24 février, 2005 09:25
Bird flu pandemic is possible, CDC warns
Mutated virus a very high threat in coming weeks, official says
The Associated Press
Updated: 7:19 a.m. ET Feb. 22, 2005
WASHINGTON - A bird flu virus may mutate to a human form that becomes as deadly as the ones that killed millions during three influenza pandemics of the 20th century.
Dr. Julie L. Gerberding, head of the Centers for Disease Control and Prevention, said Monday that scientists believe it is highly likely that the virus that has swept through bird populations in Asia will evolve into a pathogen deadly for humans.
"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 in remarks at the national meeting of the American Association for the Advancement of Science.
Although cases of human-to-human transmission have been rare, "our assessment is that this is a very high threat" based on the known history of the flu virus, she said.
72 percent mortality rate
In Asia, there have already 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, said Gerberding. 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.
The avian flu now spreading in Asia is part of what is called the H1 family of flu viruses. It is a pathogen that is notorious in human history.
"Each time we see a new H1 antigen emerge, we experience a pandemic of influenza," said Gerberding. In 1918, H1 appeared and millions died worldwide. In 1957, the Asian flu was an H2, and the Hong Kong flu in 1968 was a H3.
