bird flu no. 1 health threat in world, cdc chief w

Tuesday, February 22, 2005

Bird flu No. 1 health threat in world, CDC chief warns


Dr. Julie Gerberding is director of the CDC.

WASHINGTON — Avian flu poses the single biggest health threat to the world right now, and health officials may not yet have all the tools they need to fight it, the head of the Centers for Disease Control and Prevention (CDC) said yesterday.

"This is a very ominous situation for the globe," CDC Director Dr. Julie Gerberding told a meeting of the American Association for the Advancement of Science. Scientists expect that the virus, which has swept through poultry in Asia, will mutate to become as deadly and infectious as the flu viruses that killed millions of people during three pandemics of the 20th century.

Gerberding became the latest public-health official to sound the alarm over bird flu. World Health Organization officials have predicted that if the virus develops into a form capable of spreading among humans, in the most optimistic scenario 2 million to 7 million people would die worldwide, and the toll could potentially reach 100 million.

The 1918 pandemic killed 20 million to 40 million people worldwide, including more than 500,000 in the United States.

In 1957, a pandemic caused 70,000 deaths in the United States, and the 1968 pandemic killed 34,000.

Vaccine efforts are still focused on garden-variety influenza, which kills 36,000 Americans every year, and it would be impossible, in case of an avian-flu epidemic, to switch gears quickly to make a special avian-flu vaccine, Gerberding said.

In Asia, there already have been a number of deaths among people who caught the flu from chickens or ducks. The mortality rate is very high — about 72 percent of identified patients, Gerberding said. There also have been documented cases of this strain of flu being transferred from person to person, but the outbreak was not sustained, she said.

"We are expecting more human cases over the next few weeks because this is high season for avian influenza in that part of the world," Gerberding said. Although cases of human-to-human transmission have been rare, "our assessment is that this is a very high threat. ... You may see the emergence of a new strain to which the human population has no immunity."

The CDC chief said her agency is getting ready for a possible pandemic next year. A special flu team, organized last year, continues to monitor the spread of the avian flu and to analyze the strains as they appear.

The government has ordered 2 million doses of vaccine that would protect against the known strains of avian flu. Gerberding said this would give manufacturers a head start on making the shots that would be needed to combat a U.S. epidemic.

But at the same time, the agency is helping to produce the 180 million or so doses of regular flu shots needed annually. Gerberding said the timeline for producing the regular vaccine yearly is very tight, with little room for problems. To produce a new vaccine in response to the sudden emergence of an avian-flu bug would require an extraordinary new effort, she said.

"We don't now have the capacity to do both," she said.