Lips has studied the issue since the early 1990s, becoming a recognized expert on the subject. She, along with her graduate and doctoral students, regularly visit the high jungles of Central America, roughing it in the wild while collecting data on the ecological systems before, during and after the fungus arrives. This latest study, conducted with Sears, an assistant professor of zoology at SIUC, and two other colleagues at the Illinois Natural History Survey and Zoo Atlanta, expands upon that work by seeking better understanding of the spread of the fungus, its triggers and how it might be spread. Specifically, the researchers examined data from South American amphibian declines to see whether the wave-like spread seen in Central America, typical of an emerging infectious disease, was evident. One previous theory, for instance, blamed the fungus on global climate change. Lips and Sears, however, found climate change doesn’t appear to trigger outbreaks of the fungus, but that it instead spreads in wave-like patterns often seen in exotic species and emerging infectious diseases. They call their theory the “spreading pathogen hypothesis.”
Using modeling, the researchers found evidence of four different introductions of Bd into South America. They found that the fungus spread through the population at a rate similar to that seen in Central America and in a manner that best explains amphibian population declines in Central and South America. “What makes the study really relevant is we can now generalize how the fungus is spread,” Lips said. “We know from our research, that if we start looking in the right time and place in an area where the fungus is, we’re probably going to see it affecting frog populations. This helps us understand what’s going on, and it can potentially help us get out in front of it.” The study could help governments and environmental agencies focus on ways to prevent the fungus’ spread through more regulation of potential infection routes, such as the ornamental plant and aquarium wildlife trade. The fungus can easily hitch a ride to other regions through such trade, Lips said.
“If you go and buy an ornamental plant from one of these regions and plant it in your yard, or you buy a frog at a pet shop, think about it. If the fungus is there and still alive, it’s now introduced into the environment. Then it can get into your pond or streams.” Lips said simple testing of such products and organisms before importing them could reveal the fungus’ presence. Once discovered, simple anti-fungal drugs will kill the fungus before it can contaminate an area. “Our research has shown that once the fungus gets somewhere new it spreads like wildfire,” Lips said. “So the key is preventing it from spreading.” The fungus is present in North America, including Illinois, but little is known so far about its impact here.
Science Daily
April 15, 2008
Original web page at Science Daily
