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 20: Influenza diagnoses at local emergency departments and positive detections of influenza A at select local hospital laboratories remained low. Detections for influenza B further decreased during week 20, consistent with the past several weeks. Data from all facilities are complete from Week 8 2025 forward. Twenty-nine 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) so far this season.

Week 20 Report: Click here to download the last weekly report of influenza activity (May 11, 2025 through May 17, 2025) in a printable format.

State and National Influenza Surveillance Updates:

Pennsylvania: As of May 17, 2025, the Pennsylvania Department of Health (PADOH) reported that influenza activity is low. 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 May 17, 2025, the CDC reported that influenza activity remains low. In week 20, clinical laboratories reported 892 (2.4%) of 37,530 specimens tested positive for influenza, 25.6% of which were influenza A. Of influenza A specimens subtyped at public health labs, 54.3% have been subtyped as H1N1 and 45.7% as H3N2. In week 20, all 55 jurisdictions with sufficient data reported minimal influenza activity. Activity levels were calculated from outpatient data reported to ILINet. For more information, please visit: https://www.cdc.gov/fluview/surveillance/2025-week-20.html.