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Researchers Discover Why Bird Flu So Deadly

An international team of researchers says it has discovered what makes the bird flu virus so deadly. It appears the disease affects a wide range of organs other than the lungs in adults and is capable of killing the fetus of pregnant women. VOA's Jessica Berman reports.

Scientists believe the H5N1 virus that is responsible for the bird flu poses one of the most potentially serious public health threats of all time. Since 2003, of the 277 people in 10 countries who have contracted the avian influenza virus, 60 percent have died.

Researchers have been trying to develop vaccines against the avian flu to prevent the illness, as well as treatment for infected individuals.

However, little has been known about exactly what H5N1 does to the human body, according to Ian Lipkin, professor of neurology and pathology at the Columbia University in New York.

Lipkin is senior collaborator on a paper by international researchers who studied the bodies of two individuals who had died of the avian flu. He says the avian flu affects primarily the lungs, causing a surprising amount of damage.

But in addition to the lungs, Lipkin says, investigators found H5N1 had spread to the gastrointestinal tract, and the infection was also discovered in the brain and in the reproductive tract.

"In one of these individuals who died of this infection the virus was also found in the placenta and in the fetus," he said. "So, it has the capacity to infect unborn children."

Lipkin says it appears the severe and widespread damage to the body inflicted by the virus H5N1 may be caused by the body's immune system going into overdrive - a phenomenon that some call a "cytokine storm."

In a way, Lipkin says that could be good news for the development of a treatment.

"We may be able to find ways to restrict damage, to control damage, to better manage people clinically not only by focusing on the virus itself, but also on some of the immunological manifestations of infection," he said.

The study looking at the health impact of the avian flu virus was published in the international medical journal, The Lancet.