What is the treatment for a Group G streptococcal (GGS) positive throat culture?

Treatment of Group G Streptococcal Pharyngitis

Group G streptococcus (GGS) pharyngitis should be treated similarly to Group A streptococcal pharyngitis with penicillin or amoxicillin for 10 days, as the available guidelines and evidence focus on Group A streptococcus but the same antibiotic principles apply to other beta-hemolytic streptococci including Group G.

Important Clinical Context

The provided evidence exclusively addresses Group A streptococcal (GAS) pharyngitis, not Group G streptococcus. However, Group G streptococcus is also a beta-hemolytic streptococcus that causes pharyngitis and responds to the same antibiotics as Group A streptococcus. In clinical practice, Group G streptococcal pharyngitis is managed with identical antibiotic regimens.

First-Line Treatment Approach

• Penicillin remains the treatment of choice due to its proven efficacy, safety, narrow spectrum, and low cost 1

• Oral penicillin V dosing:

  • Children: 250 mg twice or three times daily for 10 days 2
  • Adolescents and adults: 250 mg four times daily or 500 mg twice daily for 10 days 2

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

• Intramuscular benzathine penicillin G is preferred for patients unlikely to complete a full 10-day oral course 1

Alternative Antibiotics for Penicillin-Allergic Patients

• For non-immediate hypersensitivity reactions: First-generation cephalosporins (e.g., cephalexin 20 mg/kg twice daily, maximum 500 mg/dose) for 10 days 2, 3

• For immediate-type hypersensitivity: Clindamycin for 10 days (7 mg/kg three times daily, maximum 300 mg/dose) 4, 2

• Macrolides (erythromycin, azithromycin) are suitable alternatives, though macrolide resistance should be considered, particularly with multiple prior macrolide courses 1, 4, 2

Critical Treatment Duration

• A full 10-day course is mandatory for all oral antibiotics except azithromycin to achieve maximal pharyngeal eradication and prevent complications 2, 3

• Azithromycin requires only 5 days due to its prolonged tissue half-life 3

• Shorter courses increase the risk of treatment failure and complications 2, 3

Treatment Goals (in Priority Order)

1. Prevention of suppurative complications (peritonsillar abscess, cervical lymphadenitis, mastoiditis) - this is the primary concern with Group G streptococcus, as acute rheumatic fever is primarily associated with Group A streptococcus 2

2. Abatement of clinical symptoms and reduction in transmission to close contacts 1

3. Minimization of adverse effects from inappropriate antimicrobial therapy 1

Common Pitfalls to Avoid

• Do not use shorter antibiotic courses (<10 days for oral therapy) despite some literature suggesting efficacy 2

• Avoid routine post-treatment testing in asymptomatic patients who completed therapy, as this leads to unnecessary retreatment of carriers 4, 2

• Do not prescribe tetracyclines, sulfonamides, trimethoprim-sulfamethoxazole, or older fluoroquinolones, which are not effective against streptococci 4

• Avoid cephalosporins in patients with immediate-type hypersensitivity to penicillin due to 10% cross-reactivity risk 2, 3

Management of Treatment Failure or Recurrence

• Perform throat culture if symptoms persist or recur after completing therapy 4

• Consider alternative antibiotics such as clindamycin, amoxicillin-clavulanate, or first-generation cephalosporins for retreatment 4, 2

• Clindamycin is particularly effective for eradicating streptococci in carrier states and recurrent episodes 4, 5

• Evaluate for carrier state with intercurrent viral infection, non-compliance, or new infection from contacts 4, 2