Do family physicians make good sentinels for influenza?

Area of Science:

• Epidemiology
• Public Health Surveillance
• Infectious Disease Monitoring

Background:

• Influenza surveillance relies on multiple systems, including those from the Centers for Disease Control and Prevention.
• The utility of volunteer family physician reports in augmenting existing influenza surveillance data requires evaluation.

Purpose of the Study:

• To assess the value of volunteer family physician reports in supplementing influenza-like illness (ILI) data from other surveillance systems.
• To determine if physician reports provide timely and accurate information on influenza activity.

Main Methods:

• Evaluation of family physician reports over five influenza seasons (1987-1992) across the United States.
• Data collection involved an average of 140 physicians per season, documenting office visits and hospitalizations for ILI.
• ILI was defined by fever and cough, sore throat, or myalgia, with physician's clinical judgment of influenza; some physicians collected specimens for viral confirmation.

Main Results:

• Physicians reported 5% of over 1.6 million office visits as ILI, with 3% of ILI patients hospitalized.
• Individuals aged 65 and older represented 11% of ILI visits and 43% of ILI hospitalizations.
• Physician-reported influenza isolates peaked 1-4 weeks earlier than World Health Organization laboratory data and peak morbidity was reported earlier than state health departments.

Conclusions:

• Volunteer family physicians offer sensitive, timely, and accurate community influenza morbidity data.
• Physician-reported data effectively complements existing surveillance systems for monitoring influenza.
• This enhanced surveillance aids in understanding influenza type, timing, and intensity, supporting public health interventions.