目的 了解我国人体土源性线虫感染情况，为评估各省（直辖市、自治区）土源性线虫病监测工作开展情况、改进和完善防治策略提供支持。方法 2020年在全国31个省（直辖市、自治区）的408个人体土源性线虫病国家监测点开展监测工作。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，每个片区抽取1个乡（镇）的1个行政村3周岁以上的常住居民200人，每个监测点共计调查1 000人。采集被调查者粪样，采用改良加藤厚涂片法（一粪二检）检查钩虫、蛔虫、鞭虫和蛲虫的感染情况，并分别计算感染率和感染度。采集调查点每个行政村田地或菜园土样，采用45 ℃、5%盐水鉴定土壤中钩蚴，采用饱和硝酸钠漂浮法检查土壤中人蛔虫卵。结果 2020年全国31个省（直辖市、自治区）的408个监测点人体土源性线虫总感染率为0.84%（3 485/415 672），其中感染率最高省份为海南（6.34%，199/3 141），其次为云南（5.80%，963/16 616）和四川（3.66%，592/16 168）；女性土源性线虫感染率为0.91%（1 944/213 591），高于男性的0.76%（1 541/202 081）（χ² = 27.20，P < 0.01）；≥ 60岁年龄组土源性线虫感染率最高，为1.26%（1 376/109 251），各年龄组间感染率差异有统计学意义（χ² = 382.28，P < 0.01）。监测点钩虫、蛔虫和鞭虫的感染率分别为0.51%（2 016/415 672）、0.19%（805/415 672）和0.16%（673/415 672）。其中钩虫、鞭虫仅检出轻度感染者，蛔虫轻度和中度感染者占比分别为99.25%（799/805）和0.75%（6/805）。28个省（直辖市、自治区）监测点共检测土壤样品2 604份，土壤中人蛔虫卵阳性率为3.07%（80/2 604），钩蚴阳性率为2.42%（63/2 604）。结论 2020年全国人体土源性线虫感染率总体上继续维持较低水平，但地域差异仍较大，高感染率地区依然存在。需要加强对60岁以上人群、妇女和儿童等重点人群的防治工作，开展健康教育等。

Objective To understand the situation of soil-transmitted nematode infection in China in 2020 and provide support for evaluating the development of surveillance on soil-transmitted nematodiasis in various provinces/municipalities/autonomous regions, and improving and perfecting the control strategies. Methods Surveillance was carried out in 408 national surveillance sites (counties) in 31 provinces (municipalities, autonomous regions) in China in 2020. With the county as unit, each site was divided into 5 areas geographically: east, west, south, north, and central part, followed by selecting one township (town), and therein one administrative village was selected from wherein, 200 permanent residents over the age of 3 were sampled. A total of 1 000 people were surveyed at each surveillance site. Fecal samples were collected from the sampled villagers, and examined by using the modified Kato-Katz thick smear method (two slide-reading for each sample) for infection of hookworm, Ascaris lumbricoides, Trichuris trichiura and Enterobius vermicularis, to calculate the infection rate and intensity, respectively. In addition, soil samples were collected from fields or vegetable gardens of each village in the survey site, and examined for hookworm larvae using 5% saline at 45 ℃, and for Ascaris eggs by saturated sodium nitrate flotation method. Results In 2020, the overall infection rate of soil-transmitted nematode in residents was 0.84% (3 485/415 672) in 408 surveillance sites of 31 provinces (municipalities/autonomous regions), with the highest found in Hainan (6.34%, 199/3 141), followed by Yunnan (5.80%, 963/16 616) and Sichuan (3.66%, 592/16 168); infection rate in females was 0.91% (1 944/213 591), which was higher than that of 0.76% in males (1 541/202 081) (χ² = 27.20, P < 0.01). The soil-transmitted nematode infection rate was the highest in the age group ≥ 60-years-old, which is 1.26% (1 376/109 251). The difference between each age group was statistically significant (χ² = 382.28, P < 0.01). The infection rates of hookworm, A. lumbricoides, T. trichiura were 0.51% (2 016/415 672), 0.19% (805/415 672) and 0.16% (673/415 672), respectively. Among them, hookworm and T. trichiura had only mildly infected cases. The proportions of mild and moderate A. lumbricoides infections were 99.25% (799/805) and 0.75% (6/805), respectively. In 2020, 2 604 soil samples were examined and found that the positive rate of Ascaris eggs and hookworms was 3.07% (80/2 604) and 2.42% (63/2 604), respectively. Conclusion In 2020, the infection rate of soil-transmitted nematode in China remains at a low level in general, but the regional differences are still significant, and the areas with high infection rates still exist. At the same time, it is necessary to strengthen the control measures for the key groups of people over age of 60, women and children, and carry out health education.