Weekly Influenza & Respiratory Activity: Statistics

Weekly Influenza and Respiratory Illness Activity Reports:

• Influenza Respiratory Illness Activity Report - Week 43 (PDF)
  Week Ending October 26, 2024 | WEEK 43
• Influenza Respiratory Illness Activity Report - Week 42 (PDF)
  Week Ending October 19, 2024 | WEEK 42
• Influenza Respiratory Illness Activity Report - Week 41 (PDF)
  Week Ending October 12, 2024 | WEEK 41
• Influenza Respiratory Illness Activity Report - Week 40 (PDF)
  Week Ending October 5, 2024 | WEEK 40
• Off-Season Influenza Respiratory Illness Activity Report - Week 39 (PDF)
  Week Ending September 28, 2024 | WEEK 39
• Off-Season Influenza Respiratory Illness Activity Report - Week 38 (PDF)
  Week Ending September 21, 2024 | WEEK 38
• Off-Season Influenza Respiratory Illness Activity Report - Week 37 (PDF)
  Week Ending September 14, 2024 | WEEK 37
• Off-Season Influenza Respiratory Illness Activity Report - Week 36 (PDF)
  Week Ending September 7, 2024 | WEEK 36
• Off-Season Influenza Respiratory Illness Activity Report - Week 35 (PDF)
  Week Ending August 31, 2024 | WEEK 35
• Off-Season Influenza Respiratory Illness Activity Report - Week 34 (PDF)
  Week Ending August 24, 2024 | WEEK 34
• Off-Season Influenza Respiratory Illness Activity Report - Week 33 (PDF)
  Week Ending August 17, 2024 | WEEK 33
• Off-Season Influenza Respiratory Illness Activity Report - Week 32 (PDF)
  Week Ending August 10, 2024 | WEEK 32
• Off-Season Influenza Respiratory Illness Activity Report - Week 31 (PDF)
  Week Ending August 3, 2024 | WEEK 31
• Off-Season Influenza Respiratory Illness Activity Report - Week 30 (PDF)
  Week Ending July 27, 2024 | WEEK 30
• Off-Season Influenza Respiratory Illness Activity Report - Week 29 (PDF)
  Week Ending July 20, 2024 | WEEK 29
• Off-Season Influenza Respiratory Illness Activity Report - Week 28 (PDF)
  Week Ending July 13, 2024 | WEEK 28
• Off-Season Influenza Respiratory Illness Activity Report - Week 27 (PDF)
  Week Ending July 6, 2024 | WEEK 27
• Influenza Respiratory Illness Activity Report - Week 20 (PDF)
  Week Ending May 18, 2024 | WEEK 20
• Influenza Respiratory Illness Activity Report - Week 19 (PDF)
  Week Ending May 11, 2024 | WEEK 19
• Influenza Respiratory Illness Activity Report - Week 18 (PDF)
  Week Ending May 4, 2024 | WEEK 18
• Influenza Respiratory Illness Activity Report - Week 17 (PDF)
  Week Ending April 27, 2024 | WEEK 17
• Influenza Respiratory Illness Activity Report - Week 16 (PDF)
  Week Ending April 20, 2024 | WEEK 16
• Influenza Respiratory Illness Activity Report - Week 15 (PDF)
  Week Ending April 13, 2024 | WEEK 15
• Influenza Respiratory Illness Activity Report - Week 14 (PDF)
  Week Ending April 6, 2024 | WEEK 14
• Influenza Respiratory Illness Activity Report - Week 13 (PDF)
  Week Ending March 30, 2024 | WEEK 13
• Influenza Respiratory Illness Activity Report - Week 12 (PDF)
  Week Ending March 23, 2024 | WEEK 12
• Influenza Respiratory Illness Activity Report - Week 11 (PDF)
  Week Ending March 16, 2024 | WEEK 11
• Influenza Respiratory Illness Activity Report - Week 10 (PDF)
  Week Ending March 9, 2024 | WEEK 10
• Influenza Respiratory Illness Activity Report - Week 9 (PDF)
  Week Ending March 2, 2024 | WEEK 9
• Influenza Respiratory Illness Activity Report - Week 8 (PDF)
  Week Ending February 24, 2024 | WEEK 8
• Influenza Respiratory Illness Activity Report - Week 7 (PDF)
  Week Ending February 17, 2024 | WEEK 7
• Influenza Respiratory Illness Activity Report - Week 6 (PDF)
  Week Ending Feb. 10, 2024 | WEEK 6
• Influenza Respiratory Illness Activity Report - Week 5 (PDF)
  Week Ending Feb. 3, 2024 | WEEK 5
• Influenza Respiratory Illness Activity Report - Week 4 (PDF)
  Week Ending Jan. 27, 2024 | WEEK 4
• Influenza Respiratory Illness Activity Report - Week 3 (PDF)
  Week Ending Jan. 20, 2024 | WEEK 3
• Influenza Respiratory Illness Activity Report - Week 2 (PDF)
  Week Ending January 13, 2024 | WEEK 2
• Influenza Respiratory Illness Activity Report - Week 1 (PDF)
  Week Ending January 6, 2024 | WEEK 1
• Influenza Respiratory Illness Activity Report - Week 52 (PDF)
  Week Ending December 30, 2023 | WEEK 52
• Influenza Respiratory Illness Activity Report - Week 51 (PDF)
  Week Ending December 23, 2023 | WEEK 51
• Influenza Respiratory Illness Activity Report - Week 50 (PDF)
  Week Ending December 16, 2023 | WEEK 50
• Influenza Respiratory Illness Activity Report - Week 49 (PDF)
  Week Ending December 9, 2023 | WEEK 49
• Influenza Respiratory Illness Activity Report - Week 48 (PDF)
  Week Ending December 2, 2023 | WEEK 48
• Influenza Respiratory Illness Activity Report - Week 47 (PDF)
  Week Ending November 25, 2023 | WEEK 47
• Influenza Respiratory Illness Activity Report - Week 46 (PDF)
  Week Ending November 18, 2023 | WEEK 46
• Influenza Respiratory Illness Activity Report - Week 45 (PDF)
  Week Ending November 11, 2023 | WEEK 45
• Influenza Respiratory Illness Activity Report - Week 44 (PDF)
  Week Ending November 4, 2023 | WEEK 44

Unlike other reportable diseases, MDH does not request that every case of influenza or every patient who goes to the doctor with influenza symptoms be reported to MDH. Tracking each case would overburden health care providers as well as MDH, without significant benefit. Instead, MDH uses several different surveillance programs to determine the burden of influenza disease in Minnesota each week (influenza-like illness [ILI] outbreaks at schools and long-term care facilities, outpatient/clinic visits for ILI, laboratory-confirmed influenza in hospitalized patients, and laboratory testing for influenza and other respiratory disease).

Keeping Track of Flu in Minnesota

Many people get sick with flu every year in Minnesota without ever seeing a doctor or reporting their illness. Therefore, MDH uses various indicators to find out how widespread the flu is in Minnesota each week, rather than trying to track every case. The MDH Public Health Laboratory (PHL) also tests selected influenza specimens to monitor which flu strains are circulating each flu season.

Hospitalized Surveillance

Hospitals report to MDH when they have a patient admitted to the hospital with laboratory-confirmed influenza. Hospitals are asked to submit specimens to MDH-PHL for influenza testing. MDH provides guidance on infection control and outbreak management, including the use of antiviral medication for treatment and prevention.

Sentinel Surveillance

Physicians and health care providers across the state help to monitor influenza throughout the flu season. Sentinel providers fill out a weekly report detailing the number of patients they've seen with influenza-like illness. They also submit additional influenza specimens to the MDH Public Health Lab according to the Sentinel Surveillance program guidelines.

Long-Term Care Facility Surveillance

Facilities report to MDH when they have a suspected or laboratory confirmed influenza outbreak. Specimens can be submitted to MDH-PHL for influenza testing. MDH provides guidance on infection control and outbreak management, including the use of antiviral medication for treatment and prevention.

School Surveillance

Minnesota K-12 schools report outbreaks of acute respiratory illness (ARI) to MDH when the number of students absent with ARI reaches 10 percent of total school enrollment. These reports, although not based on laboratory confirmation, help determine the impact of influenza and other respiratory viruses on school age children in concordance with other surveillance activities.

MLS Laboratory Surveillance

The MN Lab System (MLS) Laboratory Influenza Surveillance Program is made up of more than 100 clinic- and hospital-based laboratories, voluntarily submitting testing data on a weekly basis. These laboratories perform rapid testing for Influenza and Respiratory Syncytial Virus (RSV). Significantly fewer labs, a total of seven, perform confirmatory culture testing for Influenza and RSV. Tracking the laboratory results assists health care providers with patient diagnosis of influenza-like illness and provides an indicator as to the progression of the influenza season as well as prevalence of disease in the community. If your laboratory is interested in participating in this program, please call 651-201-5581.

MLS Virology Laboratory Isolate Surveillance

Viral isolates are subtyped to monitor for the introduction of new influenza virus strains and compared to the current vaccine subtypes. MDH-PHL performs hemagglutinin subtyping on isolates submitted from virology laboratories serving MN patients. Selected influenza isolates are forwarded to CDC for neuraminidase subtyping.