Threat of 'superflu' rampage as mutant viruses resist drugs
Pastor Dale Morgan
*Threat of 'superflu' rampage as mutant viruses resist drugs*
By Richard Gray, Science Correspondent
(Filed: 01/10/2006)
The drive to fight deadly flu pandemics with special antiviral drugs
risks creating an untreatable "superflu", the head of -Britain's public
health watchdog has warned.
Sir William Stewart, the chairman of the Health Protection Agency,
warned that the widespread use of antiviral drugs to treat illnesses,
including bird flu and seasonal influenza, is causing- viruses to mutate
into drug-resistant- forms.
He claimed that drug-resistant viruses now represented as big a threat
to public health as antibiotic-resistant superbug bacteria, such as
MRSA. His comments come as bird experts were once again placed on alert
for cases of avian flu returning to Britain with migrating birds.
The autumn migration of waterfowl triggered the spread of the deadly
H5N1 virus into western Europe and Britain for the first time last year,
as the disease spread rapidly in wild birds trying to escape the cold
weather. A dead swan discovered in Fife, Scotland, in April this year,
was the only bird flu case to be found in a wild bird in Britain.
Officials at the Department of Health confirmed that, last week, it
received the last of its stockpile of 14.6 million doses of the
antiviral drug Tamiflu, which will be used if bird flu mutates into a
human flu pandemic.
But Sir William, a former chief scientific adviser to the Government,
fears that the drug will be useless if the flu virus develops resistance
to it during the mass medication that would be necessary in a pandemic.
"With pandemic flu, once it develops antiviral resistance in one area,
it is likely to spread quickly," he told The Sunday Telegraph. "One of
our concerns is that we get Tamiflu-resistant strains emerging.
"Unfortunately, it is unknown if Tamiflu will be effective when pandemic
flu emerges and how long it will be effective for. Anti-viral resistance
is becoming as big a problem as antibiotic resistance." Sir William
stressed, however, that it was better to have stocks of antiviral drugs
that helped patients fight non-resistant flu strains than no drugs at
all to protect the population.
Meanwhile, last night, bird experts warned that the spectre of bird flu
infecting flocks in Britain would return this winter, as ducks and swans
migrated south over the coming months.
The H5N1 virus spread rapidly through bird flocks in 15 European
countries, including Turkey, France, Germany, Italy, Austria and
Denmark, after last year's winter migration. Cold weather from the east
forced the birds to move west as they sought food.
"The risk from bird flu is likely to be as great this year as it was, at
its height, last year," said Dr Bob McCracken, of the British Veterinary
Association. "We have to ensure that wild birds arriving in the UK are
being monitored."
The Department for Environment, Food and Rural Affairs has also launched
a revised strategy to screen migrating wild birds for bird flu,
including stepping up sampling for the disease in areas that have high
numbers of migrating waterfowl. It has also placed orders for 10 million
doses of avian influenza vaccine for poultry.
Health officials fear that if the H5N1 virus combines with human flu it
could create a new strain that would cause a pandemic. Government
predictions suggested that up to 700,000 people could die in such an
outbreak.
Concerns that a pandemic flu virus might develop resistance to Tamiflu
emerged last year, after reports from Vietnam that H5N1 virus was
showing signs of decreased sensitivity to the drug.
Figures from the World Health Organisation also show that approximately
0.4 per cent of adult seasonal flu cases and 5 per cent of child cases
treated with Tamiflu have already developed immunity to the drug.
Prof Jeremy Farrar, an expert on flu virus drug resistance at Oxford
University, said it was essential that more flu drugs were developed if
doctors were to fight a pandemic.
"We need more than one or two drugs available so we can combine them to
prevent resistance, or to have alternatives if resistance develops to
the first-line therapy," he said.
A spokesman for Roche, Tamiflu's maker said resistance to the drug was
"extremely rare".