Efficiency of Rapid Antigen Test in Diagnosis of Acute Streptococcal Tonsillopharyngitis

Abstract

Objective: Group A beta hemolytic streptococcus (GABHS) is the most common bacterial cause of acute tonsillopharyngitis. Cases with bacterial infection suspicion should undergo rapid antigen test (RAT) and/or throat culture test in addition to clinical criteria, since it may lead to serious complications.Method: A total of 220 adult and pediatric patients admitted to the emergency department between April-May 2016 with complaints of fever and sore throat, and diagnosed as acute tonsillopharyngitis were prospectively enrolled to the study. All participants had Centor score ≥2 and they underwent RAT. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of RAT results of both groups were compared. Throat culture was considered as gold standard method.Results: Mean age of the study population was 22,5±16,9 (1-72) years. 57% (n=61) of the pediatric group, and 42.5% (n=48) of adult group were male. Sensitivity of RAT in adults and pediatric group was 62% vs. 57%, and specificity of the test was 96% vs. 97%, PPV was 55% vs. 80%, and NPV was 97% vs. 93%, respectively.Conclusion: We found low sensitivity and PPV values of RAT. Also, low levels of sensitivity decrease the possibility of RAT to be a diagnostic tool for the diagnosis of GABHS.