"The fungus Oo and the parasite Ro appear to be the most important infectious agents in free-ranging snakes in the southeastern US."
— Dr. Corinna Mishin, University of Georgia
A new study published in Frontiers in Veterinary Science has surveyed seven pathogens in over 500 wild snakes across the southeastern United States, revealing critical insights into snake health and disease transmission.
Key Findings
- The fungus Ophidiomyces ophidiicola (Oo), which causes ophidiomycosis, and the parasite Raillietiella orientalis (Ro) were identified as the most significant infectious agents.
- Coinfections were common: 44% of snakes carried multiple pathogens, and these coinfections were strongly associated with an increased risk of ophidiomycosis.
- Pathogen prevalence varied by species: Pygmy rattlesnakes were most likely to carry both Oo and Ro; other species showed lower infection rates.
- Geographic and physical factors mattered: Snakes in Georgia had higher Oo prevalence; Ro was found only in Florida. Skin lesions were directly linked to Oo presence.
- Most common pathogens: Salmonella enterica (63%) and Hepatozoon spp. (53%) were widespread. Antibiotic-resistant Mycoplasma spp. (18%) was reported for the first time in wild US snakes.
Background
The study sought to build a broader picture of snake health beyond single-pathogen analysis. Researchers captured snakes at two wildlife refuges—one in South Carolina and one in Florida—and also sampled opportunistically across the broader southeastern US. Live snakes were swabbed and blood sampled; carcasses underwent postmortem examinations.
Limitations and Implications
- Sampling was limited to a few counties, so results may reflect local habitats rather than general conditions.
- Ro prevalence was likely underestimated due to difficulties in detecting the parasite in fecal samples.
- The findings directly inform conservation efforts, particularly concerning pathogen spillover from captive and invasive species such as Burmese pythons and brown anoles, which are known competent hosts for Ro.
Researcher Statement
"Increased risks of ophidiomycosis was strongly associated with coinfections."
Dr. Mishin also noted that certain species—such as rattlesnakes, which face higher persecution risks—may be more susceptible to infection and subsequent disease.