Ticks and Tick-Borne Microorganisms in the United Arab Emirates: Diversity, Abundance, and Research Gaps

The United Arab Emirates, like the rest of the world, is experiencing the effects of climate change, which significantly influences the abundance and distribution pattern of ticks and tick-borne microorganisms. Other factors, such as land use changes and habitat fragmentation, also contribute to the complexity of tick population dynamics. This review aims to assess the diversity of ticks infesting livestock and wildlife, analyze the variety and abundance of tick-borne microbes in the context of climate change, and identify research gaps in the field of tick studies within the country. A total of seventeen tick species belonging to four genera have been reported: Amblyomma gemma, A. lepidum, Hyalomma anatolicum, H. excavatum, H. impeltatum, H. dromedarii, H. marginatum, H. truncatum, H. hussaini-like, H. scupense, H. rufipes, Rhipicephalus appendiculatus, R. evertsi, R. pulchellus, R. sanguineus, R. sulcatus, and Ornithodoros muesebecki. The most commonly reported genera, Hyalomma and Rhipicephalus, are typically found on animals. Additionally, eight tick-borne microbes have been detected in ticks and animals, including Crimean–Congo hemorrhagic fever (CCHFV), Anaplasma phagocytophilum, Coxiella-like endosymbiont, Coxiella burnetii, Francisella-like endosymbiont, Rickettsia sp., Theileria annulata, and T. ovis. Microbiome studies in the UAE revealed that the microbial communities associated with H. dromedarii ticks vary throughout the year, with different bacterial genera dominating at different times. Dominant genera, such as Staphylococcus, Bacillus, Francisella, and Corynebacterium, have been consistently reported. Tick populations depend on a combination of large-scale climate influences, microclimates, host densities, and tick predators. Extreme temperatures, both hot and cold, and low humidity can reduce tick activity and survival, while excessive rainfall also inhibits their activity. The risk of human infection increases with the density of infected ticks, which varies locally. The study of ticks and pathogen lifecycles, microbial interactions, and host and habitat ranges is essential for targeted interventions.