Paediatric Bone and Joint Infections: causative organisms and antibiotic treatment

Background
Osteomyelitis (OM) and septic arthritis (SA) are uncommon in children in Western populations1. Resistant and virulent organisms including MRSA and Panton-Valentine Leukocidin–producing (PVL) Staphylococcus aureus make effective treatment challenging2. Current data suggest incidence of PVL-producing Staphylococcus Aureus is low in the UK and more commonly associated with MSSA than in North America.

Methods
31 paediatric patients from Sandwell and West Birmingham Hospitals NHS Trust coded as OM or SA between 2010 and 2016 were identified retrospectively. Data were accessed from casenotes (n=21) and electronically. Rates of OM or SA caused by PVL-producing Staphylococcus aureus were compared to recent literature and patients’ treatment reviewed. 

Results
There were 25 confirmed cases of OM, one SA. Age range was 2 weeks - 16 years. (Median age 8 years). 
Microbiological findings included positive blood cultures, with Staphylococcus aureus identified in six patients’ blood (five MSSA, one MRSA). Five samples were PVL-producers, including the MRSA. Streptococci were cultured in two. Intra-operative samples (n=11) revealed MSSA as the most common organism (n=10). One was MRSA. PVL-production wasn't identified in these. Patients with PVL-producing staphylococcus infections all required operative management; longer antibiotic courses (median 12 weeks versus 6 weeks for non-PVL) and had more complications. They also required broader-spectrum antibiotic cover to achieve response. They did, though make a good recovery.

Conclusions
83% of staphylococci in blood cultures were PVL-producers, a higher proportion than suggested by other European data3. These patients provide a treatment challenge, often requiring broader-spectrum antibiotic therapy. Therefore, obtaining samples for culture and testing for PVL-production is essential to optimise therapy. Our patients had no long-term disability. Sample size was small, however, our results correlate with London regarding low UK incidence of PVL-positive MRSA.

PAEDIATRIC BONE AND JOINT INFECTIONS: CAUSATIVE ORGANISMS AND ANTIBIOTIC TREATMENT