Rheumatic Fever in Children and Adolescents: A Long-term Epidemiologic Study of Subsequent Prophylaxis, Streptococcal Infections, and Clinical Sequelae: IV. Relation of the Rheumatic Fever Recurrence Rate per Streptococcal Infection to the Titers of Streptococcal Antibodies

Abstract

Four hundred and thirty-one children and adolescents with previous attacks of rheumatic fever were examined monthly over a 5-year period, for 1,681 patient-years. Despite antistreptococcal prophylaxis, 285 streptococcal accompanied by significant antibody rises. The pre-infection antibody titers failed to show a consistent relationship to the rheumatic fever recurrence rate per infection. This rate increased with increasing magnitude of the antistreptolysin O (ASO) titer rises accompanying the infections: it was 15% in infections characterized by the minimal significant ASO rises and 70% in infections characterized by the maximal antibody rises observed. Similar, though less marked, increases were found with increasing antihyaluronidase and anti-streptokinase rises.