Epidemiology of Cysticercus tenuicollis in Sheep and Goats in the Tropics: A Systematic Review.

Sheep and goat influence the socioeconomic sustainability of rural communities in tropical countries, but parasitic diseases and Cysticercus tenuicollis in particular are responsible for their low productivity. The occurrence of Cysticercus tenuicollis in most affected regions of the world has been associated to the presence of stray dogs in the grazing area, which play vital roles in the life cycle of the parasite and poor disposal of contaminated and seized offal, organs, and carcasses. The aim of this paper is to systematically review the epidemiology of Cysticercus tenuicollis infection in sheep and goats in the tropics between 2010 and 2022 through the analysis of published qualitative and quantitative data on prevalence, risk factors, organ distribution, and interventions. The review showed that goats are more susceptible to Cysticercus tenuicollis than sheep in the tropics, and the prevalence rates based on meat inspection range from 0.45% to 56.8% in sheep and 4.83% to 72.38% in goats. More adult (2.9% to 83.17%) and female (0.96% to 71.42%) were infected than young (2.7% to 61.79%) and male (2.3% to 72.53%) animals. Higher infection rates were reported among animals in highland (7.99% to 73.61%) compared to animals in lowlands (4.70% to 69.69%). Overall, Cysticercus tenuicollis were observed on the abdominal visceral organs but predominantly on the omentum and liver, and affected animals were significantly higher during wet seasons. The review highlights the implementation of the One Health approach to improve understanding of the epidemiology, roles of different hosts, and environmental health in relation to the prevention and control of Cysticercus tenuicollis in the tropics.