Detection of Ophidiomyces ophidiicola in Samples from Free-Ranging Snakes in Germany, 2021-22

Ophidiomyces ophidiicola (Oo) is a fungus primarily affecting the skin of a wide range of snake species. Ophidiomyces ophidiicola has been found in snakes under human care as well as in free-ranging snakes, and the number of documented infections in free-ranging snakes from Europe is increasing. To better understand the distribution of Oo in snakes in Germany, 329 samples were collected from 328 free-ranging snakes from 47 different locations in Germany in 2021-22. Samples included swabs (n=188), shed skins (n=134), and carcasses (n=7) from six different species: 140 dice snakes (Natrix tessellata), 68 European common adders (Vipera berus), 62 Aesculapian snakes (Zamenis longissimus), 29 smooth snakes (Coronella austriaca), 17 whip snakes (Hierophis viridiflavus), and 12 grass snakes (Natrix natrix). Sampled animals were examined for the presence of skin lesions and samples were screened for Oo by real-time PCR (qPCR). Ophidiomyces ophidiicola was detected in 30/328 snakes (9.1%), including dice snakes (23/30, 77%), Aesculapian snakes (5/30, 17%), and grass snakes (2/30, 7%). No differences were found in the likelihood of detection of Oo between individual colubrid species, but colubrid snakes were significantly more likely to be Oo positive than were viperid snakes (Fisher's exact test, P=0.001). Skin lesions were observed in 37/328 snakes (11.3%), of which 8/37 (22%) were Oo positive by qPCR. Significant differences were found in Oo prevalences depending on the presence of skin lesions, and Oo positive snakes were more likely to have skin lesions compared to snakes that were Oo negative (OR=3.37 [95% confidence interval 1.38-8.26%; P<0.05]).