STUDYING OF THE EXISTENCE OF JAPANESE ENCEPHALITIS (JE) IN NATURE

 

Phan Thi Nga

National Institute of Hygiene and Epidemiology, Ha Noi

 

Haemagglutination Inhibition test was applied to study sero-conversion in sentinel pigs in HoaiDuc-HaTay, 2002. The results showed the sero-conversion in pigs occurs all the year round. Vero and C6/36 cells were used to isolate JE virus from 83 mosquito pools and 30 pig blood samples that were collected in HoaiDuc-HaTay, 2002. From mosquito pools, 7 JE virus strains were isolated. From pig blood samples 4 JE viruses were isolated. These JE virus strains were isolated either in the epidemic or in the un-epidemic season. This study proves that JE virus is over wintering in mosquitoes. Genotype I, a new genotype has been found in Vietnam base on the results sequencing of E gene region JE virus strains that was isolated from mosquitoes and pigs in HoaiDuc, HaTay (North of Vietnam) in 2002.