Poultry slaughtered as Strain of Human Bird Flu hits Britain
Pastor Dale Morgan
Poultry slaughtered as Strain of Human Bird Flu hits Britain*
By JENNIFER QUINN
The Associated Press
Friday, May 25, 2007; 9:24 PM
LONDON -- Four people have tested positive for a mild strain of bird
flu, British authorities said Friday. The cases _ which are not the
feared H5N1 strain, but the less dangerous H7N2 subtype _ were reported
after poultry died at a small farm in north Wales.
Tests were performed on nine people associated with the farm, and the
Health Protection Agency said in a news release that four people had
tested positive for the H7N2 strain of the virus.
Three of the nine were hospitalized, but have since been discharged, the
agency said.
The Welsh health authorities said that in all but one of the four human
cases the virus had spread from poultry. The other case may have been
transmitted from person to person.
"Although the number of people involved is very small, we could be
dealing with some spread of the H7 flu virus within the household
setting," said Dr. Marion Lyons, a communicable disease specialist with
the Welsh health service. "We are treating this possibility very seriously."
Officials are now following up all close contacts of the people who were
ill as a precaution.
The H7 subtype of bird flu is believed to be less virulent than H5, but
it has in the past caused human cases, and was responsible for a large
outbreak in the Netherlands. In that outbreak in 2003, there were 89
mild cases of H7N7, and one person died.
Most of the cases in the Netherlands were conjunctivitis, a mild eye
infection.
"The mortality rate of H7 viruses is not on the order of H5N1," said Dr.
Michael Perdue, a World Health Organization bird flu expert. Experts
estimate that nearly half or more of all people who contract H5N1 die.
While H7 viruses tend to cause milder illnesses in humans, they still
have the potential to ignite a global flu outbreak and should be watched.
"A low pathogenic H7 virus might not be picked up as easily as a highly
pathogenic virus," said Perdue, explaining that the mild symptoms of H7
infection might be mistaken for ordinary flu, causing experts to lose
valuable time tracking an emerging pandemic.
Like all flu viruses, H7 evolves constantly. Other bird flu subtypes
have also caused illnesses in humans. Surveillance in Europe for all
bird flu viruses has greatly increased in recent years.
While global health experts have been focused on H5N1 as the strain most
likely to cause the next flu pandemic, it is also possible that another
subtype, such as H7, could ultimately be responsible. "I'd hate to
predict anything with bird flu," said Perdue.
The farm came to the attention of British authorities after a number of
chickens died.
Dr. Christianne Glossop, the chief veterinary officer for Wales, said in
a statement that the chickens had tested positive for H7N2.
A 1.6-mile exclusion zone was put in place around the farm, and the
remaining chickens have been slaughtered.