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 12: Influenza diagnoses at local emergency departments decreased for all age groups during week 12. Positive detections of influenza A at select local hospital laboratories continued to decrease during week 12 following the seasonal peak. Detections for Influenza B continued to increase during week 12. Data from all facilities are complete from Week 8, 2025 forward. Twenty-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) so far this season.

Week 12 Report: Click here to download the last weekly report of influenza activity (March 16, 2025 through March 22, 2025) in a printable format.

State and National Influenza Surveillance Updates:

Pennsylvania: As of March 22, 2025, the Pennsylvania Department of Health (PADOH) reported that Influenza activity is high but continues to decrease. 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 March 22, 2025, the CDC reported that influenza activity continues to decline nationally. In week 12, clinical laboratories reported 8,358 (10.7%) of 78,062 specimens tested positive for influenza, 59.4% of which were influenza A. Of influenza A specimens subtyped at public health labs, 52.2% have been subtyped as H1N1 and 47.8% as H3N2. In week 12, 7 jurisdictions reported high levels of influenza activity. The remaining 46 jurisdictions with sufficient data reported minimal to moderate activity, including low activity reported in Pennsylvania and moderate activity reported in New Jersey. Activity levels were calculated from outpatient data reported to ILINet. For more information, please visit: https://www.cdc.gov/fluview/surveillance/2025-week-12.html.