[Reliability of the rapid Streptococcus A test].
The results of three second-generation immune assays for direct detection of group A streptococcus were compared in 65 patients with acute pharyngitis. The assays included Strep A Plus, (Abbott), Concise Strep A (Hybritech) and Cards Plus (Pacific Biotech). A standard culture was used as reference. Additionally a nucleic acid hybridization assay (Gen-Probe) was applied after enhanced broth culturing. The sensitivities and specificities of the three immunoassays were similar and showed that Strep A Plus had an 84.2% sensitivity and 88.9% specificity, Concise Strep A an 82.4% sensitivity and 92.3% specificity, and Cards Plus an 84.2% specificity and 90.7% sensitivity. The Concise Strep A had significantly more doubtful results in comparison with the two other rapid immune assays (9.7% versus 2.3%, P = 0.034. The standard culture and the DNA probe test gave the same results in 94% of cases. Clinical parameters were found to be unreliable for the diagnosis of group A streptococcal pharyngitis. However, findings show that when the rapid immune assay is positive, it is reasonable to start antibiotic treatment without performing a bacterial culture. In cases with a negative assay, management is best tailored to clinical symptoms and laboratory examinations.
Schmuziger
N
N
Universitäts-HNO-Klinik, Kantonsspital Basel.
Frei
R
R
Hauser
R
R
aWengen
D
D
Probst
R
R
D000293:Adolescent; D000328:Adult; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D001426:Bacterial Proteins; D001431:Bacteriological Techniques; D002648:Child; D015342:DNA Probes; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008297:Male; D008562:Membrane Glycoproteins; D008875:Middle Aged; D009693:Nucleic Acid Hybridization; D010612:Pharyngitis / Q000175:diagnosis* / Q000276:immunology; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000276:immunology; D013297:Streptococcus pyogenes / Q000276:immunology; D014069:Tonsillitis / Q000175:diagnosis* / Q000276:immunology
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D015342:DNA Probes; D008562:Membrane Glycoproteins; C055764:S-layer proteins