新安县乙型脑炎流行病学分析

对新安县流行性乙型脑炎（简称乙脑）发病情况的监测结果表明：新安县的主要蚊种为骚扰阿蚊、淡色库蚊和三带喙库蚊。淡色库蚊的密度高峰与乙脑发病高峰相一致，约比乙脑发病高峰早３～４周，并从淡色库蚊中分离到１株乙脑病毒，其最低现场感染率为１：３００，自然带毒率为３．４８‰±０．００３４７。初步证实了淡色库蚊为当地乙脑流行的主要传播媒介之一。骚扰阿蚊不具备成为当地乙脑主要传播媒介的可能性。在乙脑流行年，大多数的猪受到乙脑病毒的感染，猪的５０％阳转日约比人间发病高峰早３周。各年龄组人群普遍受到感染，人群乙脑抗体阳性率较流行前有明显增高。人群的隐性感染率为２８．８５％，同时有４．８％的人体内抗体下降或转阴。显隐感染之比为１：１９４５。大年龄组人群发病数有所增加，但从年龄别发病率来看，仍以１０岁以下年龄组儿童的发病率较高。提示乙脑的预防重点仍应以此年龄段儿童为主。

THE EPIDEMIOLOGICAL STUDY OF JAPANHESE B ENCEPHALITIS IN XINAN COUNTY

The influencial factors of Japaneses B encephalitis (JE)in Xinan county wasinvestigated.The result showed the main kinds of mosquito in Xinan county were Armigeresobturgbans,C.pipiens and C.tritaeniorhynchus.C.pipiens was one of the main spread medi-ums of JE. Arn1igeres was not the major spread medium of JE. The inapparent infection rateof crowd was 28. 85%.The antihody of 4.8 percent of crowd reduced or disappeared.Thecases of the older people increased than the other county,but the incidence rate of the youngpeople(<10 years)was significantly higher than that of the older people (>10 years)(U=48.93.P<0.O1)