ASO Test: Understanding Strep Throat & Scarlet Fever Diagnosis

ASO stands for antistreptolysin O. It is a test used to measure the body's immune response to a bacterial infection caused by Streptococcus pyogenes, the bacteria that causes strep throat and scarlet fever. The ASO test measures the amount of antibodies in the blood that are directed against a protein produced by the bacteria, known as streptolysin O.

The ASO test is typically performed on a blood sample. The results of the test can help diagnose a current or recent streptococcal infection and can also be used to monitor the effectiveness of antibiotic treatment. Elevated ASO levels may indicate a current or recent streptococcal infection, but other conditions can also cause elevated levels, such as rheumatic fever and glomerulonephritis. Therefore, the ASO test should always be interpreted in the context of the patient's clinical presentation and other laboratory findings.