Group A streptococci are model extracellular gram-positive pathogens responsible for pharyngitis, impetigo, rheumatic fever, and acute glomerulonephritis. A resurgence of invasive streptococcal diseases and rheumatic fever has appeared in outbreaks over the past 10 years, with a predominant M1 serotype as well as others identified with the outbreaks. emm (M protein) gene sequencing has changed serotyping, and new virulence genes and new virulence regulatory networks have been defined. The emm gene superfamily has expanded to include antiphagocytic molecules and immunoglobulin-binding proteins with common structural features. At least nine superantigens have been characterized, all of which may contribute to toxic streptococcal syndrome. An emerging theme is the dichotomy between skin and throat strains in their epidemiology and genetic makeup. Eleven adhesins have been reported, and surface plasmin-binding proteins have been defined. The strong resistance of the group A streptococcus to phagocytosis is related to factor H and fibrinogen binding by M protein and to disarming complement component C5a by the C5a peptidase. Molecular mimicry appears to play a role in autoimmune mechanisms involved in rheumatic fever, while nephritis strain-associated proteins may lead to immune-mediated acute glomerulonephritis. Vaccine strategies have focused on recombinant M protein and C5a peptidase vaccines, and mucosal vaccine delivery systems are under investigation.

Pathogenesis of Group A Streptococcal Infections

Most research directed a t understanding ”activity undertaken by those who consider themselves ill, for the purpose of getting well” has yielded an unsystematic multiplicity of findings which are often either not predictive of such patient compliance,’” or are mutually contradictory.7.8 These difficulties arise, in part, from past dependence on a “medical” model of patient behavior, which stresses such easily identified and quantified dimensions as characteristics of the patient (e.g., demographic and social),6~B~lO the regimen (e.g., type, complexity, discomfort, duration),ll-l3 and the illness (e.g., medically-defined seriousness, duration, disability).7,14J5

The Health Belief Model and Sick Role Behavior

Epidemiology and Estimated Population Burden of Selected Autoimmune Diseases in the United States

There is concern that group A streptococci, which have caused less serious infections in developed countries in recent decades, may be acquiring greater virulence. We describe 20 patients from the Rocky Mountain region who had group A streptococcal infections from 1986 to 1988 that were remarkable for the severity of local tissue destruction and life-threatening systemic toxicity. Among the 20 patients (median age, 36), necrotizing fasciitis with or without myositis was the most common soft-tissue infection (55 percent). Nineteen patients (95 percent) had shock, 16 (80 percent) had renal impairment, and 11 (55 percent) had acute respiratory distress syndrome. The mortality rate was 30 percent. All patients but 1 had positive tissue cultures for Streptococcus pyogenes; 12 had positive blood cultures. Most of the patients had no underlying disease; 2 used intravenous drugs. Strains of group A beta-hemolytic streptococci isolated from 10 patients were not of a single M or T type; however, 8 of the 10 strains produced pyrogenic exotoxin A (scarlet fever toxin A, a classic erythrogenic toxin), which has rarely been observed in recent years. From our study of this cluster of severe streptococcal infections with a toxic shock-like syndrome, we conclude that in our region, more virulent group A streptococci have reappeared that produce the pyrogenic toxin A associated with scarlet fever.

Severe group A streptococcal infections associated with a toxic shock-like syndrome and scarlet fever toxin A

The guideline is intended for use by healthcare providers who care for adult and pediatric patients with group A streptococcal pharyngitis. The guideline updates the 2002 Infectious Diseases Society of America guideline and discusses diagnosis and management, and recommendations are provided regarding antibiotic choices and dosing. Penicillin or amoxicillin remain the treatments of choice, and recommendations are made for the penicillin-allergic patient, which now include clindamycin.

/pdf/clinical-practice-guideline-for-the-diagnosis-and-management-51g80uc39j.pdf

Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the Infectious Diseases Society of America.

Rheumatic Fever

Streptococcal pharyngitis: the case for penicillin therapy.

Two controlled studies were undertaken to evaluate the effectiveness of comprehensive and continuous pediatric care. In the first study, 220 infants of primiparous adolescents were randomly allocated to either a comprehensive care (CC) or traditional care (TC) group. CC infants received all medical care, preventive and therapeutic, in a hospital-based program staffed by a pediatrician, public health nurse, and social worker. Mothers of TC infants were left to obtain care from emergency rooms, well-baby and outpatient clinics. One year after delivery, each mother was interviewed and her infant9s medical records abstracted. No differences were found between CC and TC infants in completeness of immunization, utilization of medical resources, morbidity, or mortality. In a second study, it was hypothesized that patient compliance with physicians9 recommendations would be favorably influenced by continuous care. Seventy-seven children on daily oral penicillin prophylaxis for history of rheumatic fever (RF) were studied. For one year, compliance was determined by periodic urine tests for penicillin. Patients were then stratified for age, sex, and compliance and randomly allocated to continuous care (CC) or traditional care (TC) groups. CC patients received all medical care, even for problems unrelated to RF, from the same two physicians for 15 months. TC patients continued to receive specialty clinic care, were seen at the RF clinic by different physicians and referred elsewhere for all problems unrelated to RF. Urine specimens were tested periodically for penicillin. After 15 months, no differences were observed between CC and TC groups in proportion of noncompliers or in internal shifts in compliance which had occurred during the study. Thus, neither of these studies was able to demonstrate that comprehensive and continuous care was more effective than conventional ambulatory care for children.

Evaluation of the effectiveness of comprehensive and continuous pediatric care.

Rheumatic heart disease is considered one of the few forms of chronic heart disease which can be effectively prevented today. Yet the incidence of rheumatic fever is still appreciable and the complacency of many physicians and public health officials in regard to the rheumatic fever problem is unwarranted. It is timely, therefore, to reexamine the question of whether this disease can indeed be eradicated by presently available methods. One of the major factors limiting the prevention of initial attacks with antibiotics is that about two thirds of the patients who develop rheumaic fever do so following either asymptomatic or mild streptococcal infections. Furthermore, the low socioeconomic group, in whom the risk of rheumatic fever is the greatest, is the least likely to receive adequate care even for overt respiratory infections. Although the number of recurrent attacks has been reduced, approximately 10% of rheumatic patients still develop recurrences either because they are not on prophylaxis at all or ...

Milton Markowitz

Papers

Rheumatic Fever

Streptococcal pharyngitis: the case for penicillin therapy.

Evaluation of the effectiveness of comprehensive and continuous pediatric care.

Eradication of Rheumatic Fever An Unfulfilled Hope

The fall and rise of rheumatic fever in the United States: a commentary.