1 September 2005

Japanese Encephalitis in India

Cases of Japanese encephalitis (JE) have been reported from 14 districts of the northern Indian state of Uttar Pradesh.[1]

Most cases have occurred in young children and locals living in rural communities. Japanese encephalitis has been laboratory confirmed in a proportion of these cases.

Control measures have been initiated by local authorities and the situation is being monitored.

JE is transmitted by the bite of the Culex mosquito and is endemic in many parts of India.  Thousands of cases are reported each year. [2] Peak transmission season (May to October) in Northern India occurs during and just after the monsoon season when major outbreaks coincide with heavy rains and flooding. Case numbers in the region are reported to be higher this year than in previous years.

The risk of JE for travellers who stay for short periods in urban areas is low.  All travellers to endemic areas should be advised to practice insect bite avoidance methods, particularly between dusk and dawn, when the Culex mosquito vector is most active.

Vaccination is not usually recommended for short visits to urban areas.  Vaccine should be considered for those intending to stay for long periods in rural endemic regions during the main transmission season, those whose planned activities will increase their risk, and all long-term expatriates. 

References

1. World Health Organization Regional Office of South East Asia. Japanese encephalitis in Uttar Pradesh. www.searo.who.int/en/section10/section392_10243.htm

2.  Kabilan L, Rajendran R, Arunachalam N, Ramesh S, Srinivasan S, Philip Samuel P, Dash AP. Japanese encephalitis in India: An overview. Indian J Pediatr 2004;71:609-615Available at: http://www.ijppediatricsindia.org/article.asp?issn=0019-5456;year=2004;volume=71;issue=7;spage=609;epage=615;

aulast=Kabilan

Links

NaTHNaC Japanese Encephalitis information sheet http://www.NaTHNaC.org/pro/factsheets/japanese_enc.htm

US Centers for Disease Control and Prevention

http://www2.ncid.cdc.gov/travel/yb/utils/ybGet.asp?section=

dis&obj=jenceph.htm&cssNav=browseoyb