What is the most commonly used serological indicator of recent streptococcal infection?

The most commonly used serological indicator of recent streptococcal infection is Antistreptolysin O (ASO). ASO is a specific antibody produced in response to streptolysin O, a toxin released by Group A Streptococcus that can cause tissue damage and contribute to the pathogenesis of infections.

When a person is infected with this strain of streptococcus, the immune system produces ASO antibodies, which can typically be detected in the blood around one to two weeks after the onset of the infection. A significant rise in ASO titers over time can indicate a recent infection, making it a valuable tool for clinicians in diagnosing conditions such as rheumatic fever and post-streptococcal glomerulonephritis that are associated with streptococcal infections.

While Anti-DNase B is another useful serological marker, it is not as commonly used as ASO for the initial detection of recent infections. Anti-streptokinase and Anti-M protein antibodies are also produced in response to streptococcal infections but are less commonly utilized in clinical practice for diagnosing recent infections. Thus, ASO remains the primary indicator used in serological testing for recent streptococcal infections