Survey of Ranavirus in Amphibians and Reptiles of Colombia

Ranaviruses are emerging pathogens of ectothermic vertebrates that have been linked to mass mortality events globally in amphibians, reptiles, and fishes. In South America, ranavirus has been identified in multiple countries, but its distribution, host range, and epidemiology remain poorly characterized relative to other continents. Most infections have been documented in amphibians, particularly the invasive Aquarana catesbeiana, although detections have also included native species across Brazil, Chile, Argentina, Venezuela, Ecuador, Peru, and Colombia. To date, no studies have surveyed wild reptiles for ranavirus infection in South America, despite reptile mortality events linked to this virus in other regions. Here, we surveyed ranavirus in amphibians and reptiles of Colombia using quantitative polymerase chain reaction (qPCR) with genomic DNA extracted from toe and tail tips. We did not detect ranavirus in reptiles from the departments of Nariño (n = 30) or Atlántico (n = 30). We report the first detection of ranavirus in the striped robber frog (Pristimantis unistrigatus) in Nariño in southern Colombia, with a prevalence of 26.7% (8 of 30). Ranavirus was not present in amphibians from a lowland site in Atlántico on the northern Caribbean coast (n = 30). This study expands the known geographic and host range of ranavirus in Colombia and is the first to survey reptiles in South America. The lack of ranavirus detection in reptiles is notable but does not preclude the possibility of infection, as sample sizes, study sites, and temporal coverage were limited. Our findings highlight the potential role of direct-developing frogs of the genus Pristimantis as valuable sentinels for pathogen monitoring, given their high species diversity, local abundance, and wide elevational distribution. Previous surveys have demonstrated low-level but geographically broad ranavirus prevalence in other Pristimantis species across the Andes, though sampling has often been haphazard and limited by small sample sizes. Given the growing threats to amphibian and reptile species in Colombia, further research is needed to assess the full scope of ranavirus dynamics. We recommend integrating pathogen surveillance into ongoing ecological and conservation programs, especially in biodiverse regions where invasive species and anthropogenic pressures may amplify disease emergence.