Risk and control of waterborne cryptosporidiosis

Rose, Joan B.; Huffman, Debra E.; Gennaccaro, Angela

doi:10.1111/j.1574-6976.2002.tb00604.x

Cited by 125 publications

(36 citation statements)

References 76 publications

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“…These protozoans can be detected in several water sources including wastewaters, surface waters, spring waters, recreational waters, ground waters and drinking waters (Solo-Gabriele et al 1998;Franco et al 2001;Rose et al 2002;Hachich et al 2004;Briancesco & Bonadonna 2005;Ryu & Abbaszadegan 2008;Muchiri et al 2009). …”

mentioning

confidence: 99%

Detection of Giardia and Cryptosporidium cysts/oocysts in watersheds and drinking water sources in Brazil urban areas

Razzolini

Santos

Bastos

2009

Journal of Water and Health

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The protozoan parasites Giardia and Cryptosporidium have been described as important waterborne disease pathogens, and are associated with severe gastrointestinal illnesses.The objective of this paper was to investigate the presence of Giardia cysts and Cryptosporidium oocysts in samples from watershed catchments and treated water sources. A total of 25 water samples were collected and examined according to the US EPA-Method 1623, 2005, consisting of 12 from drinking water and 13 from raw water. Positive samples from raw water for Giardia cysts and Cryptosporidium oocysts were 46.1 and 7.6%, respectively. In finished water, positive samples were 41.7% for Giardia cysts and 25.0% for Cryptosporidium oocysts. Concentrations of Giardia cysts found in raw water samples ranged from "not detected" to 3.4 cysts/L, whereas concentrations of Cryptoporidium oocysts ranged from "not detected" to 0.1 oocysts/L. In finished water, Giardia concentrations ranged from "not detected" to 0.06 cysts/L, and Cryptosporidium, from "not detected" to 0.01 oocysts/L. Concentrations of Giardia cysts and Cryptosporidium oocysts were not high in the samples analyzed. Nevertheless, the results of this study highlight the need to monitor these organisms in both raw and drinking water.

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mentioning

confidence: 99%

Detection of Giardia and Cryptosporidium cysts/oocysts in watersheds and drinking water sources in Brazil urban areas

Razzolini

Santos

Bastos

2009

Journal of Water and Health

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“…C. parvum is also of significant concern to farmers, as postmortem data indicate that the majority of calves who die at less than 1 month of age are infected with this parasite (2). Tap water is the most common risk factor for recorded human cases (3), since Cryptosporidium oocysts are robust and long-lived, have a low infectious dose, and are highly resistant to chlorination (4). The parasite is resistant to most commercial disinfectants, and while filtration can physically remove oocysts, this is not always available or completely effective.…”

mentioning

confidence: 99%

Silver Nanoparticles Decrease the Viability of Cryptosporidium parvum Oocysts

Cameron

Gaiser

Bhandari

et al. 2016

Appl Environ Microbiol

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dOocysts of the waterborne protozoan parasite Cryptosporidium parvum are highly resistant to chlorine disinfection. We show here that both silver nanoparticles (AgNPs) and silver ions significantly decrease oocyst viability, in a dose-dependent manner, between concentrations of 0.005 and 500 g/ml, as assessed by an excystation assay and the shell/sporozoite ratio. For percent excystation, the results are statistically significant for 500 g/ml of AgNPs, with reductions from 83% for the control to 33% with AgNPs. For Ag ions, the results were statistically significant at 500 and 5,000 g/ml, but the percent excystation values were reduced only to 66 and 62%, respectively, from 86% for the control. The sporozoite/shell ratio was affected to a greater extent following AgNP exposure, presumably because sporozoites are destroyed by interaction with NPs. We also demonstrated via hyperspectral imaging that there is a dual mode of interaction, with Ag ions entering the oocyst and destroying the sporozoites while AgNPs interact with the cell wall and, at high concentrations, are able to fully break the oocyst wall.

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“…In addition, as demonstrated in the present study, even the most heavily contaminated oysters did not contain more viable oocysts than the ID 50 value of a moderately virulent C. parvum isolate, that is, IOWA, ID 50 =190 oocysts (Messner et al 2001). Cryptosporidiosis has lifethreatening consequences in people with various immune deficiencies, and it is thought that in this population, a single oocyst can cause infection (Rose et al 2002). However, it is also believed that people with immunological impairments are usually more aware of the potential health hazards associated with consumption of raw food items, particularly molluscan shellfish, and are therefore more likely avoid this type of food (Rippey 1994).…”

Section: Discussionmentioning

confidence: 61%

Quantitative assessment of viable Cryptosporidium parvum load in commercial oysters (Crassostrea virginica) in the Chesapeake Bay

et al. 2006

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The epidemiological importance of increasing reports worldwide on Cryptosporidium contamination of oysters remains unknown in relation to foodborne cryptosporidiosis. Thirty market-size oysters (Crassostrea virginica), collected from each of 53 commercial harvesting sites in Chesapeake Bay, MD, were quantitatively tested in groups of six for Cryptosporidium sp. oocysts by immunofluorescent antibody (IFA). After IFA analysis, the samples were retrospectively retested for viable Cryptosporidium parvum oocysts by combined fluorescent in situ hybridization (FISH) and IFA. The mean cumulative numbers of Cryptosporidium sp. oocysts in six oysters (overall, 42.1+/-4.1) were significantly higher than in the numbers of viable C. parvum oocysts (overall, 28.0+/-2.9). Of 265 oyster groups, 221 (83.4%) contained viable C. parvum oocysts, and overall, from 10-32% (mean, 23%) of the total viable oocysts were identified in the hemolymph as distinct from gill washings. The amount of viable C. parvum oocysts was not related to oyster size or to the level of fecal coliforms at the sampling site. This study demonstrated that, although oysters are frequently contaminated with oocysts, the levels of viable oocysts may be too low to cause infection in healthy individuals. FISH assay for identification can be retrospectively applied to properly stored samples.

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Risk and control of waterborne cryptosporidiosis

Cited by 125 publications

References 76 publications

Detection of Giardia and Cryptosporidium cysts/oocysts in watersheds and drinking water sources in Brazil urban areas

Detection of Giardia and Cryptosporidium cysts/oocysts in watersheds and drinking water sources in Brazil urban areas

Silver Nanoparticles Decrease the Viability of Cryptosporidium parvum Oocysts

Quantitative assessment of viable Cryptosporidium parvum load in commercial oysters (Crassostrea virginica) in the Chesapeake Bay

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