2015—2021年江西省人群土源性线虫感染流行趋势分析

Epidemiological trends of soil-transmitted nematode infections in Jiangxi Province,2015—2021

目的了解和分析2015—2021年江西省土源性线虫病流行态势与变化趋势,为制订土源性线虫病传播控制与阻断策略、评价防治效果提供科学依据。方法2015—2021年,江西省分别选取13、86、86、86、86、24和24个县(市、区)设立土源性线虫病国家监测点与省级监测点,各监测点按地理方位划分为东、西、南、北、中等5个片区,每个片区随机抽取1个乡(镇)的1个行政村,整群抽取3周岁以上常住居民为监测对象。收集监测对象粪样,采用改良加藤厚涂片法(一粪二检)检查土源性线虫感染情况,计算各虫种感染率和感染度,并分析不同生态区土源性线虫感染情况。收集2015—2021年《江西统计年鉴》全省农村居民可支配收入相关数据,采取问卷调查从监测村村委会收集卫生厕所建设等信息,分析土源性线虫感染率与居民可支配收入和卫生厕所覆盖率的相关性。感染率和构成比的比较采用卡方检验,相关性研究采用Pearson相关性分析。结果2015—2021年,江西省监测人群土源性线虫感染率分别为1.8%(126/7137)、1.3%(947/71766)、1.1%(803/70547)、0.9%(604/69507)、0.9%(628/69620)、0.7%(151/21884)和0.9%(202/21757),呈逐年下降趋势,各年度之间感染率差异有统计学意义(χ^(2)=158.639,P<0.01)。2015—2021年,钩虫感染率分别为1.1%(82/7137)、0.6%(466/71766)、0.6%(450/70547)、0.5%(336/69507)、0.5%(362/69620)、0.4%(98/21884)和0.7%(148/21757);蛔虫感染率分别为0.3%(24/7137)、0.5%(393/71766)、0.4%(287/70547)、0.3%(221/69507)、0.3%(225/69620)、0.2%(40/21884)和0.2%(42/21757);鞭虫感染率分别为0.3%(21/7137)、0.2%(125/71766)、0.1%(74/70547)、0.1%(57/69507)、0.1%(49/69620)、0.1%(13/21884)和0.1%(14/21757)。钩虫、蛔虫和鞭虫各年度之间感染率差异均有统计学意义(χ^(2)=75.456、112.506、75.383,均P<0.01)。2015—2021年男性土源性线虫感染率分别为2.0%(73/3623)、1.3%(469/35788)、1.1%(378/35207)、0.8%(273/34703)、0.9%(295/34801)、0.6%(65/11110)和0.8%(88/10620),女性感染率分别为1.5%(53/3514)、1.3%(478/35978)、1.2%(425/35340)、1.0%(331/34804)、1.0%(333/34819)、0.8%(86/10774)和1.0%(114/11137),男、女性各年度之间感染率差异有统计学意义(χ^(2)=122.146、49.615,均P<0.01);仅2018年男女性别之间感染率差异有统计学意义(χ^(2)=5.450,P<0.05)。2015—2021年均以≥70岁年龄组人群土源性线虫感染率最高,分别为3.4%(19/554)、2.3%(129/5559)、2.1%(127/5965)、2.0%(129/6507)、1.7%(119/7105)、1.3%(36/2811)和2.1%(68/3177),各年度各年龄组之间土源性线虫感染率差异均有统计学意义(χ^(2)=39.763、150.459、212.140、219.129、132.674、43.997、115.627,均P<0.01)。2015—2021年钩虫重度感染者分别占钩虫感染者总数的1.2%(1/82)、3.9%(18/466)、1.3%(6/450)、1.5%(5/336)、0.3%(1/362)、2.0%(2/98)和5.4%(8/148),各年度之间构成比差异有统计学意义(χ^(2)=22.853,P<0.01);仅2016年检出蛔虫重度感染者,占蛔虫感染者总数的1.0%(4/393);仅2015年检出鞭虫重度感染者,占鞭虫感染者总数的4.8%(1/21)。2016—2017、2019—2021年均以浙闽山地丘陵生态区的土源性线虫感染率最高,分别为2.3%(316/13852)、1.5%(217/14402)、1.4%(194/14063)、1.2%(69/5527)和1.1%(60/5535),2015、2018年分别以湘赣丘陵山地生态区、长江中下游平原生态区最高,为2.5%(63/2471)和1.2%(234/18883);各年度不同生态区之间感染率差异有统计学意义(χ^(2)=21.112、156.920、67.104、73.315、73.493、37.022、9.351,均P<0.01或0.05)。2015—2021年江西省全省农村居民可支配收入分别为10117、11139、12138、13242、14460、15796和16981元,监测村卫生厕所覆盖率分别为82.7%(200994/243000)、85.7%(256437/299398)、87.3%(257553/294951)、88.9%(250381/281699)、92.1%(69428/75380)和93.8%(77259/82376),2015—2021年土源性线虫感染率与全省农村居民可支配收入呈负相关(r=-0.834,P<0.05),而与监测村无害化厕所覆盖率无相关性(r=-0.799,P>0.05)。结论2016—2021年江西省人群土源性线虫感染率总体逐年下降,呈低度流行态势,其中41个县土源性线虫感染率连续3年降至1.0%以下。

ObjectiveTo understand and analyze the endemic status and transmission trends of soil-transmitted helminth(STH)infection in Jiangxi Province during 2015—2020 to provide scientific basis for formulating strategy of transmission control and interruption,and evaluate the control effect.MethodsFrom 2015 to 2021,13,86,86,86,86,24 and 24 counties(cities and districts)in Jiangxi Province were selected as national surveillance sites and provincial surveillance sites.The surveillance sites were randomly selected from five geographical sections in the east,west,south,north and center,from each section,one administrative village in one township(town)was randomly selected as surveillance site.Fecal samples were collected from each enrolled participant and examined for STH eggs(two slide-reading each sample)using the modified Kato-Katz thick smear method.The infection rate and intensity of different worm species were calculated,and the infection prevalence in different eco-region was analyzed.The disposable income data of rural residents in Jiangxi Province were collected from Jiangxi Statistical Yearbook from 2015 to 2021.A questionnaire based survey was conducted to collect information on the construction of sanitary toilets in each surveillance site from the village committee from 2016 to 2021.The infection rate and constituent ratio were compared by the Chi-square test.The correlation study was conducted using Pearson correlation analysis.ResultsFrom 2015 to 2021,the infection rates of STH were 1.8%(126/7137),1.3%(947/71766),1.1%(803/70547),0.9%(604/69507),0.9%(628/69620),0.7%(151/21884)and 0.9%(202/21757)respectively,showing a decreasing trend year by year,with statistically significant differences in infection rates between years(χ^(2)=158.639,P<0.01).From 2015 to 2021,the infection rates of hookworm were 1.1%(82/7137),0.6%(466/71766),0.6%(450/70547),0.5%(336/69507),0.5%(362/69620),0.4%(98/21884)and 0.7%(148/21757)respectively.From 2015 to 2021,the infection rates of Ascaris lumbricoides were 0.3%(24/7137),0.5%(393/71766),0.4%(287/70547),0.3%(221/69507),0.3%(225/69620),0.2%(40/21884)and 0.2%(42/21757)respectively.From 2015 to 2021,the infection rates of Trichuris trichiura were 0.3%(21/7137),0.2%(125/71766),0.1%(74/70547),0.1%(57/69507),0.1%(49/69620),0.1%(13/21884)and 0.1%(14/21757)respectively.The infection rates of hookworm,A.lumbricoides and T.trichiura were significantly different between years(χ^(2)=75.456,112.506,75.383,all P<0.01).From 2015 to 2021,the infection rates were 2.0%(73/3623),1.3%(469/35788),1.1%(378/35207),0.8%(273/34703),0.9%(295/34801),0.6%(65/11110)and 0.8%(88/10620)in males and 1.5%(53/3514),1.3%(478/35978),1.2%(425/35340),1.0%(331/34804),1.0%(333/34819),0.8%(86/10774)and 1.0%(114/11137)in females.The infection rates of male and female were significantly different between years(χ^(2)=122.146,49.615,P<0.01).The infection rates of female were statistically higher than that of males in 2018(χ^(2)=5.450,P<0.05).From 2015 to 2021,the infection rates of soil-transmitted nematodes were the highest in the over-70-year-old age group,which were 3.4%(19/554),2.3%(129/5559),2.1%(127/5965),2.0%(129/6507),1.7%(119/7105),1.3%(36/2811)and 2.1%(68/3177)respectively,with statistically significant differences in infection rates among the different age groups(χ^(2)=39.763,150.459,212.140,219.129,132.674,43.997,115.627,P<0.01).From 2015 to 2021,the severely infected accounted for 1.2%(1/82),3.9%(18/466),1.3%(6/450),1.5%(5/336),0.3%(1/362),2.0%(2/98)and 5.4%(8/148)of the total hookworm infected villagers,respectively.The differences of constituent ratio in each year were statistically significant(χ^(2)=22.853,P<0.01).Severe A.lumbricoides infection was only detected in2016,accounting for 1.0%(4/393)of the total A.lumbricoides infection cases.T.trichiura severe infection were only detected in 2015,accounting for 4.8%(1/21)of the total T.trichiura infection cases.The infection rates of STH in 2016—2017 and 2019—2021 were the highest in Zhejiang-Fujian mountain and hill ecological regions.They were 2.3%(316/13852),1.5%(217/14402),1.4%(194/14063),1.2%(69/5527)and 1.1%(60/5535)respectively.In 2015 and 2018,the highest infection rates were 2.5%(63/2471)and 1.2%(234/18883)in Hunan-Jiangxi hill and mountain and Yangtze River basin ecological region,respectively.The differences in infection rates among different ecological regions in each year were statistically significant(χ^(2)=21.112,156.920,67.104,73.315,73.493,37.022,9.351,P<0.01 or P<0.05).From 2015 to 2021,the disposable income of rural residents in Jiangxi Province were 10117,11139,12138,13242,14460,15796 and 16981 yuan and the coverage rates of sanitary latrines in surveillance villages were 82.7%(200994/243000),85.7%(256437/299398),87.3%(257553/294951),88.9%(250381/281699),92.1%(69428/75)and 93.8%(77259/82376),respectively.The infection rates of soiltransmitted nematodes in Jiangxi Province were negatively correlated with the disposable income data among the rural residents(r=-0.834,P<0.05)while were no correlation with the coverage rate of sanitary latrines in surveillance villages(r=-0.799,P>0.05)in Jiangxi Province during 2016—2021.ConclusionThe infection rate of STH in Jiangxi Province in 2016—2021 shows an overall decline year by year,suggesting a low transmission trend.The infection rate in 41 counties has reduced to below 1.0%for 3 consecutive years.