Scientists in Desperate Race With Bird Flu
Will Killer Flu Bug Emerge Before We Are Ready?
Early Treatment May Help
Two flu drugs are active against bird flu: Tamiflu and Relenza. Tamiflu is taken orally, while Relenza must be inhaled. Because bird flu can infect organs other than the lungs, Tamiflu is considered the treatment of choice.
However, treatment must begin very soon after symptoms appear. Hayden and colleagues say that for severe cases of H5N1 bird flu, it's reasonable to use high doses of Tamiflu -- double the usually recommended dose.
A Bird Flu Pandemic
What experts worry about is that bird flu could learn to spread more easily among humans. This could happen in two ways. The bird virus could simply adapt to humans over time. Or a person could get infected with bird flu and human flu at the same time. Two viruses infecting the same person could swap gene segments. This "reassortant" virus might end up with the gene that lets it spread among humans.
It seems very easy for this to happen. Is it possible that for some reason bird flu just can't evolve into a human flu?
"I am not reassured that because it hasn't happened yet it will not occur," Hayden says. "I think we are watching an evolving event. There is real concern that either through transport of poultry or migratory birds, the virus will spread further. And that will increase the possibility it will reassort with a human virus or adapt to humans. Then one would be into a pandemic event."
Pandemic flu -- a flu bug that sweeps the globe -- happens every 10 to 40 years, says Stephen Morse, PhD, founding director of the Center for Public Health Preparedness at Columbia University's Mailman School of Public Health.
"All of us virologists and infectious disease epidemiologists who worry about flu for a living, we all feel a pandemic is virtually inevitable -- as inevitable as any unpredictable event can be," Morse tells WebMD. "We don't know if it will be a 1918-like epidemic, which is what we all fear -- the worst natural disaster we know of in history -- or whether it will be more of a standard pandemic like 1957 or 1968, where we have 4 million deaths rather than 100 million."
But if the next pandemic is bird flu, there really is no precedent. The terrible 1918 flu had a mortality [death] rate of only 2%, Morse says.
"The extra charge on that bomb is that H5N1 bird flu has a high mortality rate," he says. "That is one of the things that is very worrisome about this virus: A pandemic would mean a lot of people who are very sick. An H5 pandemic would be something very serious to contemplate."
Race Against Time
Nobody knows whether bird flu really will cause a pandemic. But researchers, governments, and drug companies are taking it very, very seriously.