Strep throat is a bacterial infection caused by Streptococcus pyogenes (group A Streptococcus or GAS). It primarily affects the throat and tonsils, leading to inflammation and discomfort. This common infection is particularly prevalent among children and adolescents.
How Strep Throat Spreads
Strep throat primarily spreads through respiratory droplets expelled when an infected individual coughs, sneezes, or talks. These droplets can travel a short distance through the air and be inhaled by nearby individuals. Transmission often requires close contact with an infected person.
Beyond inhaling droplets, direct contact with respiratory secretions also spreads the bacteria. This occurs if someone touches contaminated surfaces, such as doorknobs or toys, and then touches their own eyes, nose, or mouth.
Sharing personal items like eating utensils, cups, or food is another common mode of transmission. The bacteria can live in traces of an infected person’s saliva or nasal discharge.
Preventing the Spread
Preventing the spread of strep throat involves several practical steps. Frequent and thorough handwashing with soap and water for at least 20 seconds is effective. It is especially important to wash hands before eating and after coughing or sneezing.
Individuals should cover coughs and sneezes with a tissue or, if a tissue is unavailable, into their elbow to contain respiratory droplets. Avoiding the sharing of eating utensils, cups, and food is important.
Cleaning and disinfecting frequently touched surfaces like doorknobs, light switches, and toys can reduce the presence of bacteria. Staying home from work, school, or other activities when sick prevents transmission to others. If soap and water are not available, an alcohol-based hand sanitizer with at least 60% alcohol can be used.
When is Strep Throat Contagious?
An individual with strep throat is contagious during the incubation period, which can last two to five days after exposure. Contagiousness is highest when symptoms are most severe. Some individuals may carry and spread the bacteria without showing symptoms, though they are generally less contagious.
With antibiotic treatment, contagiousness decreases. An infected person stops being contagious within 24 to 48 hours after starting antibiotics. Individuals can return to school or work once this period has passed and their fever has subsided.
Without antibiotic treatment, individuals can remain contagious for an extended period, increasing the risk of spreading the infection and developing complications. Complete the full course of prescribed antibiotics, even if symptoms improve, to ensure the infection is fully resolved and to minimize ongoing contagiousness.