Grazing system and Hyalomma marginatum tick infestation in cattle with high prevalence of SFG Rickettsia spp.

Tick-borne diseases (TBDs) represent a significant portion of infectious diseases of global public health interest. In Italy, knowledge about the occurrence of tick-borne pathogens (TBPs) in ticks parasitizing cattle is scarce. In this research, we focused on ticks infesting Maremmana cattle grazing in open pasture and silvopasture systems. After being morphologically identified, ticks were molecularly tested for the presence of pathogens of the genus Rickettsia. Of the 794 ticks detected, 117 were collected, being the majority Hyalomma marginatum (72.6%), followed by other Hyalomma species (23%), Rhipicephalus turanicus (1.7%), Rh. bursa (0.9%), Hy. lusitanicum (0.9%) and Dermatocentor marginatus (0.9%). All ticks were adults, 58.1% males and 41.8% females. The highest tick prevalence was noted in April for silvopasture system cattle (90%), and in May for open pasture ones (85%). TBPs were detected only in Hy. marginatum, and all belong to Rickettsia spp. of zoonotic interest. In particular, 21/40 (52.5%) ticks scored positive for Rickettsia spp. by gltA gene and of these 15/21 (71.4%) also to spotted fever group (SFG) rickettsiae by ompA gene. Of the total positive specimens, 19 were successfully sequenced and scored Rickettsia aeschilimannii (17/19, 89.5%), R. slovaca (1/19, 5%), and R. massiliae (1/19, 5%). This research highlights the potential impact of grazing systems on cattle parasitization by hard ticks. The molecular investigation of TBPs in ticks collected from Maremmana cattle shed light on the presence of pathogenic bacteria of SFG Rickettsia spp., pointing out the potential risk of TBPs transmission between livestock and humans.

Ticks and tick-borne pathogens of domestic animals in Somalia and neighbouring regions of Ethiopia and Kenya.

Ticks and tick-borne pathogens (TBPs) of domestic animals in Somalia and neighbouring regions of Ethiopia and Kenya are reviewed to identify knowledge gaps in these regions, where unrestricted livestock movements across borders are common. Major scientific databases, such as PubMed, Web of Science, Scopus, CABI, and Google Scholar were searched, to retrieve articles based on papers published between 1960 and March 2023. Thirty-one tick species representing six genera (Rhipicephalus, Hyalomma, Amblyomma, Haemaphysalis, Ornithodoros and Argas) were reported to infest domestic animals, mainly livestock. Overall, the most represented species were Rhipicephalus pulchellus (up to 60% of specimens identified), followed by Hyalomma dromedarii (up to 57%), Hyalomma truncatum (up to 57%), Amblyomma lepidum (up to 21%), Amblyomma variegatum (up to 21%) and Amblyomma gemma (up to 19%), with morphological characterization being the principal method of tick identification. In addition, 18 TBPs, including zoonotic pathogens (e.g., Crimean-Congo haemorrhagic fever virus), were detected, with Babesia spp., Theileria spp., and Rickettsia spp. being the most commonly reported. Half of the pathogens documented were detected using molecular techniques, while the other half were detected by serology and microscopic techniques. Generally, ticks and TBPs in the region are under-studied, particularly, data relating to pet animals and equines is lacking. Further, the infection intensity and herd prevalence of ticks and TBPs is unclear because of insufficient data and poor approaches to quantitative analysis, making it difficult to propose management policies in the region. There is an urgent need, therefore, for more and better studies, particularly those that take a 'One Health' perspective, focusing on the prevalence and socioeconomic impact of ticks and TBPs in animals as well as in humans, so that sustainable control strategies against them can be planned.