Abstract: Objective　To investigate the prevalence and influencing factors of Blastocystis hominis infection among children with diarrhea under five years of age in Guangzhou City. Methods　Children with diarrhea under 5 years of age admitted to Guangzhou Children’s hospital, Guangzhou Maternity and Child Healthcare Hospital and Guangzhou Women and Children’s Medical Center during the period between January 1 and December 31, 2020, were enrolled. Participants’ demographics, living environments and health status were collected using questionnaire surveys. Stool samples were collected from participants and nucleic acid was extracted. B. hominis infection was identified using PCR assay and sequence alignment, and the factors affecting B. hominis infection among children with diarrhea under 5 years of age were identified using univariate analysis and multivariate logistic regression analysis. Results　A total of 684 children with diarrhea under 5 years of age were enrolled, including 468 male children and 216 female children, with a mean age of (1.79 ± 1.12) years. The overall prevalence of B. hominis infection was 4.97% [34/684, 95% confidential interval (CI): (3.59%, 6.86%)] among participants, and there was no significant difference in the prevalence of B. hominis infection between children with chronic [7.52% (20/266), 95% CI: (4.92%, 11.33%)] and acute diarrhea [3.35% (14/418), 95% CI: (2.01%, 5.54%)] ([χ2] = 5.983, P = 0.014). Multivariate logistic regression analysis identified keeping pet [odds ratio (OR) = 6.298, 95% CI: (2.711, 14.633)], drinking non⁃tap water [OR = 4.522, 95% CI: (1.769, 11.561)], lactose intolerance [OR = 4.221, 95% CI: (1.043, 17.087)], antibiotic use [OR = 0.125, 95% CI: (0.017, 0.944)] and chronic diarrhea [OR = 2.172, 95% CI: (1.018, 4.637)] as factors affecting B. hominis infection among children with diarrhea under 5 years of age in Guangzhou City. Conclusions　B. hominis infections is detected in children with diarrhea under five years of age in Guangzhou City. Improving home environments and pet⁃keeping hygiene is recommended to reduce the likelihood of B. hominis infection among children.

Key words: Blastocystis hominis, Epidemiological characteristic, Influencing factor, Diarrhea, Children, Guangzhou City

摘要： 目的　了解广州市5岁以下腹泻儿童人芽囊原虫感染率及其影响因素。方法　以2020年1月1日至12月31日广州市儿童医院、广州市妇婴医院和广州市妇女儿童医疗中心收治的5岁以下腹泻患儿作为调查对象，通过问卷调查了解患儿基本情况、生活环境、健康状况等信息。采集腹泻患儿粪便样本，提取核酸，通过PCR检测、序列对比确定是否感染人芽囊原虫。采用单因素分析和多因素logistic回归分析对5岁以下腹泻儿童感染人芽囊原虫的影响因素进行分析。结果　共招募5岁以下腹泻儿童684例，其中男、女童分别为468例和216例，平均年龄为（1.79 ± 1.12）岁。腹泻儿童人芽囊原虫感染率为4.97% [34/684，95%置信区间（confidential interval, CI）：（3.59%，6.86%）]；慢性腹泻儿童感染率[7.52%（20/266），95% CI：（4.92%，11.33%）] 高于急性腹泻儿童 [3.35%（14/418），95% CI：（2.01%，5.54%）]，差异有统计学意义（[χ2] = 5.983，P = 0.014）。多因素logistic回归分析显示，饲养宠物 [比值比（OR）= 6.298，95% CI：(2.711，14.633）]、饮用非自来水[OR = 4.522, 95% CI：（1.769，11.561）]、乳糖不耐受 [OR = 4.221，95% CI：（1.043，17.087）]、使用抗生素 [OR = 0.125，95% CI：（0.017，0.944）] 和慢性腹泻 [OR = 2.172，95% CI：（1.018，4.637）] 是广州市5岁以下腹泻儿童人芽囊原虫感染的影响因素。结论　 广州市5岁以下腹泻儿童中存在人芽囊原虫感染，建议改善家庭环境及宠物卫生状况，以降低儿童感染人芽囊原虫等病原体的机会。

关键词: 人芽囊原虫, 流行病学特征, 影响因素, 腹泻, 儿童, 广州市