Throat Culture: About This Test

What is it?

A throat culture is a test to find a bacterial or fungal infection in the throat.

Why is this test done?

A throat culture may be done to:

• Find the cause of a sore throat. Most sore throat infections are caused by a virus. A throat culture shows the difference between a bacterial infection and a viral infection. This can help guide treatment.
• Check a person who may not have any symptoms of infection but who carries bacteria that can spread to others. This person is called a carrier.

How do you prepare for the test?

• In general, there's nothing you have to do before this test, unless your doctor tells you to.
• Tell your doctor if you have recently taken any antibiotics.

How is the test done?

• You will be asked to tilt your head back and open your mouth as wide as you can.
• Your doctor will press your tongue down with a flat stick (tongue depressor) and then examine your mouth and throat.
• A clean cotton swab will be rubbed over the back of your throat, around your tonsils, and over any red areas or sores to collect a sample.
• The sample may also be collected using a throat washout. For this test, you will gargle a small amount of salt water and then spit the fluid into a clean cup. This method gives a larger sample than a throat swab. It may make the culture more reliable.

How long does the test take?

The test will take less than a minute.

What happens after the test?

• Results for a rapid strep test are available in 10 to 15 minutes. This test is only for bacterial infections caused by strep bacteria. This is the most common type of throat culture.
• Other throat culture test results for bacterial infections are ready in 1 to 2 days, depending on which bacteria are being tested for. Test results for a fungus may take about 7 days.

When should you call for help?

Call your doctor now or seek immediate medical care if:

• You have a new or higher fever
• You have a fever with a stiff neck or severe headache.
• You have new or worse trouble swallowing.
• Your sore throat gets much worse on one side.

Watch closely for changes in your health, and be sure to contact your doctor if:

• You do not start to feel better after 2 days (48 hours).
• You do not get better as expected.