Group A Streptococcal (GAS) Infections Questions & Answers

Updated: Aug 08, 2017
  • Author: Zartash Zafar Khan, MD, FACP; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
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Questions & Answers

Overview

What is group A Streptococcus (GAS)?

Which disorders are caused by group A streptococcal (GAS) infection?

How many serologic groups have been identified for beta-hemolytic streptococci (BHS)?

What is the role of emm typing for the classification of group A streptococci (GAS)?

What distinguishes group A streptococci (GAS) from other serologic groups?

What is the basis for presumptive identification of a strain as a group A Streptococcus (GAS)?

How has morbidity of group A streptococci (GAS) infection changed since the widespread use of antibiotics?

Which disorders are included in the suppurative spectrum of group A streptococci (GAS) diseases?

What are the nonsuppurative sequelae of group A streptococci (GAS) infections?

How do group A streptococcal (GAS) infections cause scarlet fever and toxic shock syndrome (TSS)?

What is group A streptococci (GAS)?

What is the pathophysiology of group A streptococcal (GAS) infection?

What is the clinical implication of the ability of group A streptococci (GAS) to invade epithelial cells?

Which cell wall antigens are found in group A streptococcal (GAS) infection?

What is the polysaccharide (C-substance) composed of and what is its role in the pathogenesis of group A streptococcal (GAS) infections?

What is the role of C5A peptidase and M protein in the pathogenesis of group A streptococcal (GAS) infections?

What allows the survival of group A streptococci (GAS) and initiation of the disease process?

What is the role of M protein serotyping in epidemiologic studies of group A streptococcal (GAS) infections?

What is the role of surface components of group A streptococci (GAS) in adhesion?

What is the 2-step model of adhesion in group A streptococcal (GAS) infection?

What drives the evolving molecular activity of group A streptococci (GAS)?

What causes host cell damage and inflammatory response in group A streptococcal (GAS) infections?

What role do hemolysins have in group A streptococcal (GAS) infections?

What role do streptococcal pyrogenic exotoxins (SPEs) have in group A streptococcal (GAS) infections?

What role do nucleases have in group A streptococcal (GAS) infections?

Which extracellular products may have a role in group A streptococcal (GAS) infections?

How often is acute pharyngitis caused by group A streptococci (GAS)?

What is pyoderma (impetigo contagiosa) (nonbullous impetigo), and what are its risk factors as a manifestation of group A streptococcal (GAS) infection?

How is pyoderma (impetigo contagiosa) (nonbullous impetigo) transmitted in group A streptococcal (GAS) infections?

What is the pathogenesis of pyoderma (impetigo contagiosa) (nonbullous impetigo) in group A streptococcal (GAS) infections?

Does group A Streptococcus (GAS) cause pneumonia?

What is the pathogenesis of necrotizing fasciitis in group A streptococcal (GAS) infection?

What are possible suppurative complications of tonsillopharyngitis caused by group A streptococci (GAS)?

What are the symptoms of acute rheumatic fever (ARF) following group A streptococcal (GAS) tonsillopharyngitis?

Does rheumatic fever (ARF) have a genetic predisposition?

What is the link between group A streptococcal (GAS) infections of the upper respiratory tract and acute rheumatic fever (ARF)?

What is the attack rate of acute rheumatic fever (ARF) following respiratory tract group A streptococcal (GAS) infections?

What is the pathogenesis of acute rheumatic fever (ARF) in group A streptococcal (GAS) infections?

Is there a link between a host's autoimmune response to group A streptococci (GAS) and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS)?

Does group A streptococcal (GAS) infection cause glomerulonephritis?

What is the pathogenesis of poststreptococcal glomerulonephritis (PSGN) in group A streptococcal (GAS) infection?

Does group A streptococcal (GAS) infection cause toxic shock syndrome (TSS)?

What is the pathogenesis of toxic shock syndrome (TSS) in patients with group A streptococcal (GAS) infections?

What is the pathogenesis of scarlet fever in patients with group A streptococcal (GAS) infection?

How often does scarlet fever occur in patients with group A streptococcal (GAS) infections?

Does group A streptococcal (GAS) infection cause central nervous system (CNS) disease?

Who is at risk for infection by group A streptococci (GAS)?

How is group A Streptococcus (GAS) transmitted?

What is the major route for transmission of group A streptococci (GAS)?

How do children with untreated acute infections spread group A streptococci (GAS)?

Can asymptomatic carriers transmit group A Streptococcus (GAS)?

Which body surfaces can harbor group A streptococci (GAS), potentially helping to disseminate impetigo?

Which environmental factors increase the risk of group A streptococcal (GAS) impetigo and pharyngitis?

What is the incidence of group A streptococcal (GAS) infections in the US?

Are there regional differences in the incidence of skin and upper respiratory tract group A streptococcal (GAS) infections in the US?

What factors are responsible for the emergence of more virulent strains of group A streptococci (GAS)?

What is the prevalence of acute rheumatic fever (ARF) in the US?

When was a global resurgence of group A streptococcal (GAS) infections seen?

What is the incidence of rheumatic fever in Denmark?

What is the international incidence of poststreptococcal glomerulonephritis (PSGN)?

What is the global incidence of group A streptococcal (GAS) infections?

Where is the prevalence of streptococcal pyoderma (impetigo contagiosa) (nonbullous impetigo) highest?

Does group A streptococcal (GAS) infection have a sex or racial predilection?

What are the age-related differences in the prevalence of group A streptococcal (GAS) infections?

What age group is most at risk for acute rheumatic fever (ARF) following group A streptococcal (GAS) upper respiratory tract infection?

What is the prognosis of acute proliferative poststreptococcal glomerulonephritis (PSGN) and group A streptococcal (GAS) pharyngitis and skin infections?

What are the mortality rates of invasive group A streptococcal (GAS) infections, streptococcal toxic shock syndrome (TSS), and necrotizing fasciitis?

How do suppurative complications occur in group A streptococcal (GAS) infections?

Is acute hematogenous osteomyelitis a possible complication of group A streptococcal (GAS) infections?

What are the possible complications of group A streptococcal (GAS) toxic shock syndrome (TSS) and necrotizing fasciitis?

What are the possible complications of group A streptococci (GAS) that colonize the genital tract and enter the bloodstream during pregnancy and childbirth?

How common is empyema in patients with group A streptococcal (GAS) pneumonia?

What are the possible nonsuppurative complications of group A streptococcal (GAS) tonsillopharyngitis?

What patient education resources are available for group A streptococcal (GAS) infections?

Presentation

What are the signs and symptoms of group A streptococcal (GAS) erysipelas?

Which diseases are caused by group A streptococcal (GAS) infection?

What are the symptoms of strep throat?

Which symptoms are exclusionary in the diagnosis of streptococcal pharyngitis (strep throat)?

What are the symptoms of streptococcal pharyngitis (strep throat) in infants and toddlers?

What are the less common symptoms of streptococcal pharyngitis (strep throat) in children?

What is the etiology of scarlet fever in patients with group A streptococcal (GAS) infections?

What are the signs and symptoms of group A streptococcal (GAS) cellulitis?

What is the presentation of group A streptococcal (GAS) impetigo (impetigo contagiosa) (nonbullous impetigo)?

How does group A streptococcal (GAS) infection cause necrotizing fasciitis (streptococcal gangrene/fasciitis)?

What are the signs and symptoms of group A streptococcal (GAS) necrotizing fasciitis (streptococcal gangrene/fasciitis)?

What is a major risk factor for the development of group A streptococcal (GAS) necrotizing fasciitis (streptococcal gangrene/fasciitis)?

Do the risk factors for group A streptococcal (GAS) bacteremia vary by age?

What are the signs and symptoms of group A streptococcal (GAS) toxic shock syndrome (STSS)?

What are the Jones criteria for diagnosis of acute rheumatic fever (ARF)?

When do the first symptoms of acute rheumatic fever (ARF) appear, and when is rheumatic heart disease likely to occur?

What are the signs and symptoms of poststreptococcal glomerulonephritis (PSGN)?

When does scarlet fever rash typically appear in patients with group A streptococcal (GAS) infections and how is it identified?

What are physical findings of streptococcal pharyngitis (strep throat)?

What are the physical exam findings of scarlet fever, and how does the rash develop?

Which physical findings differentiate streptococcal pharyngitis (strep throat) from pharyngitis of other etiologies?

Which physical findings suggest streptococcal pharyngitis (strep throat)?

Can a diagnosis of streptococcal pharyngitis (strep throat) be made clinically?

What is Strep-PRO and is it effective as an outcome measure for streptococcal pharyngitis (strep throat)?

What is the typical disease course of with group A streptococcal (GAS) impetigo (impetigo contagiosa) (nonbullous impetigo)?

What happens if group A streptococcal (GAS) impetigo (impetigo contagiosa) (nonbullous impetigo) is left untreated?

What are the possible complications of group A streptococcal (GAS) impetigo (impetigo contagiosa) (nonbullous impetigo)?

What are the signs and symptoms of streptococcal cellulitis?

When should perianal cellulitis and vaginitis be considered in children with group A streptococcal (GAS) infections?

How is erysipelas differentiated from cellulitis in patients with group A streptococcal (GAS) infections?

What test should be performed when erysipelas or cellulitis is suspected in patients with group A streptococcal (GAS) infections?

What respiratory findings suggest group A streptococcal (GAS) infection?

How is necrotizing fasciitis (streptococcal gangrene/fasciitis) differentiated from cellulitis in group A streptococcal (GAS) infections?

What is the disease course of group A streptococcal (GAS) necrotizing fasciitis (streptococcal gangrene/fasciitis)?

Which disorders should be included in the differential diagnoses of scarlet fever?

Which symptoms suggest poststreptococcal glomerulonephritis (PSGN)?

What are the signs of sepsis in patients with group A streptococcal (GAS) infections?

What are the diagnostic criteria for streptococcal toxic shock syndrome (STSS)?

DDX

Which disorders should be included in the differential diagnoses of group A streptococcal (GAS) infection?

Workup

Which tests may be used in the workup of group A streptococcal (GAS) infection?

Which ancillary lab tests may be useful in the diagnosis and management of group A streptococcal (GAS) infections?

What is the criterion standard diagnostic test for streptococcal pharyngitis (strep throat)?

Which culture techniques are used to identify group A streptococcal (GAS) infections?

Which studies should be performed in the diagnosis of systemic group A streptococcal (GAS) infections?

How is a diagnosis of poststreptococcal glomerulonephritis (PSGN) confirmed?

Is posttreatment throat culture necessary in asymptomatic patients with group A streptococcal (GAS) infections or asymptomatic family contacts?

When are rapid antigen detection tests used to confirm a diagnosis of streptococcal pharyngitis (strep throat)?

Which indicator systems are used to detect group A carbohydrate antigens in the workup of group A streptococcal (GAS) infections?

What is the sensitivity and specificity of rapid strep tests for the diagnosis of group A streptococcal (GAS) infections?

Do clinicians agree on the approach to diagnose and manage suspected streptococcal pharyngitis (strep throat)?

When are decisions made regarding lab testing for diagnosis of group A streptococcal (GAS) infections?

Are there effective clinical scoring systems for predicting the results of subsequent lab tests for group A streptococcal (GAS) infections?

What risks are associated with treating children based on a clinical diagnosis of streptococcal pharyngitis (strep throat)?

Are antigen detection systems as valid as throat culture for the diagnosis of streptococcal pharyngitis (strep throat)?

What is the sensitivity of a throat culture for the presence of group A streptococcal (GAS) infections?

Does a negative throat culture result rule out a diagnosis of streptococcal pharyngitis (strep throat)?

When is throat culture for group A streptococcal (GAS) infection contraindicated?

What testing is required for a diagnosis of acute rheumatic fever (ARF)?

Is throat culture or group A streptococcal (GAS) antibody testing preferred during workup of acute rheumatic fever (ARF)?

What is the most commonly used group A streptococcal (GAS) antibody test for acute rheumatic fever (ARF)?

What is the role of imaging studies in the workup of group A streptococcal (GAS) infection?

Which imaging studies are helpful in the diagnosis of central nervous system (CNS) manifestations of group A streptococcal (GAS) infections?

Which histologic findings suggest group A streptococcal (GAS) infection?

Treatment

Which complications should a physician be aware of in patients with group A streptococcal (GAS) infection?

Which procedures may be necessary for the management of group A streptococcal (GAS) infections?

What is the treatment for shock in patients with group A streptococcal (GAS) infection?

When is tonsillectomy indicated in children with streptococcal pharyngitis (strep throat)?

Which patients with group A streptococcal (GAS) infection should be hospitalized?

How is necrotizing fasciitis (streptococcal gangrene/fasciitis) managed?

When is rehabilitative care necessary in the treatment of group A streptococcal (GAS) infections?

What is the goal of therapy for streptococcal pharyngitis (strep throat)?

Does a delay in antibiotic therapy for streptococcal pharyngitis (strep throat) affect treatment efficacy?

Which treatments are effective in patients with streptococcal pharyngitis (strep throat) who are allergic to penicillin?

Is cephalosporin effective for the treatment of group A streptococcal (GAS) tonsillopharyngitis?

How is streptococcal pharyngitis (strep throat) managed if treatment fails and symptoms recur?

What is the most common reason for antibiotic failure in streptococcal pharyngitis (strep throat)?

What are the possible causes of penicillin treatment failure in streptococcal pharyngitis (strep throat)?

What is the rate of group A streptococci (GAS) macrolide resistance?

What is the treatment for group A streptococcal (GAS) pyoderma (impetigo contagiosa) (nonbullous impetigo)?

What is the role of polyspecific IVIG in the treatment of streptococcal toxic shock syndrome (STSS)?

What is the treatment for group A streptococcal (GAS) necrotizing fasciitis (streptococcal gangrene/fasciitis?

Which factors increase the risk of penicillin therapy failure in the treatment of group A streptococcal (GAS) infections?

What is the role of clindamycin in the treatment of group A streptococcal (GAS) infections?

Is posttreatment throat culture indicated in the treatment of group A streptococcal (GAS) infections?

How likely are asymptomatic carriers to transmit group A streptococci (GAS) to close contacts?

When are follow-up throat cultures indicated in group A streptococcal (GAS) infections?

When is long-term antibiotic therapy indicated for prevention of group A streptococcal (GAS) infections?

What is the role of prophylaxis for household contacts of patients with group A streptococcal (GAS) infections?

What information should be given to close contacts of a patient with invasive group A streptococcal (GAS) infection?

What is the approach to prophylaxis to eradicate household transmission of group A streptococcal (GAS) infections?

How are group A streptococcal (GAS) infections prevented?

Which specialists may be consulted in the treatment of group A streptococcal (GAS) infections?

Guidelines

What are the IDSA guidelines for the diagnosis of group A streptococcal (GAS) infections?

What are the IDSA guidelines for the treatment of group A streptococcal (GAS) infections?

Medications

What is the first-line drug of choice for treatment of group A streptococcal (GAS) infections?

Do group A streptococcal (GAS) isolates exhibit resistance to macrolides?

Are group A streptococcal (GAS) isolates susceptible to levofloxacin?

Are group A streptococcal (GAS) strains susceptible to 8 beta-lactam agents?

What is the rate of antibiotic resistance among group A streptococcal (GAS) isolates?

Which medications in the drug class Antibiotics are used in the treatment of Group A Streptococcal (GAS) Infections?