By: Helen Branswell

TORONTO — American scientists have reported the first known case of H1N1 viruses that are resistant to the newest flu drug to hit the market, peramivir.

The case involved a person with H1N1 flu who first developed resistance to oseltamivir or Tamiflu. Because of similarities in the drugs’ chemical structures, it was expected that viruses resistant to Tamiflu would be resistant to the new drug as well.

But the confirmation makes it clear doctors treating severely ill flu patients need to try to maximize the benefits of the few flu drugs available and minimize the risk of resistance developing, said Dr. Matthew Memoli, a physician and researcher at the National Institute of Allergy and Infectious Diseases and first author of the report.

Memoli suggested doctors can do that by giving more thought to the order in which they use flu drugs when treating seriously sick patients or those who seem at risk of becoming gravely ill because they suffer from other medical conditions.


•  Brazil reports 36 A/H1N1 flu deaths so far this year (Link)

•  First A/H1N1 flu case detected in Chile’s earthquake devastated zone (Link)

•  Drought may prompt Tamiflu producer to replace major ingredient (Link)

•  Myanmar says new influenza A/H1N1 still strikes 8 townships (Link)

United States
•  US: CIDRAP – CDC sees sustained H1N1 activity in Southeast (Link)
•  US: CIDRAP – Researchers report peramivir-resistant H1N1 case (Link)

•  WHO: Pandemic (H1N1) 2009 – update 93 (Link)

•  Recombinomics: Transmission Linked To Rapid Appearance of Tamiflu Resistance (Link)