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Page No. : 45-48

ABSTRACT

Japanese encephalitis virus (JEV) is a significant zoonotic cause of encephalitis in Southeast Asia. Pigs play a central role in the transmission and spillover of JEV. Tamil Nadu, a state in southern India, lacks epidemiological study on JEV in the context of spillover risks associated with different landscapes. This study aims to assess the prevalence of JEV in pigs across three landscapes such as coastal wetlands, river delta and central semi-arid plain in Tamil Nadu, with a focus on estimating landscape-based spillover risks to humans. A cross-sectional study sampling 327 pigs reared in different landscapes was conducted from May 2022 to May 2023. Serum samples were tested for JEV antibodies using in-house recombinant NS1-based IgM and IgG ELISA. Data on human spillovers were extracted from the national portal of the Integrated Disease Surveillance Program. Spillover risk was estimated through deterministic mathematical equations. The apparent seroprevalence of JEV was 60.85% (95% CI: 42.5% – 79.6%). Among the different landscapes, coastal wetlands exhibited a seroprevalence of 60.4% (95% CI: 53.1% – 66.4%) delta had 76.4% (95% CI: 50.1% – 93.2%), and semi-arid plain 48.9% (95% CI: 38.9% – 50.2%). While the corresponding landscape risk factor is estimated as 50.81%, 43.7%, and 0%, and spillover risk is 0.004386, 0.0033 and 0.0016 respectively. The study identifies that the JEV spillover risk is more in coastal wetlands followed by river delta while the risk is very minimal in central semi-arid plains. A One Health approach, involving collaboration between animal and public health authorities, is essential for controlling JE in this region.

Key words: Japanese encephalitis, Pig, Tamil Nadu, Landscapes, Spillover risk