江滩型疫区人群日本血吸虫再感染的前瞻性研究

PROSPECTIVE COHORT STUDY ON HUMAN REINFECTION WITH SCHISTOSOMA 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 12 9例感染者中 ,经吡喹酮治疗后虫卵转为阴性的 12 6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 L ogistic回归分析。结果 日本血吸虫病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 .5 5 6。控制这些因素可减少血吸虫再感染。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。

Objectives [WT5”BZ]To study human reinfection with [WT5”BX]Schistosoma japonicum [WT5”BZ]and its risk factors after chemotherapy in a middle endemic village of river beach region. [WT5”HZ]Methods [WT5”BZ]A total of 126 individuals in a river beach endemic area in Dangtu County, Anhui Province, who were rendered [WT5”BX]Schistosoma japonicum [WT5”BZ]egg-negative by praziquantel treatment, were taken as reinfection study population. Stool examination for identification of reinfection and investigation of factors related to reinfection were performed in the whole transmission season. All data were analyzed with unconditional logistic regression analysis. [WT5”HZ]Results [WT5”BZ]One year after treatment, the prevalence of reinfection in the middle endemic village was 13 49%, returning to the initial prevalence. Single and multiple factor(s) unconditional logistic regression analysis showed that 4 factors were associated with reinfection, i.e. the cercariae density in water, age, index of contacting contagious water from June to September, and the distance between residence and infected [WT5”BX]Oncomelania [WT5”BZ]snail spot, with relative risk (RR) being 10 396, 0 194, 3 413 and 2 556 respectively. Controlling these factors may reduce the reinfection rate. [WT5”HZ]Conclusion [WT5”BZ]These findings may form a basis for improving human ability against schistosome reinfection and taking suitable strategy to prevent human reinfection with [WT5”BX]Schistosoma japonicum [WT5”BZ]in these reigions. [WT5”HZ]