Collapse of Amphibian Communities Due to an Introduced Ranavirus

The emergence of infectious diseases with a broad host range can have a dramatic impact on entire communities and has become one of the main threats to biodiversity [1–4]. Here, we report the simultaneous exploitation of entire communities of potential hosts with associated severe declines following invasion by a novel viral pathogen. We found two phylogenetically related, highly virulent viruses (genus Ranavirus, family Iridoviridae) causing mass mortality in multiple, diverse amphibian hosts in northern Spain, as well as a third, relatively avirulent virus. We document host declines in multiple species at multiple sites in the region. Our work reveals a group of pathogens that seem to have preexisting capacity to infect and evade immunity in multiple diverse and novel hosts, and that are exerting massive impacts on host communities. This report provides an exceptional record of host population trends being tracked in real time following emergence of a wildlife disease and a striking example of a novel, generalist pathogen repeatedly crossing the species barrier with catastrophic consequences at the level of host communities. [Display omitted] •Amphibian communities in a national park have suffered outbreaks of severe disease•Diverse host species have experienced mass mortality and population collapse•Disease emergence is the result of the introduction of a single viral strain•CMTV-like ranaviruses are virulent pathogens with an extremely broad host range Emerging infectious diseases pose a major threat to biodiversity and human health. Price et al. show that an introduced virus has been responsible for severe disease and declines among amphibian communities in Spain via its capacity to simultaneously exploit extremely divergent hosts.