Sensitivity Tests as a Means of Distinguishing Relapse from Re-Infection in the Treatment of Gonorrhoea

Abstract

According to the theory[long dash]or the probability[long dash]that a strain of gonococci, cannot change from resistance to sensitivity to penicillin, it may be supposed that the diagnosis of re-infection can sometimes be made by means of sensitivity tests. When the gonococci at the first examination are resistant (the inhibitory concentration of penicillin is 0.50 units/ml) and the gonococci at a re-examination 2 or 3 weeks later are very sensitive (to 0.03 units/ml), 2 different strains must be involved, indicating re-infection. The opposite case, high sensitivity (to 0.03 units/ml) followed by resistance (to 0.50 units/ml) 2 or 3 weeks later, also indicates re-infection.