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 2022/2023 Influenza Season Data

The Pennsylvania Department of Health monitors influenza activity, conducts laboratory testing and compiles reports on flu activity throughout the year but ramps up surveillance activities in the fall and winter. The official influenza surveillance season starts with the 40th week of the year (typically around the beginning of October) and ends on the 20th week of the following year (in May). For the 2022-2023 season, the influenza surveillance season will begin on Oct. 10, 2022, and will run through May 20, 2023. Updated influenza activity data will be posted on this web page every Wednesday throughout the influenza surveillance season, beginning on October 12. 

These updates will provide a summary on:

  1. When and where influenza activity is occurring;
  2. Current trends in influenza as compared to previous seasons; and
  3. What types and subtypes of influenza viruses are currently circulating. 

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 48 (Ending 12/03/2022)

Pennsylvania Weekly Influenza Report
Summary:

  • Seasonal influenza activity in Pennsylvania and the United States is high and is higher than at the same time of the year during the past eight flu seasons.
  • Influenza A and B are identified by laboratory testing; however, influenza A is the predominant type.
  • Season-to-date, influenza A(H3N2) viruses have been reported by the public health laboratory for most of the specimens that tested positive for flu.
  • A total of 74,832 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 higher than usual for this time of year.
  • Eight confirmed influenza-associated death has 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 12/03/2022 (n= 74,832) - Cases by County and Influenza Type*¥

County
Influenza Type*

TOTAL

ABU**
ADAMS
978
40.1018
ALLEGHENY8183249.8432
ARMSTRONG21315.228
BEAVER633*.634
BEDFORD101*.102
BERKS238492112487
BLAIR12610.136
BRADFORD468*.469
BUCKS259910472710
BUTLER111477*1193
CAMBRIA61786*704
CAMERON45*.46
CARBON395*.396
CENTRE769739815
CHESTER191879.1997
CLARION84*.86
CLEARFIELD3915.396
CLINTON230*.231
COLUMBIA510*.514
CRAWFORD7356.741
CUMBERLAND1104188*1293
DAUPHIN114374*1220
DELAWARE332575.3400
ELK245*.246
ERIE233917.2356
FAYETTE159623.1619
FOREST11..11
FRANKLIN13409.1349
FULTON465.51
GREENE2045.209
HUNTINGDON135..135
INDIANA24151.292
JEFFERSON28417.301
JUNIATA36..36
LACKAWANNA105414.1068
LANCASTER256939*2609
LAWRENCE4567.463
LEBANON5455.550
LEHIGH306438.3102
LUZERNE21725.2177
LYCOMING128*.131
MCKEAN238*.239
MERCER4956.501
MIFFLIN163*.164
MONROE15936.1599
MONTGOMERY4732199384969
MONTOUR74..74
NORTHAMPTON251276.2588
NORTHUMBERLAND4727*480
PERRY7311.84
PHILADELPHIA830580*8387
PIKE169..169
POTTER63*.65
SCHUYLKILL624*.625
SNYDER80*.81
SOMERSET25136.287
SULLIVAN13..13
SUSQUEHANNA248*.249
TIOGA54..54
UNION51..51
VENANGO84*.87
WARREN602..602
WASHINGTON97852*1031
WAYNE29071.361
WESTMORELAND2077109.2186
WYOMING152..152
YORK3664117.3781
All72587213810774832
(*) 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
0
​19-49
​0
​50-64​0
​65+8
​All​8


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