Multi-year Occurrence of Ranavirus and Batrachochytrium dendrobatidis in Anurans from Central, Southeast, and Coastal Regions of Texas, USA, 2012-19.

Ranaviruses (Iridoviridae) and chytrid fungus (Batrachochytrium spp.) cause globally reportable diseases affecting a wide array of amphibians. Both pathogens are well documented in the US and have caused local or regional scale mortality events for susceptible amphibians. Over a period of 8 y (2012-2019), we tested salvaged amphibians collected during amphibian audio survey work across the central, southeastern, and coastal areas of Texas, US. Individuals of 7/8 anuran taxa tested positive for either or both pathogens, as did individuals in counties with large sample sizes (i.e., n>25) across taxa. Ranavirus prevalence was high in 2012 (67%) but decreased to 5% by 2019. Conversely, chytrid fungus prevalence started low in 2013 (4%) but increased to 20% by 2019. The detection of both pathogens in any individual was consistently rare throughout the period. Although salvage of specimens during annual fieldwork adds permitting requirements, handling time, and curation effort, we argue that this additional effort significantly contributes to regional pathogen surveillance. Therefore, it should be considered a standard approach for the extensive array of roadway-based herpetofaunal surveys conducted each year.