An Italian Study on Cryptosporidium and Giardia in Wastewater, Fresh Water and Treated Water

Abstract

Cryptosporidium oocysts and Giardia cysts has been isolated from waters worldwide. In Italy, studies on these parasites in the environment are still limited due to absence of epidemiological evidence and difficulty of adequate methodologies of sampling and analysis. The new Drinking Water Directive 98/83/CE states that Cryptosporidium has to be determined in water intended for human consumption if Clostridium perfringens is detected. This investigation contributes to the knowledge of both Cryptosporidium and Giardia occurrences in Italian aquatic environments through a two-year monitoring program. In addition, indicator bacteria and Clostridium perfringens were monitored in sewage, surface waters, drinking water, and swimming pools and possible correlations were calculated among all the selected parameters. Cysts and oocysts were detected in sewage and surface water and Giardia numbers always prevailed over Cryptosporidium. The parasites were not detected in drinking water, while a positive sample was obtained from the analysis of swimming pools. Pearson's correlation coefficients evidenced a reciprocal correlation between both the protozoa and the Enterococci counts.

A Preliminary Assessment of the Occurrence of Cryptosporidium and Giardia in the School Swimming Pool Water in Dubai, United Arab Emirates

“…But unlike school B, both samples from school E were found positive for the presence of Cryptosporidium oocysts and Giardia cysts .In this case, the source of contamination is more likely to be birds because birds' fecal remaining was observed on the ground that surrounded the swimming pool. This result correlates with the results of another study [7]. This result indicates that shading the swimming pools or having indoor swimming pools might decrease the risk of outdoor contamination with Cryptosporidium oocysts and Giardia cysts.…”

“…One of the significant observations which could be related to the variability of the results between the different swimming pools is due to the type of the swimming pools. A study in Italy indicated that outdoor swimming pools tend to be more contaminated with Cryptosporidium oocysts and Giardia cysts [7]. In addition to the contamination of the swimming pool caused by humans, this study demonstrated that outdoor swimming pools were more contaminated with Cryptosporidium and Giardia compared to indoor swimming pools.…”

“…In addition to the contamination of the swimming pool caused by humans, this study demonstrated that outdoor swimming pools were more contaminated with Cryptosporidium and Giardia compared to indoor swimming pools. In that case, birds, wide range of animals in addition to human hosts was stated as the primary sources of the swimming pool contamination by the parasites [7].…”

“…For instance, in the United States the exposure to contaminated recreational water venues including swimming pools resulted in more than 18,500 illnesses and about 24 deaths from 1995-2004 [6]. In the past, bacteria were considered the major source of waterborne infections, but according to several studies, parasites have replaced bacterial pathogens and became the primary cause of waterborne diseases [7]. In particular, in the last decade several studies specifically in the United States, Canada, Australia and the United Kingdom stated that parasites such as Cryptosporidium and Giardia became a major source of waterborne illnesses including gastroenteritis [8].…”

“…A number of studies stated that several risk factors can increase the frequency of cryptosporidiosis and giardiasis associated with the swimming pools. For instance, risk factors including age, frequency of swimming and duration spent in a swimming pool as well as the type of swimming pool were found to have a significant role in increasing or reducing the incidences of both infections [3], [4], [7].…”