Epidemiology & Risk Factors

Etiology: Burkholderia pseudomallei (motile, Gram-negative, saprophytic bacillus).
Endemic regions: Southeast Asia (especially Thailand), Northern Australia, tropical/subtropical areas.
Transmission: Inoculation via skin abrasion w/ contaminated soil/water, inhalation (post-monsoon storms), or ingestion.
Key Risk Factors:
- Diabetes mellitus (single most important risk factor; present in > 50% of pts). c
- Chronic kidney disease (CKD).
- Excessive alcohol use / Cirrhosis.
- Chronic lung disease (COPD, bronchiectasis).
- Thalassemia.

Clinical Features

Termed “the great mimicker” due to variable disease spectrum.
Acute Pulmonary Infection (Most Common):
- High fever, productive cough, dyspnea, hemoptysis.
- Mimics severe community-acquired pneumonia (CAP) or Tuberculosis (TB).
Acute Septicemic / Disseminated Form:
- Rapid progression to septic shock, disorientation, multiorgan failure.
Visceral Abscesses:
- Multiple microabscesses in spleen, liver, or prostate. c
- Parotitis (classic high-yield presentation in pediatric pts in Southeast Asia).
Localized Cutaneous Infection:
- Non-healing skin ulcers, cellulitis, or localized nodular abscesses w/ regional lymphadenopathy.
Chronic Infection (> 2 months):
- Weight loss, night sweats, cavitary lung lesions (often misdiagnosed as TB).

Initial / Screening:
- Gram Stain: Gram-negative rods w/ characteristic “safety-pin” appearance (bipolar staining).
- CXR / CT Chest: Upper lobe consolidation, nodular infiltrates, or cavitary lesions.
- CT Abdomen/Pelvis: Multiple “honeycomb” or multiloculated abscesses in liver, spleen, or prostate.
Confirmatory / Gold Standard:
- Culture: Isolation of B. pseudomallei from blood, sputum, urine, or abscess aspirate (using Ashdown selective medium).
Key Labs:
- Leukocytosis w/ left shift, ↑ ESR/CRP, transaminitis if hepatic involvement.

Tuberculosis (TB):
- Diff by: Acid-fast stain (+), positive PPD/IGRA, slower growth on selective media. B. pseudomallei grows on standard blood agar / Ashdown agar.
Klebsiella pneumoniae Pneumonia:
- Diff by: Encapsulated Gram-negative rod (no bipolar safety-pin appearance), “currant jelly” sputum, absent characteristic visceral microabscesses.
Staphylococcus aureus Abscesses:
- Diff by: Gram-positive cocci in clusters, lacking specific tropical soil exposure.
Amoebic Liver Abscess (E. histolytica):
- Diff by: Typically single large “anchovy paste” liver lesion; B. pseudomallei causes multiple small microabscesses across organs (liver, spleen, prostate).

1. Emergency Stabilization / Acute Phase:
- Hemodynamic support (IVF, vasopressors) if in septic shock.
2. Intensive Initial Phase (IV Abx x 2–4 weeks minimum):
- First-line: IV Ceftazidime OR IV Meropenem / Imipenem (preferred for severe sepsis/septic shock).
- Goal: Prevent early mortality and reduce systemic bacterial load.
3. Eradication Phase (Oral Abx x 3–6 months):
- First-line: Oral Trimethoprim-sulfamethoxazole (TMP-SMX).
- Second-line / Alternative: Amoxicillin-clavulanate (if TMP-SMX allergy or intolerance).
- Goal: Prevent high risk of disease relapse.
4. Source Control:
- Percutaneous or surgical drainage of large prostatic or hepatic abscesses if clinically indicated.

Septic Shock / MODS: High mortality rate (> 40% in endemic septic cases).
Disease Relapse: Extremely common if eradication phase (TMP-SMX) is discontinued prematurely.
Spontaneous Abscess Rupture: Can lead to peritonitis or empyema.
Encephalomyelitis: Rare CNS extension leading to flaccid paralysis or cranial nerve deficits.

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