Rapid Strep Test Characteristics for Group A Beta-Hemolytic Streptococcal Infections

Key Test Characteristics

RADTs have excellent specificity of ≥95% compared with blood agar plate cultures, meaning false-positive results are rare and treatment decisions can be made confidently based on positive results 1, 2
Sensitivity of most RADTs ranges between 80-90% compared to throat culture, necessitating confirmation of negative results 1, 2

First-generation RADTs used latex agglutination methodology with relatively low sensitivity and unclear endpoints 1
Newer tests based on enzyme immunoassay (EIA) techniques offer more sharply defined endpoints and increased sensitivity 1, 2
Most recent RADTs using optical immunoassay and chemiluminescent DNA probes may approach the sensitivity of standard throat cultures 2

RADTs provide results much faster than throat cultures, allowing for more rapid treatment decisions 1
Rapid identification and treatment can reduce the spread of Group A streptococci and decrease acute morbidity 1, 2
A positive RADT result can be trusted and does not require culture confirmation due to high specificity 2, 3
A negative RADT result should be confirmed with conventional blood agar plate culture due to the possibility of false negatives 1, 2

Relying solely on RADT without culture confirmation of negative results, especially in high-risk populations 1, 2
Confusing strep antibody tests with RADTs 3