Kingella kingae septic arthritis

Area of Science:

• Pediatric infectious diseases
• Orthopedic surgery
• Clinical microbiology

Background:

• Septic arthritis in children requires prompt diagnosis and treatment.
• Kingella kingae is an increasingly recognized pathogen in pediatric septic arthritis.
• Distinguishing K. kingae from other causative organisms is important for appropriate management.

Purpose of the Study:

• To compare patient demographics, clinical features, and blood parameters in K. kingae septic arthritis versus septic arthritis caused by other organisms.
• To assess the diagnostic utility of polymerase chain reaction (PCR) for K. kingae detection.
• To inform clinical suspicion and diagnostic strategies for pediatric septic arthritis.

Main Methods:

• Prospective case series of children with suspected septic arthritis at a UK pediatric institution (October 2012 - November 2018).
• Inclusion of clinical, biochemical, and microbiological data, including culture and PCR analysis.
• Comparison of findings between K. kingae-positive cases and those with other organisms or no identified pathogen.

Main Results:

• Kingella kingae was the most common organism (42%) in culture- and/or PCR-positive septic arthritis cases.
• K. kingae infections were predominantly diagnosed by PCR (66%), with routine cultures often negative.
• K. kingae-positive patients were significantly younger (mean 16.1 months) with lower CRP and higher ESR/CRP ratios compared to other organisms.

Conclusions:

• Kingella kingae is the leading cause of pediatric septic arthritis, frequently requiring PCR for diagnosis.
• Clinical suspicion for K. kingae should be maintained in young children with atypical presentations.
• Routine PCR testing is recommended for suspected pediatric septic arthritis to improve K. kingae detection.