CDC officials on Friday announced that 7.3% of deaths reported in the United States last week were caused by pneumonia or flu, pushing the illness past the "epidemic" threshold.
However, officials noted that there are signs that the "caseloads could be peaking."
Nine out of the 10 U.S. regions are experiencing "elevated" flu activity as of Jan. 5, with only a handful of states reporting "normal" flu activity, CDC reported. According to the agency's weekly update, flu activity as of Jan. 5 was widespread in 47 states, up from 41 states in the previous week.
CDC noted that the number of states with high levels of influenza-like illness declined to 24, from 29 in the previous week, with more states reporting moderate flu-like illness.
However, CDC Director Thomas Frieden cautioned that the flu data could contain outliers because they were collected at the end of the holiday season, when few people schedule visits to their doctor. As a result, the percentage of visits for severe illness might be "pushed artificially high for a week or two, then inevitably drop," according to the New York Times.
Frieden said, "The bottom line is, it's flu season, and most of the country is seeing influenza activity or has seen it and it may continue for a number of weeks."
Shots offer 'moderate' protection, CDC finds
In related news, this year's flu vaccine has been rated "moderately" effective, at 62%, according to a month-long CDC survey of 1,155 children and adults that ended on Jan. 2.
The findings are comparable with the effectiveness of flu vaccines in previous years.
Frieden noted, "The flu vaccine is far from perfect, but it's still by far the best tool to fight the flu," adding that getting vaccinated means "you're 62% less likely to be treated for the flu" (Begley, Reuters, 1/11; McNeil, New York Times, 1/11; Sun, Washington Post, 1/11; Martin, Wall Street Journal, 1/11).