Scientists Use Computer Model to Predict U.S. Bird Flu Outbreak

If the avian flu (search) leads to a worldwide outbreak in which humans begin contracting the disease not from poultry, but from each other, how would the United States cope?

That's the question scientists from Johns Hopkins University (search) and Imperial College (search) in London are asking as they imagine a worst-case scenario in which Americans unwittingly start spreading the disease at an alarming rate.

The scientists are using a computer model they had earlier created to predict a similar epidemic in Thailand, where the avian flu has been prevalent, said Derek Cummings, research associate at the Bloomberg School of Public Health at Johns Hopkins.

But the American model looks into what happens after the disease arrives, rather than simply exploring how to contain a small community where it may surface first, Cummings said.

The avian flu strain that looks to be the most likely candidate to cause an outbreak — H5N1 — has not emerged on American soil, he said.

"We're approaching this from the angle that there would be cases globally and asking how mortality might be minimized: What can you do to sort of deal with the incidents so that it doesn't hit all at once?" Cummings said. That would allow time for vaccines to be developed, he said.

Funded by the National Institute of General Medical Sciences, a branch of the National Institutes of Health, the scientists are using U.S. Census Bureau data and making a number of assumptions about U.S. population density, Americans' travel and work habits and the kind of human interactions that might most easily spread the disease.

"We are trying to get a handle on how far people move spatially in a given day, which would give you an idea of how fast the disease moves," Cummings said. "And the model also considers domestic air travel and how that spreads disease and what kind of controls could be put in place."

The scientists are also making educated guesses about the possible impact of "social distancing measures" — such as staying home from school when a child is sick.

Cummings said the team is considering how American access to avian flu vaccines might serve as extra protection. The U.S. Department of Health and Human Services recently entered into agreements with three pharmaceutical companies to manufacture vaccines meant to specifically fight the avian flu. The University of Maryland Medical Center in Baltimore is one of three universities testing the first avian flu vaccine produced by sanofi pasteur. The University of Maryland Center is completing the first phase of a trial involving 154 Maryland volunteers on Oct. 31.

Cummings said he and his collaborators plan to release details of their American pandemic model in November.

The Capital News Service contributed to this report.