Urbanization Is Associated With Increased Severity of Ophidiomycosis, a Fungal Disease in Snakes

Ophidiomycosis, caused by the fungal pathogen Ophidiomyces ophidiicola, is an emerging infectious disease affecting numerous snake species and posing a potential threat to biodiversity. Additional surveillance of ophidiomycosis in the southeastern USA's resident snake populations is needed, and the effects of urbanization on disease dynamics remain poorly understood. Thus, our research aimed to 1) document the occurrence, prevalence, and severity of ophidiomycosis in free-ranging snakes in Florida, Louisiana, and Mississippi, USA; and 2) determine whether urbanization was associated with differences in disease prevalence and severity using paired urban and non-urban systems. During 2022–24, we sampled 496 individual snakes comprising 42 species, detecting O. ophidiicola in 22% of individuals. Our study documented evidence of infection in several snake species within the region and provided a published record of ophidiomycosis in Mississippi. Analysis of paired urban and non-urban systems revealed no significant difference in ophidiomycosis prevalence between sites. However, infection severity scores were significantly higher in urban sites than in non-urban sites, with mean severity scores ranging from 7.50–8.80 (on a scale of 0–12) in urban sites and 4.80–5.67 in non-urban sites. Our findings highlight the complex relationship between ophidiomycosis and urbanization in snake populations in the southeastern USA. These results suggest that more severe disease presentation, even without increased infection prevalence, may be associated with urban environments, underscoring the importance of considering habitat quality and protection in conservation efforts and wildlife disease management strategies.