Tamiflu-resistant swine flu is here

A kidney transplant patient in WA has died after developing Australia’s first case of H1N1 pandemic influenza resistant to oseltamivir (Tamiflu).
However, the virus still appears to be to be sensitive to zanamavir (Relenza) says Dr David Speers, Infectious Diseases Physician at the Sir Charles Gairdner Hospital in Perth, in a case report in the MJA today.  
Dr Speers and colleagues say their patient initially became infected with wild-type H1N1 influenza after undergoing a renal transplant and while taking immunosuppressant drugs.  
After a 10-day course of oral oseltamivir the patient developed rapid-onset severe primary viral pneumonia due to oseltamivir-resistant virus, and respiratory failure progressed despite high-dose oral oseltamvir and nebulised zanamivir.  
The patient improved and became negative for influenza after being treated with intravenous zanamavir but subsequently died from intraperitoneal sepsis.  
The report’s authors say the resistant virus contained the H275Y NA mutation, which is the major mechanism for oseltamivir resistance in influenza. Until now most of the 31 cases of resistance reported worldwide have occurred in people taking oseltamivir as post-exposure prophylaxis, they note.  
They say the patient developed the resistant strain a few days after stopping his initial course of oseltamivir, “possibly due to declining blood and tissue levels of the antiviral drug”.  
They conclude by saying that intravenous zanamivir may prove to be a useful antiviral therapy for severely unwell influenza patients, including those with oseltamivir-resistant pandemic (H1N1) 2009 infection.