Tick Diversity, Emerging Tick-Borne Pathogens, and Public Health Implications Across Africa: A Systematic Review

This systematic review analyzed tick and pathogen diversity across Africa,aiming to provide a continental overview of the distribution patterns and zoonotic potential oftick-borne pathogens (TBPs). Understanding these dynamics is essential for guiding surveillanceand control efforts across regions with diverse ecological and epidemiological contexts.

The synthesis of findings was qualitative, as a formal meta-analysis and quantitativeassessment of study quality were not feasible due to the varied methodologies and outcomemeasures of the included studies. Data were systematically analyzed in R software, focusing ondescriptive statistics such as counts of tick species and the distribution of associated pathogens.To visualize these relationships, figures and graphs were generated using the ggplot2 package inR, and summary tables were created with gtsummary. Furthermore, Sankey diagrams weredeveloped via sankeymatic.com to effectively illustrate the flow and associations between tickspecies and the pathogens they harbor.

West Africa exhibited the greatest number oftick species, followed by East and Central Africa. Five major tick genera were identified, withRhipicephalus being the most prevalent. A wide range of pathogens including rickettsial, viral,and protozoan agents were detected, 19 of which are known to infect humans. Crimean-Congohemorrhagic fever virus and Rickettsia africae were highlighted as particularly concerning dueto their wide distribution and zoonotic potential. Moreover, the presence of livestock pathogens such as Babesia bigemina and Ehrlichia ruminantium in both wild and domestic animals suggest a potential risk of spillover to humans.

Despite ongoing efforts to combat tick-borne diseases (TBDs), significant gaps remain in understanding the interconnectedness of ticks, animal hosts, and human health across Africa. Strengthening diagnostic capacity, adopting a One Health approach, and enhancing cross-border collaboration particularly in areas with high livestock movement are urgently needed. These measures are vital for improving surveillance, preventing and controlling TBDs, and protecting both public health and economic stability across the continent.