Influenza Sentinel Surveillance

The Influenza Sentinel Surveillance Program is one of the surveillance activities used by VDH to track influenza (flu) in Virginia.

The flu season typically begins around MMWR week 40 (early October) with activity decreasing by MMWR week 20 (mid to late May). Each flu season, VDH partners with select outpatient, urgent care, long-term care facilities, federally qualified health centers, student health, pediatric facilities and emergency department providers to collect specimens from individuals with an influenza-like illness (ILI) symptom to test for influenza and further characterize the type and subtype of any positive influenza results. This surveillance effort allows VDH to determine which virus strains are circulating in Virginia, monitor for any novel strains within the community, and provide data for future vaccine formulation decisions.

The goal of the SS program is to receive at least 175 specimens per week across the state during the flu season.


ILI Case Definition

FEVER of 100ºF or more with


Important links for sentinel providers

Sentinel Surveillance – Fact Sheet (Updated 8/23)

Influenza Sentinel Surveillance Brochure (Updated 8/23)

Sentinel Flu Provider Instructions (Updated as of 8/23)

SAF-T-PAK Packing Instructions (Updated as of 8/23)

DCLS Test Request Form {Flu Sentinel ONLY} (Updated as of 8/23)

Current Virginia Activity Level Report

CDC FluView Activity Report

Please direct any questions on the influenza surveillance program to or contact your local health department at