Dr Soman's commentary on my editorial is appreciated. He raises a commonly recurrent question: should we stop use of penicillin, if once begun, if throat cultures for group A streptococci are negative? He cites three reports that show that infection is sometimes present and not detected by the throat culture techniques used. However, the clinician is left with an unsavory choice: should he continue using penicillin with no backup evidence for his clinical judgment, or should he discontinue its use, using the throat culture as an "absolute" gold standard? The answer is not easy. One balances the risk of unnecessarily prolonged exposure to penicillin (or an alternative antibiotic) against the risk of suppurative and/or nonsuppurative complications.
The question and its resolution will have even greater implications as physicians abandon throat cultures for the rapid latex agglutination methods now being increasingly employed throughout the United States. Does a physician decide not to treat with penicillin initially if the result of the rapid test is negative? From the available sensitivity and specificity data and the clinical positive and negative predictive values, it appears