Some facts on the outbreak of bird flu in Southeast Asia
Some facts on the outbreak of bird flu in Southeast Asia
An eight-year-old girl has been confirmed as the fifth person to
die in Vietnam from an outbreak of bird flu, the World Health
Organisation said.
The outbreak in Vietnam, as well as outbreaks in South Korea,
Japan and Taiwan, have shaken Asia's poultry industry. Thailand,
which produces about one billion chickens a year and exports
mainly to Japan and Europe, said it was free of bird flu but was
battling an outbreak of poultry cholera.
Here are the main facts about the disease.
What is bird flu?
The outbreaks in South Korea, Japan and Vietnam have been caused
by the H5N1 strain of avian influenza viruses. Avian influenza
can range from a mild disease that has only minor effects to a
highly infectious fatal version. It spreads in the air and in
manure.
It can also be transmitted by contaminated feed, water,
equipment and clothing. Clinically normal waterfowl and sea birds
may introduce the virus into flocks. Broken contaminated eggs may
infect chicks in incubators.
Is bird flur harmful to humans?
Human fatalities from avian influenza are very rare and were
unknown before 1997, when six people in Hong Kong died after
being infected with the H5N1 strain.
Early last year, a 33-year-old Hong Kong man contracted the
H5N1 virus and died of pneumonia.
In April 2003, a veterinarian who had been working on a Dutch
farm infected with bird flu became ill with an H7 strain of the
disease and died of pneumonia. The vet did not take medication
against avian and human flu. Rules have been tightened to ensure
anyone who comes in contact with infected farms does so.
Could bird flu become a human epidemic?
Although avian flu is very infectious in birds, it does not
spread easily among humans.
There is a danger, however, that an avian virus mixes with a
human influenza and forms a new disease. The new virus could
share genetic material from both viruses, being highly infectious
like human flu and dangerously fatal like the avian variety.
Humans would have no natural defence against it.
New influenza strains have caused pandemics, most recently in
1956-1957 and 1967-1968, killing a combined 4.5 million people.
Clinical diagnosis
The World Organization for Animal Health says the incubation
period for the disease in poultry is 3-5 days. It has various
affects on birds, ranging from drastic declines in egg production
to sudden deaths. There is no treatment.