America's current flu season appears to be waning, as the latest CDC data shows no states experienced widespread flu activity in the week ending on April 18.

Flu activity so far

Approximately 39 million to 56 million people were sickened with the flu between Oct. 1, 2019, and April 4, 2020, according to CDC's last in-season influenza burden estimate for this flu season.

Friday's Weekly Influenza Surveillance report from CDC shows that nine states were experiencing regional flu activity during the week ending on April 18, while 12 states were experiencing local flu activity; 26 states and Washington, D.C., were experiencing sporadic flu activity; and Delaware, New Mexico, and Rhode Island reported no flu activity.

By some indicators, this flu season overall has been worse than last flu season. For example, CDC's latest report shows the cumulative hospitalization rate for the flu so far this season is 68.6 per 100,000 people, compared with 62.8 per 100,000 at the same point last season.

CDC estimated that this year's flu season led to at least 18 million medical visits, 410,000 hospitalizations, and 24,000 deaths from Oct. 1, 2019 to April 4, 2020.

But CDC also found that the percentage of outpatient visits for influenza-like illness decreased to 2.2% during the week ending on April 18, bring it below the national baseline of 2.4%. Still, CDC noted that four out of 10 regions in the United States were above the 2.4% baseline for outpatient visits for influenza-like illness in the week ending with April 18.

Worst flu season for children in a decade

This flu season has been especially bad for children, according to CDC. The latest CDC report shows 169 pediatric deaths were reported as of April 18, with one new pediatric death occurring in the week ending on April 18. The cumulative hospitalization rate for children ages four and under so far this season is 94.7 per 100,000 people.

Experts say the high number of pediatric deaths this flu season is due to the fact that both influenza A and B have been dominant, leading to what's being called a "double barrel" flu season. Experts say the influenza B strain is more likely to affect younger people, though they're not sure why. Some believe that older people may have some immunity to influenza B, as it doesn't mutate as much as other flu strains, meaning it's possible older people have caught the strain circulating this season before (CDC Weekly U.S. Influenza Surveillance Report, 4/24; CDC "Flu View," accessed 4/27; CDC Preliminary In-Season 2019-2020 Flu Burden Estimates, accessed 4/27; Schumaker, ABC News, 2/21; Wesner Childs, Weather.com, 2/14; Edwards, NBC News, 2/20).