Study of the outbreak of Japanese encephalitis in Lakhimpur district of Assam in 1989.

An outbreak of Japanese encephalitis was reported from Lakhimpur district of Assam in July-August, 1989. The outbreak affected 90 villages of the district, covering a population of approximately 36,000. There were 140 cases and 70 deaths due to the epidemic, giving a case fatality rate of 50%. There were no cases from Gogamukh area of the district, where a pilot Japanese encephalitis vaccination project was conducted in the population between July-August 1987, with Kasauli Japanese encephalitis vaccine. Serological examination of acute and convalescent cases showed Japanese encephalitis specific IgM indicating strong evidence of recent Japanese encephalitis infection.