Melioidosis

Melioidosis is the disease caused by Burkholderia pseudomallei, a Gram-negative environmental bacterium ^[2]. It is described as endemic in tropical areas, especially Southeast Asia and northern Australia, and is also associated with soil and water in tropical and subtropical regions globally ^[1][2][3]. The organism is noted in the literature as a tier 1 select agent, reflecting its recognized public-health and biodefense relevance ^[3].

Clinical presentations range from acute septicaemia to chronic infection, with reported syndromes including acute bacteremic pneumonia, disseminated visceral abscesses, and localized infections ^[2][3]. The majority of patients present with sepsis, although manifestations and severity vary by route of entry, host immune function, and bacterial strain and load ^[2]. The infection is described as life-threatening, and delayed recognition and laboratory diagnosis are associated with poor outcomes ^[2]. The organism’s intracellular survival and immune evasion are noted as contributors to persistence and disease expression ^[2][3].

Melioidosis is reported from tropical and subtropical regions worldwide, with endemicity emphasized in Southeast Asia and northern Australia ^[1][2][3]. Review sources state that the disease remains vastly under-reported and that modelled estimates place the global burden at up to about 165,000 cases and 89,000 deaths per year, with one review estimating approximately 89,000 deaths annually ^[1][2][3]. Increased case numbers have been associated with high rainfall, severe weather events, and environmental disturbance, and climate change is anticipated to increase cases in some regions ^[1][3]. Genomic epidemiological investigations have also confirmed endemicity in newly recognized regions, including the southern United States ^[1].

Transmission occurs through environmental exposure to B. pseudomallei, with route-specific acquisition described as direct inoculation, inhalation, or ingestion ^[1][3]. Source material also notes entry through skin penetration and highlights soil and water as the organism’s environmental association ^[1][2]. No further source-backed detail on person-to-person spread is available in the provided snippets.

Source-backed risk groups include people with diabetes mellitus, and the literature also identifies male sex, alcohol abuse, immunosuppression, and socioeconomic disadvantage as associated factors ^[1][2][3]. Diabetes is described as a major risk factor and is specifically highlighted as potentially increasing future fatalities in the context of the global diabetes pandemic ^[2]. No additional high-risk group detail is supported beyond these associations in the provided sources.

The provided sources identify preventive measures as an area of active review and note ongoing vaccine development, including vaccine candidates ready for phase I clinical trials ^[1][3]. Because the snippets do not specify a validated prevention schedule or a particular protective regimen, source-backed detail on exact preventive guidance is not yet available. Public-health interpretation should therefore focus on environmental exposure awareness and the documented links with rainfall, environmental disturbance, and endemic soil-water settings ^[1][3].

In surveillance, melioidosis should be read as an environmentally acquired bacterial infection with geography that extends beyond historically emphasized endemic areas ^[1][3]. Case counts may rise after rainfall or environmental disruption, and under-reporting is a major concern in global burden estimates ^[1][3]. The disease is also relevant where severe sepsis, pneumonia, or deep abscess syndromes occur in settings with compatible exposure history, particularly among populations with diabetes or other immunosuppressing conditions ^[2][3].

1. 1 Meumann EM et al. Burkholderia pseudomallei and melioidosis. Nat Rev Microbiol. 2024 Mar. PMID: 37794173. doi: 10.1038/s41579-023-00972-5. PubMed: https://pubmed.ncbi.nlm.nih.gov/37794173/
2. 2 Wiersinga WJ et al. Melioidosis. Nat Rev Dis Primers. 2018 Feb 1. PMID: 29388572. doi: 10.1038/nrdp.2017.107. PubMed: https://pubmed.ncbi.nlm.nih.gov/29388572/
3. 3 Gassiep I et al. Human Melioidosis. Clin Microbiol Rev. 2020 Mar 18. PMID: 32161067. doi: 10.1128/CMR.00006-19. PubMed: https://pubmed.ncbi.nlm.nih.gov/32161067/
4. 4 Melioidosis. Tropical Infectious Diseases: Principles, Pathogens and Practice. 2011. doi: 10.1016/b978-0-7020-3935-5.00033-1. DOI: https://doi.org/10.1016/b978-0-7020-3935-5.00033-1
5. 5 Melioidosis. Journal of The Academy of Clinical Microbiologists. 2013. doi: 10.4103/0972-1282.116094. DOI: https://doi.org/10.4103/0972-1282.116094
6. 6 Melioidosis. Manson's Tropical Diseases. 2009. doi: 10.1016/b978-1-4160-4470-3.50070-7. DOI: https://doi.org/10.1016/b978-1-4160-4470-3.50070-7

ICD-10

ICD-11

Total cases

1K

Peak month

2024-08

Coverage

5 reporting countries · 2022-01-01 → 2026-06-20