Rheumatic Fever in Children and Adolescents: A Long-term Epidemiologic Study of Subsequent Prophylaxis, Streptococcal Infections, and Clinical Sequelae: V. Relation of the Rheumatic Fever Recurrence Rate per Streptococcal Infection to Pre-existing Clinical Features of the Patients

Abstract

The attack rate of rheumatic fever after Group A streptococcal infections is higher in patients with previous rheumatic attacks than in the general population. In these patients, the possible relationship of some host factors to the outcome of streptococcal infections is uncertain, and has been analyzed in the present study. Over a 5-year period, 431 children and adolescents who had had rheumatic fever were examined monthly for 1,681 patient-years. Monthly throat cultures and at least bimonthly antibody determinations were done. Despite continuous antistreptococcal prophylaxis with either oral penicillin, oral sulfadiazine, or repository penicillin, 285 streptococcal infections occurred and were associated in 47 instances with definite rheumatic recurrences. Recurrences developed in 18 (10%) of 189 infections in patients with no heart disease, in 20 (27%) of 74 infections in patients with heart disease but no significant cardiomegaly, and in 9 (43%) of 21 infections in patients with heart disease and marked cardiomegaly. The relationship of the rheumatic fever recurrence rate per infection (R/I) to pre-existent heart disease was not due to spurious relationship of heart disease with antibody response or with age of the patient or with number of previous attacks of rheumatic fever. The R/T increased with the number of previous attacks of rheumatic fever; it was 11, 24, and 32% in patients with 1, 2, and 3 previous attacks, respectively. It decreased with time elapsed since the last attack of rheumatic fever, from 23% (6-23 months) to 11% (60+ months). The R/I was higher in children (19-21%) than in adolescents (14-13%). It bore no relationship to the occurrence of other streptococcal infections during 1, 2, or 3 years preceding the infections under consideration. These data indicate a relationship between the rheumatic fever recurrence rate per infection and certain underlying clinical features of the patients, that are independent of the streptococcal infections directly involved.