Prevalence of Cryptosporidium oocysts and Giardia cysts in the drinking water supply in Japan

Occurrences and genotypes of Cryptosporidium oocysts in river network of southern-eastern China

“…Nevertheless, the concentrations of Cryptosporidium oocysts were in a relatively low level for the three campaigns with 20/37 (54.1%) positive samples having less than five oocysts in 10-L samples. These concentration levels of the parasites were in accordance with some previous studies in China (Cai et al 2007;Sun et al 2007) and Japan (Hashimoto et al 2002), but much lower than other studies (Srisuphanunt et al 2010;Castro-Hermida et al 2008). …”

“…High prevalence of Cryptosporidium oocysts in river water was also obtained in some other studies conducted in the United States (99%) (Keeley and Faulkner 2008), Spain (63.5%) (Carmena et al 2007), Netherlands (100%) (Schets et al 2008), Brazil (100%) (Franco et al 2001), Taiwan (72.2%) (Hsu et al 1999), and Japan (100%) (Hashimoto et al 2002). According to our field investigation, animal breeding activities are extensive near the rivers which flow into the midstream section of the Beijing-Hangzhou Grand Canal (Fig.…”

“…The concentrated oocysts were separated from other particulate materials by flotation on Percoll-sucrose gradients, as described previously (Hashimoto et al 2002). Briefly, the particulate suspension (3 mL) was transferred to a 15-mL conical centrifuge tube and underlaid with approximately 5 mL of Percoll-sucrose solution (specific gravity, 1.10), using a capillary pipette.…”

Risk assessment of Giardia from a full scale MBR sewage treatment plant caused by membrane integrity failure

“…After filtration, the membrane filter was transferred to a fresh screw-capped conical 50-mL centrifuge tube and transported on ice to the laboratory for further processing within 72 hr (USEPA, 2005). The membrane filters were dissolved in acetone solutions to recover Giardia, as described previously (Hashimoto et al, 2002). The detection of Giardia was conducted according to previous studies (Hashimoto et al, 2002;Xiao et al, 2012).…”

“…The membrane filters were dissolved in acetone solutions to recover Giardia, as described previously (Hashimoto et al, 2002). The detection of Giardia was conducted according to previous studies (Hashimoto et al, 2002;Xiao et al, 2012). A detailed description of the microscopic detection method for Giardia is provided in Appendix A.…”