Authors: Cornell Tessa Rose, Fye Biram Laity, Nyassi Edrisa, Ceesay Fatou, Jallow Mahmud, Langendonk R Frèdi, Wootton Dan G, Pinchbeck Gina, Scantlebury Claire Elizabeth
Journal: Frontiers in veterinary science
Summary
# Editorial Summary: Histoplasma Exposure in Gambian Working Equids Epizootic lymphangitis caused by *Histoplasma* species represents a significant welfare concern for working equids in sub-Saharan Africa, yet baseline prevalence data in affected regions has been lacking. Between February and July 2022, researchers recruited 463 horses and 92 donkeys across 18 rural sites in The Gambia, collecting blood samples and detailed management data to establish anti-*Histoplasma* antibody seroprevalence and identify associated risk factors using multivariable logistic regression. Strikingly high seroprevalence was documented—79.9% in horses and 46.7% in donkeys—with mares showing nearly three times greater odds of seropositivity than geldings, whilst younger animals (<2.5 years) demonstrated protective effects, suggesting either age-related exposure patterns or differential survival. Seasonal variation emerged as significant, with horses sampled during the rainy season showing doubled odds of seropositivity, and intriguingly, animals involved in firewood transport showed reduced seropositivity odds, potentially reflecting differential exposure to environmental reservoirs or management practices. Direct *Histoplasma capsulatum* var. *farciminosum* infection, detected via nested ITS-PCR, was confirmed in 22.0% of horses and 5.4% of donkeys, though poor agreement between serological and molecular testing suggests antibody detection may reflect historical rather than current infection, emphasising the importance of integrating diagnostic approaches when assessing disease burden.
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Practical Takeaways
- •Histoplasma exposure is highly prevalent in working equids in The Gambia; routine screening may help identify actively infected animals for management or treatment
- •Younger horses (<2.5 years) appear less exposed, suggesting either age-related acquired resistance or different management practices; consider targeted prevention strategies for at-risk groups like mares
- •Seropositivity increases during rainy season and in herds with previous EL cases; implement enhanced biosecurity and environmental management during high-risk periods
Key Findings
- •Anti-Histoplasma antibody seroprevalence was 79.9% in horses and 46.7% in donkeys in rural The Gambia
- •Mares showed 2.9-fold higher odds of seropositivity compared to geldings/stallions in horses
- •Horses <2.5 years old had significantly lower odds of seropositivity (OR=0.37-0.46) compared to older animals
- •HCF infection prevalence was 22.0% in horses and 5.4% in donkeys, with poor agreement between serological and PCR detection methods