The data shown here are the results obtained by the MDHHS Virology Laboratory from specimens for targeted public health testing plus surveillance testing through the Michigan Sentinel Physician and Sentinel Laboratory Programs. The Sentinel Physician Program consists of medical provider sites from a variety of geographic locations throughout Michigan enrolled in the sentinel surveillance program. These providers represent private practice for adult and pediatric patients, as well as urgent and emergency care facilities, nursing homes and university health services. Michigan is now conducting routine influenza surveillance year-round. Thus, MDHHS requests submission of two to three specimens for influenza A and B viral culture four times during the year: early influenza season, when influenza virus is beginning to circulate; middle season, during the peak of influenza activity; late season, as influenza activity diminishes; and in the summer months. Participation in this program is voluntary.
The complete influenza season runs from October through April. The early/middle/late season definitions vary from year-to-year and are determined on a case-by-case basis.
| Inf B | 2009 A, H1 | Seasonal A, H3 | A, Unsubtypable | LAIV | ||||||||||||||||||||||
| Time | C | N | SE | SW | Tot | C | N | SE | SW | Tot | C | N | SE | SW | Tot | Tot | Tot | |||||||||
| Oct 4 - 10 | 0 | 0 | 1 | 0 | 1 | 5 | 0 | 8 | 6 | 19 | 1 | 0 | 0 | 0 | 1 | 1 | 0 | |||||||||
2026-2027 Guidance Documents
Influenza Test Algorithm - updated 10/2026
Influenza Guidance for Laboratories - updated 10/2026
Influenza Guidance for Healthcare Providers - updated 10/2026
Influenza Guidance for Local Health Departments - updated 10/2026
Antiviral Resistance Information - updated 10/2026
2026-2027 Northern Hemisphere Seasonal Influenza Vaccine Components
The egg-based vaccines contain the following components:
A/Missouri/11/2025 (H1N1)pdm09-like virus
A/Darwin/1454/2025 (H3N2)-like virus
B/Tokyo/EIS13-175/2025 (B/Victoria lineage)-like virus
The recombinant or cell-culture quadrivalent vaccines contain the following components:
A/Missouri/11/2025 (H1N1)pdm09-like virus
A/Darwin/1415/2025 (H3N2)-like virus
B/Pennsylvania/14/2025 (B/Victoria lineage)-like virus
Antiviral Resistance Testing
Antiviral Resistance Information - updated 10/2026
Test Request Form
MDHHS Viral Respiratory Test Request Form - MDHHS-6097 (New 2-24)
Specimen Collection and Shipping
Approved specimen types for influenza testing at the MDHHS BOL:
- Upper respiratory tract specimens such as nasopharyngeal swabs (NP), nasal swabs (NS), throat swabs (TS), dual NP/TS swabs, nasal washes (NW), and nasal aspirates (NA)
- Lower respiratory tract specimens such as bronchoalveolar lavage (BAL), bronchial washes (BW), tracheal aspirates (TA), sputum (PCR only), lung tissue, and viral culture
Quick Guide for Packaging and Shipping Influenza Specimens to BOL - updated 11/15/2010
MDHHS BOL Flu Collection and Submission Guide - DCH-0772 (Rev 02/2024)
Biological Substance, Category B Shipping Label - DCH-0800 (Rev. 1-16)
CDC Influenza Advisories
Influenza Resources
National influenza surveillance summary information:
CDC Weekly Influenza Surveillance page
The CDC Influenza page
The World Health Organization
Archived Influenza Season Data
Rev 10/19/2026