Tom Boyles, Marc Mendelson - Department of Infectious Diseases and HIV Medicine, Division of Medicine, UCT.
27 year old man from the Philippines presented to a peripheral hospital in Cape Town with a 1 week history of fever, headache, chills and euritic chest pain. He also had a cough productive of blood stained sputum. Six weeks earlier he had left his job as a rice farmer in Northern Philippines and flown to Montevideo where he immediately boarded a cargo ship bound for Cape Town. He remained fit and well for the first 5 weeks of the journey while working on the ship and only became sick 1 week prior to arrival. He had no other previous travel history and no previous illnesses of note. Initial CXR (figure 1) showed some ill-defined opacification of the lung fields bilaterally with a pleural effusion and he was treated with ceftriaxone and clarithromycin for community acquired pneumonia. Four sets of blood cultures taken after initiation of antibiotics were subsequently negative.
Symptoms did not improve and he was transferred to our institution after 4 days. At this time he was unwell with temperature 38.5 C, bibasal crepitations, a left pleural rub and a 5cm hepatomegaly. Investigations showed total WCC 11, Hb 11, plt 39, bil 312, ALT 226, ALP 116. HIV serology was negative, sputum smear microscopy with ZN stain was negative on 2 occasions. The pleural aspirate was neutrophil predominant (60%) with a total protein of 44, LDH 1057, ADA 16,6 and both bacterial and mycobacterial cultures were negative.
At this point a clinical diagnosis of melioidosis was made and imipenem 500mg 6hrly was initiated. After 4 days the fever had settled and the patient was feeling better and his blood parameters began to normalise. He continued to improve and after 14 days of imipenem he was discharged with a 3 month course of co-trimoxazole.
Question 1: Which organism causes melioidosis, what is its geographical distribution and route of transmission?Continue to Answer 1