Seasonal Influenza in Philadelphia
Philadelphia Seasonal Influenza Activity:     
Number of Lab-Confirmed Reports: 11*
Number of Hospitalized Cases: 11**
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 (03/22/2021)

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 10: Febrile/flu-like illnesses continued to remain lower than normal for week 10 among all age groups. No specimen was reported as positive for influenza A or B from our 6 sentinel hospital laboratories for week 10. Since Sept. 27, 2020, there have been 11 reports of severe influenza (Philadelphia resident, positive by rapid test, PCR or culture, and hospitalized for ≥ 24 hrs). Zero influenza outbreaks were reported (≥ 1 case of laboratory confirmed flu reported in a long term care facility). Zero influenza-associated deaths confirmed by PCR have been reported.


Current Report: Click here to download the last weekly report of influenza activity (from Mar. 7, 2021 through Mar. 13, 2021) 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) continues to report low activity levels across the state. Since Sept. 27, 2020, there have been 2,991 laboratory confirmed cases of influenza (positive by rapid test, PCR, or culture). 38 influenza-associated hospitalizations have been reported across PA, with an increase of 1 hospitalization in the past week. 15 deaths have been reported this flu season. For more information, please visit:

United States

As of March 13, 2021, the CDC reports that seasonal influenza activity remains lower than usual for this time of year. In clinical laboratories, 27 (0.1%) of 23,618 specimens tested positive for influenza in Week 10, with similar low reports of influenza positives reported in public health laboratories. All jurisdictions reported minimal level of flu activity. The current cumulative hospitalization rate is 0.7 per 100,000, which is about 1/4 the rate at this time during the low severity 2011-2012 year. For more information, please visit: