Survey on antibody to Getah virus in horses in Japan

A seroepidemiological survey was performed on antibody against Getah virus in horses in Japan by the complement fixation test. The positive rate was 35 and 53% in two areas where an outbreak of the infectious disease was reported, whereas it was in a range of 3.3 to 24.2% in other areas, except in certain prefectures of the Kyushu district where a high positive rate was observed. In the Hokkaido district, the northernmost part of Japan, no reactors were found in horses under 6 years old, unlike in any other district. It was also suggested that Getah virus infection might have already been prevalent among horses in Japan before the outbreak of the disease in 1978. It remained to be elucidated, however, that the antibody detected might have been produced by some virus which was antigenically related to Getah virus.