How long after antibiotics is strep no longer contagious

Strep throat is an infection of the throat and tonsils. It’s caused by a type of bacteria called group A Streptococcus (GAS).

It’s a highly contagious bacterial infection, and it can make your throat very sore and scratchy.

Read on to learn more about how strep throat is spread, how long it’s contagious, and what you can do to reduce your risk for the condition.

GAS bacteria can spread from person to person through contact with respiratory droplets from a person with strep throat. These droplets may be spread when a person with strep throat coughs or sneezes.

If you’re exposed to these droplets and then touch your mouth, nose, or eyes, you may contract strep throat. You may also get the infection if you:

• share food or a beverage with someone who has strep throat
• come into contact with a contaminated object, such as a faucet or doorknob

If you’ve been infected with strep, it can take two to five days for you to develop symptoms.

If you’ve been exposed to the bacteria, you can be contagious a few days before symptoms start.

If you’re treated with antibiotics, you’ll remain contagious until you’ve been on antibiotics for at least 24 hours. If you don’t seek treatment, you’ll remain contagious for 2 to 3 weeks after contracting the infection.

Strep throat is most common in school-age children. According to the Centers for Disease Control and Prevention (CDC), up to 30 percent of children with a sore throat have strep throat. Only 10 percent of adults with a sore throat have strep throat.

Adults who are frequently around school-age children have a higher risk of getting strep throat. Since strep throat is very contagious, being in crowded places, such as schools or daycare centers, can increase your risk of becoming sick.

You can get strep throat at any time of the year, but it’s generally more prevalent in the late fall or early spring.

Recurring infections

Even if you’ve had strep throat before, you can get it again. Some children have recurring strep throat, contracting the disease multiple times in a year.

In the case of recurring infections, your doctor may recommend tonsil removal to help decrease the frequency of strep throat infections. This procedure is called a tonsillectomy. However, you can still get strep throat even after your tonsils have been removed.

If you suspect that you have strep throat, you should see your doctor in order to get tested and begin treatment. Penicillin or amoxicillin are typically used to treat strep throat. If you’re allergic to penicillin, other antibiotics can be used.

Antibiotics may help you feel better faster. They can also shorten the amount of time that you’re contagious.

Most people are no longer contagious after they’ve taken antibiotics for at least 24 hours. Be sure to finish your entire course of antibiotics, though (unless your doctor tells you otherwise).

In addition to antibiotics, your doctor may recommend over-the-counter (OTC) medications such as ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) to help with your symptoms.

If you receive antibiotic treatment for your strep throat, your illness may only last for one to three days.

If left untreated, recovery will take longer, and your risk for developing complications will increase. Additionally, without treatment, you can still be contagious for several weeks, even after you stop feeling sick.

Follow these tips to help prevent the spread of strep throat:

• Clean your hands properly and regularly. Be sure to use an alcohol-based hand sanitizer or soap and warm water.
• Clean surfaces in your house if you, or someone in your house, has strep throat. Bacteria can survive for short periods of time on household items, such as doorknobs and tabletops.
• If you live with or care for someone with strep throat, be sure to wash your hands frequently. Also avoid touching your face, nose, and mouth.
• Avoid contact with anyone who has strep throat until they’ve been on antibiotics for at least 24 hours.
• Don’t share food, drinks, or eating utensils with others. Additionally, avoid sharing personal items, such as toothbrushes.
• If you have strep, be sure to cover your mouth when you cough or sneeze. Carry disposable tissues with you. If you don’t have a tissue, sneeze into the crook of your elbow instead of into your hand.
• If you have strep throat, be aware that you’re contagious as long as you have symptoms, and you should stay home from work or school. Once you start taking antibiotics, you should stay home until you’ve been on them for at least 24 hours.

Page last reviewed: 25 June 2020
Next review due: 25 June 2023