Strep throat is contagious for about 2-3 weeks in individuals who do not take antibiotics. However, individuals who take antibiotics for strep throat usually are no longer contagious about 24 hours after initiating antibiotic therapy. The bacteria that cause strep throat can be transmitted person-to-person by direct contact, especially from mucus droplets from the mouth, and by indirect contacts, such as kissing and sharing utensils or drinking cups.
What is strep throat?
If strep throat is treated with antibiotics, it is no longer contagious after 24 hours.
- Strep throat is a contagious throat infection usually caused by group A streptococcal bacteria.
- The incubation period for strep throat is between 1-5 days after being exposed to the bacteria.
- Strep throat is often accompanied by symptoms and signs, for example:
- Strep throat is one of many causes of inflammation of the pharynx (pharyngitis), also referred to an as sore throat.
- Streptococcus spp. is the most common bacterial species to cause a sore throat (15%-30% of pharyngitis in children and about 5 to 10% in adults).
- A rapid strep test can be done in your doctor's office to determine if you have strep or a sore throat.
- Usually, people with strep throat are treated with antibiotics and aren't contagious for about 24 hours after starting the antibiotics. However, strep throat that is not treated with antibiotics is contagious for about 2-3 weeks after exposure.
- There are many other causes of the sore throat including many viruses, bacteria other than strep, allergies, acid reflux, and tumors. Your doctor can help sort through the causes of your sore throat.
Strep Throat Symptoms
Signs of infection
Streptococcus infection (strep throat) symptoms are related to the inflammation of the throat and surrounding tissues.
Common symptoms of strep throat are
- mild to severe sore throat,
- redness and swelling of the throat,
- white spots or patches on the tonsils, and ...
What are the signs and symptoms of strep throat?
The incubation period for strep throat varies about 1-5 days after exposure to the bacteria. If you develop a sore throat and a fever, you should consider the possibility that you may have strep throat, especially if another family member or a coworker has been diagnosed with the disease. The pattern of symptoms of strep throat include:
- Sore throat
- Fever (usually greater than 102 F or 38.8 C)
- Whitish or yellowish pus areas on the tonsils and throat
Some people with strep throat also may develop:
- Muscle pain
- Nausea and vomiting
- Strep throat is often accompanied by swollen lymph nodes in the neck.
- Rarely, a person with strep throat can develop a rash.
- If you have a runny nose, constant sneezing, and coughing, it is less likely that you have strep throat.
Sore Throat or Strep Throat? How to Tell the Difference
How is strep throat spread?
- Strep throat is easily spread by exposure to droplets from an infected person's sneeze or cough.
- Kissing can also cause person-to-person spread.
- Moreover, streptococci can survive for a while on toothbrushes, doorknobs, and other objects. If people who do not have strep throat touch these contaminated objects, and subsequently touch their mouth or nose, they can become infected.
Is there a test to diagnose strep?
Strep throat is diagnosed by the medical history, physical examination of the throat, and a rapid strep test on a swab of the throat. The rapid strep test can be confirmed by a throat culture. However, most physicians will diagnose and begin treatment before a throat culture test is completed. You will receive the results of the test the same day.
How do I know when I'm cured of the infection?
- Individuals can be cured of strep throat by taking antibiotics.
- A person taking antibiotics is no longer contagious after about 24 hours.
- Without taking antibiotics, persons with strep throat are infectious for about three weeks.
- A person is cured when symptoms are cleared.
Is strep throat serious? When should I call the doctor?
If you suspect that you have strep throat, you should contact a doctor; however, it is more urgent if you have these symptoms and signs.
- Have a fever over 102 F or 38.8 C
- Are dehydrated and have an associated headache, abdominal pain, and/or nausea and vomiting.
- Develop symptoms of drooling, difficulty breathing, and/or swallowing
The major reason to seek medical care for strep throat is that if it goes untreated or is not appropriately treated, serious complications can develop, and include:
Early treatment of strep throat can help prevent these and other complications.
Is Strep Throat Contagious?
See a picture of strep throat and other oral health conditions
Medically Reviewed on 5/13/2022
Khan, ZZ. et al. "Group A Streptococcal Infections." Medscape. Updated: Sep 07, 2018.