Prevalence of Cryptosporidium Infection in Sheep and Goat Flocks in China During 2010-2019: A Systematic Review and Meta-Analysis

Cryptosporidiosis is an extensively contagious zoonotic waterborne disease caused by the genus Cryptosporidium and poses to be a danger to public health. Sheep and goats are an intermediate host of Cryptosporidium. Consequently, a first systematic review and meta-analysis are performed to assess the burden of the infection relative to the Cryptosporidium in sheep and goat flocks in China. Five databases were searched for relevant literature in accordance with the inclusion criteria until January 30, 2020. At last, a total of 33 qualified documents were included. We calculate the overall prevalence of Cryptosporidium (4.9%) in sheep and goats in China with the random-effects model. The prevalence after 2014 (4.6%) was higher than that before or in 2014 (2.8%). The pooled prevalence of Cryptosporidium in sheep and goats from Northern China (12.3%) was significantly higher (p < 0.05) than other regions. The infection rate of modified acid-fast staining (14.3%) was the highest among the detection methods. In age subgroups, the prevalence of Cryptosporidium in sheep and goats in 3 months or before was the highest (20.8%). Goats had a higher infection rate (5.9%) in species. The prevalence of large-scale farms (2.8%) was lower than free-ranging farms (4.4%). The medium quality level (6.4%) was the highest. Besides, geographical factors (such as latitude, longitude, height, precipitation, humidity, mean temperature, etc.) were further analyzed as potential risk factors of Cryptosporidium in sheep and goats. This meta-analysis indicates that the Cryptosporidium infection of Chinese sheep and goat flocks is general. Thus, it is necessary to further monitor the prevalence of Cryptosporidium, and the reasonable preventive strategy should be formulated on the basis of the geographical factors of different regions and the differences in sheep and goats' growth stages to reduce the prevalence of Cryptosporidium in sheep and goats.