Getah virus infection of Indian horses

An outbreak of disease, characterized by depression, anorexia, fever, limb oedema and lymphocytopenia, occurred on a farm for thoroughbreds in India in 1990. Twenty-six of the 88 horses on the farm were affected, predominantly adults. Signs were present in affected horses for 7-10 days, and the outbreak lasted 21 days. Seven of the 26 affected horses were tested for exposure to Getah virus using paired serum samples, acute and convalescent. Four of the 7 horses seroconverted to Getah virus, and the other three showed a 4-fold or greater rise in titre. The clinical and laboratory findings were similar, but not indentical, to those described in natural and experimental infections in Japanese horses. This is the first description of disease caused by Getah virus infection in horses outside Japan. In addition serum samples from 152 horses from 3 regions of India were evaluated for the presence of antibodies to Getah virus. The seroprevalence was found to be 17%, indicating exposure to the virus elsewhere in Indian horses.