Bird Flu Spread Among Humans Would Be Deadly
Human Cases Mount, but Still No Giant Leap to Mankind
Feb. 22, 2004 -- This year's flu season was scary. But it was only a tiny taste of what would happen if bird flu spread among humans -- something that fortunately has not happened.
This year's Fujian flu was just a slightly different kind of flu. But totally new flu bugs -- such as the 1918-1920 Spanish flu, the 1957-1958 Asian flu, and the 1967-1968 Hong Kong flu -- are major killers. The 1918 flu killed 500,000 Americans; the Asian flu, 70,000; the Hong Kong flu, a relatively meager 40,000. Experts think all of these flu bugs jumped to humans from birds.
Now there's a new flu bug wreaking havoc on poultry -- and people who come into contact with them -- in East Asia. It's officially known as H5N1 avian influenza. So far, the only humans to get it have caught it from infected chickens or ducks. And among the patients that doctors have seen, nearly 70% percent of them have died. To date, there have been 32 lab-confirmed cases and 22 deaths.
However, Tran Tinh Hien, MD, tells WebMD he's sure that some people have mild or no symptoms and thus are not seen by a doctor. Perhaps there is only a small number of people with severe symptoms from bird flu, he says. Hien is lead researcher of a bird flu study released early today that is scheduled to appear in the March 18 issue of The New England Journal of Medicine.
During the 1990s, 36,000 Americans (90% of them elderly) died in a typical flu season. The CDC estimates that if a new flu were as lethal as the 1957-1958 flu bug, it would kill between 89,000 and 207,000 Americans. It would sicken 20 million to 47 million people and lead to some 730,000 hospitalizations. But there's strong evidence that the bird flu now spreading through East Asia would be worse. Much worse.
Hien's report contains grim findings from a study of 10 people who caught bird flu directly from infected poultry. Eight of them died, note Hien and Jeremy Farrar, MD, PhD, of the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam, and colleagues.
"This particular infection is clearly difficult to catch and seems to come about following very close contact with poultry. There is no evidence of human-to-human transmission among our cases," Farrar tells WebMD.
But there is some hopeful news. "In my hospital no more confirmed cases have been admitted to the hospital for two weeks," Hien says.
People get bird flu via close contact with infected birds or their feces. There is no evidence that people get the infection from eating fully cooked chicken or eggs. However, tigers in a zoo near Bangkok appear to have been infected with bird flu by eating raw chickens. CDC officials recommend fully cooking chicken and eggs for Americans living or traveling in areas where there's bird flu.