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 37: During week 37, influenza diagnoses at local emergency departments remained low. Detections for influenza A and influenza B at select local hospital laboratories remained low during week 37, consistent with the past several weeks. Data from all facilities are complete from Week 8 2025 forward. Thirty-six influenza outbreaks in long-term care facilities have been reported and confirmed (≥ 1 case of laboratory confirmed flu reported in a long-term care facility) during the 2024-2025 season.

Week 37 Report: Click here to download the latest weekly report of influenza activity (September 7, 2025, through September 13, 2025) in a printable format.

State and National Influenza Surveillance Updates:

Pennsylvania: As of September 13, 2025, the Pennsylvania Department of Health (PADOH) respiratory virus summaries remain paused due to low activity. Activity levels in PA are based on laboratory confirmed influenza cases. For more information, please visit: https://www.pa.gov/en/agencies/health/diseases-conditions/infectious-disease/respiratory-viruses/respiratory-virus-dashboard.html.

United States: As of September 13, 2025, the CDC reported that influenza activity remains low. In week 37, clinical laboratories reported 145 (0.4%) of 41,304 specimens tested positive for influenza, 90.3% of which were influenza A. Of influenza A specimens subtyped at public health labs, 50.0% have been subtyped as H1N1. In week 37, 55 jurisdictions with sufficient data reported minimal activity. Activity levels were calculated from outpatient data reported to ILINet. For more information, please visit: https://www.cdc.gov/fluview/surveillance/2025-week-37.html.