For the first time, a deadly fungus that has ravaged amphibians and impacts more than 700 species has been cured in a wild population.
So say the results of a five-year study, just published in the journal Biology Letters, highlighting the removal of the fatal chytrid (amphibian chytridiomycosis) fungus from a population of Mallorcan midwife toads (Alytes muletensis) on their native island of Mallorca, Spain.
The researchers -- from the Zoological Society of London, the National Museum of Natural History in Spain (MNCN-CSIC), and Imperial College London -- collected tadpoles of the toad from ponds on Mallorca that were affected by chytridiomycosis and brought them to a laboratory, where they were treated daily with a bath of tapwater mixed with the antifungal agent itraconazole.
The scientists then returned the tadpoles to the affected ponds, which were treated with the lab disinfectant Virkon S, "liberally applied to all rock, gravel, crevice and vegetated areas that surrounded the immediate environs of each breeding site," according to the study.
(The researchers acknowledged in their study that Virkon S is "a controversial chemical to use environmentally," noting their choice to use it was "driven by the urgency of midwife decline on Mallorca.")
Samples taken from the pond sites up to two years after the treatment showed no evidence of the chytrid fungus in the on-site population.
"This is the first time that chytrid has ever been successfully eliminated from a wild population, a real positive which we can take forward into further research to tackle this deadly disease," said Jaime Bosch, a senior researcher at MNCN-CSIC, in a statement.
Chytrid fungus has driven global declines and extinctions in amphibious populations worldwide. "This study represents a major breakthrough in the fight against this highly-destructive pathogen," said study co-author Trenton Garner, of the Zoological Society of London.