Design and Analysis of Ranavirus Studies: Surveillance and Assessing Risk

Ranavirus Ecology and Evolution: From Epidemiology to Extinction

“…Price et al ( 2014 ) recently reported declines in amphibian communities at multiple sites in Spain after the apparent introduction of a novel ranavirus. There are, however, several reports of ranavirus being present in larval and post-metamorphic amphibians without notable disease or mortality (Duffus et al 2015 ), although most studies do not collect longitudinal data and are liable to miss mortality events (Gray et al 2015 ). It is worth noting that sublethal infections by ranavirus can impact fi tness-related traits such as growth and development (Echaubard et al 2010 ).…”

“…One problem is a lack of longitudinal data. That is, studies that track the incidence of ranavirus infection and mortality over time are rare (Gray et al 2015 ). A focus on collecting the data that could be used to parameterize epidemiological models would signifi cantly advance our understanding of ranavirus ecology (Gray et al 2015 ).…”

“…What makes these virus-host community interactions different from others that have not suffered declines remains unknown. Clearly, there is a need for more studies of the population-level effects of ranavirus outbreaks, particularly long-term studies of sites with reoccurring ranavirus die-offs (Gray et al 2015 ).…”

“…LMBV is also commonly found in the absence of morbidity or mortality (Hanson et al 2001 ;Grizzle and Brunner 2003 ;Groocock et al 2008 ;Southard et al 2009 ). It is thus important to collect both epidemiological and demographic data on host populations at multiple time points to understand the effects of ranaviruses on their host populations (Gray et al 2015 ).…”

Distribution and Host Range of Ranaviruses

“…Ranaviruses are known to infect at least 175 species across 52 families of ectothermic vertebrates, and are found on all continents but Antarctica (Table 1 ; Figs. 1 about the epidemiology, geography, and host range of ranaviruses comes from investigations of obvious die-offs, sporadic surveillance efforts in small numbers of populations at one or two time points, and a few larger-scale surveillance efforts focused on a handful of species of economic importance or conservation interest (Grizzle and Brunner 2003 ;Gray et al 2009b ;Whittington et al 2010 ;Miller et al 2011 ;Gray et al 2015 ). Because gross signs of infection may not be displayed, many host species are cryptic and diffi cult to detect, the lack of awareness of ranaviruses as significant pathogens, and occasional misdiagnosis, the known geographic distribution and host range of ranaviruses are likely underestimated.…”