Fears of Global Bird Flu Outbreak Increase
Human Pandemic Would Kill Many Millions, But Crucial Facts Still Missing
Public Health Response Slow
The WHO last month convened an informal meeting of all 11 companies that make flu vaccines, regulatory authorities, and the health ministers of several nations. The bottom line: If and when bird flu breaks out in humans, there won't be a vaccine for at least several months.
"The most basic thing we are recommending is increased surveillance. It is important we have a global surveillance system in place," the WHO's Cheng says. "We are working with national authorities to accelerate the process of making a vaccine."
Surveillance means identifying human-to-human bird flu transmission in its earliest stages. That's not an easy task, given that bird flu is spreading in some of the most remote and rural areas of Asia. And people whose livelihood depends on small flocks of chickens are loath to report bird deaths when it means that public health officials will exterminate their only source of income.
Fortunately, there's hope that a worldwide pandemic could be contained. Ira Longini, PhD, professor of biostatistics at Rollins School of Public Health at Emory University in Atlanta, is part of an international team that's developing mathematical models of flu outbreaks. The models, nearing completion, predict exactly how far a flu outbreak will spread under different circumstances.
The models are sobering. For example, Longini's earlier work shows that if a flu outbreak were like the relatively mild 1957 Asian flu virus, it would infect 93 million Americans and cause 164,000 U.S. deaths.
Would a bird flu outbreak be worse? Probably. But Longini says it's highly unlikely that a bird flu would be as deadly as some people fear.
"Based on past experience, we don't have to panic," Longini tells WebMD. "It's clear that pandemic flu is inevitable. It is going to happen, and it could be a fairly pathogenic strain and could be a real problem. Right now, H5N1 bird influenza looks like it is fatal in 70% of cases. But this 70% figure is totally absurd. It has never been true of any human flu strain. I have never seen any evidence that human influenza is anywhere near that virulent. Case fatality of even highly virulent strains are a couple of deaths per 10,000 people infected."