Swine Flu Becoming More Resistant To 'Tamiflu,' Scientists Say

Swine flu is becoming more resistant to Tamiflu, prompting worry over the world's ability to fight the virus.

The swine flu appears to be more prone to developing drug resistance than other types of flu, said Dr. Aeron Hurt from the World Health Organization collaborating center for flu research in Melbourne, Australia.

Research on patients in Newcastle, New South Wales, Australia in 2011 found that only one person in the study had used Tamiflu but that a resistant form of the virus spread to 20 percent of all those who developed swine flu in the region.

The seeming ease of transfer of Tamiflu resistant strains of swine flu will alarm public health officials, The Guardian reported.

"Sustained global monitoring for the emergence of resistance is important to underpin public health and guidance for clinical management. Surveillance schemes should assess frequency of resistance in the community and in specific patient groups receiving treatment, such as severely immunocompromised, seriously ill patients in hospital, and patients not responding to antiviral therapy," said Hurt.

While only two percent of the world's strains of swine flu are resistant to Tamiflu, the researchers found mutations in all strains of the swine flu, which reportedly suggests that the virus can develop resistance to antiviral drugs.

Researchers found that one in five cases of swine flu in one area of Australia were resistant to Tamiflu.

Dr. Hurt warned that access to anti-viral treatments may have to be restricted to limit further resistance developing.

Tamiflu resistance develops when a patient receives received the drug to control symptoms of the virus. In most flu viruses, the changes that make the virus resistant to treatment also make it less likely to spread to others. IN the case of the swine flu, that has not happened, and the virus remains able to spread to others, Hurt said.

Tamiflu, also sold under the generic name oseltamivir, is one of few effective treatments of pandemic swine flu.