Is Strep Throat Contagious? 12 Symptoms and Signs

  • Medical Author:
    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

  • Medical Editor: William C. Shiel Jr., MD, FACP, FACR
    William C. Shiel Jr., MD, FACP, FACR

    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

What is strep throat?

  • 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 as sore throat.
  • Streptococcus spp. are 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 youi 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 antbiotics. However, strep throat that is not treated with antibiotics is contagious for about 2-3 weeks after exposure.
  • There are many other causes of 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.

Is strep throat contagious?

Strep throat is contagious for about 2-3 weeks in individuals that do not take antibiotics. However, individuals that 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 indirect contact, such as kissing and sharing utensils or drinking cups.

Strep Throat Symptoms

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:

  1. Ssore throat
  2. Fever (usually greater than 102 F or 38.8 C)
  3. Whitish or yellowish pus areas on the tonsils and throat

Some people with strep throat also may develop:

  1. Headache
  2. Muscle pain
  3. Nausea and vomiting
  4. Strep throat is often accompanied by swollen lymph nodes in the neck.
  5. Rarely, a person with strep throat can develop a rash.
  6. If a you have a runny nose, constant sneezing and coughing, it actually is less likely that you have strep throat.


Just about any painful sore throat is caused by strep. See Answer

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 a person does not have strep throat and touches 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 with 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 .

  1. Have a fever over 102 F or 38.8 C
  2. Are dehydrated and have an associated headache, abdominal pain and/or nausea and vomiting.
  3. 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.


Sore Throat or Strep Throat? How to Tell the Difference See Slideshow

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Medically Reviewed on 10/5/2018

Khan, ZZ. et al. "Group A Streptococcal Infections." Medscape. Updated: Sep 07, 2018.