Osteomyelitis and Septic Arthritis in the Darwin Prospective Melioidosis Study

Melioidosis is a multisystem infectious disease caused by the environmental bacterium Burkholderia pseudomallei. Osteomyelitis (OM) and septic arthritis (SA) are uncommon primary presentations for melioidosis but important secondary foci, often requiring prolonged therapy and multiple surgeries. We characterized the epidemiology, presentation, treatment, and outcomes of patients from 24 years of the Darwin Prospective Melioidosis Study (DPMS).

DPMS patients from October 1, 1999, until September 30, 2023, were included if they had a primary or secondary diagnosis of OM or SA. Epidemiological, risk factor, clinical, and outcome data were retrieved from the DPMS database. Antibiotic and surgical data were collated from patient records.

From 1129 consecutive patients with culture-confirmed melioidosis, 122 (10.8%) had OM and/or SA, with 115 evaluable. Ninety-four of 1129 (8.3%) had OM, and 62/1129 (5.5%) had SA, with 41/115 (35.7%) of these having both OM and SA. Many combined infections involved contiguous bone and joints or soft tissue. Fifty-nine (51.3%) were male, and only 4.3% were ≤16 years old. Diabetes mellitus was present in 69.6%, and only 12.2% had no identifiable clinical risk factor. There were 8 deaths (7.0%) and 20 (17.4%) recurrent infections. Seventy-one (61.7%) had operative management, with combined infection associated with more procedures and longer length of stay.

The current paradigm of care for osteoarticular melioidosis involves prolonged intravenous antibiotics in conjunction with timely and complete operative management, and in our setting where these are available, outcomes are good. In many melioidosis-endemic regions these resources are limited, and mortality remains high.