On Jan. 3, 2025, the Centers for Disease Control and Prevention (CDC) reported that during Christmas week, respiratory virus activity continued a steady rise across much of the nation, with the largest spikes seen for flu. COVID-19 levels continue to climb from low levels, and respiratory syncytial virus (RSV) activity is still very high in many regions.

Emergency department (ED) visits for flu and RSV are very high, with the steepest rise for flu. For COVID, ED visits are highest among young children and older adults. Flu hospitalizations continue a steep rise compared to the other two viruses, coming in at 7.8 per 100,000 hospitalized people, roughly twice the level as for COVID, according to data from the CDC’s National Healthcare Safety Network.

Flu is also leading the other two viruses for test positivity, rising from 12.0% to 18.7% compared to the previous week. For comparison, COVID test positivity has risen to 7.0%, with the level for RSV at 12.7%. The percentage of outpatient visits for flulike illness also saw a jump last week, up from 4.9% to 6.8%. Flu is at the high or very high level across 42 states, with the highest levels across the South, Southwest, and part of the Northwest, including Idaho and Oregon.