Rising Incidence of Group A Streptococcal Musculoskeletal Infections in Pediatric Patients

Group A streptococcal (GAS) musculoskeletal infections (MSKI) are an increasingly recognized cause of pediatric morbidity alongside methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA, MRSA). Seasonal variation in these infections remains poorly defined. This study evaluated epidemiologic trends and seasonal patterns of pediatric MSKI at a single institution over 9 years.

We performed a retrospective review of pediatric patients surgically treated for MSKI from 2015 to 2023. Demographics, clinical presentation, laboratory and imaging findings, operative reports, and culture results were collected. Seasonal variation was analyzed using odds ratios with 95% confidence intervals and Fisher's exact tests (P ≤ .05).

Fifty-three patients requiring surgical intervention were identified (median age, 5 years [IQR 1.8 to 9.0]; 49.1% female). Culture-positive infections occurred in 70% of cases, including 13 MSSA, 8 MRSA, and 9 GAS. Eight of 9 GAS infections (89%) occurred from 2019 to 2023, representing a nearly 3-fold increase, while S. aureus infections declined 1.4-fold. Most (78%) GAS cases presented in January to May, 6 with a viral prodrome; 2 developed osteomyelitis. Seasonally, GAS infections were most frequent in fall (37.5%) compared with winter (15.4%), spring (20.0%), and summer (0%). Fall carried higher risk versus winter (odds ratio, 3.30) and spring (odds ratio, 2.40). In contrast, S. aureus infections peaked in summer (64.3%), exceeding winter (30.8%), spring (40.0%), and fall (37.5%).

GAS MSKI increased nearly 3-fold over the study period, with a 6.7-fold greater risk after 2019. These findings highlight the rising incidence and distinct seasonal patterns of pediatric GAS MSKI.