1690. Acute Hematogenous Osteoarticular Infections in Children at Siriraj Hospital, Thailand: A 20-Year Retrospective Review

BACKGROUND: Acute hematogenous osteomyelitis (AHO) and septic arthritis (SA) lead to significant morbidity and sequelae. There are limited data in Thai children. METHODS: This is a single-center retrospective study of patients aged < 18 years who were diagnosed with AHO and SA between 2002- 2021. The acute onset of AHO and SA was defined as the diagnosis of bone and joint infection within 4 weeks after the onset of symptoms or signs in a previously uninfected bone. Data were collected and factors associated with sequelae were determined by using multiple logistic regression analyses. RESULTS: Of the 110 patients identified, 19 were AHO, 81 were SA, and 10 were combined AHO and SA. The median (IQR) age was 6.7 (1.4-11.9) years and 66 (60%) were male. Fifteen (13.6%) patients were immunocompromised. The most common sites of AHO were tibia (27.6%) and femur (27.6%), and of SA were hips (41.8%) and knees (31.9%). The pathogens were identified in 68 of 106 (64.1%) patients with specimen submission. The positivity rate of hemoculture, synovial fluid, synovial tissues, bone biopsies and vaginal/urethral culture in patients with suspected disseminated gonococcal infection were 32.1%, 40%, 61.9%, 60% and 50% respectively. The most common organisms were methicillin-sensitive Staphylococcus aureus (30.2%) and non-typhoidal Salmonella (9.4%). We found only one case with community-acquired, methicillin-resistant S.aureus. Non-typhoidal Salmonella was responsible for 22.7% of 22 infants. The one-year sequelae were found in 15.8% of AHO, 18.5% of SA, and 20% of combined. In multivariate models, factors associated with sequelae were being immunocompromised (adjusted OR 14.16, 95%CI 1.96-102.35, P=0.009) and infection of the hips (adjusted OR 6.25, 95%CI 1.45-14.59, P=0.025). Patients' characteristics [Figure: see text] Pathogens according to age groups [Figure: see text] Factors associated with sequalae [Figure: see text] CONCLUSION: Methicillin-sensitive S. aureus was the most common pathogen among Thai children with acute hematogenous osteoarticular infections. However, Salmonella was the predominant causative organism among infants. Appropriate empirical antibiotic therapy should be effective against both pathogens in infants. Long-term follow up is needed particularly in immunocompromised children and infection of the hip. DISCLOSURES: All Authors: No reported disclosures