Health Information Portal (HIP)

Philadelphia Influenza Surveillance Updates: PDPH tracks influenza activity in Philadelphia, especially severe influenza disease. Providers should report all hospitalized influenza cases, influenza deaths in children, and influenza outbreaks in closed settings like long-term care facilities and shelters.

Week 49: During week 49, influenza diagnoses at local emergency departments increased for all age groups, particularly for adults. Positive detections for influenza A at select local hospital laboratories also increased, while detections for influenza B remained low during week 49. One influenza outbreak in a long-term care facility has been reported and confirmed (≥ 1 case of laboratory confirmed flu reported in a long-term care facility) during the 2025-2026 season to date.

Week 49 Report: Click here to download the latest weekly report of influenza activity (November 30 - December 6, 2025) in a printable format.

State and National Influenza Surveillance Updates:

Pennsylvania: As of December 6, 2025, the Pennsylvania Department of Health (PADOH) respiratory virus summaries currently list influenza activity as low but increasing rapidly. Activity levels in PA are based on laboratory confirmed influenza cases. For more information, please visit: https://www.pa.gov/agencies/health/diseases-conditions/infectious-disease/respiratory-viruses/respiratory-virus-dashboard.

United States: As of December 6, 2025, the CDC reported that influenza activity is increasing. In week 49, clinical laboratories reported 4,790 (8.1%) of 59,364 specimens tested positive for influenza, 94.5% of which were influenza A. Of influenza A specimens subtyped at public health labs, 86.0% have been subtyped as H3N2 and 14.0% have been subtyped as H1N1. In week 49, 41 jurisdictions with sufficient data reported minimal to low levels of activity, including low activity reported in Pennsylvania. Additionally,13 jurisdictions reported moderate to high activity, including high activity in both New York State and New Jersey. New York City was the only jurisdiction to report very high activity during week 49. Activity levels were calculated from outpatient data reported to ILINet. For more information, please visit: https://www.cdc.gov/fluview/surveillance/2025-week-49.html.