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Government, businesses and other employers need guidance about when workers who have been ill with influenza should return to the workplace. This document provides an overview of influenza symptoms, criteria for employee return, and important qualifications for use of this information during a pandemic flu.

Overview of influenza virus symptoms

Influenza viruses are spread from person to person primarily through respiratory droplet transmission (e.g., when an infected person coughs or sneezes in close proximity, normally 3 feet or less, to an uninfected person). The virus may also be spread through contact with infectious respiratory secretions on the hands of an infected person or by touching objects or surfaces contaminated with the virus. The typical incubation period for seasonal influenza is 1 - 4 days, with an average of 2 days. Adults can be infectious from the day before symptoms begin through approximately 5 - 7 days after illness onset. Children can be infectious for >10 days after the onset of symptoms. Severely immunocompromised persons can be infectious for weeks or months.

Current criteria for returning to work

Workers who have become ill with influenza should stay at home until all of the following criteria are met:

  • At least 5 days have passed since the symptoms of illness began; AND
  • Fever has resolved and has not been present for at least 24 hours; AND
  • Cough is improving (decreasing in frequency and amount of secretions with no associated chest discomfort or shortness of breath)

Upon returning to the work environment, employees should continue to follow cough etiquette and hand washing protocols.

Criteria for pandemic influenza

Experts do not know whether the mode of transmission, incubation period, or contagious period of pandemic strains of the influenza virus will be similar to those of seasonal influenza (recurring yearly), Because of this, employers must be vigilant for specific recommendations from Public Health during an influenza pandemic regarding management of illness in the workplace, including when it is safe for workers to return to the work environment after illness with influenza.