The significance of opportunistic infections in immunocompromised patients and the enigmatic pathogenicity of Blastocystis directed us to conduct the first global systematic review and meta-analysis on Blastocystis prevalence, odds ratios (ORs), and subtypes distribution in various immunocompromised patients (HIV/AIDS, cancer and hemodialysis patients, as well as transplant recipients). The systematic searching procedure was done in Web of Science, PubMed, Scopus, and Google Scholar databases for relevant published literature until November 11, 2020. Random-effects model was utilized to calculate the weighted estimates and 95% confidence intervals (95% CIs). The computed pooled prevalence of Blastocystis inferred from 118 papers (128 datasets) on immunocompromised patients was 10.3% (95% CI: 8.7–12.2%), with 16.1% (95% CI: 11.3–22.2%), 12.5% (95% CI: 8.5–18%), 8.4% (95 % CI: 6.6–10.6%), and 6% (95% CI: 2.6–13.3%) for hemodialysis patients, cancer patients, HIV/AIDS patients, and transplant recipients, respectively. Based on 50 case-control studies (54 datasets), the highest ORs were associated with cancer [2.81 (95% CI: 1.24–6.38, P = 0.013)] and hemodialysis patients [2.78 (95% CI: 1.19–6.48, P = 0.018)]. The most frequent subtype being found in immunocompromised patients was ST3 [41.7% (95% CI: 31.4–52.7%)], followed by ST1 [31.7% (95% CI: 23.2–41.8%)] and ST2 [23.1% (95% CI: 14.8–34.1%)]. Also, the weighted frequency of Blastocystis in various subgroups (publication year, WHO regions, geographical distribution, continents, and country income) was analyzed separately. In total, the results of the present meta-analysis highlighted that one’s immunodeficiency status is probably associated with an increased Blastocystis infection, underpinning strict preventive measures to be taken.

免疫功能低下患者机会性感染的重要性和芽囊原虫神秘的致病性促使我们对各种免疫功能低下患者（HIV/AIDS、癌症和血液透析患者，以及移植受者）。在 Web of Science、PubMed、Scopus 和 Google Scholar 数据库中对相关已发表文献进行了系统搜索，直至 2020 年 11 月 11 日。使用随机效应模型计算加权估计值和 95% 置信区间 (95% CI) . 囊原虫的计算汇总流行率从 118 篇关于免疫功能低下患者的论文（128 个数据集）中推断出 10.3%（95% CI：8.7-12.2%）、16.1%（95% CI：11.3-22.2%）、12.5%（95% CI：8.5-18%） )、8.4% (95% CI: 6.6–10.6%) 和 6% (95% CI: 2.6–13.3%) 分别用于血液透析患者、癌症患者、HIV/AIDS 患者和移植受者。基于 50 项病例对照研究（54 个数据集），最高 OR 与癌症 [2.81 (95% CI: 1.24–6.38, P = 0.013)] 和血液透析患者 [2.78 (95% CI: 1.19–6.48, P = 0.018)]。在免疫功能低下患者中发现的最常见亚型是 ST3 [41.7% (95% CI: 31.4–52.7%)]，其次是 ST1 [31.7% (95% CI: 23.2–41.8%)] 和 ST2 [23.1% (95 % 置信区间：14.8–34.1%)]。此外，囊胚的加权频率在不同的子组（出版年份、WHO 区域、地理分布、大陆和国家收入）中分别进行了分析。总的来说，本荟萃分析的结果强调，一个人的免疫缺陷状态可能与芽囊原虫感染增加有关，支持采取严格的预防措施。