Seasonal Influenza in Philadelphia
Philadelphia Seasonal Influenza Activity:     
Number of Lab-Confirmed Reports: 8*
Number of Hospitalized Cases: 8**
Number of Deaths: 0
*Different surveillance systems are maintained for influenza. Only a subset of laboratories report positive influenza results.
**Reports not limited to facilities who participate in laboratory testing.

Last Updated (12/23/2020)

Current Recommendations
  • Annual influenza vaccine is recommended for ALL persons 6 months of age and older. Providers should offer influenza vaccination to all patients at every opportunity.
  • Healthcare worker influenza vaccination is recommended and endorsed by the Centers for Disease Control and almost every professional organization. Providers should be vaccinated to protect patients, themselves and their families.
  • Respiratory etiquette is also important during influenza season. Everyone should cover their cough and practice regular hand-washing, especially when symptomatic.
 Latest Updates on Seasonal Influenza
  • Influenza activity is currently characterized as LOW in Pennsylvania (influenza outbreaks or increases in influenza-like illness cases or laboratory-confirmed influenza in at least half of a state's regions).

Health Alerts, Advisories, Notifications, and Updates

New Influenza Vaccine Requirement for Daycare Attendees: The Board of Health in Philadelphia passed a new regulation requiring flu vaccination for all children 6 months – 5 years old who attend any group child care facility in Philadelphia. Child care attendees need to receive a flu vaccine every year between September 1st and December 31st.

Vaccine Information

  • Influenza vaccination is the most effective tool available to prevent illness due to influenza. Getting vaccinated reduces the risk of flu-related doctor's visits, hospitalization, and death.
  • Anyone can receive an age-appropriate influenza vaccine except infants <6 months of age and people with history of a severe, life-threatening allergic reaction to flu vaccine or any flu vaccine ingredient. Most people with egg allergies can receive flu vaccines.
  • Flu vaccine is especially important for people who are at higher risk of serious complications from influenza including children <5 years, adults 65 years and older, pregnant women and people who have:
    • Asthma and other chronic lung diseases
    • Diabetes
    • Metabolic disorders
    • Immunocompromising conditions (i.e., HIV/AIDS, cancer) or who take immunocompromising medicines
    • Neurologic conditions
    • Obesity
    • Blood disorders like sickle cell diseases
  • Providers should continue to give influenza vaccine as long as influenza is still circulating in the community.

Surveillance                                                                                                                           Archive

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: Febrile/flu-like illnesses decreased for children 0-4 years and adults 65+ years for week 50, while staying level for those 5-17 years. No specimens were reported as positive for influenza A or B from our 6 sentinel hospital laboratories for week 50. Since Sept. 27, 2020, there have been 8 reports of severe influenza (Philadelphia resident, positive by rapid test, PCR or culture, and hospitalized for ≥ 24 hrs), with no new cases seen in Week 50. Seven cases were influenza A positive and 1 influenza B positive. No cases also tested positive for COVID-19. Zero influenza outbreaks were reported (≥ 1 case of laboratory confirmed flu reported in a long term care facility). Zero influenza-associated deaths have been reported.


Current Report: Click here to download the last weekly report of influenza activity (from Dec. 6, 2020 through Dec. 12, 2020) in a printable format.

Febrile/Flu-like Illnesses at Philadelphia Emergency Departments 2017-2018 Data Compared to 4 Year Historical Weekly Averages
Laboratory-based Surveillance for Influenza A: Philadelphia, 2013/2014 through 2017/2018 Seasons
Laboratory-based Surveillance for Influenza A: Philadelphia, 2013/2014 through 2017/2018 Seasons
Hospitalized Influenza Cases by Age Group
Weekly Counts of Hospitalizations by Flu Type

National and State Influenza Surveillance Updates: 


The Pennsylvania Department of Health (PADOH) reports low activity levels across the state. Since Sept 27,2020 there have been 643 laboratory confirmed cases of influenza (positive by rapid test, PCR, or culture), with 94 new laboratory confirmed cases of influenza seen in Week 50. 16 influenza-associated hospitalizations and 5 deaths have been reported. For more information, please visit:

United States

As of December 12, 2020, the CDC reports that seasonal influenza activity remains lower than usual for this time of year. In clinical laboratories, 75 (0.3%) of 29,578 specimens tested positive for influenza in Week 50 compared to 5,515 (16.3%) of 33,918 specimens testing positive for influenza last year at the same time. There were similar low amounts of positive specimen in public health laboratories. Influenza-like activity seen in outpatient settings is below region specific baselines in all 10 U.S. regions. 1 influenza-associated pediatric death has been reported this season. For more information, please visit: