Equine Infectious Anemia Virus (EIAV): Evidence of Circulation in Donkeys from the Brazilian Northeast Region.
Authors: Costa Viviane Maria Dias, Cursino Andreia Elisa, Franco Luiz Ana Paula Moreira, Braz Gissandra Farias, Cavalcante Paulo Henrique, Souza Cintia de Almeida, Simplício Kalina Maria de Medeiros Gomes, Drumond Betania Paiva, Lima Mauricio Teixeira, Teixeira Bruno Marques, Kroon Erna Geessien
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: EIAV Circulation in Brazilian Donkeys Equine infectious anemia remains a notifiable disease with serious welfare implications, yet its epidemiology in donkeys has received minimal research attention despite their potential role in transmission dynamics. Researchers in Ceará, Brazil screened 124 shelter donkeys using multiple diagnostic approaches—AGID, ELISA (with both rgp90 and rp26 recombinant proteins), and PCR targeting the tat-gag gene—revealing substantial serological evidence of EIAV exposure that conventional testing alone would have missed. Whilst only 0.81% tested positive by AGID, recombinant protein ELISA detected antibodies in 21.8% (rgp90) and 10.5% (rp26) of animals, with proviral DNA confirmed in 8.8% by PCR; phylogenetic analysis linked donkey strains to existing Brazilian Pantanal variants, suggesting active circulation rather than historical exposure. These findings challenge the assumption that donkeys are incidental hosts and indicate they may maintain and transmit EIAV in endemic regions, with important implications for quarantine protocols and disease surveillance in mixed equine facilities. Practitioners managing multi-species equine operations—particularly in areas where donkeys and horses share grazing or where shelter animals are introduced—should consider donkeys as potential reservoir hosts and factor this into biosecurity and testing strategies.
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Practical Takeaways
- •Donkeys can harbor EIAV and transmit it to horses; diagnostic screening should include ELISA and PCR rather than relying solely on AGID
- •Shelters and facilities housing both donkeys and horses should implement biosecurity measures to prevent EIAV transmission between species
- •EIAV control programs must include donkey populations in endemic regions, not just equines, as current OIE protocols may not adequately address donkey carriers
Key Findings
- •Only 0.81% (1/124) of donkeys tested positive by AGID, but 21.8% tested positive by rgp90 ELISA and 8.8% had detectable proviral DNA by PCR
- •Discordance between AGID and ELISA methods suggests AGID may underdetect EIAV infection in donkeys
- •Phylogenetic analysis confirms EIAV sequences from donkeys group with Pantanal Brazilian strains, indicating circulation in the Brazilian Northeast
- •Donkeys are confirmed as carriers of EIAV and potential sources of infection for other equids