Swine flu virus may be now resistant to key medicine Tamiflu, raising fears a new outbreak may be difficult to fight, Australian research has warned.
While just 2 per cent of swine flu (H1N1) strains around the world are resistant to Tamiflu, the Australian research found mutations in all strains of the swine flu that suggest they might be prone to develop resistance.
Researchers found that one in five cases of swine flu in one area of Australia in 2011 were resistant to the antiviral medicine.
Dr Aeron Hurt from the World Health Organisation collaborating centre for flu research in Melbourne, said the bug appears more prone than other types of flu to developing drug resistance, The Australian reported.
Tamiflu resistance develops when an individual under treatment receives the drug to control their symptoms. In most flu viruses, the changes that make the virus resistant to treatment also make it less likely to spread to others.
With swine flu, this has not happened and the virus remains fit enough to spread to others, Hurt said.
Research on patients in Newcastle, New South Wales in 2011 found just one person in the area had used Tamiflu but the resistant form of the virus spread to 20 per cent of all those who developed swine flu in that region, News Limited Network reported.
"Widespread transmission of a fit resistant strain is of significant public health concern," Hurt will tell a conference in Canberra tomorrow.
The only way to combat the growth of drug resistant strain of the virus is to save medicines for the most needy cases, he said.
Swine flu has not yet developed resistance to Relenza, an inhaled form of anti-viral treatment.
