of mononuclear cells and normal protein and glucose concentration levels in cerebrospinal fluid. Magnetic resonance imaging of the brain and electroencephalogram readings were normal with periodic lateralised epileptiform discharges in the left temporal region. Intravenous acyclovir treatment was initiated, but renal failure meant it had to be changed to oral valaciclovir with clinical resolution and improvement of the liquoral parameters. Polymerase chain reaction in the cerebrospinal fluid was positive for EBV and negative for the other neurotropic viruses. In blood, the serology test for EBV with IgG was positive, while IgM and heterophile antibody tests were negative. CONCLUSIONS. EBV infection can give rise to acute disseminated encephalomyelitis or affect several locations in the central nervous system, especially the cerebellum. Clinical pictures mimicking HSV-1 are less frequent. When encephalitis is related to viral reactivation, precipitating factors can be detected, as in our case. PMID:24203667

  4. Fatal Caprine arthritis encephalitis virus-like infection in 4 Rocky Mountain goats (Oreamnos americanus).

    PubMed

    Patton, Kristin M; Bildfell, Robert J; Anderson, Mark L; Cebra, Christopher K; Valentine, Beth A

    2012-03-01

    Over a 3.5-year period, 4 Rocky Mountain goats (Oreamnos americanus), housed at a single facility, developed clinical disease attributed to infection by Caprine arthritis encephalitis virus (CAEV). Ages ranged from 1 to 10 years. Three of the goats, a 1-year-old female, a 2-year-old male, and a 5-year-old male, had been fed raw domestic goat milk from a single source that was later found to have CAEV on the premises. The fourth animal, a 10-year-old male, had not ingested domestic goat milk but had been housed with the other 3 Rocky Mountain goats. All 4 animals had clinical signs of pneumonia prior to death. At necropsy, findings in lungs included marked diffuse interstitial pneumonia characterized histologically by severe lymphoplasmacytic infiltrates with massive alveolar proteinosis, interstitial fibrosis, and type II pneumocyte hyperplasia. One animal also developed left-sided hemiparesis, and locally extensive lymphoplasmacytic myeloencephalitis was present in the cranial cervical spinal cord. Two animals had joint effusions, as well as severe lymphoplasmacytic and ulcerative synovitis. Immunohistochemical staining of fixed sections of lung tissue from all 4 goats, as well as spinal cord in 1 affected animal, and synovium from 2 affected animals were positive for CAEV antigen. Serology testing for anti-CAEV antibodies was positive in the 2 goats tested. The cases suggest that Rocky Mountain goats are susceptible to naturally occurring CAEV infection, that CAEV from domestic goats can be transmitted to this species through infected milk and by horizontal transmission, and that viral infection can result in clinically severe multisystemic disease. PMID:22379056

  5. Lack of usutu virus RNA in cerebrospinal fluid of patients with encephalitis of unknown etiology, Tuscany, Italy.

    PubMed

    Maggi, Fabrizio; Mazzetti, Paola; Focosi, Daniele; Macera, Lisa; Scagnolari, Carolina; Manzin, Aldo; Antonelli, Guido; Nelli, Luca Ceccherini

    2015-06-01

    Usutu virus (USUV) is an African mosquito-borne flavivirus associated with human neurological disorders in Europe. Recently, USUV introduction in Europe has been traced back to Eurasian blackbirds deaths in the Tuscany region of Italy in 1996. Ninety-six cerebrospinal fluid (CSF) samples from patients with encephalitis of unknown etiology diagnosed in 2010-2013 were screened to determine whether USUV circulates in humans in Tuscany. Using real-time polymerase chain reaction, no positive patient was found. USUV does not seem to cause neuroinvasive disorders in humans in Tuscany. PMID:25712912

  6. The First Outbreak of Eastern Equine Encephalitis in Vermont: Outbreak Description and Phylogenetic Relationships of the Virus Isolate

    PubMed Central

    Saxton-Shaw, Kali D.; Ledermann, Jeremy P.; Kenney, Joan L.; Berl, Erica; Graham, Alan C.; Russo, Joel M.; Powers, Ann M.; Mutebi, John-Paul

    2015-01-01

    The first known outbreak of eastern equine encephalitis (EEE) in Vermont occurred on an emu farm in Rutland County in 2011. The first isolation of EEE virus (EEEV) in Vermont (VT11) was during this outbreak. Phylogenetic analysis revealed that VT11 was most closely related to FL01, a strain from Florida isolated in 2001, which is both geographically and temporally distinct from VT11. EEEV RNA was not detected in any of the 3,905 mosquito specimens tested, and the specific vectors associated with this outbreak are undetermined. PMID:26043136

  7. Immunization of mice with recombinant vaccinia virus expressing authentic dengue virus nonstructural protein NS1 protects against lethal dengue virus encephalitis.

    PubMed Central

    Falgout, B; Bray, M; Schlesinger, J J; Lai, C J

    1990-01-01

    The protective immunity conferred by a set of recombinant vaccinia viruses containing the entire coding sequence of dengue virus type 4 nonstructural glycoprotein NS1 plus various flanking sequences was evaluated by using a mouse encephalitis model. Mice immunized with recombinant vNS1-NS2a, which expresses authentic NS1, were solidly protected against intracerebral dengue virus challenge. However, mice immunized with recombinants vNS1-15%NS2a and vRSVG/NS1-15%NS2a, which express aberrant forms of NS1, were only partially protected (63 to 67% survival rate). Serologic analysis showed that mice immunized with vNS1-NS2a developed high titers of antibodies to NS1 as measured by radioimmunoprecipitation, enzyme-linked immunosorbent assay, and complement-mediated cytolytic assays. In addition, a pool of sera from these animals was protective in a passive transfer experiment. Lower titers of NS1-specific antibodies were detected in sera of animals immunized with vNS1-15%NS2a or vRSVG/NS1-15%NS2a by all three assays. These data support the view that protection against dengue virus infection in mice may be mediated at least in part by NS1-specific antibodies through a mechanism of complement-mediated lysis of infected cells. Additionally, immunization with two recombinant viruses expressing authentic NS1 of dengue virus type 2 conferred partial protection (30-50%) against dengue virus type 2 challenge. Images PMID:2143542

  8. The Type I Interferon Response Determines Differences in Choroid Plexus Susceptibility between Newborns and Adults in Herpes Simplex Virus Encephalitis

    PubMed Central

    Wilcox, Douglas R.; Folmsbee, Stephen S.; Muller, William J.

    2016-01-01

    ABSTRACT Newborns are significantly more susceptible to severe viral encephalitis than adults, with differences in the host response to infection implicated as a major factor. However, the specific host signaling pathways responsible for differences in susceptibility and neurologic morbidity have remained unknown. In a murine model of HSV encephalitis, we demonstrated that the choroid plexus (CP) is susceptible to herpes simplex virus 1 (HSV-1) early in infection of the newborn but not the adult brain. We confirmed susceptibility of the CP to HSV infection in a human case of newborn HSV encephalitis. We investigated components of the type I interferon (IFN) response in the murine brain that might account for differences in cell susceptibility and found that newborns have a dampened interferon response and significantly lower basal levels of the alpha/beta interferon (IFN-α/β) receptor (IFNAR) than do adults. To test the contribution of IFNAR to restricting infection from the CP, we infected IFNAR knockout (KO) adult mice, which showed restored CP susceptibility to HSV-1 infection in the adult. Furthermore, reduced IFNAR levels did not account for differences we found in the basal levels of several other innate signaling proteins in the wild-type newborn and the adult, including protein kinase R (PKR), that suggested specific regulation of innate immunity in the developing brain. Viral targeting of the CP, a region of the brain that plays a critical role in neurodevelopment, provides a link between newborn susceptibility to HSV and long-term neurologic morbidity among survivors of newborn HSV encephalitis. PMID:27073094

  9. The Bacteriostatic Protein Lipocalin 2 Is Induced in the Central Nervous System of Mice with West Nile Virus Encephalitis

    PubMed Central

    Noçon, Aline L.; Ip, Jacque P. K.; Terry, Rachael; Lim, Sue Ling; Getts, Daniel R.; Müller, Marcus; Hofer, Markus J.; King, Nicholas J. C.

    2014-01-01

    Lipocalin 2 (Lcn2) is a bacteriostatic factor produced during the innate immune response to bacterial infection. Whether Lcn2 has a function in viral infection is unknown. We investigated the regulation and function of Lcn2 in the central nervous system (CNS) of mice during West Nile virus (WNV) encephalitis. Lcn2 mRNA and protein were induced in the brain by day 5, and this induction increased further by day 7 postinfection but was delayed compared with the induction of the toll-like receptor 3 (TLR3) gene, retinoic acid-inducible gene 1 (RIG-I), and melanoma differentiation-associated protein 5 (MDA5) gene. The Lcn2 mRNA and protein were both found at high levels in the choroid plexus, vascular endothelium, macrophage/microglia, and astrocytes. However, some neuronal subsets contained Lcn2 protein but no detectable mRNA. In Lcn2 knockout (KO) mice, with the exception of CXC motif chemokine 5 (CXCL5), which was significantly more downregulated than in wild-type (WT) mice, expression levels of a number of other host response genes were similar in the two genotypes. The brain from Lcn2 and WT mice with WNV encephalitis contained similar numbers of infiltrating macrophages, granulocytes, and T cells. Lcn2 KO and WT mice had no significant difference in tissue viral loads or survival after infection with different doses of WNV. We conclude that Lcn2 gene expression is induced to high levels in a time-dependent fashion in a variety of cells and regions of the CNS of mice with WNV encephalitis. The function of Lcn2 in the host response to WNV infection remains largely unknown, but our data indicate that it is dispensable as an antiviral or immunoregulatory factor in WNV encephalitis. PMID:24173226

  10. Infection of neurons and encephalitis after intracranial inoculation of herpes simplex virus requires the entry receptor nectin-1

    PubMed Central

    Kopp, Sarah J.; Banisadr, Ghazal; Glajch, Kelly; Maurer, Ulrike E.; Grünewald, Kay; Miller, Richard J.; Osten, Pavel; Spear, Patricia G.

    2009-01-01

    Multiple entry receptors can mediate infection of cells by herpes simplex virus (HSV), permitting alternative pathways for infection and disease. We investigated the roles of two known entry receptors, herpesvirus entry mediator (HVEM) and nectin-1, in infection of neurons in the CNS and the development of encephalitis. Wild-type, HVEM KO, nectin-1 KO, and HVEM/nectin-1 double KO mice were inoculated with HSV into the hippocampus. The mice were examined for development of encephalitis or were killed at various times after inoculation for immunohistological analyses of brain slices. Nectin-1 KO mice showed no signs of disease after intracranial inoculation, and no HSV antigens were detectable in the brain parenchyma. However, HSV antigens were detected in non-parenchymal cells lining the ventricles. In the double KO mice, there was also no disease and no detectable expression of viral antigens even in non-parenchymal cells, indicating that infection of these cells in the nectin-1 KO mice was dependent on the expression of HVEM. Wild-type and HVEM KO mice rapidly developed encephalitis, and the patterns of HSV replication in the brain were indistinguishable. Thus, expression of nectin-1 is necessary for HSV infection via the intracranial route and for encephalitis; HVEM is largely irrelevant. These results contrast with recent findings that (i) either HVEM or nectin-1 can permit HSV infection of the vaginal epithelium in mice and (ii) nectin-1 is not the sole receptor capable of enabling spread of HSV infection from the vaginal epithelium to the PNS and CNS. PMID:19805039

  11. Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina.

    PubMed

    Diaz, Luis Adrián; Quaglia, Agustín Ignacio; Konigheim, Brenda Salomé; Boris, Analia Silvana; Aguilar, Juan Javier; Komar, Nicholas; Contigiani, Marta Silvia

    2016-01-01

    St. Louis encephalitis virus (SLEV) (Flavivirus) is a reemerging arbovirus in the southern cone of South America. In 2005, an outbreak of SLEV in central Argentina resulted in 47 human cases with 9 deaths. In Argentina, the ecology of SLEV is poorly understood. Because certain birds are the primary amplifiers in North America, we hypothesized that birds amplify SLEV in Argentina as well. We compared avian SLEV seroprevalence in a variety of ecosystems in and around Córdoba city from 2004 (before the epidemic) and 2005 (during the epidemic). We also explored spatial patterns to better understand the local ecology of SLEV transmission. Because West Nile virus (WNV) was also detected in Argentina in 2005, all analyses were also conducted for WNV. A total of 980 birds were sampled for detection of SLEV and WNV neutralizing antibodies. SLEV seroprevalence in birds increased 11-fold from 2004 to 2005. Our study demonstrated that a high proportion (99.3%) of local birds were susceptible to SLEV infection immediately prior to the 2005 outbreak, indicating that the vertebrate host population was primed to amplify SLEV. SLEV was found distributed in a variety of environments throughout the city of Córdoba. However, the force of viral transmission varied among sites. Fine scale differences in populations of vectors and vertebrate hosts would explain this variation. In summary, we showed that in 2005, both SLEV and to a lesser extent WNV circulated in the avian population. Eared Dove, Picui Ground-Dove and Great Kiskadee are strong candidates to amplify SLEV because of their exposure to the pathogen at the population level, and their widespread abundance. For the same reasons, Rufous Hornero may be an important maintenance host for WNV in central Argentina. Competence studies and vector feeding studies are needed to confirm these relationships. PMID:27564679

  12. Activity Patterns of St. Louis Encephalitis and West Nile Viruses in Free Ranging Birds during a Human Encephalitis Outbreak in Argentina

    PubMed Central

    Quaglia, Agustín Ignacio; Konigheim, Brenda Salomé; Boris, Analia Silvana; Aguilar, Juan Javier; Komar, Nicholas; Contigiani, Marta Silvia

    2016-01-01

    St. Louis encephalitis virus (SLEV) (Flavivirus) is a reemerging arbovirus in the southern cone of South America. In 2005, an outbreak of SLEV in central Argentina resulted in 47 human cases with 9 deaths. In Argentina, the ecology of SLEV is poorly understood. Because certain birds are the primary amplifiers in North America, we hypothesized that birds amplify SLEV in Argentina as well. We compared avian SLEV seroprevalence in a variety of ecosystems in and around Córdoba city from 2004 (before the epidemic) and 2005 (during the epidemic). We also explored spatial patterns to better understand the local ecology of SLEV transmission. Because West Nile virus (WNV) was also detected in Argentina in 2005, all analyses were also conducted for WNV. A total of 980 birds were sampled for detection of SLEV and WNV neutralizing antibodies. SLEV seroprevalence in birds increased 11-fold from 2004 to 2005. Our study demonstrated that a high proportion (99.3%) of local birds were susceptible to SLEV infection immediately prior to the 2005 outbreak, indicating that the vertebrate host population was primed to amplify SLEV. SLEV was found distributed in a variety of environments throughout the city of Córdoba. However, the force of viral transmission varied among sites. Fine scale differences in populations of vectors and vertebrate hosts would explain this variation. In summary, we showed that in 2005, both SLEV and to a lesser extent WNV circulated in the avian population. Eared Dove, Picui Ground-Dove and Great Kiskadee are strong candidates to amplify SLEV because of their exposure to the pathogen at the population level, and their widespread abundance. For the same reasons, Rufous Hornero may be an important maintenance host for WNV in central Argentina. Competence studies and vector feeding studies are needed to confirm these relationships. PMID:27564679

  13. Defensive Perimeter in the Central Nervous System: Predominance of Astrocytes and Astrogliosis during Recovery from Varicella-Zoster Virus Encephalitis

    PubMed Central

    Carpenter, John E.; Clayton, Amy C.; Halling, Kevin C.; Bonthius, Daniel J.; Buckingham, Erin M.; Jackson, Wallen; Dotzler, Steven M.; Card, J. Patrick; Enquist, Lynn W.

    2015-01-01

    ABSTRACT Varicella-zoster virus (VZV) is a highly neurotropic virus that can cause infections in both the peripheral nervous system and the central nervous system. Several studies of VZV reactivation in the peripheral nervous system (herpes zoster) have been published, while exceedingly few investigations have been carried out in a human brain. Notably, there is no animal model for VZV infection of the central nervous system. In this report, we characterized the cellular environment in the temporal lobe of a human subject who recovered from focal VZV encephalitis. The approach included not only VZV DNA/RNA analyses but also a delineation of infected cell types (neurons, microglia, oligodendrocytes, and astrocytes). The average VZV genome copy number per cell was 5. Several VZV regulatory and structural gene transcripts and products were detected. When colocalization studies were performed to determine which cell types harbored the viral proteins, the majority of infected cells were astrocytes, including aggregates of astrocytes. Evidence of syncytium formation within the aggregates included the continuity of cytoplasm positive for the VZV glycoprotein H (gH) fusion-complex protein within a cellular profile with as many as 80 distinct nuclei. As with other causes of brain injury, these results suggested that astrocytes likely formed a defensive perimeter around foci of VZV infection (astrogliosis). Because of the rarity of brain samples from living humans with VZV encephalitis, we compared our VZV results with those found in a rat encephalitis model following infection with the closely related pseudorabies virus and observed similar perimeters of gliosis. IMPORTANCE Investigations of VZV-infected human brain from living immunocompetent human subjects are exceedingly rare. Therefore, much of our knowledge of VZV neuropathogenesis is gained from studies of VZV-infected brains obtained at autopsy from immunocompromised patients. These are not optimal samples with which

  14. Complete Genome Sequences of Two Japanese Eel Endothelial Cell-Infecting Virus Strains Isolated in Japan.

    PubMed

    Naoi, Yuki; Okazaki, Sachiko; Katayama, Yukie; Omatsu, Tsutomu; Ono, Shin-Ichi; Mizutani, Tetsuya

    2015-01-01

    Japanese eel endothelial cell-infecting virus (JEECV) causes viral endothelial cell necrosis of eel (VECNE), resulting in severe economic losses in eel aquaculture in Japan. Here, we report the complete genome sequences of two new JEECV strains isolated from farmed Japanese eels. PMID:26564031

  15. Nucleic acid sequence-based amplification assays for rapid detection of West Nile and St. Louis encephalitis viruses.

    PubMed

    Lanciotti, R S; Kerst, A J

    2001-12-01

    The development and application of nucleic acid sequence-based amplification (NASBA) assays for the detection of West Nile (WN) and St. Louis encephalitis (SLE) viruses are reported. Two unique detection formats were developed for the NASBA assays: a postamplification detection step with a virus-specific internal capture probe and electrochemiluminescence (NASBA-ECL assay) and a real-time assay with 6-carboxyfluorescein-labeled virus-specific molecular beacon probes (NASBA-beacon assay). The sensitivities and specificities of these NASBA assays were compared to those of a newly described standard reverse transcription (RT)-PCR and TaqMan assays for SLE virus and to a previously published TaqMan assay for WN virus. The NASBA assays demonstrated exceptional sensitivities and specificities compared to those of virus isolation, the TaqMan assays, and standard RT-PCR, with the NASBA-beacon assay yielding results in less than 1 h. These assays should be of utility in the diagnostic laboratory to complement existing diagnostic testing methodologies and as a tool in conducting flavivirus surveillance in the United States. PMID:11724870

  16. [Detection of the Siberian Tick-borne Encephalitis Virus in the Xinjiang Uygur Autonomous Region, northwestern China].

    PubMed

    Liu, Ran; Zhang, Guilin; Liu, Xiaoming; Li, Yuchang; Zheng, Zhong; Sun, Xiang; Yang, Yinhui

    2016-01-01

    Until the recent emergence/re-emergence of human-pathogenic viruses in ticks, tick-borne viruses have been neglected as causative agents of human disease (particularly in China). To gain insight into the diversity of tick-borne viruses in Xinjiang Uygur Autonomous Region (northwestern China), we conducted illumina deep sequencing-based screening for virus-derived small RNAs in field-collected Ixodes persulcatus ticks. We found 32, 631 unique virus-matched reads. In particular, 77 reads mapped to the tick-borne group within the genus of Flavivirus, and covered 3.8%-2.4% viral genomes. In addition, 32 unique reads were specific to the Siberian subtype of tick-borne encephalitis viruses (TBEV-Sib) which have never been reported in Chinese TBE loci. We confirmed the potential existence of TBEV-Sib by amplification (using reverse transcription-polymerase chain reaction) of genomic fragments from the envelope gene or 3' genomic terminus from the pools of examined ticks. Both sequences demonstrated high homology to TBEV-Sib strains attached geographically to southern Siberia with nucleotide identity of 97.2%-95.5% and aminoacid identity of 99.4%-98.3%, respectively. In conclusion, we report, for the first time, detection of TBEV-Sib in the natural TBE loci of China. These novel data may provide genetic information for further isolation and epidemiologic investigation of TBEV-Sib. PMID:27295880

  17. [Involvement of the common shrew, Sorex araneus (Insectivora, Soricidae), in circulation of the tick-borne encephalitis virus in south-western Siberia].

    PubMed

    Bakhvalova, V N; Morozova, O V; Dobrotvorskiĭ, A K; Panov, V V; Matveeva, V A; Popova, R V; Korobova, S A

    2001-01-01

    We presented the data on the abundance of immature instars of the taiga tick Ixodes persulcatus Schuize on the common shrews Sorex araneus L. in natural foci of tick-borne encephalitis in the south of Western Siberia. Basing on the results of virological and serological studies we demonstrated a low effectiveness of this host species as a donor of disease agent strains, which are predominant in the territory under study, for ticks feeding on shrews. The analysis of samples taken from the young shrews in winter and spring using reverse RNA transcription with polymerase chain reaction and ELISA revealed occurRence of subvirion components of the tick-borne encephalitis (RNA and capsid protein E) ether in brain, liver or spleen in 90 percent of shrews (n = 42). Neither hemagglutination antigen nor infectious virus have been detected. We discussed a possible epizootic role of the maintenance of non-infectious tick-borne encephalitis virus in overwintering animals. PMID:11871252

  18. A humanised murine monoclonal antibody protects mice from Venezuelan equine encephalitis virus, Everglades virus and Mucambo virus when administered up to 48 h after airborne challenge

    SciTech Connect

    O'Brien, Lyn M. Goodchild, Sarah A.; Phillpotts, Robert J.; Perkins, Stuart D.

    2012-05-10

    Currently there are no licensed antiviral treatments for the Alphaviruses Venezuelan equine encephalitis virus (VEEV), Everglades virus and Mucambo virus. We previously developed a humanised version of the mouse monoclonal antibody 1A3B-7 (Hu1A3B-7) which exhibited a wide range of reactivity in vitro and was able to protect mice from infection with VEEV. Continued work with the humanised antibody has now demonstrated that it has the potential to be a new human therapeutic. Hu1A3B-7 successfully protected mice from infection with multiple Alphaviruses. The effectiveness of the humanisation process was determined by assessing proliferation responses in human T-cells to peptides derived from the murine and humanised versions of the V{sub H} and V{sub L} domains. This analysis showed that the number of human T-cell epitopes within the humanised antibody had been substantially reduced, indicating that Hu1A3B-7 may have reduced immunogenicity in vivo.

  19. Influence of the CCR-5/MIP-1 α Axis in the Pathogenesis of Rocio Virus Encephalitis in a Mouse Model

    PubMed Central

    Chávez, Juliana H.; França, Rafael F. O.; Oliveira, Carlo J. F.; de Aquino, Maria T. P.; Farias, Kleber J. S.; Machado, Paula R. L.; de Oliveira, Thelma F. M.; Yokosawa, Jonny; Soares, Edson G.; da Silva, João S.; da Fonseca, Benedito A. L.; Figueiredo, Luiz T. M.

    2013-01-01

    Rocio virus (ROCV) caused an outbreak of human encephalitis during the 1970s in Brazil and its immunopathogenesis remains poorly understood. CC-chemokine receptor 5 (CCR5) is a chemokine receptor that binds to macrophage inflammatory protein (MIP-1 α). Both molecules are associated with inflammatory cells migration during infections. In this study, we demonstrated the importance of the CCR5 and MIP-1 α, in the outcome of viral encephalitis of ROCV-infected mice. CCR5 and MIP-1 α knockout mice survived longer than wild-type (WT) ROCV-infected animals. In addition, knockout mice had reduced inflammation in the brain. Assessment of brain viral load showed mice virus detection five days post-infection in wild-type and CCR5−/− mice, while MIP-1 α−/− mice had lower viral loads seven days post-infection. Knockout mice required a higher lethal dose than wild-type mice as well. The CCR5/MIP-1 α axis may contribute to migration of infected cells to the brain and consequently affect the pathogenesis during ROCV infection. PMID:24080631

  20. Alcohol Abuse Enhances Neuroinflammation and Impairs Immune Responses in an Animal Model of Human Immunodeficiency Virus-1 Encephalitis

    PubMed Central

    Potula, Raghava; Haorah, James; Knipe, Bryan; Leibhart, Jessica; Chrastil, Jesse; Heilman, David; Dou, Huanyu; Reddy, Rindha; Ghorpade, Anuja; Persidsky, Yuri

    2006-01-01

    Neuroinflammatory disorders (including human immunodeficiency virus-1 encephalitis, HIVE) are associated with oxidative stress and inflammatory brain injury, and excessive alcohol use can exacerbate tissue damage. Using a murine model of HIVE, we investigated the effects of alcohol abuse on the clearance of virus-infected macrophages and neuroinflammation. Severe combined immunodeficient mice were reconstituted with human lymphocytes, and encephalitis was induced by intracranial injection of HIV-1-infected monocyte-derived macrophages (HIV-1+ MDM). Animals were fed an ethanol-containing diet beginning 2 weeks before lymphocyte engraftment and for the entire duration of the experiment. Lymphocyte engraftment was not altered by ethanol exposure. Alcohol-mediated immunosuppression in ethanol-fed mice was manifested by a significant decrease in CD8+/interferon-γ+ T lymphocytes, a fivefold increase in viremia, and diminished expression of immunoproteasomes in the spleen. Although both groups showed similar amounts of CD8+ T-lymphocyte infiltration in brain areas containing HIV-1+ MDMs, ethanol-fed mice featured double the amounts of HIV-1+ MDMs in the brain compared to controls. Ethanol-exposed mice demonstrated higher microglial reaction and enhanced oxidative stress. Alcohol exposure impaired immune responses (increased viremia, decreased immunoproteasome levels, and prevented efficient elimination of HIV-1+ MDMs) and enhanced neuroinflammation in HIVE mice. Thus, alcohol abuse could be a co-factor in progression of HIV-1 infection of the brain. PMID:16565506

  1. Development of a multi-target TaqMan assay to detect eastern equine encephalitis virus variants in mosquitoes.

    PubMed

    Armstrong, Philip M; Prince, Nicholanna; Andreadis, Theodore G

    2012-10-01

    Disease outbreaks caused by eastern equine encephalitis virus (EEEV; Togaviridae, Alphavirus) may be prevented by implementing effective surveillance and intervention strategies directed against the mosquito vector. Methods for EEEV detection in mosquitoes include a real-time reverse transcriptase PCR technique (TaqMan assay), but we report its failure to detect variants isolated in Connecticut in 2011, due to a single base-pair mismatch in the probe-binding site. To improve the molecular detection of EEEV, we developed a multi-target TaqMan assay by adding a second primer/probe set to provide redundant targets for EEEV detection. The multi-target TaqMan assay had similar performance characteristics to the conventional assay, but also detected newly-evolving strains of EEEV. The approach described here increases the reliability of the TaqMan assay by creating back-up targets for virus detection without sacrificing sensitivity or specificity. PMID:22835151

  2. Comprehensive Mapping of Common Immunodominant Epitopes in the Eastern Equine Encephalitis Virus E2 Protein Recognized by Avian Antibody Responses

    PubMed Central

    Sun, EnCheng; Zhao, Jing; Sun, Liang; Xu, QingYuan; Yang, Tao; Qin, YongLi; Wang, WenShi; Wei, Peng; Sun, Jing; Wu, DongLai

    2013-01-01

    Eastern equine encephalitis virus (EEEV) is a mosquito-borne virus that can cause both human and equine encephalitis with high case fatality rates. EEEV can also be widespread among birds, including pheasants, ostriches, emu, turkeys, whooping cranes and chickens. The E2 protein of EEEV and other Alphaviruses is an important immunogenic protein that elicits antibodies of diagnostic value. While many therapeutic and diagnostic applications of E2 protein-specific antibodies have been reported, the specific epitopes on E2 protein recognized by the antibody responses of different susceptible hosts, including avian species, remain poorly defined. In the present study, the avian E2-reactive polyclonal antibody (PAb) response was mapped to linear peptide epitopes using PAbs elicited in chickens and ducks following immunization with recombinant EEEV E2 protein and a series of 42 partially overlapping peptides covering the entire EEEV E2 protein. We identified 12 and 13 peptides recognized by the chicken and duck PAb response, respectively. Six of these linear peptides were commonly recognized by PAbs elicited in both avian species. Among them five epitopes recognized by both avian, the epitopes located at amino acids 211–226 and 331–352 were conserved among the EEEV antigenic complex, but not other associated alphaviruses, whereas the epitopes at amino acids 11–26, 30–45 and 151–166 were specific to EEEV subtype I. The five common peptide epitopes were not recognized by avian PAbs against Avian Influenza Virus (AIV) and Duck Plague Virus (DPV). The identification and characterization of EEEV E2 antibody epitopes may be aid the development of diagnostic tools and facilitate the design of epitope-based vaccines for EEEV. These results also offer information with which to study the structure of EEEV E2 protein. PMID:23922704

  3. Comprehensive mapping of common immunodominant epitopes in the eastern equine encephalitis virus E2 protein recognized by avian antibody responses.

    PubMed

    Sun, Encheng; Zhao, Jing; Sun, Liang; Xu, Qingyuan; Yang, Tao; Qin, Yongli; Wang, Wenshi; Wei, Peng; Sun, Jing; Wu, Donglai

    2013-01-01

    Eastern equine encephalitis virus (EEEV) is a mosquito-borne virus that can cause both human and equine encephalitis with high case fatality rates. EEEV can also be widespread among birds, including pheasants, ostriches, emu, turkeys, whooping cranes and chickens. The E2 protein of EEEV and other Alphaviruses is an important immunogenic protein that elicits antibodies of diagnostic value. While many therapeutic and diagnostic applications of E2 protein-specific antibodies have been reported, the specific epitopes on E2 protein recognized by the antibody responses of different susceptible hosts, including avian species, remain poorly defined. In the present study, the avian E2-reactive polyclonal antibody (PAb) response was mapped to linear peptide epitopes using PAbs elicited in chickens and ducks following immunization with recombinant EEEV E2 protein and a series of 42 partially overlapping peptides covering the entire EEEV E2 protein. We identified 12 and 13 peptides recognized by the chicken and duck PAb response, respectively. Six of these linear peptides were commonly recognized by PAbs elicited in both avian species. Among them five epitopes recognized by both avian, the epitopes located at amino acids 211-226 and 331-352 were conserved among the EEEV antigenic complex, but not other associated alphaviruses, whereas the epitopes at amino acids 11-26, 30-45 and 151-166 were specific to EEEV subtype I. The five common peptide epitopes were not recognized by avian PAbs against Avian Influenza Virus (AIV) and Duck Plague Virus (DPV). The identification and characterization of EEEV E2 antibody epitopes may be aid the development of diagnostic tools and facilitate the design of epitope-based vaccines for EEEV. These results also offer information with which to study the structure of EEEV E2 protein. PMID:23922704

  4. Infiltration Pattern of Blood Monocytes into the Central Nervous System during Experimental Herpes Simplex Virus Encephalitis

    PubMed Central

    Menasria, Rafik; Canivet, Coraline; Piret, Jocelyne; Boivin, Guy

    2015-01-01

    The kinetics and distribution of infiltrating blood monocytes into the central nervous system and their involvement in the cerebral immune response together with resident macrophages, namely microglia, were evaluated in experimental herpes simplex virus 1 (HSV-1) encephalitis (HSE). To distinguish microglia from blood monocyte-derived macrophages, chimeras were generated by conditioning C57BL/6 recipient mice with chemotherapy regimen followed by transplantation of bone morrow-derived cells that expressed the green fluorescent protein. Mice were infected intranasally with a sub-lethal dose of HSV-1 (1.2x106 plaque forming units). Brains were harvested prior to and on days 4, 6, 8 and 10 post-infection for flow cytometry and immunohistochemistry analysis. The amounts of neutrophils (P<0.05) and «Ly6Chi» inflammatory monocytes (P<0.001) significantly increased in the CNS compared to non-infected controls on day 6 post-infection, which corresponded to more severe clinical signs of HSE. Levels decreased on day 8 for both leukocytes subpopulations (P<0.05 for inflammatory monocytes compared to non-infected controls) to reach baseline levels on day 10 following infection. The percentage of «Ly6Clow» patrolling monocytes significantly increased (P<0.01) at a later time point (day 8), which correlated with the resolution phase of HSE. Histological analysis demonstrated that blood leukocytes colonized mostly the olfactory bulb and the brainstem, which corresponded to regions where HSV-1 particles were detected. Furthermore, infiltrating cells from the monocytic lineage could differentiate into activated local tissue macrophages that express the microglia marker, ionized calcium-binding adaptor molecule 1. The lack of albumin detection in the brain parenchyma of infected mice showed that the infiltration of blood leukocytes was not necessarily related to a breakdown of the blood-brain barrier but could be the result of a functional recruitment. Thus, our findings suggest

  5. Infiltration Pattern of Blood Monocytes into the Central Nervous System during Experimental Herpes Simplex Virus Encephalitis.

    PubMed

    Menasria, Rafik; Canivet, Coraline; Piret, Jocelyne; Boivin, Guy

    2015-01-01

    The kinetics and distribution of infiltrating blood monocytes into the central nervous system and their involvement in the cerebral immune response together with resident macrophages, namely microglia, were evaluated in experimental herpes simplex virus 1 (HSV-1) encephalitis (HSE). To distinguish microglia from blood monocyte-derived macrophages, chimeras were generated by conditioning C57BL/6 recipient mice with chemotherapy regimen followed by transplantation of bone morrow-derived cells that expressed the green fluorescent protein. Mice were infected intranasally with a sub-lethal dose of HSV-1 (1.2 x 10(6) plaque forming units). Brains were harvested prior to and on days 4, 6, 8 and 10 post-infection for flow cytometry and immunohistochemistry analysis. The amounts of neutrophils (P < 0.05) and "Ly6C hi" inflammatory monocytes (P < 0.001) significantly increased in the CNS compared to non-infected controls on day 6 post-infection, which corresponded to more severe clinical signs of HSE. Levels decreased on day 8 for both leukocytes subpopulations (P < 0.05 for inflammatory monocytes compared to non-infected controls) to reach baseline levels on day 10 following infection. The percentage of "Ly6C low" patrolling monocytes significantly increased (P < 0.01) at a later time point (day 8), which correlated with the resolution phase of HSE. Histological analysis demonstrated that blood leukocytes colonized mostly the olfactory bulb and the brainstem, which corresponded to regions where HSV-1 particles were detected. Furthermore, infiltrating cells from the monocytic lineage could differentiate into activated local tissue macrophages that express the microglia marker, ionized calcium-binding adaptor molecule 1. The lack of albumin detection in the brain parenchyma of infected mice showed that the infiltration of blood leukocytes was not necessarily related to a breakdown of the blood-brain barrier but could be the result of a functional recruitment. Thus, our

  6. Immunoblot Profile as Predictor of Toxoplasmic Encephalitis in Patients Infected with Human Immunodeficiency Virus

    PubMed Central

    Leport, Catherine; Franck, Jacqueline; Chene, Genevieve; Derouin, Francis; Ecobichon, Jean-Luc; Pueyo, Sophie; Miro, Jose M.; Luft, Benjamin J.; Morlat, Philippe; Dumon, Henri

    2001-01-01

    In order to define more accurately human immunodeficiency virus-infected patients at risk of developing toxoplasmic encephalitis (TE), we assessed the prognostic significance of the anti-Toxoplasma gondii immunoglobulin G (IgG) immunoblot profile, in addition to AIDS stage, a CD4+ cell count <50/mm3, and an antibody titer ≥150 IU/ml, in patients with CD4 cell counts <200/mm3 and seropositive for T. gondii. Baseline serum samples from 152 patients included in the placebo arm of the ANRS 005-ACTG 154 trial (pyrimethamine versus placebo) were used. The IgG immunoblot profile was determined using a Toxoplasma lysate and read using the Kodak Digital Science 1D image analysis software. Mean follow-up was 15.1 months, and the 1-year incidence of TE was 15.9%. The cumulative probability of TE varied according to the type and number of anti-T. gondii IgG bands and reached 65% at 12 months for patients with IgG bands of 25 and 22 kDa. In a Cox model adjusted for age, gender, Centers for Disease Control and Prevention (CDC) clinical stage, and CD4 and CD8 cell counts, the incidence of TE was higher when the IgG 22-kDa band (hazard ratio [HR] = 5.4; P < 0.001), the IgG 25-kDa band (HR = 4.7; P < 0.001), or the IgG 69-kDa band (HR = 3.4; P < 0.001) was present and was higher for patients at CDC stage C (HR = 4.9; P < 0.001). T. gondii antibody titer and CD4 cell count were not predictive of TE. Thus, detection of IgG bands of 25, 22, and/or 69 kDa may be helpful for deciding when primary prophylaxis for TE should be started or discontinued, especially in the era of highly active antiretroviral therapy. PMID:11329461

  7. Cognitive and Learning Strategies for Longstanding Temporal Lobe Lesions in a Child Who Suffered from "Herpes Simplex" Virus Encephalitis: A Case Study over 10 Years

    ERIC Educational Resources Information Center

    van Schoor, A. N.; Naude, H.; van Rensburg, M.; Pretorius, E.; Boon, J. M.

    2005-01-01

    This article presents a case study indicating that "Herpes simplex" virus (HSV) encephalitis may cause permanent learning disabilities due to damage to the temporal lobes as it discusses the results of a case study extending over 10 years to determine the long-term effects on both the anatomy of the brain and the intellectual functioning of the…

  8. Cognitive and Learning Strategies for Longstanding Temporal Lobe Lesions in a Child Who Suffered from "Herpes Simplex" Virus Encephalitis: A Case Study over 10 Years

    ERIC Educational Resources Information Center

    van Schoor, A. N.; Naude, H.; van Rensburg, M.; Pretorius, E.; Boon, J. M.

    2004-01-01

    This article presents a case study indicating that "Herpes simplex" virus (HSV) encephalitis may cause permanent learning disabilities due to damage to the temporal lobes, as it discusses the results of a case study extending over 10 years to determine the long-term effects on both the anatomy of the brain and the intellectual functioning of the…

  9. La Crosse Encephalitis Virus Infection in Field-Collected Aedes albopictus, Aedes japonicus, and Aedes triseriatus in Tennessee.

    PubMed

    Westby, Katie M; Fritzen, Charissa; Paulsen, Dave; Poindexter, Stephanie; Moncayo, Abelardo C

    2015-09-01

    La Crosse virus (LACV) is a mosquito-borne virus and a major cause of pediatric encephalitis in the USA. La Crosse virus emerged in Tennessee and other states in the Appalachian region in 1997. We investigated LACV infection rates and seasonal abundances of the native mosquito vector, Aedes triseriatus, and 2 recently introduced mosquito species, Ae. albopictus and Ae. japonicus, in an emerging disease focus in Tennessee. Mosquitoes were collected using multiple trapping methods specific for Aedes mosquitoes at recent human case sites. Mosquito pools were tested via reverse transcriptase-polymerase chain reaction (RT-PCR) of the S segment to detect multiple Bunyamwera and California serogroup viruses, including LACV, as well as real-time RT-PCR of the M segment. A total of 54 mosquito pools were positive, including wild-caught adult females and laboratory-reared adults, demonstrating transovarial transmission in all 3 species. Maximum likelihood estimates (per 1,000 mosquitoes) were 2.72 for Ae. triseriatus, 3.01 for Ae. albopictus, and 0.63 for Ae. japonicus. We conclude that Ae. triseriatus and Ae. albopictus are important LACV vectors and that Ae. japonicus also may be involved in virus maintenance and transmission. PMID:26375904

  10. Recent progress in West Nile virus diagnosis and vaccination

    PubMed Central

    2012-01-01

    West Nile virus (WNV) is a positive-stranded RNA virus belonging to the Flaviviridae family, a large family with 3 main genera (flavivirus, hepacivirus and pestivirus). Among these viruses, there are several globally relevant human pathogens including the mosquito-borne dengue virus (DENV), yellow fever virus (YFV), Japanese encephalitis virus (JEV) and West Nile virus (WNV), as well as tick-borne viruses such as tick-borne encephalitis virus (TBEV). Since the mid-1990s, outbreaks of WN fever and encephalitis have occurred throughout the world and WNV is now endemic in Africa, Asia, Australia, the Middle East, Europe and the Unites States. This review describes the molecular virology, epidemiology, pathogenesis, and highlights recent progress regarding diagnosis and vaccination against WNV infections. PMID:22380523

  11. Encephalitis Caused by Chikungunya Virus in a Traveler from the Kingdom of Tonga

    PubMed Central

    Nelson, Joanna; Waggoner, Jesse J.; Sahoo, Malaya K.; Grant, Philip M.

    2014-01-01

    Febrile travelers from countries with unique endemic pathogens pose a significant diagnostic challenge. In this report, we describe the case of a Tongan man presenting with fever, rash, and altered mental status. The diagnosis of Chikungunya encephalitis was made using a laboratory-developed real-time RT-PCR and serologic testing. PMID:24958800

  12. Nuclear receptor REV-ERBα mediates circadian sensitivity to mortality in murine vesicular stomatitis virus-induced encephalitis.

    PubMed

    Gagnidze, Khatuna; Hajdarovic, Kaitlyn H; Moskalenko, Marina; Karatsoreos, Ilia N; McEwen, Bruce S; Bulloch, Karen

    2016-05-17

    Certain components and functions of the immune system, most notably cytokine production and immune cell migration, are under circadian regulation. Such regulation suggests that circadian rhythms may have an effect on disease onset, progression, and resolution. In the vesicular stomatitis virus (VSV)-induced encephalitis model, the replication, caudal penetration, and survivability of intranasally applied VSV depends on both innate and adaptive immune mechanisms. In the current study, we investigated the effect of circadian time of infection on the progression and outcome of VSV-induced encephalitis and demonstrated a significant decrease in the survival rate in mice infected at the start of the rest cycle, zeitgeber time 0 (ZT0). The lower survival rate in these mice was associated with higher levels of circulating chemokine (C-C motif) ligand 2 (CCL2), a greater number of peripherally derived immune cells accumulating in the olfactory bulb (OB), and increased production of proinflammatory cytokines, indicating an immune-mediated pathology. We also found that the acrophase of molecular circadian clock component REV-ERBα mRNA expression in the OB coincides with the start of the active cycle, ZT12, when VSV infection results in a more favorable outcome. This result led us to hypothesize that REV-ERBα may mediate the circadian effect on survival following VSV infection. Blocking REV-ERBα activity before VSV administration resulted in a significant increase in the expression of CCL2 and decreased survival in mice infected at the start of the active cycle. These data demonstrate that REV-ERBα-mediated inhibition of CCL2 expression during viral-induced encephalitis may have a protective effect. PMID:27143721

  13. Exploring Genomic, Geographic and Virulence Interactions among Epidemic and Non-Epidemic St. Louis Encephalitis Virus (Flavivirus) Strains

    PubMed Central

    Iserte, Javier A.; Quaglia, Agustín I.; Singh, Amber; Logue, Christopher H.; Powers, Ann M.; Contigiani, Marta S.

    2015-01-01

    St. Louis encephalitis virus (SLEV) is a re-emerging arbovirus in South America. In 2005, an encephalitis outbreak caused by SLEV was reported in Argentina. The reason for the outbreak remains unknown, but may have been related to virological factors, changes in vectors populations, avian amplifying hosts, and/or environmental conditions. The main goal of this study was to characterize the complete genome of epidemic and non-epidemic SLEV strains from Argentina. Seventeen amino acid changes were detected; ten were non-conservative and located in proteins E, NS1, NS3 and NS5. Phylogenetic analysis showed two major clades based on geography: the North America and northern Central America (NAnCA) clade and the South America and southern Central America (SAsCA) clade. Interestingly, the presence of SAsCA genotype V SLEV strains in the NAnCA clade was reported in California, Florida and Texas, overlapping with known bird migration flyways. This work represents the first step in understanding the molecular mechanisms underlying virulence and biological variation among SLEV strains. PMID:26312485

  14. Early detection of tick-borne encephalitis virus spatial distribution and activity in the province of Trento, northern Italy.

    PubMed

    Rizzoli, Annapaola; Neteler, Markus; Rosà, Roberto; Versini, Walter; Cristofolini, Antonio; Bregoli, Marco; Buckley, Alan; Gould, Ernest A

    2007-05-01

    New human cases of tick-borne encephalitis (TBE) have recently been recorded outside the recognised foci of this disease, i.e. in the province of Trento in northern Italy. In order to predict the highest risk areas for increased TBE virus activity, we have combined cross-sectional serological data, obtained from 459 domestic goats, with analysis of the autumnal cooling rate based on Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) data. A significant relationship between finding antibodies against the virus in serum (seroprevalence) in goats and the autumnal cooling rate was detected, indicating that the transmission intensity of the virus does not only vary spatially, but also in relation to climatic factors. Virus seroprevalence in goats was correlated with the occurrence of TBE in humans and also with the average number of forestry workers' tick bites, demonstrating that serological screening of domestic animals, combined with an analysis of the autumnal cooling rate, can be used as early-warning predictors of TBE risk in humans. PMID:18686242

  15. Venezuelan Equine Encephalitis Virus Replicon Particle Vaccine Protects Nonhuman Primates from Intramuscular and Aerosol Challenge with Ebolavirus

    PubMed Central

    Herbert, Andrew S.; Kuehne, Ana I.; Barth, James F.; Ortiz, Ramon A.; Nichols, Donald K.; Zak, Samantha E.; Stonier, Spencer W.; Muhammad, Majidat A.; Bakken, Russell R.; Prugar, Laura I.; Olinger, Gene G.; Groebner, Jennifer L.; Lee, John S.; Pratt, William D.; Custer, Max; Kamrud, Kurt I.; Smith, Jonathan F.; Hart, Mary Kate

    2013-01-01

    There are no vaccines or therapeutics currently approved for the prevention or treatment of ebolavirus infection. Previously, a replicon vaccine based on Venezuelan equine encephalitis virus (VEEV) demonstrated protective efficacy against Marburg virus in nonhuman primates. Here, we report the protective efficacy of Sudan virus (SUDV)- and Ebola virus (EBOV)-specific VEEV replicon particle (VRP) vaccines in nonhuman primates. VRP vaccines were developed to express the glycoprotein (GP) of either SUDV or EBOV. A single intramuscular vaccination of cynomolgus macaques with VRP expressing SUDV GP provided complete protection against intramuscular challenge with SUDV. Vaccination against SUDV and subsequent survival of SUDV challenge did not fully protect cynomolgus macaques against intramuscular EBOV back-challenge. However, a single simultaneous intramuscular vaccination with VRP expressing SUDV GP combined with VRP expressing EBOV GP did provide complete protection against intramuscular challenge with either SUDV or EBOV in cynomolgus macaques. Finally, intramuscular vaccination with VRP expressing SUDV GP completely protected cynomolgus macaques when challenged with aerosolized SUDV, although complete protection against aerosol challenge required two vaccinations with this vaccine. PMID:23408633

  16. Infectious Causes of Encephalitis and Meningoencephalitis in Thailand, 2003–2005

    PubMed Central

    Campbell, Angela P.; Supawat, Krongkaew; Liamsuwan, Sahas; Chotpitayasunondh, Tawee; Laptikulthum, Somsak; Viriyavejakul, Akravudh; Tantirittisak, Tasanee; Tunlayadechanont, Supoch; Visudtibhan, Anannit; Vasiknanonte, Punnee; Janjindamai, Supachai; Boonluksiri, Pairoj; Rajborirug, Kiatsak; Watanaveeradej, Veerachai; Khetsuriani, Nino; Dowell, Scott F.

    2015-01-01

    Acute encephalitis is a severe neurologic syndrome. Determining etiology from among ≈100 possible agents is difficult. To identify infectious etiologies of encephalitis in Thailand, we conducted surveillance in 7 hospitals during July 2003–August 2005 and selected patients with acute onset of brain dysfunction with fever or hypothermia and with abnormalities seen on neuroimages or electroencephalograms or with cerebrospinal fluid pleocytosis. Blood and cerebrospinal fluid were tested for >30 pathogens. Among 149 case-patients, median age was 12 (range 0–83) years, 84 (56%) were male, and 15 (10%) died. Etiology was confirmed or probable for 54 (36%) and possible or unknown for 95 (64%). Among confirmed or probable etiologies, the leading pathogens were Japanese encephalitis virus, enteroviruses, and Orientia tsutsugamushi. No samples were positive for chikungunya, Nipah, or West Nile viruses; Bartonella henselae; or malaria parasites. Although a broad range of infectious agents was identified, the etiology of most cases remains unknown. PMID:25627940

  17. Vector Competence of Culex (Melanoconion) taeniopus for Equine-Virulent Subtype IE Strains of Venezuelan Equine Encephalitis Virus

    PubMed Central

    Deardorff, Eleanor R.; Weaver, Scott C.

    2010-01-01

    The mosquito Culex (Melanoconion) taeniopus is a proven vector of enzootic Venezuelan equine encephalitis virus (VEEV) subtype IE in Central America. It has been shown to be highly susceptible to infection by this subtype, and conversely to be highly refractory to infection by other VEEV subtypes. During the 1990s in southern coastal Mexico, two VEE epizootics in horses were attributed to subtype IE VEEV. These outbreaks were associated with VEEV strains with an altered infection phenotype for the epizootic mosquito vector, Aedes (Ochlerotatus) taeniorhynchus. To determine the infectivity for the enzootic vector, Culex taeniopus, mosquitoes from a recently established colony were orally exposed to VEEV strains from the outbreak. The equine-virulent strains exhibited high infectivity and transmission potential comparable to a traditional enzootic subtype IE VEEV strain. Thus, subtype IE VEEV strains in Chiapas are able to efficiently infect enzootic and epizootic vectors and cause morbidity and mortality in horses. PMID:20519599

  18. Isolation and characterization of a Far-Eastern strain of tick-borne encephalitis virus in China.

    PubMed

    Zhang, Xiaowei; Zheng, Zhenhua; Shu, Bo; Mao, Panyong; Bai, Bingke; Hu, Qinxue; Cui, Zongqiang; Wang, Hanzhong

    2016-02-01

    Tick-borne encephalitis virus (TBEV) is a leading cause of human neurological infection in many parts of Europe and Asia. Although several TBEV isolates have been reported, current understanding of the biological characteristics of a Chinese strain is limited. In this study, a Far-Eastern strain of TBEV designated WH2012 was isolated in northern China. Its genome has been sequenced and found to be closely related to other Chinese TBEV isolates. Human cell lines of neural origin exposed to WH2012 showed cytopathic effects and WH2012 replicated most efficiently in human neuroblastoma cells SK-N-SH. In addition, WH2012 possessed a pathogenic potential in the mouse model, characterized by inducing a complete paralysis in the hindlimbs with a fatal outcome. We herein describe the first data regarding biological properties of TBEV from China. This study may help future research on pathogenic mechanisms of the neurological disease induced by TBEV infection in China. PMID:26555163

  19. Diagnostic imaging of herpes simplex virus encephalitis using a radiolabeled antiviral drug: autoradiographic assessment in an animal model

    SciTech Connect

    Saito, Y.; Rubenstein, R.; Price, R.W.; Fox, J.J.; Watanabe, K.A.

    1984-06-01

    To develop a new approach to the diagnosis of herpes simplex encephalitis, we used a radiolabeled antiviral drug, 2'-fluoro-5-methyl-1-beta-D-arabinosyluracil labeled with carbon 14 ((14C)FMAU), as a probe for selectively imaging brain infection in a rat model by quantitative autoradiography. A high correlation was found between focal infection, as defined by immunoperoxidase viral antigen staining, and increased regional (14C)FMAU uptake in brain sections. Two potential sources of false-positive imaging were defined: high concentrations of drug in the choroid plexus because of its higher permeability compared with brain, and drug sequestration by proliferating uninfected cell populations. Our results support the soundness of the proposed strategy of using a labeled antiviral drug that is selectively phosphorylated by herpes simplex virus type 1 thymidine kinase in conjunction with scanning methods for human diagnosis, and also define some of the factors that must be taken into account when planning clinical application.

  20. 1,5-Iodonaphthyl azide-inactivated V3526 protects against aerosol challenge with virulent venezuelan equine encephalitis virus.

    PubMed

    Gupta, Paridhi; Sharma, Anuj; Spurgers, Kevin B; Bakken, Russell R; Eccleston, Lori T; Cohen, Jeffrey W; Honnold, Shelley P; Glass, Pamela J; Maheshwari, Radha K

    2016-05-27

    Venezuelan equine encephalitis virus (VEEV) is a New World alphavirus. VEEV is highly infectious in aerosolized form and has been identified as a bio-terrorism agent. There is no licensed vaccine for prophylaxis against VEEV. The current IND vaccine is poorly immunogenic and does not protect against an aerosol challenge with virulent VEEV. We have previously shown that VEEV inactivated by 1,5-iodonaphthyl azide (INA) protects against footpad challenge with virulent VEEV. In this study, we inactivated an attenuated strain of VEEV, V3526, with INA and evaluated its protective efficacy against aerosol challenge with wild type VEEV. We demonstrated that among three routes of immunization, intramuscular immunization with INA-inactivate V3526 (INA-iV3526) provided complete protection against aerosol challenge with virulent VEEV. Our data suggests that INA-iV3526 can be explored further for development as an effective vaccine candidate against aerosol challenge of virulent VEEV. PMID:27129427

  1. Outcome after childhood encephalitis.

    PubMed

    Rantala, H; Uhari, M; Uhari, M; Saukkonen, A; Sorri, M

    1991-10-01

    The prognosis for 73 children treated for encephalitis between 1973 and 1983 was evaluated. 70 children participated in a follow-up examination 2.4 to 12.9 years after the acute phase of the disease. The 61 school-aged children had lower performance and full-scale IQs than their randomly selected, age- and sex-matched controls. Visual acuity was more often reduced, and they more often had focal slowing on EEG and electronystagmogram abnormalities. Clinically, these differences were not significant. Encephalitis with a poor prognosis occurred seldom, the incidence being 3.5 cases per one million children at risk annually. These results show that the prognosis for childhood encephalitis is much better than anticipated on the basis of experience mainly with herpes simplex virus encephalitis. PMID:1743408

  2. Effect of Holding Conditions on the Detection of Chikungunya and Venezuelan Equine Encephalitis Viruses in Mosquito Pools.

    PubMed

    Andrews, Elizabeth S; Turell, Michael J

    2016-03-01

    Emerging and re-emerging arboviruses continue to be a threat to global public health, and viral surveillance of mosquito populations is critical for mosquito control operations. Due to the tropical climate of many of the affected areas, it may be difficult to maintain a cold chain as the samples travel from collection sites to laboratories for testing. We determined how suboptimal holding temperatures affected the ability to detect viruses in pools of mosquitoes. Adult female Aedes albopictus and Ae. taeniorhynchus individuals were inoculated with chikungunya virus or Venezuelan equine encephalitis virus suspensions, respectively, and placed at 26°C for 8 days. One infected mosquito was then added to a vial of 24 negative mosquitoes and held at -80°C, -20°C, 4°C, 22°C, or 35°C for up to 14 days. Mosquito pools were analyzed for both infectious virus by plaque assay and for viral ribonucleic acid (RNA) with reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR). At higher temperatures, the amount of infectious virus decreased rapidly, but viruses in samples held at 4°C or lower remained relatively stable. In contrast, viral RNA was detectable from pools held at all temperatures and holding times by RT-qPCR. Cycle threshold (Ct) values increased as temperatures and holding times increased. These findings suggest that if viral RNA detection is the goal of surveillance efforts, then mosquito pools do not require storage at ≤4°C. This enhances the feasibility of field-based arbovirus surveillance programs in which maintaining a cold chain may not be a possibility. PMID:27105216

  3. Repeated emergence of epidemic/epizootic Venezuelan equine encephalitis from a single genotype of enzootic subtype ID virus.

    PubMed Central

    Powers, A M; Oberste, M S; Brault, A C; Rico-Hesse, R; Schmura, S M; Smith, J F; Kang, W; Sweeney, W P; Weaver, S C

    1997-01-01

    Venezuelan equine encephalitis (VEE) epidemics and equine epizootics occurred periodically in the Americas from the 1920s until the early 1970s, when the causative viruses, subtypes IAB and IC, were postulated to have become extinct. Recent outbreaks in Columbia and Venezuela have renewed interest in the source of epidemic/epizootic viruses and their mechanism of interepizootic maintenance. We performed phylogenetic analyses of VEE virus isolates spanning the entire temporal and geographic range of strains available, using 857-nucleotide reverse transcription-PCR products including the E3 and E2 genes. Analyses indicated that epidemic/epizootic viruses are closely related to four distinct, enzootic subtype ID-like lineages. One of these lineages, which occurs in Columbia, Peru, and Venezuela, also included all of the epidemic/epizootic isolates; the remaining three ID-like lineages, which occur in Panama, Peru, Florida, coastal Ecuador, and southwestern Columbia, were apparently not associated with epizootic VEE emergence. Within the Columbia/Peru/Venezuela lineage, three distinct monophyletic groups of epidemic/epizootic viruses were delineated, indicating that VEE emergence has occurred independently at least three times (convergent evolution). Representative, complete E2 amino acid sequences were compared to identify potential determinants of equine virulence and epizootic emergence. Amino acids implicated previously in laboratory mouse attenuation generally did not vary among the natural isolates that we examined, indicating that they probably are not involved in equine virulence changes associated with VEE emergence. Most informative amino acids correlated with phylogenetic relationships rather than phenotypic characteristics, suggesting that VEE emergence has resulted from several distinct combinations of mutations that generate viruses with similar antigenic and equine virulence phenotypes. PMID:9261393

  4. Genetic characterization of Venezuelan equine encephalitis virus from Bolivia, Ecuador and Peru: identification of a new subtype ID lineage.

    PubMed

    Aguilar, Patricia V; Adams, A Paige; Suárez, Victor; Beingolea, Luis; Vargas, Jorge; Manock, Stephen; Freire, Juan; Espinoza, Willan R; Felices, Vidal; Diaz, Ana; Liang, Xiaodong; Roca, Yelin; Weaver, Scott C; Kochel, Tadeusz J

    2009-01-01

    Venezuelan equine encephalitis virus (VEEV) has been responsible for hundreds of thousands of human and equine cases of severe disease in the Americas. A passive surveillance study was conducted in Peru, Bolivia and Ecuador to determine the arboviral etiology of febrile illness. Patients with suspected viral-associated, acute, undifferentiated febrile illness of <7 days duration were enrolled in the study and blood samples were obtained from each patient and assayed by virus isolation. Demographic and clinical information from each patient was also obtained at the time of voluntary enrollment. In 2005-2007, cases of Venezuelan equine encephalitis (VEE) were diagnosed for the first time in residents of Bolivia; the patients did not report traveling, suggesting endemic circulation of VEEV in Bolivia. In 2001 and 2003, VEE cases were also identified in Ecuador. Since 1993, VEEV has been continuously isolated from patients in Loreto, Peru, and more recently (2005), in Madre de Dios, Peru. We performed phylogenetic analyses with VEEV from Bolivia, Ecuador and Peru and compared their relationships to strains from other parts of South America. We found that VEEV subtype ID Panama/Peru genotype is the predominant one circulating in Peru. We also demonstrated that VEEV subtype ID strains circulating in Ecuador belong to the Colombia/Venezuela genotype and VEEV from Madre de Dios, Peru and Cochabamba, Bolivia belong to a new ID genotype. In summary, we identified a new major lineage of enzootic VEEV subtype ID, information that could aid in the understanding of the emergence and evolution of VEEV in South America. PMID:19753102

  5. Specificity and Dynamics of Effector and Memory CD8 T Cell Responses in Human Tick-Borne Encephalitis Virus Infection

    PubMed Central

    Blom, Kim; Braun, Monika; Pakalniene, Jolita; Dailidyte, Laura; Béziat, Vivien; Lampen, Margit H.; Klingström, Jonas; Lagerqvist, Nina; Kjerstadius, Torbjörn; Michaëlsson, Jakob; Lindquist, Lars; Ljunggren, Hans-Gustaf; Sandberg, Johan K.; Mickiene, Aukse; Gredmark-Russ, Sara

    2015-01-01

    Tick-borne encephalitis virus (TBEV) is transferred to humans by ticks. The virus causes tick-borne encephalitis (TBE) with symptoms such as meningitis and meningoencephalitis. About one third of the patients suffer from long-lasting sequelae after clearance of the infection. Studies of the immune response during TBEV-infection are essential to the understanding of host responses to TBEV-infection and for the development of therapeutics. Here, we studied in detail the primary CD8 T cell response to TBEV in patients with acute TBE. Peripheral blood CD8 T cells mounted a considerable response to TBEV-infection as assessed by Ki67 and CD38 co-expression. These activated cells showed a CD45RA-CCR7-CD127- phenotype at day 7 after hospitalization, phenotypically defining them as effector cells. An immunodominant HLA-A2-restricted TBEV epitope was identified and utilized to study the characteristics and temporal dynamics of the antigen-specific response. The functional profile of TBEV-specific CD8 T cells was dominated by variants of mono-functional cells as the effector response matured. Antigen-specific CD8 T cells predominantly displayed a distinct Eomes+Ki67+T-bet+ effector phenotype at the peak of the response, which transitioned to an Eomes-Ki67-T-bet+ phenotype as the infection resolved and memory was established. These transcription factors thus characterize and discriminate stages of the antigen-specific T cell response during acute TBEV-infection. Altogether, CD8 T cells responded strongly to acute TBEV infection and passed through an effector phase, prior to gradual differentiation into memory cells with distinct transcription factor expression-patterns throughout the different phases. PMID:25611738

  6. Full genome sequences and molecular characterization of tick-borne encephalitis virus strains isolated from human patients.

    PubMed

    Formanová, Petra; Černý, Jiří; Bolfíková, Barbora Černá; Valdés, James J; Kozlova, Irina; Dzhioev, Yuri; Růžek, Daniel

    2015-02-01

    Tick-borne encephalitis virus (TBEV) causes tick-borne encephalitis (TBE), one of the most important human neuroinfections across Eurasia. Up to date, only three full genome sequences of human European TBEV isolates are available, mostly due to difficulties with isolation of the virus from human patients. Here we present full genome characterization of an additional five low-passage TBEV strains isolated from human patients with severe forms of TBE. These strains were isolated in 1953 within Central Bohemia in the former Czechoslovakia, and belong to the historically oldest human TBEV isolates in Europe. We demonstrate here that all analyzed isolates are distantly phylogenetically related, indicating that the emergence of TBE in Central Europe was not caused by one predominant strain, but rather a pool of distantly related TBEV strains. Nucleotide identity between individual sequenced TBEV strains ranged from 97.5% to 99.6% and all strains shared large deletions in the 3' non-coding region, which has been recently suggested to be an important determinant of virulence. The number of unique amino acid substitutions varied from 3 to 9 in individual isolates, but no characteristic amino acid substitution typical exclusively for all human TBEV isolates was identified when compared to the isolates from ticks. We did, however, correlate that the exploration of the TBEV envelope glycoprotein by specific antibodies were in close proximity to these unique amino acid substitutions. Taken together, we report here the largest number of patient-derived European TBEV full genome sequences to date and provide a platform for further studies on evolution of TBEV since the first emergence of human TBE in Europe. PMID:25311899

  7. Genetic Characterization of Venezuelan Equine Encephalitis Virus from Bolivia, Ecuador and Peru: Identification of a New Subtype ID Lineage

    PubMed Central

    Aguilar, Patricia V.; Adams, A. Paige; Suárez, Victor; Beingolea, Luis; Vargas, Jorge; Manock, Stephen; Freire, Juan; Espinoza, Willan R.; Felices, Vidal; Diaz, Ana; Liang, Xiaodong; Roca, Yelin; Weaver, Scott C.; Kochel, Tadeusz J.

    2009-01-01

    Venezuelan equine encephalitis virus (VEEV) has been responsible for hundreds of thousands of human and equine cases of severe disease in the Americas. A passive surveillance study was conducted in Peru, Bolivia and Ecuador to determine the arboviral etiology of febrile illness. Patients with suspected viral-associated, acute, undifferentiated febrile illness of <7 days duration were enrolled in the study and blood samples were obtained from each patient and assayed by virus isolation. Demographic and clinical information from each patient was also obtained at the time of voluntary enrollment. In 2005–2007, cases of Venezuelan equine encephalitis (VEE) were diagnosed for the first time in residents of Bolivia; the patients did not report traveling, suggesting endemic circulation of VEEV in Bolivia. In 2001 and 2003, VEE cases were also identified in Ecuador. Since 1993, VEEV has been continuously isolated from patients in Loreto, Peru, and more recently (2005), in Madre de Dios, Peru. We performed phylogenetic analyses with VEEV from Bolivia, Ecuador and Peru and compared their relationships to strains from other parts of South America. We found that VEEV subtype ID Panama/Peru genotype is the predominant one circulating in Peru. We also demonstrated that VEEV subtype ID strains circulating in Ecuador belong to the Colombia/Venezuela genotype and VEEV from Madre de Dios, Peru and Cochabamba, Bolivia belong to a new ID genotype. In summary, we identified a new major lineage of enzootic VEEV subtype ID, information that could aid in the understanding of the emergence and evolution of VEEV in South America. PMID:19753102

  8. Toxicity of saponin isolated from Gymnema sylvestre R. Br. (Asclepiadaceae) against Culex tritaeniorhynchus Giles (Diptera: Culicidae) Japanese encephalitis vector mosquito in India.

    PubMed

    Elumalai, Kupppusamy; Dhanasekaran, Shanmugan; Krishnappa, Kaliamoorthy

    2012-12-01

    To determine the larvicidal activity of various extracts of Gymnema sylvestre against the Japanese Encephalitis vector, Culex tritaeniorynchus in Tamilnadu, India. To identify the active principle present in the promising fraction obtained in Chlorofom:Methanol extract of Fraction 2. The G. sylvestre leaf extracts were tested, employing WHO procedure against fourth instar larvae of C. tritaeniorhynchus and the larval mortalities were recorded at various concentrations (6.25, 12.5, 25.0, 50 and 100 µg/mL); the 24h LC50 values of the G. Sylvestre leaf extracts were determined following Probit analysis. It was noteworthy that treatment level 100 µg/mL exhibited highest mortality rates for the three different crude extracts and was significantly different from the mean mortalities recorded for the other concentrations. The LC50 values of 34.756 µg/mL (24.475-51.41), 31.351 µg/mL (20.634-47.043) and 28.577 µg/mL (25.159-32.308) were calculated for acetone, chloroform and methanol extract with the chi-square values of 10.301, 31.351 and 4.093 respectively. The present investigation proved that G. Sylvestre could be possibly utilized as an important component in the Vector Control Program. PMID:23152320

  9. Spatial and Temporal Variation of Japanese encephalitis Disease and Detection of Disease Hotspots: a Case Study of Gorakhpur District, Uttar Pradesh, India

    NASA Astrophysics Data System (ADS)

    Verma, S.; Gupta, R. D.

    2014-11-01

    In recent times, Japanese Encephalitis (JE) has emerged as a serious public health problem. In India, JE outbreaks were recently reported in Uttar Pradesh, Gorakhpur. The present study presents an approach to use GIS for analyzing the reported cases of JE in the Gorakhpur district based on spatial analysis to bring out the spatial and temporal dynamics of the JE epidemic. The study investigates spatiotemporal pattern of the occurrence of disease and detection of the JE hotspot. Spatial patterns of the JE disease can provide an understanding of geographical changes. Geospatial distribution of the JE disease outbreak is being investigated since 2005 in this study. The JE incidence data for the years 2005 to 2010 is used. The data is then geo-coded at block level. Spatial analysis is used to evaluate autocorrelation in JE distribution and to test the cases that are clustered or dispersed in space. The Inverse Distance Weighting interpolation technique is used to predict the pattern of JE incidence distribution prevalent across the study area. Moran's I Index (Moran's I) statistics is used to evaluate autocorrelation in spatial distribution. The Getis-Ord Gi*(d) is used to identify the disease areas. The results represent spatial disease patterns from 2005 to 2010, depicting spatially clustered patterns with significant differences between the blocks. It is observed that the blocks on the built up areas reported higher incidences.

  10. Short-term effects of floods on Japanese encephalitis in Nanchong, China, 2007-2012: A time-stratified case-crossover study.

    PubMed

    Zhang, Feifei; Liu, Zhidong; Zhang, Caixia; Jiang, Baofa

    2016-09-01

    This time-stratified case-crossover study aimed to quantify the impact of floods on daily Japanese encephalitis (JE) cases from 2007 to 2012 in Nanchong city of Sichuan Province, China. Using conditional logistic regression analysis, we calculated the odds ratios (ORs) and 95% confidence intervals (CIs) at different lagged days, adjusting for daily average temperature (AT) and daily average relative humidity (ARH). A total of 370 JE cases were notified during the study period, with the median patient age being 4.2years. The seasonal pattern of JE cases clustered in July and August during the study period. Floods were significantly associated with an increased number of JE cases from lag 23 to lag 24, with the strongest lag effect at lag 23 (OR=2.00, 95% CI: 1.14-3.52). Similarly, AT and ARH were positively associated with daily JE cases from lag 0 to lag 8 and from lag 0 to lag 9, respectively. Floods, with AT and ARH, can be used to forecast JE outbreaks in the study area. Based on the results of this study, recommendations include undertaking control measures before the number of cases increases, especially for regions with similar geographic, climatic, and socio-economic conditions as those in the study area. PMID:27241207

  11. Further observations on subacute sclerosing encephalitis in adult hamsters: the effects of intranasal infections with Langat virus, measles virus and SSPE-measles virus.

    PubMed Central

    Zlotnik, I.; Grant, D. P.

    1976-01-01

    Passage by i.c. inoculations of suckling hamsters enhanced the virulence for adult hamsters of Langat virus (TP21), neurotropic strain of measles virus (HNT) and SSPE-measles virus (HBS), not only for i.c. infections but also for intranasal instillations. The various viral strains passaged in hamsters showed a great similarity of behaviour including the ability of producing in a proportion of apparently unaffected survivors a subacute sclerosing encephalitis, leading to atrophy of parts of the brain especially the rhinencephalon. When large groups of animals were used for transmission experiments it became obvious that within one week after intranasal exposure, all the hamsters either died or became clinically affected, or did not show signs of disease but developed acute inflammatory brain lessions. tlater on, between 2-6 weeks following inoculations only 90% of hamsters were affected with either overt signs of disease or subacute brain lesions, suggesting that in about 10% of hamsters the initial infection did not progress further and that in these animals the early brain lesions disappeared. Passage levels, irrespective of the virus used, did not influence the total numbers of infected hamsters but showed a significant effect on the mortality in TP21 and HNT infections where the number of dead and clinically affected increased in the higher passes. In these higher passes the number of survivors with subacute brain lesions decreased. In SSPE-measles virus the number of clinically affected hamsters and those surviving but developing brain lesions remained constant throughout. Vacuolated neurons were present in the brains of hamsters that survived one of the above 3 viral infections. They were seen beginning from 6 weeks after infection only in animals that developed subacute sclerosing lesions and were most commonly found in the amygdaloid nuclei and in the pyriform cortex. There was a dramatic increase in the number of brains with vacuolated neurons in hamsters

  12. Novel Indole-2-Carboxamide Compounds Are Potent Broad-Spectrum Antivirals Active against Western Equine Encephalitis Virus In Vivo

    PubMed Central

    Delekta, Phillip C.; Dobry, Craig J.; Sindac, Janice A.; Barraza, Scott J.; Blakely, Pennelope K.; Xiang, Jianming; Kirchhoff, Paul D.; Keep, Richard F.; Irani, David N.; Larsen, Scott D.

    2014-01-01

    ABSTRACT Neurotropic alphaviruses, including western, eastern, and Venezuelan equine encephalitis viruses, cause serious and potentially fatal central nervous system infections in humans for which no currently approved therapies exist. We previously identified a series of thieno[3,2-b]pyrrole derivatives as novel inhibitors of neurotropic alphavirus replication, using a cell-based phenotypic assay (W. Peng et al., J. Infect. Dis. 199:950–957, 2009, doi:http://dx.doi.org/10.1086/597275), and subsequently developed second- and third-generation indole-2-carboxamide derivatives with improved potency, solubility, and metabolic stability (J. A. Sindac et al., J. Med. Chem. 55:3535–3545, 2012, doi:http://dx.doi.org/10.1021/jm300214e; J. A. Sindac et al., J. Med. Chem. 56:9222–9241, 2013, http://dx.doi.org/10.1021/jm401330r). In this report, we describe the antiviral activity of the most promising third-generation lead compound, CCG205432, and closely related analogs CCG206381 and CCG209023. These compounds have half-maximal inhibitory concentrations of ∼1 μM and selectivity indices of >100 in cell-based assays using western equine encephalitis virus replicons. Furthermore, CCG205432 retains similar potency against fully infectious virus in cultured human neuronal cells. These compounds show broad inhibitory activity against a range of RNA viruses in culture, including members of the Togaviridae, Bunyaviridae, Picornaviridae, and Paramyxoviridae families. Although their exact molecular target remains unknown, mechanism-of-action studies reveal that these novel indole-based compounds target a host factor that modulates cap-dependent translation. Finally, we demonstrate that both CCG205432 and CCG209023 dampen clinical disease severity and enhance survival of mice given a lethal western equine encephalitis virus challenge. These studies demonstrate that indole-2-carboxamide compounds are viable candidates for continued preclinical development as inhibitors of

  13. Tick-borne encephalitis in dogs: application of "nested real-time RT-PCR" for intravital virus detection.

    PubMed

    Hekrlová, Alena; Kubíček, Oldfich; Lány, Petr; Rosenbergová, Kateřina; Schánilec, Pavel

    2015-01-01

    Tick-borne encephalitis (TBE) virus is a tick-transmitted virus causing disorders of the nervous system in humans, monkeys, dogs and horses (rarely). At present the detection of TBE infection in dogs is performed by confirmation of seroconversion in paired samples of serum in clinical practice. The intention of the study was the assessment of the possible application of nested real-time RT-PCR for detection of TBE virus in canine blood. The study was carried out in 2011-2012 using samples originating in the Czech Republic, South Moravian region (region with endemic occurrence of TBE). The dogs were randomly selected from the patients visiting the clinic during this time period. Of the total amount of 159 canine blood samples, 20 samples were tested with a PCR-positive result (12.6%). Out of these 20 animals, the neurological clinical symptoms typical of TBE were detected in seven dogs. PCR-positive results were found between March and November. Three dogs were tested with a competitive ELISA-positive result and a "nested real-time RT-PCR"-positive result concurrently. In the group of 159 dogs the value of seroprevalence was found to be 11.3%. PMID:26591386

  14. Identification of host genes leading to West Nile virus encephalitis in mice brain using RNA-seq analysis

    PubMed Central

    Kumar, Mukesh; Belcaid, Mahdi; Nerurkar, Vivek R.

    2016-01-01

    Differential host responses may be critical determinants of distinct pathologies of West Nile virus (WNV) NY99 (pathogenic) and WNV Eg101 (non-pathogenic) strains. We employed RNA-seq technology to analyze global differential gene expression in WNV-infected mice brain and to identify the host cellular factors leading to lethal encephalitis. We identified 1,400 and 278 transcripts, which were differentially expressed after WNV NY99 and WNV Eg101 infections, respectively, and 147 genes were common to infection with both the viruses. Genes that were up-regulated in infection with both the viruses were mainly associated with interferon signaling. Genes associated with inflammation and cell death/apoptosis were only expressed after WNV NY99 infection. We demonstrate that differences in the activation of key pattern recognition receptors resulted in the induction of unique innate immune profiles, which corresponded with the induction of interferon and inflammatory responses. Pathway analysis of differentially expressed genes indicated that after WNV NY99 infection, TREM-1 mediated activation of toll-like receptors leads to the high inflammatory response. In conclusion, we have identified both common and specific responses to WNV NY99 and WNV Eg101 infections as well as genes linked to potential resistance to infection that may be targets for therapeutics. PMID:27211830

  15. Identification of host genes leading to West Nile virus encephalitis in mice brain using RNA-seq analysis.

    PubMed

    Kumar, Mukesh; Belcaid, Mahdi; Nerurkar, Vivek R

    2016-01-01

    Differential host responses may be critical determinants of distinct pathologies of West Nile virus (WNV) NY99 (pathogenic) and WNV Eg101 (non-pathogenic) strains. We employed RNA-seq technology to analyze global differential gene expression in WNV-infected mice brain and to identify the host cellular factors leading to lethal encephalitis. We identified 1,400 and 278 transcripts, which were differentially expressed after WNV NY99 and WNV Eg101 infections, respectively, and 147 genes were common to infection with both the viruses. Genes that were up-regulated in infection with both the viruses were mainly associated with interferon signaling. Genes associated with inflammation and cell death/apoptosis were only expressed after WNV NY99 infection. We demonstrate that differences in the activation of key pattern recognition receptors resulted in the induction of unique innate immune profiles, which corresponded with the induction of interferon and inflammatory responses. Pathway analysis of differentially expressed genes indicated that after WNV NY99 infection, TREM-1 mediated activation of toll-like receptors leads to the high inflammatory response. In conclusion, we have identified both common and specific responses to WNV NY99 and WNV Eg101 infections as well as genes linked to potential resistance to infection that may be targets for therapeutics. PMID:27211830

  16. Three-dimensional architecture of tick-borne encephalitis virus replication sites and trafficking of the replicated RNA.

    PubMed

    Miorin, Lisa; Romero-Brey, Inés; Maiuri, Paolo; Hoppe, Simone; Krijnse-Locker, Jacomine; Bartenschlager, Ralf; Marcello, Alessandro

    2013-06-01

    Flavivirus replication is accompanied by the rearrangement of cellular membranes that may facilitate viral genome replication and protect viral components from host cell responses. The topological organization of viral replication sites and the fate of replicated viral RNA are not fully understood. We exploited electron microscopy to map the organization of tick-borne encephalitis virus (TBEV) replication compartments in infected cells and in cells transfected with a replicon. Under both conditions, 80-nm vesicles were seen within the lumen of the endoplasmic reticulum (ER) that in infected cells also contained virions. By electron tomography, the vesicles appeared as invaginations of the ER membrane, displaying a pore that could enable release of newly synthesized viral RNA into the cytoplasm. To track the fate of TBEV RNA, we took advantage of our recently developed method of viral RNA fluorescent tagging for live-cell imaging combined with bleaching techniques. TBEV RNA was found outside virus-induced vesicles either associated to ER membranes or free to move within a defined area of juxtaposed ER cisternae. From our results, we propose a biologically relevant model of the possible topological organization of flavivirus replication compartments composed of replication vesicles and a confined extravesicular space where replicated viral RNA is retained. Hence, TBEV modifies the ER membrane architecture to provide a protected environment for viral replication and for the maintenance of newly replicated RNA available for subsequent steps of the virus life cycle. PMID:23552408

  17. Experimental Infection of Aedes sollicitans and Aedes taeniorhynchus with Two Chimeric Sindbis/Eastern Equine Encephalitis Virus Vaccine Candidates

    PubMed Central

    Arrigo, Nicole C.; Watts, Douglas M.; Frolov, Ilya; Weaver, Scott C.

    2008-01-01

    Two chimeric vaccine candidates for Eastern equine encephalitis virus (EEEV) were developed by inserting the structural protein genes of either a North American (NA) or South American (SA) EEEV into a Sindbis virus (SINV) backbone. To assess the effect of chimerization on mosquito infectivity, experimental infections of two potential North American bridge vectors of EEEV, Aedes sollicitans and Ae. taeniorhynchus, were attempted. Both species were susceptible to oral infection with all viruses after ingestion of high titer blood meals of ca. 7.0 log10 plaque-forming units/mL. Dissemination rates for SIN/NAEEEV (0 of 56) and SIN/SAEEEV (1 of 54) were low in Ae. taeniorhynchus and no evidence of transmission potential was observed. In contrast, the chimeras disseminated more efficiently in Ae. sollicitans (19 of 68 and 13 of 57, respectively) and were occasionally detected in the saliva of this species. These results indicate that chimerization of the vaccine candidates reduces infectivity. However, its impact on dissemination and potential transmission is mosquito species-specific. PMID:18187790

  18. Antiviral macrophage responses in flavivirus encephalitis.

    PubMed

    Ashhurst, Thomas Myles; Vreden, Caryn van; Munoz-Erazo, Luis; Niewold, Paula; Watabe, Kanami; Terry, Rachael L; Deffrasnes, Celine; Getts, Daniel R; Cole King, Nicholas Jonathan

    2013-11-01

    Mosquito-borne flaviviruses are a major current and emerging threat, affecting millions of people worldwide. Global climate change, combined with increasing proximity of humans to animals and mosquito vectors by expansion into natural habitats, coupled with the increase in international travel, have resulted in significant spread and concomitant increase in the incidence of infection and severe disease. Although neuroinvasive disease has been well described for some viral infections such as Japanese Encephalitis virus (JEV) and West Nile virus (WNV), others such as dengue virus (DENV) have recently displayed an emerging pattern of neuroinvasive disease, distinct from the previously observed, systemically-induced encephalomyelopathy. In this setting, the immune response is a crucial component of host defence, in preventing viral dissemination and invasion of the central nervous system (CNS). However, subversion of the anti-viral activities of macrophages by flaviviruses can facilitate viral replication and spread, enhancing the intensity of immune responses, leading to severe immune-mediated disease which may be further exacerbated during the subsequent infection with some flaviviruses. Furthermore, in the CNS myeloid cells may be responsible for inducing specific inflammatory changes, which can lead to significant pathological damage during encephalitis. The interaction of virus and cells of the myeloid lineage is complex, and this interaction is likely responsible at least in part, for crucial differences between viral clearance and pathology. Recent studies on the role of myeloid cells in innate immunity and viral control, and the mechanisms of evasion and subversion used by flaviviruses are rapidly advancing our understanding of the immunopathological mechanisms involved in flavivirus encephalitis and will lead to the development of therapeutic strategies previously not considered. PMID:24434318

  19. The first detection of the tick-borne encephalitis virus (TBEV) RNA in Dermacentor reticulatus ticks collected from the lowland European bison (Bison bonasus bonasus L.).

    PubMed

    Biernat, Beata; Karbowiak, Grzegorz; Stańczak, Joanna; Masny, Aleksander; Werszko, Joanna

    2016-01-01

    Tick borne encephalitis virus (TBEV) (Flaviviridae, Flavivirus) is the causative agent of tick-borne encephalitis (TBE), a potentially fatal neurological infection. The disease is endemic in a large region in Eurasia, where is transmitted mainly by hard ticks: Ixodes ricinus and I. persulcatus. It is known that also Dermacentor reticulatus is involved in a circulation of TBEV, but the knowledge of its importance in the TBE epidemiology is still insufficient. The Białowieża Primeval Forest is located in eastern Poland and it is a well-known endemic focus of tick-borne encephalitis. The aim of this study was to identify the prevalence of tick-borne encephalitis virus (TBEV) in Dermacentor reticulatus ticks collected from European bison (Bison bonasus bonasus), an important host of hard ticks in the Białowieża Primeval Forest. In the years 2008-2009, a total of 114 adult D. reticulatus ticks were collected from 7 European bison and examined individually for the presence of TBEV RNA using nested RT-PCR assay. Positive results were noted in 18.42% of ticks. This is the first record of TBEV infection in ticks collected from European bison. PMID:26751883

  20. Detection of Israel turkey meningo-encephalitis virus from mosquito (Diptera: Culicidae) and Culicoides (Diptera: Ceratopogonidae) species and its survival in Culex pipiens and Phlebotomus papatasi (Diptera: Phlebotomidae).

    PubMed

    Braverman, Y; Davidson, I; Chizov-Ginzburg, A; Chastel, C

    2003-07-01

    Israel turkey meningo-encephalitis (ITME) virus was detected in pools of Ochlerotatus caspius Pallas and Culicoides imicola Kieffer trapped at a turkey run at Nir David during an outbreak in August 1995. Experimental membrane feeding on a blood ITME suspension showed that Culex pipiens L. became harbored virus for at least 14 d. When Phlebotomus papatasi Scopoli were fed on an infected turkey, they became infected and harbored the virus for at least 7 d. Because Phlebotomines are trapped frequently at turkey runs in Israel, they should be suspected as potential vectors of ITME. PMID:14680120

  1. Tick-Borne Encephalitis Virus Replication, Intracellular Trafficking, and Pathogenicity in Human Intestinal Caco-2 Cell Monolayers

    PubMed Central

    Möller, Lars; Schulzke, Joerg D.; Niedrig, Matthias; Bücker, Roland

    2014-01-01

    Tick-borne encephalitis virus (TBEV) is one of the most important vector-borne viruses in Europe and Asia. Its transmission mainly occurs by the bite of an infected tick. However, consuming milk products from infected livestock animals caused TBEV cases. To better understand TBEV transmission via the alimentary route, we studied viral infection of human intestinal epithelial cells. Caco-2 cells were used to investigate pathological effects of TBEV infection. TBEV-infected Caco-2 monolayers showed morphological changes including cytoskeleton rearrangements and cytoplasmic vacuolization. Ultrastructural analysis revealed dilatation of the rough endoplasmic reticulum and further enlargement to TBEV containing caverns. Caco-2 monolayers maintained an intact epithelial barrier with stable transepithelial electrical resistance (TER) during early stage of infection. Concomitantly, viruses were detected in the basolateral medium, implying a transcytosis pathway. When Caco-2 cells were pre-treated with inhibitors of cellular pathways of endocytosis TBEV cell entry was efficiently blocked, suggesting that actin filaments (Cytochalasin) and microtubules (Nocodazole) are important for PI3K-dependent (LY294002) virus endocytosis. Moreover, experimental fluid uptake assay showed increased intracellular accumulation of FITC-dextran containing vesicles. Immunofluorescence microscopy revealed co-localization of TBEV with early endosome antigen-1 (EEA1) as well as with sorting nexin-5 (SNX5), pointing to macropinocytosis as trafficking mechanism. In the late phase of infection, further evidence was found for translocation of virus via the paracellular pathway. Five days after infection TER was slightly decreased. Epithelial barrier integrity was impaired due to increased epithelial apoptosis, leading to passive viral translocation. These findings illuminate pathomechanisms in TBEV infection of human intestinal epithelial cells and viral transmission via the alimentary route. PMID

  2. Human herpes virus 6 encephalitis in allopurinol-induced hypersensitivity syndrome.

    PubMed

    Masaki, Taro; Fukunaga, Atsushi; Tohyama, Mikiko; Koda, Yoshiyuki; Okuda, Shiho; Maeda, Nobuya; Kanda, Fumio; Yasukawa, Masaki; Hashimoto, Koji; Horikawa, Tatsuya; Ueda, Masato

    2003-01-01

    Hypersensitivity syndrome is one of the most severe forms of drug eruption, and is characterized by a severe, potentially lethal, multiorgan involvement. Recently, reactivation of human herpesvirus 6 (HHV-6) has been suggested to be involved in this syndrome, although the exact role of HHV-6 remains elusive. In addition to exanthem subitum, neurological illnesses, such as infantile febrile illness without rash and encephalitis in immunocompromised patients have been attributed to HHV-6. A 51-year-old man developed a generalized erythematous eruption during treatment with allopurinol. Prednisolone improved his condition, but after the dose of prednisolone was reduced neurological abnormalities such as mental deterioration and positive meningeal signs developed. HHV-6 DNA in his blood by PCR analysis was positive. Furthermore, we detected HHV-6 DNA in the cerebrospinal fluid. The titers of anti-HHV-6-IgG increased during the course. His neurological symptoms gradually improved and no neurological sequelae were noted. Neurological abnormalities associated with hypersensitivity syndrome are very rare. However, the detection of HHV-6 DNA in the cerebrospinal fluid strongly indicates an involvement of reactivated HHV-6 in encephalitis. PMID:12735642

  3. Lymphadenopathy and non-suppurative meningo-encephalitis in calves experimentally infected with bovine immunodeficiency-like virus (FL112).

    PubMed

    Munro, R; Lysons, R; Venables, C; Horigan, M; Jeffrey, M; Dawson, M

    1998-08-01

    In an experiment on bovine immunodeficiency-like virus (BIV), the virological and serological aspects of which were reported in an earlier paper, three groups (A, B and C) of three calves were inoculated subcutaneously with a recently isolated strain (FL112). For group B and group C, the virus was suspended in milk, and for group C (controls) the viral suspension was subjected to pasteurization before inoculation. The calves were killed for necropsy 12 months later. Clinical assessment revealed subtle ataxia in two group A calves, which took the form of an intermittent "shifting" (from one leg to another) lameness, and palpable enlargement of the pre-scapular lymph nodes in one group B animal. At necropsy, haemal lymph nodes (0.1 to 0.5 cm in diameter), occurring singly, were observed in all animals. However, in groups A and B (but not C), enlarged haemal lymph nodes (< or = 2 cm in diameter) were also seen, occurring singly and in chains; and in one group A animal they occurred in grape-like clusters. In groups A and B (but not C), histopathological examination revealed generalized hyperplastic changes in lymph nodes, especially the haemal lymph nodes. This finding was particularly striking in the two clinically ataxic animals from group A, which also showed a non-suppurative meningo-encephalitis; the latter was possibly the cause of the subtle clinical signs. This study supports previous findings on lymphadenopathy resulting from experimental infection with BIV. PMID:9749357

  4. Comparative analysis of immune responses to Russian spring-summer encephalitis and Omsk hemorrhagic fever viruses in mouse models

    PubMed Central

    Tigabu, Bersabeh; Juelich, Terry; Holbrook, Michael R.

    2010-01-01

    Omsk hemorrhagic fever virus (OHFV) and Russian spring-summer encephalitis virus (RSSEV) are tick-borne flaviviruses that have close homology but different pathology and disease outcomes. Previously, we reported that C57BL/6 and BALB/c mice were excellent models to study the pathology and clinical signs of human RSSEV and OHFV infection. In the study described here, we found that RSSEV infection induced robust release of proinflammatory cytokines (IL-1α, IL-1β, IL-6 and TNF-α) and chemokines (MCP-1, MIP-1β, RANTES and KC) in the brain at 9 and 11dpi, together with moderate to low Th1 and Th2 cytokines. In contrast, OHFV infection stimulated an early and prominent induction of IL-1α, TNF-α, IL-12p70, MCP-1, MIP-1α and MIP-1β in the spleen of infected mice. Collectively our data suggest that a differential host response to infection may lead to the alternate disease outcomes seen following OHFV or RSSEV infection. PMID:20875909

  5. Type I interferon induction is correlated with attenuation of a South American eastern equine encephalitis virus strain in mice

    PubMed Central

    Gardner, Christina L.; Yin, Jun; Burke, Crystal W.; Klimstra, William B.; Ryman, Kate D.

    2009-01-01

    North American eastern equine encephalitis virus (NA-EEEV) strains cause high mortality in humans, whereas South American strains (SA-EEEV) are typically avirulent. To clarify mechanisms of SA-EEEV attenuation, we compared mouse-attenuated BeAr436087 SA-EEEV, considered an EEEV vaccine candidate, with mouse-virulent NA-EEEV strain, FL93-939. Although attenuated, BeAr436087 initially replicated more efficiently than FL93-939 in lymphoid and other tissues, inducing systemic IFN-α/β release, whereas FL93-939 induced little. BeAr436087 was more virulent than FL93-939 in IFN-α/β-deficient mice, confirming that type I IFN responses determined attenuation, but the viruses were similarly sensitive to IFN-α/β priming in vitro. Infection with BeAr436087 protected against FL93-939 disease/death, even when given 8 h afterward, suggesting that the environment produced by BeAr436087 infection attenuated FL93-939. We conclude that avoidance of IFN-α/β induction is factor for FL93-939. Furthermore, BeAr436087 could be used for vaccination and therapeutic treatment in the event of exposure to NA-EEEV during a bioterrorism attack. PMID:19539968

  6. Vector Competence and Capacity of Culex erraticus (Diptera: Culicidae) for Eastern Equine Encephalitis Virus in the Southeastern United States.

    PubMed

    Bingham, Andrea M; Burkett-Cadena, Nathan D; Hassan, Hassan K; Unnasch, Thomas R

    2016-03-01

    Field studies of the ecology of eastern equine encephalitis virus (EEEV; family Togaviridae, genus Alphavirus) in the southeastern United States have demonstrated that Culex erraticus (Dyar and Knab) is the most common mosquito at many enzootic sites and is often infected with the virus. However, the competence of Cx. erraticus for EEEV has not been explored in detail. Culex erraticus females were collected from the field and fed upon EEEV-infected chicks. The infected mosquitoes were provided honey for nutrition and to monitor for time to infectiveness. Of the mosquitoes that survived the 14-d postfeeding period, 89% were infected and 84% had evidence of a disseminated infection, though titers were generally low. EEEV was first detected in honey 6 d postinfection and was detected in samples collected from 94% of the mosquitoes with a disseminated infection overall. These data and others were then employed to estimate the relative vectorial capacity of Cx. erraticus at an EEEV enzootic site in Alabama. The vectorial capacity of Cx. erraticus at this site was 44% of Culiseta melanura (Coquillett), the accepted enzootic vector, suggesting Cx. erraticus may play a role in transmitting EEEV in areas where it is abundant and Cs. melanura rare. PMID:26659606

  7. Nipah encephalitis - an update.

    PubMed

    Sherrini, B A; Chong, T T

    2014-08-01

    Between September 1998 to May 1999, Malaysia and Singapore were hit by an outbreak of fatal encephalitis caused by a novel virus from the paramyxovirus family. This virus was subsequently named as Nipah virus, after the Sungei Nipah village in Negeri Sembilan, where the virus was first isolated. The means of transmission was thought to be from bats-topigs and subsequently pigs-to-human. Since 2001, almost yearly outbreak of Nipah encephalitis has been reported from Bangladesh and West Bengal, India. These outbreaks were characterized by direct bats-to-human, and human-to-human spread of infection. Nipah virus shares many similar characteristics to Hendra virus, first isolated in an outbreak of respiratory illness involving horses in Australia in 1994. Because of their homology, a new genus called Henipavirus (Hendra + Nipah) was introduced. Henipavirus infection is a human disease manifesting most often as acute encephalitis (which may be relapsing or late-onset) or pneumonia, with a high mortality rate. Pteropus bats act as reservoir for the virus, which subsequently lead to human spread. Transmission may be from consumption of food contaminated by bats secretion, contact with infected animals, or human-to-human spread. With wide geographical distribution of Pteropus bats, Henipavirus infection has become an important emerging human infection with worldwide implication. PMID:25417957

  8. Replication and transmission of influenza viruses in Japanese quail

    PubMed Central

    Makarova, Natalia V.; Ozaki, Hiroishi; Kida, Hiroshi; Webster, Robert G.; Perez, Daniel R.

    2015-01-01

    Quail have emerged as a potential intermediate host in the spread of avian influenza A viruses in poultry in Hong Kong. To better understand this possible role, we tested the replication and transmission in quail of influenza A viruses of all 15 HA subtypes. Quail supported the replication of at least 14 subtypes. Influenza A viruses replicated predominantly in the respiratory tract. Transmission experiments suggested that perpetuation of avian influenza viruses in quail requires adaptation. Swine influenza viruses were isolated from the respiratory tract of quail at low levels. There was no evidence of human influenza A or B virus replication. Interestingly, a human–avian recombinant containing the surface glycoprotein genes of a quail virus and the internal genes of a human virus replicated and transmitted readily in quail; therefore, quail could function as amplifiers of influenza virus reassortants that have the potential to infect humans and/or other mammalian species. PMID:12788625

  9. Comparison of immune responses of brown-headed cowbird and related blackbirds to West Nile and other mosquito-borne encephalitis viruses

    USGS Publications Warehouse

    Reisen, W.K.; Hahn, D.C.

    2007-01-01

    The rapid geographic spread of West Nile virus (family Flaviviridae, genus Flavivirus, WNV) across the United States has stimulated interest in comparative host infection studies to delineate competent avian hosts critical for viral amplification. We compared the host competence of four taxonomically related blackbird species (Icteridae) after experimental infection with WNV and with two endemic, mosquito-borne encephalitis viruses, western equine encephalomyelitis virus (family Togaviridae, genus Alphavirus, WEEV), and St, Louis encephalitis virus (family Flaviviridae, genus Flavivirus, SLEV). We predicted differences in disease resistance among the blackbird species based on differences in life history, because they differ in geographic range and life history traits that include mating and breeding systems. Differences were observed among the response of these hosts to all three viruses, Red-winged Blackbirds were more susceptible to SLEV than Brewer's Blackbirds, whereas Brewer's Blackbirds were more susceptible to WEEV than Red-winged Blackbirds. In response to WNV infection, cowbirds showed the lowest mean viremias, cleared their infections faster, and showed lower antibody levels than concurrently infected species. Brown-headed Cowbirds also exhibited significantly lower viremia responses after infection with SLEV and WEEV as well as coinfection with WEEV and WNV than concurrently infected icterids. We concluded that cowbirds may be more resistant to infection to both native and introduced viruses because they experience heightened exposure to a variety of pathogens of parenting birds during the course of their parasitic life style.

  10. Utilisation of ISA Reverse Genetics and Large-Scale Random Codon Re-Encoding to Produce Attenuated Strains of Tick-Borne Encephalitis Virus within Days

    PubMed Central

    Aubry, Fabien; Gould, Ernest A.; de Lamballerie, Xavier

    2016-01-01

    Large-scale codon re-encoding is a new method of attenuating RNA viruses. However, the use of infectious clones to generate attenuated viruses has inherent technical problems. We previously developed a bacterium-free reverse genetics protocol, designated ISA, and now combined it with large-scale random codon-re-encoding method to produce attenuated tick-borne encephalitis virus (TBEV), a pathogenic flavivirus which causes febrile illness and encephalitis in humans. We produced wild-type (WT) and two re-encoded TBEVs, containing 273 or 273+284 synonymous mutations in the NS5 and NS5+NS3 coding regions respectively. Both re-encoded viruses were attenuated when compared with WT virus using a laboratory mouse model and the relative level of attenuation increased with the degree of re-encoding. Moreover, all infected animals produced neutralizing antibodies. This novel, rapid and efficient approach to engineering attenuated viruses could potentially expedite the development of safe and effective new-generation live attenuated vaccines. PMID:27548676

  11. Nanoformulation of poly(ethylene glycol) polymerized organic insect repellent by PIT emulsification method and its application for Japanese encephalitis vector control.

    PubMed

    Balaji, A P B; Mishra, Prabhakar; Suresh Kumar, R S; Mukherjee, Amitava; Chandrasekaran, Natarajan

    2015-04-01

    The utilization of increased dosage of insect repellents to overcome mosquito resistance has raised environmental concerns globally. In accord to this, we have formulated an efficacious, water-dispersive, nanometric formulation of a poor water-soluble insect repellent, diethylphenylacetamide (DEPA) by poly(ethylene glycol) (PEG) polymerization followed by PIT emulsification method. The critical micelle concentration of PEG in the spontaneously emulsified conventional DEPA droplets was determined, based on the droplets physical stability. Subjecting them to PIT emulsification yielded monodispersed polymeric nanomicelles of DEPA (Nano DEPA) with hydrodynamic mean diameter of 153.74 nm. The high-resolution scanning and transmission electron microscopic studies revealed the characteristic core-shell structure of micelle. The comparative efficacy of Bulk DEPA and Nano DEPA was evaluated by larvicidal and WHO cone bioassay against the Japanese encephalitis vector Culex tritaeniorhynchus. The median lethal concentrations (48 h) for 3rd instars C. tritaeniorhynchus larvae were found to be 0.416 mg/L for Bulk DEPA and 0.052 mg/L for Nano DEPA, respectively. The median knockdown concentrations (60 min) for the two to three-day-old, sucrose-fed, female adult mosquitoes were 5.372% (v/v) and 3.471% (v/v) for Bulk and Nano DEPA, respectively. Further investigation by histopathological and biochemical studies propound that Nano DEPA exerted better bioefficacy as comparative to its bulk form even at minimal exposure concentrations. Hence, Nano DEPA will serve as an effective alternate in controlling the vector expansion with reduced dosage. PMID:25766922

  12. Eugenol, α-pinene and β-caryophyllene from Plectranthus barbatus essential oil as eco-friendly larvicides against malaria, dengue and Japanese encephalitis mosquito vectors.

    PubMed

    Govindarajan, Marimuthu; Rajeswary, Mohan; Hoti, S L; Bhattacharyya, Atanu; Benelli, Giovanni

    2016-02-01

    Mosquito-borne diseases represent a deadly threat for millions of people worldwide. Eco-friendly mosquitocides are a priority. In Ayurvedic medicine, Plectranthus species have been used to treat heart disease, convulsions, spasmodic pain and painful urination. In this research, we evaluated the acute toxicity of essential oil from Plectranthus barbatus and its major constituents, against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. The chemical composition of P. barbatus essential oil was analyzed by gas chromatography-mass spectroscopy. Nineteen components were identified. Major constituents were eugenol (31.12%), α-pinene (19.38%) and β-caryophyllene (18.42%). Acute toxicity against early third-instar larvae of An. subpictus, Ae. albopictus and Cx. tritaeniorhynchus was investigated. The essential oil had a significant toxic effect against larvae of An. subpictus, Ae. albopictus and Cx. tritaeniorhynchus, with 50% lethal concentration (LC50) values of 84.20, 87.25 and 94.34 μg/ml and 90% lethal concentration (LC90) values of 165.25, 170.56 and 179.58 μg/ml, respectively. Concerning major constituents, eugenol, α-pinene and β-caryophyllene appeared to be most effective against An. subpictus (LC50 = 25.45, 32.09 and 41.66 μg/ml, respectively), followed by Ae. albopictus (LC50 = 28.14, 34.09 and 44.77 μg/ml, respectively) and Cx. tritaeniorhynchus (LC50 = 30.80, 36.75 and 48.17 μg/ml, respectively). Overall, the chance to use metabolites from P. barbatus essential oil against mosquito vectors seems promising, since they are effective at low doses and could be an advantageous alternative to build newer and safer mosquito control tools. PMID:26518773

  13. Viral Etiology of Encephalitis in Children in Southern Vietnam: Results of a One-Year Prospective Descriptive Study

    PubMed Central

    Tan, Le Van; Qui, Phan Tu; Ha, Do Quang; Hue, Nguyen Bach; Bao, Lam Quoi; Cam, Bach Van; Khanh, Truong Huu; Hien, Tran Tinh; Vinh Chau, Nguyen Van; Tram, Tran Tan; Hien, Vo Minh; Nga, Tran Vu Thieu; Schultsz, Constance; Farrar, Jeremy; van Doorn, H. Rogier; de Jong, Menno D.

    2010-01-01

    Background Acute encephalitis is an important and severe disease in children in Vietnam. However, little is known about the etiology while such knowledge is essential for optimal prevention and treatment. To identify viral causes of encephalitis, in 2004 we conducted a one-year descriptive study at Children's Hospital Number One, a referral hospital for children in southern Vietnam including Ho Chi Minh City. Methodology/Principal Findings Children less than 16 years of age presenting with acute encephalitis of presumed viral etiology were enrolled. Diagnostic efforts included viral culture, serology and real time (RT)-PCRs. A confirmed or probable viral causative agent was established in 41% of 194 enrolled patients. The most commonly diagnosed causative agent was Japanese encephalitis virus (n = 50, 26%), followed by enteroviruses (n = 18, 9.3%), dengue virus (n = 9, 4.6%), herpes simplex virus (n = 1), cytomegalovirus (n = 1) and influenza A virus (n = 1). Fifty-seven (29%) children died acutely. Fatal outcome was independently associated with patient age and Glasgow Coma Scale (GCS) on admission. Conclusions/Significance Acute encephalitis in children in southern Vietnam is associated with high mortality. Although the etiology remains unknown in a majority of the patients, the result from the present study may be useful for future design of treatment and prevention strategies of the disease. The recognition of GCS and age as predictive factors may be helpful for clinicians in managing the patient. PMID:21049060

  14. The transstadial persistence of tick-borne encephalitis virus in Dermacentor reticulatus ticks in natural conditions.

    PubMed

    Karbowiak, Grzegorz; Biernat, Beata; Werszko, Joanna; Rychlik, Leszek

    2016-01-01

    There are a number of reports regarding natural infection of Dermacentor reticulatus ticks with TBE virus; however, the transmission mode of TBE virus in this tick population has not been investigated. This study was conducted in Białowieża Primeval Forest, east Poland. Forty fully engorged nymphs of D. reticulatus were sampled from root voles (Microtus oeconomus). Ticks were kept until molting. All ticks were screened for the presence of TBE virus by nested RT-PCR. Three adult ticks were positive for infection with TBE virus. The present study for the first time demonstrates the possibility of transstadial mode of TBEV transmission in D. reticulatus ticks. PMID:26751892

  15. Complete genome sequence of a divergent strain of Japanese yam mosaic virus from China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel strain of Japanese yam mosaic virus (JYMV-CN) was identified in a yam plant with foliar mottle symptoms in China. The complete genomic sequence of JYMV-CN was determined. Its genomic sequence of 9701 nucleotides encodes a polyprotein of 3247 amino acids. Its organization was virtually identi...

  16. Venezuelan Equine Encephalitis Virus Replicon Particles Encoding Respiratory Syncytial Virus Surface Glycoproteins Induce Protective Mucosal Responses in Mice and Cotton Rats▿

    PubMed Central

    Mok, Hoyin; Lee, Sujin; Utley, Thomas J.; Shepherd, Bryan E.; Polosukhin, Vasiliy V.; Collier, Martha L.; Davis, Nancy L.; Johnston, Robert E.; Crowe, James E.

    2007-01-01

    Respiratory syncytial virus (RSV) is an important viral pathogen that causes severe lower respiratory tract infection in infants, the elderly, and immunocompromised individuals. There are no licensed RSV vaccines to date. To prevent RSV infection, immune responses in both the upper and lower respiratory tracts are required. Previously, immunization with Venezuelan equine encephalitis virus replicon particles (VRPs) demonstrated effectiveness in inducing mucosal protection against various pathogens. In this study, we developed VRPs encoding RSV fusion (F) or attachment (G) glycoproteins and evaluated the immunogenicity and efficacy of these vaccine candidates in mice and cotton rats. VRPs, when administered intranasally, induced surface glycoprotein-specific virus neutralizing antibodies in serum and immunoglobulin A (IgA) antibodies in secretions at the respiratory mucosa. In addition, fusion protein-encoding VRPs induced gamma interferon (IFN-γ)-secreting T cells in the lungs and spleen, as measured by reaction with an H-2Kd-restricted CD8+ T-cell epitope. In animals vaccinated with F protein VRPs, challenge virus replication was reduced below the level of detection in both the upper and lower respiratory tracts following intranasal RSV challenge, while in those vaccinated with G protein VRPs, challenge virus was detected in the upper but not the lower respiratory tract. Close examination of histopathology of the lungs of vaccinated animals following RSV challenge revealed no enhanced inflammation. Immunization with VRPs induced balanced Th1/Th2 immune responses, as measured by the cytokine profile in the lungs and antibody isotype of the humoral immune response. These results represent an important first step toward the use of VRPs encoding RSV proteins as a prophylactic vaccine for RSV. PMID:17928349

  17. Vector-Host Interactions of Culiseta melanura in a Focus of Eastern Equine Encephalitis Virus Activity in Southeastern Virginia.

    PubMed

    Molaei, Goudarz; Armstrong, Philip M; Abadam, Charles F; Akaratovic, Karen I; Kiser, Jay P; Andreadis, Theodore G

    2015-01-01

    Eastern equine encephalitis virus (EEEV) causes a highly pathogenic mosquito-borne zoonosis that is responsible for sporadic outbreaks of severe illness in humans and equines in the eastern USA. Culiseta (Cs.) melanura is the primary vector of EEEV in most geographic regions but its feeding patterns on specific avian and mammalian hosts are largely unknown in the mid-Atlantic region. The objectives of our study were to: 1) identify avian hosts of Cs. melanura and evaluate their potential role in enzootic amplification of EEEV, 2) assess spatial and temporal patterns of virus activity during a season of intense virus transmission, and 3) investigate the potential role of Cs. melanura in epidemic/epizootic transmission of EEEV to humans and equines. Accordingly, we collected mosquitoes at 55 sites in Suffolk, Virginia in 2013, and identified the source of blood meals in engorged mosquitoes by nucleotide sequencing PCR products of the mitochondrial cytochrome b gene. We also examined field-collected mosquitoes for evidence of infection with EEEV using Vector Test, cell culture, and PCR. Analysis of 188 engorged Cs. melanura sampled from April through October 2013 indicated that 95.2%, 4.3%, and 0.5% obtained blood meals from avian, mammalian, and reptilian hosts, respectively. American Robin was the most frequently identified host for Cs. melanura (42.6% of blood meals) followed by Northern Cardinal (16.0%), European Starling (11.2%), Carolina Wren (4.3%), and Common Grackle (4.3%). EEEV was detected in 106 mosquito pools of Cs. melanura, and the number of virus positive pools peaked in late July with 22 positive pools and a Maximum Likelihood Estimation (MLE) infection rate of 4.46 per 1,000 mosquitoes. Our findings highlight the importance of Cs. melanura as a regional EEEV vector based on frequent feeding on virus-competent bird species. A small proportion of blood meals acquired from mammalian hosts suggests the possibility that this species may occasionally

  18. Vector-Host Interactions of Culiseta melanura in a Focus of Eastern Equine Encephalitis Virus Activity in Southeastern Virginia

    PubMed Central

    Molaei, Goudarz; Armstrong, Philip M.; Abadam, Charles F.; Akaratovic, Karen I.; Kiser, Jay P.; Andreadis, Theodore G.

    2015-01-01

    Eastern equine encephalitis virus (EEEV) causes a highly pathogenic mosquito-borne zoonosis that is responsible for sporadic outbreaks of severe illness in humans and equines in the eastern USA. Culiseta (Cs.) melanura is the primary vector of EEEV in most geographic regions but its feeding patterns on specific avian and mammalian hosts are largely unknown in the mid-Atlantic region. The objectives of our study were to: 1) identify avian hosts of Cs. melanura and evaluate their potential role in enzootic amplification of EEEV, 2) assess spatial and temporal patterns of virus activity during a season of intense virus transmission, and 3) investigate the potential role of Cs. melanura in epidemic/epizootic transmission of EEEV to humans and equines. Accordingly, we collected mosquitoes at 55 sites in Suffolk, Virginia in 2013, and identified the source of blood meals in engorged mosquitoes by nucleotide sequencing PCR products of the mitochondrial cytochrome b gene. We also examined field-collected mosquitoes for evidence of infection with EEEV using Vector Test, cell culture, and PCR. Analysis of 188 engorged Cs. melanura sampled from April through October 2013 indicated that 95.2%, 4.3%, and 0.5% obtained blood meals from avian, mammalian, and reptilian hosts, respectively. American Robin was the most frequently identified host for Cs. melanura (42.6% of blood meals) followed by Northern Cardinal (16.0%), European Starling (11.2%), Carolina Wren (4.3%), and Common Grackle (4.3%). EEEV was detected in 106 mosquito pools of Cs. melanura, and the number of virus positive pools peaked in late July with 22 positive pools and a Maximum Likelihood Estimation (MLE) infection rate of 4.46 per 1,000 mosquitoes. Our findings highlight the importance of Cs. melanura as a regional EEEV vector based on frequent feeding on virus-competent bird species. A small proportion of blood meals acquired from mammalian hosts suggests the possibility that this species may occasionally

  19. West Nile Virus Population Structure, Injury, and Interferon-Stimulated Gene Expression in the Brain From a Fatal Case of Encephalitis

    PubMed Central

    Grubaugh, Nathan D.; Massey, Aaron; Shives, Katherine D.; Stenglein, Mark D.; Ebel, Gregory D.; Beckham, J. David

    2016-01-01

    Background. West Nile virus (WNV) infection in humans can result in severe, acute encephalitis typically involving subcortical gray matter brain regions. West Nile virus replication within specific human brain regions from a human case of acute encephalitis has not been studied. Methods. We describe a fatal case of WNV encephalitis in which we obtained tissue from specific brain regions at autopsy to evaluate viral-host interactions using next-generation sequencing and immunohistochemistry analysis. Results. We found that WNV populations in the injured subcortical brain regions exhibited increased amino acid variation and increased expression of specific interferon genes compared with cortical tissues despite similar viral burden. Conclusions. These observational, patient-based data suggest that neuronal injury and the strength of viral selection pressure may be associated with the level of the innate immune responses. Further studies in human and animal models evaluating the role of innate immune responses on injury patterns and viral selection pressure are needed. PMID:26730392

  20. Seroprevalence of Borrelia burgdorferi sensu lato and tick-borne encephalitis virus in zoo animal species in the Czech Republic.

    PubMed

    Sirmarová, Jana; Tichá, Lucie; Golovchenko, Marina; Salát, Jiří; Grubhoffer, Libor; Rudenko, Nataliia; Nowotny, Norbert; Růžek, Daniel

    2014-09-01

    This study was conducted to evaluate the prevalence of antibodies against Borrelia bugdorferi (Bb) s.l. and tick-borne encephalitis virus (TBEV) in zoo animals in the Czech Republic. We collected 133 serum samples from 69 animal species from 5 zoos located in different parts of the country. The samples were obtained from even-toed ungulates (n=78; 42 species), odd-toed ungulates (n=32; 11 species), carnivores (n=13; 9 species), primates (n=2, 2 species), birds (n=3; 2 species), and reptiles (n=5; 3 species). A high antibody prevalence (60%) was observed for Bb s.l. On the other hand, only two animals had TBEV-specific antibodies: a markhor (Capra falconeri) and a reindeer (Rangifer tarandus), both from the same zoo, located in an area endemic for TBEV. Both of these animals were also positive for Bb s.l. antibodies. Our results indicate that a high number of animal species in the Czech zoos were exposed to Bb s.l. and that TBEV infection occurred at least in one of the investigated zoos. Considering the pathogenic potential of these two tick-borne pathogens, clinical and serological monitoring should be continued, and therapeutic and preventive measures should be taken when necessary. PMID:24889036

  1. St. Louis Encephalitis virus mosquito vectors dynamics in three different environments in relation to remotely sensed environmental conditions.

    PubMed

    Batallán, Gonzalo P; Estallo, Elizabet L; Flores, Fernando S; Sartor, Paolo; Contigiani, Marta S; Almirón, Walter R

    2015-06-01

    In Argentina the St. Louis Encephalitis virus (SLEV) is an endemic and widely distributed pathogen transmitted by the cosmopolitan mosquito Culex quinquefasciatus. During two outbreaks in Córdoba city, in 2005 and 2010, Culex interfor was also found infected, but its role as vector of SLEV is poorly known. This mosquito species is distributed from central Argentina to southern Brazil. The primary aim of this study was to analyze the population dynamic of Cx. interfor and Cx. quinquefasciatus in three different environments (urban, suburban and non-urban) in relation to remotely sensed environmental data for vegetation (NDVI and NDWI) and temperature (brightness temperature). Cx. quinquefasciatus and Cx. interfor were found at the three sampled sites, being both the most abundant Culex species, with peaks in early and midsummer. Temporal distribution patterns of both mosquito species were highly correlated in a non-urban area of high SLEV risk transmission. Cx. quinquefasciatus and Cx. interfor were associated with the most urbanized site and the non-urban environment, respectively; high significant correlations were detected between vegetation indices and abundance of both mosquito species confirming these associations. These data provide a foundation for building density maps of these two SLEV mosquito vectors using remotely sensed data to help inform vector control programs. PMID:25792419

  2. Estimation of Dispersal Distances of Culex erraticus in a Focus of Eastern Equine Encephalitis Virus in the Southeastern United States

    PubMed Central

    Estep, Laura K.; Burkett-Cadena, Nathan D.; Hill, Geoffrey E.; Unnasch, Robert S.; Unnasch, Thomas R.

    2011-01-01

    Patterns of mosquito dispersal are important for predicting the risk of transmission of mosquito-borne pathogens to vertebrate hosts. We studied dispersal behavior of Culex erraticus (Dyar & Knab), a potentially significant vector of eastern equine encephalitis virus (EEEV) that is often associated with foci of this pathogen in the southeastern United States. Using data on the relative density of resting adult female Cx. erraticus around known emergence sites in Tuskegee National Forest, Alabama, we developed a model for the exponential decay of the relative density of adult mosquitoes with distance from larval habitats through parameterization of dispersal kernels. The mean and 99th percentile of dispersal distance for Cx. erraticus estimated from this model were 0.97 and 3.21 km per gonotrophic cycle, respectively. Parameterized dispersal kernels and estimates of the upper percentiles of dispersal distance of this species can potentially be used to predict EEEV infection risk in areas surrounding the Tuskegee National Forest focus in the event of an EEEV outbreak. The model that we develop for estimating the dispersal distance of Cx. erraticus from collections of adult mosquitoes could be applicable to other mosquito species that emerge from discrete larval sites. PMID:21175044

  3. [Genetic diversity of the tick-borne encephalitis virus in Ixodes persulcatus ticks in northeastern European Russia].

    PubMed

    Mikriukova, T P; Chausov, E V; Konovalova, S N; Kononova, Iu V; Protopopova, E V; Kartashov, M Iu; Trnovoĭ, V A; Glushkova, L I; Korabel'nikov, I V; Egorova, I Iu; Loktev, V B

    2014-01-01

    The genetic diversity of the tick-borne encephalitis virus (TBEV) in the PCR-positive Taiga ticks collected in the Republic of Komi in 2010 was evaluated. The analyses of nucleotide sequences of the 5'-NCR fragments of viral genome from ticks had shown that 13 isolates of TBEV from 16 sequencing variants were represented by the highly pathogenic Far Eastern genotype of the TBEV and only 3 isolates were identified as the Siberian genotype of TBEV. The nucleotide sequences of 5'-NCR of viral genome strongly varied variable in individual ticks. Variability for the A1 element has been observed in all the tested samples, and for elements C1, B2, CS B--in more than 50%. A2 element and ATG codon of the 5'-NCR remained completely conservative. Computer simulation of conformations of the 5'-NCR of TBEV genome demonstrated the possibility of significant changes of the spatial structure of the 5'-NCR of viral genome in individual taiga ticks. The obtained data confirm the hypothesis that the variability in the 5'-NCR of TBEV genome can be crucial for efficient replication of TBEV in different hosts. PMID:25272463

  4. Detection of novel kobu-like viruses in Japanese black cattle in Japan

    PubMed Central

    OTOMARU, Konosuke; NAOI, Yuki; HAGA, Kei; OMATSU, Tsutomu; UTO, Takehiko; KOIZUMI, Motoya; MASUDA, Tsuneyuki; YAMASATO, Hiroshi; TAKAI, Hikaru; AOKI, Hiroshi; TSUCHIAKA, Shinobu; SANO, Kaori; OKAZAKI, Sachiko; KATAYAMA, Yukie; OBA, Mami; FURUYA, Tetsuya; SHIRAI, Junsuke; KATAYAMA, Kazuhiko; MIZUTANI, Tetsuya; NAGAI, Makoto

    2015-01-01

    During surveillance for bovine diarrhea of unknown causes in Japanese black cattle in Kagoshima Prefecture, Japan, we found two types of novel kobu-like viruses in fecal samples of calves. Sequence analyses revealed that