Tough flu season finally slowing down, CDC says

FRIDAY, March 16, 2018 -- As winter nears its end so too does a tough flu season, with new data showing a decline in doctor visits and less severe strains of influenza beginning to dominate.

But hospitalizations for the flu remained a problem, and there have been additional pediatric deaths.

For the fifth week in a row, there was a decrease in the number of doctor visits for flu-like illness, the U.S. Centers for Disease Control and Prevention reported Friday.

As of March 10, the CDC said, 3.3 percent of patient visits to doctors were for the flu, down from 3.7 percent of patient visits the week before.

And, as health officials predicted, cases of less severe influenza B infections continue to be more common than cases of more severe influenza A infections.

For the week ending March 10, influenza B infections accounted for 53.5 percent of cases, while influenza A infections accounted for 46.5 percent. For the entire season so far, influenza A strains have been responsible for nearly 72 percent of all cases, the CDC report noted.

Meanwhile, flu-linked hospitalization rates continued to rise -- from 86.3 per 100,000 people for the week ending March 3, to 89.9 per 100,000 people for the week ending March 10, the CDC data showed.

Pediatric flu deaths are also still increasing slightly, with an additional nine deaths reported for the week ending March 10. That brings the season's total to 128.

CDC officials have pinpointed one reason why this flu season has been so tough: the flu vaccine is only 25 percent effective against the more severe H3N2 influenza, which caused most flu cases this year.

Among children aged 6 months through 8 years old, however, the vaccine's effectiveness is 59 percent, the agency reported.

Despite the poor match of the vaccine to the most common strain of flu, the CDC is still urging people who haven't gotten a flu shot to get one, because the vaccine is more effective against other types of flu.

For instance, the vaccine is 67 percent effective against the H1N1 flu, which was the 2009 pandemic flu and is still around. In addition, the vaccine is 42 percent effective against the influenza B viruses, which are also circulating widely, the researchers said.

The flu shot's overall effectiveness against all strains was pegged at 36 percent, the CDC said.

The CDC recommends that everyone aged 6 months and older get a flu shot.

The CDC's FluView update was published online March 16.

More information

The U.S. Centers for Disease Control and Prevention has more about the flu.