A box of masks is shown in the emergency room at Palomar Medical Center in Escondido, California, U.S., January 18, 2018. REUTERS/Mike Blake

(Reuters) - One of the worst flu outbreaks in the United States in nearly a decade worsened last week and will likely linger for several weeks, causing more deaths, the Centers for Disease Control and Prevention said on Friday.

Another 10 children were reported to have died of the flu in the week ending Feb. 3, bringing the total infant mortality so far this season to 63, Dr. Anne Schuchat, the CDC’s acting director, told reporters. The CDC does not require national reporting of flu deaths in adults.

“I wish there were better news this week, but almost everything we’re looking at is bad news,” Schuchat said. “There have been far too many heart-wrenching stories in recent weeks about families who have lost loved ones to influenza.”

It was unclear whether the outbreak had reached its peak yet or if it would get worse, she said. Previous outbreaks had lasted between 11 and 20 weeks, and the current outbreak was in its 11th week, she said.

The number of people hospitalized for flu-like illnesses is the highest the CDC has seen since starting its current tracking system in 2010.

The dominant flu strain this season, influenza A (H3N2), is especially potent, linked with severe disease and death, particularly among children and the elderly.

The outbreak has reached almost every corner of the country, with every state except Hawaii and Oregon reporting widespread flu, Schuchat said.

She urged sick people to stay home and said it is still not too late for people to get a flu vaccine, which offers some protection.