CONTAMINATION OF HAND WASH DETERGENT LINKED TO OCCUPATIONALLY ACQUIRED MELIOIDOSIS DANIEL GAL, MARK MAYO, HEIDI SMITH-VAUGHAN, PALLAVE DASARI, MELITA MCKINNON, SUSAN P. JACUPS, ANDREW I. URQUHART, MARILYN HASSELL, AND BART J. CURRIE Menzies School of Health Research, Darwin, Northern Territory, Australia; Charles Darwin University, Darwin, Northern Territory, Australia; Department of Health and Community Services, Darwin, Northern Territory, Australia; Royal Darwin Hospital, Darwin, Northern Territory, Australia; Northern Territory Clinical School, Flinders University of South Australia, Darwin, Northern Territory, Australia Abstract. Two mechanics working at a garage in tropical northern Australia simultaneously developed upper limb melioidosis ulcers. Both patients had Burkholderia pseudomallei of identical pulsed-field gel electrophoresis (PFGE) type (Spe I). Environmental sampling identified B. pseudomallei in a container of commercial hand wash detergent as the likely source of infection, although there were multiple isolates of different PFGE types to the clinical isolates. INTRODUCTION Melioidosis is the disease manifested by infection with the gram-negative bacillus Burkholderia pseudomallei. It is a soil and water bacterium endemic in both southeast Asia and northern Australia, 1–3 and is increasingly identified outside these regions. 4 Melioidosis occurs in both animals 5 and hu- mans. 6,7 In the tropical “Top End” of the Northern Territory of Australia, melioidosis is the most common cause of fatal community-acquired bacteremic pneumonia. 6,8 Melioidosis is most commonly observed during the monsoonal wet season, 8–11 with incidences usually peaking after heavy rainfall. 10,12 The majority of fatal cases have one or more risk factors, most importantly diabetes, but also alcoholism, chronic renal dis- ease, chronic lung disease, and malignancy or immunosup- pressive therapy. 8,10 Occupations with frequent exposure to soil and surface water have also been implicated as an impor- tant risk factor for acquiring melioidosis. 10,12,13 For example, agricultural occupations primarily in rice farming and animal husbandry present a significant risk. 10,14,15 We describe here two cases of melioidosis that were associated with unusual occupational exposure. CASE REPORTS Two men, 43 and 50 years old, respectively, simultaneously developed ulcerated upper limb skin lesions following a pe- riod of monsoonal rains. The skin lesions persisted for six weeks before one of the individuals sought treatment for other symptoms of melioidosis. They were both vehicle me- chanics in a remote town garage that lies within the endemic region for melioidosis in the Top End of the Northern Ter- ritory. The 43-year-old patient presented to Royal Darwin Hospi- tal after 4–5 days of fever and a six-week-old non-healing lesion on the right hand. The patient also had type 2 diabetes mellitus. Clinical examination identified large right epitro- chlear and axillary lymphadenopathy. Swabs from the hand lesion and purulent fluid drained from axillary lymphadenitis both grew B. pseudomallei. Blood cultures were negative and a computed tomography (CT) abdominal scan identified sev- eral small hypodensities in the spleen suggesting splenic ab- scesses. Melioidosis serology using an indirect hemagglutina- tion assay (IHA) showed a titer of 1:640. He was treated with open drainage of the axillary lymphadenitis, intravenous ceftazidime, and oral trimethoprim/sulfamethoxazole. After four days, the patient was afebrile and the right hand lesion had healed. The lymphadenitis resolved after two weeks of intravenous ceftazidime and he subsequently completed an additional three months of oral trimethoprim/sulfa- methoxazole. A repeat CT scan showed that the splenic le- sions had completely resolved. The 50-year-old patient was sent to Royal Darwin Hospital following the diagnosis of melioidosis in his co-worker. He had a similar six-week-old non-healing skin lesion on his right forearm (Figure 1). Following the onset of the lesion, which was initially purulent, the patient had lethargy and fever but after two weeks the symptoms spontaneously resolved. His only medical risk factor for melioidosis was an estimated av- erage daily alcohol consumption of 60 grams. At admission, the patient was afebrile, with the only abnormalities being the 1-cm diameter forearm abscess and enlarged right epitro- chlear lymph nodes with overlying erythema. The skin lesion cultured B. pseudomallei, blood cultures were negative, and IHA titer was 1:5,120. He was treated with two weeks of intravenous ceftazidime together with oral trimethoprim/ sulfamethoxazole, followed by three additional months of tri- methoprim/sulfamethoxazole. The skin lesion and lymphade- nopathy resolved in the first week of therapy. The hand wash detergent from the garage was selectively cultured for B. pseudomallei, in which approximately 2% of total detergent volume was diluted with sterile water and fil- tered through several 0.2-m filters (Millipore Corporation, Bedford, MA). Filters were cultured separately in Ashdown’s broth (Oxoid Australia, Melbourne, Victoria, Australia) fol- lowed by the culture of any broth biofilm on Ashdown’s agar (Oxoid Australia). All B. pseudomallei isolates cultured were confirmed biochemically using the MicroScan Walkaway (Dade Behring, Deerfield, CA). Bacterial typing was performed using standard pulsed-field gel electrophoresis (PFGE) protocols, 16,17 with the following modifications that we have found to give optimum reproduc- ibility and discrimination. The bacterial cultures were grown overnight (16 hours) in Todd-Hewitt broth (Oxoid Australia) and harvested. Bacterial pellets were resuspended to an op- tical density at 600 nm of 0.5 in resuspension buffer (10 mM Tris-Cl, pH 8.0, 20 mM NaCl, 100 mM EDTA). The bacterial suspension was then mixed (1:1) with molten 2% low melting point agarose (75% NuiSieve GTG and 25% Seakem Gold agarose; BioWhittaker Molecular Applications, Rockland, ME) and pipetted into PFGE plug molds (Bio-Rad Labora- Am. J. Trop. Med. Hyg., 71(3), 2004, pp. 360–362 Copyright © 2004 by The American Society of Tropical Medicine and Hygiene 360