Abstract
A survey was conducted in Tottori Prefecture over a period of May, 1966, to October, 1967, to clarify the seasonal prevalence of mosquitoes and the development of hemagglutination-inhibiting antibody against Japanese encephalitis in man and swine. The following results were obtained.
1) When examined by the light-trap collection of mosquitoes at 3 fixed points in Tottori City, Culex tritaeniorhynchus summovosus appeared in cattle barns in the middle of May, and in other points about three weks later.
The highest peak of prevalence was reached late in June. The activity of mosquitoes was continued until late in July. A declining trend in prevalence was shown early in October.
2) Cubex pipiens complex began to appear in the middle of April in cattle barns, and a decline of prevalence was shown early in August.
3) Anopheles hyrcanus complex began to appear in the middle of June at each point. Its seasonal prevalence was similar to that of Culex Summorosus.
4) Fifty per cent of the pigs surveyed gave positive hemagglutination-inhibition (HI) tests, or 1:20 or above, about four weeks after the appearance of Culex tritaeniorhynchus. 5) The first human case of Japanese encephalitis that was confirmed as such by the HI test was detected about two weeks after 50 per cent of the pigs surveyed had given positive HI tests.
