Occurrence of Cryptosporidium and Giardia and the Relationship between Protozoa and Water Quality Indicators in Swimming Pools

Abstract

A total of 60 samples were collected from 35 swimming pools in Beijing, China, and the presence of Cryptosporidium and Giardia were investigated. The results showed that 16.7% and 15.0% of samples were positive for Cryptosporidium oocyst and Giardia cysts, respectively, with a mean concentration of 0.30 oocysts/10 L and 0.27 cysts/10 L. The oocysts and cysts were found to have higher rates of occurrence in August than in May. Genotyping confirmed the presence of Cryptosporidium hominis, C. parvum, and Giardia assemblages A and B, all of which were associated with human infections. The predominant species/assemblages were C. hominis and Giardia assemblage A. Analyses of the relationships between parasite oocysts/cysts, indicator bacteria, and physical-chemical parameters revealed that there was no correlation between 2 parasites and fecal bacterial indicators, whilst there was a significant correlation between protozoa and urea concentration, which indicates that urea concentration rather than fecal bacterial indicators might be an appropriate index for chlorine-resistant protozoa in swimming pools. This study provides useful information to improve the safety of swimming pool water and deduce the risk of protozoan infections.

A retrospective epidemiological analysis of human Cryptosporidium infection in China during the past three decades (1987-2018)

“…Cryptosporidium oocysts have been detected in various water bodies, which have caused over 524 waterborne outbreaks of cryptosporidiosis worldwide, and most of them are linked to drinking water and recreational water (particularly swimming pools) [16][17][18]. In China, although no waterborne outbreaks have been reported, Cryptosporidium oocysts have been detected in source and tap water [62][63][64] as well as swimming pools [65,66]. In a study conducted in Shanghai, well water as the drinking water supply had higher risk for human Cryptosporidium infection than tap water and hand pump water [S1 Table reference list-73].…”

Presence and molecular characterization of Cryptosporidium and Giardia in recreational lake water in Tianjin, China: a preliminary study

“…On the other hand, both protozoa have also been found in urban wastewater 16 , surface drinking water sources 17 – 19 and recently in treated recreational waters (i.e. swimming pool waters) 20 . However, little is known about their occurrence in untreated recreational water.…”

Educational technology for fatigue management related to antineoplastic chemotherapy

“…Due to being a natural reservoir for many pathogens, water could make the patient more susceptible to infections. The risk of disease or infection associated with swimming pools is mainly due to the fecal contamination of the water, which may be caused by feces released by swimmers or sources of contaminated water (20) , which was confirmed in a study that identified Cryptosporidium and Giardia in swimming pools, leading to the occurrence of outbreaks among swimmers (21) .…”