Acute Systemic Melioidosis: Autopsy Findings in Four Patients

Abstract

Melioidosis is a disease caused by the Gram-negative bacillus Pseudomonas pseudomallei. It is endemic in Southeast Asia, but is being seen with increasing frequency in the United States as more military personnel return from Vietnam. We have recently autopsied four patients with relatively minor burns who died with the acute systemic form of melioidosis. The clinical course was that of a fulminating septicemia. Grossly visible lesions were present in three patients, whereas microscopic lesions were present in all. The lungs, liver, spleen, and bone marrow were characteristically involved. The morphogenesis of a t3rpical pulmonary lesion was traced. The grossly visible lesions had a zonal architecture. Necrotic centers were surrounded by degenerative histiocytes. Peripherally, there was a mixed infiltrate of neutrophils and viable histiocytes. The entire lesion was surrounded by a hemorrhagic border. The causative organism was easily seen, using modified Giemsa or Gram stains. Early treatment in one case appeared to sterilize the lesion.