Meta-analysis of camel trypanosomosis in Ethiopia

Abstract

Camel is animal of great economic contribution to pastoralists and endowed with prestigious social value. Camels play significant role in the livelihood of the pastoralists and agro-pastoralists living in the fragile environments. The main purpose of this meta-analysis was to compute the pooled prevalence estimate of camel trypanosomosis based on the available studies. Published articles on camel trypanosomosis were searched in PubMed, Google scholar and African journals online (AJOL). The key electronic search words were: camel, trypanosomosis, Trypanosoma evansi , and surra.The preliminary screening of the articles was based on the title and abstract. The analysis was based on 11 cross-sectional study reports, which were done between the year 2008 and 2016, and in four administrative regions of Ethiopia. The pooled prevalence estimate in a random effects meta-analysis was 9.2% (95% CI 7.1- 11.8). Enormous heterogeneity were noted among the studies (I 2 = 94.4%). In subgroup and multivariable meta-regression analyses however, only two predictors namely sample size and diagnostic techniques were found to have significant effect ( p <0.05). Accordingly, the aforementioned predictor sex explained 51.8% of the explainable proportion of the heterogeneity noted between studies. In this regard, serological and molecular based reports were noted to have higher prevalence compared to wet smear and buffy coat. On the other hand, studies with smaller sample size had less prevalence compared to large sample size. Trypanosoma evansi is the only species identified and reported in all the study reports. This analysis results underscores the need for further study that involve more sensitive diagnostic techniques to reveal the precise magnitude of the disease, and to identify the vectors in all camel rearing areas of the country. Keywords: Camel; Ethiopia; Hetrogenity; Meta-analysis; Pooled prevalence;  Trypanosoma evansi