Rapid Strep A Procedure

1. Specimen Collection

Collect a specimen with a sterile swab from the tonsils and/or the back of the throat. Take care to avoid teeth, gums, tongue, or cheek surfaces.

Use a sterile rayon or Dacron swab to collect specimens. Swabs with transport tubes containing liquid media can also be used. Modified Stuart’s Transport Media is an acceptable liquid media.

Do not use swabs that have cotton tips or wooden shafts. Do not use calcium alginate swabs. Do not use a collection system that contains charcoal or semisolid transport media.

Testing should ideally be performed immediately after the specimens have been collected. Swab specimens may be stored at room temperature for up to four hours prior to testing. The swabs and the test kit must be at room temperature before performing the test.

2. Quality Control

Internal Procedural Controls

The Strep A test provides three levels of procedural controls with each test run. For internal quality control, document these controls were OK with each patient test resulted in the EMR.

1. The color of the liquid changes from pink to light yellow as Reagent 2 is added to Reagent 1. This is an internal extraction reagent control. The color change means that you mixed the extraction reagents properly. The color change also indicates the reagents are functioning properly.
2. The pink Control Line is an internal control. The dipstick must absorb the proper amount of sample and the dipstick must be working properly for the pink Control Line to appear. For the dipstick to be working properly, the capillary flow must occur.
3. A clear background is an internal background negative control. If no interfering substances are in the specimen and the dipstick is working properly, the background in the Control Line area will remain clear. A discernible result will be seen.

If the pink Control Line does not appear, the test may be invalid. If the background does not clear and interferes with the test result, the test may be invalid. Call the Customer Support Line if either of these occur.

External Quality Control Testing

Each kit contains positive and negative control material. The controls are for external quality control testing. Use the controls to test that the extraction and the dipsticks are working. Also use the controls to test that you are able to correctly perform the procedure.

A positive and a negative control must be tested once with each 25 tests.

QC testing procedure

1. Dispense 4 drops of Reagent 1 and 4 drops of Reagent 2 into a test tube.
2. Vigorously mix the control contents. Add 1 free falling drop of control from the Positive control dropper vial into the test tube. Repeat with the Negative control into a different test tube.
3. Place a clean swab into the test tube.
4. Continue as you would for a patient sample (listed under patient test procedure).

3. Patient Test Procedure

1. Collect the patient sample as described above.
2. Just before testing, add 4 drops of Reagent 1 (pink) and 4 drops of Reagent 2. The solution should change to light yellow.
3. Immediately put the swab into the test tube.
4. Vigorously mix the solution by rotating the swab forcefully against the side of the tube at least ten (10) times. Best results are obtained when the specimen is vigorously extracted in the solution.
5. Let stand for 1 minute.
6. Express as much liquid as possible by squeezing the sides of the tube as the swab is removed.
7. Discard the swab.
8. Place the absorbent end of the dipstick into the sample (arrows pointing down).
9. Read results at 5 minutes. Positive results may be read as soon as the pink control line appears.

4. Reporting and interpreting results

• A pink test line and a pink control line are a positive result for the detection of Group A Streptococcus antigen. Note that the pink line may be any shade of color.
• A pink control line and no pink test line is a presumptive negative result.

Notes

• A pink line that appears uneven in color density is considered a valid result. In cases of moderate or high positive results, some red color behind the test line may be seen. As long as the test line and the control line are visible, the results are valid.
• If after 10 minutes, no pink control line appears or background color makes reading the red line impossible, the test is invalid. Repeat the testing on a new dipstick or contact the Customer Support Line.
• All results and internal QC results are to be recorded on the QC Log sheet and on the Patient Chart/EMR.