Osteoarticular Infections Caused by Kingella kingae in Children: A 12-year Experience from a Tertiary Hospital in Northern Portugal

Objective: To analyze the clinical, laboratory, and microbiological characteristics of confirmed osteoarticular infections (OAI) caused by <i>Kingella kingae</i> in children, based on a 12-year experience from a tertiary hospital in northern Portugal. Methods: Retrospective observational study of patients aged 0–18 years with microbiologically confirmed OAI due to <i>K. kingae</i> between January, 2012 and December, 2023. Confirmation required positive polymerase chain reaction (PCR) for <i>K. kingae</i> DNA in synovial fluid or bone tissue. Data were analyzed using SPSS® version 27. Results: Twenty cases of confirmed OAI by <i>K. kingae</i> were identified. Median age was 1 year (range: 1–15 years). Sex distribution was equal (50% male). The most frequent clinical manifestations were arthralgia (55%), limping (50%), and fever (40%). Upper respiratory tract infection (URTI) occurred before or during the OAI episode in 45% of cases. Septic arthritis was the predominant form (80%), followed by osteomyelitis (15%) and spondylodiscitis (5%). PCR was positive in 100% of tested synovial fluids and bone biopsies, whereas traditional cultures failed to isolate <i>K. kingae</i> in all cases. All patients required surgical intervention. Treatment with beta-lactams resulted in full recovery with no sequelae reported. Conclusions: OAI caused by <i>K. kingae</i> primarily affects young children with mild clinical presentation. PCR is essential for diagnosis, as traditional cultures invariably fail to isolate this fastidious organism. Early recognition and targeted treatment lead to favorable outcomes without long-term complications. How to cite this article: Fraga C, Neto M, Capela J, <i>et al.</i> Osteoarticular Infections Caused by <i>Kingella kingae</i> in Children: A 12-year Experience from a Tertiary Hospital in Northern Portugal. Pediatr Inf Dis 2025;7(4):125–130.