Serological evidence for Japanese encephalitis and West Nile viruses in domestic animals of Nepal.

A regional survey was conducted in Nepal for antibody to Japanese encephalitis virus (JEV) in domestic animals. Sera from pigs, and limited numbers of ducks and horses were collected from 16 districts in 2002-2003 and subjected to three serological tests. Of 270 porcine sera tested by C-ELISA, 55% were found positive for the presence of antibodies against Japanese encephalitis virus. Additional testing for IgM antibody to JEV revealed less than 2% of C-ELISA positive sera had evidence of recent JEV infection. Plaque reduction neutralisation tests (PRNT) using JEV, Murray Valley encephalitis (MVEV) and Kunjin (KUNV) viruses implicated JEV as the flavivirus associated with the observed antibody response in most sero-positive pigs. However, eight porcine sera with predominant neutralising antibody for KUNV (an Australasian subtype of West Nile Virus) provided evidence for the circulation of West Nile virus in Nepal.