✍️ Edited by Farhan Ahmed, Editor, MedTestBD · Last updated: August 2026
What is the ASO Titre Test?
The ASO Titre (Antistreptolysin O Titre) test measures the level of antibodies against streptolysin O — a toxin produced by Group A Streptococcus bacteria. When the body is infected by this bacteria (which causes strep throat), it produces ASO antibodies. An elevated ASO titre confirms a recent or past streptococcal infection and is used to diagnose complications that can develop weeks after the initial throat infection.
Why is the ASO Titre Test Done?
- To confirm a recent Group A Streptococcal infection, even when the throat infection itself has resolved
- To diagnose acute rheumatic fever — a serious complication of untreated strep throat that can damage the heart valves
- To diagnose post-streptococcal glomerulonephritis — kidney inflammation following a strep infection
- To investigate joint pain, fever, or heart symptoms appearing 2–4 weeks after a sore throat
- To monitor treatment response in patients with known rheumatic fever
Normal ASO Titre Levels
| Group | Normal (Negative) Range |
|---|---|
| Adults | Below 200 IU/mL |
| Children (school-age) | Below 320 IU/mL |
A single elevated result must be interpreted carefully — ASO can remain elevated for months after an infection without indicating active disease. A rising titre on repeat testing 2 weeks apart is more diagnostically significant than a single high value. Your doctor will interpret results alongside symptoms, CRP, and other inflammatory markers.
How to Prepare for the ASO Titre Test
- No fasting is required
- Inform your doctor if you are currently taking antibiotics — they can reduce ASO levels and affect the result
- Inform the doctor about any recent sore throat, fever, joint swelling, or skin rash in the past 2–6 weeks
- A simple blood sample is drawn from a vein in your arm
- The test is often repeated after 10–14 days to look for a rising or falling trend
ASO Titre Test Price in Bangladesh
ASO titre test prices vary between diagnostic centers across Bangladesh. Compare ASO titre test prices on MedTestBD →
Normal ranges cited on this page are based on MedlinePlus and WHO guidance. Prices are collected from public sources and may change — confirm with the facility before visiting. This information is for general reference only and is not medical advice. Always consult a qualified physician.
