Washington State University
Environmental Health & Safety EH&S Factsheets

Respiratory Protection:

Its Role in Seasonal Influenza


What is Seasonal Influenza?

Seasonal influenza, commonly called “the flu,” is a contagious respiratory illness caused by a virus infecting the respiratory tract (nose, throat, lungs). In most people, the flu is uncomfortable, tiring, and can keep you bedridden for many days. In seniors, young children, and people with chronic (long-term) lung diseases like asthma and COPD, the flu can be more serious.

How is Seasonal Flu Transmitted?

Seasonal flu is transmitted from person-to-person primarily via virus-laden large droplets generated when infected persons cough or sneeze; these large droplets can then be directly deposited onto the mucus membranes of the upper respiratory tract (nose, mouth) of susceptible persons. Transmission may also occur through direct and indirect body contact with infectious respiratory secretions, such as touching a contaminated surface and then touching the mouth, nose or eyes.

Other Steps to Prevent the Flu

  • Avoid close contact with people who are sick. Wash your hands thoroughly and frequently, especially after using the rest room and before eating or touching your face.
  • Avoid touching your eyes, nose or mouth. Germs are often spread when a person touches something that is contaminated with germs and then touches his or her eyes, nose, or mouth.
  • Surfaces commonly contacted by hands should also be disinfected periodically. These include, but are not limited to: telephones, computer keyboards and mice, door knobs, drinking fountains, sink faucet handles, paper towel dispensers, and tables and desk tops.

Can I Catch the Flu through a Building Ventilation System?

The flu virus does not stay suspended in the air; therefore, it does not travel through ventilation systems.

Getting Assistance

Consult WSU Health and Wellness Programs or your health care provider regarding your annual flu vaccine. Additional information is also available from the CDC. If you have questions about respiratory protection, please contact EH&S.

How Can I Protect Myself?

There are a number of steps one can take to protect themselves from the flu. By far, the single best way to prevent the flu is for individuals to get a vaccination each fall. Consult with your health care provider or the local county health officer for additional information.

Should I Wear a Mask?

According to the Centers for Disease Control and Prevention (CDC), surgical or procedure masks are not usually recommended in non-healthcare settings. Adults can shed the flu virus one day before symptoms appear and up to seven days after onset of illness; thus, the use of masks may not effectively limit transmission. Instead emphasis should be placed on cough etiquette:

  • Cover your nose and mouth with a tissue or use the upper part of your sleeve, not your hands, when coughing or sneezing
  • Use tissues to contain respiratory secretions and, after use, dispose of them in the nearest waste receptacle
  • Wash you hands often with soap and water, especially if they become contaminated with respiratory secretions.

Persons with the flu should remain at home until the fever and coughing are resolved to avoid exposing the public. If you are ill and cannot stay home, then consider wearing a mask in public places when you have close contact with other persons. Additionally, if you are in close contact with individuals who are coughing and sneezing, then you might want to consider wearing a mask.

Although the virus particles are very small, they do not travel by themselves through the air. They need to be transported on droplets from sneezes and coughs, and these masks serve as a barrier.

A disposable filtering respirator (e.g., N95) does not afford any greater level of protection than a mask and are not recommended. However, if you elect to wear such a respirator, you should consult your health care provider since respirators can increase the demand on the cardiovascular system.