Your doctor will order the ASO test if you have symptoms of poststreptococcal complications. Such complications include:
- bacterial endocarditis
- rheumatic fever
- scarlet fever
- strep throat
Generally, an ASO test value below 200 is considered normal. In preschool-aged children, the test value should be less than 100. However, specific results will vary by laboratory. If your results show that your ASO value is elevated, you may have a post-streptococcal complication. Your doctor may repeat the test within 10 to 14 days to confirm your results. The body produces ASO antibodies within a week after infection with GAS. If both tests are negative, your symptoms are probably not caused by a Streptococcus infection. If the results of your tests show that your ASO antibodies are increasing, it is likely that your infection is recent. Declining antibody levels suggest that your infection is probably getting better.