Influenza-like Illness Surveillance (ILINet)

Description

Information on outpatient visits to health care providers for influenza-like illness (ILI) is collected through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet). ILINet consists of outpatient healthcare providers in all 50 states, Puerto Rico, the District of Columbia and the U.S. Virgin Islands. For this system, ILI is defined as fever (temperature of 100°F [37.8°C] or greater) and a cough and/or a sore throat. The case definition no longer includes “without a known cause other than influenza”. Sites with electronic health records use an equivalent definition as determined by public health authorities. Since ILINet monitors visits for ILI and not laboratory-confirmed influenza, it will capture visits due to any respiratory pathogen that presents with ILI symptoms. The national percentage of patient visits to healthcare providers for ILI reported each week is calculated by combining state-specific data weighted by state population.

Rationale

For Flu tracking and surveilance dashboard

Citation

Centers for Disease Control. U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet). https://wwwn.cdc.gov/ILINet/

Indicators

Name	Indicator Type	Latest Date With Data
Percentage of visits for influenza-like illness (ILI) reported by sentinel providers	Crude Percentage	03/31/2024