Seasonal Influenza in Philadelphia
Philadelphia Seasonal Influenza Activity:     
Number of Lab-Confirmed Reports: 1,290*
Number of Hospitalized Cases: 215**
Number of Deaths: 3
*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 (01/14/2020)

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 01: Febrile/flu-like illnesses increased among children ages 0-4 years and adults (18 years and older). Four-hundred and ninety-six positive 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 (353) was influenza B. 29 reports of severe influenza (Philadelphia resident, positive by rapid test, PCR or culture, and hospitalized for ≥ 24 hrs) have been reported this week, with 19 positive for influenza A. 2 influenza outbreaks (≥ 1 case of laboratory confirmed influenza reported in a long term care facility) were reported this week. 3 influenza-associated deaths have been reported season-to-date.  

Current Report: Click here to download the last weekly report of influenza activity (from Dec. 29, 2019 through Jan. 4, 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 reports widespread activity. Reports of lab-confirmed cases decreased from Week 52 of 2019 (n=6,800) to Week 1 of 2020 (n=5,800). Of the 25, 362 season-to-date, lab-confirmed cases of influenza (positive by rapid test, PCR, or culture), 18, 488 (72.9%) have been identified as influenza B. 477 flu-associated hospitalizations and 13 influenza-associated deaths have been reported. For more information, please visit:

United States

46 states are reporting widespread influenza activity, with 36 states experiencing high ILI activity. The percentage of respiratory specimen that tested positive for influenza at clinical labs decreased from 26.4% to 23.3% this week. The majority of specimens tested in clinical laboratories were positive for influenza B (7,257, 63.3%). CDC has antigenically characterized 50 B/Victoria and 66 A(H1N1) influenza viruses and has found that 29 (58%) of B/Victoria and 66 (100%) of A(H1N1) viruses were antigenically similar to the cell-grown reference viruses in the current vaccine. Almost all (>99%) tested viruses show susceptibility antiviral medications. For more information, please visit: