Environment, Pathogens, and Host Interactions in Melioidosis

NCT07345910 | Not Yet Recruiting DMC

• 1 other identifier: MEL25001
• Study Type: observational
• Target: 2,400
• Locations: 3 countries
• Sites: 3

Brief Summary

This is a longitudinal, multicentre observational study conducted across three established microbiology units integrated within hospital and community health systems in Thailand, Lao PDR, and Cambodia. The hospital cohort will enroll approximately1,000 patients with positive melioidosis. Participants will be followed at six time points from admission through one year (post-discharge) to capture acute and recovery-phase outcomes, with clinical data collected on demographics, comorbidities, exposures, treatment, adherence, and outcomes. For each confirmed case, a healthy control will be recruited within two weeks and matched by age, sex, and village of residence. Controls with no symptoms or history of melioidosis will provide a single blood sample at enrolment and will be followed by telephone at 6 and 12 months. In addition to hospital-based surveillance, a high-risk community in northern Ubon Ratchathani-referred to as the Sandbox Village-will be intensively monitored to capture subclinical infections and to assess environmental factors influencing disease acquisition. This study is funded by the Wellcome Trust. The grant reference number is 323077/Z/24/Z

Conditions

Melioidosis

Outcome Measures

Primary Outcomes (5)

• Development of melioidosis following exposure, assessed among melioidosis cases

  365 days

• Development of melioidosis following exposure, assessed among healthy controls

  365 days

• Development of melioidosis following exposure, assessed among Sandbox Village residents

  3.5 years

• Mortality during the acute phase of infection among individuals with melioidosis (melioidosis cases).

  365 days

• Number of hospital readmissions following discharge among individuals with melioidosis (melioidosis cases).

  365 days

Secondary Outcomes (9)

• Changes in disease development following exposure associated with interactions between environmental modifications.

  3.5 years

• Changes in mortality during the acute phase of infection following exposure associated with interactions between environmental modifications.

  365 days

• Changes in hospital readmission following recovery associated with interactions between environmental modifications.

  365 days

• Changes in disease development following exposure associated with interactions between clinical management factors.

  365 days

• Changes in mortality during the acute phase of infection following exposure associated with interactions between clinical management factors.

  365 days

Study Arms (3)

Melioidosis patients

Patients confirmed to have melioidosis

Healthy controls

Healthy controls will be enrolled for each confirmed melioidosis case. A healthy control is defined as an individual with no current fever, no evidence of soft tissue infection, and no prior history of melioidosis. Controls will be recruited within approximately two weeks of case identification and will be matched to cases by age (±5 years), sex, and village of residence.

Sandbox village cohort

All residents of the Sandbox Village, a high-risk area for melioidosis, will be enrolled to monitor disease progression and to evaluate the impact of improved water sanitation.

Eligibility Criteria

• Age: 20 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Melioidosis patients: Patients confirmed to have melioidosis. Healthy controls: For each confirmed melioidosis case, a healthy control-defined as having no current fever, no evidence of soft tissue infection, and no prior history of melioidosis-will be recruited from satellite blood bank donors within approximately two weeks of case identification. Controls will be matched by age (±5 years), sex, and village of residence. Sandbox Village residents: All residents of the Sandbox Village, a high-risk area for melioidosis, will be enrolled to monitor disease progression and to evaluate the impact of improved water sanitation.

You may qualify if:

• Age ≥20 years
• Positive for Burkholderia pseudomallei from any clinical samples
• Resident of the study area for at least two years, including the follow-up period
• Willing to participate and give informed consent.
• Age ≥20 years
• Currently healthy as judged by study doctor
• Resident of the study area for at least two years, including the follow-up period
• Willing to participate and give informed consent.
• Age ≥20 years
• Resident of the study area for at least two years, including the follow-up period
• Willing to participate and give informed consent.

You may not qualify if:

• Current tuberculosis (TB) or TB treatment within the past six months
• Documented HIV infection or use of immunosuppressive therapy in the past 12 months
• History of melioidosis
• Significant acute illness
• Current fever or soft tissue infection
• N/A

Sponsors & Collaborators

• University of Oxford: lead

Study Sites (3)

Cambodia-Oxford Medical Research Unit (COMRU)

Siem Reap, Cambodia

Location

Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit (LOMWRU)

Vientiane, Laos

Location

Sunpasitthiprosong Hospital

Ubon Ratchathani, Thailand

Location

Biospecimen

Retention: SAMPLES WITH DNA

Blood samples will be collected for the following analyses: * DNA for genetic profiling * Serum for antibody measurement * Peripheral blood mononuclear cells (PBMCs) for immune cell analysis * HbA1c for assessment of blood glucose control * Plasma lactate for marker for disease severity

MeSH Terms

Conditions

Melioidosis

Condition Hierarchy (Ancestors)

Burkholderia Infections; Gram-Negative Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Infections

Study Officials

• Kamolchanok Claire Chewapreecha, PhD

  Mahidol Oxford Tropical Research Unit

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Kamolchanok Claire Chewapreecha, PhD

CONTACT

662 203 6333; claire@tropmedres.ac

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 7, 2026
• First Posted: January 16, 2026
• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): December 1, 2034
• Study Completion (Estimated): December 1, 2034
• Last Updated: January 16, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL

Locations

LA (1); TH (1); CA (1)