Ophidiomycosis, an emerging fungal disease of snakes: Targeted surveillance on military lands and detection in the western US and Puerto Rico

Abstract

Wildlife disease surveillance and pathogen detection are fundamental for conservation, population sustainability, and public health. Detection of pathogens in snakes is often overlooked despite their essential roles as both predators and prey within their communities. Ophidiomycosis (formerly referred to as Snake Fungal Disease, SFD), an emergent disease on the North American landscape caused by the fungus Ophidiomyces ophiodiicola , poses a threat to snake population health and stability. We tested 657 individual snakes representing 58 species in 31 states from 56 military bases in the continental US and Puerto Rico for O . ophiodiicola . Ophidiomyces ophiodiicola DNA was detected in samples from 113 snakes for a prevalence of 17.2% (95% CI: 14.4–20.3%), representing 25 species from 19 states/territories, including the first reports of the pathogen in snakes in Idaho, Oklahoma, and Puerto Rico. Most animals were ophidiomycosis negative (n = 462), with Ophidiomyces detected by qPCR (n = 64), possible ophidiomycosis (n = 82), and apparent ophidiomycosis (n = 49) occurring less frequently. Adults had 2.38 times greater odds than juveniles of being 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 ophidiomycosis. The results of this survey indicate that this pathogen is endemic in the eastern US and identified new sites that could represent emergence or improved detection of endemic sites. The direct mortality of snakes with ophidiomycosis is unknown from this study, but the presence of numerous individuals with clinical disease warrants further investigation and possible conservation action.

Contribution of host species and pathogen clade to snake fungal disease hotspots in Europe

“…However, overall, prevalence was relatively low (8.7%) when compared to studies conducted in North America. of free-ranging snakes in the USA and Canada, with 9.8% observed mortality [30,33].…”

“…However, overall, prevalence was relatively low (8.7%) when compared to studies conducted in North America. Samples collected from 31 states in the U.S. and Puerto Rico detected O. ophidiicola in 17.2% of wild snakes, and a meta-analysis of 33 studies reported overall O. ophidiicola infection in 18.5% of free-ranging snakes in the USA and Canada, with 9.8% observed mortality [30, 33].…”

Genetic mechanisms and biological processes underlying host response to ophidiomycosis (Snake Fungal Disease) inferred from tissue-specific transcriptome analyses

“…O. ophidiicola is a generalist pathogen which is capable of infecting numerous snake species across the phylogeny (31, 33, 92). We acknowledge that the physiological response to this pathogen may vary among different host snake species, but we suspect that the biological mechanisms underlying host response (like immune activation, metabolism, etc.)…”

Introduction to the special issue: Ecoimmunology in ectotherms

“…The emerging fungi pathogens threaten biodiversity more than any other group of microorganisms that can cause disease (Fisher et al, 2012). They are responsible for declines of many taxa, including fishes (Hatai, 2012;Rodger, 2016;Yanong, 2003), amphibians (Blaustein et al, 2018;Grogan et al, 2018;Hussain & Pandit, 2012;Rollins-Smith, 2017), and reptiles (Allender et al, 2020;Lorch et al, 2016;Schumacher, 2003). These declines are especially severe in amphibians, whose populations are declining worldwide (Blaustein et al, 2018;Collins, 2010).…”

“…The ectotherms decline has multiple causes, emphasizing the increased prevalence and outbreaks of diseases caused by emerging pathogens, such as fungus and viruses, in amphibians (Blaustein et al, 2018;Chen & Robert, 2011;Grogan et al, 2018;Hussain & Pandit, 2012;Rollins-Smith, 2017), reptiles (Allender et al, 2020;Lorch et al, 2016;Marschang, 2019;Schumacher, 1997Schumacher, , 2003, and fishes (Hatai, 2012;Rodger, 2016;Yanong, 2003). This increase in the prevalence of pathogens and the resulting diseases, in turn, are associated with climate change and environmental contamination (Becker & Zamudio, 2011;Brem & Lips, 2008;Burrowes et al, 2004).…”