Otherwise healthy people who contract the H1N1 “swine flu” virus do not need to be treated with antivirals if their symptoms are uncomplicated, the World Health Organisation has said.

The WHO published new guidelines on Friday following a review by an international panel of experts of all available studies on the safety and effectiveness of drugs used to treat the H1N1 virus – particularly oseltamivir and zanamivir.

The panel found that when properly prescribed, oseltamivir could significantly reduce the risk of pneumonia and the need for hospitalisation. It recommended it should be given as soon as possible to patients presenting with severe illness or whose condition starts to deteriorate.

At risk groups, including those with underlying medical conditions and pregnant women should be treated with antivirals as soon as possible after symptom onset, the panel said. For other patients, carers and medical professionals should be alert to any of the following danger signs which indicate the disease is becoming more severe:

  • Shortness of breath, either during physical activity or while resting
  • Difficulty in breathing
  • Turning blue
  • Bloody or coloured sputum
  • Chest pain
  • Altered mental state
  • High fever lasting longer than three days
  • Low blood pressure
  • (In children) lethargy and little or no desire to play