Strep A Antigen Screen, Throat Swab

Collect sample as follows using a double-swab transport (supplied by laboratory):  NOTE:  Only polyester or rayon tipped sterile swabs with plastic shafts should be used for collection.  Swab transport system containing liquid Stuart’s or liquid Amies media can be used for collection.  If swab transport has a preservative ampule, do not crush the ampule. 

1. Remove cap with swabs from tube.
2. Tilt patient’s head back to assist opening mouth as wide as possible.
3. Depress tongue with a tongue depressor to ensure swabs do not touch tongue.
4. Do not swab throat in cases of acute epiglotittis.
5. In one continuous motion, swab the posterior pharynx, both tonsils, and any area of inflammation, ulceration or exudation using both swabs.
6. Place swabs back into transport tube.
7. Label specimen with patient information, specimen source, and date and time of collection.
8. Transport to the laboratory at room temperature.  If a delay of greater than 4 hours is expected the specimen should be refrigerated.

None

Negative

All negative Group A Strep screens will automatically be reflexed to a Group A Strep culture screen at an additional charge.

• The accuracy of the test depends on the quality of the swab sample.  False negative tests may result from improper sample collection or storage, and low antigen concentration at the time of collection.
• Calcium alginate, cotton tipped, or wooden shaft swabs.
• Swab transport media containing charcoal or agar.
• In rare cases, test specimens heavily colonized with Staphylococcus aureus can yield false positive results.

Improper specimen collection or transport.
Calcium alginate, cotton tipped, or wooden shaft swabs.
Swab transport media containing charcoal or agar.