The Roles of Climatic and Biological Factors on the Prevalence of Fascioliasis: A Case Study of Fasciola gigantica

Fascioliasis, caused by Fasciola hepatica and Fasciola gigantica, is a climate-sensitive zoonotic disease with the widest global distribution across all continents. As such, it poses a significant threat to the health and well-being of both animals and humans. Beyond its health effects, fascioliasis causes substantial economic losses amounting to millions of dollars in different parts of the world. The life cycle of the parasite is critically dependent on optimal moisture and thermal conditions. However, other biological factors also contribute significantly to the prevalence of the parasite in endemic areas. Based on this background, this paper examines the roles of both climatic and biological determinants in the prevalence of Fasciola gigantica. It was found that vegetative cover, temperature, and moisture at optimal levels affect not only the parasite‟s developmental stages but also its intermediate host snail (R. natalensis). Furthermore, other biological factors that greatly influence parasite prevalence include the age and sex of the definitive host, as well as livestock management practices. It is therefore essential to understand the significance and relevance of these factors in order to build effective capacity to contain the spread of this pathogen, which is taking a heavy toll on animal and human productivity.