Bone and joint infections due to melioidosis; diagnostic and management strategies to optimise outcomes.

Background: Melioidosis, a life-threatening infection caused by the gram negative bacterium Burkholderia pseudomallei, can involve almost any organ. Bone and joint infections (BJI) are a recognised, but incompletely defined, manifestation of melioidosis that are associated with significant morbidity and mortality in resource-limited settings. Methodology/principal findings: We identified all individuals with BJI due to B. pseudomallei managed at Cairns Hospital in tropical Australia between January 1998 and June 2023. The patients' demographics, their clinical findings and their treatment were correlated with their subsequent course. Of 477 culture-confirmed cases of melioidosis managed at the hospital during the study period, 39 (8%) had confirmed BJI; predisposing risk factors for melioidosis were present in 37/39 (95%). However, in multivariable analysis only diabetes mellitus was independently associated with the presence of BJI (odds ratio (95% confidence interval): 4.04 (1.81–9.00), p = 0.001). BJI was frequently only one component of multi-organ involvement: 29/39 (74%) had infection involving other organs and bacteraemia was present in 31/39 (79%). Of the 39 individuals with BJI, 14 (36%) had osteomyelitis, 8 (20%) had septic arthritis and 17 (44%) had both osteomyelitis and septic arthritis; in 32/39 (83%) the lower limb was involved. Surgery was performed in 30/39 (77%). Readmission after the initial hospitalisation was necessary in 11/39 (28%), 5/39 (13%) had disease recrudescence and 3/39 (8%) had relapse; 4/39 (10%) developed pathological fractures. ICU admission was necessary in 11/39 (28%) but all 11 of these patients survived. Only 1/39 (3%) died, 138 days after admission, due to his significant underlying comorbidity. Conclusions: The case-fatality rate from melioidosis BJI in Australia's well-resourced health system is very low. However, recrudescence, relapse and orthopaedic complications are relatively common and emphasise the importance of collaborative multidisciplinary care that includes early surgical review, aggressive source control, prolonged antibiotic therapy, and thorough, extended follow-up. Author summary: Bone and joint infections (BJI) are a recognised and life-threatening manifestation of melioidosis but frequently only one component of multi-organ involvement. Almost all patients with BJI due to Burkholderia pseudomallei have risk factors that predispose them to developing melioidosis, but diabetes appears to be the most closely associated with BJI. The vasculopathy, neuropathy, structural deformity and decreased immunity that is seen in many individuals with diabetes increases their risk of lower limb infection and these factors–combined with greater exposure to B. pseudomallei in the soil and surface water–might explain the lower limb predominance that is seen in many series of melioidosis-related BJI. Patients require early multimodal imaging, appropriate microbiological sampling, early surgical review, prompt source control and an adequate duration of antibiotic therapy–and, in many cases, critical care support–to ensure optimal outcomes. Collaborative, multidisciplinary care reduces the case-fatality rate of melioidosis BJI, but recrudescence, relapse and orthopaedic complications are common in survivors and therefore extended patient follow up is essential. [ABSTRACT FROM AUTHOR]