Super flu causes fevers lasting up to seven days, doctors warn

Doctors report a fast-spreading H3N2 subclade K linked to higher fevers lasting up to seven days, and CDC data show very high illness levels in 32 states.

Health officials and clinicians report a fast-spreading influenza A H3N2 subclade called K is circulating widely across the United States. Doctors say this season is showing higher fevers that can persist for about five to seven days and some patients are experiencing intensified respiratory and gastrointestinal symptoms. Public health data and hospital reports indicate elevated illness levels and increased admissions in several areas. What is known: - CDC data are reported as showing "very high" respiratory illness activity in 32 states. - Most recent samples are influenza A, with a large share identified as H3N2 and many of those belonging to subclade K. - Clinicians have reported fevers lasting about five to seven days and more severe symptoms in some patients, including respiratory and gastrointestinal issues. - Reporting notes at least nine children have died this season and hospitals in some regions are experiencing higher admissions. Summary: Hospitals and clinicians are reporting a surge in H3N2 K cases with longer fevers and higher test positivity, which has increased pressure on emergency and pediatric services. Undetermined at this time.