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Researchers Try to Squelch Spread of Avian Flu

Goal Is to Keep Virus From Infecting People

By Susan Levine
Washington Post Staff Writer
Sunday, February 13, 2005; Page C04

Daniel Perez is in a race. Against time -- and an especially lethal virus.

In a low-slung, antiseptic-looking building in College Park, the University of Maryland scientist is working with a small cadre of researchers to try to avert what they worry could one day be a script for a real-life horror story. Assisting them is a small flock of chickens and quail.


Daniel Perez, with Erin Sorrell, said researchers want to determine how the disease-causing organism replicates so they don't have to "kill all the chickens." (Kevin Clark -- The Washington Post)

Their focus is avian influenza, a scourge that worldwide has caused hundreds of millions of dollars in losses of infected, or merely exposed, poultry -- a figure that experts say pales beside the potential risk to people.

There already have been ample cases, mostly in Asia, establishing the dire threat when humans contract the virus from birds. "It's scary," Perez said. "Most of them die."

The researchers' race is to figure out how the microorganism replicates before it mutates enough to be transmitted easily within a family, a community or more.

"The biggest question is, what is it going to take for this virus to gain the ability to go from human to human?" Perez asked. He acknowledged: "There are many things that are out there that we don't know."

The pandemic against which infectious diseases usually are measured is the 1918-19 Spanish flu outbreak, which claimed the lives of 20 million to 50 million people worldwide. Yet in the instances in which avian influenza has been diagnosed in people, it has proven even more virulent -- killing 32 of 44 victims in 2004, most of them otherwise healthy children and young adults.

Symptoms start in the usual flulike way. Then the virus ramps up, with the body's immune system fighting so much and so hard that it begins breaking down.

The University of Maryland is the lead institution in a new national project to prevent and control avian influenza. University officials say a $5 million grant it recently received from the U.S. Agriculture Department is the largest the agency has awarded for the study of a single animal disease or health threat. Researchers and extension specialists in 17 states are involved in the effort.

Perez, an assistant professor of virology and leading avian influenza researcher, is directing the project. He likens the job ahead to detective work -- though it will be sleuthing in a laboratory, clad in face masks and shields, special gloves and suits, as genetic material is studied, manipulated, injected into the birds and studied anew.

They do not expect to eradicate avian influenza. Its natural hosts are aquatic fowl, ducks, geese and other often migratory birds that tolerate the virus intestinally with little ill effect, secreting it through fecal waste into ponds, lakes and rivers.

It becomes deadly when it moves into birds that live on land, particularly chickens. (Quail play a role as intermediate hosts.) Humans can become sick by handling infected live poultry or contaminated meat.

"Right now the best solution we have is to go and kill all the chickens," Perez said. In one Virginia episode, such widespread extermination totaled several million birds and nearly $100 million. "That's not much of a tool," he said.

In the several laboratories that house the work of Perez and his colleagues -- a group that includes research fellows from Colombia, Israel, Bangladesh, China and the Philippines -- they are taking the virus, which they already have adapted to quail, and forcing further genetic changes that they will study in chickens.

"On our side, we hope to understand a little bit more what the virus takes to replicate," Perez explained.

In other project locations, researchers will attempt viral sampling of wild birds as they migrate along four major flyways, and in still others, scientists will concentrate on public education.

If what is learned prevents even one major outbreak of avian influenza in this country, Perez said, the grant will have more than paid for itself.

The ultimate goal, however, is to prevent what a diamond-shaped sign on one of his laboratory doors has been amended to announce.

It originally read, "CHICKEN CROSSING."

It now reads, "CHICKEN flu CROSSING to humans."


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