How Long Is Strep Contagious

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How Long Is Strep Contagious
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Many readers are interested in the following topic: Is Strep Throat Contagious. We are happy to note, that our authors have already studied the modern research about the topic you are interested in. Based on the information provided in the latest medical digests, modern research and surveys, we provide extensive answer. Keep reading to find out more.

Additionally, it is essential that you discuss with your doctor when you can resume daily activities, such as school or work, without running the risk of infecting others. If your doctor prescribes you antibiotics, make sure to complete your medication even if you’re feeling better to prevent the growth of antibiotic-resistant bacteria, which can be harmful to the body.

Strep Throat: All You Need to Know

Doctor examining patient.

Worried your sore throat may be strep throat? Doctors can do a quick test to see if a sore throat is strep throat. Antibiotics can help people with strep throat feel better faster and prevent spreading it to others.

On This Page

  • Bacteria cause strep throat
  • How you get strep throat
  • Pain, fever, but no cough is common
  • Some people are at increased risk
  • A simple test gives fast results
  • Antibiotics are used for treatment
  • Not everyone needs antibiotics
  • Serious complications are not common
  • Protect yourself and others

Bacteria cause strep throat

Viruses cause most sore throats. However, strep throat is an infection in the throat and tonsils caused by bacteria called group A Streptococcus (group A strep).

How you get strep throat

Group A strep bacteria are very contagious. Generally, people spread the bacteria to others through

  • Respiratory droplets
  • Direct contact

Rarely, people can spread group A strep bacteria through food that is not handled properly (visit CDC’s food safety page).

It usually takes two to five days for someone exposed to group A strep bacteria to become ill with strep throat.

Respiratory droplets

Group A strep bacteria often live in the nose and throat. People who are infected spread the bacteria by talking, coughing, or sneezing, which creates respiratory droplets that contain the bacteria.

People can get sick if they:

  • Breathe in respiratory droplets that contain the bacteria
  • Touch something with those droplets on it and then touch their mouth or nose
  • Drink from the same glass or eat from the same plate as a person infected with group A strep bacteria

Direct contact

People can also spread group A strep bacteria from infected sores on their skin. Other people can get sick if they:

  • Touch sores on the skin caused by group A strep bacteria (impetigo) or come into contact with fluid from the sores

It is important to know that some infected people do not have symptoms or seem sick. People sick with strep throat are much more contagious than those who do not have symptoms.

Signs and symptoms of strep throat usually include a sore throat that starts quickly; pain with swallowing; fever; red and swollen tonsils, sometimes with white patches or streaks of pus; tiny red spots on the roof of the mouth; and swollen lymph nodes in the front of the neck. Signs and symptoms of strep throat typically do not include cough, runny nose, hoarseness, or conjunctivitis (pink eye).

A sore throat that starts quickly, pain with swallowing, and fever are some of the common signs and symptoms of strep throat.

Pain, fever, but no cough is common

In general, strep throat is a mild infection, but it can be very painful. The most common symptoms of strep throat include:

  • Sore throat that can start very quickly
  • Pain when swallowing
  • Fever
  • Red and swollen tonsils, sometimes with white patches or streaks of pus
  • Petechiae — pronounced pi-TEE-kee-eye — on the soft or hard palate (tiny, red spots on the roof of the mouth)
  • Swollen lymph nodes in the front of the neck

Other symptoms may include a headache, stomach pain, nausea, or vomiting — especially in children. Someone with strep throat may also have a rash; it is known as scarlet fever.

Some symptoms suggest a viral cause rather than group A strep

The following symptoms suggest a virus is the cause of the illness instead of strep throat:

  • Cough
  • Runny nose
  • Hoarseness (changes in your voice that make it sound breathy, raspy, or strained)
  • Conjunctivitis (pink eye)

Strep throat: More common in children

  • Up to 3 in 10 children with a sore throat have strep throat
  • About 1 in 10 adults with a sore throat has strep throat

Some people are at increased risk

Anyone can get strep throat, but there are some factors that can increase the risk of getting this common infection.

Age

Strep throat is more common in children than adults. It is most common in children 5 through 15 years old. It is very rare in children younger than 3 years old.

Adults who are at increased risk for strep throat include:

  • Parents of school-aged children
  • Adults who are often in contact with children

Group settings

Close contact with another person with strep throat is the most common risk factor for illness. For example, if someone has strep throat, the bacteria often spread to other people in their household.

Infectious illnesses tend to spread wherever large groups of people gather. Crowded settings can increase the risk of getting a group A strep infection. These settings include:

  • Schools
  • Daycare centers
  • Military training facilities

A simple test gives fast results

A doctor will determine what type of illness you have by asking about symptoms and doing a physical exam. If they think you might have strep throat, they will swab your throat to test for strep throat. There are two types of tests for strep throat: a rapid strep test and throat culture.

Rapid strep test

A rapid strep test involves swabbing the throat and running a test on the swab. The test quickly shows if group A strep bacteria are causing the illness.

  • If the test is positive, doctors can prescribe antibiotics.
  • If the test is negative, but a doctor still suspects strep throat, then the doctor can take a throat culture swab.

Throat culture

A throat culture takes time to see if group A strep bacteria grow from the swab. While it takes more time, a throat culture sometimes finds infections that the rapid strep test misses.

Culture is important to use in children and teens since they can get rheumatic fever from an untreated strep throat infection. For adults, it is usually not necessary to do a throat culture following a negative rapid strep test. Adults are generally not at risk of getting rheumatic fever following a strep throat infection.

Antibiotics are used for treatment

Doctors treat strep throat with antibiotics. Benefits of antibiotics include:

  • Decreasing how long someone is sick
  • Decreasing symptoms (feeling better)
  • Preventing the bacteria from spreading to others
  • Preventing serious complications like rheumatic fever

Someone with strep throat should start feeling better in just a day or two after starting antibiotics. Call the doctor if you or your child are not feeling better after taking antibiotics for 48 hours.

When to return to work, school after illness

People with strep throat should stay home from work, school, or daycare until they:

  • No longer have a fever
  • Have taken antibiotics for at least 12 hours

Antibiotic dos and don’ts

  1. Do take the prescription exactly as the doctor says to.
  2. Don’t stop taking the medicine, even if you or your child feels better, unless the doctor says to stop.

You can find more guidance on taking antibiotics on CDC’s Antibiotic Do’s & Don’ts Page.

Not everyone needs antibiotics

Someone who tests positive for strep throat but has no symptoms (called a “carrier”) usually does not need antibiotics. They are less likely to spread the bacteria to others and very unlikely to get complications.

If a carrier gets a sore throat illness caused by a virus, the rapid strep test can be positive. In these cases, it can be hard to know what is causing the sore throat.

If someone keeps getting a sore throat after taking the right antibiotics, they may be a strep carrier and have a viral throat infection. Talk to a doctor if you think you or your child may be a strep carrier.

Serious complications are not common

Complications can occur after a strep throat infection. This can happen if the bacteria spread to other parts of the body.

Complications can include:

  • Abscesses (pockets of pus) around the tonsils or in the neck
  • Swollen lymph nodes in the neck
  • Sinus infections
  • Ear infections
  • Rheumatic fever (a disease that can affect the heart, joints, brain, and skin)
  • Post-streptococcal glomerulonephritis (a kidney disease)

Someone helping a young boy wash his hands with soap and water.

Wash your hands often to help prevent germs from spreading.

Protect yourself and others

People can get strep throat more than once. Having strep throat does not protect someone from getting it again in the future. While there is no vaccine to prevent strep throat, there are things people can do to protect themselves and others.

Good hygiene

The best way to keep from getting or spreading group A strep is to wash your hands often. This is especially important after coughing or sneezing and before preparing foods or eating.

To prevent group A strep infections, you should:

  • Cover your mouth and nose with a tissue when you cough or sneeze.
  • Put your used tissue in the waste basket.
  • Cough or sneeze into your upper sleeve or elbow, not your hands, if you don’t have a tissue.
  • Wash your hands often with soap and water for at least 20 seconds.
  • Use an alcohol-based hand rub if soap and water are not available.

You should also wash glasses, utensils, and plates after someone who is sick uses them. These items are safe for others to use once washed.

Antibiotics

Antibiotics help prevent someone with strep throat from spreading the bacteria to others.

Is Strep Throat Contagious?

Chris Vincent, MD, is a licensed physician, surgeon, and board-certified doctor of family medicine.

Strep throat is an infection in the throat and tonsils caused by bacteria called group A Streptococcus, also known as Streptococcus pyogenes. This group of bacteria can also cause other infections, including scarlet fever, pneumonia, sepsis, toxic shock syndrome, and necrotizing fasciitis, which can be life-threatening.

While strep throat only accounts for a small number of sore throats, it is generally more common in children (ages 5 to 15) than adults. This article will explore how strep throat is contagious, its causes, risk factors, treatment, and prevention.

Girl with sore throat talks to healthcare provider

Is Strep Throat Contagious?

Strep throat is highly contagious and can spread quickly from person to person through close contact. Individuals with strep throat can be contagious for a few days before they start showing symptoms. This means that someone who has not gotten sick yet can spread the disease.

How Do I Know If I Have Strep Throat?

Common symptoms of strep throat include a sore throat that comes on quickly and causes pain with swallowing. Other signs include fever, red and swollen tonsils (sometimes with white patches or a streak of pus), swollen lymph nodes in the neck, petechiae (tiny red spots on the roof of the mouth), and more.

Causes

Strep throat is caused by a group of bacteria known as Streptococus pyogenes. It is typically transmitted from person to person through saliva or secretions that contain the bacteria. People can also pass strep throat through coughing, sneezing, and touching people or contaminated objects (doorknobs, door handles, utensils, etc.).

The bacteria are less commonly transmitted through food or water. Since you are unlikely to get strep throat from animals, the risk of getting infected from pets is very low.

Risk Factors

Some factors can increase your risk of contracting strep throat. They include:

  • Young age: Strep throat occurs frequently in children ages 5 to 15 and is rare in children under 3).
  • Close contact/spending time in crowded settings: This includes spending time with someone who has strep throat in schools, day care centers, or large venues.
  • The time of year: Strep throat can occur year-round, but it has seasonal variations. Infections are more common in late winter and early spring.
  • Genetics: According to a 2019 study, researchers found that kids with recurring strep throat tended to have smaller germinal centers in their tonsils, which usually recognize and fight infections. They also were more likely to have family members who had tonsillectomies (surgical removal of the tonsils).
  • Weakened immune system: This increases the susceptibility for people to get strep throat.

Treatment

Antibiotics are the most commonly used medications to treat bacterial infections by preventing them from growing or killing them. To treat strep throat, your healthcare provider may prescribe you penicillin or amoxicillin.

However, if you are allergic to penicillin your doctor may prescribe a cephalosporin such as Keflex (cephalexin) or medication from a different “family” of antibiotic drugs that is unlike penicillin.

Additionally, someone who tests positive for strep throat but has no symptoms (called a carrier) does not typically need antibiotics. This is because carriers are less likely to spread the bacteria to others and very unlikely to get complications.

However, always consult your healthcare professional if you believe you or someone you know may be a carrier for strep throat to determine the best course of treatment.

The list below highlights some of the benefits of antibiotics. They include:

  • Decreasing how long someone is sick
  • Decreasing symptoms
  • Preventing the bacteria from spreading to others
  • Preventing serious complications such as rheumatic fever

It is essential to finish your course of antibiotics even if you are feeling better, as the remaining bacteria can continue to multiply. When this happens, bacteria can become resistant to the antibiotics, and cause further harm to the body. In some cases, it can develop into sepsis (blood infection), which is a life-threatening condition.

Complications of Strep Throat

Although uncommon, complications can occur after a strep throat infection. This can happen if the bacteria spread to other parts of the body. Complications can include:

  • Abscesses (pockets of pus) around the tonsils
  • Swollen lymph nodes in the neck
  • Sinus infections
  • Ear infections
  • Rheumatic fever: An inflammatory condition of the heart, joints, brain, and skin that can develop if a group A Streptococcus infection is not fully treated
  • Post-streptococcal glomerulonephritis: A rare kidney disease

When to See a Doctor

While strep throat is not usually dangerous, it can sometimes cause medical emergencies. However, this is rare. Seek medical care immediately if you have strep throat and experience the following signs and symptoms:

  • Trouble breathing or shortness of breath
  • Dizziness, feeling faint, or passing out
  • Blue or pale lips or fingers
  • Trouble swallowing

Prevention

People can get strep throat more than once. Having strep throat does not protect someone from getting it again in the future. While there is no vaccine to prevent strep throat, there are things people can do to protect themselves and others. These include:

  • Practicing good hygiene: This includes washing your hands often (with soap and warm water for at least 20 seconds), especially after coughing or sneezing and before preparing food or eating. You should also wash glasses and utensils after a person who is sick uses them. Practicing good hygiene is the best way to keep from getting or spreading group A strep.
  • Stay home and take your antibiotics if you have strep throat: Your healthcare provider will likely prescribe antibiotics for strep throat. Stay home from work or school until you no longer have a fever and have taken antibiotics for at least 12 hours.

Take Your Full Antibiotic Prescription

Do not stop taking antibiotics even if you are feeling better (unless advised to do so by your healthcare provider). This prevents the growth of antibiotic-resistant bacteria.

Summary

Strep throat is an infection in the throat and tonsils caused by group A Streptococcus bacteria. It is highly infectious and can be transmitted from person to person through close contact or by touching infected surfaces. It also produces painful symptoms such as sore throat, red and swollen tonsils, fever, and swollen lymph nodes.

There are many risk factors for strep throat, including age, the time of year, genetics, a weakened immune system, and if you do not finish your course of antibiotics. If you have strep throat, antibiotics are the most commonly used medications your healthcare provider will prescribe.

A Word From Verywell

If you have strep throat, it is crucial for you to get plenty of rest, stay hydrated, and eat well, even if swallowing is painful. This will ease the recovery process and help you feel better.

Additionally, it is essential that you discuss with your doctor when you can resume daily activities, such as school or work, without running the risk of infecting others. If your doctor prescribes you antibiotics, make sure to complete your medication even if you’re feeling better to prevent the growth of antibiotic-resistant bacteria, which can be harmful to the body.

That said, you should not expect to experience serious long-term consequences with strep throat, and you should expect to improve within a week. If your symptoms do not improve, get worse, or if you are not feeling better after taking antibiotics after 48 hours, consult your doctor as soon as possible.

Frequently Asked Questions

How long does strep throat last?

Once a person has contracted the group A Streptococcus bacteria, they can become ill after roughly two to five days. A person will begin to feel better after taking antibiotics for one to two days. If you do not feel better after taking antibiotics for 48 hours, consult your doctor.

What does strep throat look like?

People with strep throat have red and swollen tonsils (sometimes with white patches or streaks of pus) that can be very painful. Additionally, tiny red spots on the area at the back of the roof of the mouth may also be visible.

How long is strep throat contagious?

You can stay contagious for up to a month if you don’t get treated. However, you are no longer contagious after 24 to 48 hours of antibiotic treatment.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

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  2. Centers for Disease Control and Prevention. Strep throat: all you need to know.
  3. Dan J, Havenar-Daughton C, Kendric K, et al. Recurrent group A Streptococcus tonsillitis is an immunosusceptibility disease involving antibody deficiency and aberrant TFHcells. Sci Transl Med. 2019;11(478):eaau3776. doi:10.1126/scitranslmed.aau3776
  4. Sykes EA, Wu V, Beyea MM, Simpson MTW, Beyea JA. Pharyngitis.Canadian Family Physician. 2020;66(4):251-257.
  5. Centers for Disease Control and Prevention. Rheumatic fever: all you need to know.
  6. Centers for Disease Control and Prevention. Post-streptococcal glomerulonephritis: all you need to know.