Description of two fatal cases of melioidosis in Mexican children with acute pneumonia: case report

Abstract

Background: Melioidosis is an infectious disease caused by Burkholderia pseudomallei. In Mexico, the disease is rarely diagnosed in humans and there is no evidence of simultaneous environmental isolation of the pathogen. Here, we describe clinical profiles of fatal cases of melioidosis in two children, in a region without history of that disease.

Case presentation: About 48 h before onset of symptoms, patients swam in a natural body of water, and thereafter they rapidly developed fatal septicemic illness. Upon necropsy, samples from liver, spleen, lung, cerebrospinal fluid, and bronchial aspirate tissues contained Burkholderia pseudomallei. Environmental samples collected from the locations where the children swam also contained B. pseudomallei. All the clinical and environmental strains showed the same BOX-PCR pattern, suggesting that infection originated from the area where the patients were swimming.

Conclusions: The identification of B. pseudomallei confirmed that melioidosis disease exists in Sonora, Mexico. The presence of B. pseudomallei in the environment may suggest endemicity of the pathogen in the region. This study highlights the importance of strengthening laboratory capacity to prevent and control future melioidosis cases.

Keywords: Burkholderia pseudomallei; Case report; Fatal outcome; Melioidosis.

Fig. 1

Chest X-ray upon hospital admission of children infected with melioidosis. a, 12-year old male patient showing basal radio-opacities in both lungs. b, 16-year old female patient showing disseminated bilateral micronodular infiltrate in both lungs. Both patients received the antibiotics ceftazidime (2 g IV e/8 h), vancomycin (10 mg/Kg IV, e/6 h) and fluconazole (10 mg/Kg IV, e/24 h)

Fig. 2

Macroscopic and microscopic images of lungs and spleen from a fatal case of melioidosis. a, macroscopic aspect of the lungs with several abscesses. b, microscopic image of the lung showing the multiple abscesses from the male patient. c, macroscopic aspect of the spleen with splenomegaly and many abscesses. d, microscopic image of the spleen with destruction of the splenic parenchyma in the central territory of the cavity. The arrows indicate the abscesses

Fig. 3

Phylogenetic relationship among Burkholderia pseudomallei group species based in the analysis of 16S rRNA gene sequence by maximum likelihood under the model GTR + G. In bold are the strains analyzed in this study. In parenthesis are the accession number in the GenBank database. The bar means the expected differences among sequences

Fig. 4

BOX-PCR from Burkholderia pseudomallei strains. Lanes: 1, 1 Kb molecular marker; 2, HLCR2; 3, HLCR3; 4, HLCR7; 5, SoA-9; 6, S2Se-3.1; 7, Negative control; 8, Positive control Burkholderia contaminans UNL15–3