The incidence of streptococcal illness is known to decrease markedly with adulthood (Schwentker et al 11).Presumably one factor in this decrease is the development of active immunity during childhood. More than 35 types of group A hemolytic streptococci have been identified (Swift et al 13), and the careful work of Quinn and Lowry 9 indicates that some of the nontypable strains may also have antigenic M-protein. Yet the average person does not suffer 35 or more seperate episodes of steptococcal illness, and it would seem possible that inapparent infection might play some part in the acquisition of the normal immunity of maturity.
The relationship between the carrier state and disease has not been fully explored. The extensive work of Cornfeld and Hubbard,1 James et al,4 Kincaid et al,5 Nicholas and Steele,7 Saslow and Streitfeld,10 Siegel et al,12 Wannamaker et al,14 and many