U.S. influenza activity was still elevated during the week ending Jan. 1, and "the proportion of deaths attributed to pneumonia and influenza was above the epidemic threshold," according to officials at the U.S. Centers for Disease Control and Prevention (CDC).
The CDC found that 48 states reported widespread flu activity. Hawaii, Tennessee, the District of Columbia and Guam were the only jurisdictions reporting regional, local or no flu activity.
The CDC has 122 U.S. cities report on the proportion of deaths in their communities that seem to be the result of flu or pneumonia as a percentage of all deaths. The pneumonia and influenza mortality slice of mortality increased to 8.3 percent during the week ending Jan. 12. That's up from 7.2 percent during the previous week and an epidemic threshold of 7.3 percent.
Last week, the 7.3 percent proportion of deaths caused by pneumonia and flu was only slightly higher than the epidemic threshold of 7.2 percent for that week in the flu season cycle.
The percentage of outpatient visits that were related to flu-like illnesses fell during the week ending Jan. 12, to 4.6 percent, but the percentage was still comparable to the percentages reported during some weeks during the 2009-2010 pandemic and the moderately severe flu seasons that occurred in 2003-2004 and 2007-2008, officials said.
One possible sign that the current strain of flu might be particularly tough on children: About 41 percent of the children admitted to the hospital with laboratory-confirmed flu, up from 25 percent during the comparable week in the 2011-2012 flu season.
The 2013-2014 flu season also seems to be hard on pregnant women. About 23 percent of the adults admitted with the flu during the week ending Jan. 12 were pregant, up from 4.8 percent a year earlier.
For adults who are not pregnant, the percentage of flu admissions involving no known chronic condition fell to 7.7 percent, from 21 percent.