What is ASO Qualitative Test?
ASO (Anti-Streptolysin O) antibodies are produced by immune system in response to streptolysin O that is secreted by group A Streptococcus bacteria. These bacteria are associated with various infections of skin and throat including strap throat, scarlet fever and rheumatic fever. Generally, the infections caused by the group A streptococcus bacteria are mild but if left untreated can cause severe complications such as Inflammation of kidney, toxic shock syndrome, necrotizing fasciitis; a condition when the limbs are severely scarred or may cause loss of limb, and sepsis.
An ASO qualitative test is the analysis of the ASO antibodies in the blood to identify if an individual has had a streptococcal infection recently and if they are enough to fight against an infection.
How is the Test Performed?
The ASO qualitative is a straightforward blood test.
Preparation
- Fasting of approximately 6 hours is required for the test.
- Stay hydrated so that the blood can be drawn easily.
- Discuss with your healthcare provider about any medication you are taking as it may interfere with the test result.
- Stay calm before the test to ensure a smooth and stress-free procedure.
Collection
- Blood is collected through the process of venipuncture.
- The blood is drawn from the vein using a needle.
- The sample is then transferred into the tube to prevent sample degradation and contamination.
Lab Analysis
- Once the laboratory receives the sample, the sample is analyzed for the presence of ASO antibodies by advanced immunological assay such as latex agglutination and turbidimetric immunoassay.
What are the symptoms that prompt this test?
ASO qualitative test is recommended for individuals in which the healthcare provider suspects a recent or a past infection or complications related to it. The symptoms that the healthcare provider looks for are mentioned below;
Symptoms in Children and Adolescents
- Sore throat
- Swallowing difficulties
- Fever
- Appearance of red or white patches on the tonsils.
- Joint pain or swelling
- Fatigue without known reason indicating rheumatic fever
Symptoms in Adults
- Persistent sore throat
- Symptoms of kidney damage such as bloody urine, edema, and high blood pressure
- Unusual skin rashes
- Joint Pain
- Fever lasting for more than 3 days
What are Normal Ranges for This Test?
ASO qualitative test varies according to the age, gender and overall health of the individual and is given as a positive or a negative test result.
- Children under 5 years – Typically negative or low antibodies
- Children above 5 years or adolescents – Typically higher but should remain below the diagnostic threshold.
- Adults – Negative or within normal limits
**The antibodies remain in the bloodstream after weeks of infection thus a positive result is not always indicative of an active infection and additional tests are required.
What Happens if Test Results Show Abnormal Levels?
Abnormal levels of ASO qualitative test indicate the presence of an active streptococcal infection. High levels of antibody require further testing to confirm the presence of the disease and rule out the complications. The healthcare provider may suggest the following;
Elevated levels of ASO antibody
- Throat culture test
- Antigen detection test
- Echocardiograms
- Urinalysis
Treatment
- Antibiotics
- Anti-inflammatory medications
- Corticosteroid
- Regular monitoring for disease management
Assessment of regular antibody presence in the blood is crucial for effective treatment and management of the streptococcal infection.
