CDC: Flu season continuing its decline

SATURDAY, March 31, 2018 -- Spring continues to take the bite out of this year's brutal flu season, new numbers show.

For starters: yet another drop was seen in doctor visits, and less severe strains of influenza are becoming ever more dominant.

But hospitalizations for the flu are still a problem, and there have been additional pediatric deaths, the latest federal numbers show.

For the seventh 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 24, the CDC said, 2.5 percent of patient visits to doctors were for the flu, down from 2.7 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 24, influenza B infections accounted for 58 percent of cases, while influenza A infections accounted for 42 percent. For the entire season so far, influenza A strains have been responsible for 70 percent of all cases, the CDC report noted.

Meanwhile, flu-linked hospitalization rates continue to rise -- from 93.5 per 100,000 people for the week ending March 17, to 96.1 per 100,000 people for the week ending March 24, the CDC data showed.

Pediatric flu deaths are also still increasing slightly, with an additional four deaths reported for the week ending March 24. That brings the season's total to 137.

CDC officials have pinpointed one reason why this flu season has been so tough: the flu vaccine has been 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 has been 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 30.

More information

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