著者

緒方 正名 長谷川 敬彦 高越 良明 竹久 亨 長尾 逸子 寺谷 巌 大隈 義文 人見 硬 長尾 寛 粟屋 研吾 高橋 武夫

出版者

岡山医学会

雑誌

岡山医学会雑誌 (ISSN:00301558)

巻号頁・発行日

vol.78, no.1supplement, pp.1-29, 1966-01-30 (Released:2009-08-24)

参考文献数

7

被引用文献数

1

---

1) Data has been presented on the trend of Japanese B. Encephalitis from 1959 to 1965 in Okayama, Miyazaki, Kagawa, Tokushima, Kochi, Ehime, Hyogo and Aichi Prefectures, middle and western parts in Japan.2) The prevalence started from Miyazaki, most southern part in Japan, and progressed succesively to Kochi, Okayama, Tottori and Miyagi. The difference in date between Okayama and Miyazaki was 20 days, Okayama and Kochi was 10 days, Okayama and Tottori, adjacent to northern part in Okayama, was 2 days and also the difference in date between northern and southern part in Okayama was 7 days. We woulld like to call this phenomenon “Tendency towards northeast”.This tendency can be arranged in the order of its average atmospheric temperatures. However, there is no correlation between the date of incidence in each year and the temperature gradient.3) From 1950 to 1959, the incidence rate was higher in the southern district than in the northern district, and from 1960 to 1965 it became higher in the northern district than in the southern district of Okayama Prefecture.4) The incidence rate by age from 1960 to 1965 was higher in the old over 60 ages in northern district and in the child below 10 ages in the southern district of Okayama Prefectuve. A marked tendency to decrease the incidence rate in the child has been seen since 1959. This downward tendency would be caused by the J. B. E vaccination.5) There is some indication from the geographycal distribution that the prevalence spreaded from focus to other villages contiguously, except for the town.6) In past five years the district where the incidence rate exceeded over 10/100, 000 peoples three times or exceeded over 20 was shown by the following districts, Northern district in Okayama. PrefectureEastern and western district in Tottori. PrefectureNorthwest district in Hyogo. PrefectureEast and west parts in Kochi. PrefectureSouthern district in Miyagi. PrefectureIn general, the high incidence was observed in the plain near mountain or the basin but not in the town.7) There is a phenomenon that when the incidence rate was over 20 in the year, the incidence rate next year became low.