Molecular and clinical characterization of Group A Streptococcal pharyngitis in Iraqi children, Wasit Province, 2025

Background: Streptococcus pyogenes (Group A Streptococcus, GAS) is a leading bacterial cause of pediatric pharyngitis and a precursor to acute rheumatic fever. Contemporary data from Iraq are scarce. Objective: To characterize the clinical presentation, diagnostic accuracy, molecular epidemiology (emm types, virulence genes), and antimicrobial susceptibility of GAS among children in Wasit Province, Iraq. Methods: A prospective hospital-based study enrolled 260 children aged 3–15 years with acute sore throat from January to March 2025 across three pediatric facilities in Al-Kut. Inclusion criteria: fever >38.5°C, tonsillar exudate or cervical lymphadenopathy, absence of cough; exclusion: recent antibiotic use or immunocompromise. Throat culture (gold standard), rapid antigen detection test (RADT), and PCR for emm, speA, ermB, and mefA were performed. Antimicrobial susceptibility was tested by disk diffusion. Results: GAS prevalence was 19.6% (51/260). Key clinical features: fever (94.1%), exudate (88.2%). RADT sensitivity/specificity: 84.3% / 98.6%; PCR: 96.1% / 99.5%. Dominant emm types: emm1 (35.3%), emm12 (29.4%), emm28 (19.6%); speA in 64.7%. All isolates penicillin-susceptible; erythromycin resistance: 3.9% (ermB-positive). Amoxicillin prescribed in 82.4%; 94.1% improved within 72 hours. Conclusions: GAS remains prevalent in Iraqi children with distinct molecular and clinical patterns. RADT is useful but less sensitive than PCR. Findings support local adaptation of guidelines, antibiotic stewardship, and winter-targeted public health interventions to prevent complications and align with SDG 3.