Systematic review and meta-regression analysis of the prevalence of tick-borne pathogens in ticks and livestock in Uganda from 1980 to 2024

Tick-borne pathogens (TBPs) cause diseases of significant impact on public health and livestock production in sub-Saharan Africa. In Uganda, livestock production contributes more than 17% of financial share of the agricultural sector. However, this venture is hampered by livestock diseases, especially tick-borne diseases (TBDs). A systematic review and meta-analysis were conducted to estimate the prevalence and distribution of TBPs in order to inform TBD control in Uganda. We retrieved published TBP prevalence articles (n = 6,446) for Uganda (January 1980 - August 2024) from five scientific databases, namely: Scopus, PubMed, Springer Nature, ScienceDirect and Web of Science. Following PRISMA guidelines, 36 studies were included in the meta-analysis. Heterogeneity was assessed using the Cochran's Q statistic. The I² statistic and publication bias were evaluated using the Luis Furuya-Nakamori (LFK) index. Occurrence of TBPs was reported in 24 of the 146 districts of Uganda. Theileria parva (T. parva) was the most predominantly studied TBP representing 55.6% (20/36) of the studies with a national cattle prevalence of 29.2% (95% CI: 18.3-41.4), 62.6% (95% CI: 36.7-85.2) and 15.4 (95% CI: 0.78-42.5) based on DNA, serology and other parasite detection methods, respectively. Majority of the variation in T. parva prevalence in cattle could be explained by the diagnostic method used and sub-national region from which cattle originated. About 71% (17/24) of the districts represented across retrieved publications were located within Uganda's cattle corridor. Data on TBP prevalence in small ruminants (goats and sheep) were very limited, representing only 13.8% (5/36) of the retrieved studies, despite the constraints posed by TBDs on small ruminant production in Uganda. More than half of all the studies retrieved reported T. parva, making it the most frequently reported TBP with an average prevalence of 29.2% in cattle. This is due to the fact that T. parva is the most important cattle TBP in Uganda. Further research on TBPs in data deficient districts, especially in the cattle corridor, is needed in order to support TBD control in Uganda.