[Microbiological aspects of pool water].

It is well known that there is an elevated risk of diffusion of pathogenic micro-organisms in swimming pools. Preventive measures aimed at protecting the health of swimmers are complex because of the variety of micro-organisms involved, the different ways in which these can be transmitted and the involvement of both aquatic and environmental factors. In industrialised countries, the circulation of many pathogens which were common in the past has progressively decreased in recent years; in contrast, infections caused by emerging pathogens such as Pseudomonas, atypical mycobacteria, Aeromonas, Legionella, Cryptosporidium, Norwalk virus, adenovirus and rotavirus have increased in frequency. Such infections affect not only the gastrointestinal tract but also other body sites, in particular the skin, conjunctiva, respiratory tract and auditory apparatus. Opportunistic pathogens capable of causing potentially serious infections in debilitated and immunocompromised subjects may also be involved. It is clearly necessary, therefore, that preventive interventions and effective monitoring programs, regarding both pool water and environmental quality, be implemented in all swimming facilities.