深圳市广州管圆线虫疫源地调查及流行特征分析

目的 了解深圳市散发的广州管圆线虫病患者和疫源地分布,及其主要传播途径和流行特征.方法 在深圳市12个不同生态环境地点调查广州管圆线虫不同宿主分布和感染情况,采用匀浆沉淀镜检法对各调查点捕获的中间宿主进行解剖,以确定中间宿主的感染率和感染度.用鼠笼捕获鼠类,解剖鼠体,在鼠心脏和肺动脉血管寻找广州管圆线虫成虫,从野生螺体内分离的广州管圆线虫幼虫进行实验室广州管圆线虫生活史的循环,完成实验室生活史的循环证实现场调查的结论.结果 在12个调查点中有4个区域发现褐云玛瑙螺阳性,分布在深圳市西南部,感染率平均为31%,螺的感染度与其体重相关,螺体重≥55 g的个体平均感染度显著性高于＜55 g的个体(P＜0.05);阳性螺区域终末宿主褐家鼠和黄胸鼠均有感染,感染率平均为12%,雌鼠的感染率显著高于雄鼠(P＜0.01).结论 深圳市存在广州管圆线虫自然疫源地,疫源地内广州管圆线虫在中间宿主和终末宿主之间广泛传播,自然疫源地是深圳市散发广州管圆线虫患者的主要原因.

Study on the epidemiological characteristics and natural infectious focus of Angiostrongylus cantonensis in Shenzhen area of Zhujiang Delta in China

Objective To delimit the natural infectious focus, including the distribution of wildlife,species, ecology of intermediate hosts and final host of Angiostrongylus cantonensis, as well as the routes of transmission and epidemiological characteristics and wildlife of human Angiostrongylus cantonensis, based on human diverging cases identified in Shenzhen, southern area of China. Methods Data including rate of infection and density of Angiostrongylus cantonensis among different hosts in 12 different areas in Shenzhen was collected, using microscope to inspect homogenate liquids of snails. Wild mice were captured with mouse cage to examine the adult Angiostrongylus cantonensis. Using larva isolated from wild-snails-infected rats to observe the life cycle of Angiostrongylus cantonensis. Results Wild life of Angiostrongylus cantonensis existed in the southwest part of Shenzhen with its majority intermediate hosts as Achatina fulica. The overall rate of infection was 31% in wildlife and final host was found to be Rattus andersoni, Achatina fulica which were extensively distributed in the shrub region of Shenzhen because of suitable climate,humidity and vegetation for generating the life cycle of Achatina fulica. Human infected Angiostrongylus cantonensis was mainly due to eating raw snails or vegetables contaminated by larva of Angiostrongylus cantonensis.The peak of infection was seen from April to November in Shenzhen area.Conclusion Wildlife of Angiostrongylus cantonensis existed in the southwest part of Shenzhen with major wildlife reservoir including fresh water snail and wild mouse. The existence of natural focus Angiostrongylus cantonensis was now recognized as an important source of human angiostrongliasis in Shenzhen area.