Global burden of melioidosis in 2015: a systematic review and data synthesis

Background: Melioidosis is an infectious disease caused by the environmental bacterium Burkholderia pseudomallei. It is often fatal, with a high prevalence in tropical areas. Clinical presentation can vary from abscess formation to pneumonia and sepsis. We assessed the global burden of melioidosis, expressed in disability-adjusted life-years (DALYs), for 2015. Methods: We did a systematic review of the peer-reviewed literature for human melioidosis cases between Jan 1, 1990, and Dec 31, 2015. Quantitative data for cases of melioidosis were extracted, including mortality, age, sex, infectious and post-infectious sequelae, antibiotic treatment, and symptom duration. These data were combined with established disability weights and expert panel discussions to construct an incidence-based disease model. The disease model was integrated with established global incidence and mortality estimates to calculate global melioidosis DALYs. The study is registered with PROSPERO, number CRD42018106372. Findings: 2888 articles were screened, of which 475 eligible studies containing quantitative data were retained. Pneumonia, intra-abdominal abscess, and sepsis were the most common outcomes, with pneumonia occurring in 3633 (35·7%, 95% uncertainty interval [UI] 34·8–36·6) of 10 175 patients, intra-abdominal abscess in 1619 (18·3%, 17·5–19·1) of 8830 patients, and sepsis in 1526 (18·0%, 17·2–18·8) of 8469 patients. We estimate that in 2015, the global burden of melioidosis was 4·6 million DALYs (UI 3·2–6·6) or 84·3 per 100 000 people (57·5–120·0). Years of life lost accounted for 98·9% (UI 97·7–99·5) of the total DALYs, and years lived with disability accounted for 1·1% (0·5–2·3). Interpretation: Melioidosis causes a larger disease burden than many other tropical diseases that are recognised as neglected, and so it should be reconsidered as a major neglected tropical disease. Funding: European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Research Grant 2018, AMC PhD Scholarship, The Netherlands Organisation for Scientific Research (NWO), H2020 Marie Skłodowska-Curie Innovative Training Network European Sepsis Academy.