Dengue, Japanese encephalitis and West Nile flaviviral infections detected during a dengue outbreak in Sonepat district, Haryana state, India.

During October 1997, three cases of encephalitis were admitted in Bara Hindu Rao Hospital, Delhi, from Murthal village in Sonepat district of Haryana state. In a follow-up study, out of the 30 serum samples collected, eight were found positive for dengue IgM antibodies. Two samples were positive for all the three infections, viz. dengue (DF), Japanese encephalitis (JE) and West Nile (WN) virus, while one sample was positive for two infections, viz. Japanese encephalitis and West Nile. Three male and 10 female cases showed past flavivirus infection. During the Aedes survey, house and container indices were estimated at 31.4% and 13.0% respectively. The Aedes aegypti landing rate was observed to be 36 per person per hour. The current episode was confirmed to be due to dengue infection. However, JE and WN virus infections were also present in the area.