TABLE 3.

Clinical risk factors for melioidosis

Risk factorLevel of evidence
Diabetes mellitusBetween 37 and 60% of patients are diabetic, mainly type 2; case-control and population-based studies in Australia and Thailand give estimated relative risk of 5.9 to 13.1 (111, 114, 299, 415, 417)
Thalassaemiaα-Thalassemia trait common in Thailand (44%) but disease less common (8%); case-control studies in Thailand estimate relative risk of 10.2 (415, 417, 464)
AboriginalityPopulation-based study in Australia estimates relative risk of 2.7 to 8.1, assumed to relate to exposure to soil or water (111, 114, 299)
Male genderAll series in Australia, Thailand, Malaysia, and Singapore demonstrate male preponderance (114, 191, 299, 417)
Soil/water exposureRice farmers constitute 81% of patients in Thailand, relative risk in case-control study estimated at 3.3 (415, 417)
Renal diseasePatients with renal impairment or failure comprise 10% of Australian series (111) with relative risk of 3.2 (114); renal disease (renal failure and calculi) associated with increased risk of melioidosis (odds ratio, 2.9) (415, 417)
Excessive alcohol consumptionConflicting evidence; excessive alcohol use documented in 39% of Australian patients, with relative risk of 2.1 to 6.7 in case-control and population-based studies (111, 114, 299), less prevalent in Thai patients (12%) (417)
Kava useUse of Piper methysticum root documented in 8% of Australian series (111) but not associated with pneumonia in case-control study (98)
Chronic lung diseasePresent in 27% of Australian patients (111), with relative risk of 4.3 (114)
SplenectomyCase studies, often related to thalassemia (196, 334, 464)
Aplastic anaemia, febrile neutropeniaCase reports only (273, 417)
Chronic granulomatous diseaseTwo case reports (146, 422)
Mycobacterial diseaseCase reports of patients with infection with atypical mycobacteria, M. tuberculosis, or M. leprae may suggest common host susceptibility (56, 89, 362, 417)
Dengue hemorrhagic feverFive of 18 pediatric patients in Thailand (334)
NeutropaeniaCase report (189)
Renal transplantationCase report, patient also diabetic (224)
Systemic lupus erythematosis or steroid useCase reports, also associated with immunosuppressives (29, 95, 398, 417); steroid-containing herbal remedies documented in up to 10% of Thai patients (415)
Glucose-6-phosphatase deficiencyCase reports (417)
HemosiderosisCase reports (286, 363); one unreported case of pulmonary hemosiderosis secondary to mitral valve disease (B. Currie, unpublished data)
Cystic fibrosisReports from travelers to areas of endemicity (122, 198, 372, 458)
Porphyria cutanea tardaSubsequent to episode of melioidosis; likely to be an adverse event in response to medication (160)