What is Streptococcus A (Strep A)?

From the Guidelines

Strep A, or Group A Streptococcus, is a bacterial infection that commonly causes strep throat but can also lead to skin infections, scarlet fever, and rarely, more serious conditions. The diagnosis of Strep A is typically confirmed by culture or rapid antigen detection testing (RADT) 1. The recommended treatment for Strep A infections is antibiotics, with penicillin being the first-line treatment, as it has been proven to be effective in eradicating the infecting organism from the pharynx and preventing complications like rheumatic fever 1. For adults with strep throat, penicillin V 500 mg orally twice daily for 10 days is typically prescribed 1. For children, the dosage is adjusted based on weight, usually 250 mg twice daily for those under 27 kg 1. Alternatives for penicillin-allergic patients include azithromycin (500 mg once daily for 5 days for adults) or clindamycin (300 mg three times daily for 10 days) 1. It's crucial to complete the full course of antibiotics even if symptoms improve, as this prevents complications like rheumatic fever and kidney inflammation 1. Patients should rest, stay hydrated, use throat lozenges for pain relief, and gargle with salt water. Symptoms typically improve within 48 hours of starting antibiotics, and patients are no longer contagious after 24 hours of antibiotic treatment. Strep A spreads through respiratory droplets and close contact, so practicing good hygiene and avoiding sharing personal items can prevent transmission 1. Key points to consider in the management of Strep A infections include:

• Accurate diagnosis to prevent inappropriate administration of antimicrobials
• Selection of the most appropriate antimicrobial therapy based on specificity, safety, and cost
• Completion of the full course of antibiotics to prevent complications
• Prevention of transmission through good hygiene practices.

From the FDA Drug Label

Streptococci in groups A, C, G, H, L, and M are very sensitive to penicillin. (group A β-hemolytic streptococcus)

• Streptococcus A (Strep A) refers to a type of bacteria, specifically group A β-hemolytic streptococcus.
• It is a bacterium that is sensitive to penicillin 2, 3.

From the Research

Definition of Streptococcus A (Strep A)

• Streptococcus A, also known as group A beta-haemolytic streptococci (GABHS), is a type of bacteria that is a common cause of pharyngitis, particularly in children and adolescents 4, 5, 6, 7, 8.
• GABHS is a bacterial infection that can lead to acute rheumatic fever and other complications if left untreated or inadequately treated 4, 5, 7.

Characteristics of Streptococcus A Infections

• Streptococcal pharyngitis usually cannot be reliably distinguished from other etiologies on the basis of epidemiologic or physical findings, and therefore a throat culture or a rapid antigen detection test is generally necessary to confirm the diagnosis 5, 6, 7.
• The symptoms of streptococcal pharyngitis include fever, tonsillar exudate, cervical lymphadenitis, and sore throat, while a cough is more suggestive of a viral etiology 6.
• All isolates of GABHS are sensitive to penicillins and cephalosporins, whereas resistance to macrolides has been identified in some geographic regions 5, 6, 7.

Treatment and Management of Streptococcus A Infections

• The recommended first-line therapy for streptococcal pharyngitis is a 10-day course of penicillin V, usually given 2 or 3 times per day 5, 6, 8.
• Alternative treatments include other penicillins, macrolides, and cephalosporins, with cephalosporins offering higher bacteriologic eradication rates than penicillin V 4, 5, 6.
• A strategy based on the use of a clinical diagnostic score, followed by a rapid test if the score is intermediate, seems to be the best way of restricting antibiotics to patients with pharyngitis due to group A streptococci 7.