Scientists in the United States took samples from bullfrogs shipped to Asian markets in seven different cities. Of the frogs sampled, 41 percent were found to be infected with the chytrid fungus. Most of the bullfrogs shipped into the United States came from Ecuador, Brazil and Taiwan, all countries with warmer and more humid climates than most of North America.
The same team of scientist took samples in Brazil, both at frog farms and in wild populations in the Atlantic Forest. The chytrid fungus had indeed mutated into four different strains of Batrachochytrium dendrobatidis. One of those strains was a perfect match for samples taken from a bullfrog in Michigan, originally shipped from the Atlantic Forest area. A comparison between biological samples taken in both Brazil and Japan showed that the chytrid fungus had already crossed the Pacific Ocean.
It is theorized that the live trade of these frogs has already introduced the chytrid fungus on a global scale. Curtailing this practice may not eliminate the fungus from areas already infected, but it may help contain the chytrid within those areas. Global warming and the expected increase in average temperatures worldwide will most likely make it harder to contain this highly adaptable organism.