National Research Centre on Equines, Sirsa Road, Hisar-125001, India.
Japanese encephalitis (JE) is a zoonotic mosquito-transmitted viral disease causing acute encephalopathy among humans and horses in the tropics. Regular outbreaks of JE are reported from human population in India, however, the prevalence of JE among equines in India is not known. A nation-wide equine sero-surveillance was initiated during 2006–07 to know the status of JE in India. Equine serum samples from seven different states were collected and tested for antibodies to JE by haemagglutination inhibition assay and results of HAI were confirmed by virus neutralization test (VNT). Antibodies to JE were detected in 117 of 875 (13.37%) equines tested in India during 2006–07. Maximum seroprevalence of JE was observed in equines of Manipur (91.67%), followed by Gujarat (18.45%), Chattisgarh (7.62%), Madhya Pradesh (7.24%), Rajasthan (6.67%), Haryana (4.97%) and Punjab (4.92%). The retrospective JE seroprevalence in Manipuri equines was also assessed by testing the archived serum samples of Manipuri equines collected during year 2005 by the centre. Out of 40 equine sera collected during year 2005, 14 (35%) were detected JE-positive. The findings of this study indicate that JE is prevalent in different states of India and it is highly endemic among equines in Manipur. The JE seropositivity in equines of Gujarat indicates the circulation of the virus in the state and possible threat to its animal and human population.
