Survey on the prevalence of Nipah virus in Pteropus medius bats from non-outbreak regions of India.

Recurrent Nipah virus (NiV) outbreaks have been reported in India from the states of Kerala and West Bengal. Pteropus medius bats, the reservoir hosts for NiV, are prevalent in the country and were found to harbour the virus in the outbreak-reported regions in the eastern and southern parts of India. Considering the scanty information available about the presence of the virus in bats from other regions of the country, we have conducted a cross-sectional survey in 8 states. The P. medius bats (n = 533) were sampled (throat, rectal and urogenital swabs, and blood) from 21 roosts across 8 states in India. The swab samples were tested for NiV RNA by real-time qRT-PCR and confirmed by sequencing. The serum samples were tested by bat anti-Nipah IgG ELISA. Although the NiV RNA positivity could be detected only from a single bat (sampled from Uttar Pradesh), anti-Nipah IgG seropositivity could be detected in bats sampled from 3 states (Goa, Maharashtra and Uttar Pradesh). The NiV genome retrieved showed close homology to sequences previously reported from Kerala state, India. Pteropus medius bats sampled from non-outbreak regions of India demonstrated the presence of NiV, urging us to strengthen the NiV disease surveillance across the country.