380. Characterizing Host Factors, Treatment Strategy, and Clinical Outcomes of Group A Streptococcus Orthopedic Infections

Abstract

BackgroundThe annual incidence of invasive β-hemolytic group A streptococcus (GAS) infections in the United States is approximately 3.8 cases per 100,000 patients with 10–30% mortality. But data in GAS orthopedic infections is limited. We sought to characterize patient factors, medical and surgical management, and clinical outcomes from GAS orthopedic infections at our medical center.MethodsA total of 12 patients with GAS orthopedic infections (necrotizing fasciitis, osteomyelitis, prosthetic joint infection, septic arthritis, or tenosynovitis) from July 2017 and March 2019 were included. Medical records were reviewed for site of positive GAS culture (blood, wound, joint fluid, or tissue cultures), demographics, comorbidities, surgical management, and antibiotic regimen and duration. The primary outcome was cure at 90 days defined as clinical improvement without recurrent or new infection, or further surgical or medical management at 90 days after treatment completion. The secondary outcome was erythrocyte sedimentation rates (ESR) before and after treatment.ResultsThe median age of the 12 patients was 56 years (range 3–75); 58% were female and 58% had a body mass index ≥30 kg/m2. The median Charlson comorbidity index score was 3 (range 0–7) with 58% having diabetes mellitus. Two patients had either rheumatoid arthritis or monoclonal gammopathy (Table 1). Most patients had severe infections; 33% with necrotizing fasciitis and 25% with orthopedic implants. All patients had an elevated initial ESR, including 75% with ESR >40 mm/h. 92% required surgery, including 42% amputations and 17% prosthesis removals. Patients were mostly treated with β-lactams and vancomycin (92%); only 50% received clindamycin or linezolid. Most patients (75%) required at least 2 weeks of antibiotics. Five patients (42%) were not cured at 90 days, and 1 died of infectious complications (Table 2).ConclusionSevere GAS orthopedic infections necessitate both surgical management and prolonged antibiotics. 42% of our patients were not cured at 90 days and most eventually required amputation. Toxin mediators, clindamycin and linezolid, were underutilized. Chronic suppressive antibiotics should be considered for patients with orthopedic implants, especially those with durable immune suppression. Disclosures All authors: No reported disclosures.