Swine flu update: bringing home the bacon.

In 6 weeks, swine influenza A(H1N1) virus has spread from 10 to 74 countries. Australia has the fifth highest number of cases and the third highest rate of infection among the top five affected nations. People who are hospitalised with or die from this novel virus are more likely to have predisposing risk factors. There is a predilection for younger age groups and sparing of older age groups. This may be a property of influenza A viruses in general rather than being specific to swine influenza A. If unchecked, the sheer number of cases may lead to much higher numbers of deaths and hospitalised patients than would normally be attributed to a standard influenza season. Paradoxically, the low case-fatality rate of the virus raises the question of how best to approach management of this outbreak. It is uncertain how an expected vaccine against the novel virus will be used.