1924

George & Gladys Dick (Univ. Chicago) definitively link hemolytic streptococcus with scarlet fever and also show that the injection of filtrate (the erythrogenic toxin secreted by streptococcus in tonsils) produced round area of redness which resembled scarlet fever rash in those not exposed to the bacteria – the Dick test. In 1926, Francis Blake & James Trask (Yale) disproved the Dicks’ claim that the important features of scarlet fever were caused by the erythrogenic toxin rather than by the streptococcus per se (Dowling, 58-61).