Current status of prophylaxis against rheumatic fever

Abstract

In the general population, rheumatic fever can be prevented by the prompt identification and adequate treatment of Group A streptococcal pharyngitis. The increased use of accurate throat cultures in all forms of respiratory illness will enable symptomatic streptococcal infections to be recognized when they are present and will avoid unnecessary antibiotic therapy when they are absent. Since about half of streptococcal infections are asypmtomatic, they will escape detection because the patient does not seek medical attention. In the best of circumstances, therefore, it would be impossible to reduce the rate of first attacks of rheumatic fever by more than 50 per cent. Once an attack has occurred and the individual patient's susceptibility is noted, the prevention of recurrences becomes particularly important. This involves the adequate treatment of streptococcal infections whenever they are found, but also demands prophylactic measures to cope with the hazards of unrecognized infections. The prophylaxis can be accomplished by giving daily doses of oral antimicrobial agents, monthly injections of a repository penicillin preparation, or monthly courses of an oral antibiotic at therapeutic dosage. At the present time, the most effective method of prophylaxis is a monthly injection of 1.2 million units of benzathine penicillin, because the maintenance of prophylaxis is assured and because the medication both eradicates streptococci and produces a persistent penicillin blood level thereafter. The general applicability of the injections is reduced by their potential for sensitization, particularly in adults, and the 10 per cent incidence of severely uncomfortable local reactions to them. Of the daily oral prophylactic methods, sulfadiazine, I Gm., appears to prevent rheumatic recurrences at least as well as 200,000 units of penicillin. It is now being compared against a larger dose of oral penicillin. Greater awareness of the comparative prophylactic effectiveness of sulfadiazine and the absence of any significant reactions to it, may be followed by its increased use as an oral prophylactic agent, either in preference to oral penicillin or as an alternative to it. The role of long-acting oral sulfamethoxypyridazine has not yet been established. If its one-dose-per-week convenience is matched by its prophylactic effectiveness, it may become a highly useful oral agent. Although the continuation of prophylaxis is now recommended for an indefinite period of time, more finite durations can be rationally established in many situations. The major factors which influence this choice will be the age of the patient, clinical status, and the remoteness from the previous rheumatic attack. Before continuous indefinite prophylaxis is undertaken in any patient, a concerted attempt should be made to verify the diagnosis of rheumatic fever or the existence of rheumatic heart disease.