Molecular Point-of-Care Tests Challenge Culture-Based Strep A Diagnosis in Pediatrics

Original abstract

Each year, there are an estimated 11 million visits to ambulatory care centers for pharyngitis in children between the ages of 3 and 18 years. While there are many causes of pediatric pharyngitis, group A streptococcal pharyngitis represents 15 to 30% of infections and is the only cause for which treatment is recommended. Unfortunately, clinical suspicion is insufficient for the accurate diagnosis of group A streptococcal pharyngitis, and laboratory testing for confirmation of Streptococcus pyogenes infection is required to prevent complications of infection. Traditionally, throat swabs are inoculated onto agar plates for isolation of the large-zone beta-hemolytic streptococcus. However, traditional culture methods present a potential delay in treatment due to turnaround times of 18 to 48 h. In order to improve turnaround times and enhance antimicrobial stewardship, multiple point-of-care assays have been developed. This review describes current point-of-care testing for group A streptococcal pharyngitis, including rapid antigen detection tests and more recent molecular methods. Additional attention is given to the diagnostic considerations when choosing a method for group A streptococcal point-of-care testing, implementation of molecular group A streptococcal testing, and the institutional cost of immunoassays compared to those of newer molecular methods.