To investigate the infection status and the spatial distribution of Tahyna virus infection among unknown fever cases in Xinjiang, China. Sera samples of unknown fever cases from Kashi in southern Xin-jiang and Yili in northern Xinjiang were tested against Tahyna virus by IFA. Partial positive cases were tested against Tahyna virus/Snowshoe hare virus/Inkoo virus parrelled. Finally, 742 sera samples of unknown fever cases were collected from Kashi, Southern Xinjiang in 2007-2008, the positive rate of IgM antibody against Tahyna virus was 5.3%, the positive rate of IgG antibody against Tahyna virus was 18.3%. 222 sera samples of unknown fever cases were collected from Yili, Northern Xinjiang in 2008, no positive case of IgM antibody against Tahyna was found. 10 cases showed antibody neutralization against Tahyna virus by plaque reduction neutralization test. Our results demonstrate that there is current infection and past infection of Tahyna virus among Southern Xinjiang residents.
Adolescent ; Adult ; Antibodies, Viral ; blood ; Child ; Child, Preschool ; China ; epidemiology ; Encephalitis Virus, California ; immunology ; physiology ; Encephalitis, California ; blood ; epidemiology ; virology ; Female ; Fever ; blood ; epidemiology ; virology ; Humans ; Immunoglobulin M ; blood ; Infant ; Male ; Middle Aged ; Young Adult

A real-time RT-PCR (RT-qPCR) assay for the detection of Tahyna virus was developed to monitor Tahyna virus infection in field-collected vector mosquito samples. The targets selected for the assay were S segment sequences encoding the nucleocapsid protein from the Tahyna virus. Primers and probes were selected in conserved regions by aligning genetic sequences from various Tahyna virus strains available from GenBank. The sensitivity of the RT-qPCR approach was compared to that of a standard plaque assay in BHK cells. RT-qPCR assay can detect 4.8 PFU of titrated Tahyna virus. Assay specificities were determined by testing a battery of arboviruses, including representative strains of Tahyna virus and other arthropod-borne viruses from China. Seven strains of Tahyna virus were confirmed as positive; the other seven species of arboviruses could not be detected by RT-qPCR. Additionally, the assay was used to detect Tahyna viral RNA in pooled mosquito samples. The RT-qPCR assay detected Tahyna virus in a sensitive, specific, and rapid manner; these findings support the use of the assay in viral surveillance.
Animals ; Culicidae ; virology ; Encephalitis Virus, California ; isolation & purification ; Real-Time Polymerase Chain Reaction ; methods ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Sensitivity and Specificity

In 2006, the first Chinese Tahyna virus isolate (XJ0625) was obtained in Xinjiang province and human infection were found in the same region. In this study, cell culture, animal experiments, electron microscopy, immunofluorescence assay and cross neutralization tests were performed to see the cell susceptibility, animal pathogenicity, morphology and antigenic and other biological characteristics of XJ0625. In addition, molecular biology software was used to analyze the characteristics of molecular evolution. The results showed that BHK-21 cell line was susceptible to XJ0625 and the virus was lethal to suckling mice when injected by intracranial ways. Similar to the other Bunyavirus, Tahyna virus is spherical enveloped virus under electron microscopy. XJ0625 infected cells showed strong fluorescent signal and could be neutralized by immune asities fluid with immnity to protype Tahyna virus Bardos 92. The sequence of the S and M segments showed 91.8% and 81.9% homology with Bardos 92.
Animals ; Cell Line ; China ; Encephalitis Virus, California ; genetics ; isolation & purification ; physiology ; Evolution, Molecular ; Female ; Fluorescent Antibody Technique ; Mice ; Nervous System ; virology ; Phylogeny ; Polymerase Chain Reaction ; Sequence Analysis, DNA

Enterovirus 71(EV71), like polioviruses, invades the central nervous system to give rise to aseptic meningitis, encephalitis or myelitis. EV71 was first isolated in California in 1969 from a 9-month- old infant with encephalitis. Since then it has been isolated from the brain of children who died of encephalitis and from feces of patients with meningitis, encephalitis or paralysis. Related strains have been isolated from outbreaks of similar diseases in Australia, Sweden, Bulgaria and Hungary. We have experienced polio-like encephalomyelitis in a 3-month-old girl. Initial brain MR imaging showed tissue destruction in the bilateral posterior portions of the medulla oblongata and the bilateral anterior horns of cervical spinal cord from C3 to C6 level. Follow-up MR imaging was performed 3 months later, which showed minimal residual change on the anterior horn of the cervical spinal cord at C4 level only. This report deals with rare polio-like encephalomyelitis associated with EV71 and discusses its diagnosis and management. Brain stem and cervical spinal cord involvement are characteristic findings of EV encephalomyelitis.
Animals ; Australia ; Brain ; Brain Stem ; Bulgaria ; California ; Central Nervous System ; Child ; Diagnosis ; Disease Outbreaks ; Encephalitis ; Encephalomyelitis* ; Enterovirus* ; Feces ; Female ; Follow-Up Studies ; Horns ; Humans ; Hungary ; Infant ; Magnetic Resonance Imaging ; Medulla Oblongata ; Meningitis ; Meningitis, Aseptic ; Myelitis ; Paralysis ; Poliovirus ; Spinal Cord ; Sweden