Product Manual

Page 7 of 66QuickVue+ Strep A test
FOR INFORMATIONAL USE ONLY
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FOR INFORMATIONAL USE ONLY
Not to be used for performing assay. Refer to most current package insert accompanying your test kit.
LIMITATIONS OF THE PROCEDURE
The contents of this kit are for use in the qualitative detection of Group A Streptococcal
antigen from throat swabs and culture colonies only.
Respiratory infections, including pharyngitis, can be caused by Streptococcus from
serogroups other than Group A as well as other pathogens. The QuickVue+ test will
not differentiate asymptomatic carriers of Group A Streptococcus from those exhibiting
Group A Streptococcal infection.
In rare cases, test specimens heavily colonized with Staphylococcus aureus can yield
false positive results.
Test results must always be evaluated with other data available to the physician. A
negative test result might occur if the level of extracted antigen in a sample is below
the detection level of the test. Additional follow-up testing using the culture method
is recommended if the QuickVue+ test result is negative.
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EXPECTED VALUES
Group A Streptococci cause about 19% of all upper respiratory tract infections.
Streptococcal pharyngitis is seasonal in nature with the highest prevalence found during
the winter and early spring. The highest incidence of this disease is found in crowded
populations such as military bases and in school-aged children, and is evenly distributed
between males and females.
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PERFORMANCE CHARACTERISTICS
Clinical Sensitivity and Specificity
A multi-center evaluation of the QuickVue+ Strep A test was conducted to determine
the clinical performance of the test relative to standard sheep blood agar (SBA) culture
techniques. Throat swab specimens were collected from patients presenting with
pharyngitis. Prior to performance of the QuickVue+ test, each swab specimen was
inoculated onto a SBA culture plate containing a bacitracin disk and incubated at
37°C anaerobically for 24–48 hours for evaluation. All cultures were confirmed for the
presence of Group A Streptococcus using commercial latex agglutination assays.
Of the 719 specimens that were found negative by SBA culture, 707 were also negative
by the QuickVue+ test. Similarly, of the 114 specimens that were confirmed SBA culture
positive, 108 were also positive by the QuickVue+ test. The QuickVue+ test correctly
identified 100% (5/5) of the 1+ cultures; 95% (20/21) of the 2+ cultures; 100% (31/31) of
the 3+ cultures; and 98% (52/53) of the 4+ cultures. The 4 culture positive specimens
with less than 10 colonies (rares) were not positive by the QuickVue+ test. Based on