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POCT Streptococcus Group A Antigen
|Performed by||Authorized Point of Care testing site staff|
|In House Availability||During clinic hours|
|Method||Two-site sandwich EIA (Signify Strep A)|
|Collection Instructions||Use sterile polyester swab to collect sample.
Note: in order to provide a samples for culture should it be needed it is recommended that two swabs be collected. The sample for culture should be submitted in charcoal transport media to maintain viability on non-streptococcal organisms that may also cause pharyngitis.
|Sample type||Swab of posterior nasopharynx|
|Synonyms||Beta-hemolytic Strep; beta-strep|
|Additional information||Note that regulations require that all negative rapid tests be follow-up by culture to avoid false negatives.
The accuracy of the test depends on the quality of the swab sample. False negatives may result from improper sample collection or storage. A negative result may be obtained from patient at the onset of the disease due to low antigen concentration.
The test does not differentiate asymptomatic carriers of Group A Streptococcus from those with infection. If clinical signs and symptoms are not consistent with laboratory test results, a follow up throat culture is recommended.
Respiratory infections, including pharyngitis, can be caused by streptococci from serogroups other than group A, as well as other pathogens.
In rare cases, test specimens that are heavily colonized by Staphylococcus aureus may show a very thin sharp line in the test region. This line is unlike the thick line seen with the positive control and other Group A streptococcal strains. If clinical signs and symptoms are not consistent with clinical test result, a follow-up culture should be performed.
It is not known how the device (test) will perform in the presence of Fusobacterium necrophorum.
A definitive clinical diagnosis should not be based on the results of a single test, but should only be made by a physician after all clinical and laboratory findings have been evaluated
|LDT or Mod FDA?||No|
|Last Updated||5/22/2013 1:56:26 PM|