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Objective To determine the hosts of hantavirus (HV) and its molecular epidemiological characteristics, to provide evidence for prevention and control on hemorrhagic fever with renal syndrome (HFRS). Methods Rodents were captured by a special trap within the residential area. The antigens of HV in lung tissues were detected by direct immuno-fluorescence assay (DFA). Nucleotide sequences of HV were amplified by RT-PCR with HV genotype-specific primer. The amplified genes were then sequenced. Phylogenetic tree were built on nucleotide sequence with Clusta1X 1.83 software. Results 1421 rodents were captured and classified into 8 species of 4 Genera in the epidemic area within 10 counties of Chuxiong prefecture, Yunnan province, between 2005 and 2006. Out of the 1421 rodents, 1056 (74.31%) of them were Rattus norvegicas and 280 (19.70%) belonged to Rattus flavipectus. The antigens of HV were detected by DFA in lung tissues and the total positive rate of HV was 5.15% (53/ 1029). After applying the sequencing nucleotide method to the 53 positive specimens, data showed that 21 specimens were positive and all of them belonged to Seoul type ( 15 samples were from Rattus norvegicus, 4 samples Rattasflavipectas, 2 samples Rattus nitidas). The partial S segments from 12 specimens were sequenced which appeared homologic with R22, L99 and HLD65 from GenBank in relatively high level (87.1%-99.7%). When compared to 76-118 strain of Hantaan type, their homologic degree was only 64.4%-69.1%. Results from Phylogenetic analysis showed that 12 specimens belonged to Seoul type. As for their homology, they were significantly similar to Seoul type and could be tentatively divided into two subtypes S1 and S3. Conclusion It was confirmed that the Seoul type virus, as HFRS' s pathogenetic agent mainly carried by rats, prevailed widely in Chuxiong prefecture. Owing to the local ecological environment, we also noticed the characteristics of different HV subtypes among Seoul type.
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Objective To understand the epidemiological features of two rabies cases in Baoshan city year 2006 and 2007 and to analyze its source of infection.Methods Questionnaires were used to do the epidemiologieal survey on each of the rabies cases.Brain timue samples of rabies patients were collet to detect the rabies virus by direct immunofluoreseence assay(DFA)and RT-PCR assay.Homology and phylogenetic tree were analyzed.based on the whole nucleotide and deduced amino acid sequence of P,M and N gene of rabies virus followed by molecular epidemiological analysis.Results In July 2006,one human rabies case was identified in Longyang district,and another one in Tengchong county in Baoshan city in 2007.The degrees of exposure of these two patients was all at degreeⅢ.Two brain tissue samples among the dead patients(No.CYN0601H and CYN0701H)were confirmed positive by both DFA and RTPCR assay.The homology analysis of P,M and N gene sequences among CYN0601H,CYN0701H and other rabias strains isolated from other provinces and other counties.showed that the samples in Baoshan city shared the highest homology with the strains in Thailand.Phylogenetic analysis indicated that the two samples were very dose and all belonged to genetype 1 Lyssavirus,with the closest relationship between samples in Baoshan city and strains in Thailand.Conclusion It Was confirmed on the virus molecular level that the two patients in Baoshan city were both suffered from rabies.The prevalent strains in Baoshan city WaS probably imported from foreign country,suggesting that prevention and control measures on rabies virus in the boarder areas of Yunnan should be strengthened.
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In July 1997, a strain (GB30) of virus was isolated from 60 samples of brain tissues of Murina aurata (Chiroptera: Vespertilionidae) co llec ted in Gengma county, Yunnan province, China. Isolation of virus was negative fr om 4 samples of brain tissues of Rousettus leschenaulti (Chiroptera: Pteropo did ae) collected in Gengma. GB30 virus strain could regularly cause illness and dea th in suckling mice, produced evident CPE in BHK21 cells. It agglutinated red b lood cells of dove at pH5.75～7.4. This virus has been identified serologically by hemagglutination inhibition and immunofluorescent tests using Japanese enceph alitis (JE), dengue (DEN) type 1,2,3,4, and chikungunya (CHIK) viruses monoclona l antibodies, and JE and sindbis (SIN) viruses immune sera. It showed specific r eaction to JE virus only and no reaction with DEN 1～4, CHIK and SIN viruses. Th erefore it can be identified as JE virus. This is the first report on the isolat ion of JE virus from Murina aurata. The results showed that bats are conside red as the reservoir and amplifier host of JE virus transmission in nature.