What is the treatment approach for a patient who is beta-hemolytic strep (BHS) positive but Group A strep (GAS) negative?

Treatment of Beta-Hemolytic Strep Positive, Group A Strep Negative Infections

For patients who are beta-hemolytic strep positive but Group A strep negative, treatment should focus on the specific non-Group A streptococcal organism identified, typically with appropriate antibiotics only if clinically indicated based on symptom severity and risk factors. 1

Understanding Beta-Hemolytic Streptococci

• Beta-hemolytic streptococci include several groups (A, B, C, D, F, G), with Group A (S. pyogenes) being the most common cause of bacterial pharyngitis requiring treatment 2, 3
• When a patient tests positive for beta-hemolytic strep but negative for Group A strep, they likely have one of the other groups (B, C, D, F, or G) 1
• Non-Group A streptococcal pharyngitis generally carries a lower risk of complications compared to Group A streptococcal infections 1, 4

Clinical Approach

• The Infectious Diseases Society of America guidelines emphasize that antimicrobial therapy is primarily indicated for Group A streptococcal pharyngitis, as it's the only common form of acute pharyngitis for which antibiotic therapy is definitely indicated 1
• Clinical features alone cannot reliably differentiate between the various groups of beta-hemolytic streptococci, making laboratory confirmation essential 3, 4
• For non-Group A streptococcal pharyngitis, the risk of complications such as acute rheumatic fever is significantly lower than with Group A strep 1

Treatment Recommendations

• For symptomatic non-Group A beta-hemolytic streptococcal pharyngitis with moderate to severe symptoms:

  • Penicillin V remains an appropriate first-line option: 500 mg orally four times daily for 10 days for adults 2, 5
  • Amoxicillin can be used as an alternative: 500 mg three times daily for 10 days 2, 3
  • For penicillin-allergic patients, erythromycin or first-generation cephalosporins (if no immediate hypersensitivity to β-lactams) are recommended 2, 3

• For mild cases or asymptomatic carriers of non-Group A beta-hemolytic strep:

  • Antimicrobial therapy is generally not indicated as these patients are at low risk for developing suppurative or non-suppurative complications 2, 3
  • Symptomatic treatment with antipyretics and analgesics may be sufficient 3, 4

Special Considerations

• For recurrent episodes of non-Group A streptococcal pharyngitis:

  • Consider clindamycin (300 mg four times daily for 10 days) or amoxicillin/clavulanate, which may provide better eradication rates 1
  • Azithromycin (500 mg once daily for 5 days) may be considered for patients with compliance issues 2, 6

• For persistent carriers:

  • Routine antimicrobial therapy is not recommended for asymptomatic carriers of non-Group A streptococci 2, 3
  • Routine follow-up testing after treatment is not necessary for asymptomatic individuals 2, 3

Common Pitfalls to Avoid

• Avoid unnecessary antibiotic treatment for non-Group A streptococcal pharyngitis with mild symptoms, as most cases are self-limiting 1, 4
• Do not routinely test asymptomatic household contacts of patients with streptococcal pharyngitis 1, 2
• Recognize that fever and constitutional symptoms of streptococcal pharyngitis typically disappear spontaneously within 3-4 days, even without antimicrobial therapy 1, 7
• Be aware that repeated diagnostic testing after successful treatment is not recommended for asymptomatic patients 1, 2

Remember that while Group A streptococcal pharyngitis requires antibiotic treatment to prevent complications like rheumatic fever, non-Group A streptococcal pharyngitis generally has a more benign course and may not always require antimicrobial therapy unless symptoms are severe or persistent.