Streptococcal serology – ASO, Blood

Diagnostic Use

Timing of streptococcal serology testing for evidence of preceding Group A streptococcal infection is important. Streptococcal antibodies rise during the first month after infection, plateau for 3-6 months before returning to normal levels at 6-12 months.

Department

Microbiology - Serology

Delphic Registration Code

STRP

Laboratory Handling

Phlebotomy

Serum only

Registration

Serum only

Laboratory

Serum only

Constituent Tests

• Streptococcal serology – Dnase, Blood

Synonyms

ASO
Dnase

Turnaround Time

4 days

Test Code

2449

Specimen Type

• Serum

Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Acceptable

• Serum (Red Cap)
• SST II (Gold Cap)

Preferred Sample Volume (ml)

10.0

Minimum Sample Volume (ml)

5.0

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Acceptable

• Serum (Red Cap)

Preferred Sample Volume (ml)

5.0

Minimum Sample Volume (ml)

2.0

Additional Specimen Information

Serum only

Aliquot Instructions

Sample Type

• Serum

Minimum Volume (ml)

0.5

Transport to Lab

Chilled (2 - 8 degrees Celsius)
If overnight - Chilled (2 - 8 degrees Celsius)

Additional Referral/Aliquot Information

Preferred aliquot serum 2 mL

Interpretation

The cutoff values for serological evidence of Group A streptococcal disease vary dependent on the individual assay used by the laboratory. The reported values may deviate from those stated in the Ministry of Health Rheumatic Fever guideline.

Interpret in conjunction with Anti-Dnase B result.

Reference Intervals

Reported as International Units per mL:

Normal ASO <200 for adults and <250 for school age children.

ASO                               DNASE B

<200 IU/ml                 <200 IU/ml                   ADULTS

<250 IU/ml                   <300 IU/ml                  School Age children

<100 IU/ml                    <300 U/ml                  Pre-school children

 

 

 

Test Method

Latex Turbidimetric Assay

Non-Funded Test Cost

$35.66 (Exclusive of GST)

Billing Code

2449

Onset date of illness desirable.

Contact Information

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