This report contains data from the Centers for Disease Control and Prevention 2012/2013 Influenza season week 12 for the period ending March 23, 2013. In this reporting period (March 17-23, 2013) influenza continues a lingering goodbye as the season begins to change.
Accounting for 72% of all influenza cases reported during this period, influenza B virus is now the most prevalent strain according to the CDC.
The number of hospitalizations reported this period was 41.8 and up slightly from last weeks number of 40.6 per 100,000 population. Those greater than 65 years of age account for 50% of those hospitalized. Influenza and pneumonia related deaths are now reported to be at the epidemic threshold.
Michigan is the only state to report high ILI activity (down from nine states in previous report) with five other states reporting moderate activity. Six states and NYC report low ILI activity while thirty-eight states now report minimal activity.
Viral surveillance results for week 13, 2013 showed 13.2% of 702 samples samples testing positive for influenza as compared to last week when 16.3% of 5,526 samples were positive. Influenza A accounted for 26.5% of results with 2009 H1N1 5.9%, H3 32.8%, and Influenza B 73.5% of circulating flu.
Outpatient ILI surveillance (those seen at clinics and doctors offices for ILI complaints) remains at the national base line of 2.2% for the second week in a row. The CDC adds:
Three of 10 regions reported ILI at or above region-specific baseline levels. One state experienced moderate activity; 3 states and New York City experienced low activity; 46 states experienced minimal activity, and the District of Columbia had insufficient data.Antiviral resistance is a non-issue at this point. None of the circulating strains (H1N1, H3N2 or Influenza B) are resistant to Oseltamivir or Zanamivir.
State-by-State week 12 reporting (from CDC website)
- Widespread influenza activity was reported by 6 states (Connecticut, Massachusetts, Nevada, New Jersey, New York, and North Carolina).
- Puerto Rico and 8 states reported regional influenza activity (Alaska, Kentucky, New Hampshire, Ohio, Oklahoma, Oregon, Pennsylvania, and Virginia).
- The District of Columbia and 23 states reported local influenza activity (Alabama, Arizona, Arkansas, California, Georgia, Idaho, Illinois, Iowa, Louisiana, Michigan, Minnesota, Missouri, Montana, Nebraska, North Dakota, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, West Virginia, Wisconsin, and Wyoming).
- Eleven states reported sporadic influenza activity (Colorado, Florida, Hawaii, Indiana, Maine, Maryland, Mississippi, New Mexico, Utah, Vermont, and Washington).
- Guam and one state (Kansas) reported no influenza activity.
- The U.S. Virgin Islands and one state (Delaware) did not report.
CDC Flu Interactive Map
|Click for Week 11 interactive map from CDC|
Google Flu Trends