Article Text

SENSITIVITY AND SPECIFICITY OF A RAPID STREPTOCOCCAL TEST IN DIAGNOSIS OF STREPTOCOCCAL PHARYNGITIS AMONG CHILDREN IN AN OUTPATIENT SETTING
  1. A Nitsch-Osuch1,
  2. E Gyrczuk1,
  3. K Wardyn1
  1. 1Department of Family Medicine, Medical University of Warsaw, Warsaw, Poland

Abstract

Beta-hemolytic group A streptococcus is the most common bacterial agent associated with pharyngitis. Rapid antigen detection tests should be used to diagnose pharyngitis (tonsillitis) due to Streptococcus pyogenes infection in order to make a sure diagnosis and to reduce usage of antibiotics.

Material and Methods A prospective study was conducted among 116 children (70 girls, 46 boys) aged 2–14 years (mean age 5.9 years, SD 2.6 years). Inclusive criteria to the study were: fever >38°C and sore throat. None of the children received antibiotics prior to testing. In all children, a rapid streptococcal test (Test Strep A®, SureScreen, UK) and conventional culture from the pharyngeal swabs were performed.

Results The rapid streptococcal test was positive in 16 patients (13.7%) while culture was positive in 14 (12%) patients. Among all positive rapid strep tests there were 12 true positive and 4 false positive. Among negative rapid strep tests 98 were true negative and 2 false negative.

The sensitivity of a rapid strep test was estimated as 86% and specifity as 96%.

The sensitivity (86%) was lower than shown in a product monograph (97%, 95% CI 91% to 99%) while the specifity (96%) was comparable with data shown in a description provide by producer (95%, 95% CI 92% to 97%).

Conclusions The examined rapid strep test (Test Strep A®) was less sensitive than it was suggested in the product monograph, but the sensitivity of 86% and specifity of 96% reached in ambulatory conditions are still high enough to find this test useful for clinical usage.

Statistics from Altmetric.com

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.