2011-2015年贵州省土源性线虫感染监测结果分析

Surveillance results of national monitoring site for soil-transmitted nematode infections in Guizhou Province in 2011-2015

目的了解贵州省2011-2015年监测点居民土源性线虫感染情况。方法2011-2015年分别从贵州省普定县东、南、西、北、中5个片区选取马官镇田官村、坪上乡大哪村、化处镇水母村、城关镇青山村、坪上镇坪上村作为监测点,每年对其中的一个行政村开展土源性线虫感染情况监测,收集3岁以上常住居民的粪便,采用改良加藤厚涂片法查虫卵,透明胶纸肛拭法查3~12岁儿童蛲虫(Enterobius vermicularis)卵。改良饱和硝酸钠漂浮法检查居民居所附近的菜园、厕所周边、庭院和厨房等4种环境类型土壤中蛔虫(Ascaris lumbricoides)卵污染的情况。分析比较不同性别、年龄、职业等人群土源性线虫感染率,率的比较采用χ~2检验。结果 2011-2015年累计检查5 035人,土源性线虫感染率分别为14.24%(143/1 004)、15.72%(161/1 024)、12.29%(123/1 001)、15.38%(156/1 001)、32.44%(326/1 005);蛔虫、钩虫(Ancylostoma sp.)、鞭虫(Trichuris trichiura)和儿童蛲虫的平均感染率为11.40%(574/5 035)、0.62%(31/5 035)、9.33%(470/5 035)和1.01%(14/1 381)。男性、女性土源性线虫平均感染率分别为18.28%(473/2 588)、17.82%(436/2 447),差异无统计学意义(χ~2=0.15,P>0.05)。不同年龄组中,10~岁组土源性线虫感染率最高,为23.25%(381/1 639)(χ~2=62.59,P<0.05)。职业分布中,学生的感染率最高,为22.46%(524/2 333)(χ~2=58.43,P<0.05)。小学文化程度的人感染率最高,为21.41%(455/2 125)(χ~2=39.19,P<0.05)。苗族人群的感染率明显高于汉族及其他少数民族,为44.99%(220/489)(χ~2=267.70,P<0.05)。2011-2015年共检测不同环境类型土壤200份,人蛔虫卵阳性86份,阳性率为43%(86/200);其中,菜园与厕所周边的活受精蛔虫卵检出率最高,分别为26%(13/50)与20%(10/50);厨房的检出率最低,为2%(1/50);4种环境类型土壤中人蛔虫卵的污染情况差异有统计学意义(χ~2=12.71,P<0.05)。结论 2011-2015年监测点居民土源性线虫感染率仍处于较高水平,以蛔虫和鞭虫感染为主。10~20岁人群、学生、小学文化程度及苗族人群的土源性线虫感染率高于其他人群。居民住所的环境土壤受到不同程度的人蛔虫卵污染。

Objective To understand the infection status of soil-transmitted nematodes at the national monitoring site for soil-transmitted nematode infections in Guizhou Province during 2011-2015. Methods From 2011 to 2015, Tianguan Village of Maguan Town, Dana Village of Pingshang Township, Shuimu Village of Huachu Town, Qingshan Village of Chengguan Town and Pingshang Village of Pingshang Town were selected from the eastern, southern, western, northern, middle parts of Puding County, respectively, as the national monitoring sites for soil- transmitted nematode infections. Surveillance of soil-transmitted nematode infections was performed in one of these villages in each year. Fecal samples from residents aged over 3 were collected and eggs of intestinal nematodes were examined with the Kato-Katz method. The transparent adhesive tape test was used to examine Enterobius vermicularis eggs among children of 3-12 years. A modified floatation test with saturated sodium nitrate was used to detect Ascaris eggs in soil of vegetable field, around lavatory, courtyard and kitchen. The infection rate among residents was analyzed in aspects of gender, age and occupation with Chi square test. Results A total of 5 035 residents were examined from 2011 to 2015, with a soil-transmitted nematode infection prevalence of 14.24% （143/1 004）, 15.72% （161/1 024）, 12.29% （123/l 001）, 15.38% （156/1 001） and 32.44% （326/1 005）, respectively. The prevalence of A. lumbricoides （roundworm）, Ancylostoma sp. （hookworm）, T. trichiura （whipworm） and E. vermicularis （pinworm） in children were 11.40%（574/5 035）, 0.62%（31/5 035）, 9.33%（470/5 035） and 1.01%（14/1 381）, respectively. There was no significant difference in the rate of soil-transmitted nematode infection between males （18.28%, 473/2 588） and females （17.82%, 436/2 447） （X^2 = 0.15, P〉 0.05）. Among different age groups, the infection rate was highest in the 10- year group （23.25%, 381/1 639; X^2 = 62.59, P 〈 0.05）. Among different occupations, the infection rate was highest in students （22.46%, 524/2 333; X^2 = 58.43, P 〈 0.05）. Among different degrees of education, the infection rate was highest in those with primary school education （1.41%, 455/2 125; X^2 = 39.19, P 〈 0.05）. Among different ethnicities, the Miao ethnicity presented higher infection rate （44.99%, 220/489; X^2 = 267.70, P 〈 0.05） than Han and other minorities. Of the 200 soil samples tested from 2011 to 2015, 86 were positive for A. lumbricoides eggs, with a positive rate of 43%. The detection rate of live fertilized Ascaris eggs was highest in soil samples of vegetable field （26%, 13/50） and around lavatory （20%, 10/50）, and lowest in those of the kitchen （2%, 1/50）, with a significant difference among the four types of soil （X^2 = 12.71, P 〈 0.05）. Conclusion From 2011 to 2015, the infection rate of soil transmitted nematodes was still at a high level, mostly roundworm and whipworm. The infection was more significant among people aged 10-20, students, people with primary school education, and the Miao ethnicity. The soils of the living environment showed different degrees of contamination by Ascaris eggs.