Seasonal influenza places a significant burden on healthcare systems each year, and the timing, intensity, and age distribution of flu seasons can vary considerably.1 Understanding how influenza affects different age groups helps inform vaccination campaigns, clinical preparedness, and public health messaging.
To increase understanding of age-group-specific trends in influenza and other communicable diseases, we updated the Communicable Diseases Data Tracker to include age group breakdowns: under 2, 2–4, 5–17, 18–49, 50–64, and 65 and older. The data tracker shows weekly rates of communicable disease diagnoses or positive labs per 100,000 patients with office visits, emergency department visits, or admissions across more than 300 healthcare organizations.
This season’s influenza peak was notably higher than the prior two seasons, but the increase was not evenly distributed across age groups. Children and older adults saw the sharpest rise, while middle-aged adults were largely unaffected. Among all age groups, children experienced the highest peak visit rates, rising to 90% higher than the 2023–24 season. Adults aged 65 and older also saw a marked increase, with peak rates 56% above the 2023–24 season. By contrast, adults aged 50–64 showed virtually no change across all three seasons, and adults aged 18–49 saw only a moderate increase.
