Expert warns of A(H1N1)-bird flu mix scenario
MEXICO CITY: Bird flu kills more than 60 per cent of its human victims, but doesn’t easily pass from person to person. Swine flu — now called Influenza A(H1N1) — can be spread with a sneeze or handshake, but kills only a small fraction of the people it infects.
So what happens if they mix?
This is the scenario that has some scientists worried: The two viruses meet — possibly in Asia, where bird flu is endemic — and combine into a new bug that is both highly contagious and lethal and can spread around the world.
Scientists are unsure how likely this possibility is, but note that the new A(H1N1) strain — a never-before-seen mixture of pig, human and bird viruses — has shown itself to be especially adept at snatching evolutionarily advantageous genetic material from other flu viruses.
“This particular virus seems to have this unique ability to pick up other genes,” said leading virologist Robert Webster, whose team discovered an ancestor of the current flu virus at a North Carolina pig farm in 1998.
The A(H1N1) has sickened more than 2,300 people in 24 countries. While people can catch bird flu from birds, the bird flu virus — H5N1 — does not easily jump from person to person. It has killed at least 258 people worldwide since it began to ravage poultry stocks in Asia in late 2003. Two cases
The World Health Organization reported two human cases of bird flu on Wednesday. One patient is recovering in Egypt, while another died in Vietnam — a reminder that the H5N1 virus is far from gone. “Do not drop the ball in monitoring H5N1,” WHO Director-General Margaret Chan told health officials in Bangkok on Friday by video link. “We have no idea how H5N1 will behave under the pressure of a pandemic.”
Experts have long feared that bird flu could mutate into a form that spreads easily among people. The past three flu pandemics — the 1918 Spanish flu, the 1957-58 Asian flu and the Hong Kong flu of 1968-69 — were all linked to birds, though some scientists believe pigs also played a role in 1918.
Dr. Webster said bird flu should be a worry now. Bird flu is endemic in parts of Asia and Africa, and cases of A(H1N1) have already been confirmed in South Korea and Hong Kong.
Malik Peiris, a flu expert at Hong Kong University, said the more immediate worry is that swine flu will mix with regular flu viruses, as flu season begins in the Southern Hemisphere. — AP
So what happens if they mix?
This is the scenario that has some scientists worried: The two viruses meet — possibly in Asia, where bird flu is endemic — and combine into a new bug that is both highly contagious and lethal and can spread around the world.
Scientists are unsure how likely this possibility is, but note that the new A(H1N1) strain — a never-before-seen mixture of pig, human and bird viruses — has shown itself to be especially adept at snatching evolutionarily advantageous genetic material from other flu viruses.
“This particular virus seems to have this unique ability to pick up other genes,” said leading virologist Robert Webster, whose team discovered an ancestor of the current flu virus at a North Carolina pig farm in 1998.
The A(H1N1) has sickened more than 2,300 people in 24 countries. While people can catch bird flu from birds, the bird flu virus — H5N1 — does not easily jump from person to person. It has killed at least 258 people worldwide since it began to ravage poultry stocks in Asia in late 2003. Two cases
The World Health Organization reported two human cases of bird flu on Wednesday. One patient is recovering in Egypt, while another died in Vietnam — a reminder that the H5N1 virus is far from gone. “Do not drop the ball in monitoring H5N1,” WHO Director-General Margaret Chan told health officials in Bangkok on Friday by video link. “We have no idea how H5N1 will behave under the pressure of a pandemic.”
Experts have long feared that bird flu could mutate into a form that spreads easily among people. The past three flu pandemics — the 1918 Spanish flu, the 1957-58 Asian flu and the Hong Kong flu of 1968-69 — were all linked to birds, though some scientists believe pigs also played a role in 1918.
Dr. Webster said bird flu should be a worry now. Bird flu is endemic in parts of Asia and Africa, and cases of A(H1N1) have already been confirmed in South Korea and Hong Kong.
Malik Peiris, a flu expert at Hong Kong University, said the more immediate worry is that swine flu will mix with regular flu viruses, as flu season begins in the Southern Hemisphere. — AP
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