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Dead swan is Britain's first case of H5N1 flu
By Sarah Lyall The New York Times FRIDAY, APRIL
7, 2006
LONDON - A swan found dead in eastern Scotland
has tested positive for the deadly strain of bird
flu, government officials said Thursday, making
it the first recorded case of the disease in a
wild bird in Britain.
The bird, believed to be a native mute swan,
was discovered eight days ago in the harbor at
Cellardyke, a small coastal town in Fife, northeast
of Edinburgh. Officials have established a 3 kilometer,
or 1.8-mile, protection zone around the spot where
it was found to prevent the poultry moving in
and out of the area.
Officials emphasized that while the swan was
suffering from the H5N1 strain of flu, there was
no immediate danger to humans and no danger yet
to the poultry supply. Although more than 100
people have died in other countries from bird
flu, which is deadly when passed on to humans,
the victims had worked in close contact with or
handled birds that died of bird flu.
Bird flu has been gradually making its way across
Europe, striking countries like Germany, France,
Denmark, Italy, Poland, Switzerland and Greece.
But Britain has been bracing itself. Cobra, the
government's emergency planning group, named for
Cabinet Office Briefing Rooms, where it usually
convenes, met Thursday morning in London with
officials from the environment and health departments,
the Scottish Executive and the prime minister's
office to map out contingency plans.
In a statement, the National Farmers' Union said
that the news was "an unwelcome and important
development from the point of view of poultry
health," but that its members were well prepared
to deal with it.
With tests now being conducted on an additional
two swans found dead in Glasgow, "further
cases of avian influenza in wild swans in Scotland
cannot be ruled out," the union said. The
biggest fear now is that the disease will move
from the wild bird population to domestic fowl,
affecting the poultry market and setting off a
panic among consumers.
The chief veterinary officer of Scotland, Charles
Milne, said the government had set up a 2,500-
square-kilometer, or 965-square-mile, surveillance
zone to monitor bird movements. The zone contains
175 registered poultry farms, with a total of
3.1 birds. Forty-eight of those are free-range
operations, with some 260,000 birds. Milne said
farmers were being ordered to separate their domestic
fowl from wild birds, and to move their birds
indoors if possible.
Scientists point finger at pets
Five leading European scientists criticized officials
involved in human and animal health in an article
Thursday, saying the officials are not doing enough
to monitor cats, dogs and other carnivores for
their possible role in transmitting avian influenza,
Lawrence K. Altman of The New York Times reported
from New York.
Writing in the journal Nature, the scientists
also urge people living in areas where the H5N1
virus has infected poultry and other birds to
keep their cats indoors.
The scientists are from the Erasmus Medical Center
in Rotterdam and the Food and Agricultural Organization
of the United Nations. They directed much of their
criticism at the World Health Organization and
the World Organization for Animal Health for emphasizing
the lack of evidence that domestic cats play a
role in transmitting the virus.
Cats, tigers and leopards are known to have been
infected with the virus in Asia and Europe. An
author of the article, Albert Osterhaus, a virologist
and veterinarian at Erasmus Medical Center, has
performed experiments showing that cats can give
the virus to other cats. But whether they do so
in real life, and if so how often, is unknown.
Dick Thompson, spokesman for the World Health
Organization, said Wednesday that it agreed that
more work was needed to determine the role of
cats and other carnivores in the epidemiology
of avian influenza. Epidemiologists have found
no change in the way the virus is spreading or
causing illness, Thompson said. But he added,
"Obviously, there still are major gaps in
our knowledge and risk assessment."
He cited a resolution to be put before representatives
of the organization's member states at a meeting
in May saying that "given the close association
between domestic cats and people, vigilance for
signs that cats are becoming more widely infected
is essential."
Osterhaus said that his team was issuing a precaution
and not trying to sound too loud an alarm. The
team has found that cats can be infected through
the respiratory tract. Cats can also be infected
when they ingest the virus, which is a novel route
for influenza transmission in mammals. But cats
excrete only one- thousandth the amount of virus
that chickens do, or less, he said.
The concern is that if large numbers of carnivores
become infected the virus might mutate in a series
of events that could lead to an epidemic among
humans. But among the many unknowns is how long
cats can excrete the virus, the minimal amount
of virus it takes to cause infection and whether
cats can excrete the virus without developing
signs of illness.
Dogs, foxes, seals and other carnivores may be
vulnerable to the H5N1 virus, Osterhaus said.
Tests in Thailand have shown the virus has infected
dogs without causing apparent symptoms.
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