Epidemiology of tick‐borne pathogens in the semi‐arid and the arid agro‐ecological zones of Punjab province, Pakistan

Tick‐borne diseases ( TBD s) have a large impact on animal health and the livelihood of livestock owners, particularly in developing countries. Although climatic and ecological conditions in Pakistan may favour the transmission of tick‐borne pathogens ( TBP s), only a few systematic studies have been carried out on TBP s and the diseases that they cause in this country. To improve our understanding of the distribution of TBP s, 3,807 ticks were collected from ruminants ( n  = 369) on 108 livestock farms (semi‐arid zone = 36, arid zone = 72) in Punjab Province. After morphological identification ticks were pooled into 405 pools ( Hyalomma anatolicum  = 300, Rhipicephalus microplus  = 89, Hyalomma dromedarii  = 9, Rhipicephalus turanicus  = 7) based on their species, locality of collection, and the host. DNA from each pool was screened by a Reverse Line Blot ( RLB ) hybridization assay for the presence of Anaplasma, Ehrlichia , Rickettsia , Babesia, and Theileria species. DNA from at least one TBP was found in 142 (35.1%) pools. Among the positive pools, 91 (64.1%) had a mixed infection with two or more TBP s, whereas 51 (35.9%) pools were infected with a single TBP . The detected pathogens not only included species that were known to be endemic in Pakistan, such as Theileria annulata (6.7%), Theileria orientalis (3.5%), Anaplasma marginale (5.7%), Anaplasma centrale (2.7%), Anaplasma ovis (1.5%), Babesia bigemina (0.7%), and Babesia bovis (0.2%), but also several TBP s that had not been reported to occur in Pakistan before. This included Ehrlichia minasensis (3.2%), an Anaplasma platys ‐like organism (1.2%), Babesia occultans (0.2%), and Rickettsia massiliae (0.2%), as well as two previously uncharacterized species: Ehrlichia sp. Multan (18.0%) and Anaplasma sp. ( BL 099‐6) (2.22%). The pathogenicity of these novel species remains to be examined. This study shows that a much broader spectrum of TBP s is present in Pakistan than previously thought, including several zoonotic pathogens.