ABSTRACT
In 2009, hepatitis E virus was first detected in wild rats ( Rattus norvegicus) in Germany and was designated as rat hepatitis E virus (rat HEV). Since then, rat HEV has been detected in various murine rodents in many geographic regions. The potential of rat HEV to infect human has been ignored as the viral genomic nucleotide sequences of rat HEV and the HEV strains of human sources are only about 50%-56% identical. Recently, a few clinical hepatitis E cases with chronic or acute rat HEV infection have been reported and raised many concerns. Here, advances in studies of the prevalence of rat HEV in animals and the clinical hepatitis E cases caused by rat HEV were reviewed.
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Currently, hepatitis E virus (HEV) infection is diagnosed mainly by the detection of HEV-specific IgM/IgG or HEV RNA. In recent years, the method for detecting HEV antigen (HEV-Ag) has been developed based on the study of the structure and immunity of HEV virion protein. This article reviewed the development of ELISA for HEV-Ag detection and the significance and application of HEV-Ag detection in the diagnosis of HEV infection.
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Zika virus (ZIKV) was first isolated in 1947. It is known to circulate mainly in tropical areas and can be transmitted through Aedes mosquitoes. In 2015, an outbreak of ZIKV began in Brazil and then spread rapidly to the Latin Americans and Caribbean. Accumulating evidence indicates that there are associations between ZIKV infection and human nervous disorders, such as the occurrence of microcephaly in neonates and Guillain-Barré syndrome in adults. The current ZIKV outbreak has been declared a public health emergency of international concern. Here, we review the virological features, transmission and epide-miological characteristics of ZIKV and the clinical featrues and prevention of ZIKV infection.
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Objective To sequence and analyze the full-length genome of one HEV strain,W2-1 isolated from a sporadic hepatitis E patient hospitalized in 1999 in Xinjiang,China.Methods Nested RT-PCR assays with 4 sets primers were used to amplify the entire genome.The PCR products were purified and sequenced.The full-length genome was acquired by assembling the fragmental sequences using the DNAstar 5.01 software.The genome of W2-1 was analyzed by comparing with the reference HEVs from GenBank.Results The complete genome of W2-1 is 7212 nt in length,including three open reading frames (ORF1-3) with 5079,1980 and 345 nt respectively,27 nt 5'UTR and 83 nt 3'UTR,and a 3' poly A tail.Phylogenetic analysis based on full-length genome showed that W2-1 belonged to genotype 1,subtype 1b.W2-1 had high homology with the HEV strains isolated in the large hepatitis E epidemic in Xinjiang in 1987-1989,sharing 97.2％-98.5％ nucleotide identity in the full length genome.W2-1 also showed high homology with 1b strains isolated in China after 2000,with 97.6％-99.2％ nucleotide identity.The specific amino acid sites in ORF1-3 proteins that distinct between genotype 1 HEV and the potential zoonotic strains did not change in W2-1.Conclusion W2-1 belongs to subtype 1b.The study indicates subtype 1b HEV has been circulating in China in a long period after hepatitis E outbreak in Xinjiang in 1986-1989.The amino acids of ORF1-3 of subtype 1b are conserved.
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Objective To study the prevalence and genotype of human parvovirus B19 virus among blood products and plasma pools in China. Methods B19 DNA derived from 16 lots of factor Ⅷ concentrate produced by 4 manufactures and 10 lots of plasma pools were detected by nested PCR. Phylogenetic comparison of the partial B19 sequences obtained from positive samples were performed by direct sequencing. Results Twelve of sixteen lots of factor Ⅷ concentrate and all of ten lots of plasma pools were contaminated by B19 DNA. By comparing the partial B19 sequences,all the isolated viruses were genotype Ⅰ and their nucleotides were high conserved with homology of 98. 3%-100%. Conclusion B19 genotype Ⅰ DNA has been detected in high prevalence in factor Ⅷ concentrate and plasma pools. The genetic diversities were shown to be very low.
ABSTRACT
Air purification and disinfection are effective for the control of indoor air contaminationthe by microorganism and the improvement of indoor air quality. In this paper, the new progresses of the effectiveness of the methods for air purification and disinfection,including ventilation,ultrovialet disinfection,air filtration,chemical disinfection (ozone,formaldehyde,) are reviewed.