Antistreptolysin O (ASO) Body Fluids Test

ASO Body Fluids Test Overview

The antistreptolysin O test or ASO test is used by doctors to measure the antibodies in your body fluids against a toxin known as streptolysin O. Group A streptococcus bacteria produces the toxin streptolysin O, which has the potential to cause a streptococcal infection. 

The ASO body fluids test checks your body for antibodies that your immune system has produced against this toxin to prevent any resulting infection. The goal of the antistreptolysin o body fluids test is to monitor conditions caused by a streptococcal infection.

When is an ASO Body Fluids Test Prescribed?

The ASO body fluids test is recommended by doctors for patients that have symptoms that would indicate a streptococcal infection. Here are some of the reasons this test is prescribed.

• The ASO test is prescribed in case doctors suspect streptococcal infections like scarlet fever and strep throat
• Rheumatic fever is a rare but possible complication of streptococcal infections and can be a serious threat to a patient’s health. The ASO test is used to study the risk of rheumatic fever of patients.
• This test is also performed to study a patient’s immune history and whether they have been infected by Group A Streptococcus in the past.

Components of An ASO Body Fluids Test

The normal range for an ASO body fluids test differs depending on the age of the patient. For adults, the normal range is less than 200 while for children below the age of 5, the normal range is less than 100. 

ASO levels are detectable in your blood for up to a few months after an infection, so doctors often use this test to check if you have had infections in the past or not. Elevated levels of this antibody in your body fluids can indicate conditions like scarlet fever.

Procedure And Prerequisites

As a body fluids test the procedure for procuring the sample is different for the body fluid being tested. However, the general procedure involves inserting a needle through the skin to collect the required body fluid samples for testing. There are no special prerequisites required for an ASO body fluids test.