2016—2020年河南省土源性线虫感染监测结果分析

Analysis of surveillance on soil-transmitted helminth infection in Henan Province from 2016 to 2020

目的了解河南省土源性线虫的感染现状和防治效果,为制定防治对策提供依据。方法2016—2020年按照《全国肝吸虫病和土源性线虫病监测方案(试行)》要求,全省以县为单位设立监测点。各监测点按地理方位划分为东、西、南、北、中等5个片区,每片区随机抽取1个乡(镇)的1个行政村为监测点,每个行政村整群抽取3周岁以上常住居民不少于200人为监测对象,每个监测县(市、区)监测人数不少于1000人。采集监测对象粪样,采用改良加藤厚涂片法(Kato-Katz法)检测土源性线虫(钩虫、蛔虫、鞭虫)感染情况,试管滤纸培养法鉴定钩虫虫种,计算感染率。感染率间比较采用卡方检验。结果2016—2020年,在河南省98个土源性线虫病监测点累计检测101254人次,检出土源性线虫感染139例,总感染率为0.14%。不同年份人群土源性线虫总感染率均处于1.0%以下水平(0.08%~0.19%),感染率差异有统计学意义(χ^(2)=9.797,P<0.05);线性趋势检验结果显示,人群土源性线虫的总感染率随着年份变化无统计学意义(χ^(2)=1.304,P>0.05)。所监测的18个地市及6个省直管县中,感染率居前3位的分别为漯河市(0.46%,19/4097)、南阳市(0.31%,32/10280)和济源示范区(0.28%,3/1073),另有7市(省直管县)未发现感染者。男性和女性土源性线虫总感染率分别为0.14%(65/47795)和0.14%(73/53459)。不同性别人群钩虫、蛔虫、鞭虫及土源性线虫感染率(男性:0.07%、0.05%、0.02%、0.14%,女性:0.07%、0.05%、0.01%、0.14%)差异均无统计学意义(χ^(2)=0.117、0.001、0.526、0.001,均P>0.05)。各年龄组均有感染,土源性线虫感染率以≥71岁年龄组最高,为0.41%(27/6603);钩虫感染率以≥71岁年龄组最高,为0.24%(16/6603);蛔虫感染率以61~70岁年龄组最高,为0.10%(13/13408);鞭虫感染率以≥71岁年龄组最高,为0.09%(6/6603)。各年龄组土源性线虫、钩虫、蛔虫、鞭虫的感染率差异均有统计学意义(χ^(2)=83.585、69.061、16.269、26.559,P<0.01或P<0.05)。职业分布中以农民感染率最高,为0.2%(104/52276);不同文化程度中以文盲或半文盲人群感染率最高,为0.14%(106939)。不同职业、文化程度人群土源性线虫总感染率的差异均有统计学意义(χ^(2)=32.330、20.014,均P<0.01);不同职业、文化程度人群的钩虫感染率差异有统计学意义(χ^(2)=31.103、16.605,均P<0.01),蛔虫、鞭虫感染率差异均无统计学意义(χ^(2)=6.383、4.658和2.819、9.366,均P>0.05)。结论2016—2020年河南省监测人群土源性线虫感染率较低,并呈散发状态,≥61岁年龄组、职业为农民、文化程度为小学、初中、文盲或半文盲的人群应为防治重点人群。

Objective To understand the current status of soil-transmitted helminth(STH)infection and control effect in Henan Province,for providing basis for formulating prevention and control countermeasures.Methods From 2016 to 2020,surveillance sites were set up in selected counties in Henan Province,according to the National Surveillance Program for Liver Fluke Diseases and Soil-transmitted Nematodes(Pilot).The surveillance counties were selected from five areas(east,west,south,north and central)of the province.From each of the areas,a township was randomly selected,and then an administrative village was selected from each township as the surveillance site.Over 200 permanent residents above 3 years old were cluster sampled from each administrative village and no less than 1000 residents were included in each surveillance county.Fecal samples were collected from the participants for examining and counting STH eggs using modified Kato-Katz thick smear method to calculate infection rate.Hookworm egg positive samples were further identified for species by test tube-filter paper culture method.The infection rate between groups was compared by the Chi-square test.Results A total of 101254 participants were enrolled in the surveillance from 98 surveillance sites,of them,139 were found STH positive,with an overall infection rate of 0.1%in Henan Province.The total infection rate of STH in each year was below 1.0%(0.08%-0.19%),and the difference was statistically significant(χ^(2)=9.797,P<0.05).The linear trend test showed that the total infection rate of STH has no significant difference(χ^(2)=1.304,P>0.05).Among the 18 cities and 6 counties,the top infection rates were seen in Luohe(0.46%,19/4097),Nanyang(0.31%,32/10280)and Jiyuan Demonstration Zone(0.28%,3/1073),and no infection was found in 7 cities(counties).The infection rates of STH in males and females were 0.14%(65/47795)and 0.14%(73/53459).There were no significant differences in hookworm,Ascaris lumbricoides,Trichuris trichiura and total infection rates among different genders(male:0.07%,0.05%,0.02%,0.14%;female:0.07%,0.05%,0.01%,0.14%)(χ^(2)=0.117,0.001,0.526,0.001;P>0.05).The infection occurred in all age groups,with the highest infection rate in the group aged≥71 years of 0.4%(27/6603).The hookworm infection rate was the highest among the≥71 years age group,at 0.24%(16/6603).The infection rates of soilborne nematodes,hookworm,A.lumbricoides,T.trichiura among different age groups were statistically significant(χ^(2)=83.585,69.061,16.269 and 26.559;P<0.01 or P<0.05).Among different occupation groups,farmers had the highest infection rate at 0.2%(104/52276).Among different education groups,the illiteracy or semiilliteracy group had the highest infection rate at 0.14%(10/6939).There were significant differences in the infection rate among different ages,occupations and educational background(χ^(2)=83.585,32.330,20.014;P<0.01).There were significant differences in hookworm infection rates among people of different occupations and cultures(χ^(2)=31.103 and16.605,P<0.01),but there were no significant differences in A.lumbricoides,T.trichiura infection rates among the groups(χ^(2)=6.383,4.658,2.819,9.366;P>0.05).Conclusion From 2016 to 2020,the infection rate of STH in Henan Province decreased significantly and remained at a considerably low level,showing sporadic distribution.Residents at age 61 and above,farmers,people with the education of primary or middle school,illiterate or semiilliterate are the main targets of control program.