Ranavirus identified in frog cadavers from the Dwingelderveld die-off in 2010

Press release: 28-02-11

Photo: Dick Willems

Researchers at the Dutch Wildlife Health Centre (DWHC) at the University of Utrecht Vet School report the first identified case of ranavirus in wild frogs in the Netherlands.
In September 2010 this virus caused the death of thousands of frogs in a small lake at the Dwingelderveld National Park. The dead frogs were found by a volunteer from RAVON (the Dutch Organisation for Reptile, Amphibian and Fish Research) and submitted to the DWHC for post-mortem investigation which showed evidence of a possible virus infection, later identified as ranavirus by further testing (PCR) carried out at the veterinary school in Gent (PCR) and TiHo Hannover (EM). This virus is not infectious for humans.

First case to be identified in the Netherlands

According to Marja Kik, pathologist at the DWHC, the Dutch Wildlife Research Institute: “Mass die-offs caused by ranavirus infections can occur in reptiles, amphibians and fish. Ranaviruses are highly infectious and represent a significant threat to these creatures, particularly to rare and protected species. As tests for ranavirus are not routinely performed on amphibian/reptile/fish wildlife cadavers it is not known how long the viruses have been present in the Netherlands or where else in the country they may occur”.

Limiting the spread

Photo: Dick Willems

Annemarieke Spitzen, a researcher at RAVON says: “The discovery of this virus in the Netherlands can be attributed to the attentive park rangers and RAVON volunteers. We still do not know how the virus entered the country or whether it has infected other lakes in the park”. The DWHC and RAVON have advised representatives of Natuurmonumenten as to how they can limit the spread of the virus from the area that is known to be affected.

Dutch Wildlife Health Centre (www.dwhc-dev.wp.hum.uu.nl)

The DWHC advises stakeholders including local and national authorities in the making of guidelines relating to animal (wild and domestic) and public health. The DWHC performs post-mortem investigations, runs large-scale monitoring and disease surveillance programs and provides information and training in these areas.

RAVON (www.ravon.nl)

RAVON is active in the conservation of reptiles,amphibians and fish and provides information and advice about these animals in the Netherlands. RAVON coordinates two national monitoring networks and performs research into protected species, their habitats and distribution.