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

Abstract

Background The long history of conflicts in the Middle East has resulted in a high burden of complications from conflict-related wounds like post-trauma osteomyelitis (PTO). This is particularly challenging to manage in settings like Mosul, Iraq and Gaza, Palestine, where healthcare systems are weakened. In non-conflict settings, PTO caused by Pseudomonas aeruginosa (PAPTO) can lead to >20% of treatment failures. This is twice the relapse rate as with other causes of PTO. We aim to describe the clinical characteristics, outcomes, and management, including appropriateness of antibiotic treatment, in PAPTO patients admitted to Médecins Sans Frontières (MSF) facilities in Mosul (Iraq) and Gaza (Palestine) between 01-April-2018 and 31-January-2022. Methods We conducted a retrospective cohort study on patients with PAPTO diagnosed with culture of intraoperative bone biopsy. We reviewed routinely collected patient data to describe the characteristics of PAPTO patients and episodes, antibiotic resistance patterns, polymicrobial infections, and the appropriateness of antibiotic treatment in comparison to the clinical guidelines followed. Differences between Mosul and Gaza were analysed using Pearson chi-square or Fisher exact tests for categorical variables, and unpaired t-tests or Wilcoxon Mann-Whitney tests for continuous variables, as appropriate. Results Among 66 PAPTO episodes from 61 enrolled patients who were hospitalized for a median of 42 days [interquartile range (IQR): 24-53], 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%), of which predominantly methicillin-resistant (MRSA) (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 (IQR: 64-440). Within the overall cohort, no significant differences were found in recurrence rates based on the type of antibiotic treatment (mono- or dual therapy) or the type of 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.