Finches hold link to infectious disease ecology

Ithaca, N.Y.-An eye disease that struck eastern house finchesin Maryland in 1994 may help expand scientists' understanding of a numberof epidemic diseases in humans, animals and plants.

A project to investigate how the finch epidemic may shed light on theecology of infectious disease is under way. It is being funded by a five-yeargrant from the National Institutes of Health. This study and related projectswill examine how environmental changes such as habitat destruction, globalwarming and pollution may cause diseases to emerge.

"An unusually large number of new diseases have emerged in the last20 years or so, not only in humans, but in animals and plants as well,"says ecologist Andre Dhondt of the Cornell Laboratory of Ornithology inIthaca.

He cites as examples AIDS, ebola, drug-resistant tuberculosis, mad cowdisease, and other spreading plagues.

"This is probably the first study ever where it has been possibleto study in great detail a newly emerging disease in a natural population,"Dhondt says.

In the case of the finches, scientists at the University of Georgia andNorth Carolina State found the birds were infected with a new strain ofMycoplasma gallisepticum, a bacterium that is a common cause of upper respiratoryinfections in chickens. It had never been seen in songbirds.

"The goal is not to know about house finches and Mycoplasma,"Dhondt says. "The goal is to develop a mathematical model that allowsus to identify what we need to measure and summarize what we've found."

The model can then be applied to other diseases.

"One of the interesting things about Mycoplasma in house finchesis that it has many similarities to AIDS," Dhondt says. "Understandinghow we can fight this disease in finches might help us understand how totreat similar epidemics in humans."

The finch infection reduced the eastern house finch population by 60percent - 180 million birds - within 2 1/2 years.