Spatiotemporal distribution, species diversity, and burden of ixodid ticks on cattle in Northwest Ethiopia

Abstract

Ixodid ticks are important arthropods in medicine and veterinary science, posing a considerable threat to livestock in East Africa. A repeated cross-sectional study was conducted from March 2022 to June 2023 to explore the spatial distribution, prevalence, species diversity and burden of cattle ticks, and to investigate risk factors associated with tick infestation prevalence and burden in northwest Ethiopia. A total of 2528 cattle were randomly selected through multistage cluster sampling for tick inspection across 18 districts during both dry and wet seasons. Ticks samples were identified morphologically at the genus and species levels. Data were analysed using descriptive statistics and mixed-effect logistic regression models. In total, 22,698 adult ticks were found from 1604 cattle; of which 10,246 were collected for identification, and revealed ten tick species across three genera: Amblyomma, Rhipicephalus, and Hyalomma. The predominant species included A. variegatum (35.5 %), R. decoloratus (32.73 %), A. lepidum (10.64 %), and H. rufipes (6.85 %), while R. sanguineus and H. analoticum were below 1 %. Tick diversity was highest in Kafta-Humera, followed by Wolkait and Tsegede. The overall tick infestation prevalence was 63.45 %, with a mean tick burden of 8.98 ± 0.31 ticks per animal, both significantly impacted by agroecology, season, vegetation cover, management, and coexistence with other livestock species (p < 0.05). Infestation rates varied notably among districts, with Wolkait having the highest at 94.49 % and Wogera the lowest at 9.17 %. This study underscores the high prevalence of tick infestations and the diverse ixodid tick species of veterinary importance in the region, highlighting the need for effective tick management strategies. Studies are recommended to explore the epidemiological features of relevant tick-borne pathogens