为了解上海市人体常见致腹泻性寄生原虫的感染情况,根据市、郊结合的原则,2015—2019年选择上海市长宁、虹口、闵行、嘉定和浦东新区等5个区各1~2家综合性医院,采集监测点医院就诊的腹泻患者（24 h内大便次数3次以上,粪便性状改变者）粪样,分别采用生理盐水涂片法、碘液染色法和抗酸染色法,以及粪抗原免疫层析法检测溶组织内阿米巴原虫、蓝氏贾第鞭毛虫、隐孢子虫,分析原虫感染情况。结果显示,2015—2019年共采集并检测腹泻患者粪样6 984份,病原学检测检出寄生原虫阳性9份,总阳性率为0.13%（9/6 984）。其中检出溶组织内阿米巴原虫、蓝氏贾第鞭毛虫和隐孢子虫阳性分别为4、2和3例。各年度阳性率分别为0.08%（1/1 207）、0.40%（5/1 254）、0.13%（2/1 506）、0（0/1 509）和0.07%（1/1 508）。6 984名腹泻患者中,以30~40岁年龄组较多,检出4例;男性和女性分别检出4例和5例;长宁区、虹口区、闵行区、嘉定区分别检出2、2、2、3例,浦东新区未检出阳性者。采用原虫粪抗原快速检测试剂检出阳性31份,总阳性率为0.44%（31/6 984）,与病原学检测方法检出的总阳性率差异有统计学意义（χ² = 12.13,P < 0.01）。提示上海市寄生原虫阳性率保持在较低水平,处于低感染或零星散在感染状态。应继续开展健康宣教,加强连续有效的监测;并采用病原、免疫和分子生物学联合检测方法提高检出率。

To understand common infection status of diarrhea-causing parasitic protozoa in residents of Shanghai Municipality, a survey was carried out through selecting 1-2 general hospitals from five districts, including Changning, Hongkou, Minhang, Jiading and Pudong New District, as surveillance sites in 2015—2019. Fecal samples were collected from diarrhea patients (defecation for more than three times within 24 h, with abnormal feces appearance), who visited the surveillance site hospital, based on the principle of sampling from both urban and the suburb districts. Using the methods of direct smear with saline, iodine staining, acid-fast staining and coproantigen immuno-chromatography, the fecal samples were examined for Entamoeba histolytica, Giardia lamblia and Cryptosporidium, and analyzing the infection status. The results showed that a total of 6 984 fecal samples were collected from diarrhea patients and examined etiologically, of them 9 were found positive, with an overall infection rate of 0.13% (9/6 984) in 2015—2019. Among the positives, 4 were infected with E. histolytica, 2 were G. lamblia and 3 were Cryptosporidium. The positive rates in each year were 0.08% (1/1 207), 0.40% (5/1 254), 0.13% (2/1 506), 0 (0/1 509) and 0.07% (1/1 508), respectively. Among the 6 984 patients with diarrhea, the age group of 30-40 years (1 370) had 4 cases of protozoa infection; of 3 345 males, 4 were found protozoa positive, while from 3 639 females, 5 were positive; there were 2, 2, 2, 3 positive cases were detected in districts of Changning, Hongkou, Minhang, and Jiading, whereas no positive cases were detected in Pudong New District. Protozoan coproantigen fast test strip detected 31 positives, with an overall positive rate of 0.44% (31/6 984), which was significantly different from the findings by pathogen examination (χ² = 12.13,P < 0.01). The positive rate of parasitic protozoa was found at a considerably low level, maintaining at low prevalence and in scattering distribution in Shanghai. Therefore, it is urged to carry on health education, and to strengthen continuous and effective surveillance; applying combined approaches of etiology, immunology, and molecular biology for improving the detection rate.