Deaths in the current flu season have officially crossed the line into “epidemic” territory, federal health officials said Friday, adding that, on the bright side, there were also early signs that the caseloads could be peaking.
Officials from the Centers for Disease Control and Prevention, speaking on a telephone news conference, again urged Americans to keep getting flu shots. At the same time, they emphasized that the shots are not infallible: a preliminary study rated this year’s vaccine as 62 percent effective, even though it is a good match for the most worrisome virus circulating. That corresponds to a rating of “moderately” effective — the vaccine typically ranges from 50 percent to 70 percent effective, they said.
Even though deaths stepped — barely — into epidemic territory for the first time last Saturday, the C.D.C. officials expressed no alarm, and said it was possible that new flu infections were peaking in some parts of the country. “Most of the country is seeing a lot of flu and that may continue for weeks,” said Dr. Thomas R. Frieden, the C.D.C.’s director.
New outpatient cases — a measure based on what percentage of doctor visits were for colds or flu — dropped off slightly from the previous week, to 4 percent from 6 percent. The trend was more pronounced in the South, where this year’s season began.
Dr. Frieden cautioned that the new flu figures could be aberrations because they were gathered as the holiday season was ending. Few people schedule routine checkups then, so the percentage of visits for severe illness can be pushed artificially high for a week or two, then inevitably drop.
Deaths from pneumonia and the flu, a wavy curve that is low in summer and high in winter, typically touch the epidemic level for one or two weeks every flu season. How bad a season is depends on how high the deaths climb for how long.
So far this season, 20 children with confirmed flu tests have died, but that is presumably lower than the actual number of deaths because not all children are tested and not all such deaths are reported. How many adults die will not be estimated until after the season ends, said Dr. Joseph Bresee, the chief of prevention and epidemiology for the C.D.C.’s flu branch. Epidemiologists count how many death certificates are filed in a flu year, compare the number with normal years, and estimate what percentage were probably flu-related.