Department of Parasitology, Harbin Medical University, Harbin, China.
Department of Helminth, Yunnan Institute of Parasitic Diseases, Puer, China.
PLoS Negl Trop Dis. 2019 May 23;13(5):e0007356. doi: 10.1371/journal.pntd.0007356. eCollection 2019 May.
Enterocytozoon bieneusi is the most common microsporidian species causing diarrhea and other intestinal disorders in humans and animals. Like other infectious diseases, microsporidiosis usually disproportionately affects poor populations. In China, some ethnic minority areas remain poor. Currently, no information of E. bieneusi infection is available in minority populations. The present aims were to understand occurrence and genetic characterizations of E. bieneusi in ethnic minority groups from a poverty-stricken ethnic township in Yunnan Province, and to assess risk factors for E. bieneusi infection.
METHODOLOGY/PRINCIPAL FINDINGS: 289 fecal specimens were collected from Yao people (one specimen each) with and without diarrhea, in Yunnan Province. E. bieneusi was identified and genotyped by PCR and sequence analysis of the ITS region of the rRNA gene. An average prevalence of 8.30% (24/289) was observed and four genotypes were identified-genotype Peru6 (n = 21) and three novel genotypes (one each). Genotype Peru6 was detected in two family members in each of three families. In a phylogenetic analysis, all of four genotypes fell into group 1 with zoonotic potential. The people owning individual pit toilets had a statistically higher prevalence of E. bieneusi (16.67%, 12/72) than those using public pit toilets (6.06%, 12/198).
CONCLUSIONS/SIGNIFICANCE: This is the first report on occurrence and genetic characteristics of E. bieneusi in ethnic minority groups in China. Genotype Peru6 was found in humans in China for the first time and showed dominance in Yao people. The same genotype was found in some family members and all the genotypes fell into group 1, suggesting the possibility of anthroponotic and zoonotic transmissions. The majority (83.33%, 20/24) of E. bieneusi positive individuals did not present diarrhea. In any case, it is important to recognize their existence and the importance that asymptomatic individuals to E. bieneusi may have from an epidemiological point of view, as transmitters of this pathogen. The analysis of risk factors provides scientific evidence for the development of effective strategies for prevention and control of E. bieneusi infection.
肠微孢子虫是导致人类和动物腹泻及其他肠道疾病的最常见微孢子虫种类。与其他传染病一样，微孢子虫病通常不成比例地影响贫困人群。在中国，一些少数民族地区仍然贫困。目前，少数民族群体中没有关于肠微孢子虫感染的信息。本研究旨在了解云南省一个贫困民族乡镇少数民族群体中肠微孢子虫的发生情况和遗传特征，并评估肠微孢子虫感染的危险因素。
方法/主要发现：从云南省采集了 289 份有和无腹泻的姚人粪便标本（每人一份）。通过 PCR 和 rRNA 基因 ITS 区序列分析鉴定和基因分型肠微孢子虫。观察到平均患病率为 8.30%（24/289），鉴定出 4 种基因型-秘鲁 6 基因型（n=21）和 3 种新型基因型（各 1 种）。在 3 个家庭中，每个家庭的 2 名家庭成员中都检测到秘鲁 6 基因型。在系统发育分析中，所有 4 种基因型均属于具有人畜共患潜力的第 1 组。使用个体坑式厕所的人群感染肠微孢子虫的患病率（16.67%，12/72）明显高于使用公共坑式厕所的人群（6.06%，12/198）。
结论/意义：这是中国少数民族人群中肠微孢子虫发生和遗传特征的首次报告。在中国，首次在人类中发现秘鲁 6 基因型，且在姚人群体中占优势。在一些家庭成员中发现了相同的基因型，所有基因型都属于第 1 组，提示可能存在人际传播和人畜共患传播。大多数（83.33%，20/24）肠微孢子虫阳性个体未出现腹泻。在任何情况下，从流行病学角度来看，认识到无症状个体对肠微孢子虫的存在及其作为该病原体传播者的重要性是很重要的。危险因素分析为制定有效的肠微孢子虫感染防控策略提供了科学依据。
