CDC: Circulating influenza B viruses can cause severe illness

Editor's note:For the latest flu coverage, visit https://www.aappublications.org/collection/influenza.

Federal health officials are urging flu vaccination and prompt treatment with antivirals as influenza B/Victoria viruses circulate widely.

Influenza B viruses have been linked to high rates of pediatric deaths. So far this season, 32 children have died and 21 of those have been linked to influenza B.

Influenza A(H1N1)pdm09 viruses are the second most common this season and also can cause severe illness, according to an advisory from the Centers for Disease Control and Prevention (CDC).

Flu is widespread in 46 states and Puerto Rico, and activity is high in 33 states, Washington, D.C., New York City and Puerto Rico. The CDC estimates 9.7 million people have gotten sick, 87,000 have been hospitalized and 4,800 have died this season.

The CDC is recommending everyone 6 months and older get vaccinated against the flu. For those who get sick, four antiviral medications are approved by the Food and Drug Administration and detailed in the CDC’s health advisory.

Clinicians should start treatment as early as possible for patients with suspected or confirmed flu who are hospitalized, severely ill or at high risk for complications but are not hospitalized. Those high-risk groups include children under 2 years, adults 65 and older, women who are pregnant, American Indians, Alaska Natives, residents of nursing homes and people with chronic disorders, neurologic conditions, immunosuppression and extreme obesity.

For non-high-risk patients, antivirals can be prescribed within two days of illness onset. Clinicians should use their judgment and consider the patient’s age, disease severity and time since onset.