Investigation Of The Prevalence Of Japanese Encephalitis B In Zaozhuang Prefecture, Shandong

Objective:To provide the effective evidences for Japanese Encephalitis (JE) prevention by exploring the composition of JE vectors, JE virus (JEV) infection rate in mosquito and the level of JEV antibody from sera of local healthy resident. Methods:mosquito species survey methods, mosquito collection was used by lamp traps in the pigsty of surveillance site overnight, then indentifying and recording mosquito in the next morning; identified mosquito was separately stored in liquid nitrogen with freeze-stored tube as mosquito species; in laboratory, RT-PCR was used to isolate and identify JEV; the level of JEV antibody from sera of healthy resident around the surveillance sites, of those two- group ages between 1.5-20 years old and higher than 20 years old were collected(2ml/person) respectively, making their bloods into sera by centrifugation, and detecting their IgG antibody by ELISA kit. Results:A total of 33395 individual mosquitoes from 7 species in 4 genera were collected. Of these Culex tritaeniorhynchus was the local dominant species accounted for 92.84% (31730/34174) of the total collected mosquitoes. RT-PCR was used to isolate and identify Flavivirus, the positive rate is 38.1%; 6 JEV strains were isolated from Cx. tritaeniorhynchus and its rate of infected virus was 0.0175%, by their sequencing and identifying, these JEV belonged to the JEV genotypeâ… . The positive rate of JEV antibodies was 41.4%(116/278) of total 278 sera collected from the healthy residents, of 2-groups ages the JEV IgG positive rate in higher than 20 years group was higher than that in 1.5-20years group (x2=11.786, P<0.75), those in women were higher than men (x2=6.641, P<0.05) and those from unvaccinated group were higher than vaccinated group' (x2=13.215, P<0.05).Conclusions It's the first time to isolate JEV genotype I from Zaozhuang; Culex tritaeniorhynchus was the local dominant species and JE prevalence was serious; above results suggested that local department of disease prevention and control should be strengthened JE Vaccination inoculation and mosquito control.