[Occurrence of Giardia cysts and Cryptosporidium oocysts in swimming pools in the province of Palermo, Italy].

21 samples of waters of 7 swimming pools in the province of Palermo were investigated for the presence of Giardia cysts and Cryptosporidium oocysts. Some chemio-physical parameters (chlorine, temperature, turbidity and pH) were also evaluated as well as the presence of bacterial indicators of faecal (total coliforms, Escherichia coli and enterococci), mucocutaneous and environmental (Staphylococcus aureus and Pseudomonas aeruginosa) contamination. All samples were negative for bacterial indicators of faecal contamination; 3 were positive for the presence of coagulase-negative staphylococci, 1 was positive for Alcaligenes spp. and 2 for Pseudomonas aeruginosa. 8 samples proved to be positive for Giardia and 6 also for Cryptosporidium. All but one of them were coming from waters of 2 swimming pools of the same recreational center. In all samples the concentration of Giardia was substantially higher than that of Cryptosporidium. This study shows that the disinfection and filtering plants are not always suitable to ensure a good level of the quality of the waters of swimming pools and suggests that should be necessary to check them also for the presence of protozoa like Giardia and Cryptosporidium, which may be responsible for gastroenteritis.