The Relation of Upper Respiratory Infections

In the preceding article (1) evidence was presented which would not support the conception of a specific etiological relationship between respiratory infections and rheumatic fever in children. The designation, " streptococcal " respiratory infection, based solely on bacteriological findings, was questioned. During these observations as to the relation between respiratory infections and rheumatic fever, an opportunity presented itself for obtaining information as to the immunological response of children experiencing respiratory infection and rheumatic recurrences. The serological method described by Todd (2) in 1932 for titrating antistreptolysin in the blood serum, by which a diagnosis of preceding hemolytic streptococcal infection may be made, was utilized. From limited observations of normal individuals, mainly adults and others suffering from miscellaneous and streptococcal infections, Todd (3) and Coburn and Pauli (4) considered the normal range of antistreptolysin in serum to be from 5 to 100 units, and values of 200 or more as significant of preceding streptococcal infections. They also observed the antistreptolysin content to be consistently high during rheumatic fever and considered this as immunological evidence that the hemolytic streptococcus initiates the rheumatic process. Myers and Keefer (5), however, obtained an average in normals of 200 units, with a somewhat higher average, 500 units, in rheumatic fever, but they did not attribute etiological significance to this finding. Wilson, Wheeler and Leask (6), in a preliminary report on the antistreptolysin content of the