[Surveillance and control of Japanese encephalitis in Henan province, 1950 - 2008]

To analyze the characteristics and trend of Japanese encephalitis (JE) in Henan province.

Adopting descriptive epidemiological method to analyze the data on the epidemic situation of JE from 1950 to 2008, and on mosquitoes and host animals at disease surveillance points. The host serum JE IgG antibody was detected by ELISA. Data was analyzed using SPSS 12.0 and Excel 2003 software.

The incidence of JE in Henan province had a fluctuant downward trend. Peak of the incidence fell in July to September, accounting for 88.09% of total cases. The scope of geographical distribution was increasing from northern to southern parts of the province. Cases mainly concentrated in the southern and south-eastern parts of the province. 0 - 14 year-old group had the highest incidence (81.95%). In Luoyang city, there was a significant increase in children at 15-years or older (58.93%). Most patients were farmers (42.33%). The positive-times for half of the antibodies of JE in piglets of the surveillance sentinels were different, which might be the reason for the different levels for the incidence rates. The proportion of different kinds of mosquitoes were also different in surveillance sentinel sites, and the time for the density peak of the mosquitoes was in accordance with the incidence peak of JE.

To develop control strategies, evidence should be based on the characteristics of geographical variance, age, occupation differences, data related to monitoring on animal host and media mosquitoes of JE incidence in Henan province.