節足動物媒介ウイルスの生態学的研究
第 5 報 蚊と日本脳炎
1968 年 18 巻 5 号 p. 494-500
詳細
1968 年 18 巻 5 号 p. 494-500
Mosquito factors concerning the human epidemics of Japanese encephalitis (JE) were strongly suggested from the data of the field trials during 1959 to 1965. In these research programs, mosquitoes were collected at study sites every year from May to October and tested for JE virus, and specimens from the patients clinically diagnosed as encephalitis and other related illness were examined throughout the year for etiological agent.
The results are as followsi
1) 12 species of mosquitoes were collected in study sites. However, JE virus was isolated from only C. tritaeniorhynchus and C. pipiens, and from none of other spebies. Abuot 99% of isolates were obtained from C. tritaeniorhynchus and it was the most commonly infected mosquito in this area.
2) By serologic and virologic examinations, no JE patient was found except in the summer season when the mosquito infections were observed.
3) Mosquito infection in this area was regularly limitted to the period from July to September, and the first human cases occurred about 2 weeks after the first isolate was obtained from mosquitoes.
4) In the years of major outbreaks, infected mosquitoes were found earlier than in normal years and high isolation efficiency (ratio of infected to total C. tritaeniorhynchus populations) was also observed.
