During week 5 (January 27 – February 2, 2013), influenza activity remained elevated in the United States, but decreased in most areas.  To give you some perspective, during week 2 (January 6-12), 48 states reported widespread geographic influenza activity.  Here is the break down for week five.


  • Geographic Spread of Influenza: Thirty-eight states reported widespread influenza activity; 9 states reported regional influenza activity; the District of Columbia, Puerto Rico and 2 states reported local influenza activity; one state reported sporadic influenza activity; Guam reported no influenza activity, and the U.S. Virgin Islands did not report.
  • Viral Surveillance: Of 10,132 specimens tested and reported by collaborating laboratories, 2,362 (23.3%) were positive for influenza.
  • Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was above the epidemic threshold.
  • Influenza-Associated Pediatric Deaths: Fourteen pediatric deaths were reported.
  • Influenza-Associated Hospitalizations: A cumulative rate for the season of 29.8 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported. Of all hospitalizations, more than 50% were among adults 65 years and older.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 3.6%. This is above the national baseline of 2.2%. All 10 regions reported ILI above region-specific baseline levels. Nineteen states and New York City experienced high ILI activity; 12 states experienced moderate activity; 13 states experienced low activity; 6 states experienced minimal activity; and the District of Columbia had insufficient data.