This year’s flu season, which started a month earlier than usual, continues to show increased activity across the nation.
In week 50 (Dec. 9-15), 30% of the 9,500 respiratory specimens tested in national laboratories were positive for influenza. Among outpatient visits reported to the U.S. Outpatient Influenza-Like Illness Surveillance Network, 3.2% were positive for influenza-like illness, compared to the expected national baseline of 2.2%.
Over the last several weeks, the number of states reporting high flu activity grew from 5 to 12. Those states include Alabama, Georgia, Illinois, Louisiana, Mississippi, Missouri, North Carolina, Tennessee, Texas, Utah, and Virginia. Meanwhile, 22 states are still reporting minimal flu activity.
"It’s too early to tell how severe our season might be," CDC Director Dr. Thomas Frieden said in a statement. "However, we know that thousands die and hundreds of thousands of people are hospitalized with flu each year."
The proportion of deaths (6.7%) attributed to pneumonia and influenza are still below the epidemic threshold (7.0%) in week 50. Two pediatric deaths related to influenza were reported in week 50.
The dominant strain this year is influenza A(H3N2), which has been associated with more severe flu seasons. This year’s flu vaccine is a 90% match for the specimens that have been sent to the CDC, according to an agency update on Dec. 21.
Dr. Thomas R. Frieden
"Vaccination is the single most important step we can take to protect ourselves and our families against infection. It’s not too late to get vaccinated before the flu season peaks," Dr. Frieden said.
Roughly 123 million doses of influenza vaccine have been distributed so far, and nearly 112 million Americans have been vaccinated so far this flu season, the CDC reported.
Also on Dec. 21, the Food and Drug Administration expanded approval of oseltamivir (Tamiflu) to children as young as 2 weeks old who have shown flu symptoms for 2 days or less. The agency stressed that oseltamivir is not approved to prevent flu in this population and that the drug’s safety and efficacy has not been established in those younger than 2 weeks old.