Antistreptolysin O Aso Serum

Why is ASO done?

The ASO Titer Test is performed:

·         To help determine if conditions like rheumatic fever or glomerulonephritis have occurred as complications of a Streptococcus infection

·         To determine the presence of a Streptococcus infection in case the patient has received antibiotics

What does ASO Measure?

The ASO Titer Test detects and measures the level of ASO in blood to determine the presence of an infection by Group A Streptococcus bacteria. Streptococcus pyogenes or Group A Streptococcus is a bacteria which causes a number of infections like throat infections, skin infections like pyoderma, etc. These infections are easily recognizable and treated with the help of antibiotics. However, if the Streptococcus infection is left untreated or is treated improperly, it may lead to complications like rheumatic fever, glomerulonephritis, scarlet fever, heart and kidney damage, joint inflammation, swelling, etc.

Symptoms caused by an infection of Group A Streptococcus bacteria are caused mainly due to a toxin called Streptolysin O which is secreted by these bacteria. The body produces antibodies against Streptolysin O called Antistreptolysin O (ASO). Production of ASO antibodies by the body can begin anytime from a week to a month after an infection. Levels peak after about 3 to 5 weeks after the condition develops, after which they slowly taper off as the condition resolves. Increase in ASO levels is greater in case of throat infections than in skin infections.