London - The virus responsible for the swine flu pandemic of 2009 is becoming increasingly resistant to the main drug used to treat it, research has shown.
An increasing number of cases of the virus, H1N1, are being found with developing resistance to Tamiflu which was stockpiled in large amounts by governments- including in Britain - when it was feared the new swine flu mutation would irresistibly sweep the world.
First detected in Mexico, the 2009 virus was a new strain of H1N1 which combined with a Eurasian pig flu virus to become newly potent. The resultant pandemic struck over 74 countries, and although deaths were initially assessed by the World Health Organisation at 18 500, it later admitted this was probably a gross underestimate.
Tamiflu was the main drug against the outbreak - but now Australian scientists say it is encountering increased resistance.
Dr Aeron Hurt, of the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne, analysed circulating H1N1 strains, and found that although the overall frequency of Tamiflu resistance was relatively low, an increasing proportion of these viruses are being detected in patients not being treated with Tamiflu.
This suggests a resistant strain could be emerging since it must be being transmitted to patients never treated with that drug.
A widespread cluster of cases of Tamiflu-resistant influenza in Newcastle, New South Wales, in 2011, represents the most widespread outbreak of Tamiflu-resistant H1N1, and generated significant concern that these strains may spread outside Australia. - The Independent