Scientists who track flu fear new, powerful strains

January 18, 2000
Web posted at: 7:45 a.m. EST (1245 GMT)

In this story: Influenza has deadly history Researchers track global movement RELATED STORIES, SITES

From staff reports

ATLANTA (CNN) -- As the United States and Europe battle yet another cold and flu season, scientists are having more trouble tracking and predicting where and when the next strain will pop up.

FOCUS The Path of the Flu     RESOURCES CDC Influenza Home Page World Health Organization: Influenza     ALSO    VIDEO CNN's Holly Firfer looks at where the flu comes from and how easily it travels across the globe. Real 28K 80K Windows Media 28K 80K

As global travel becomes easier, the highly contagious virus can now hitch a quick ride to any part of the world at any time of the year, disrupting what has been a predictable pattern.

"We are very worried we will have a worldwide pandemic of influenza that will affect probably 40 percent of the world's population," said Dr. Steven Mostow of the University of Colorado. Mostow said the number of people killed from such a wave of influenza could rival some of the worst outbreaks in modern times.

Influenza has deadly history

"We will never be able to control the flu like we control polio, like we control smallpox," said Mostow. "Because the flu virus isn't stable. It mutates. And it is smarter than we are."

Researchers at the U.S. Centers for Disease Control and Prevention and the World Health Organization track movement and mutations of each flu outbreak as they travel around the globe. They do this to help them decide which strains to attack with each year's flu vaccine.

Researchers track global movement

The flu commonly moves from China east across Asia to Alaska, where it works its way south into the heart of North America.

"It then mutates and moves through the U.S. over a several-week period," said Mostow, "jumps the Atlantic and goes into western Europe, England, France and Germany, Switzerland, et cetera."

In June, July and August, flu trackers monitor strains that are then usually circulating in the Earth's Southern Hemisphere.

"It jumps below the equator, showing up in Africa, South America, Australia and New Zealand," Mostow said.

A new parent strain of influenza has emerged about every 100 years, according to experts. The current troublemaker, known as the Sydney virus, is a mutation of its parent strain, the notorious Hong Kong flu, which claimed so many victims 30 years ago.

"The problem is," said the CDC's Dr. Nancy Cox, "we can't predict when it will occur. As one of my colleagues said, the influenza clock is ticking, but we don't know what time it is."

Health Correspondent Holly Firfer contributed to this report.