http://www.bloomberg.com/apps/news?pid=20601124&sid=a6hwRhROldwI
Swine Flu Supplanting Seasonal Strains in Australia?s Victoria
By Jason Gale
June 26 (Bloomberg) -- Swine flu is supplanting seasonal strains in Australia?s Victoria state, suggesting the pandemic virus will be the major cause of influenza this winter.
Tests on 138 type-A flu samples collected by a network of doctors confirmed 60 cases of the new A/H1N1 variant and only five of seasonal influenza in the eight weeks ended June 21, according to a report today by the Victorian Infectious Diseases Reference Laboratory in Melbourne.
A typical feature of previous pandemics is for a novel virus to crowd out the most common flu strains during winter, Margaret Chan, director-general of the World Health Organization, said this month. It?s also a factor the agency will consider in determining when vaccine makers should switch to producing only shots against the pandemic virus, which is spurring an increase in flu cases in Australia including New South Wales state.
?We are seeing a big increase compared to the same stage of the flu season last year, and the increase is predominantly in 5- to 16-year-olds,? Kerry Chant, chief health officer for New South Wales, said in a statement today. Two children are in intensive care and two other people hospitalized, she said.
The eastern state, Australia?s most populous, has 653 confirmed cases of swine flu, the second highest number in the nation after neighboring Victoria state.
Health officials in Victoria have recorded 1,509 cases from laboratory tests and stopped analyzing specimens from patients with mild disease earlier this month as part of the state?s response to the virus.
?Many? Cases
A third person in Victoria died after being diagnosed with the new H1N1 virus, Rosemary Lester, the state?s acting chief health officer, said in a statement today. ?Many milder cases? haven?t been tested, she said.
Victoria?s influenza sentinel surveillance network diagnosed flu-like illness in 21.9 of every 1,000 patients seen in the week ended June 21, the report showed. That?s up from 17 per 1,000 a week earlier.
The network comprises 87 general practitioners across the state who test a portion of their patients for flu to give authorities an indication of flu activity in the community.
Unlike seasonal flu, from which the elderly suffer the most death and disease, the new bug is targeting the young and causing potentially fatal complications in otherwise healthy people aged 30 to 50, pregnant women and those with asthma, diabetes and obesity, according to the WHO.
Disease trackers are watching how swine flu behaves during the Southern Hemisphere winter to gauge flu activity when the weather turns colder in Europe and North America later this year.
Influenza is more common in winter because virus particles persist longer in the air during colder, drier weather. The bug is also transmitted more easily in winter because people tend to stay close together indoors.
Still, flu is being diagnosed at an increasing rate during summer in some Northern Hemisphere countries, including England and Wales, because of the spread of swine flu, a bug to which most people have no immunity.
To contact the reporter on this story: Jason Gale in Singapore at j.gale@bloomberg.net
Last Updated: June 26, 2009 05:42 EDT
Swine Flu Supplanting Seasonal Strains in Australia?s Victoria
By Jason Gale
June 26 (Bloomberg) -- Swine flu is supplanting seasonal strains in Australia?s Victoria state, suggesting the pandemic virus will be the major cause of influenza this winter.
Tests on 138 type-A flu samples collected by a network of doctors confirmed 60 cases of the new A/H1N1 variant and only five of seasonal influenza in the eight weeks ended June 21, according to a report today by the Victorian Infectious Diseases Reference Laboratory in Melbourne.
A typical feature of previous pandemics is for a novel virus to crowd out the most common flu strains during winter, Margaret Chan, director-general of the World Health Organization, said this month. It?s also a factor the agency will consider in determining when vaccine makers should switch to producing only shots against the pandemic virus, which is spurring an increase in flu cases in Australia including New South Wales state.
?We are seeing a big increase compared to the same stage of the flu season last year, and the increase is predominantly in 5- to 16-year-olds,? Kerry Chant, chief health officer for New South Wales, said in a statement today. Two children are in intensive care and two other people hospitalized, she said.
The eastern state, Australia?s most populous, has 653 confirmed cases of swine flu, the second highest number in the nation after neighboring Victoria state.
Health officials in Victoria have recorded 1,509 cases from laboratory tests and stopped analyzing specimens from patients with mild disease earlier this month as part of the state?s response to the virus.
?Many? Cases
A third person in Victoria died after being diagnosed with the new H1N1 virus, Rosemary Lester, the state?s acting chief health officer, said in a statement today. ?Many milder cases? haven?t been tested, she said.
Victoria?s influenza sentinel surveillance network diagnosed flu-like illness in 21.9 of every 1,000 patients seen in the week ended June 21, the report showed. That?s up from 17 per 1,000 a week earlier.
The network comprises 87 general practitioners across the state who test a portion of their patients for flu to give authorities an indication of flu activity in the community.
Unlike seasonal flu, from which the elderly suffer the most death and disease, the new bug is targeting the young and causing potentially fatal complications in otherwise healthy people aged 30 to 50, pregnant women and those with asthma, diabetes and obesity, according to the WHO.
Disease trackers are watching how swine flu behaves during the Southern Hemisphere winter to gauge flu activity when the weather turns colder in Europe and North America later this year.
Influenza is more common in winter because virus particles persist longer in the air during colder, drier weather. The bug is also transmitted more easily in winter because people tend to stay close together indoors.
Still, flu is being diagnosed at an increasing rate during summer in some Northern Hemisphere countries, including England and Wales, because of the spread of swine flu, a bug to which most people have no immunity.
To contact the reporter on this story: Jason Gale in Singapore at j.gale@bloomberg.net
Last Updated: June 26, 2009 05:42 EDT
