First report of SARS-CoV-2 co-infection with chronic dermatophytosis in a lion (Panthera leo) ex situ at Colombia.

BACKGROUND: Coronaviruses affecting humans traditionally caused mild respiratory infections. However, new zoonotic strains such as MERS-CoV (2012) and SARS-CoV-2 (2019) have led to severe acute respiratory syndromes. Since 2020, SARS-CoV-2 has been detected in several animal species, including pets (dogs, cats, ferrets), zoo animals (lions, tigers, snow leopards), and wild fauna (deer). Felids appear especially susceptible, with confirmed infections and deaths in large cats under human care. This raises concerns about reverse zoonosis and the need for strict biosecurity in zoological institutions. CASE PRESENTATION: We report the first documented case of natural co-infection by SARS-CoV-2 and dermatophytosis in an African lion (Panthera leo) ex situ in Latin America. The 17-year-old male, housed at the Barranquilla Zoo (Colombia), had been receiving treatment for Microsporum canis infection when he developed symptoms including nasal discharge, apathy, and anorexia. Real-time RT-PCR confirmed SARS-CoV-2 infection in both the lion and one of his zookeepers. Whole genome sequencing identified a Delta-like variant (AY.125) in both, suggesting interspecies transmission. Clinical management included fluid therapy, antibiotics, antifungals, and supportive care. The lion showed complete recovery within 18 days, with negative RT-PCR results by day 23. Two female lions sharing the enclosure remained negative. CONCLUSIONS: This represents the first report of a natural SARS-CoV-2 and M. canis co-infection in a large felid in Latin America. The findings support humans as the probable infection source and highlight the risk of reverse zoonosis in zoological environments. The case also suggests that immunosuppression may predispose animals to viral infection and secondary fungal disease. Implementing a One Health approach, including staff vaccination, surveillance, and animal biosecurity measures, is crucial to prevent zoonotic transmission and protect susceptible wildlife species under human care.