Strep test

Strep Test

A Strep Test is a diagnostic procedure used to determine the presence of Streptococcus pyogenes bacteria, commonly known as Group A Streptococcus (GAS), in a patient's throat. This bacterium is the most common cause of bacterial pharyngitis or "strep throat."

Procedure

The strep test is typically performed in a healthcare provider's office. The procedure involves using a sterile swab to collect a sample from the back of the patient's throat and tonsils. This sample is then tested for the presence of GAS bacteria. There are two main types of strep tests: the rapid antigen detection test (RADT) and the throat culture.

Rapid Antigen Detection Test (RADT)

The Rapid Antigen Detection Test (RADT) is a quick procedure that can produce results within minutes. It works by detecting antigens, substances that trigger an immune response, from the GAS bacteria in the patient's throat swab sample. While RADTs are highly specific, they are not as sensitive as throat cultures and may produce false-negative results.

Throat Culture

A throat culture is a more sensitive test that involves culturing the throat swab sample in a laboratory to see if GAS bacteria grow. Results are typically available within 24 to 48 hours. Throat cultures are considered the gold standard for diagnosing strep throat.

Indications

A strep test may be indicated if a patient presents with symptoms of strep throat, which can include a sore throat, fever, headache, and swollen lymph nodes. However, these symptoms can also be caused by viral infections, which are not treatable with antibiotics. Therefore, a strep test is necessary to confirm a diagnosis of strep throat and guide appropriate treatment.

Treatment

If a strep test is positive, the patient is typically prescribed antibiotics to treat the infection. Penicillin and amoxicillin are commonly used antibiotics for strep throat. It's important for patients to complete the full course of antibiotics to prevent complications, such as rheumatic fever and post-streptococcal glomerulonephritis.

See Also

• Pharyngitis
• Streptococcus pyogenes
• Rapid Antigen Detection Test
• Throat culture