In Reply.— We share Dr Odio's concerns that evaluations of group A streptococcal antigen-detection kits should provide clinically relevant information and that comparisons of the new procedures be made using a welldocumented reference method, or the gold standard. As Dr Odio noted, a confirmed diagnosis of streptococcal pharyngitis requires a significant rise in antibody titer between acute and convalescent serum samples. Not being willing to wait the two to three weeks following onset of symptoms required for collection of convalescent serum samples, physicians have looked to the traditional culture and investigated the faster antigen-detection products as more practical alternatives. In the absence of a rapid serological test to confirm infection, the throat culture is merely a screen to determine the presence or absence of group A streptococci, and the rapid antigendetection kits serve the same purpose. Since the objectives of the two tests are identical, a competently performed throat culture