Does Your “Backup” Method Have Your Back? Controversies Surrounding Backup of Rapid Antigen Detection Methods for Group A Streptococcus

Accurate diagnosis of streptococcal pharyngitis followed by appropriate antibiotic therapy is important for the prevention and control of group A streptococcus (GAS) infection and its sequelae. Rapid antigen detection methods (RADTs) for detection of GAS antigen are commonly used to speed the diagnosis of streptococcal pharyngitis; however, reports of false-negative antigen tests are common. In this review, we describe the conflicting strategies that surround GAS testing and reflexive backup testing for samples found to be negative for Streptococcus pyogenes antigen. We invite you to examine your GAS backup or reflexive testing strategy and ask yourself, “Does my laboratory's GAS backup method have my back?” More importantly, “Is reflexive testing designed to provide optimized diagnostic care for my patient population?”