Ranavirus in Costa RicaJake Kerby, Ph.D. (@ecologyprof)

University of South Dakota

#RV13

Acknowledgements

Funding:

US Fish and Wildlife Service- Wildlife Without Borders

NSF- Major Research Instrumentation Grant

Rufford Grant

Authors:

Steven Whitfield, Erica Geerdes: USD

Dr. Adrian Pinto, Iria Chacon, Erick BallesteroRodriguez: Universidad de Costa Rica

Randall Jimenez: National Univ of Costa Rica

Mo Donnelly: Florida International University

Background

Amphibian decline story: Chytrid?

Central America hosts a diverse, unique, and highly threatened amphibian fauna, yet there has been little effort to describe presence, systematics, host range, or impacts to hosts or populations of impacts to hosts or populations of Ranaviruses.

One paper of interest- Whitfield declines in both reptiles and amphibians

Sought out to examine disease presence in both

Whitfield S M et al. PNAS 2007;104:8352-8356

Amphibian disease

The story of chytrid in Costa Rica is well documented,

but what about Ranavirus?

One study done by Angela Picco did not find evidence

of infection (Picco and Collins 2007).

Rick Speare mentions a “possible iridovirus” in Cane Rick Speare mentions a “possible iridovirus” in Cane

toads in 1991.

Might Ranavirus be present?

Initial surveys

Did initial work on 12 species with sampling only at La

Selva Biological Field Station. Found ranavirus present

in four individuals of the species, Craugastor bransfordii.

Published in Herpetological Review (Whitfield et al. Published in Herpetological Review (Whitfield et al.

2012).

Co-infection

We did a more thorough study expanding the surveys to 20 species at the same site. We examined species for infections of both ranavirus and Bd.

Found several species were co-infected. (Whitfield et al. 2013). First to document (Whitfield et al. 2013). First to document association of ranavirus and Bd infection in a single species: Craugastor fitzingeri.

Overall, 42 individuals from 9 species were found with ranavirus. (16.6%)

No clinical signs of disease though.

Where is it from?

One key question is to better understand where this

ranavirus strain emerged from.

We sequenced the initial strain and found it to match a

North American isolate.

Was it introduced from N. America? How? When?Was it introduced from N. America? How? When?

Unintuitive trade

Shops in Costa Rica illegally sell

Xenopus laevis smuggled in from the

states.

We obtained animals that were We obtained animals that were

confiscated at the Costa Rica airport

and found them to be infected with

ranavirus!

Still need to sequence DNA from these

samples.

Unintuitive trade

Other trade species: Newts,

Fire bellied toads…

Given previous work in US

on bait trade influence of on bait trade influence of

infection, this might be a

serious but overlooked

problem.

More work desperately

needed.

Current work

We are currently working to isolate a Costa Rican

strain of ranavirus from wild populations, from pet

trade, and from introduced populations of Puerto

Rican Coquis.

Examining presence of ranavirus in same populations

and in museum samples dating back to 70s.

Would like to better understand if the pathogen is

responsible for amphibian declines in the country.

Relict Sites

Expanded the search to across the country

Currently are analyzing samples from 10 sites that have

persisted through previous die offs. Examining both

RV and Bd.RV and Bd.

Other Ranavirus work

Currently, I have a PhD student examining Ranavirus infection in South Dakota/Nebraska

Drew detected an outbreak in Spea

bombifrans. Currently being isolated bombifrans. Currently being isolated in Jesse Brunner’s laboratory.

We just received funding to examine the impacts of agricultural inputs on salamanders in South Dakota.

@drewrdavis- follow for latest updates!

Questions?