昭和24年～29年の6ヵ年間における京都府下の日本腦炎の研究

抄録

In the 6 years from 1949 to 1954, 381 case; were reported in Kyoto Prefecture with the clinical diagnosis of Japanese B encephalitis. They were classified into 4 grou saccording to complement fixation reaction, pathological findings, virus isolation and clinical symptoms. The present report includes the epidemiology and the results of laboratory examinations on 274 confirmed encephalitis cases, belonging to 3 of the above 4 groups.
1) The incidence rate of Japanese B encephalitis in Kyoto Prefecture was lowre but in exceptional years than the average of whole Japan.
2) The peak of incidence curve fell at the end of August. The year in which the first patirnt was reported early, brought a high total number of patients with a high case mortality rate.
3) The incidence in the male was higher than that in the female.
4) The age morbidity rate had its peaks at 5-9, 25-29 and over 55 in the male, and at 5-9 and over 50 in the female. In the latter an accumulation of incidence at 25-29 was not confirmed.
5) The age mortality rate was highest in the older ages over 45 in both sexes. On the whole, the mortality rate was higher in the female.
6) In 87% of total mortal cases the death occurred on five days from the 4th to the 8th day of disease. Patients over 50 years of age died earlier than those of other age groups.
7) In the city the regional morbidity rate was highest in such wards, which are situated along Higashiyama (eastern hill zone) and lowest in the central part. Outside the city, Amada Province had the highest incidence, which outnumbered that of every ward in the city. The lowest incidence was found in Soraku and Otokuni Provinces. It was below 1 in a year on an average.
8) The rate of positve complement fixation reaction with patients' serum was low at the early stage, but it already rose to 72% on the 8th day of disease. From the 12th day on the reaction turned to positive in almost all cases.
9) It was noticed that meningoencephalitis due to mumps virus was included in suspect cases of Japanese B encephalitis. Mumps virus was isolated from the cerebrospinal fluid in one of such cases.