Genetic Characterization of Piroplasms in Donkeys and Horses from Nigeria.
Authors: Sunday Idoko Idoko, Tirosh-Levy Sharon, Leszkowicz Mazuz Monica, Mohammed Adam Babagana, Sikiti Garba Bello, Wesley Nafarnda Daniel, Steinman Amir
Journal: Animals : an open access journal from MDPI
Summary
Equine piroplasmosis, transmitted by ticks and caused by *Theileria equi* and *Babesia caballi*, poses a significant threat to equid populations across West Africa, where Nigeria's position as a major animal transport hub may facilitate regional disease spread. Researchers used PCR-based molecular characterisation to detect and genetically profile piroplasm infections in 57 donkeys and 47 horses from northern Nigeria, with serological testing via immunofluorescence antibody test to assess exposure history. Donkeys bore a substantially higher parasitic burden than horses—43.8% infected with *T. equi* and 8.8% with *B. caballi*, including 5.3% harbouring both species simultaneously—whilst only 8.5% of horses were *T. equi* positive; notably, four distinct 18S rRNA genotypes (A, B, C and D) circulated within the *T. equi* population, indicating considerable genetic diversity. The identification of multiple *T. equi* genotypes coupled with high seroprevalence in donkeys (42.3% anti-*T. equi*, 55.8% anti-*B. caballi*) suggests donkeys function as important parasite reservoirs in the region. These findings carry substantial implications for practitioners managing equid health in West Africa: donkeys warrant screening and monitoring protocols equivalent to horses, biosecurity measures should account for donkey-mediated transmission risk, and awareness of circulating genotype diversity may inform future diagnostic and vaccine development strategies.
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Practical Takeaways
- •Donkeys in West Africa carry significantly higher piroplasm infection rates than horses and may serve as disease reservoirs—implement targeted screening and tick control for donkey populations
- •The presence of multiple T. equi genotypes suggests diverse parasite strains circulating in the region; consider this genetic diversity when selecting diagnostic tests and treatment protocols
- •Nigeria's role as an animal transport hub increases risk of EP dissemination across West Africa—veterinarians should maintain high clinical suspicion and implement biosecurity measures for imported equids
Key Findings
- •43.8% of donkeys (25/57) were infected with T. equi compared to 8.5% of horses (4/47)
- •Four of five known T. equi 18S rRNA genotypes (A, B, C, D) were identified, demonstrating high genetic variation
- •5.3% of donkeys (3/57) had dual T. equi and B. caballi infections; all B. caballi isolates were rap-1 genotype A1
- •42.3% of donkeys were seropositive for anti-T. equi antibodies and 55.8% for anti-B. caballi antibodies by IFAT