What is the recommended management for Group A Streptococcus (GAS) infections?

Management of Group A Streptococcus Infections

Penicillin remains the treatment of choice for Group A Streptococcus pharyngitis due to its proven efficacy, safety, narrow spectrum, and low cost, with oral penicillin V or amoxicillin for 10 days as first-line therapy. 1

First-Line Antibiotic Treatment

For Patients Without Penicillin Allergy

• Oral Penicillin V is the gold standard: Children receive 250 mg twice or three times daily; adolescents and adults receive 250 mg four times daily or 500 mg twice daily for 10 days 1

• Oral Amoxicillin is equally effective and often preferred in young children due to better taste acceptance: 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg) for 10 days 1, 2

• Intramuscular Benzathine Penicillin G should be used when compliance with oral therapy is questionable: <27 kg receive 600,000 units; ≥27 kg receive 1,200,000 units as a single dose 1

For Patients With Penicillin Allergy

• First-generation cephalosporins (e.g., cephalexin 20 mg/kg/dose twice daily, maximum 500 mg/dose, or cefadroxil 30 mg/kg once daily, maximum 1 g) for 10 days in patients without immediate-type hypersensitivity 1

• Clindamycin (7 mg/kg/dose three times daily, maximum 300 mg/dose) for 10 days in patients with immediate hypersensitivity to β-lactams 1

• Azithromycin (12 mg/kg once daily, maximum 500 mg) for 5 days or clarithromycin (7.5 mg/kg/dose twice daily, maximum 250 mg/dose) for 10 days, though resistance varies geographically and temporally 1

Critical Treatment Duration

The 10-day treatment course is mandatory for oral antibiotics to achieve maximal pharyngeal eradication and prevent acute rheumatic fever. 1, 2 Shorter courses with newer agents cannot be recommended despite some reports of comparable cure rates, as definitive comprehensive studies are lacking and these agents have broader spectrums and higher costs 1

Primary Treatment Goals (Prioritized by Morbidity/Mortality)

1. Prevention of acute rheumatic fever (most critical for mortality/morbidity) 1
2. Prevention of suppurative complications (peritonsillar abscess, cervical lymphadenitis, mastoiditis) 1
3. Symptom resolution and reduced transmission 1

Management of Recurrent Episodes

• Treat recurrent episodes with the same antimicrobial agents appropriate for initial illness 1

• If compliance is questionable after oral therapy, use intramuscular benzathine penicillin G 1

• For multiple recurrences, consider clindamycin or amoxicillin/clavulanate as they achieve higher pharyngeal eradication rates in carrier states 1

Management of Carriers

GAS carriers do not require identification efforts or antimicrobial therapy, as they are unlikely to spread infection or develop complications. 1 Routine post-treatment testing of asymptomatic patients who completed therapy is not recommended except in special circumstances 1

Household Contact Management

Do not routinely test or treat asymptomatic household contacts. 1 Approximately 25% of household contacts harbor GAS asymptomatically, but they are at low risk for complications 1

Common Pitfalls to Avoid

• Never use shorter antibiotic courses (<10 days for oral therapy) despite some literature suggesting efficacy, as this increases risk of rheumatic fever 1

• Avoid cephalosporins in patients with immediate-type hypersensitivity to penicillin 1

• Do not routinely retest asymptomatic patients after treatment completion, as this leads to unnecessary retreatment of carriers 1

• Distinguish between true recurrent infections and viral pharyngitis in carriers to avoid overtreatment 1

• Be aware of macrolide resistance which varies geographically and temporally when selecting azithromycin or clarithromycin 1

Special Considerations for Invasive GAS Infections

For invasive infections (necrotizing fasciitis, toxic shock syndrome), management requires:

• Immediate intensive care support with aggressive fluid resuscitation 3

• Clindamycin as adjunctive therapy due to anti-toxin effects and excellent tissue penetration 3

• Early surgical debridement of necrotic tissue in necrotizing fasciitis 3

• Intravenous immunoglobulin should be considered in toxic shock syndrome and severe invasive infections 3

• Broad-spectrum coverage initially to cover both streptococcal and staphylococcal infection until cultures available 3