Low rate of Japanese encephalitis infection in rural children in Thanjavur district (Tamil Nadu), an area with extensive paddy cultivation.

In Thanjavur district, the occurrence of Japanese encephalitis (JE) is very low and the district is free of epidemics. Among children aged 5-12 yr, the infection rates for JE in two consecutive transmission seasons of 1991-92 and 1992-93, were 1.8 and 5.1 per cent respectively. A high cattle to pigs ratio (400:1) could possibly be an important factor for the low JE infection rate in children in the district.