Bacteraemic melioidosis pneumonia: impact on outcome, clinical and radiological features.

OBJECTIVES: Melioidosis is an endemic disease in South-east (SE) Asia and bacteraemia in melioidosis is associated with high mortality. We describe some clinical and radiological features of bacteraemic pneumonia due to Burkholderia pseudomallei as well as a comparison with bacteraemic patients without pneumonia.
METHODS: Patients with positive blood cultures for B. pseudomallei from October 1997 to November 2001 were included. Patients were grouped as 'Pneumonia' and 'Non-pneumonia' according to clinical and radiological features.
RESULTS: Eighteen (60%) out of total 30 patients were in the pneumonia group. There was no significant difference in age, WBC count, platelet counts and bilirubin levels between the groups. However the 'Pneumonia' group had higher incidences of hyponatraemia, acidosis, diabetes with poor control, renal impairment and shorter length of stay. Twelve (66%) of 18 patients in the pneumonia group required ICU admission compared to none in the non-pneumonia group; all required mechanical ventilation. Only 13/30 (43%) patients had initial empiric antibiotic therapy that is appropriate for melioidosis. The pneumonia group also had significantly higher mortality (13/18, 72%) rate than the non-pneumonia group (3/12, 25%, P=0.03). Chest radiographs were non-specific. 7/18 (38%) had unilobar involvement of the lung, mostly left sided; the rest had multilobar or bilateral involvement. Six (33%) had pleural effusion. No patient had cavitary lung disease. Visceral abscesses (spleen, liver and prostate) were also common in ultrasound and CT scans in both groups.
CONCLUSION: (1) Bacteraemic melioidosis with pneumonia carries high mortality with most patients dying early. (2) Radiological features of melioidosis pneumonia are non-specific. (3) Clinicians who treat patients from SE Asia need to be aware of this condition to institute early and appropriate antibiotic therapy.