流行性乙型脑炎(以下简称乙脑)是威胁我省人民健康的一种主要急性传染病。建国前,未见河南有资料报告:建国后,从1950年开始有病例发生,并在此之后的三十九年中,疫区不断扩大,目前全省各县(市)均有病例报告,是全国主要发病省份之一。1970年,全年发病总人数曾高达32460人[1-3]。根据疫情报告:河南省从1950年到 Japanese encephalitis (hereinafter referred to as JE) is a major acute infectious disease that threatens the health of our people. Before the founding of New China, there was no reported data in Henan Province. Since the founding of the People’s Republic of China, cases have been reported since 1950, and in the 39 years since then, the epidemic area has been continuously expanded. At present, there are case reports in all counties (cities) It is one of the major disease provinces in China. In 1970, the total number of incidences in the whole year was as high as 32,460 [1-3]. According to the epidemic report: Henan Province from 1950 to