流行性出血热(EHF)人群自然自动免疫动态研究

Studies on Natural active immunity of Epidemic Hemorrhagic Fever (EHF) in Population of Henan ProvinceⅡ. Dynamics of Natural active immunization of ENF in resident of three type epidemic areas

本研究对三种类型EHF疫区固定人群的抗体连续三年检测,以抗体累计阳性法统计分析,发现三种疫区人群均可通过自然感染获得动态的免疫屏障。家鼠型疫区流行过后人群抗体水平较高,但人群累计抗体流行率增长较慢;而有野鼠的疫区人群抗体水平虽较低,但因仍继续潜在流行1～2年,从而家、混、野三类疫区人群抗体流行率分别可达16.92％、18.43％和19.22％的相近水平。当人群抗体流行率达1～2万/10万(即10～20％)时,该病的流行即趋于减弱或停止,证明EHF可以形成一定的自然免疫屏障。只有这种屏障被易感人群的累积所冲破才有可能再次流行。并认为个体有1:20的EHFIgG抗体可防止再次感染,且抗体无论阴转与否3～5年间仍有免疫力。基此,亦为人群和个体人工免疫的可行性提供了有力证据。

This study discovered that the protective antibody in high level in the people of 3 kinds of epidemic areas could be accumulated naturally during EHF was epidemic.When the positive rate of EHF antibody in the crowd was 10000-20000/100000,the epidemic tends to reduce or stop.The result indicated that immunitive barrier in the crowd was already formed naturally.When the immunitive barrier (or balance) was broken due to the gradual reduction of the protective antibody of the crowd and the increase of the number of susceptible persons,the epidemic of EHF would occur again.When the positive rate of the crowds was 10000-20000/100000,the protectively immunitive barrier formed.The titer of effectively protective antibody examined with IFAT was 1:20.Reinfection was not found after 3-5 years in persons infected by EHFV,whatever the EHF antibody disappeared or not.