浙江省江山市一起阿米巴痢疾暴发的流行病学调查

Epidemiological Investigation on an Outbreak of Amoebic Dysentery in Jiangshan City of Zhejiang Province

2006年5月对浙江省江山市某镇2所学校学生及其在学校及家庭密切接触者中的腹泻患者进行流行病学个案调查和粪检,并随机抽检学校自来水和患者家庭井水进行微生物指标检测。本次阿米巴痢疾暴发起止时间为2006年5月10日～6月5日,经病原学检测溶组织内阿米巴原虫阳性31例,其中学生/幼托儿童23例(占74.2%),另8例为散居儿童、农民及个体户。病例主要分布在六一幼儿园(9例)和贺村中心小学(8例),罹患率分别为7.4%(9/122)和0.7%(8/1229),其他学校为散在病例。594名密切接触者中检出包囊携带者9例,携带率为1.5%。问卷调查显示,31例患者中,22例饭前便后均不洗手,14例与本次患病者有密切接触史。两所学校自来水和10例发病者家庭井水样品中7份样品的大肠埃希菌指标超过国家标准(≥50),但均无溶组织内阿米巴滋养体或包囊污染。

The investigation was carried out from 15 May to 10 June 2006 among diarrhea patients of two schools and periphery residents in Hecun Town, Jiangshan City. Stool samples were examined for Entamoeba histolytica. Water samples were taken for microbial analysis. 31 cases with E. histolytica were found,with 74.2% （23 cases） of students and preschool children. 9 cases were found in Liuyi kindergarten and 8 cases in Hecun central primary school, with a prevalence of 7.4% and 0.65%, respectively. Among 594 asymptomatic close contactors, 9 cases （1.5%） were carriers of cysts. Of the 31 cases, 22 were found with no habit of handwashing before eating or after defecation, and 14 cases had a close contact to the patients. No amoebic cysts or trophozoites were found from 12 water samples collected from schools or patient′s houses, but the Esherichia coli level exceeded the national standard in 7 samples.