Melioidosis in Italy: Symptoms, Causes & Treatment | aihealz
Infectious Disease
Melioidosis.Care & specialists in Italy
In Italy, melioidosis is managed by infectious diseases. Melioidosis is a tropical bacterial infection caused by Burkholderia pseudomallei, an environmental saprophyte found in soil and surface water across northern Australia, Southeast Asia, the Indian subcontinent, and increasingly recognized in Africa and the Americas. A 2016 modeling study estimated 165,000 human cases per year worldwide with 89,000 deaths, making it one of the most underdiagnosed killers in the tropics.
Burkholderia pseudomallei Gram stain showing characteristic bipolar safety-pin appearance. · Credit: CDC Public Health Image Library via Wikimedia Commons · Public Domain
Melioidosis (ICD-10: A24) is an infectious disease caused by Burkholderia pseudomallei, a Gram-negative bacillus that lives freely in soil and water across tropical and subtropical regions. The organism enters humans through skin inoculation, inhalation of aerosolized soil or water, or ingestion of contaminated water; person-to-person transmission is extremely rare. Once inside the host, B. pseudomallei is a facultative intracellular pathogen that can survive within macrophages and persist as a latent infection for years to decades before reactivation.
key facts
Prevalence
Estimated 165,000 human cases per year globally (Limmathurotsakul 2016 modeling)
Demographics
Male:female 2-3:1; over 50% of patients have diabetes
Avg. age
Peak incidence 40-60 years; rare in children except in northern Thailand
Global cases
165,000 cases per year with 89,000 deaths — predominantly Southeast Asia and northern Australia
Specialist
Infectious Disease
§ 02
How you might notice it
The key symptoms of Melioidosis are: Fever above 38°C with rigors, present in over 90% of acute cases and often the first sign., Cough with purulent or blood-streaked sputum, present in roughly half of patients and reflecting pulmonary involvement., Pleuritic chest pain with shortness of breath when consolidation or pleural effusion is established., Skin ulcer, abscess, or non-healing wound at a site of soil or water contact — often the only initial sign in localized disease., Joint pain and swelling, particularly in large weight-bearing joints (knee, hip), suggesting septic arthritis., Urinary frequency, dysuria, perineal pain, or acute urinary retention in prostatic abscess — a male-predominant complication., Right upper quadrant or left upper quadrant abdominal pain suggesting hepatic or splenic abscesses..
01Fever above 38°C with rigors, present in over 90% of acute cases and often the first sign.
02Cough with purulent or blood-streaked sputum, present in roughly half of patients and reflecting pulmonary involvement.
03Pleuritic chest pain with shortness of breath when consolidation or pleural effusion is established.
04Skin ulcer, abscess, or non-healing wound at a site of soil or water contact — often the only initial sign in localized disease.
05Joint pain and swelling, particularly in large weight-bearing joints (knee, hip), suggesting septic arthritis.
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How it’s diagnosed
B. pseudomallei colonies on Ashdown's selective medium — characteristic wrinkled colony morphology. · Credit: CDC Public Health Image Library · Public Domain
diagnosis
Diagnosis of melioidosis depends on awareness, microbiological isolation, and supportive imaging. In endemic regions, any patient with sepsis, pneumonia, or visceral abscess — especially with diabetes — should be tested for B. pseudomallei. Outside endemic areas, travel history is critical: melioidosis must be considered in returning travelers from northern Australia, Southeast Asia, the Indian subcontinent, and increasingly Africa and the Americas. The diagnostic gold standard is culture of B. pseudomallei from blood, sputum, urine, pus, or other normally sterile site using Ashdown's selective medium. The organism grows in 24-72 hours but can be initially misidentified by automated systems as Pseudomonas or another organism — laboratories in endemic regions are trained to recognize the characteristic wrinkled colony morphology and bipolar safety-pin Gram-stain appearance. The 2020 international consensus guidelines recommend immediate isolation precautions (BSL-3 in non-endemic regions) once melioidosis is suspected, due to laboratory-acquired infection risk. Imaging with chest X-ray and CT of the chest and abdomen identifies pulmonary consolidation, splenic and hepatic abscesses, and prostatic involvement. Splenic micro-abscesses on CT in an endemic-region patient with fever should suggest melioidosis until proven otherwise. Serologic tests including indirect hemagglutination assay support diagnosis in chronic or culture-negative cases but lack the specificity needed for acute diagnosis in endemic populations. Newer rapid lateral-flow antigen tests (Active Melioidosis Detect) are emerging for resource-limited settings.
Key tests
01
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Treatment & cost
medical treatments
✓Ceftazidime 2 g IV every 6 hours
✓Meropenem 1 g IV every 8 hours (2 g for CNS disease)
✓Trimethoprim-sulfamethoxazole 320/1600 mg twice daily for 3-6 months
✓Trimethoprim-sulfamethoxazole 320/1600 mg twice daily added during intensive phase
surgical options
Percutaneous abscess drainageSymptomatic improvement in 80-90% when combined with appropriate antibiotics.
Open surgical drainageSuccess comparable to percutaneous drainage when combined with antibiotics; higher morbidity.
Empyema decorticationResolution of empyema in over 85% with appropriate post-operative antibiotics.
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Causes & risk factors
known causes
Burkholderia pseudomallei environmental exposure
The bacterium lives freely in soil and surface water of endemic regions, particularly during the monsoon. Skin inoculation through cuts and abrasions, inhalation of aerosolized soil during storms, and ingestion of contaminated water are the principal routes of infection. The infectious dose by inhalation is very low.
Diabetes mellitus
Diabetes is present in over 50% of melioidosis patients in Thailand and Australia and increases risk roughly 12-fold. Impaired neutrophil and macrophage function in diabetes permits B. pseudomallei to survive intracellularly and disseminate.
Heavy alcohol use and chronic liver disease
Alcohol use disorder raises melioidosis risk 2-3 fold through impaired phagocytic function and increased iron availability. Cirrhotic patients are particularly susceptible to bacteremia and metastatic abscesses.
Chronic kidney disease
Patients on hemodialysis or with stage 4-5 chronic kidney disease have a 4-5 fold increased risk and worse outcomes due to immune dysfunction and frequent healthcare exposure with skin breaks.
Chronic lung disease and thalassemia
Cystic fibrosis, bronchiectasis, and thalassemia are independently associated with melioidosis. Iron overload from thalassemia enhances B. pseudomallei growth; chronic lung disease provides a substrate for chronic pulmonary colonization and reactivation.
Latency and reactivation
B. pseudomallei can persist intracellularly for years to decades before reactivating when host immunity wanes — well-documented in returning travelers and Vietnam-era veterans presenting with disease decades after exposure.
risk factors
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Living with it
01Wear waterproof boots and gloves during agricultural work, paddy field labor, or contact with soil and surface water in endemic regions, particularly during monsoon
02Cover skin cuts and abrasions with waterproof dressings before exposure to soil or surface water
03Drink only boiled, filtered, or commercially bottled water in endemic regions; avoid drinking from streams, puddles, or untreated wells
04Maintain tight glycemic control if diabetic — the single most important modifiable risk factor
05Avoid swimming in fresh surface water during monsoon flooding in northern Australia and Southeast Asia
recommended foods
•Balanced diet with adequate protein (1.0-1.2 g/kg/day) to support recovery from prolonged infection
•Diabetes-appropriate diet with controlled carbohydrate intake if diabetic
•Adequate hydration with safe, boiled or bottled water — 2 L daily
•Iron-rich foods only when needed clinically; avoid unnecessary iron supplementation during active infection
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When to seek help
why see an infectious disease
Melioidosis is a life-threatening infection that should be managed by an infectious disease specialist with hospital experience. In endemic regions, presumptive treatment with ceftazidime or meropenem is often started in emergency departments while awaiting culture confirmation. In non-endemic regions, an infectious disease consultation is essential because most clinicians have no direct experience and the organism is intrinsically resistant to many empirical antibiotic regimens.
Acute pulmonary melioidosisMost common presentation, accounting for approximately 50% of cases. Ranges from mild bronchitis to fulminant necrotizing pneumonia with cavitation. Often resembles tuberculosis radiologically.
Acute bacteremic septicemiaBloodstream infection with B. pseudomallei, present in roughly 50% of acute cases. Carries the highest mortality, particularly when accompanied by septic shock and multiorgan failure.
Skin and soft tissue melioidosisLocalized cutaneous infection, often at the site of inoculation. May progress to deep abscesses, osteomyelitis, or septic arthritis. Common after monsoon-related soil contact.
Visceral abscess formDisseminated abscesses in liver, spleen, prostate, kidneys, lymph nodes, or musculoskeletal tissue. Characteristic spleen abscesses on CT imaging strongly suggest melioidosis in endemic regions.
Neurological melioidosisRare but devastating brainstem encephalitis, cranial nerve palsies, or spinal cord syndromes. Particularly associated with strains carrying the BimA_Bm protein in northern Australia.
Chronic and latent melioidosisSymptoms persisting more than 2 months (chronic) or reactivation years to decades after exposure (latent). Latent disease re-emerging in elderly patients with new diabetes or immunosuppression is well documented.
Living with Melioidosis
Timeline
Symptom improvement typically begins within 3-7 days of starting effective intravenous therapy; persistent fever after 10-14 days suggests inadequate source control or deep undrained collection. The intensive intravenous phase lasts 10-14 days for uncomplicated disease and 4-8 weeks for complicated disease. The oral eradication phase runs 3 months for skin or pulmonary disease and 6 months for deep-seated, neurological, bone, or joint involvement. Surveillance for relapse continues to 12 months after the end of therapy.
Lifestyle
01Adhere to the full 3-6 month oral eradication course to prevent relapse — interrupting treatment is the leading cause of relapse
02Maintain HbA1c below 7% if diabetic to reduce relapse risk and overall mortality
03Reduce or stop alcohol consumption — independently raises mortality
04Use barrier precautions in occupational soil and water exposure even after recovery
05Inform any future medical team of your melioidosis history because reactivation can occur years to decades later
06Carry a medication card listing prior infection, regimen, and dates of treatment
Daily management
01Take eradication-phase trimethoprim-sulfamethoxazole exactly as prescribed, twice daily with food and adequate fluids
Choosing a doctor
Look for an infectious disease physician with tropical medicine training or experience in endemic regions. Care should be delivered in a hospital with intensive care, microbiology capable of identifying B. pseudomallei, and interventional radiology for abscess drainage. In non-endemic regions, telemedicine consultation with reference centers (Royal Darwin Hospital, Mahidol-Oxford Tropical Medicine Research Unit, CDC) is appropriate.
Melioidosis is a tropical bacterial infection caused by Burkholderia pseudomallei, a soil and water organism endemic in northern Australia, Southeast Asia, the Indian subcontinent, and increasingly Africa and the Americas. It causes pneumonia, abscesses, and septicemia and is responsible for an estimated 89,000 deaths per year worldwide. Most patients have diabetes as a predisposing condition.
How do you get melioidosis?▾▴
Melioidosis is acquired by skin contact with contaminated soil or water (through cuts and abrasions), by inhaling aerosolized soil during storms, or by drinking contaminated water. Person-to-person transmission is extremely rare. Most cases occur in agricultural workers, soldiers, and travelers in endemic tropical regions, particularly during monsoon.
Is melioidosis contagious?▾▴
Person-to-person transmission of melioidosis is very rare. Documented cases include occasional perinatal transmission and laboratory-acquired infection from handling cultures. Standard hospital isolation precautions are sufficient for patients; close contacts are not at increased risk in everyday life.
What are the symptoms of melioidosis?▾▴
Melioidosis can present in many ways. Most common are fever, cough, and pneumonia; many patients also develop skin abscesses, urinary symptoms, joint pain, or septic shock. Symptoms can develop over days to weeks. Diabetes, kidney disease, or recent travel to a tropical region with any of these symptoms should prompt testing for B. pseudomallei.
Where is melioidosis found?▾▴
Melioidosis is endemic across northern Australia, Thailand, Vietnam, Laos, Cambodia, Malaysia, Indonesia, India, Bangladesh, and parts of southern China. Recent reports document cases in sub-Saharan Africa, the Caribbean, Central America, and the southern United States. The organism lives in soil and surface water year-round but cases peak during the wet season.
How is melioidosis diagnosed?▾▴
Diagnosis is made by culturing Burkholderia pseudomallei from blood, sputum, urine, pus, or other clinical specimens. Specialized selective media (Ashdown's medium) help recovery. Serology supports diagnosis but lacks specificity in endemic regions. Imaging detects pneumonia, splenic and hepatic abscesses, and prostatic abscess that are characteristic of the disease.
How is melioidosis treated?▾▴
Treatment has two phases. The intensive phase uses intravenous ceftazidime or meropenem for 10-14 days or longer for severe disease. The eradication phase uses oral trimethoprim-sulfamethoxazole for 3-6 months to prevent relapse. Source control with abscess drainage and tight glycemic control are essential adjuncts. Standard antibiotics for ordinary pneumonia do not work against melioidosis.
What is the mortality rate of melioidosis?▾▴
Mortality depends on geography, presentation, and access to care. In northern Australia with intensive care, acute mortality is about 10%. In northeast Thailand, where presentation is often late, mortality is 30-40%. Septic shock at presentation carries 50% mortality or higher. Early diagnosis and prompt ceftazidime or meropenem therapy substantially improve survival.
Can melioidosis be cured?▾▴
Yes, with appropriate two-phase antibiotic treatment most patients can be cured. The intensive intravenous phase clears acute infection and the 3-6 month oral eradication phase prevents relapse. Relapse rates are 5-15% with full treatment and 25% or more with incomplete eradication. Long-term outcomes are good when underlying diabetes and other risks are also controlled.
Why does diabetes increase melioidosis risk?▾▴
Diabetes impairs neutrophil and macrophage function, both of which are critical for clearing B. pseudomallei. Hyperglycemia also raises tissue glucose available for bacterial growth. Diabetic patients have a 12-fold increased risk of melioidosis and worse outcomes. Tight glycemic control reduces both incidence and severity.
Is there a vaccine for melioidosis?▾▴
There is no licensed human vaccine for melioidosis as of 2026. Several candidate vaccines have shown promising results in animal models, and clinical trials are in progress. Prevention currently relies on reducing soil and water exposure, controlling diabetes, and rapidly diagnosing and treating any suspected case in endemic regions.
How long can melioidosis stay dormant?▾▴
Burkholderia pseudomallei can persist intracellularly in macrophages for years to decades. Documented cases of latent reactivation include Vietnam-era veterans presenting with melioidosis 30 years after exposure. Reactivation typically follows immune compromise — new diabetes, malignancy, or immunosuppressive therapy. Lifelong awareness of melioidosis history is important.
Can I get melioidosis in the United States?▾▴
Yes, although most US cases are travel-related, locally acquired cases have been documented in the Mississippi Gulf Coast and US territories such as Puerto Rico. The CDC issued an environmental health advisory in 2022 after locally acquired cases in Mississippi. Endemic areas may expand with climate change and increased monsoon-like rainfall in southern US states.
What antibiotics treat melioidosis?▾▴
First-line intensive-phase antibiotics are ceftazidime or meropenem given intravenously. Trimethoprim-sulfamethoxazole is the first-line oral eradication drug for 3-6 months. Amoxicillin-clavulanate is a second-line eradication option. B. pseudomallei is resistant to penicillins, first-generation cephalosporins, gentamicin, polymyxins, rifampin, and macrolides — these antibiotics will not work.
Why is melioidosis hard to diagnose?▾▴
Melioidosis presents in many ways — pneumonia, abscesses, sepsis, urinary tract infection — and can mimic tuberculosis, ordinary pneumonia, or cancer. Outside endemic regions, clinicians rarely consider it. Automated microbiology systems can misidentify the organism. Travel history and willingness to use selective culture media are essential for accurate diagnosis.
Can children get melioidosis?▾▴
Yes, although melioidosis is much less common in children than in adults. Suppurative parotitis (parotid gland abscess) is a characteristic pediatric presentation, particularly in northern Thailand and Cambodia. Pediatric melioidosis is generally less severe than adult disease and has lower mortality with appropriate treatment.
Does melioidosis come back after treatment?▾▴
Relapse occurs in 5-15% of patients within 1-2 years of completing full treatment. Risk is higher when the intensive or eradication phase is shortened, when adherence is poor, or when underlying conditions like diabetes are uncontrolled. Long-term follow-up at 3, 6, and 12 months after therapy is important to detect relapse early.
What is Whitmore disease?▾▴
Whitmore disease is an older name for melioidosis, named after Captain Alfred Whitmore, the British pathologist who described the disease in Rangoon in 1911. The current name melioidosis comes from Greek meaning resembling distemper. Both names refer to the same infection caused by Burkholderia pseudomallei.
How long is melioidosis treatment?▾▴
Total treatment lasts 3-7 months: 10-14 days of intravenous antibiotics (extended to 4-8 weeks for deep-seated or severe disease) followed by 3 months of oral trimethoprim-sulfamethoxazole for skin or lung disease, or 6 months for bone, joint, brain, or relapsed disease. Completing the full eradication phase is essential to prevent relapse.
06Urinary frequency, dysuria, perineal pain, or acute urinary retention in prostatic abscess — a male-predominant complication.
07Right upper quadrant or left upper quadrant abdominal pain suggesting hepatic or splenic abscesses.
08Confusion, focal neurologic deficits, or cranial nerve palsy when brainstem encephalitis is present (uncommon).
09Severe sepsis features including hypotension, oliguria, tachypnea, and altered mental status in the bacteremic form.
early warning signs
•Persistent fever lasting more than 3 days in a person living in or returning from northern Australia, Southeast Asia, or the Indian subcontinent — especially with diabetes
•A non-healing skin ulcer or abscess after agricultural work, paddy field exposure, or monsoon flooding
•Pneumonia that fails to respond to standard community-acquired antibiotics (amoxicillin-clavulanate, doxycycline, or macrolides) in an endemic area
•New visceral abscess on imaging (liver, spleen, prostate) in a diabetic patient from a tropical region
•Reactivation of unexplained febrile illness years after travel or residence in a known melioidosis-endemic area
● emergency signs
•Septic shock with hypotension, tachycardia, altered mental status, and reduced urine output — admit to ICU urgently and start broad-spectrum antibiotics covering B. pseudomallei
•Severe respiratory distress, hypoxia, or rapid radiographic progression of pneumonia — possible necrotizing pneumonia
•Acute neurologic deterioration, cranial nerve palsy, or coma — possible brainstem encephalitis requiring meropenem and adjunctive therapy
•Acute urinary retention with fever in a man from an endemic area — possible prostatic abscess requiring urgent imaging and drainage
•Rapidly enlarging abscess with surrounding cellulitis or necrosis — needs urgent drainage in addition to antibiotics
Blood culture with extended incubation
Detects bacteremia, which occurs in roughly 50% of acute melioidosis cases. Selective medium and trained laboratories improve sensitivity.
02
Sputum and abscess fluid cultureRecovery of B. pseudomallei from any site is diagnostic. Ashdown's selective medium improves yield from contaminated specimens.
03
Chest radiograph and CT chestIdentifies pneumonia, cavitation, pleural effusion, and mediastinal lymphadenopathy. Can resemble tuberculosis radiologically.
04
CT abdomen and pelvisDetects splenic and hepatic abscesses, prostatic abscess, and other deep collections. Micro-abscesses of the spleen and prostate are characteristic of melioidosis.
05
Indirect hemagglutination assay (IHA) and other serologySupports diagnosis in culture-negative or chronic cases. Less reliable in highly endemic populations due to background seropositivity from environmental exposure.
06
MRI brain or spinal cordIndicated when neurological signs suggest brainstem encephalitis or spinal cord involvement. May show characteristic patterns in pons and medulla.
Outlook
Mortality from melioidosis depends on geography, presentation, and access to care. In northern Australia with intensive care and protocolized therapy, acute mortality has fallen from 30% in the 1990s to approximately 10% today (Currie 2021 Darwin Prospective). In northeast Thailand, where many patients present late and access to ICU is limited, acute mortality remains 30-40%. Septic shock at presentation carries a mortality of 50% or more even with treatment. Neurological melioidosis has substantial residual deficits in survivors. Relapse occurs in 5-15% within 1-2 years of completing therapy when the full 3-6 month eradication phase is taken, and exceeds 25% when eradication therapy is shortened or omitted. Diabetes, alcohol use, and renal disease independently predict worse outcomes. Long-term survivors who complete therapy and control underlying conditions can expect a return to baseline health, though latent reactivation decades later is well-documented.
Diabetes mellitusmodifiable
Most important predisposition, present in 50-60% of cases in endemic regions. Confers a 12-fold increased risk and worse outcomes. Tight glycemic control reduces both incidence and mortality.
Heavy alcohol usemodifiable
Independently raises risk 2-3 fold. Particularly associated with severe pneumonia and bacteremia.
Chronic kidney disease and dialysismodifiable
Raises risk 4-5 fold. Dialysis patients have higher mortality and metastatic complication rates.
Thalassemia and other iron-overload statesnon-modifiable
Iron-rich macrophages favor intracellular survival of B. pseudomallei. Particularly relevant in Southeast Asia and the Mediterranean basin.
Male sexnon-modifiable
Men are 2-3 times more likely to develop melioidosis than women, partly due to occupational soil and water exposure and protective effects of estrogen on innate immunity.
Occupational soil and water exposureenvironmental
Rice farmers, agricultural workers, soldiers training in tropical environments, and construction workers face higher exposure. Wet-season risk is several-fold higher than dry-season risk.
Provides a substrate for chronic colonization and pulmonary disease. Cystic fibrosis is associated with chronic infection particularly in Australian patients.
Immunosuppressive therapy and malignancymodifiable
Corticosteroids, transplant immunosuppression, and hematological malignancy raise risk and increase the rate of disseminated disease.
•Vitamin D-sufficient foods or supplementation to maintain immune function
foods to avoid
•Heavy alcohol consumption — impairs immune function and raises relapse risk
•Untreated water from streams, ponds, wells, or puddles in endemic regions
•Unpasteurized milk or undercooked meat in resource-limited settings due to general infection risk
•Folk remedies that may interact with trimethoprim-sulfamethoxazole or doxycycline
•Excessive iron supplements without medical indication during active infection
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02Monitor for adverse effects (rash, jaundice, neutropenia, hyperkalemia) and report promptly to the infectious disease team
03Attend follow-up monthly during the eradication phase and at 3, 6, and 12 months after completion to monitor for relapse
04Check blood counts, renal function, and potassium periodically during long-course trimethoprim-sulfamethoxazole
05Maintain blood glucose targets, blood pressure control, and any underlying disease management
06Avoid further unprotected soil or water exposure in endemic regions
Exercise
During acute infection and the intensive antibiotic phase, rest and gradual mobilization as tolerated are appropriate. After hospital discharge and once the eradication phase is established, light to moderate exercise can resume as energy permits — typically over 4-12 weeks. Avoid renewed soil or water exposure in endemic regions until the full course is complete.
