The prevalence of microsporidia in China : A systematic review and meta-analysis

Microsporidia are a diverse parasite phylum infecting host from all major taxa in all global biomes. This research was conducted to conclude the prevalence of microsporidia in China. All published articles up to February 16, 2018 were considered, including descriptive, cross-sectional, case-control and epidemiology studies. A total of 1052 articles were separated after literature search. After a strict selection according to our criteria, 82 articles were included in qualitative synthesis and ultimately 52 studies were included in quantitative synthesis. Three species of microsporidia were confirmed to exist in China, including Enterocytozoon bieneusi (E. bieneusi), Nosema and Encephalitozoon cuniculi (E. cuniculi). The highest overall estimated prevalence of E. bieneusi in humans was 8.1%, which was observed in acquired immunodeficiency syndrome patients (AIDS). Moreover, the prevalence of E. bieneusi in animals including the cattle, dogs, pigs, deer, sheep and goats were analyszed in this study. The overall estimated prevalence of E. bieneusi acquired by using the random effects model in meta-analysis in cattle, dogs, pigs, sheep and goats and deer was 20.0% (95% confidence intervals: 0.133-0.266, I² = 98.031%, p < 0.0001), 7.8% (95% CI: 0.050-0.106, I² = 60.822%, p = 0.0537), 45.1% (95% CI: 0.227-0.674, I² = 98.183%, p < 0.0001), 28.1% (95% CI: 0.146-0.415, I² = 98.716%, p < 0.0001) and 19.3% (95% CI: 0.084-0.303, I² = 96.995%, p < 0.0001) respectively. The overall detection rate of E. bieneusi in water acquired by using the random effects model in meta-analysis was 64.5% (95% CI: 0.433-0.857, I² = 98.486%, p < 0.0001). Currently, 221 genotypes of E. bieneusi, 1 genotype of E. cuniculi and 6 Nosema were detected in China. The most prevalent genotype of E. bieneusi was genotype D, followed by BEB6 and EbpC.