广东省班氏丝虫病防治后期人群和媒介感染情况观察

目的 探索人群微丝蚴率降至1％以下，终止防治措施后人群和媒介感染情况。方法 终止防治措施后，1988～2000年在原广东省班氏丝虫病流行区抽查30％以上流行镇，重点村居民夜间采血120μl血检微丝蚴，在血检点捕集致倦库蚊解剖，观察自然感染情况；选定10个县原丝虫病流行较严重的村，纵向观察人群和媒介感染情况。结果 1988年人群微丝蚴率为0．33％(575／172631)，此后人群微丝蚴率和致倦库蚊自然感染率逐年下降，1997年后无微丝蚴血症者；1992．2000年共解剖致倦库蚊248115只，无发现自然感染幼丝虫；1988～1995年纵向观察，1988年人群微丝蚴率和蚊自然感染率分别为0．14％和0.07％，1994年后两者均为0。结论 班氏丝虫病经防治后，人群微丝蚴率降至1％以下则可阻断传播，10年后人群微丝蚴血症消失。

Microfilarial infection in human and vector in the late stage of bancroftian filariasis control

Objective To explore the filarial infection rate in human and vector after the filariasis control stopped in which the microfilarial rate less than 1%. Methods Blood sample in residents and Culex quinquefasciatus were collected to examine the natural filarial infection rate in 30% epidemic townships in 1988-2000. Longitudinal observation in both human population and vector was carried to test the infection level in ten severe epidemic counties. Results Microfilarial rate in human dropped from 0.33% in 1988 to 0% since 1997 and the rate in vector has dropped to 0% since 1994. Conclusion The bancroftian filariasis transmission can be interrupted when the microfilarial rate in human population has dropped to less than 1% and the microfilarial rate can reach zero after 10 years.