Comparison of the Alere i Strep A test and the BD veritor system in the detection of group a streptococcus and the hypothetical impact of results on antibiotic utilization

Rapid detection of group A Streptococcus (GAS) is an integral component of treatment decisions in the clinic, especially in the pediatric population. We prospectively collected 216 specimens from symptomatic, predominantly pediatric patients and evaluated the performance of the Alere i Strep A test (Alere i; Alere Inc., Scarborough, ME) and the BD Veritor system (BD Veritor; Becton, Dickinson and Company, Sparks, MD), with culture results being used as a comparator. Real-time PCR (RT-PCR) was performed as an arbiter in discordant cases. Comprehensive chart review was also done to determine the hypothetical impact of the results on antibiotic use. Alere i had a sensitivity and a specificity of 100% and 91.3%, respectively, and BD Veritor had a sensitivity and a specificity of 76.2% and 93.6%, respectively, when the results were compared to those of GAS culture. Further analysis of discordant results using RT-PCR revealed that while BD Veritor missed 13 confirmed positive cases, Alere i detected 100% (n 13) of the same cases. Analysis of assay agreement showed that Alere i and BD Veritor had only moderate agreement (agreement 0.888 [95% confidence interval {CI}, 0.838 to 0.927]; kappa index 0.689 [95% CI, 0.91 to 0.974]). We also found both the underutilization and the over-utilization of antibiotics based on the results of molecular testing. Overall, Alere i showed superior performance over BD Veritor in the detection of GAS pharyngitis and could potentially assist in better antibiotic utilization.