An emerging snake disease is much more widespread than expected

Worldwide, many species of snakes are in a state of decline as a result of habitat loss, climate change, and infectious diseases. In a new study from the University of Illinois,  scientists have teamed up with military service members to investigate the prevalence of an emerging snake disease.

With the help of personnel on military bases across 31 states in the U.S., the researchers analyzed snake samples to detect a fungal pathogen which causes ophidiomycosis, a potentially deadly disease.

The study revealed that the fungus is much more widespread that what was previously known. The team identified infected snakes on military bases in 19 states and Puerto Rico.

“Ophidiomycosis – formerly known as ‘snake fungal disease’ – is an emerging infectious disease caused by the fungus Ophidiomyces ophidiicola,” said study lead author Dr. Matt Allender. “It has been documented in over 15 genera of wild and captive snakes. Infection with the pathogen causes a wide range of clinical signs in snakes, from difficulty shedding skin, to crusts and ulcers on the head and body, and even death in some cases.”

“We looked for this pathogen in samples from 657 snakes and found that 17% were infected. Our findings include the first reports of this disease in Oklahoma, Idaho and Puerto Rico.”

The health and abundance of snakes are important to human health, as snakes control populations of small mammals that carry and amplify pathogens that also cause disease in humans such as hantavirus and Lyme disease, said Dr. Allender. He noted that natural lands on military bases provide an unexpected sanctuary for many threatened or endangered species.

The research was focused on swab samples that represented 58 species of snakes. The researchers used a tool they developed to amplify DNA molecules so they could measure the extent of infection. The biologists who collected the samples inspected the snakes for scabs or other signs of disease. 

The fungal pathogen was detected in samples from 113 snakes, including copperheads, eastern diamondback rattlesnakes, Puerto Rican boas, sidewinders, and whip snakes. 

According to the researchers, adult snakes were the most likely to be diagnosed with ophidiomycosis. “Snakes from Georgia, Massachusetts, Pennsylvania, and Virginia all had greater odds of ophidiomycosis diagnosis, while snakes from Idaho were less likely to be diagnosed with the disease,” they noted.

Dr. Allender explained that the pattern of infection likely reflects a larger distribution of the disease in snakes in the eastern U.S. than previously thought, and its possible expansion from east to west. The disease was first confirmed in 2006 in a population of timber rattlesnakes in New Hampshire.

“Ophidiomycosis has potentially serious consequences for the success of snake conservation efforts in North America, threatening biodiversity across several habitats,” said Dr. Allender.

The study is published in the journal PLOS ONE.

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By Chrissy Sexton, Earth.com Staff Writer