Melioidosis: A Correlation of the Radiologic and Pathologic Findings

Abstract

Melioidosis is a disease caused by a motile, pleomorphic, Gram-negative bacillus, Pseudomonas pseudomallei. The clinical manifestations were first described in 1912 by Whitmore and Krishnaswami (17). Clinically as well as bacteriologically related to glanders, melioidosis is characterized by a fulminating septicemia with extreme prostration and a high mortality rate. Over 300 cases of this disease have been reported, 2 in persons who had never been outside the United States (2, 11). The 7 pathologically proved cases in this series were in United States servicemen in South Vietnam. The clinical manifestations, pathologic findings, and radiologic correlation will be considered in an attempt to establish an approach for early diagnosis. All the 7 cases in our experience occurred in individuals who were in excellent health prior to their illness. They had been engaged in widely varied activities; therefore, from an initial epidemiologic search, the only common factor is general location. Six of the 7 patients presented with a three-to-five-day history of chills, fever, malaise, fatigue, and cough productive of small quantities of grayish-white or yellow-green sputum. On physical examination the patients were acutely ill with a fever of 102 to 104° F. Râles and rhonchi were usually heard on auscultation. The initial chest films showed 2 separate patterns. The more common radiographic pattern and, in our experience, the one most suggestive of melioidosis was that of irregular, nodular densities of 4–10 mm in diameter disseminated in the lung (Fig. 1). These had indistinct borders and seemed to enlarge, coalesce, or cavitate as the disease progressed. Less common was the pattern of unilateral irregular mottled densities with confluence and consolidation involving single or multiple lobes (Figs. 2 and 3). In our 7 cases there was no evidence of pleural effusion, and in only 2 was there slight pleural reaction. Mediastinal widening was not seen, and enlarged hilar nodes were encountered in only 1 instance (Fig. 4). Of our 7 cases of melioidosis the first 5 were fatal. The last 2 patients survived and were asymptomatic at the time of this writing. Our first few cases were diagnosed at autopsy and were so rapid in their course that in later cases massive doses of multiple antibiotics were given. In all but 1 of the 5 fatal cases, there was a history of fever, chills, malaise, and cough of several days duration. This patient was admitted to the hospital because of a combat wound and was well except for his injury. After several days in the hospital a generalized pustular rash developed, which later formed multiple abscesses over the body. After approximately two weeks in the hospital, positive chest findings were noted on physical examination and the chest film revealed a pattern of diffuse irregular nodular densities.