for National Geographic News
An antibiotic primarily used to treat pinkeye in humans rids frogs of the fungal disease that is wiping out amphibian populations around the world, a team of New Zealand scientists reports.
Infected frogs treated with the drug for two weeks were cured of the deadly disease, called chytridiomycosis or frog chytrid disease.
"Our results are 100 percent certain," said Phil Bishop, a zoologist at the University of Otago in Dunedin, New Zealand.
The fungal disease, along with habitat destruction and global warming, is blamed for putting more than a third of the world's 6,234 known amphibian species on the path to extinction.
At least 130 species are most likely already gone, according to the Global Amphibian Assessment. (Related: "'Frog Hotel' to Shelter Panama Species From Lethal Fungus" [November 2, 2006].)
Scientists have been racing to find a way to curb the disease before it takes an even heavier toll. The antibiotic chloramphenicol is "definitely the best" treatment found to date, Bishop said.
Another drug, itraconazole—which is used to treat fungal and yeast infections in humans—has also been shown to cure chytrid disease. But the drug causes kidney damage in some frogs, he noted.
Itraconazole also remains under patent protection and is therefore expensive, whereas chloramphenicol is generic and widely available.
Allan Pessier is a veterinary pathologist at the San Diego Zoological Society in California and an expert on the deadly fungal disease. He said more tests are needed before declaring one drug better.
Both drugs, he added, are effective treatments for captive frogs but are probably never going to see widespread use in the wild as a spray or liquid dumped into streams and ponds.
"It's a step that helps us manage the disease, but it's not like declines associated with chytridiomycosis are going to go away because of this discovery," he said.
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