The Saharan antelope addax (Addax nasomaculatus) as a host for Hyalomma marginatum, tick vector of Crimean-Congo hemorrhagic fever virus

Abstract

Tick infestation and pathogen prevalence in ticks infesting the Saharan antelope addax (Addax nasomaculatus) are factors that may constitute a risk for both human and animal health. In this study we describe season distribution of adult Hyalomma marginatum and analyzed the tick-borne pathogens and their seroprevalence in natural-living addax in Morocco. The results showed that addax is an important host species for H. marginatum adults. The seroprevalence of Bluetongue virus (BTV; 61.5–92.3%, n = 8/13-84/91), Coxiella burnetii (36.3–69.2%, n = 33/91-9/13) and Brucella spp. (0.0–4.8%, n = 0/50-2/42) was characterized in addax during various years (sampled animals per year, n = 13–91). Presence of Aigai virus (AIGV), a recent taxonomic differentiation of Crimean-Congo hemorrhagic fever virus (CCHFV) of 100% (4/4, years 2016 and 2017) together with Babesia ovis (75%, 3/4, year 2014), Anaplasma spp. (75%, 3/4, year 2014), Rickettsia spp. (50%, 2/4, year 2014) and Theileria spp. (25%, 1/4, year 2014) was observed in H. marginatum collected from the addax (4 pools of 10 adult ticks each). The results support the role of addax host in H. marginatum life cycle and exposure to AIGV and other tick-borne pathogens. The development of control interventions including anti-tick vaccines for wildlife species will contribute to the implementation of effective measures for the prevention and control of tick-borne diseases and might be relevant for the preservation of this threatened species and others such as Arabian oryx (Oryx leucoryx) and African elk (Taurotragus oryx) that share habitat.