Prevalence and Mortality Outcomes of Melioidosis in Thalassemia: A Systematic Review and Meta-Analysis.

Background. Melioidosis is a severe infection caused by Burkholderia pseudomallei and is endemic in regions with a high prevalence of thalassemia. Patients with thalassemia are thought to be at increased risk due to iron overload, splenectomy, and immune dysfunction. However, the pooled prevalence and mortality outcomes of melioidosis in this population remain unclear. Methods. We conducted a systematic review and meta-analysis in accordance with PRISMA 2020 guidelines (PROSPERO: CRD420251108294). PubMed, Embase, and Scopus were searched from inception to July 2025. Observational studies reporting prevalence or mortality of melioidosis in patients with thalassemia were eligible. Pooled odds ratios (ORs) for mortality were calculated using random-effects models, with subgroup and sensitivity analyses based on age, thalassemia subtype, and study quality. Results. Six retrospective studies including 7529 melioidosis patients, of whom 173 had thalassemia, were analyzed. The prevalence of thalassemia among melioidosis cases ranged from 0.5% to 40.7%. Mortality among thalassemia patients varied from 0% to 100%. Pooled analysis demonstrated no significant excess mortality compared with non-thalassemia controls (OR 0.55, 95% CI 0.16-1.89; I2 = 44.9%). Sensitivity analysis restricted to moderate- and high-quality studies showed a significantly lower risk of death (OR 0.23, 95% CI 0.15-0.36; I2 = 0%). Subgroup analyses by thalassemia subtype and age revealed no clear effect modification, although power was limited. Conclusions. Despite biological plausibility, thalassemia was not associated with increased melioidosis mortality. These findings suggest that closer clinical monitoring, iron chelation, and comorbidity profiles may influence outcomes. Prospective, well-characterized cohort studies are needed to refine risk stratification and guide management in endemic regions.