Fungal and parasitic contamination of indoor public swimming pools in Arak, Iran.

Background: Swimming is a popular exercise for different types of people at different ages. Public swimming pools are places where fungal infections can be easily transferred. The purpose of this study is to evaluate the quality of mycological, parasitological, and physicochemical parameters of swimming pools of Arak city.

Methods: This cross-sectional study was done for 12 months from April 2013 to March 2014 in six indoor active swimming pools of Arak city (A, B, C, D, E, and F). Samples were collected in four seasons, two times/season; each time, two samples were obtained from six specified locations (shallow level pool, deep level pool, dressing rooms, showers, margin of pool walls, and foot-washing sink) from each pool with a total of 576 samples. Physicochemical parameters including water temperature, pH, turbidity, and the residual chlorine were measured on-site. In order to isolate and detect the fungal agents, special filters and culture Sabouraud's dextrose agar, chloramphenicol, and mycosel agar media were applied. Furthermore, non-nutrient agar medium enriched with Escherichia coli was used to detect and to separate the eggs of the worms, cysts, and parasitic protozoa from centrifuges of samples. In order to investigate their sediment, optical microscope and culture media were used.

Results: We found that 456 (79.1%) samples were positive regarding the fungal elements, and 516 fungal species were isolated. The most common isolates were saprophytic species (8.74%), yeast species (25%), and dermatophyte species (2.5%). The most contaminated surfaces were foot-washing sinks and showers. In this study, Acanthamoeba parasites were isolated from one pool only. All the investigated physicochemical parameters of pool water except for the temperature were found to be in the standard range.

Conclusions: Existence of saprophytic fungi and yeast in pools' water is plausible to be considered as an indicator of water resistance to the detergent agents. This high degree of contamination is due to the huge number of visitors, the complexity of construction, the choice of materials, and the long opening hours. Isolation of dermatophytes and Acanthamoeba parasite from the pools' area and foot-washing sink reveals the important role of the public swimming pools in disease transmission.