The chytrid fungus is a modern-day scourge of toads, salamanders and frogs around the globe, one of the greatest conservation threats amphibians face. As a waterborne pathogen, the fungus's highly infectious life stage called a zoospore infects amphibian skin, then multiplies. As the disease infects more and more skin cells, the infected animals lose the ability to remain well hydrated and to regulate temperature. Eventually, they lose the ability to breathe. Some species are resistant to infection; in others, the death toll in a local population can reach 100 percent. While the total number of affected species is unknown, global studies show the fungus is a major factor in the global decline and extinction of amphibian species, with roughly a third of these species threatened throughout the world.
Dr Tracie Seimon, a molecular scientist with WCS's Wildlife Health Programs has led a team with a specialized mobile laboratory in places as diverse as to Rwanda, Peru, Myanmar and Uganda, to name a few, to test amphibians for disease-causing microorganisms. With this testing, the team has documented the fungus (and potentially disease outbreaks and species decline) in Peru's Cordillera Vilcanota, the highest elevation where frogs are known to exist. They have also mapped chytrid distribution, in the absence of noted die-offs, across the Albertine Rift in Africa.
These results create a better overall view of the range of effects and impact of chytrid fungus within landscapes and across species. In time, our work may guide treatment plans by directing resources to locations where infection most commonly leads to disease or threatens endangered species.
Banner photo of amphibian in Peruvian highlands credit: Tracie Seimon, WCS
Thumbnail photo of Albertine Rift amphibian credit: A.J. Plumbtre, WCS