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26281 Group A Strep Nucleic Acid Test

Group A Strep Nucleic Acid Test
Test Code: GASNAT
Synonyms/Keywords

​​GASNAT, Strep A, Streptococcal A, Streptococcus pyogenes, Group A Strep

Useful For

​This test is useful as a qualitative, diagnostic test for the detection of Streptococcus pyogenes (Group A Strep, Strep A) acute pharyngitis infections.  Definitive testing results are provided without the need for follow up culture.

Specimen Requirements
Specimen TypePreferred Container/TubeAcceptable Container/TubeSpecimen VolumeSpecimen Minimum Volume
(allows for 1 repeat)		Pediatric Minimum Volume
(no repeat)
​Throat Specimen​ESwab™-purple top ​​1 Swab​1 Swab​1 Swab
Collection Processing Instructions
  • Use the ESwab (purple top-480CFA) Collection and Transport System. Remove the swab from the wrapper.
  • Swab the posterior pharynx, tonsil, and other inflamed areas. Avoid touching the tongue, cheeks, and teeth with the swab when collecting specimens.
  • Uncap the ESwab transport tube.
  • Place the specimen containing swab into the ESwab transport tube and break the swab at the indicated score line.
  • Cap the ESwab transport tube.

Note: If patient is presenting at MMC-Marshfield Pediatrics department do not order this test.  Order Group A Strep by PCR, Point of Care (GASNATP)

 

If patient is presenting at a regional lab site that continues to perform rapid antigen testing and uses PCR from a central laboratory for confirmation of negative samples please collect two swabs by the following process: 

Remove a Puritan polyester swab from the rapid antigen kit and a flocked swab from the ESwab kit.  Simultaneously swab the throat with the two swabs.  Place the Puritan swab back in the wrapper for RAGT testing.  Place the flocked swab into the ESwab tube and break off the shaft at the red score point. If the RADT is negative, refer the ESwab for confirmatory testing by PCR.

Acceptable Body Sites

​Throat

Acceptable Specimen Types

​ESwab

Specimen Stability Information

Specimen Type

 ​

​
​ ESwab- purple Top ​TemperatureTime
15-30◦C​​48 hours
​2-8◦C​6 days

 

Rejection Criteria
Sources other than throat
Specimens exposed to excessive heat​
​Wooded shafted swabs
Calcium alginate swabs​
Cotton-tipped swabs​
Frozen swabs​
​Leaking specimens
Interference

​To reduce the potential for false negative results, do not collect throat swab specimens immediately after patients have used antiseptic mouthwash

Performing Laboratory Information
Performing LocationDay(s) Test PerformedAnalytical TimeMethodology/Instrumentation
​Beaver Dam
​​Monday through Sunday
​1 hour
​Nucleic Acid Test (PCR Based)
​Chetek
​Monday through Sunday
​1 hour​Nucleic Acid Test (PCR Based)
​Chippewa Falls​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Colby/Abbotsford​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Cumberland​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Eau Claire​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Greenwood​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Hayward​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
LadysmithMonday through Sunday1 hourNucleic Acid Test (PCR Based)
​Lake Hallie​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Marshfield Labs-Microbiology​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Marshfield Clinic-Pediatrics​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
MinocquaMonday through Sunday1 hourNucleic Acid Test (PCR Based)
​Menomonie​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Merrill​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Mosinee​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
NeillsvilleMonday through Sunday1 hourNucleic Acid Test (PCR Based)
​Oakwood​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Phillips​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Park Falls​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Rice Lake​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Stettin​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Stevens Point​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Wausau​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Weston​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Wisconsin Rapids​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
Test Information

​Additionally follow-up testing by culture is required if the Xpert Xpress Strep A test results is negative and clinical symptoms persist, or there is an outbreak of acute rheumatic fever.

'ESwab' is a trademark of Copan Diagnostics.

Reference Range Information
Performing LocationReference Range
​All Performing Sites​No Streptococcal A detected
Interpretation

​Positive, Negative, or Indeterminate ​

Outreach CPTs
CPTModifier
(if needed)		QuantityDescriptionComments
​87651​​​​
Synonyms/Keywords

​​GASNAT, Strep A, Streptococcal A, Streptococcus pyogenes, Group A Strep

Ordering Applications
Ordering ApplicationDescription
​Cerner​Group A Strep Nucleic Acid Test
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen TypePreferred Container/TubeAcceptable Container/TubeSpecimen VolumeSpecimen Minimum Volume
(allows for 1 repeat)		Pediatric Minimum Volume
(no repeat)
​Throat Specimen​ESwab™-purple top ​​1 Swab​1 Swab​1 Swab
Collection Processing
  • Use the ESwab (purple top-480CFA) Collection and Transport System. Remove the swab from the wrapper.
  • Swab the posterior pharynx, tonsil, and other inflamed areas. Avoid touching the tongue, cheeks, and teeth with the swab when collecting specimens.
  • Uncap the ESwab transport tube.
  • Place the specimen containing swab into the ESwab transport tube and break the swab at the indicated score line.
  • Cap the ESwab transport tube.

Note: If patient is presenting at MMC-Marshfield Pediatrics department do not order this test.  Order Group A Strep by PCR, Point of Care (GASNATP)

 

If patient is presenting at a regional lab site that continues to perform rapid antigen testing and uses PCR from a central laboratory for confirmation of negative samples please collect two swabs by the following process: 

Remove a Puritan polyester swab from the rapid antigen kit and a flocked swab from the ESwab kit.  Simultaneously swab the throat with the two swabs.  Place the Puritan swab back in the wrapper for RAGT testing.  Place the flocked swab into the ESwab tube and break off the shaft at the red score point. If the RADT is negative, refer the ESwab for confirmatory testing by PCR.

Acceptable Body Sites

​Throat

Acceptable Specimen Types

​ESwab

Specimen Stability Information

Specimen Type

 ​

​
​ ESwab- purple Top ​TemperatureTime
15-30◦C​​48 hours
​2-8◦C​6 days

 

Rejection Criteria
Sources other than throat
Specimens exposed to excessive heat​
​Wooded shafted swabs
Calcium alginate swabs​
Cotton-tipped swabs​
Frozen swabs​
​Leaking specimens
Interference

​To reduce the potential for false negative results, do not collect throat swab specimens immediately after patients have used antiseptic mouthwash

Useful For

​This test is useful as a qualitative, diagnostic test for the detection of Streptococcus pyogenes (Group A Strep, Strep A) acute pharyngitis infections.  Definitive testing results are provided without the need for follow up culture.

Reference Range Information
Performing LocationReference Range
​All Performing Sites​No Streptococcal A detected
Interpretation

​Positive, Negative, or Indeterminate ​

For more information visit:
Performing Laboratory Information
Performing LocationDay(s) Test PerformedAnalytical TimeMethodology/Instrumentation
​Beaver Dam
​​Monday through Sunday
​1 hour
​Nucleic Acid Test (PCR Based)
​Chetek
​Monday through Sunday
​1 hour​Nucleic Acid Test (PCR Based)
​Chippewa Falls​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Colby/Abbotsford​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Cumberland​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Eau Claire​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Greenwood​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Hayward​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
LadysmithMonday through Sunday1 hourNucleic Acid Test (PCR Based)
​Lake Hallie​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Marshfield Labs-Microbiology​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Marshfield Clinic-Pediatrics​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
MinocquaMonday through Sunday1 hourNucleic Acid Test (PCR Based)
​Menomonie​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Merrill​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Mosinee​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
NeillsvilleMonday through Sunday1 hourNucleic Acid Test (PCR Based)
​Oakwood​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Phillips​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Park Falls​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Rice Lake​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Stettin​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Stevens Point​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Wausau​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Weston​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
​Wisconsin Rapids​Monday through Sunday​1 hour​Nucleic Acid Test (PCR Based)
For billing questions, see Contacts
Outreach CPTs
CPTModifier
(if needed)		QuantityDescriptionComments
​87651​​​​
For most current information refer to the Marshfield Laboratory online reference manual.