is bird flu?
Like humans and other
species, birds are susceptible to flu. There are 15 types
of bird, or avian, flu. The most contagious strains, which
are usually fatal in birds, are H5 and H7. There are nine
different types of H5. The nine all take different forms -
some are highly pathogenic, while some are pretty
harmless. The type currently causing concern is the deadly
strain H5N1, which can prove fatal to humans. Migratory
wildfowl, notably wild ducks, are natural carriers of the
viruses, but are unlikely to actually develop an
infection. The risk is that they pass it on to domestic
birds, who are much more susceptible to the virus.
do humans catch bird flu?
Bird flu was thought only to
infect birds until the first human cases were seen in Hong
Kong in 1997. Humans catch the disease through close
contact with live infected birds. Birds excrete the virus
in their faeces, which dry and become pulverised, and are
then inhaled. Symptoms are similar to other types of flu -
fever, malaise, sore throats and coughs. People can also
develop conjunctivitis. Researchers are now concerned
because scientists studying a case in Vietnam found the
virus can affect all parts of the body, not just the
lungs. This could mean that many illnesses, and even
deaths, thought to have been caused by something else, may
have been due to the bird flu virus.
it possible to stop bird flu coming into a country?
Because it is carried by
birds, there is no way of preventing its spread. But that
does not mean it will be passed to domestic flocks.
Experts say proper poultry controls - such as preventing
wild birds getting in to poultry houses - which are
present in the UK, should prevent that happening. In
addition, they say monitoring of the migratory patterns of
wild birds should provide early alerts of the arrival of
infected flocks - meaning they could be targeted on
many people have been affected?
As of 27 April 2006, the
World Health Organization (WHO) had confirmed 204 cases of
H5N1 in humans in Azerbaijan, Cambodia, China, Egypt,
Indonesia, Iraq, Thailand, Turkey and Vietnam, leading to
113 deaths. For the latest WHO information on the numbers
of humans infected and killed by avian flu, see related
internet links section on right of page.
quickly is the disease spreading?
After bird flu claimed its
first human victim - a three-year-old boy in Hong Kong in
May 1997 - the disease was not detected again until
February 2003, when a father and son were diagnosed with
H5N1, again in Hong Kong. Since then it has spread
westwards through Asia, the Middle East, Europe and
Africa. Despite mass culls, exclusion zones and other
measures put in place to prevent its spread, the H5N1
virus has continued to travel. In one week in February
2006, Italy, Greece, Bulgaria, Germany, Austria, France,
Slovenia, India, Iran and Egypt confirmed their first
cases of H5N1 in wild birds. In April 2005, a dead swan in
Scotland was found to have the strain.
it can't yet be passed from person to person?
For the most part, humans
have contracted the virus following very close contact
with sick birds. There may have been examples of
human-to-human transmission, but so far not in the form
which could fuel a pandemic. A case in Thailand indicated
the probable transmission of the virus from a girl who had
the disease to her mother, who also died. The girl's aunt,
who was also infected, survived the virus. UK virology
expert Professor John Oxford said these cases indicated
the basic virus could be passed between humans, and
predicted similar small clusters of cases would be seen
again. It is not the only instance where it has been
thought bird flu has been passed between humans. In 2004,
two sisters died in Vietnam after possibly contracting
bird flu from their brother who had died from an
unidentified respiratory illness. In a similar case in
Hong Kong in 1997, a doctor possibly caught the disease
from a patient with the H5N1 virus - but it was never
would the consequences of a mass outbreak be?
Once the virus gained the
ability to pass easily between humans the results could be
catastrophic. Worldwide, experts predict anything between
two million and 50 million deaths. However the mortality
rate - which presently stands at around 50% of confirmed
cases - could decline as it mutates, they say.
there a vaccine?
There is not yet a definitive
vaccine, but prototypes which offer protection against the
H5N1 strain are being produced. But antiviral drugs, such
as Tamiflu which are already available and being
stockpiled by countries such as the UK, may help limit
symptoms and reduce the chances the disease will spread.
Concerns have been prompted by news that patients in
Vietnam have become partially resistant to the Tamiflu,
the drug that doctors plan to use to tackle a human bird
flu outbreak. Scientists say it may be helpful to have
stocks of other drugs from the same family such as Relenza
I continue to eat chicken?
Yes. Experts say avian flu is
not a food-borne virus, so eating chicken is safe. The
only people thought to be at risk are those involved in
the slaughter and preparation of meat that may be
infected. However, the Who recommends, to be absolutely
safe all meat should be cooked to a temperature of at
least 70C. Eggs should also be thoroughly cooked.
Professor Hugh Pennington of Aberdeen University
underlined the negligible risk to consumers: "The virus is
carried in the chicken's gut. "A person would have to dry
out the chicken meat and would have to sniff the carcass
to be at any risk. But even then, it would be very hard to
is being done to contain the virus in the countries
Steps have been taken to try
to stop the disease spreading among birds. Millions of
farmyard birds have been culled, while millions more have
been vaccinated and confined indoors. Areas where the
disease has been found have been isolated and some
countries have banned imports of live birds and poultry
products. In January 2006 international donors pledged
$1.9bn (£1.1bn) in the fight against bird flu, while the
World Health Organization has devised a rapid-response
plan to detect and contain a global flu pandemic. There
are also measures recommended when a wild infected bird is
found, including protection and surveillance zones.
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