It's not just adults 65 and older. Americans of all ages have faced serious health complications amid the new coronavirus outbreak, a federal health report says.

New data from the Centers for Disease Control and Prevention show that among the roughly 12% of COVID-19 cases in the U.S. known to need hospitalizations, about 1 in 5 were among people ages 20 to 44.

The CDC report released Wednesday tracked the health outcomes from February 12 to March 16 for the 2,449 COVID-19 patients in the U.S. whose ages were known.

Health officials have warned that older adults and people with underlying medical conditions face a higher risk of complications due to COVID-19, the disease caused by the new coronavirus.

The data still indicates older Americans face a higher risk of hospitalization, admission to an intensive care unit or even death.

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However, that doesn't mean younger Americans will not face serious health outcomes, either, the report shows.

Anywhere from 14% to 21% of adults ages 20 to 44 with COVID-19 have been hospitalized, the CDC data estimates. Two to 4% of cases led to ICU admissions, and less than 1% were fatal.

"This virus is impacting the entire population, and it's something the entire population should be responding to," Dr. Wayne Tsuang, a pulmonary and critical care physician at the Cleveland Clinic told USA TODAY.

The data set the CDC used is limited and does not account for underlying medical conditions. Many more young adults could have COVID-19 with mild symptoms not requiring hospitalization and without their cases being tracked by public health officials.

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Tsuang said more data collection is needed to better understand the risks younger people face. The data may overestimate the prevalence of severe disease, the report says, because testing has skewed toward those with travel histories or more serious symptoms.

Still, a hospitalization can have long-term effects on young people. Those hospitalized with COVID-19 will likely be isolated for many days and away from school or work, Tsuang said, not to mention the serious symptoms they're facing that caused their hospitalization.

"It takes a while for a patient to fully recover after a hospitalization," he said. "A hospitalization for this virus is very impactful, particularly for a young person."

The CDC report also underscores a warning from Dr. Deborah Birx, the White House’s coronavirus response coordinator.

"There are concerning reports coming out of France and Italy about some young people getting seriously ill, and very seriously ill in the ICUs," Birx said a news conference Wednesday.

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Birx said younger adults taking fewer precautions may have gotten sick as they saw early reports from China and South Korea showing mostly older people and those with underlying conditions affected.

"(Within) the millennial generation ... there may be a disproportional number of infections among that group. And so even if it's a rare occurrence, it may be seen more frequently in that group and be evident now," she added.

Of the 2,449 cases the report analyzed, 508 have resulted in hospitalizations, including 121 patients known to have been admitted to an intensive care unit.

Cases of ICU admission remained low among younger people. Those ages 20 to 44 made up only 12% of ICU cases. There were no ICU cases among people under 19.

Deaths were also low for younger people. Only nine of the 44 known deaths in the report were among those between ages 20 and 64, and no one under 19 was known to have died.

The report also highlighted the serious risks older Americans face. Between 10% and 27% of cases among people over 85 were fatal. People ages 75 to 84 saw up to 31% of cases leading to ICU admissions and up to 11% of cases being fatal. Similarly, for people between ages 65 and 74, up to 19% of cases led to ICU admissions and up to 5% were fatal.

Public health officials have stressed for younger people to better practice social distancing by staying away from large gatherings and staying home if they feel sick.

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Preliminary research has suggested that those with the virus can infect others before becoming symptomatic, posing a particular risk for older Americans who interact with young people who may feel no symptoms.

Photos on social media have shown spring breakers in Florida still partying on beaches or young adults out at bars and restaurants.

"We cannot have these large gatherings that continue to occur throughout the country for people who are off work, to then be socializing in large groups and spreading the virus," Birx said Wednesday. "You have the potential then to spread it to someone who does have a condition that none of us knew about and cause them to have a disastrous outcome."

Follow USA TODAY's Ryan Miller on Twitter @RyanW_Miller