Should antibiotics be administered if a throat culture is positive for Group A beta-hemolytic Streptococcus (GABHS)?

From the Guidelines

Yes, antibiotics should be given if a throat culture is positive for strep (group A Streptococcus). The first-line treatment is penicillin, typically penicillin V potassium 500 mg orally twice daily for 10 days for adults, or amoxicillin 50 mg/kg (maximum 1000 mg) once daily for 10 days for children, as recommended by the American Heart Association 1 and the Infectious Diseases Society of America 1. For patients with penicillin allergy, alternatives include cephalexin 500 mg twice daily for 10 days (if no anaphylactic reaction history), or macrolides like azithromycin 500 mg on day 1 followed by 250 mg daily for 4 more days.

Key Considerations

• Treatment is important even if symptoms are mild or resolving because it prevents complications like rheumatic fever, reduces symptom duration, decreases contagiousness, and prevents spread to others, as highlighted in the 2016 guidelines from the American College of Physicians and the Centers for Disease Control and Prevention 1.
• Patients should complete the full antibiotic course even if feeling better and can typically return to school or work 24 hours after starting antibiotics when they're no longer contagious.
• The choice of antibiotic should be based on the patient's medical history, including any allergies, and the severity of the infection.

Additional Guidance

• Chronic streptococcal carriers usually do not need to be identified or treated with antibiotics, as they are at little risk for development of rheumatic fever and are not important in the spread of GAS to individuals who live and work around them 1.
• Routine testing for other bacterial causes of pharyngitis is not recommended, but clinicians should remain vigilant and suspect rare conditions such as Lemierre syndrome in adolescent and young adult patients with severe pharyngitis 1.

From the FDA Drug Label

In streptococcal infections, therapy must be sufficient to eliminate the organism (10-day minimum); otherwise the sequelae of streptococcal disease may occur.

Pharyngitis/Tonsillitis In three double-blind controlled studies, conducted in the United States, azithromycin (12 mg/kg once a day for 5 days) was compared to penicillin V (250 mg three times a day for 10 days) in the treatment of pharyngitis due to documented Group A β-hemolytic streptococci (GABHS or S. pyogenes)

Yes, antibiotics should be given if a throat culture is positive for strep. The recommended treatment is either penicillin V for 10 days or azithromycin for 5 days, as supported by studies 2 and 3. Antibiotic therapy must be sufficient to eliminate the organism to prevent the sequelae of streptococcal disease. Key points to consider:

• Treatment duration: A minimum of 10 days for penicillin V
• Alternative treatment: Azithromycin for 5 days
• Importance of completion: Completing the full course of therapy is crucial to ensure the effectiveness of the treatment and prevent the development of antibiotic-resistant bacteria.

From the Research

Throat Culture Positive for Strep

• If a throat culture is positive for strep, antibiotics should be given to alleviate symptoms, shorten the duration of the illness, and prevent complications such as acute rheumatic fever and post-streptococcal glomerulonephritis 4, 5, 6.
• Penicillin is the treatment of choice due to its cost-effectiveness, narrow spectrum of activity, and proven efficacy, with amoxicillin being an equally effective alternative 5, 6.
• For patients allergic to penicillin, macrolides, oral cephalosporins, and other beta-lactam agents are acceptable alternatives 5, 6.

Duration of Antibiotic Treatment

• The duration of antibiotic treatment is typically 10 days of oral therapy or one injection of intramuscular benzathine penicillin 6.
• It is recommended that patients complete a full 24 hours of antibiotics before returning to school or daycare to minimize the risk of transmission to close contacts 7, 8.

Effectiveness of Antibiotics

• Antibiotics have been shown to provide only modest benefits in treating sore throat, although effectiveness increases in participants with positive throat swabs for group A beta-haemolytic streptococci (GABHS) 4.
• The evidence is insufficient to show clinically meaningful differences between antibiotics for GABHS tonsillopharyngitis, but limited evidence suggests that cephalosporins may be more effective than penicillin for relapse in adults, and carbacephem may be more effective for symptom resolution in children 4.