ATLANTA — Influenza activity remained low nationally but was rising across several measures in the latest weekly surveillance report from the Centers for Disease Control and Prevention.
The FluView report, published Oct. 16 and covering the week ending Oct. 10, found that 5% of specimens tested by participating clinical laboratories were positive for influenza, up from 3.9% the previous week. That is an increase of 1.1 percentage points.
Clinical laboratories reported 2,270 positive specimens among 45,331 tested during the reporting week. Influenza A accounted for 2,222 positives, while influenza B accounted for 48. Those are laboratory specimen counts, not a count of every person infected in the United States.
The CDC said outpatient visits for influenza-like illness, emergency department visits with an influenza diagnosis and laboratory-confirmed flu hospitalizations had also been increasing since late August or early September. The agency identified the highest activity along the West Coast.
Different parts of the surveillance system answer different questions. Clinical laboratory positivity helps track changes in activity, while public health laboratories help identify circulating virus types and subtypes. Outpatient illness monitoring includes symptoms that can have causes other than influenza.
All figures in the report are preliminary and can change as additional reports arrive. The national findings do not establish the level of flu activity in St. Louis or describe conditions on Oct. 20 itself; the reporting period ended 10 days earlier.
Sources: CDC FluView: Week 40, ending October 10, 2026; CDC influenza surveillance purpose and methods.
