Strep Throat: Causes

What causes strep throat?

Strep throat is caused by an infection of the throat and tonsils by group A Streptococcus bacteria. Despite popular belief, strep throat, colds, and other types of upper respiratory infections are not caused by being wet or cold, although in some cases these conditions may lower the body’s resistance to bacterial and other types of infections.  

Strep throat is contagious and spreads quickly from person to person when someone with strep throat talks, coughs or sneezes. This shoots droplets contaminated with group A Streptococcus bacteria into the air, where others can breathe them in.

Strep throat also spreads when a person touches a person who has strep throat or a surface contaminated by group A Streptococcus bacteria, such as a contaminated computer keyboard or doorknob. Touching the mouth, eyes or nose before washing your hands can transmit the bacteria from the hands into the body.

What are the risk factors for catching strep throat?

Strep throat can occur in any age group or population. A number of factors increase the risk of catching strep throat, although not all people with risk factors will catch strep throat. Risk factors for catching strep throat include:

• Close exposure to a person with strep throat

• Poor hygiene habits, such as not washing your hands after contact with a person who has strep throat or after touching surfaces that are often contaminated with strep throat bacteria, such as doorknobs, computer keyboards, and telephones. Sharing unwashed drinking glasses, spoons, forks, and personal items, such as lip balm and toothbrushes, can also spread bacteria.

• Young age, such as preschool and elementary school children

Reducing your risk of strep throat

You can lower your risk of catching or spreading strep throat by:

• Avoiding contact with a person who has strep throat

• Avoiding touching the eyes, nose and mouth, which can transmit strep throat bacteria from the hands into the body

• Covering the mouth and nose with the elbow (not the hand) or a tissue when sneezing or coughing

• Not sharing unwashed drinking glasses, dishware, or personal items, such as lip balm and toothbrushes

• Using appropriate antibacterial cleaners to clean hands and surfaces

• Washing hands frequently during and after contact with a person who has strep throat

• Washing hands frequently throughout the day with soap and water for at least 15 seconds