High Diversity and Low Coinfections of Pathogens in Ticks from Ruminants in Pakistan

Emerging tick-borne infections pose growing public health threats, causing global disease burdens and economic losses. In this study, tick-borne pathogens were detected in ticks collected from ruminants in 19 sites of Khyber Pakhtunkhwa Province, Pakistan, between 2023 and 2024. A total of 989 ticks, belonging to five species, i.e., <i>Hyalomma marginatum</i>, <i>Rhipicephalus microplus</i>, <i>Rhipicephalus sanguineus</i>, <i>Rhipicephalus haemaphysaloides</i>, and <i>Haemaphysalis bispinosa</i>, were tested by specific PCR followed by Sanger sequencing. In total, fourteen pathogens including two <i>Anaplasma</i> species, three <i>Ehrlichia</i> species, three <i>Rickettsia</i> species, one <i>Babesia</i> species, and five <i>Theileria</i> species were identified, with an overall infection rate of 20.2% (95% CI: 17.7-22.7%). Phylogenetic analyses revealed two undefined <i>Ehrlichia</i> species: <i>Candidatus</i> Ehrlichia hyalommae was exclusively detected in <i>Hy</i>. <i>marginatum</i> ticks, while <i>Candidatus</i> Ehrlichia rhipicephalis was only found in <i>R. microplus</i>. Additionally, an undefined <i>Rickettsia</i>, provisionally named <i>Candidatus</i> Rickettsia pakistanensis, was identified, which is phylogenetically close to <i>R. sibirica</i> in North Asia and <i>R. africae</i> in Africa, suggesting its potential pathogenicity to humans. Although coinfections of two pathogens were observed, the coinfection rates were quite low. The findings revealed a significant diversity of tick-borne pathogens in Pakistani ticks, which may pose risks to livestock and humans.