Menu   WellSpan Health

Health Library

Health Library

Beta Hemolytic Streptococcus Culture (Throat)

Does this test have other names?

Strep test, throat culture, Streptococcal screen

What is this test?

This test looks for the bacteria that cause strep throat. This condition causes a severe sore throat and makes it painful to swallow. It's important to detect and treat strep throat as soon as possible because it can progress to more serious illnesses, such as rheumatic fever.

The bacteria most likely to cause strep throat and bacterial sore throats in general are called Group A beta-hemolytic Streptococcus pyogenes (GABHS).

This test is a highly reliable way to diagnose strep throat because it has a sensitivity of 90% to 95%. But it's not used as commonly as the rapid antigen test because results for the throat culture are usually not available until 24 to 48 hours later.

Why do I need this test?

You may need this test if you have symptoms of strep throat, including:

  • Sore throat. The soreness can begin suddenly and cause severe pain when you swallow.

  • Fever. Temperatures in adults are usually 101°F (38.3°C) or higher.

  • Chills

  • Headache, nausea, and vomiting

  • Mild neck stiffness

  • Appetite loss

  • Swollen or enlarged lymph nodes in the neck

  • Swollen, red tonsils. Sometimes they have streaks of pus or white patches.

  • Rash or body aches

  • Small red spots on the roof of your mouth, in the back on the soft or hard palate

You may also have this test if your tonsils are painfully enlarged and your breath smells very bad.

Strep throat is treated with antibiotics. Starting antibiotics right away eases symptoms and can reduce the time you are contagious from 1 week to 1 day. Treatment also prevents rheumatic fever if taken within 10 days after symptoms begin.

What other tests might I have along with this test?

Your healthcare provider may also order these tests:

  • Rapid antigen test

  • Clinical prognostic score for GABHS, a score that helps prevent overuse of antibiotics for sore throats 

What do my test results mean?

Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your healthcare provider.

Normal results are negative, meaning you don't have strep throat. If your test result is positive, you almost certainly have strep throat caused by GABHS.  If your sore throat lasts longer than a week, you probably have a different illness.

If your test is positive, you should stay home from work or school until you have been taking your antibiotics for 24 hours. It is important to do this so the infection won’t be spread  to others. You should start feeling better within 1 to 2 days after starting the antibiotics.

Be sure to finish the entire prescription even though you are feeling better.

How is this test done?

The test requires a sample from your throat. Your healthcare provider will take the sample by swabbing both of your tonsils.

Does this test pose any risks?

The swabbing may cause a slight discomfort.

What might affect my test results?

Taking antibiotics can affect your results.

How do I get ready for this test?

You don't need to prepare for this test. But be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.  

Beta Hemolytic Streptococcus Culture (Throat) - WellSpan Health

Author: Fisher, Steve
Online Medical Reviewer: Fraser, Marianne, MSN, RN
Online Medical Reviewer: Sather, Rita, RN
Last Review Date: 2015-10-06T00:00:00
Last Modified Date: 2015-10-16T00:00:00
Published Date: 2015-10-16T00:00:00
Last Review Date: 2012-06-13T00:00:00
© 2015 WellSpan Health. All Rights Reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

I would like to:

Are you sure you would like to cancel?

All information will be lost.

Yes No ×

About the provider search

This search will provide you with WellSpan Medical Group and Northern Lancaster County (Ephrata) Medical Group primary care physicians and specialists. If we don’t have a WellSpan Medical Group physician to meet your criteria, the search will expand to include community physicians who partner with WellSpan Medical Group physicians through the WellSpan Provider Network or provide care to patients on the Medical Staffs of WellSpan’s Hospitals.


Schedule Your Next Appointment Online with MyWellSpan

Use your MyWellSpan patient portal any time to view available appointments, and pick the date and time that best suits your schedule.

Go to MyWellSpan

New to this practice?

If you don't have a WellSpan primary care provider and would like to schedule a new patient appointment with a provider who is accepting patients, just log into your MyWellSpan account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to see the offices that are accepting new patients in relation to your zip code. If you are not enrolled in MyWellSpan, go to, call 1-866-638-1842 or speak with a member of the staff at a participating facility to sign up. New patient scheduling not available at all practices/programs.

Already a patient at this practice?

If you already have a relationship with a WellSpan practice, simply log into your account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to schedule an appointment with any provider or practice that already counts you as a patient. Online scheduling varies by practice/program.