An African perspective on the genetic diversity of Toxoplasma gondii: A systematic review

The study of Toxoplasma gondii genotypes is beneficial for detecting strains linked to increased disease severity and uncovering the processes involved in the transmission and distribution of this zoonotic parasite. A systematic review of literature was conducted to investigate the present status of T. gondii genetic diversity in African countries and among host species on the continent. Data from the results in the included studies were sorted, reviewed and descriptively analysed using tables, graphs and maps. Results indicate that there is a relative amount of genetic diversity with a clear difference in the population structure between geographical regions and the propensity for unique and regional genotypes to be predominant in tropical rainforest biomes, near the equator. From a clinical perspective, connections between specific T. gondii genotypes and disease manifestations were found. Theories are outlined on the dissemination of African T. gondii genotypes to other continents. The overrepresentation of samples from one geographical area and dissimilar genotyping methodologies creates challenges when concluding on the genetic diversity of T. gondii in Africa. The need for uniform genotyping methods with a continent-wide sampling of an extensive host range involving humans, domestic animals and wildlife is emphasized.