Outcomes of patients with suspected or confirmed melioidosis: A prospective multinational, multicenter, observational study
8 affiliations
- 1Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao People's Democratic Republic
- 2Mahosot Hospital, Vientiane, Lao People's Democratic Republic
- 3Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- 4Department of Medicine, Sunpasitthiprasong Hospital, Ubon Ratchathani, Thailand
- 5Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- 6Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- 7AN2 Therapeutics, Menlo Park, California, United States of America
- 8Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
Abstract
Background: Melioidosis is an infectious disease caused by the Gram-negative bacterium Burkholderia pseudomallei. The disease is difficult to diagnose and treat. Here, we investigated outcomes of patients with suspected or confirmed melioidosis in Laos and Thailand. Methodology: We conducted a prospective, multinational, multicenter, observational study at Mahosot Hospital (MH) in Laos, and Srinagarind Hospital (SRH) and Sunpasitthiprasong Hospital (SUH) in Thailand. We enrolled adult patients (age ≥ 18 years) with suspected or confirmed melioidosis. For suspected-melioidosis cases, patients who had septic shock, had sepsis with at least one risk factor associated with melioidosis (including diabetes mellitus, chronic kidney disease, thalassemia major, malignancy and immunosuppressive therapy) or were prescribed ceftazidime or meropenem by attending physicians were enrolled, provided they were within 24 hours of hospitalization at the study hospitals. For confirmed-melioidosis cases, patients who had a clinical specimen tested positive for B. pseudomallei by either culture or antigen-detection immunofluorescence microscopy were enrolled. The primary endpoints were 28-day and 90-day mortality. Principal findings: From November 2023 to October 2024, 627 patients were screened and 200 patients were enrolled (43 for suspected-melioidosis and 157 for confirmed-melioidosis). Five of 43 patients enrolled with suspected-melioidosis (12%) were subsequently diagnosed with culture-confirmed melioidosis since enrollment. 28-day and 90-day mortality were 14% (6/43) and 23% (10/43) in suspected-melioidosis patients, respectively; and 25% (39/157) and 36% (57/157) in confirmed-melioidosis patients, respectively. In multivariable Cox regression models, higher Sequential Organ Failure Assessment (SOFA) score at enrollment and intensive care unit (ICU) admission on the day of enrollment were strongly associated with mortality outcomes. Admission to SRH and longer duration of symptoms prior to enrollment were independently associated with survival outcomes. Conclusions: Future clinical trials aiming to reduce mortality in patients with suspected or confirmed melioidosis should consider stratification based on the severity of organ dysfunction at enrollment. Differences in mortality between study sites may reflect residual confounding and should be carefully considered in sample size calculations. Author summary: Melioidosis is a frequently fatal infection caused by the soil bacterium Burkholderia pseudomallei and is a major cause of sepsis in Southeast Asia. Because the bacterium is intrinsically resistant to many commonly used antibiotics and melioidosis is difficult to diagnose using clinical presentation alone, clinicians often initiate empirical antibiotic therapy effective against B. pseudomallei once the disease is suspected. Treatment is continued for a complete course once the diagnosis is confirmed by bacterial culture results. However, patients treated for “suspected” melioidosis are seldom studied, and the factors associated with mortality in melioidosis remain poorly defined, in part because few studies have spanned more than one country. We prospectively followed 200 adults admitted with suspected or confirmed melioidosis at three hospitals in Laos and Thailand for 90 days. 90-day mortality was high in patients with both suspected and confirmed melioidosis. Factors associated with mortality included the severity of organ failure and intensive-care admission at enrollment, whereas a longer duration of symptoms before enrollment and care at one study hospital were associated with survival. These findings suggest that future trials aiming to reduce melioidosis mortality should account for organ-failure severity and between-hospital differences when designing patient selection and calculating sample size.
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BibTeX
@article{phommasone2026outcomes,
title = {{Outcomes of patients with suspected or confirmed melioidosis: A prospective multinational, multicenter, observational study}},
author = {Koukeo Phommasone and Siriluck Anunnatsiri and Suwatthiya Kitsaran and Sue J. Lee and Pankham Vongphachanh and Ko Chang and George H. Talbot and Kevin O’Shea and Paul B. Eckburg and Stephen D. Prior and Elizabeth A. Ashley and Nicholas P. J. Day and Direk Limmathurotsakul},
journal = {PLOS Neglected Tropical Diseases},
year = {2026},
month = sep,
doi = {10.1371/journal.pntd.0014562},
url = {https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014562},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Outcomes of patients with suspected or confirmed melioidosis: A prospective multinational, multicenter, observational study
AU - Koukeo Phommasone
AU - Siriluck Anunnatsiri
AU - Suwatthiya Kitsaran
AU - Sue J. Lee
AU - Pankham Vongphachanh
AU - Ko Chang
AU - George H. Talbot
AU - Kevin O’Shea
AU - Paul B. Eckburg
AU - Stephen D. Prior
AU - Elizabeth A. Ashley
AU - Nicholas P. J. Day
AU - Direk Limmathurotsakul
PY - 2026
DA - 2026/09/08
JO - PLOS Neglected Tropical Diseases
DO - 10.1371/journal.pntd.0014562
UR - https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014562
AB - Background: Melioidosis is an infectious disease caused by the Gram-negative bacterium Burkholderia pseudomallei. The disease is difficult to diagnose and treat. Here, we investigated outcomes of patients with suspected or confirmed melioidosis in Laos and Thailand. Methodology: We conducted a prospective, multinational, multicenter, observational study at Mahosot Hospital (MH) in Laos, and Srinagarind Hospital (SRH) and Sunpasitthiprasong Hospital (SUH) in Thailand. We enrolled adult patients (age ≥ 18 years) with suspected or confirmed melioidosis. For suspected-melioidosis cases, patients who had septic shock, had sepsis with at least one risk factor associated with melioidosis (including diabetes mellitus, chronic kidney disease, thalassemia major, malignancy and immunosuppressive therapy) or were prescribed ceftazidime or meropenem by attending physicians were enrolled, provided they were within 24 hours of hospitalization at the study hospitals. For confirmed-melioidosis cases, patients who had a clinical specimen tested positive for B. pseudomallei by either culture or antigen-detection immunofluorescence microscopy were enrolled. The primary endpoints were 28-day and 90-day mortality. Principal findings: From November 2023 to October 2024, 627 patients were screened and 200 patients were enrolled (43 for suspected-melioidosis and 157 for confirmed-melioidosis). Five of 43 patients enrolled with suspected-melioidosis (12%) were subsequently diagnosed with culture-confirmed melioidosis since enrollment. 28-day and 90-day mortality were 14% (6/43) and 23% (10/43) in suspected-melioidosis patients, respectively; and 25% (39/157) and 36% (57/157) in confirmed-melioidosis patients, respectively. In multivariable Cox regression models, higher Sequential Organ Failure Assessment (SOFA) score at enrollment and intensive care unit (ICU) admission on the day of enrollment were strongly associated with mortality outcomes. Admission to SRH and longer duration of symptoms prior to enrollment were independently associated with survival outcomes. Conclusions: Future clinical trials aiming to reduce mortality in patients with suspected or confirmed melioidosis should consider stratification based on the severity of organ dysfunction at enrollment. Differences in mortality between study sites may reflect residual confounding and should be carefully considered in sample size calculations. Author summary: Melioidosis is a frequently fatal infection caused by the soil bacterium Burkholderia pseudomallei and is a major cause of sepsis in Southeast Asia. Because the bacterium is intrinsically resistant to many commonly used antibiotics and melioidosis is difficult to diagnose using clinical presentation alone, clinicians often initiate empirical antibiotic therapy effective against B. pseudomallei once the disease is suspected. Treatment is continued for a complete course once the diagnosis is confirmed by bacterial culture results. However, patients treated for “suspected” melioidosis are seldom studied, and the factors associated with mortality in melioidosis remain poorly defined, in part because few studies have spanned more than one country. We prospectively followed 200 adults admitted with suspected or confirmed melioidosis at three hospitals in Laos and Thailand for 90 days. 90-day mortality was high in patients with both suspected and confirmed melioidosis. Factors associated with mortality included the severity of organ failure and intensive-care admission at enrollment, whereas a longer duration of symptoms before enrollment and care at one study hospital were associated with survival. These findings suggest that future trials aiming to reduce melioidosis mortality should account for organ-failure severity and between-hospital differences when designing patient selection and calculating sample size.
SN - 1935-2735
ER -