Department of Medical Parasitology and Mycology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization, Mashhad, Iran.
Int Health. 2022 Jan 19;14(1):5-17. doi: 10.1093/inthealth/ihab026.
Application of chemotherapeutics in cancer patients may provide an immunosuppressive milieu, favourable for parasitic infections. Giardia duodenalis is an important zoonotic intestinal parasite responsible for diarrhoea in humans worldwide.
The present systematic review and meta-analysis was conducted to estimate the prevalence of G. duodenalis and respective odds ratios (ORs) in cancer patients around the globe. Four online databases-PubMed, Scopus, Web of Science and Google Scholar-were carefully explored for relevant literature without time limitation until 28 November 2020. Meta-analysis was done based on a random effects model to pool the estimations and define 95% confidence intervals (CIs).
The overall weighted prevalence of G. duodenalis infection in cancer patients was calculated to be 6.9% (95% CI 0.5 to 9.3) globally, based on data from 32 studies. Although not statistically significant, eight case-control studies revealed that cancer patients were 1.24 times (95% CI 0.66 to 2.31; p=0.501) more exposed to G. duodenalis infection than healthy controls. Moreover, the prevalence of infection was not significantly associated with quantitative variables, including publication year (regression coefficient -0.0135, p=0.578), sample size (regression coefficient -0.0007, p=0.074) and human development index (regression coefficient -1.6263, p=0.419). Also, subgroup analysis of the pooled G. duodenalis infection was performed for publication year, World Health Organization regions, countries, continents, cancer types and country income.
Altogether, the epidemiology of G. duodenalis infection and its associated risk factors in immunocompromised individuals, especially cancer patients, is still open to question and deserves comprehensive investigations.
癌症患者应用化疗药物可能会产生免疫抑制微环境，有利于寄生虫感染。十二指肠贾第鞭毛虫是一种重要的动物源肠道寄生虫，可导致全球人类腹泻。
本系统评价和荟萃分析旨在评估全球癌症患者中十二指肠贾第鞭毛虫的流行率和相应的比值比（OR）。我们在没有时间限制的情况下，仔细检索了 PubMed、Scopus、Web of Science 和 Google Scholar 这四个在线数据库，以获取相关文献，检索截止日期为 2020 年 11 月 28 日。采用随机效应模型进行荟萃分析，以汇总估计值并定义 95%置信区间（CI）。
根据 32 项研究的数据，全球范围内癌症患者十二指肠贾第鞭毛虫感染的总加权流行率为 6.9%（95%CI 0.5 至 9.3）。虽然没有统计学意义，但 8 项病例对照研究表明，癌症患者感染十二指肠贾第鞭毛虫的风险比健康对照组高 1.24 倍（95%CI 0.66 至 2.31；p=0.501）。此外，感染的流行率与定量变量（包括发表年份、样本量和人类发展指数）无显著相关性（回归系数分别为-0.0135、-0.0007 和-1.6263，p 值分别为 0.578、0.074 和 0.419）。还按发表年份、世界卫生组织区域、国家、大洲、癌症类型和国家收入进行了荟萃分析。
总的来说，免疫功能低下者（尤其是癌症患者）感染十二指肠贾第鞭毛虫的流行病学及其相关危险因素仍存在疑问，需要全面调查。
