OBJECTIVE: To investigate the natural
infection and
genotype of Japanese
encephalitis virus in
mosquitoes and swine in some areas of Zhejiang province. METHODS: Samples of
mosquitoes and sera of swine were collected in three counties (Xianju, Longquan and Cixi) of Zhejiang province from May to October in 2007. 10 662
mosquitoes were collected during 2007, of which, C.pipiens pallens and C.quinquefasciatus were the most dominant species and 204 pig serum samples were detected. Japanese
encephalitis virus in
mosquitoes were detected by
virus isolation and real time
RT-PCR. The
antibody against Japanese
encephalitis virus in swine was detected by
ELISA. The isolated strain were identified by real time
RT-PCR. The PrM gene of the isolated strain was amplified by
RT-PCR. Three strains were typed by the gene of PrM. RESULTS: Seven positive
mosquitoe samples were identified by real time
RT-PCR. Three strains were isolated and identified by real time
RT-PCR. The PrM gene was
cloned and
sequenced. The
phylogenetic analysis showed that three isolates belong to
genotype I of Japanese
encephalitis virus. Of 204 swine serum samples, 121 positive samples were identified positives. Above 50% sera samples from swine were positive in June. CONCLUSION: The vector of Japanese
encephalitis virus existed and carried the Japanese
encephalitis virus in these areas of Zhejiang province. Three strains of Japanese
encephalitis virus were isolated from
mosquito pools collected in Zhejiang province. It should be the first isolation of
genotype I Japanese
encephalitis virus in Zhejiang province in recent years.
