In this review, we mainly focus on zoonotic encephalitides caused by arthropod-borne viruses (arboviruses) of the families Flaviviridae (genus Flavivirus) and Togaviridae (genus Alphavirus) that are important in both humans and domestic animals. Specifically, we will focus on alphaviruses (Eastern equine encephalitis virus, Western equine encephalitis virus, Venezuelan equine encephalitis virus) and flaviviruses (Japanese encephalitis virus and West Nile virus). Most of these viruses were originally found in tropical regions such as Africa and South America or in some regions in Asia. However, they have dispersed widely and currently cause diseases around the world. Global warming, increasing urbanization and population size in tropical regions, faster transportation and rapid spread of arthropod vectors contribute in continuous spreading of arboviruses into new geographic areas causing reemerging or resurging diseases. Most of the reemerging arboviruses also have emerged as zoonotic disease agents and created major public health issues and disease epidemics.
Africa ; Alphavirus* ; Animals, Domestic ; Arboviruses* ; Arthropod Vectors ; Asia ; Encephalitis ; Encephalitis Virus, Venezuelan Equine ; Encephalitis Virus, Western Equine ; Encephalitis Viruses ; Encephalomyelitis, Equine ; Epidemiology* ; Flaviviridae ; Flavivirus* ; Global Warming ; Humans ; Population Density ; Public Health ; South America ; Togaviridae ; Transportation ; Urbanization ; Zoonoses

Alphavirus Infections ; epidemiology ; Chikungunya virus ; Humans

Alphavirus Infections ; diagnosis ; epidemiology ; virology ; Animals ; Chikungunya Fever ; Chikungunya virus ; genetics ; isolation & purification ; physiology ; Humans ; Viral Proteins ; genetics ; metabolism

In September – December 2001 period, from 4987 female Culex mosquitoes collected in Cat Que commune, Hoai Duc district, Ha Tay province, 4 viral species were isolated by clone C6/36 cells of Vero and Aedes albopictus. Among them, 2 species were alpha virus, 01VN61 virus was isolated from Culex tritaeniorhynchus and 01VN62 virus from Culex gelidus, both strains were adapted to 1-2 days age mice. By sequencing technique on E1 gene and 3 NCR gene area, 01VN62 virus was identified as Safiyama virus, a virus of alpha virus
Alphavirus ; Culicidae ; Culex

The incidence of chikungunya infection in Singapore has been on the rise since the first reported case in 2006. Acute polyarthritis, a common manifestation among affected patients, may precede fever and present with debilitating arthritis to rheumatologists, orthopaedists, internists and primary care physicians. The diagnosis of chikungunya infection requires careful history taking and a high index of suspicion, with supporting evidence from the reverse transcription-polymerase chain reaction or the chikungunya IgM serology test. Treatment of chikungunya arthritis usually involves non-steroidal anti-inflammatory drugs. Rarely, polyarthritis in chikungunya may persist even after resolution of the acute infection, necessitating treatment with disease-modifying anti-rheumatic drugs. In this article, we present the different manifestations of chikungunya arthritis in our local setting and review the literature.
Aged ; Alphavirus Infections ; complications ; Anti-Inflammatory Agents, Non-Steroidal ; therapeutic use ; Arthritis ; drug therapy ; virology ; Chikungunya Fever ; Chikungunya virus ; Female ; Humans ; Male ; Middle Aged

Various new technologies have been applied for developing vaccines against various animal diseases. Virus-like particle (VLP) vaccine technology was used for manufacturing the porcine circovirus type 2 and RNA particle vaccines based on an alphavirus vector for porcine epidemic diarrhea (PED). Although VLP is classified as a killed-virus vaccine, because its structure is similar to the original virus, it can induce long-term and cell-mediated immunity. The RNA particle vaccine used a Venezuela equine encephalitis (VEE) virus gene as a vector. The VEE virus partial gene can be substituted with the PED virus spike gene. Recombinant vaccines can be produced by substitution of the target gene in the VEE vector. Both of these new vaccine technologies made it possible to control the infectious disease efficiently in a relatively short time.
Alphavirus ; Animal Diseases ; Animals* ; Circovirus ; Communicable Diseases ; Diarrhea ; Encephalitis Virus, Venezuelan Equine ; Encephalomyelitis, Equine ; Immunity, Cellular ; Porcine epidemic diarrhea virus ; RNA ; Vaccines ; Vaccines, Synthetic ; Vaccines, Virus-Like Particle ; Venezuela

PURPOSE: Chikungunya virus (CHIKV) causes endemic or epidemic outbreaks of CHIKV fever, which is a mosquitoe-transmitted viral disease in Africa, India, South-East Asia, and recently Southern Europe. Currently, serological diagnostic tests such as hemagglutination inhibition test (HI test), in-house IgM capture enzyme-linked immunosorbent assays (ELISA), and indirect immunofluorescence test were used for diagnosis of chikungunya fever, which are based on whole virus antigens. MATERIALS AND METHODS: CHIKV E1, and E2 envelope proteins for the CHIKV-specific serodiagnostic reagents for chikungunya fever were expressed in baculovirus expression system. The seroreactivity of recombinant CHIKV E1 and E2 envelope proteins were evaluated using sera panels of patients from Laboratoire Marcel Merieux by indirect IgM capture ELISA. RESULTS: The recombinant CHIKV E1 and E2 envelope protein showed sensitivity of 77.5% and 90%, respectively. The specificities of both CHIKV E1 and E2 envelope proteins were 100%. CONCLUSION: The recombinant CHIKV E1 and E2 envelope proteins could be a useful diagnostic reagent for CHIKV infection.
Alphavirus Infections/*diagnosis ; Animals ; Baculoviridae/genetics/metabolism ; Cells, Cultured ; Chikungunya virus/genetics ; Cloning, Molecular ; Enzyme-Linked Immunosorbent Assay/methods ; Recombinant Proteins/immunology ; Sensitivity and Specificity ; Serologic Tests/*methods ; Viral Envelope Proteins/*immunology

To construct vector system of XJ-160 virus, a Sindbis virus isolated in China, recombinant vector pBRepXJ together with its helper plasmid pBR-H were derived from XJ-160 viral infectious clone pBR-XJ160 by overlap-PCR. To quantitatively and qualitatively verify the function of the replicon system, recombinant plasmids pSinRep-EGFP, pBRepXJ-EGFP, pSinRep-R and pBRepXJ-R were constructed by cloning report genes of enhanced green fluorescent protein (EGFP) or Renilla luciferase (R. luc) into pBRepXJ or pSinRep5, a commercial Sindbis vector. And in Vitro-synthesized RNA from expression vectors were electroporated into BHK-21 cells. The results indicated that the replicon vector system was capable of self-replicating in host cell, and the expression efficiency of heterologous genes corresponded with that of the commercial Sindbis vector (pSinRep5). Our study laid the basis for developing alphavirus vector system with Chinese intellectual property.
Alphavirus Infections ; genetics ; Cloning, Molecular ; DNA, Complementary ; analysis ; genetics ; Genetic Vectors ; Genome, Viral ; Replicon ; genetics ; Sindbis Virus ; genetics ; Virus Replication ; physiology

OBJECTIVETo investigate the effect of Lead (Pb) acetate exposure on Semliki forest virus (SFV) pathogenesis in mice.

METHODSDifferent doses (62.5, 125, 250 and 500 mg/Kg body weight) of Pb dissolved in normal saline were given to mice by oral intubation in a sub-acute (28 days) and sub-chronic (90 days) regimen followed by SFV infection. Morbidity, mortality, clinical symptoms, mean survival time (MST), changes in body and organ weight, accumulation of lead in soft tissues, virus titre in brain and histopathological alterations were compared between lead exposed and infected groups.

RESULTSEarly appearance of virus symptoms, increased mortality, decreased MST, enhanced SFV titre and greater tissue damage were observed in lead exposed-SFV-infected mice.

CONCLUSIONPre-exposure to lead increases the susceptibility of mice towards SFV infection. Further studies are suggested in view of the persistence of lead in the environment and the possibility of infection by microbial pathogens.

Alphavirus Infections ; etiology ; veterinary ; Animals ; Brain ; pathology ; Dose-Response Relationship, Drug ; Kidney ; pathology ; Lead ; administration & dosage ; toxicity ; Liver ; pathology ; Mice ; Semliki forest virus ; pathogenicity

BACKGROUNDTo develop a rapid, specific and sensitive method for detecting Sindbis virus (SINV) with SYBR GREEN I real time PCR.

METHODSTotal RNA of strains of Sindbis virus and a related virus were extracted and reverse transcribed to cDNAs. With the cDNAs as template, the SYBR GREEN I real time PCR assay was developed and optimized on ABI 7300 apparatus for specific-detection of Sindbis virus, and the sensitivity, specificity and reproducibility were evaluated.

RESULTSFor the PCR, 55 degrees C was chosen as the optimal anneal temperature and 0.5 micromol/L as the optimal primer concentration. Using this method, all the selected SINV were detected as positive, while the results of control arboviruses such as Geta virus, Japanese encephalitis virus (JEV), Batai virus, Seadornavirus Orbiviruses and synthesized WEEV cDNA were negative. With this system, 0.1 PFU/ml SINV cDNA could be detected; The sensitivity of this assay was about 100 times higher than standard RT-PCR. All the results were reproducible within two compatible tests, and the stability of the detection system was very good. The test results of simulated infection human serum samples showed that human serum had no obvious interference with this system. With this system, 6 of 151 clinical samples with unknown fever or encephalitis were determined as positive.

CONCLUSIONThe developed SYBR GREEN I real time PCR assay for detecting Sindbis virus was highly sensitive, specific and showed a good reproducibility and stability. It is our belief that the present method can be further used in clinic sample to verify its stringency.

Alphavirus Infections ; diagnosis ; virology ; DNA, Complementary ; chemistry ; genetics ; Organic Chemicals ; chemistry ; RNA, Viral ; genetics ; isolation & purification ; Reproducibility of Results ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Sensitivity and Specificity ; Sindbis Virus ; genetics