Diagnosing pediatric skeletal system infections: you are as good as your lab

Pediatric skeletal system infections are medical emergencies that may cause severe acute complications and long-term orthopedic disabilities. Because the clinical presentation of septic arthritis and osteomyelitis may mimic non-infectious conditions, early identification of the causative agent and determination of its antibiotic susceptibility profile are cornerstones of patient management. The etiology of childhood skeletal system infections has changed over time, reflecting the implementation of conjugate vaccines against Haemophilus influenzae type b and Streptococcus pneumoniae, as well as the development of sensitive molecular detection tests. These novel laboratory methods, coupled with rapid pathogen identification by MALDI-TOF technology, have reduced the fraction of "culture-negative" infections and shortened the turnaround time for pathogen identification from days to hours. However, even today, a substantial fraction of bone and joint infections remains microbiologically unconfirmed. Metagenomic next-generation sequencing holds great promise, but its high cost, the need for technical expertise, and the detection of commensal organisms of dubious significance severely limit its routine use. On the other hand, metagenomic next-generation sequencing has not expanded the list of known pediatric skeletal system pathogens, suggesting that underutilization of current diagnostic methodologies, rather than reduced sensitivity, drives suboptimal diagnosis.