Ranaviruses in North America: A Brief Review in Wild Herpetofauna

Abstract

Ranaviruses are globally emerging pathogens of poikilothermic vertebrates. They affect over 40 species of amphibians in the USA and at least nine species in Canada. Additionally, ranaviruses have been found in at least eight species of reptiles in the USA and two species in Canada. Several of the species that are known to be affected are listed by state or federal agencies as they are of conservation concern (e.g., Cryptobranchus alleganiensis alleganiensis and Terrapene carolina carolina). In this brief review, we discuss the diversity and distribution, the species affected, the clinical signs of ranavirus disease (ranavirosis) that one would see in the field, morbidity and mortality events and their likely triggers, and conservation implications from the emergence of ranaviruses in populations of North American herpetofauna. We also would like to stress that ranaviruses are reportable infections in amphibians (according to the OIE, World Health Organization for Animals) and if an infection is suspected, the incident should be reported the proper authorities. Additionally, biosecurity measures should be taken to avoid the spread of ranaviruses between individuals and between field sites.