# 822
Despite the soothing words from the various agencies in the UK over the past couple of days; that the outbreak of H7N2 is `mild' and poses `little danger to public health', there are some scientists who aren't quite as confident.
While H7N2 has, to date, produced only mild symptoms; it too mutates, just like all influenza viruses. The mild virus of today could become more troublesome days, weeks or months from now.
As I pointed out in April, It Isn't Just Bird Flu we need to worry about. There are a host of pathogens, including numerous influenza viruses, that have pandemic, or epidemic potential.
This from the International Herald Tribune.
Mild bird flu in Britain has pandemic potential, experts say
The Associated Press
Published: May 29, 2007
LONDON: The four presumed human H7N2 bird flu cases identified in Britain last week are a reminder that the next flu pandemic could be sparked by a virus other than the feared H5N1 strain, experts say.
While the global health community's attention in recent years has targeted the H5N1 virus, which has killed at least 186 people worldwide since 2003, some experts worry that attention is being diverted from seemingly less dangerous bird flu subtypes like H7.
"There may be a bit of complacency when it comes to recognizing the pandemic potential of H7 viruses," World Health Organization bird flu expert Dr. Michael Perdue said Monday.
Last week, British authorities confirmed that four people apparently tested positive for H7N2, a mild strain of bird flu, after 15 chickens at a small farm in Wales died. Health officials are currently investigating 36 people who may also be infected, of whom 11 have symptoms of flu or conjunctivitis.
Having so many human cases at once is a potential concern. In Asia, where H5N1 has circulated most widely, millions of people have been exposed to millions of infected birds, resulting in about one new infection per week.
"Here, we're talking about a small number of birds and yet we still have four cases," Perdue said. "Unless there's something unusual about the contact with birds, that suggests the virus is finding new ways of getting into humans."
The H7 subtype has previously sparked human outbreaks. In a large outbreak in the Netherlands in 2003, 89 human cases were reported, mostly of conjunctivitis, as well as one death. There were also at least three likely instances of human-to-human transmission involving family members of poultry workers. In the case of the single fatality, officials noticed that particular virus had about 10 mutations.
British officials have been quick to reassure the public that the "low pathogenic" H7N2 virus — in comparison to the "highly pathogenic" H5N1 virus — poses little risk to the population. Indeed, H7N2 appears to cause only mild symptoms such as eye infections.
But low pathogenic viruses can quickly morph into highly pathogenic ones, sometimes within weeks. Too little is known about flu viruses to predict with any certainty which ones are most lethal for humans.
"The pandemic risk from low pathogenic avian viruses is almost as bad as that from highly pathogenic avian viruses," said Dr. Angus Nicoll, an influenza expert at the European Centre of Disease Prevention and Control.
I still consider H5N1 to be our biggest worry today, but I'm not turning my back on the rest of the field.
You never know when a dark horse candidate will make a run.
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