Epidemiology of Ophidiomycosis in Lake Erie Watersnakes (Nerodia Sipedon Insularum)

The population genetics of the causative agent of snake fungal disease indicate recent introductions to the USA

“…Hybridization between lineages is expected to occur more frequently in regions with high prevalence of multiple Oo lineages (i.e., more opportunities for coinfection with strains from distinct lineages). Relatively high prevalence (44% to 78%) has been reported in some snake populations [39][40][41][42], which demonstrates the potential for repeated exposure and coinfection. Factors such as host behavior, host pathogen loads, and environmental parameters, all of which likely vary based on geography, could influence transmission rates and prevalence, resulting in different frequencies of recombination among Oo strains.…”

Factors Predicting Apparent Ophidiomycosis in Wild Brown Watersnakes (Nerodia Taxispilota)

“…The authors reported that >57% (19/33) of N. taxispilota exhibited clinical signs (i.e., lesions) of ophidiomycosis or tested positive for O. ophidiicola (Haynes et al 2020), and this was one of the 34 species with the highest prevalence of ophidiomycosis. More recently, a study on N. s. insularum reported that a mean of 65–78% among 837 individuals across 4 yr tested positive for O. ophidiicola (Haynes et al 2022), suggesting that other Nerodia spp. may also be at relatively high risk of infection.…”

“…Although less urbanized, the Steel Creek site has a unique history of contaminant exposure (e.g., Hg and radiocesium) and disturbance due to historical nuclear production activities on the SRS (Burger et al 2001; Haskins et al 2021a, c). Recent research by Haynes et al (2022) suggests that many factors (e.g., land cover type, soil characteristics, urbanization, chemical applications) may impact the likelihood of ophidiomycosis in snake populations. Unfortunately, our study did not quantify snake population density or perform an in-depth examination of land cover characteristics.…”

“…An important consideration in our study is that snakes were captured after visual detection, which probably biases our sample collection towards snakes with ophidiomycosis (Haynes et al 2022). Snakes are reported to increase basking to mediate immune costs in response to O. ophidiicola infection (McBride et al 2015; Tetzlaff et al 2017), but the habitat used by N. taxispilota on the Savannah River makes it difficult to sample by using traditional methods (e.g., funnel or minnow traps).…”

Report on the First Global Amphibian and Reptile Disease (GARD) Conference 2022

“…By 2012, the pathogen had been detected throughout the East Coast of the United States and has since spread across the central United States (Lorch et al ., 2016). Furthermore, studies since 2017 have detected apparent Oo infections (i.e., clinical signs and Oo detection) in up to 70% of Lake Erie water snakes ( Nerodia sipedon insularum ), with a wide variety of clinical presentations (Haynes et al ., 2022c). Mechanisms for these differences are not known, but host immune response has been hypothesized to possibly play a role (Haynes et al ., 2022b).…”