Measuring the trends in tick and tick-borne pathogen studies and their impact on tick-borne disease surveillance in India, Pakistan, Sri Lanka, and Ethiopia: a comparative analysis

Surveillance of tick-borne pathogens (TBPs) harbored by ticks and a variety of human and non-human hosts can help track the range expansion of vectors and the spread of TBPs. Countries with similar geographic landscapes, reservoir hosts, weather patterns, animal movements, and economic activities might have comparable tick and TBPs; monitoring these can help with spillover prevention and timely disease prevention efforts. We compared the countries of India, Pakistan, Sri Lanka, and Ethiopia to determine (i) tick surveillance methods, (ii) methods of tick and TBP detection, (iii) areas where important tick species are present, and (iv) areas where crucial TBPs are present. We compared these countries specifically due to comparable agricultural and animal husbandry practices, socioeconomic conditions, diversity of landscapes, flora, and fauna, transboundary movements, and relative proximity, which dictates the kinds of ticks present and conditions for pathogen dissemination. Surveillance gaps were identified, including underrepresentation of ecologically diverse or remote regions, limited human and wildlife sampling, and a lack of non-targeted pathogen detection approaches. Shared tick species (Rhipicephalus microplus, Haemaphysalis bispinosa, and Hyalomma anatolicum) and TBPs were observed across countries with similar livestock production and climates, suggesting parallel ecological drivers of tick and pathogen distribution. We discuss the geographic variation in the vector tick species, TBPs, mechanisms used for tick surveillance, and the need for integrated One Health surveillance. Future studies should delve into comparing ecological mechanisms occurring in multiple countries that might be driving the occurrence of zoonotic tick-borne diseases and prevention measures to reduce the burden of TBPs.