Group A streptococcal pharyngitis

Streptococcal pharyngitis, commonly called strep throat, is an infection of the pharynx caused by Streptococcus pyogenes, a gram-positive group A beta-hemolytic streptococcus ^[1]. Humans serve as the primary natural reservoir for group A streptococcus ^[1]. The infection presents as inflammation of the throat with characteristic clinical findings that distinguish it from viral pharyngitis ^[1].

The clinical presentation typically includes fever, sore throat, erythematous tonsils, and tender cervical lymphadenopathy in the anterior neck ^[1]. Additional manifestations may include headache, nausea, and vomiting ^[1]. Some patients develop scarlet fever, characterized by a diffuse sandpaper-textured rash ^[1]. Symptoms usually manifest one to three days after exposure and resolve within seven to ten days without treatment ^[1]. Some individuals may carry the bacteria asymptomatically ^[1].

Strep throat is a common bacterial infection in children ^[1]. It accounts for 15–40% of sore throats among children and 5–15% among adults ^[1]. Incidence shows seasonal variation, with cases being more frequent in late winter and early spring ^[1]. Transmission is facilitated by crowding conditions found in military and school settings ^[1].

The infection spreads through respiratory droplets from infected individuals during talking, coughing, or sneezing, or by direct contact with contaminated secretions ^[1]. Transmission can also occur through touching surfaces with infectious droplets and subsequently touching the mouth, nose, or eyes, or through contact with infected skin or sores ^[1]. Moist bacteria on objects such as toothbrushes may remain viable for up to fifteen days, though dried bacteria in dust are not considered infectious ^[1]. Food contamination is a rare but documented transmission route ^[1]. Close, direct contact with an infected person significantly increases transmission risk, particularly in crowded environments ^[1].

Primary prevention measures include frequent hand washing and avoiding sharing of eating utensils ^[1]. No vaccine is currently available for streptococcal pharyngitis ^[1]. For individuals with recurrent infections (more than three episodes per year), tonsillectomy may represent a reasonable preventive option, though benefits are modest and episodes often decrease naturally over time regardless of intervention ^[1]. Treatment of asymptomatic contacts or carriers is not recommended given the low risk of transmission and complications ^[1]. Infected individuals should remain isolated from others until fever resolves and for at least twelve hours after initiating antibiotic therapy ^[1].

1. 1Wikipedia contributors. Streptococcal pharyngitis - Wikipedia [Internet]. Wikipedia. cited 3 Sept 2026.Available from: https://en.wikipedia.org/wiki/Streptococcal_pharyngitis
2. 2Sun X et al. Efficacy and safety of 24 antibiotics for group A streptococcal pharyngitis: a network meta-analysis of 64 randomized controlled trials. Front Public Health. 2026. PMID: 42440760. doi: 10.3389/fpubh.2026.1848949.PubMed: https://pubmed.ncbi.nlm.nih.gov/42440760/