A serological survey of arboviral diseases among the human population of the Andaman and Nicobar Islands, India.

In an attempt to determine the prevalence of certain arthropod-borne viruses of public health importance amongst the human population of the Andaman and Nicobar Islands of India, 2,401 sera were collected from six major localities. The sera were analysed by the hemagglu- tination inhibition (HI) and neutralization (N) tests, using Chikungunya (CHIK), Japanese en- cephalitis (JE), West Nile (WN), dengue (DEN-2), Langat (TP-21) and Kyasanur Forest disease (KFD) viral antigens. The highest prevalence of HI antibodies was detected against KFD virus (22.4%), followed by Langat (20.2%), JE (5.9%), DEN-2 (3.1%), CHIK (2.9%) and WN (0.8%) viruses. Cross-reactions to the viral antigens were also noted. The results of N tests indicated a high prevalence of DEN-2 (25.4%) virus, followed by Langat (17.5%), CHIK (15.3%), KFD (12%), JE (2.1%) and WN (1.8%). These results are discussed in relation to important epide- miological parameters like age, sex and geographical location. To our knowledge, this is the first report of an extensive serosurvey of arthropod-borne viruses on these islands.