# US influenza activity and early mortality

> Live situation record from CLSTR: https://clstr.news/situations/us-influenza-activity-and-early-mortality
> Updated: 2026-10-18T12:10:48.000Z. Sources: 6. Developments: 2.

The 2026-27 influenza season has seen early reports of mortality and rising respiratory illness activity in the United States.

In early October, San Francisco health officials reported the city’s first influenza-related death of the season, involving an adult. At that time, the California Department of Public Health had recorded 26 flu-related deaths across the state, despite the CDC noting that national respiratory virus activity remained very low.

By mid-October, Colorado officials confirmed the first pediatric flu death of the season, involving an elementary school-aged child. Health officials in Colorado reported that flu activity was appearing approximately three weeks ahead of the typical schedule, with Flu A driving an increase in statewide hospitalizations. In Pitkin County, wastewater samples also indicated a sharp rise in COVID-19 cases during the late summer.

## Timeline

### 2026-10-18: Colorado reports first pediatric flu death amid early respiratory virus surge

Colorado has confirmed its first pediatric flu death of the 2026–27 season amid reports of an unusually early rise in flu and COVID-19 activity across the state.

2 sources. https://clstr.news/cluster/colorado-reports-first-pediatric-flu-death-amid-early-respiratory-virus-surge

### 2026-10-02: San Francisco reports first flu death of the 2026-27 season

San Francisco has recorded its first flu-related death of the 2026-27 season, involving an adult. Health officials are urging residents to stay updated on respiratory virus vaccinations.

4 sources. https://clstr.news/cluster/san-francisco-reports-first-flu-death-of-the-2026-27-season

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Cite as: US influenza activity and early mortality. CLSTR, https://clstr.news/situations/us-influenza-activity-and-early-mortality