Influenza activity is increasing across the United States, with early-season surveillance data showing rising test positivity, outpatient visits for influenza-like illness and influenza-associated hospitalizations, according to the Centers for Disease Control and Prevention (CDC).

In its FluView report for the week ending October 10, 2026, the CDC reported that 5.0% of specimens tested for influenza by clinical laboratories were positive, up from 3.9% the previous week. Of 45,331 specimens tested during the week, 2,270 were positive.

Outpatient visits for influenza-like illness (ILI) also increased. The CDC’s Outpatient Influenza-like Illness Surveillance Network reported that 2.1% of patient visits were associated with ILI, defined as fever accompanied by cough or sore throat. Although the percentage was higher than the previous week, it remained below the national baseline of 2.9%.

ILI surveillance captures visits for respiratory illnesses that may be caused by influenza or other pathogens; it does not represent laboratory-confirmed influenza cases. The CDC recommends interpreting these data alongside other surveillance indicators.

Influenza A accounted for the majority of positive specimens. Among the 300 influenza viruses reported by public health laboratories during week 40, 292 were influenza A and eight were influenza B. Of the 251 influenza A viruses subtyped, 96.4% were A(H1N1)pdm09 and 3.6% were A(H3N2).

Hospitalization indicators also showed signs of increasing activity. The CDC’s Influenza Hospitalization Surveillance Network reported 256 laboratory-confirmed influenza-associated hospitalizations at participating sites during the week ending Oct. 10. The estimated weekly hospitalization rate, adjusted for reporting delays, was 1.2 per 100,000 population.

Despite these increases, the CDC characterized overall seasonal influenza activity as low, with the highest activity occurring along the West Coast. The agency noted that early-season activity was higher than typically observed at this point in the year but remained within expected seasonal variation.

The CDC’s influenza surveillance data are preliminary and may change as additional reports are received. Clinical laboratories and healthcare organizations can use the agency’s FluView Interactive dashboard to explore influenza trends by season, geographic region and state.