Prevalence of mycobacteria in a swimming pool environment

A study was performed to evaluate the prevalence of non-tubercular mycobact eria in swimming pool environments. The bacteria in question were found in 88.2% of pool water samples. The most frequent species were Mycobacterium g ordonae (73.5% of samples; range 1-840 cfu 100 ml(- 1)), M. chelonei (38.2% 2-360 cfu 100 ml(- 1)) and M. fortuitum (35.3% 2-250 cfu 100 ml(- 1)). The same species were also recovered from the water at the different phases of the treatment cycle, with relative percentages similar to those of the poo l water. Shower floors and pool edges also presented high concentrations of the mycobacteria (100% of samples) and M. marinum was isolated from the su rfaces of pool edges on two occasions (4.5% of samples). The swimming pool environment provides a suitable habitat for the survival and reproduction o f mycobacteria. Although mycobacteria are common in swimming pools, human m ycobacterial disease associated with their use is rare. Apart from superfic ial infections with M. marinum, the risk of more serious diseases in subjec ts with weakened immune systems should not be underestimated, given the wid espread presence of mycobacteria that are possible opportunistic pathogens and the direct contact bathers have with the water and aerosol.