Mixed infection of Leishmania (Leishmania) infantum and Leishmania (Viannia) braziliensis in a mare (Equus ferus caballus) from Minas Gerais State, Southeastern Brazil.
Authors: Martins Anna Luiza Moreira, Estevam Letícia Gracielle Tôrres de Miranda, Freire Marina Andrade, Lima Ana Cristina Vianna Mariano da Rocha, de Oliveira Flávia Carvalho Bitencourt, Dutra-Rêgo Felipe, Carvalho Gustavo Mayr de Lima, Ribeiro Vitor Márcio, Paz Gustavo Fontes
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Equine leishmaniasis in Brazil presents a diagnostic challenge that practitioners may not routinely encounter, as disease manifestations typically involve a single Leishmania species—most commonly *Leishmania (Viannia) braziliensis*, with *L. (L.) infantum* appearing only sporadically in equine cases. This case report documents a naturally occurring mixed infection in a 6-year-old mare presenting with nodular cutaneous lesions across all four limbs but otherwise clinically stable, investigated through parasitological examination and molecular techniques targeting the hsp70 gene and ITS1 region in skin and bone marrow samples. Notably, both parasites were identified concurrently, and this represents the first confirmed isolation of *L. (V.) braziliensis* directly from equine cutaneous lesions, suggesting that horses may harbour species previously thought to preferentially infect other mammalian hosts. The clinical significance lies in recognising that equids can act as reservoir hosts for multiple Leishmania species simultaneously, complicating both individual case management and regional epidemiological surveillance efforts, particularly in endemic areas where multiple transmission cycles may operate. Clinicians should consider mixed infections when nodular cutaneous lesions prove refractory to standard treatments or present atypically, and molecular diagnostic confirmation is advisable in suspected equine leishmaniasis cases to guide appropriate management and inform local disease control strategies.
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Practical Takeaways
- •Equine practitioners in endemic areas (Brazil, particularly Minas Gerais) should recognize nodular cutaneous lesions on limbs as potential leishmaniasis cases and submit samples for molecular confirmation
- •Mixed Leishmania infections are possible in horses; single-species diagnosis should not exclude further investigation, as treatment and epidemiological implications differ between species
- •Horses with cutaneous leishmaniasis represent a disease reservoir; appropriate biosecurity measures and epidemiological reporting are critical for regional disease control efforts
Key Findings
- •First confirmed isolation of L. (V.) braziliensis from equine cutaneous lesions in a 6-year-old mare
- •Mixed infection with both L. (V.) braziliensis and L. (L.) infantum confirmed via hsp70 gene and ITS1 region molecular analysis
- •Nodular cutaneous lesions on all limbs were the primary clinical manifestation without systemic health issues
- •Equids confirmed as potential reservoirs in leishmaniasis transmission in Southeastern Brazil