A close correlation was observed between 3 climatic factors (atmospheric temperature, duration of sunshine and rainfall amounts in July) and the date showing 50% positive rate of hemagglutination inhibition (HI) antibody of Japanese Encephalitis in swine in each prefecture of Japan from 1982 to 1988.
The multiple regression equation to estimate the date showing a 50% positive rate of HI antibody in swine from 3 climatic factors was established.
A close correlation was obtained between the date showing 50% positive rate of HI antibody in swine and the date showing first outbreak of Japanese encephalitis patient, and the difference in days from the latter to the former was calculated to be 20.6±11.5 days.
