Short Report: Melioidosis as a Consequence of Sporting Activity

Abstract

In the tropical city of Darwin, Northern Territory, Australia, dry season soil sampling cultured Burkholderia pseudomallei from 7 (70%) of 10 sports fields. However, during the 23 years of the Darwin Prospective Melioidosis Study, only 5 (0.6%) of 785 melioidosis cases have been attributed to infection from sports fields. In one soccer player with cutaneous melioidosis, B. pseudomallei cultured from the player was identical by multilocus sequence typing and multilocus variable-number tandem repeat analysis with an isolate recovered from soil at the location on the sports field where he was injured. Melioidosis is uncommon in otherwise healthy sports persons in melioidosis-endemic regions but still needs consideration in persons with abrasion injuries that involve contact with soil. Athletes can be infected by pathogens through inoculation events caused by cuts and abrasions resulting from sporting activities. 1 A notable example is the methicillin-resistant Staphylococcus aureus outbreak in a professional American football team that was associated with turf-abrasion inocula- tion. 2 With the globalization of sporting competitions, the rate of returning athletes with diseases endemic to tropical regions is expected to increase, such as occurred with the Eco-challenge 2000 event in Malaysian Borneo, where leptospirosis developed in > 80 of the endurance athletes after contact with contami- nated water and soil. 3,4 Melioidosis is another disease that is endemic in tropical regions, potentially placing athletes at risk from inoculation events through broken skin and contact with contaminated soil or surface water. 5,6 In the early 1970s, Burkholderia pseudomallei, the causative bacterium of melioidosis was found in surface water samples of five sports fields in Singapore 7 after a potential sporting connec- tion in two of ten cases described from neighboring Malaysia. 8 In DarwininnorthernAustralia,B. pseudomalleilevels inthe upper soil layers increase during the wet season (October-April), and B. pseudomallei is often cultured from surface water. 9 The first use of molecular genotyping to link clinical isolates of B. pseudomallei to epidemiologically related environmental strains was published in 1994 and used ribotyping. 10 However, ribotyping has limited specificity in its ability to discriminate between closely related strains of B. pseudomallei. Subsequently, pulsed-field gel electrophoresis was shown to be superior to ribotyping and was used to link two separate clonal clusters of melioidosisinnorthernAustraliatocontaminationofthecommu- nitywatersupplieswithB.pseudomallei. 11,12 Multilocussequence typing (MLST) has more recently become the global standard for epidemiologic investigations of melioidosis, with > 1,000 B. pseudomallei sequence types (STs) identified worldwide. 13