Serological evidence for Japanese encephalitis virus and West Nile virus infections in water frequenting and terrestrial wild birds in Kolar District, Karnataka State, India. A retrospective study.

In a serological survey of birds in a Japanese encephalitis (JE) endemic area of Kolar District, Karnataka State, India, 859 bird sera were tested by hemagglutination-inhibition test (HIT) for JE encephalitis and West Nile encephalitis (WNE) viruses. Only 2 (0.002%) and 178 (20.72%) sera were positive for JE virus (JEV) and WNE virus (WNV), respectively. Only 160 (18.63%) of 859 sera could be subjected to neutralizing test (NT). Of these, 20 (12.50%) and 62 (38.75%) were positive for JEV and WNV antibodies, respectively. These findings indicate that bird species such as Pond Herons and Little Egrets among ardeid birds and Grey Partridges and Quails among terrestrial birds are infected with JEV and WNV and play probably a role in the maintenance of these viruses in the abovementioned part of India.