WASHINGTON - VIRTUALLY all cases of the most common strain of flu circulating in the United States now resist the main drug used to treat it, the US Centres for Disease Control and Prevention reported on Monday.
CDC researchers said 98 per cent of all flu samples from the H1N1 strain were resistant to Roche AG's Tamiflu, a pill that can both treat flu and prevent infection. Four patients infected with the resistant strain have died, including two children.
YOUNG PATIENTS
DR NILA Dharan's team interviewed 99 patients and found 30 per cent of them had been vaccinated against flu but became infected anyway. The vaccine is known not to fully protect against infection.
'Two patients died on the way to the hospital or in the emergency department. One patient was 4 years old and previously healthy, and one patient was 4 years old with neurological problems,' Dr Dharan's team wrote.
This year, H1N1 is the most common strain of flu in the United States, although the flu season is a mild one so far, and still below the levels considered an epidemic.
Few doctors even test patients for flu, and Tamiflu is not widely prescribed. But the news is sobering because the pill, known generically as oseltamivir, is one of the few weapons against influenza, which kills an estimated 36,000 people in the United States in an average year.
It is also considered a key weapon against a potential pandemic of a new type of influenza, and this study suggests the virus can rapidly evade its effects.
This season, nine children have died from influenza, most apparently healthy before they got infected, the CDC reports.
Last flu season, only 19 per cent of H1N1 viruses tested were Tamiflu-resistant, Dr Nila Dharan and colleagues at the CDC reported.
'As of February 19, 2009, resistance to oseltamivir had been identified among 264 of 268 (98.5 percent) US influenza A(H1N1) viruses tested,' the researchers wrote in the Journal of the American Medical Association. -- REUTERS
