Seasonal Influenza in Philadelphia
Philadelphia Seasonal Influenza Activity:     
Number of Lab-Confirmed Reports: 4,779*
Number of Hospitalized Cases: 889**
Number of Deaths: 17
*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 (03/02/2020)

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 WIDESPREAD 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 08: Febrile/flu-like illnesses decreased among all age groups during week 7. 451 specimens were reported from our sentinel hospital laboratory surveillance for influenza A and B during the same time period among the 6 participating laboratories, a majority of which (329) was influenza A. 50 reports of severe influenza (Philadelphia resident, positive by rapid test, PCR or culture, and hospitalized for ≥ 24 hrs) have been reported this week (season-to-date = 889), with 45 reports (90%) positive for influenza A. 3 influenza outbreaks (≥ 1 case of laboratory confirmed influenza reported in a long term care facility) were reported. 17 influenza-associated deaths have been reported with no pediatric mortalities to date.


Current Report: Click here to download the last weekly report of influenza activity (from Feb. 16, 2020 through Feb. 22, 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 continues to report widespread activity, with a decrease in positive laboratory tests from over 10,000 cases reported last week to above 7,000 cases reported this week. Of Influenza A, A/pH1N1 is the most prominent strain, as 82% of the 225 sub-typing results from the state public health lab was positive for A/pH1N1. 2,228 flu-associated hospitalizations and 66 flu-associated deaths have been reported. For more information, please visit:

United States

Flu activity has decreased for the second week in a row, with percentage of specimen testing positive for influenza B reducing while the percentage testing positive for influenza A continuing to increase. Interim estimates of flu vaccine effectiveness (VE) for preventing medically attended, laboratory-confirmed flu virus infection shows VE was 45% against influenza A and B virus types combined, 50% against influenza B/Victoria, and 37% against A(H1N1)pdm09.125 influenza-associated deaths in children have been reported this season. For more information, please visit: