You Say that You Want a Molecular Revolution? Changing from the Group A Streptococcus Antigen and Culture Paradigm to Molecular Testing

Abstract Group A Streptococcus (GAS) (Streptococcus pyogenes) is the most common bacterial cause of acute pharyngitis. Diagnosed cases of GAS pharyngitis should be treated with antibiotics to prevent primary and secondary complications. Commonly, testing for GAS pharyngitis can be done rapidly (in minutes) using rapid antigen detection tests (RADTs), which generally have relatively high specificity (>90%) but lower sensitivity (70 to 90%). The low sensitivity of GAS RADTs requires that culture be performed to maximize sensitivity, which delays the final result by 24 to 48 hours. New molecular GAS assays are on the market and offer relatively rapid (i.e., minutes to tens of minutes) and highly sensitive results so that culture is not required for negative results. We describe our experience with moving from RADT and culture testing for GAS to solely molecular testing, providing quicker results for improved patient care.