Japanese encephalitis virus infection in cattle: comparison of antibody distribution in the central and southern regions of Japan

일본중부(日本中部)와 남부(南部)의 우(牛)에서 일본뇌염감염(日本腦炎感染)에 관한 역학적(疫學的) 연구(硏究)

The frequency of appearance of HI antibody against Japanese encephalitis virus was investigated over the three-year period 1982 through 1984. The sample population consisted of 1306 cattle in Saitama prefecture (located in central Japan), and 536 cattle in Kagoshima prefecture (located in southern Japan). During the study period, there was no significant difference in the average antibody-positive rate between cattle in Kagoshima (68.8%) and those in Saitama (65.5%). Variations in the monthly antibody-positive rate and mean monthly antibody titer in the Saitama cattle followed a mountain-like pattern with the peak observed during summer. In the Kagoshima cattle, both parameters also increased in summer and these increases persisted even in winter. The distribution of antibody-positive rate as a function of age ranged from 64.0% to 82.8% in Saitama, though no correlation was observed between these two factors. In the Kagoshima cattle, however, the antibody-positive rate increased with age as follows; the values averaged 29.4% in the one-year-old cattle group, 50.0% in the two-year-old group, 47.4% in the three-year-old group and 74.5% in the four-year-old group. There was no significant correlation between the mean antibody titer and age in either Saitama cattle (15.3~22.5) or Kagoshima cattle (20.0~32.3).

1982년(年)부터 1984년도(年度)까지 3년간(年間)에 걸처, 일본내(日本內) 중부(中部) Saitama현(縣)의 우(牛) 1,306두(頭)와 남부(南部)의 Kagoshima현(縣)의 우(牛) 536두(頭)를 대상(對象)으로 하여 일본뇌염(日本腦炎)바이라스 (JEV)의 적혈구응집억제(赤血球凝集抑制) (HI) 항체양성율(抗體陽性率)을 검사(檢査)한 바, Kagoshima현(縣)에선 68.8% 그리고 Saitama 현(縣)에서는 65.5%가 양성(陽性)이었다. 계절별(季節別)로는 양지역(兩地域)이 공(供)히 하절(夏節)에 항체양성율(抗體陽性率)이 높았고, 연령별(年齡別) 양성율(陽性率)은 Saitama 현(縣)의 경우 64.0%부터 82.8%까지 분포(分布)하고, Kagoshima현(縣)의 우(牛)는 1세군(歲群)에서 29.4%, 2세군(歲群)에선 50.0%, 3세군(歲群)에선 47.4% 그리고 4세군(歲群)에선 74.5%의 양성율(陽性率)을 나타내었다. 그리고 양지역(兩地域)의 연령(年齡)과 항체력가간(抗體力價間)에는 상관성(相關性)이 없었고, Saitama현(縣) 우(牛)의 역가(力價)는 연령(年齡)에 따라 15.3~22.5, Kagoshima 현우(縣牛)은 20.0~32.3이었다.