Babesia caballi and Theileria equi in ticks from horses in four Indigenous communities of Costa Rica.
Authors: Posada-Guzmán M F, Jiménez-Rocha A E, Sánchez-Bermúdez J F, Romero-Zúñiga J J, Dolz G
Journal: Journal of equine veterinary science
Summary
Equine piroplasmosis, caused by the blood parasites *Babesia caballi* and *Theileria equi*, affects horses throughout Costa Rica, yet the role of tick vectors in transmission had never been formally documented in the country. Researchers collected over 1,000 ticks from 129 horses across four Indigenous communities, identifying tick species and screening 203 ticks from PCR-positive horses for both pathogens using nested PCR; sequencing confirmed 99% genetic similarity to known references. *Dermacentor nitens* dominated the tick population (90.3%), with *Amblyomma mixtum* comprising the remainder, and whilst *Theileria equi* was detected in ticks from 55.3% of infected horses, *Babesia caballi* only appeared in coinfection, establishing for the first time that both vectors are capable of harbouring these hemoparasites in Costa Rica. For practitioners working in Indigenous communities, these findings underscore the importance of integrated tick control strategies and surveillance protocols to limit parasite transmission, though notably the tick sampling occurred in 2011, meaning current vector competence and prevalence may differ. Further investigation into the actual infectivity of these ticks and updated epidemiological monitoring would strengthen disease management and support broader One-Health objectives in these regions.
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Practical Takeaways
- •Implement rigorous tick control programs in Indigenous equine communities, particularly targeting Dermacentor nitens, which carries both major equine piroplasmosis agents
- •Screen horses showing clinical signs of piroplasmosis and test tick vectors to assess local disease burden; consider tick surveillance as part of routine herd health monitoring
- •Work with community stakeholders to establish integrated vector management and disease surveillance systems as part of One-Health initiatives in endemic regions
Key Findings
- •Dermacentor nitens was the predominant tick species (90.3%) infesting horses in Indigenous communities of Costa Rica, followed by Amblyomma mixtum (9.7%)
- •Theileria equi DNA was detected in ticks from 55.3% of piroplasmosis-positive horses; B. caballi was only found in coinfection with T. equi
- •This is the first report of B. caballi and T. equi DNA detection in ticks from Costa Rica, with sequences showing 99% similarity to GenBank references
- •Both Dermacentor nitens and A. mixtum are implicated as potential vectors for equine piroplasmosis transmission in Costa Rica