江滩型疫区人群日本血吸虫再感染的前瞻性研究

A PROSPECTIVE COHORT STUDY ON HUMAN REINFECTION WITH SCHISTISOMA JAPONICUM IN RIVER BEACH ENDEMIC AREAS

目的研究江滩型日本血吸虫病中度流行区化疗后人群再感染及其危险因素。方法选择安徽省当涂县一江滩型血吸虫病流行村作为观察试区。追踪观察129例感染者中吡喹酮治疗后虫卵转为阴性的126人在一个感染季节内的再感染情况。同时调查当地螺情和水体感染性变化情况以及居民接触疫水情况等因素;再对其进行单因素和多因素非条件 Logistic 回归分析。结果基线感染率为13.37%的江滩型日本血吸虫病中度流行区患者化疗后,经过一个感染季节其再感染率高达13.49%.基本恢复到化疗前人群感染水平。接触疫水处水体尾蚴密度、年龄、6～9月疫水接触指数、居住地距阳性螺点距离是再感染发生的主要危险因素,其危险度分别为10.396、0.194、3.413、和2.556。结论本研究为提高人群抗再感染的能力和制订预防血吸虫再感染的措施提供了理论依据。

Aim To study reinfection with Schistisoma japonicum after chemotherapy in a meddle endemic village of river beach region and its risk factors.Method A total of 126 individuals in a river beach endemic areas in Dangtu counth,Anhui Province,who were rendered Schistisoma japonicum egg-negative by prazquantel treatment, were taken as reinfection study population.Stool examination for identification of reinfection and investigation of factors related with reinfection were performed in and over the whole transmission season.All the resuots were analyzed with unconditional logistic regression analysis.Result One year after treatment,the prevalence of rein- fection in the meddle endemic villagn was 13.49%.returning to the initial prevalence.Single and multiple factor unconditional logistic regression analysis showed that 4 factors were associated with reinfection,i.e.the cercari- ae density in water,age,index of contacting contagious water from June to September,and the distance be- tween residence and infected oncomelania snail spot,with relative risk(RR)being 10.396,0.194,2.56 and 3.413 respectively.Controlling these factors will reduce the reinfection rate.Conclusion these findings may form a basis for improving human ability to antischistosome reinfection and taking suitable strategy to prevent human reinfection with Schistisoma japonicum in these regions.