Experiments Reveal Cross-Class Transmission of Ranaviruses

By Jeff Schaeffer | AFS Co-Chief Science Editor. E-mail: [email protected]

WINNER: 2014 Best Paper, Journal of Aquatic Animal Health

Viruses are a source of mortality in lower vertebrates, and often threaten both cultured and wild populations. However, their epidemiology is not well understood, especially when it comes to the issue of infection reservoirs. Roberto Brenes of Carroll University and his colleagues examined interclass transmission of ranaviruses by challenging five fish species and three turtle species with viruses isolated from an infected Pallid Sturgeon Scaphirhynchus albus, eastern box turtle Terrapene carolina carolina, or American bullfrog Lithobates catesbeianus to better understand this issue. Cross-class transmission did occur, and resulted in low (<10%) mortality and infection rates. Mortality was likely severe enough to be a factor in aquaculture, and both fish-to-turtle and turtle-to-fish transmission occurred. Their results suggest that either class could serve as a virus reservoir and contribute to pathogen pollution if infected individuals are transported to new environments. Preventing virus transport in host/reservoir species is likely to be an important conservation strategy, especially in areas susceptible to outbreaks.

REFERENCE

Brenes, R., D. L. Miller, T. B. Waltzek, R. P. Wilkes, J. L. Tucker, J. C. Chaney, R. H. Hardman, M. D. Brand, R. R. Huether, and M. J. Gray. 2014. Susceptibility of fish and turtles to three ranaviruses isolated from different ectothermic vertebrate classes. Journal of Aquatic Animal Health 26(2):118-126. dx.doi.org/10.1080/08997659.2014.886637

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