What does the antistreptolysin O (ASO) titer test determine?

The antistreptolysin O (ASO) titer test is specifically designed to measure the presence of antibodies against streptolysin O, a substance produced by Group A Streptococcus bacteria. A significant increase in these antibodies indicates that a recent infection has occurred, typically within the past few weeks. This test is commonly utilized in evaluating conditions such as rheumatic fever or post-streptococcal glomerulonephritis, both of which can develop following a strep throat infection.

The connection between elevated ASO titers and recent strep infections makes this test a valuable tool for healthcare providers in diagnosing and managing complications that may arise from such infections. Understanding this relationship emphasizes the relevance of the ASO titer in clinical practice and its role in guiding treatment decisions.