Molecular detection of tick-borne pathogens in cattle ticks from the Lao People's Democratic Republic

Tick-borne pathogens threaten livestock health and productivity in Southeast Asia. Despite growing regional interest, epidemiological data from the Lao People's Democratic Republic (Lao PDR) remain insufficient and underreported.

We collected 227 ticks from 63 cattle across northern, central, and southern Lao PDR. Species were morphologically identified as Rhipicephalus microplus and Rhipicephalus sanguineus sensu lato and confirmed by sequencing of the cytochrome c oxidase subunit I gene. Pathogen screening was conducted via polymerase chain reaction (PCR), with sequence identities verified using the GenBank database. Multivariate analyses assessed regional variation.

Detected pathogens included the apicomplexan protozoans Babesia bigemina (7%), Babesia bovis (2.6%), and Theileria sp. (10.6%) as well as the bacteria Anaplasma marginale (18.9%), Anaplasma sp. (2.2%), Ehrlichia sp. (6.6%), Ehrlichia minasensis (0.4%), and Aureimonas altamirensis (1.3%). Anaplasma marginale was the most prevalent. Codetections were common, with multiple ticks harboring two or more pathogens. Some double detection occurred more frequently than expected by chance.

This study presents the first comprehensive evidence of diverse tick-borne pathogens circulating in cattle ticks from Lao PDR, revealing high genetic similarity to globally recognized strains alongside distinct region-specific detection patterns. Notably, it also constitutes the first report of A. marginale, E. minasensis, B. bigemina, B. bovis, and Theileria sp. in cattle ticks in the country. These findings underscore the urgent need for integrated tick and pathogen surveillance within a One Health framework, with significant implications for regional disease monitoring, livestock health management, and zoonotic risk mitigation.