Missouri ponds hold clues for frog disease
Key new research carried out in the US state of Missouri, has offered clues on chytrid fungus, which is responsible for sickening and killing amphibians all over the world.
Scientists carrying out research in Missouri ponds found that not only did the fungus not reside in all ponds, but it was possible to distinguish between infected and non-infected ponds.
Furthermore, researchers believe that the fungus, which was thought to be specific to amphibians, could also be lurking in invertebrates, such as insects.
The effects of the fungus, Batrachochytrium dendrobatidis (Bd), which is also known as amphibian chytrid, were first seen in 1993 when dead or dying frogs began turning up in Queensland, Australia.
Since then the fungus, which infects the skin that amphibians use to breathe and absorb water, has sickened and killed frogs, toads, salamanders and other species, driving hundreds to extinction, according to researchers.
Having studied Bd in South Africa, lead researcher Kevin Smith, from Washington University in St. Louis, began collecting tadpoles from Missouri ponds, where the disease in endemic, and testing their mouth parts under a microscope.
Finding fungus in only a third of the ponds whose tadpoles he tested, Dr Smith decided to investigate more widely and study the entire pond ecosystem.
Along with then-undergraduate Alex Strauss, Dr Smith surveyed the species living in 29 ponds in east-central Missouri. The patterns found in Bd infection could be an indirect effect of variations in the invertebrate communities, according to Dr Smith.
"Alternative hosts and reservoirs have been a key missing piece in our understanding of chytrid epidemiology," he said. "The fungus, like any pathogen, cannot be effectively controlled unless all its hiding places are known."
It is hoped that research in areas where chytrid is endemic could be put to use in areas where it is epidemic. The full study has been published in the September 25 edition of PLOS ONE journal.
With Strangles Awareness Week just around the corner (5-11 May), vets are being encouraged to share a survey about the disease with their horse-owning clients.
