Authors

Discussion

Background

Northwestern Nigeria is an important hub within a vast regional transboundary livestock trade network through which thousands of animals raised in the semi-arid Sahel must pass each year to fulfill the demand for meat in the densely populated coastal regions to the south. This network can facilitate the rapid spread of pathogens across large distances, especially in the absence of any form of importation control at borders. Ticks and tick-borne pathogens present a well-established threat to livestock health in the region but almost no work has been done to assess the impact of transboundary livestock trading on their diversity, distribution and epidemiology. This study aimed to establish fundamental information about the diversity of ticks infesting cattle and camels.

This study aims at documenting the fauna of ticks at different time of the year in Northwestern Nigeria and molecularly assessing the occurrence of Apicomplexan tick-borne pathogens from cattle and camel tick species in Northwestern Nigeria. 

Method

Three surveys of ticks infesting cattle in Zamfara and Sokoto state of Northwestern Nigeria were carried out in 2017, 2019 and 2021. The ticks were identified morphologically to the species level and were screened molecularly, first using Apicomplexan-specific nested Polymerase Chain Reaction and in comparison, the positive results were screened again using Next Generation Sequencing (NGS) targeting a broad range of apicomplexan species.

Results

600 adult tick species were collected from a total of 169 livestock across the 3 sampling years. Between the years, 5 livestock markets were surveyed for tick on both cattle and camels. Overall 9 tick species were encountered in both states - Amblyomma variegatum, Hyalomma dromedarii, Hyalomma truncatum, Hyalomma rufipes, Hyalomma impressum, Hyalomma impeltatum, Hyalomma marginatum, Rhipicephalus boophilus decoloratus and Rhipicephalus sanguineus. Across the year, the camel tick Hyalomma dromedarii showed consistency in dominating other less common tick species. Notably is the absence of Amblyomma variegatum in 2017 but accounted for 17% and 30% in 2019 and 2021 respectively revealing an increasing prevalence in the region while Hyalomma impeltatum showed a declining trend from 37% in 2017 to 13% in 2019 and 7% in 2021. The molecular results revealed the presence of apicomplexan species as - Theileria annulata, Theileria mutans, Theileria velifera, Babesia cabali, Babesia occultans, and free-living apicomplexan species.

Conclusion

The study affirms the presence of a wide variety of tick species in Northern Nigeria, with a particularly notable prevalence of the camel tick, Hyalomma dromedarii, among cattle. This suggests the encroachment of desert-adapted tick species into regions experiencing discernible effects of climate change. Shedding light on the epidemiology of tick species infesting livestock in Northwest Nigeria, an area pivotal in the regional transboundary livestock trade network, the research highlights the significance of comprehending the dynamics of tick diversity and distribution, especially in the context of livestock trade, which can expedite the spread of pathogens over extensive distances.

The molecular analysis of ticks has yielded valuable insights into the presence of apicomplexan tick-borne pathogens, underscoring the necessity for ongoing monitoring and surveillance efforts to mitigate the risk of disease transmission in livestock populations. These findings underscore the imperative for proactive measures and targeted interventions aimed at managing tick populations and alleviating the impact of tick-borne diseases on livestock health and the agricultural economies of the region. Looking ahead, further research is essential to thoroughly evaluate the impact of transboundary livestock trade on tick diversity, distribution, and disease transmission dynamics in Northwest Nigeria. Such endeavours will play a pivotal role in informing evidence-based strategies for disease prevention and control, thereby safeguarding the health and productivity of livestock populations in the region.