汛期长江江滩与支流河滩的水体血吸虫感染性时间分布规律

摘要

目的 研究汛期长江江滩及其支流河滩的水体血吸虫感染性规律,为急性血吸虫病防控策略和措施的优化提供依据.方法 在长江安徽段选择2009年春季查获感染性钉螺的长江江滩和支流河滩各一块,于当年6～10月份采用哨鼠法每月1次连续测定水体感染性.结果 汛期6～10月份的长江及其支流滩地水体均具有血吸虫感染性,感染强度与滩地春季感染性钉螺密度密切相关.江滩水体感染强度以6月份最高,哨鼠感染率、平均虫负荷(成虫条数/鼠)分别为92.9％、11.3,其次为8月(76.7％、11.4),10月份最低(26.7％、1.4).河滩水体感染强度以9月份最高,哨鼠感染率、平均虫负荷分别达66.7％、14.8,6月份次之(51.7％、5.0),10月份亦最低(10％、0.4).结论 汛期长江江滩和支流河滩水体血吸虫感染性均呈涨水期(6月)和高水位期(8～9月)的双峰型特点,汛前加强主要传染源粪便管理及查灭螺力度是急性血吸虫感染防控的关键.%Objective To study the temporal distribution of water infectivity of schistosome at the beaches along the Yangtzer River and its branch in flood season, which aim to provide some evidence for the optimization of acute schistosomiasis control strategies. Methods Two pieces of marshland infested with infective snails in spring of 2009, along the Yangtze River and its branch in Anhui province was selected as observation spots. The sentry mice test was use to detect water body infectivity of schistosome once a moth from June to October. Results Both the beaches of the Yangtze River and its branch had continuous infectivity of schistosome from June to October. For the marshland of the Yangtze River, the highest risk of Schistosoma Japon-icum infection occurred in the early flood season (June), in which the infection rate of sentry mice was 92.9%, with an average worm load of 13.1 (worms /mouse); that of August (76.7%, 11.4) rank the second; the intensity of water body infectivity descended to the lowest level in October (26.7%, 1.4). For the marshland of branch river, the highest infectivity of water body appeared in September when the sentry mice had infection rate of 66.7% with an average worm load of 14.8, that of June is the next (51.7%, 5.0), and the infectivity in October declined to the lowest level (10%, 0.4). Conclusion The water body infectivity of both the Yangtze River and its branch takes on the bimodal temporal distribution. Namely, the peak of infectivity of schistosome lies in the early flood season (June) and the period of higher water level (August or September). The crucial measures for prevention and control of acute schistosomiasis are to strengthen the management of feces dejected from main infection sources and snails eradication.