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Streptococcus Group A Antigen Rapid Test (Throat Swab)

Published: August 9, 2026Updated: August 16, 2026

This test checks for the presence of Group A Streptococcus bacteria in your throat, which can cause infections like strep throat.

Quick summary

["A rapid throat swab test to detect Group A strep bacteria, helping diagnose infections quickly."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
108600-8
Short code
S pyo Ag Msmt Throat
Synonyms
S pyo Ag Msmt Throat
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms like sore throat, fever, swollen tonsils, or redness in your throat. It’s often used to quickly rule out strep throat, especially in children or adults with sudden onset of symptoms.

How the Test Works

A healthcare provider will take a swab from the back of your throat and apply it to a test strip. The test detects Group A Streptococcus antigens, which appear within minutes. Results are typically available in 5 to 15 minutes.

What to Expect Before the Test

No special preparation is needed. You may swallow saliva before the swab to help it reach the throat area. Avoid eating or drinking for 15 minutes before the test if instructed.

What to Expect During the Test

The swab is gently inserted into your throat, and you may feel a slight tickle or discomfort. It usually takes less than a minute. You can breathe normally during the procedure.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Positive results indicate the presence of Group A Streptococcus, which can cause serious infections if untreated. Treating strep throat early with antibiotics can prevent complications like rheumatic fever or kidney issues. Negative results mean no Group A strep bacteria were detected in this sample, but symptoms may still be due to other causes like viral infections.

Short name

Group A Strep Swab Test

Frequently asked questions

How accurate is this test?
This rapid test is highly accurate for diagnosing Group A strep throat. However, it may not detect all cases, especially if the bacteria are not actively present in your throat at the time of testing. Follow-up testing or culture may be needed if symptoms persist.
What if I get a positive result?
If your test is positive, your healthcare provider will likely prescribe antibiotics to treat the infection. It’s important to finish the full course of medication to prevent complications. Rest, stay hydrated, and avoid spreading germs to others.
Can I have this test if I’m allergic to penicillin or other antibiotics?
Yes, you can still have this test. If you have an allergy to antibiotics, let your healthcare provider know. They may recommend an alternative antibiotic if needed, but the test itself is not affected by allergies to medications.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy