Begin Main Content Area

 2022/2023 Influenza Season Data

Note: PA DOH continuously conducts flu surveillance throughout the year. Currently, flu activity is at interseasonal levels, which is relatively low. As a result, the flu activity report will be paused until the next flu season when flu activity is expected to increase.

It is important to note that the influenza case counts presented on this page are restricted to only those cases that have had a positive laboratory test for flu (by rapid test, DFA, PCR or culture) reported to the PADOH. These case counts represent only a fraction of the actual burden of illness due to influenza occurring in the commonwealth at any given time. This is because most persons with influenza do not go to the doctor or are not tested or reported. Influenza spread and severity varies widely from season to season. It is estimated that five to 20 percent (600,000 to 2,400,000) of Pennsylvanians get the flu each year, and 120 to 2,000 die from complications of influenza.

Week 17 (Ending 4/29/2023)

Pennsylvania Weekly Influenza Report Summary:

    • Seasonal influenza activity in Pennsylvania and the United States is low.
    • Influenza A and B are identified by laboratory testing. While the most frequently reported and subtyped influenza virus this season is A(H3N2), the predominant type in the past few weeks has been Influenza B.
    • A total of 186,611 laboratory-confirmed influenza cases have been reported season to date. Confirmed reports were received from the 67 state counties.
    • The percent of emergency department visits associated with influenza-like illness is low at this time.
    • A total of 169 confirmed influenza-associated deaths have been reported during the current season.

Confirmed Influenza Laboratory Tests Received by PA DOH Surveillance

Table 1. Influenza Cases (positive by rapid test, PCR, or culture) Reported in Pennsylvania, 10/02/2022 to 4/29/2023 (n=186,611) - Cases by County and Influenza Type*¥

County Influenza Type*
TOTAL
ABU**
ADAMS3020199.3219
ALLEGHENY14975876.15851
ARMSTRONG89938.937
BEAVER20139*2023
BEDFORD4879*498
BERKS4906412185336
BLAIR85833.891
BRADFORD16426.1648
BUCKS5605403136021
BUTLER2792207*3001
CAMBRIA241330772727
CAMERON62*.65
CARBON133710.1347
CENTRE237844412463
CHESTER4126256*4384
CLARION45315.468
CLEARFIELD163711.1648
CLINTON6507.657
COLUMBIA134912.1361
CRAWFORD183221.1853
CUMBERLAND35016111514263
DAUPHIN4001424*4428
DELAWARE6013297*6311
ELK5089.517
ERIE46343154670
FAYETTE246447*2512
FOREST30*.31
FRANKLIN3402120.3522
FULTON20921.230
GREENE36610.376
HUNTINGDON5606.566
INDIANA966161.1127
JEFFERSON78047*828
JUNIATA271*.274
LACKAWANNA360174.3675
LANCASTER9632219*9852
LAWRENCE94429.973
LEBANON251174.2585
LEHIGH7231166.7397
LUZERNE663082*6713
LYCOMING122517.1242
MCKEAN488*.490
MERCER128025.1305
MIFFLIN958*.961
MONROE365556*3712
MONTGOMERY8926788649778
MONTOUR466*.468
NORTHAMPTON6091245*6340
NORTHUMBERLAND192624*1952
PERRY36755.422
PHILADELPHIA15871404*16277
PIKE539*.543
POTTER21216*229
SCHUYLKILL236516.2381
SNYDER398*.399
SOMERSET59376.669
SULLIVAN77..77
SUSQUEHANNA7585.763
TIOGA381*.382
UNION359*.360
VENANGO48310.493
WARREN704..704
WASHINGTON1665152*1819
WAYNE1263350.1613
WESTMORELAND4306366.4672
WYOMING52910.539
YORK10165607*10773
All1777388546327186611

(*) Numbers smaller than 5 have been replaced with an asterisk

(¥) Influenza counts are provisional and may change as more information is received

(**) Test results may identify influenza Type A, influenza Type B, or influenza without specifying Type A or B. Some tests only give a positive or negative result and can-not identify influenza type.

Figure 1. Number of Pa. Influenza Cases by Week of First Report

Figure 1. Number of Pa. Influenza Cases by Week of First Report


Figure 2: Comparison of PA-NEDSS Influenza Cases (All Types) in Current Season to the Eight Previous Seasons

Figure 2: Comparison of PA-NEDSS Influenza Cases (All Types) in Current Season to the Eight Previous Seasons

Figure 3: Season-to-date Influenza Sub-Typing Results From State Public Health Lab

Figure 3: Season-to-date Influenza Sub-Typing Results From State Public Health Lab

Table 2: Season-To-Date Influenza-Associated Deaths by Age

​Age ​Influenza-Associated Death
​0-18
2
​19-49
9
​50-64
26
​65+132
​All
169


Syndromic Surveillance

The Pennsylvania Department of Health's syndromic surveillance system receives data on visits to emergency departments (EDs) from most hospitals in the state.  The system looks at the reason for visiting the ED and determines if ED visits were likely due to influenza-like illness (ILI). The graph displays ED visits due to ILI as a percentage of total ED visits. This provides yet another way for the Department of Health to monitor influenza and ILI in the state. 

Figure 4: season-to-date Influenza-Like Illness (ILI) Emergency Visits

Figure 4: season-to-date Influenza-Like Illness (ILI) Emergency Visits

Figure 5: season-to-date Influenza-Like Illness (ILI) Emergency Visits by community health districts 

Figure 5: season-to-date Influenza-Like Illness (ILI) Emergency Visits by community health districts

Figure 6: season-to-date Influenza-Like Illness (ILI) Emergency Visits by age groups

Figure 6: season-to-date Influenza-Like Illness (ILI) Emergency Visits by age groups

World Health Organization (WHO) and National Respiratory & Enteric Virus Surveillance System (NREVSS) Collaborating Laboratories

Thirteen clinical virology laboratories in Pa. are WHO and/or NREVSS collaborating laboratories for influenza surveillance.

These labs report weekly the number of respiratory specimens tested and the number positive for influenza types A and B to CDC. Some labs also report the influenza A subtype (H1 or H3) and influenza B lineage (Victoria or Yamagata). Because denominator data is provided, the weekly percentage of specimens testing positive for influenza is calculated.

Figure 7: Influenza Test Results Reported to the National Respiratory and Enteric Virus Surveillance System (NREVSS) Select Pennsylvania Laboratories, Season to date

Figure 7: Influenza Test Results Reported to the National Respiratory and Enteric Virus Surveillance System (NREVSS) Select Penn