Posttraumatic Pseudomonas aeruginosa Osteomyelitis in Mosul and Gaza: A Retrospective Cohort Study, 2018-2022.

Background: The history of conflicts in the Middle East has resulted in a high burden of complications from conflict-related wounds like posttraumatic osteomyelitis (PTO). This is particularly challenging to manage in settings like Mosul, Iraq and Gaza, Palestine, where healthcare systems are weakened. In nonconflict settings, PTO caused by Pseudomonas aeruginosa (PAPTO) can lead to >20% of treatment failures. We aim to describe the clinical characteristics, outcomes, and management, in PAPTO patients admitted to Médecins Sans Frontières (MSF) facilities in Mosul and Gaza between 1 April 2018 and 31 January 2022.

Methods: We conducted a retrospective cohort study on patients with PAPTO diagnosed with culture of intraoperative bone biopsy, using routinely collected data.

Results: Among 66 PAPTO episodes from 61 enrolled patients, 37.9% had a multidrug-resistant Pseudomonas aeruginosa, with higher antibiotic resistance in Gaza. Polymicrobial infections were prevalent (74.2%), mainly involving Staphylococcus aureus (74.1%), being predominantly methicillin-resistant (95.0%). Overall, 81.7% received appropriate antibiotic treatment, with monotherapy used in 60.6% of episodes and a median treatment duration of 45.5 days. Recurrence was observed in 24.6% of episodes within a median of 195 days (interquartile range, 64-440 days). No significant differences were found in recurrence rates based on the type of antibiotic treatment (mono- or dual therapy) or episode (mono- or polymicrobial).

Conclusions: Management of PAPTO in the conflict-affected, low-resource settings of Mosul and Gaza achieved a recurrence rate aligned with global reports through appropriate and targeted antibiotic use, primarily in monotherapy, provided over a mean treatment duration of 45.5 days.