Antistreptolysin O Titer (ASO)

Antistreptolysin O Titer (ASO) is a blood test that measures the antibodies against anti-streptolycin O a substance produced by a group of streptococcus bacteria. is not used to diagnose a current strep infection, such as strep throat. When you come into contact with harmful bacteria your body produces antibodies to defend against these bacteria.

Usually, if you have a strep infection like strep throat, you receive antibiotics that kill the strep bacteria. However, some people don’t have any symptoms during a strep infection and may not know they need treatment. When this happens, an untreated infection can lead to future complications. These complications are known as post-streptococcal complications.

Is This Test Have Other Name

Antistreptolysin O Titer, ASOT, ASO Titer,

How The Test Performed

A Blood sample is needed.

Why The Test Performed

If you have a strep infection with the bacteria of Streptococcus, help diagnose complications resulting from a strep infection such as Rheumatoid fever, glomerulonephritis, or kidney disease. You may need an ASO Titer blood test if you have complications.

Why Need This Test

If you have symptoms, one of the following complications,

1. Fever
2. Chest pain
3. Fatigue
4. Bacterial endocarditis
5. Strep throat
6. Shortness of breath
7. Rheumatic fever which can affect the Joints or bones
8. Tonsils
9. Sinuses
10. Middle Ear Infection
11. Symptoms such as fluid accumulation (edema)
12. A kidney problem called glomerulonephritis
13. Dark urine that is associated with glomerulonephritis

What Does the Result Mean

A negative result means you do not have a step infection. But you need to repeat the test after 2 to 4 weeks if you have symptoms. A positive test result means you have a strep infection even if you have no symptoms. If the results of your tests show that your ASO antibodies are increasing, your infection is likely recent. Declining antibody levels suggest that your infection is getting better.