1145 cases of Japanese encephalitis have been reported from 14 districts of  Uttar Pradesh Province , India from 29 July to 30 August 2005. About one-fourth of these (n=296) have died. 90 cases from the adjoining districts of Bihar have also been admitted to the hospitals in Uttar Pradesh. Majority of the affected villages have reported only single cases. Entomological surveys in the affected villages have revealed high density of Culex tritaeniorhynchus and Culex vishnui group – the vectors of JE.

Almost all cases are below 15 years of age. They usually presented with acute onset of fever with encephalitis followed by delirium and death within a short period. Cases who have survived show evidence of mental retardation and/or neurological deficit. Of 168 serum/CSF samples examined, 92 (55%) were found positive for IgM antibodies against JE.

Control measures taken include (i) a massive health education campaign to increase awareness about the importance of early treatment of cases, how the disease spreads and what measures can be taken by the community to reduce the risk of infection, (ii) circulation of standard case management guidelines to the hospitals for better patient care to reduce the mortality, (iii) malathion fogging and pyrethrum spray in the priority villages. About 300,000 doses of JE vaccine manufactured at Central Research Institute, Kasauli, India have been sent to the State Government. Public health experts and senior pediatricians are already in the affected area to assist the local health authorities in outbreak investigations and instituting control measures.  The situation is being continuously monitored at the highest level.

WHO does not recommends any travel or trade restrictions.