- WASHINGTON (AP) -- 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.
- 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.
- There had been small appearances of the H1-type of avian
viruses in other years, but nothing like the H5 now rampaging through the
birds of Asia.
- "We are seeing a highly pathogenic strain of influenza
virus emerge to an extraordinary proportion across the entire western component
of Asia," she said. "The reason this is so ominous is because
of the evolution of flu. ... You may see the emergence of a new strain
to which the human population has no immunity."
- Study already has shown that the virus can infect cats
who can then infect other cats, which Gerberding said was "another
harbinger" of the possibility of a human pandemic.
- "The science here is all alerting us that we have
a great deal to be concerned about," she said.
- 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
- 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 full-blown epidemic of an H1-type of flu in this
- CDC is also plugged into an international communication
and monitoring system that, it is hoped, will give an early warning of
the emergence of a deadly new flu.