EFFECT OF SCARLET FEVER ON IMMUNITY TO DIPHTHERIA AS DETERMINED BY THE SCHICK TEST

The study reported on here, which extended over a period of four years, was concerned with observations on the effect of scarlet fever on immunity to diphtheria as determined by the Schick test in 219 hospitalized patients. The incentive to the study arose when one of us observed that clinical diphtheria developed in a patient who was convalescing from scarlet fever, although on admission the Schick reaction was reported to be negative. The question immediately presented itself as to whether this was due to faulty technic or to weak toxin or whether there might be a loss of immunity to diphtheria following an attack of scarlet fever. The possibility of weak toxin was quickly ruled out not only because fresh potent toxin is received at frequent intervals from the bureau of laboratories of the department of health but more so because other patients gave a positive Schick reaction at the