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Posted by on Sep 17, 2009 in Epidemiology, Infectious diseases

CDC: More Than 1 Million Americans Infected to Date With Pandemic H1N1

CDC: More Than 1 Million Americans Infected to Date With Pandemic H1N1


It’s all swine flu all the time. Here’s the latest from the CDC by way of the MMWR.

  • Estimated, cumulative number of pandemic H1N1 infections in the United States between April and June: more than 1 million. (See yesterday’s post, for example, for how the estimated case number affects the estimated mortality rate.)
  • Peaks of activity: May and June nationwide; late August in the Southeast.
  • Confirmed H1N1 hospitalization rate from April to August: generally lower than that for seasonal influenza but higher than usual for the time period.
  • In-hospital death rate from mid-April to August 30th: 6.5% (593/9079); proportion of deaths due to pneumonia and influenza “within the bounds” of summertime expectations.
  • Circulating virus: 97% pandemic H1N1 that is sensitive to antiviral treatment.
  • Antiviral drug sensitivity: 99.4% of 1372 tested samples are susceptible to oseltamivir (Tamiflu; Roche); oseltamivir-resistant viruses still susceptible to zanamivir (Relenza; GSK); all viruses resistant to amantadine and rimantadine.
  • Recommendations for persons with influenza-like illness (ILI): after afebrile (untreated), stay home for another 24 hours.
  • Antiviral treatment recommendations: early therapy for persons with severe ILI and those individuals with suspected ILI and risk factors for complications (<5 years of age; >64 years of age; or underlying health conditions, including pregnancy).
  • Vaccines for seasonal influenza: available now and urged for all children, persons 50 years of age or older, and those at greater risk for influenza-related complications.
  • Vaccines for pandemic H1N1: still expected by mid-October; first in line have already been designated by the CDC.

Depiction of H1N1 virus from Wikipedia.

bmartin (1127 Posts)

A native East Tennessean, Barbara Martin is a formerly practicing, board-certified neurologist who received her BS (psychology, summa cum laude) and MD from Duke University before completing her postgraduate training (internship, residency, fellowship) at the Hospital of the University of Pennsylvania in Philadelphia. She has worked in academia, private practice, medical publishing, drug market research, and continuing medical education (CME). For the last 3 years, she has worked in a freelance capacity as a medical writer, analyst, and consultant. Follow Dr. Barbara Martin on and Twitter.