[Japanese encephalitis virus infection in cattle: a serological survey in Saitama and Kagoshima Prefectures].

Serum samples were collected from a total of 1,306 and 536 cattle raised in Saitama and Kagoshima Prefectures, respectively, during a period from 1982 to 1984. Their antibody titers against Japanese encephalitis virus (JEV) were determined by the hemagglutination-inhibition test. Antibody prevalences were 65.5% (856/1306) and 68.8% (369/536) in Saitama and Kagoshima Prefectures, respectively. In both prefectures, there was a rapid increase in positive rate and mean titer in summer. Afterwards, there was a gradual decrease in both rate and titer in Saitama Prefecture in winter. In Kagoshima Prefecture, however, the rate and titer did not so markedly decrease in winter, but remained high in December. The rate of positive reactors to JEV in Kagoshima Prefecture increased gradually from 29.4% (1 year old) to 74.5% (4 years old) with advance in age. This rate in each age group remained almost at the same level ranging from 64.0% to 82.8% in Saitama Prefecture.