一起由毒刺蛾幼虫引起的皮疹暴发调查

Investigation of a dermatitis outbreak caused by poisonous eucleid caterpillars

目的近年来随着环境和气候的变化,毒刺蛾幼虫皮炎暴发疫情增多,通过本次调查确定病因,查清发病的危险因素和接触途径。方法对出现症状的村民进行现场个案及环境调查,描述病例的流行病学特征,按照2∶1比例进行病例对照研究,并请专家鉴定虫的种类。结果发病率71.70%（223/311）,年龄最大的（〉80岁）和年龄最小的（〈9岁）人群罹患率最高,该村的罹患率高于外村,村北的罹患率高于村南,村西的罹患率高于村东,环境调查发现村西北角富润江边一棵枫杨树上孳生大量的毛虫,经专家鉴定为毒刺蛾幼虫。病例对照分析结果显示,4个因素与发病有关,即路过枫杨树（≥4次/d）（OR=12.0,95%CI：3.9~51.0）、用江水搽身体（OR=10.0,95%CI：1.5~448.0）、用江水洗菜洗衣服（OR=4.5,95%CI：1.4~19.0）和在江中游泳（OR=6.6,95%CI：1.5~62.0）。结论该疫情为一起由毒刺蛾幼虫引起的皮疹病例暴发,茶毛虫毒毛除可随风飘散接触人体皮肤引起疾病外,也可通过污染水源接触人体皮肤导致发病并引起暴发。

Objective With the changes in environment and climate in recent years, the dermatitis outbreaks, caused by poisonous eucleid caterpillars, has increased. This investigation aims to determine the cause of this disease and find out the risk factors and route of exposure. Methods A case study and an environmental survey were carried out among the villagers with symptoms, and the epidemiologieal characteristics of cases were described. A case- control study （2 ： 1） was performed, and experts were invited to identify the species of caterpillars. Results The attack rate （AR） in the village was 71.70% （223/311）, highest among villagers over 80 years of age and those under 9 years of age. The AR in the village was higher than those in other villages. In the village, the AR was higher in the northern part than in the southern part and higher in the western part than in the eastern part. The environmental survey showed that a large number of caterpillars bred on a Pterocarya stenoptera tree near the Furun River at the northwestern comer of the village, and the experts identified the caterpillars as poisonous eucleid caterpillars. The case-control study showed that the risk factors for dermatitis caused by poisonous eucleid caterpillars were walking past the tree （〉~4 times/d） （OR= 12.0, 95% CI： 3.9-51.0）, washing the body with river water （OR= 10.0, 95% CI： 1.5-448.0）, washing vegetables and clothes with river water （OR=4.5, 95%CI： 1.4-19.0）, and swimming in the river （OR=6.6, 95%CI- 1.5-62.0）. Conclusion The outbreak of dermatitis was caused by poisonous eucleid caterpillars, whose poisonous hair might contact the human skin by moving with wind or contaminating water.