目的 了解2016—2019年贵州省国家监测点土源性线虫人群感染情况,为全省制订防治策略提供科学依据。 方法 2016—2019年在贵州省9市（州）设立土源性线虫病国家监测点,每年固定监测点8个,流动监测点5~7个。各监测点以县为单位,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个行政村开展监测。每个行政村整群随机抽取3岁及以上常住居民不少于200人,每个监测点不少于1 000人。收集调查对象粪样,采用改良加藤厚涂片法（一粪二检）查虫卵,3~9周岁儿童加做透明胶纸肛拭法检测蛲虫卵。每年在3个土源性线虫病固定监测点每个村中随机抽取5户家庭,采用改良饱和硝酸钠漂浮法检测居民居所附近的田地或菜园土壤中蛔虫卵污染情况,并用盐水分离法进行钩蚴鉴定。采取问卷调查方法,收集监测点的地理环境、经济水平和卫生状况等自然和社会因素信息。分析比较不同监测点、性别、年龄、职业等人群的土源性线虫感染率,率的比较采用卡方检验。 结果 2016—2019年贵州省每年设立13~15个国家级监测点,各监测点生产方式均以农业为主,饮用水以自来水为主。人均年收入为4 911~6 686元。2016—2019年无害化厕所覆盖率分别为56.3%（36 861/65 520）、40.0%（21 327/53 285）、59.6%（37 992/63 802）和59.5%（37 679/63 333）。累计调查56 598人,土源性线虫总感染率为4.9%（2 765/56 598）,2016—2019年分别为8.6%（1 130/13 158）、5.2%（776/15 069）、3.9%（547/14 220）、2.2%（312/14 151）,呈逐年下降趋势,各年间感染率比较差异有统计学意义（χ² = 642.31,P < 0.01）。蛔虫、钩虫、鞭虫和儿童蛲虫平均感染率分别为2.5%（1 415/56 598）、1.2%（674/56 598）、1.7%（936/56 598）和 1.6%（130/8 158）,均以轻度感染为主。9市（州）中,黔东南州人群土源性线虫感染率最高,为8.2%（908/11 086）,不同地区感染率差异有统计学意义（χ² = 824.55,P < 0.01）。男性、女性的土源性线虫感染率分别为4.7%（1 322/28 286）、5.1%（1 443/28 312）,差异有统计学意义（χ² = 5.45,P < 0.05）。不同年龄组中,≥ 70岁年龄组土源性线虫感染率最高,为6.3%（270/4 276）（χ² = 98.04,P < 0.01）。不同民族人群感染率不同,以其他少数民族最高,为8.4%（267/3 182）（χ² = 441.19,P < 0.01）。职业分布中,学生的感染率最高,为5.6%（987/17 612）（χ² = 121.65,P < 0.01）。不同文化程度中,文盲的感染率最高,为7.0%（406/5 804）（χ² = 279.00,P < 0.01）。4年共检测田地和菜园土壤300份,检出人蛔虫卵阳性75份,阳性率为25.0%（75/300）,4年土壤中人蛔虫卵阳性率分别为36.0%（27/75）、26.7%（20/75）、25.3%（19/75）和12.0%（9/75）,差异有统计学意义（χ² = 11.72,P < 0.01）,未检出钩蚴。结论 2016—2019年贵州省国家监测点居民土源性线虫感染率呈下降趋势,以蛔虫和鞭虫感染为主。女性、≥ 70岁年龄组、学生、文盲、其他少数民族及黔东南地区居民为重点关注人群。

Objective To understand the infection status of soil-transmitted nematodes at national surveillance sites in Guizhou Province from 2016 to 2019, and to provide a scientific basis for formulating prevention and control strategies. Methods From 2016 to 2019, the national surveillance sites of soil-transmitted nematodes were established in 9 cities (prefectures) of Guizhou Province, with 8 fixed surveillance sites and 5~7 mobile surveillance sites every year. Each surveillance site was county-based, and was divided into five areas according to the geographical location, including east, west, south, north, and mid areas. In each area, one administrative village was randomly selected from one township for conducting surveillance, No less than 200 permanent residents at 3 years of age and above were randomly selected from each administrative village, and no less than 1 000 residents were selected from each surveillance site. Fecal samples of residents were collected and examined for nematode eggs of intestinal with the modified Kato-Katz method(two slide-reading for each sample). Children aged 3~9 years were examined with cellophane anal swab to detect Enterobius vermicularis eggs. Five families were randomly selected from each village at three fixed surveillance sites every year. The modified saturated sodium nitrate floating method was used to detect the soil contamination of Ascaris eggs in fields or vegetable gardens near the residents’ houses, and the saltwater separation method was used for identification of hookworm larvae in the soil samples. Questionnaire survey was performed to collect the information of natural and social factors including geographical environment, economic level and health status of the surveillance sites. The infection rates of soil transmitted nematodes and the proportion of participant, gender, ages and occupations in different surveillance sites were analyzed and compared with Chi square test. Results From 2016 to 2019, Guizhou Province set up 13~15 national surveillance sites every year; the production mode of each surveillance site was mainly agriculture, and the drinking water was mainly tap water; the per capita annual income was 4 911-6 686 yuan; the coverage rates of sanitary toilets were 56.3% (36 861/65 520), 40.0% (21 327/53 285), 59.6% (37 992/63 802) and 59.5% (37 679/63 333), respectively. A total of 56 598 residents were investigated, and the overall infection rate of soil-transmitted nematodes was 4.9% (2 765/56 598). From 2016 to 2019, the infection rate by year was 8.6% (1 130/13 158), 5.2% (776/15 069), 3.9% (547/14 220) and 2.2% (312/14 151), respectively, showing a decreasing trend year by year, with the difference between years being statistically significant (χ² = 642.31, P < 0.01). The average infection rates of Ascaris lumbricoides, hookworm, Truchuris trichiura and Enterobius vermicularis in children were 2.5% (1 415/56 598), 1.2% (674/56 598), 1.7% (936/56 598) and 1.6% (130/8 158), respectively, maily of mild infection. Among the 9 cities (prefectures), the infection rate of soil-transmitted nematodes in Qiandongnan prefecture was highest, which was 8.2% (908/11 086) (χ² = 824.55, P < 0.01). The average infection rate of nematodes in males and females was 4.7% (1 322/28 286) and 5.1% (1 443/28 312), respectively, and the difference was significant (χ² = 5.45, P < 0.05). Among the age groups, the infection rate was highest in the group over 70 years old, at 6.3% (270/4 276) (χ² = 98.04, P < 0.01). The infection rate varied among ethnic groups, and minority ethnic groups had the highest infection rate, at 8.4% (267/3 182) (χ² = 441.19, P < 0.01). The occupation distribution showed that the infection rate was highest in students, at 5.6% (987/17 612) (χ² = 121.65, P < 0.01). Among educational groups, the infection rate was highest among illiterate people, at 7.0% (406/5 804) (χ² = 279.00, P < 0.01). The infection rate varied among ethnic groups, and minority ethnic groups had the highest infection rate, at 8.4% (267/3 182) (χ² = 441.19, P < 0.01). During the four years, 300 soil samples were collected from fields and vegetable gardens, among them 75 samples were positive of Ascaris eggs with a positive rate of 25.0% (75/300). The soil positive rates of Ascaris eggs in 2016—2019 were 36.0% (27/75), 26.7% (20/75), 25.3% (19/75) and 12.0% (9/75), respectively (χ² = 11.72, P < 0.01). No hookworm larva was detected. Conclusion From 2016 to 2019, the infection rate of soil-transmitted nematodes decreased in residents of national surveillance sites of Guizhou Province, maily the infection of Ascaris and Trichuris. Close attention should be paid to groups of females, over 70 years old, students, the illiteracy, other ethnic minorities and residents in southeast of Guizhou.