目的 了解2016—2020年青海省土源性线虫国家级监测点人群，为制定土源性线虫病防治策略提供依据。 方法 2016—2020年在全省29个县（市、区）设立国家级监测点，每年固定监测点2个，流动监测点5~6个。各监测点按地理位置划分为东、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，整群抽取3周岁以上常住居民200人为调查对象。采集调查对象粪样，采用改良加藤厚涂片法（Kato-Katz法，一粪二检）检测土源性线虫虫卵；对3~9岁儿童同时采用透明胶纸肛拭法检测蛲虫卵。计算人群土源性线虫感染率、感染度，分析感染人群的性别、年龄、民族、职业、地区的分布情况。组间感染率的比较采用卡方检验。 结果 2016—2020年共调查37 724人，土源性线虫总感染率为0.86%（323/37 724）。感染虫种以蛔虫为主，感染率为0.85%（322/37 724），占总感染人数的99.69%（322/323），轻度感染占87.89%（283/322），中度感染占12.11%（39/322）。3~9岁儿童蛲虫感染率为0.02%（1/4 069）。男、女性土源性线虫感染率分别为0.80%（148/18 550）、0.91%（175/19 174），二者感染率差异无统计学意义（χ² = 1.611，P > 0.05）；3~10岁人群土源性线虫感染率最高，为1.42%（90/6 351），不同年龄组人群感染率差异有统计学意义（χ² = 43.516，P < 0.01）；汉族人群土源性线虫感染率最高，为1.66%（276/16 622），不同民族人群感染率差异有统计学意义（χ² = 242.302，P < 0.01）；民工土源性线虫感染率最高，为2.82%（5/177），不同职业人群感染率差异有统计学意义(χ² = 178.710，P < 0.01)。2016—2020年，固定监测点中，平安区的土源性线虫感染率分别为1.21%（24/1 086）、3.37%（39/1 157）、1.70%（17/1 000）、1.19%（13/1 091）和0.80%（8/1 003），不同年度之间感染率差异有统计学意义（χ² = 25.239，P < 0.01）；互助县的感染率分别为1.81%（18/994）、2.47%（24/971）、2.28%（23/1 007）、3.01%（30/998）和2.37%（24/1 012），不同年度之间感染率差异无统计学意义（χ² = 3.132，P > 0.05）。2016—2020年，27个流动监测点共检出土源性线虫感染者103例，99例（占96.12%）分布于祁连山地-河湟谷地；柴达木盆地未检出感染者，不同地区感染率差异有统计学意义（χ² = 378.856，P < 0.01）。 结论 青海省监测人群的土源性线虫感染较低，以蛔虫感染为主；3~10岁儿童、民工为今后防控的重点人群。

Objective To understand the infection status of soil-transmitted helminth (STH) at national surveillance sites in Qinghai Province from 2016 to 2020 to provide a scientific basis for formulating prevention and control strategies. Methods National surveillance sites were set up in 29 counties (cities, districts) in Qinghai Province during 2016—2020, comprising 2 fixed surveillance sites and 5-6 mobile sites every year. Each surveillance site was divided into 5 areas as geographically at east, west, south, north and centre. In each area, one administrative village was randomly selected from one township for cluster sampling of no less than 200 permanent residents over 3 years old. Fecal samples of residents were collected and examined for STH eggs with the modified Kato-Katz thick smear method (two slide-reading for each sample). At the same time, children aged 3-9 years were examined for Enterobius vermicularis eggs using cellophane anal swab method. The infection rates and infection intensity were calculated. The distribution of gender, age, ethnic group, occupation and region of the infected population were analyzed. The Chi-square test was used to compare the infection rate between different groups. Results A total of 37 724 residents were examined during 2016—2020. The overall infection rate of STH was 0.86% (323/37 724), with Ascaris lumbricoides is the main pspecies, accounting for 99.69% (322/323) of the total infected. The infection rate of A. lumbricoides was 0.85% (322/37 724), including 87.89% (283/322) mild infection and 12.11% (39/322) moderate infection. The infection rate of En. vermicularis was 0.02% (1/4 069) in children aged 3-9 years. The infection rates of STH in males and females were 0.80% (148/18 550) and 0.91% (175/19 174), respectively, with no statistically significant difference(χ² = 1.611, P > 0.05). The 3-10 years old group had the highest infection rate of STH (1.42%, 90/6 351), with statistically significant in different age groups (χ² = 43.516, P < 0.01). The Han ethnic group had the highest infection rate of STH (1.66%, 276/16 622), with statistically significant differences in different ethnic groups (χ² = 242.302, P < 0.01). Migrant workers had the highest infection rate of 2.82% (5/177), with statistically significant differences among different occupations (χ² = 178.710, P < 0.01). From 2016 to 2020, the infection rate of STH in Pin’an County was 1.21% (24/1 086), 3.37% (39/1 157), 1.70% (17/1 000), 1.19% (13/1 091) and 0.89% (9/1 003), the differences between years were statistically significant (χ² = 25.239, P < 0.01). The infection rate of STH in Huzhu County was 1.81% (18/994), 2.47% (24/971), 2.28% (23/1 007), 3.01%(30/998) and 2.37% (24/1 012), showing a fluctuated changes, with no significant difference among them (χ² = 3.132, P > 0.05). From 2016 to 2020, 103 residents with STH infection were found in 27 mobile surveillance sites, of which 99 infected residents (96.12%) were found in the Qilian Mountains and Hehuang Valley. No infected resident was found in the Caidamu Basin. The difference in infection rates among different regions was statistically significant (χ² = 378.856, P < 0.01). Conclusion The infection rate of STH was considerably low in surveillance sites in Qinghai Province, mainly with A. lumbricoides infection. Children aged 3-10 years old and migrant workers are the key groups for prevention and control in the future.