广东省首次广州管圆线虫感染局部暴发的流行病学调查

目的了解一起外来民工集体感染广州管圆线虫疫情的流行因素。方法对广宁县文坑村疑似广州管圆线虫感染的云南白族民工、其他民工和当地居民进行现场流行病学调查;采集疑似病人和部分民工血清检测广州管圆线虫抗体;在疫点及周围捕捉老鼠,采集福寿螺、东风螺和新鲜鼠粪进行病原学检查。结果2007年3月24日17名云南白族民工共同进食在居住地附近的田地里采集的福寿螺,其中先后有6人发病,罹患率为35.29%(6/17),全部患者均进食过生螺肉。仅捕获黄胸鼠1只,未发现广州管圆线虫感染;采集新鲜鼠粪8份,其广州管圆线虫感染率为75%(6/8)。检查福寿螺189只,平均感染率为2.12%(4/189),感染度为平均每只螺含37条广州管圆线虫幼虫,其中大福寿螺的感染率较高,为21.43%(3/14);未采集到东风螺。采集5份患者和2份无症状民工的血清,其中2份患者血清的广州管圆线虫抗体呈弱阳性。结论广宁县横山镇文坑村是广州管圆线虫病的重要自然疫源地。外来民工同吃生福寿螺是引起广州管圆线虫感染局部暴发的主要因素。

The first local outbreak of angiostrongylus cantonensis infection in Guangdong province

Objective To analyse the epidemiologic characteristics of a mass angiostrongylus cantonensis infection among migrant peasant workers from Yunnan.Methods An epidemiological investigation was carried out among migrant peasant workers from Yunnan Bai ethnicity,other peasant workers and local residents at Wenkang village in Guangning County.Serum specimens were collected to detect angiostrongylus cantonensis infection.Mice and its feces,pomacea canaliculata were also examined to find pathogenic clues.Results 6 of 17 workers with common history of eating undercooked pomacea canaliculata,were fallen ill and the incidence rate was 35.29%(6/17).No first stage larvae of A.cantonensis was found in a R.flavipectus caught but in feces of the rodents observed the infection rate of 75%(6/8).The average infection rate of the third stage larvae was 2.12%(4/189) among 189 P.canaliculata,of which the big ones was 21.43%(3/14).Serological analysis showed two patients had positive anti-A.cantonensis antibody.Conclusion Eating undercooked P.canaliculata caused outbreak of A.cantonensis infection among migrant Yunnan workers in Wenkang village of Guangning county which was confirmed a natural focus.