Swine flu's viral vigour

Swine flu attacks the airways in a more sustained way than the standard virus, the first full study of the virus shows.

The University of Wisconsin study, which appears in the journal Nature, said tests showed swine flu multiplies in greater numbers across the respiratory system, and causes more damage.

The study on animals also showed that the strain penetrates deeper into the respiratory tissues - making it more likely to cause pneumonia.

The team stressed that the vast majority of swine flu cases were mild and reacted to anti-viral drugs.

- AGENCIES