目的 了解2022年贵州省侗族人群芽囊原虫感染情况及影响因素。方法 于2022年采用横断面调查方法，对黔东南侗族地区黎平县芒岭村和地青村居民进行问卷调查，包括一般人口学信息和卫生习惯、有无胃肠道症状等，并采集粪样，提取粪样芽囊原虫基因组DNA，采用PCR扩增芽囊原虫小亚基核糖体RNA（SSU rRNA）基因片段序列。取阳性产物测序，测序结果在GenBank数据库中进行BLAST序列比对，确定芽囊原虫感染基因亚型。采用MEGA 7.0软件，用邻接法构建基于芽囊原虫SSU rRNA基因的系统进化树。采用卡方检验和Fisher确切概率法对纳入本研究居民芽囊原虫感染影响因素进行统计学分析。结果 共调查了329名居民，女性200人（60.8%）、男性129人（39.2%），平均年龄（47.95 ± 20.39）岁，侗族占98.5%（324/329）、汉族占1.2%（4/329）。PCR结果显示，有16份粪样扩增出芽囊原虫SSU rRNA基因片段，大小约1 100 bp。芽囊原虫总阳性率为4.9%（16/329）。其中男性阳性率为3.1%（4/129），女性阳性率为6.0%（12/200），二者差异无统计学意义（χ² = 1.425，P > 0.05）。> 69岁年龄组阳性率较高，为8.1%（3/37），不同年龄组间阳性率差异无统计学意义（χ² = 3.927，P > 0.05）。芽囊原虫阳性者职业均为农民，阳性率为6.1%（16/261），不同职业阳性率差异无统计学意义（χ² = 3.865，P > 0.05）。家庭人口数为6人及以上居民阳性率最高，为12.7%（7/55），不同家庭人口数阳性率差异有统计学意义（Fisher = 13.957，P < 0.01）。测序结果显示，芒岭村和地青村居民感染的芽囊原虫基因亚型有ST2、ST3、ST6、ST10等4种，其中ST6型最多（8/16），其次为ST3型（4/16）。BLAST比对分析结果显示，16份芽囊原虫阳性序列与参照序列的序列相似性均为90%以上。系统进化树结果显示，各基因亚型与其参照序列聚为一支，亲缘性较近。单因素分析结果显示，饮用水来源、家庭人口数、每日排便次数和大便性状对芽囊原虫感染的差异有统计学意义（χ² = 8.778、9.552、7.384、15.680，均P < 0.05）。多因素分析结果表明，饮用非开水[OR = 18.347，95% CI：（3.754，89.673）]是农村居民感染芽囊原虫的危险因素。结论 贵州省黔东南地区侗族居民的芽囊原虫总阳性率较高，主要基因亚型为ST6。饮用非开水是农村居民感染芽囊原虫的主要危险因素。

Objective To investigate the prevalence and influence factors of Blastocystis in the Dong ethnic group in Guizhou Province in 2022. Methods A cross-sectional survey was conducted through questionnaire investigation in the residents of Mangling Village and Diqing Village in Liping County, Dong ethnic group region, southeast Guizhou Province in 2022. The survey collected general demographic information, hygienic habits, evidence of gastrointestinal symtoms. In addition, fecal samples were collected to extract Blastocystis DNA from which the SSU rRNA gene fragment was amplified by PCR. The positive ampicon was sequenced, and the results were aligned by BLAST in the GenBank database to determine the subgenotype of Blastocystis. The MEGA7.0 software was used to construct phylogenetic tree based on the Blastocystis SSU rRNA gene sequence by neighbor-joining method. Chi-square test and Fisher exact probability method were used to analyze the influencing factors of Blastocystis infection in the residents included in this study. Results A total of 329 village residents were surveyed, including 200 females (60.8%) and 129 males (39.2%), with an average age of 47.95 ± 20.39 years, of which 98.5% (324/329) were of Dong ethnic group, and 1.2% (4/329) were of Han ethnic group. PCR results showed that 16 fecal samples amplified Blastocystis SSU rRNA fragments with a size of about 1 100 bp. The overall Blastocystis infection rate was 4.9% (16/329). There was no significant difference in the infection rates in males (3.1%, 3/129) and females (6.0%, 12/200) (χ² = 1.425, P > 0.05). The infection rate was higher in the age group over 69 years old, 8.1% (3/37), and there was no significant difference in the infection rate among different age groups (χ² = 3.865, P > 0.05). The Blastocystis infected individuals were all farmers, and the infection rate was 6.1% (16/261), and there was no significant difference in the infection rate between different occupations (χ² = 3.157, P > 0.05). The infection rate was the highest in households with 6 or more people (12.7%, 7/55), and the difference in infection rate between different household sizes was statistically significant (Fisher = 13.957, P < 0.01). There were 4 genotypes (ST2, ST3, ST6, ST10) infecting the residents of Mangling Village and Diqing Village. Among them, sub-genotype 6 is the most common, accounting for 50.0% (8/16), followed by sub-genotype 3, accounting for 25.0% (4/16). BLAST comparison analysis showed that the similarity between the positive sequences of 16 Blastocystis and the reference sequences was more than 90%. The phylogenetic tree results also showed that each gene subtype clustered with its reference sequence, and the parentage was high. Univariate analysis showed that drinking water source, family size, daily stool frequency and stool traits have significant differences in Blastocystis infection (χ² = 8.778, 9.552, 7.384, 15.680; P < 0.05). The results of multivariate analysis showed that drinking unboiled water [OR = 18.347, 95% CI: (3.754, 89.673)] was a risk factor for Blastocystis infection in rural residents. Conclusion The overall infection rate of Blastocystis among Dong ethnic residents in southeast Guizhou Province is comparatively, with the main subgenotype ST6. Drinking unboiled water is the main risk factor for infection with Blastocystis in rural residents.