Melioidosis and Leptospirosis

Melioidosis

• Gram-negative Burkholderia pseudomallei
• Soil saprophyte seen in tropical Australia that live in soil in dry season and are released in wet season +- airborne
• Diabetes, alcoholics, elderly, indigenous, CKD and chronic lung disease at high risk
• Transmission via skin (cuts, sores), inhalation or ingestion of contaminated water
• Pneumonia most commonly but bacteraemic spread can cause abscesses anywhere in body (especially spleen and prostate), septic arthritis, osteomyelitis and neurological disease
• Septic shock occurs in 20% and carries high mortality
• Unusually can develop sepsis after long period of subclinical infection and its potential for recurrence
• Localised cutaneous abscesses and ulcers are common

Melioidosis

• Serological tests are of limited utility
• Cultures of body fluids (Ashdown’s selective medium) can confirm cases
• CT abdo/pelvis recommended in all confirmed cases to identify abscesses
• Non-neurological
  • Meropenem 1g IV q8h for 14 days
• Neurological
  • Meropenem 2g IV TDS for 4 weeks
• If CNS/osteomyelitis/septic arthritis/genitourinary and skin/soft tissue:
  • Add Bactrim 320/1600mg BD + Folic acid 5mg daily for eradication

Leptosporosis

• High prevalence in tropical regions
• Transmission via urine of infected animals (specifically mice, rats)
• Enter body through skin, circulate by blood and invade kidney, lungs and liver
• Spiraemic phase of non-specific flu-like illness with conjunctivitis +- jaundice, hepatosplenomegaly
• Immune phase follows with renal, hepatic failure, aseptic meningitis and pulmonary haemorrhage
• Diagnosis by serology (often need convalescent sample to confirm)
• PCR also available
• Cultures can take weeks to come positive

Leptospirosis

• Treatment
• Mild cases may not require antibiotics
• If suspected clinically
  • Doxycycline 100mg PO BD for 7 days
• If severe
  • Benzylpenicillin 1.2g q6h for 7 days or Ceftriaxone

Last Updated on October 2, 2020 by Andrew Crofton