Epidemiology of bovine schistosomiasis and associated risk factors in Ethiopia: A systematic review with meta-analysis of published articles, 2008–2018

Schistosomiasis is a tropical and subtropical parasitic infection that affects both animals and humans. It’s caused by the Schistosoma genus and spreads via snails as an intermediate host. Schistosoma bovis is widely spread in Ethiopia’s Northern, Eastern, Southwestern, and Central regions. It is an economically significant cattle disease with global health implications. Despite numerous prevalence studies of bovine schistosomiasis in different regions of the country, no systematic review and meta-analysis of the disease has ever been undertaken. As a reason, the purpose of this research was to provide information that can be used in the planning and design of Schistosoma interventions in Ethiopia, as the world aims to eliminate schistosomiasis as a public health problem by 2030. The PRISMA statement guidline was used to check the eligiblities of the included studies. Electronic bibliographic databases such as PubMed, Google Scholar, HINARI, and Web of science, reference lists from retriv articles, books, libraries, megazins and existing reviews manaually were employed for literature searches. The pooled prevalence of bovine schistosomiasis and heterogeneity among included studies was estimated by employing random effect models and the inverse variance index, respectively. To investigate the source of heterogeneity across and within studies, subgroup analysis was undertaken based on sample size, study years, and study regions. To assess publication bias and small study effects, funnel plotsand Egger’s regression test were used. The pooled prevalence was calculated with a 95% confidence interval using STATA 17 software. To identify the various risk variables related to the prevalence of bovine schistosomiasis, a pooled odd ratio was used Based on the inclusion criteria, a total of 20 studies were discovered and included in the meta-analysis. The prevalence of bovine schistosomiasis was found to range from 22 to 45.7%. In this meta-analysis, the estimated pooled prevalence of bovine schistosomiasis was 24% (95% CI: 17% to 31%). Substantial heterogeneity was observed across the included studies (I(2) = 88.04%; p< 0.001). The results of the funnel plot and Egger’stests revealed no substantial publication bias (Egger’s test; p = 0.509). The pooled odds ratio indicated that poor body condition was positively associated with the infection rate of bovine schistosomiasis (OR: 4.915, 95% CI: 2.675 to 9.030; p<0.001), with poor body conditioned animals having 4.915 times higher likelihood to schistosomiasis infection. This review found that the overall prevalence of bovine schistosomiasis was high and the body condition of animals was identified risk factor for Schistosoma infection among the studied factors. Therefore, this review found that the occurrence of bovine schistosomiasis was strongly associated with the state of body condition of animals. Further, sufficient numbers of prospective studies should be conducted to address other potential risk factors of bovine schistosomiasis in Ethiopia.