FLU NEWS SCAN: Australia's flu surge, IV zanamivir in H1N1 patients

Aug 16, 2011

Australia sees continued high flu levels
Flu activity in Australia continues to increase, with rising case numbers not confined to Queensland, New South Wales, and South Australia states, which have been the hot spots over the past several weeks, according to a report today from the country's Department of Health and Aging. Its latest surveillance report covers the week ending Aug 5. Most virus detections have been the 2009 H1N1 strain, but influenza B is circulating and has been dominant in some areas, such as Tasmania. Flu activity in four areas—Australian Capital Territory, New South Wales, Queensland, and Tasmania—has surpassed 2010 peaks. Nationally, the weekly number of confirmed cases is above annual peaks for previous years, except for 2009. The health department said the reason for the unusually high activity isn't clear, but the numbers don't appear to be only a reflection of increased testing. The flu season in the Southern Hemisphere typically runs from May through October.
Aug 16 Australian flu surveillance report

Study finds little IV zanamivir benefit in gravely ill H1N1 patients
A retrospective review of intravenous (IV) zanamivir (Relenza) treatment in Dutch patients who were admitted to intensive care units (ICUs) for severe 2009 H1N1 infections found that the drug had limited benefits, according to an early online study from the Journal of Infectious Diseases. During the pandemic, 26 patients received IV zanamivir treatment, but only 13 met the study's inclusion criteria. All had been treated with oseltamivir (Tamiflu) earlier in their illness, and four had strains that resisted the drug. Researchers gauged IV zanamivir's effects by comparing viral loads around the time of treatment with later levels. They found a sustained reduction in viral load in 6 of 13 patients and determined that this was associated with earlier treatment. But the reduction in viral load did not affect mortality, as 3 of the 6 patients with sustained reductions died. Several factors could have influenced the response to IV zanamivir, such as the high proportion of immunocompromised patients and poor response to oral oseltamivir. The report says it's unclear if zanamivir resistance played a role. Studies are needed to assess earlier IV zanamivir monotherapy or use of the IV formulation in combination withother treatment strategies, the investigators concluded.
Sep 1 J Infect Dis abstract