Test Overview
Test Methodology

OSOM Ultra Strep A- immunochromatography for Strep A Antigen detection

Test Usage

Performed at authorized locations by point of care operators. Group A streptococcus is one of the most important causes of acute upper respiratory tract infection. Early diagnosis and treatment of Group A Streptococcal pharyngitis has been shown to reduce the severity of symptoms and further complications such as rheumatic fever and glomerulonephritis.

Reference Range *


* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

•For pediatric patients, negative tests must be confirmed by sending the specimen to the central Microbiology lab for testing. The Department of Pathology recommends confirmatory testing for all negative tests.
•Improperly collected throat swabs may lead to false negative results. The quality of the test depends on the quality of the sample; proper throat swabs specimens must be obtained. Negative results can occur from inadequate specimen collection or antigen levels which are below the detection limit of the test.
•The OSMO ultra strep A is a qualitative test for the detection of Group A streptococcal antigen. This test detects both viable and non-viable Group A strep and may yield a positive result in absence of a living organism.
•This test does not differentiate between carriers and acute infection.
•Pharyngitis may be caused by viral bacterial pathogens other than Group A strep.
•If the test result is inconsistent with clinical symptoms, a second throat swab should be collected for repeat testing.
• A clear background is an internal background negative procedural control . If no interfering substances are in the specimen and the test stick is working properly, the background will clear.

Test Details
Analytic Time

7 minutes

Soft Order Code
MiChart Code
Strep A Antigen, Point of Care (Clinic Performed)
Point of Care
Point of Care
Specimen Requirements
Collection Instructions

Collect specimen from the throat using the E swab:
1. Open the BD Eswab sample collection kit and removed the tube and swab applicator.
2. Collect the specimen from the patient, swabbing both tonsillar pillars and oropharynx. During specimen collection, when handling the swab applicator do not touch the area below the marked breakpoint indication line.(Red line) Take care to avoid the teeth, gums, tongue or cheek surfaces. 3. Aseptically unscrew and remove the cap from the tube.
4. Insert the swab into the tube and bend the swab shaft at the breakpoint indicated by the colored line marked on the swab shaft against the tube break the shaft. Discard the broken handle part of the swab shaft into an approved medical waste disposal container.
5. Replace cap on the tub and secure tightly. The swab will center itself into the lid.
6. Label container with at least tow patient identifiers (Full Name and MRN). Lab- ready or demographic labels are preferred.

Additional Information

For more test specific information, please refer to the test procedure found on the Michigan Medicine POC website: https://www.pathology.med.umich.edu/point-of-care

CPT Code