Steve Connor: Australia holds key to flu warning

Australia has one of the fastest-growing outbreaks of swine flu in the world, which is especially dangerous for a southern hemisphere country entering its winter flu season.

With the number of confirmed cases yesterday reaching 1,260, Australia has experienced a four-fold increase in infections in a single week. The state of Victoria and particularly its capital, Melbourne, are the worst hit, with more than 1,000 confirmed cases of the H1N1 virus.

Australian authorities said that many of the confirmed cases could not be traced back to travellers or to common infection sites such as schools, indicating that the virus was spreading freely within local communities as it has in Mexico, the US and Canada.

If confirmed, this free spread within entire communities will be a critical fact that could tip the World Health Organisation into declaring a full-scale global pandemic. If the virus is spreading freely within communities within at least two WHO regions, then the organisation is obliged to declare a pandemic, with all that this entails for the pandemic flu plans of its member countries.

Yesterday the WHO's director general, Margaret Chan, held telephone discussions with the health ministries of "seven or eight" countries – thought to include Australia and Chile – where the swine-flu virus is spreading rapidly. She has vowed that once she gets "indisputable evidence" of community-wide spread in two regions she will make an announcement on declaring a pandemic.

Most of those affected in Australia are suffering only mild symptoms, but the Queensland health minister, Paul Lucas, has warned that the infectious respiratory condition would inevitably claim some lives.

Authorities in New South Wales and South Australia, as well as the national capital, Canberra, have told children who have recently travelled to Melbourne to stay away from school for a week on their return home. The entire squad and staff of the Brisbane Broncos rugby league club have been put into quarantine as tests are carried out on a player suspected of contracting the virus.

Australia's National Pandemic Emergency Committee is to decide whether to upgrade the national pandemic alert status from "contain" to "sustain", after the Australian Health Protection Committee reviewed the virus's spread from one state to another.

The other country of concern to the WHO is Chile, which has reported nearly 1,700 confirmed cases of swine flu and which, like Australia, is entering its mid-winter flu season. Scientists are concerned that the pandemic strain of swine flu may spread rapidly in densely populated regions of South America.