Diagnosing Streptococcal Pharyngitis

Abstract

<h3>To the Editor.</h3> —The article entitled "Insensitivity of Rapid Antigen Detection Methods and Single Blood Agar Plate Culture for Diagnosing Streptococcal Pharyngitis" by Wegner and colleagues,¹while attempting to assist clinicians in management of group A streptococcal infections, unfortunately reaches unjustified conclusions without taking a number of important factors into consideration. First and most important, it is very difficult to believe that experienced microbiologists can find group A streptococci on only 58% of the plates after 24 hours and on only approximately 70% of the plates after 2 days. Even if there is an accepted discordance rate (one positive and one negative) of about 10% when using two swabs as shown in reference 8 of the article, this still indicates that those who read the single plates missed about 20%. This is unacceptably high for a laboratory. The authors could have attempted to explain this unexpected finding by performing