Fungus Amongus

Tim Iverson

(9/2015) Shrieks of "sss-sssss-snn-snakeeee!" can be heard from frightened men, women, and children anytime an unexpected or unwanted sighting occurs. Snakes can strike fear into the hearts and minds of many and are pervasively vilified throughout our culture. They already suffer from extensive habitat loss and unnecessary killing, but there is a new threat bearing down on these marginalized reptiles. A relatively new disease is slithering across the Eastern United States and infecting these all important predators.

Not much is known about snake fungal disease, or more academically known as Ophidiomyces ophiodiicola, but researchers are currently investigating how it spreads and how to treat this fatal infection. Conservation Magazine, a publication from the University of Washington, reported that in 2006 a New Hampshire population of Timber Rattlesnakes numbered at least 40. Then they began showing symptoms of the infection. Of this infected population, only 19 survived. The fungus affects every snake species differently. In some species it has a near 100% mortality rate, and this spells bad news for the ecosystem as a whole.

This fungus isn’t necessarily new. What does appear to be new is the way it attacks snakes. Matthew Allender, a researcher and professor of biosciences at the University of Illinois, and his team recently published their findings in the Journal of Fungal Ecology. What they’ve found is that the fungus thrives in the soil and consumes dead animals and plants. Ophidiomyces ophiodiicola, or Oo for short, survives by eating keratin. Keratin is the same substance that makes up fingernails, hair, and snake scales along with a long list of other things. What Allender and other researchers believe is that when snakes come out of hibernation it can take a while for their immune system to become fully operational and this is when they pick up the infection. Snake fungal disease begins attacking scales and can cause a whole host of problems for the afflicted. Skin lesions, eye infections, pneumonia, abnormal shedding, ulcers, and other debilitating skin conditions occur as a result of infection. This fungus’s growth slows in colder environments and freezing temperatures. As global temperatures rise and winters become milder in some areas this could spell regional problems and cause snakes to become even more susceptible.

Currently, snake fungal disease has been found in 14 states ranging from Minnesota to Florida. Maryland is not currently identified as an infected state, but neighboring Virginia does have confirmed cases. Since 2006 research has focused largely on diagnosis and treatment. Matthew Allender describes current diagnosis methods as being less invasive and more sensitive than the previous conventional methods. Presently field researchers can take a cotton swab sample on site to test snakes. Previously snakes required biopsies of affected tissues. The new testing method is described as being integral to the research and treatment of affected snakes. "We can know how many [fungal spores] are in a swab, and then we can start to treat the snake and we can watch to see if that number is going down," Allender said. This will hopefully lead to an eventual treatment that can successfully rid snakes of the infection, and beyond that a field application.

Snake fungal disease is similar to another fungal infection wreaking havoc on bat populations in the United States, known as White Nose Syndrome. White Nose Syndrome is caused by a fungus called Geomyces Destructans. This cold loving fungus was also first discovered in 2006. It spreads to hibernating bats and causes erratic behavior. Affected bats will awaken during hibernation with decreased and damaged wing tissue. Flying becomes harder work which depletes energy supplies during times of the year when there is little or no food, which eventually causes starvation and then death. White Nose Syndrome has been confirmed in 19 states and 4 Canadian provinces. In some species it has a mortality rate of 95%.

Illinois Natural History Survey mycologist Andrew Miller said, "The fungus killing these snakes is remarkably similar in its basic biology to the fungus that has killed millions of bats. The snake fungus has the ability, just like the bat fungus, to live as a saprobe, consuming dead organic matter. It doesn’t need the animal to live, but it’s out there attacking the animal now. Why is it doing it? I don’t know." While Matthew Allender is currently leading research on Snake Fungal Disease he thinks it may be a snowball effect that’s just accumulated to this point. He cites pollution, weather/climate events, habitat degradation, and stress from human encroachment as possible culprits to a weakened immune system.

Snakes are a remarkable and highly beneficial keystone species. Snakes are crucial to pest and rodent control for the environment and us. Most of what snakes eat is largely rodents. Rodents, like mice for example, are prone to spreading disease. Often they are carriers of ticks. Ticks can transmit a plethora of pathogens to people including (but not limited to) Rocky Mountain Spotted Fever and Lyme disease. Mice don’t need help from ticks to spread disease though. They are effective enough at it on their own. Through urine and fecal excrement mice are known to transmit salmonella, hanta virus, and plague. Bites or scratches from mice or mites that live on mice can cause rat-bite fever, typhus, and types of pox. Snakes are glad to lend a helping hand in protecting us from all this.

Snakes were already under threat from urbanization and habitat loss. Many snakes only reproduce every second or third year. With the added threat of a fungal epidemic that could spell disaster for regional snake populations. Research has been ongoing since the first discovery in 2006, and now has a multitude of state, national, and non-profit partners. The average person can assist too. The most practical thing an individual can do is to report any potential sighting of disease to wildlife authorities like the Maryland Department of Natural Resources or the USGS National Wildlife Health Center. To help control and prevent the spread of the disease do not capture or relocate any snakes. Bringing a potentially infected snake into your home or to another area can spread the disease to new populations and areas, including any pet snakes that may reside in the home. Finally, cleaning any field gear like snake hooks and snake bags or container boxes can prevent the spread of Snake Fungal Disease as well as other pathogens that snakes can transmit to one another.

There’s no clear end in sight for the treatment and eradication of Snake Fungal Disease. Many researchers, non-profits, and agencies are working together to investigate the epidemic further. If the infection progresses further shrieks from terrified ophidiophobes may become less and less.