Haemophagocytic lymphohistiocytosis due to Burkholderia pseudomallei in a primigravida

INTRODUCTION. Melioidosis is caused by Burkholderia pseudomallei, a Gram-negative, saprophytic bacillus, commonly found in soil or contaminated water. As infection with this bacterium produces a wide variety of clinical manifestations the organism is aptly called the ‘great mimicker’. Even though it is non-fastidious and an easily cultivable organism, it can be misidentified in automated identification systems. CASE REPORT. A 24-year-old primigravida presented with complaints of fever and myalgia of 45 days’ duration. She was diagnosed to have haemophagocytic lymphohistiocytosis (HLH) based on clinical and laboratory parameters. Blood and bone marrow culture sent to the microbiology laboratory grew non-fermenting Gram-negative bacilli which were misidentified as Burkholderia cepacia by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) technology. It was subsequently identified as B. pseudomallei by 16S rRNA gene sequencing. The patient was commenced on intensive phase therapy with intravenous ceftazidime for 2 weeks, followed by maintenance therapy with oral trimethoprim and sulfamethoxazole for 3 months. In view of HLH, she was treated with intravenous dexamethasone for 2 weeks which was later switched to oral dexamethasone for a period of 6 weeks. She responded well to the treatment, but had to undergo medical termination of her pregnancy as there was severe intrauterine growth restriction of the fetus. CONCLUSION. Prognosis of melioidosis is excellent if early diagnosis and appropriate antibiotic treatment is provided. In this era of automation, it is important to determine if the suspected pathogen is listed in the database of the automated identification system.