scholarly journals Corrigendum: Journal of Water and Health 10(1), 147–160: Total and infectious Cryptosporidium oocyst and total Giardia cyst concentrations from distinct agricultural and urban contamination sources in Eastern Canada, Cindy Lalancette, Mylène Généreux, Jacinthe Mailly, Pierre Servais, Caroline Côté, Aubert Michaud, George D. Di Giovanni and Michèle Prévost

2012 ◽  
Vol 10 (3) ◽  
pp. 497-497 ◽  
Keyword(s):  
Cryptosporidium Oocyst ◽  
Giardia Cyst ◽  
Eastern Canada ◽  
Contamination Sources

scholarly journals Total and infectious Cryptosporidium oocyst and total Giardia cyst concentrations from distinct agricultural and urban contamination sources in Eastern Canada

2011 ◽  
Vol 10 (1) ◽  
pp. 147-160 ◽  
Author(s):  
Cindy Lalancette ◽  
Mylène Généreux ◽  
Jacinthe Mailly ◽  
Pierre Servais ◽  
Caroline Côté ◽  
...  
Keyword(s):  
Wastewater Treatment Plants ◽  
Cryptosporidium Oocyst ◽  
Human Health Risk ◽  
Giardia Cyst ◽  
Quantitative Microbial Risk Assessment ◽  
Water Safety ◽  
Eastern Canada ◽  
Microbial Risk Assessment ◽  
Discharge Point ◽  
Drinking Water Safety

Cryptosporidium and Giardia (oo)cyst concentrations are frequently used for assessing drinking water safety. The widely used USEPA Method 1623 provides total counts of (oo)cysts, but may not be accurate for human health risk characterization, since it does not provide infectivity information. The total counts and infectious fraction of Cryptosporidium oocysts and the total counts of Giardia cysts were assessed in major fecal pollution sources. Fresh calf and cow feces, their manure, and the discharge point were sampled in a small rural sub-watershed (n = 20, 21, 10, 10). Median concentrations for total (oo)cysts were higher in calves (333 oocysts g−1; 111 cysts g−1) than in cows (52 oocysts g−1; 7 cysts g−1). Infectious oocysts were found in 17 (7%) of the samples and none were found in manure or at the discharge point. Urban sources were sampled in the influent and effluent (n = 19, 18) of two wastewater treatment plants. Peak concentrations were 533 oocysts L−1 and 9,010 cysts L−1 for influents and 89 oocysts L−1 and 472 cysts L−1 for effluents. Infectious oocyst fractions varied from below the detection limit to 7–22% in the effluent and influent respectively. These infectious fractions are significantly lower than those currently used for quantitative microbial risk assessment estimates.

Determination of the Recovery Efficiency of Cryptosporidium Oocysts and Giardia Cysts from Seeded Bivalve Mollusks

2013 ◽  
Vol 76 (1) ◽  
pp. 93-98 ◽  
Author(s):  
FRANCISKA M. SCHETS ◽  
HAROLD H. J. L. van den BERG ◽  
ANA MARIA de RODA HUSMAN
Keyword(s):  
Quantitative Assessment ◽  
Intestinal Parasites ◽  
Cryptosporidium Oocyst ◽  
Immunomagnetic Separation ◽  
Giardia Cyst ◽  
Bivalve Mollusks ◽  
Recovery Efficiency ◽  
Risk Of Infection ◽  
Cryptosporidium Oocysts

The intestinal parasites Cryptosporidium and Giardia are transmitted by water and food and cause human gastroenteritis. Filter-feeding bivalve mollusks, such as oysters and mussels, filter large volumes of water and thus concentrate such pathogens, which makes these bivalves potential vectors of disease. To assess the risk of infection from consumption of contaminated bivalves, parasite numbers and parasite recovery data are required. A modified immunomagnetic separation (IMS) procedure was used to determine Cryptosporidium oocyst and Giardia cyst numbers in individually homogenized oysters (Crassostrea gigas) and mussels (Mytilus edulis). About 12% of the commercial bivalves were positive, with low (oo)cyst numbers per specimen. The recovery efficiency of the IMS procedure was systematically evaluated. Experiments included seeding of homogenized bivalves and whole animals with 100 to 1,000 (oo)cysts. Both seeding procedures yielded highly variable recovery rates. Median Cryptosporidium recoveries were 7.9 to 21% in oysters and 62% in mussels. Median Giardia recoveries were 10 to 25% in oysters and 110% in mussels. Giardia recovery was significantly higher than Cryptosporidium recovery. (Oo)cysts were less efficiently recovered from seeded whole animals than from seeded homogenates, with median Cryptosporidium recoveries of 5.3% in oysters and 45% in mussels and median Giardia recoveries of 4.0% in oysters and 82% in mussels. Both bivalve homogenate seeding and whole animal seeding yielded higher (oo)cyst recovery in mussels than in oysters, likely because of the presence of less shellfish tissue in IMS when analyzing the smaller mussels compared with the larger oysters, resulting in more efficient (oo)cyst extraction. The data generated in this study may be used in the quantitative assessment of the risk of infection with Cryptosporidium or Giardia associated with the consumption of raw bivalve mollusks. This information may be used for making risk management decisions.

scholarly journals Risk of diarrhoea from shallow groundwater contaminated with enteropathogens in the Kathmandu Valley, Nepal

2014 ◽  
Vol 13 (1) ◽  
pp. 259-269 ◽  
Author(s):  
Sadhana Shrestha ◽  
Eiji Haramoto ◽  
Rabin Malla ◽  
Kei Nishida
Keyword(s):  
Water Treatment ◽  
Cryptosporidium Oocyst ◽  
Shallow Groundwater ◽  
Kathmandu Valley ◽  
Giardia Cyst ◽  
Quantitative Microbial Risk Assessment ◽  
Total Risk ◽  
E Coli ◽  
Tube Wells ◽  
Increased Risk

Shallow groundwater is the main water source among many alternatives in the Kathmandu Valley, Nepal, which has a rapidly growing population and intermittent piped water supply. Although human pathogens are detected in groundwater, its health effects are unclear. We estimated risk of diarrhoea from shallow groundwater use using quantitative microbial risk assessment. Escherichia coli, Giardia cyst and Cryptosporidium oocyst levels were analysed in dug and tube wells samples. E. coli concentrations were converted to those of enteropathogenic E. coli (EPEC). Risks from EPEC in dug wells and from Cryptosporidium and Giardia in both dug and tube wells were higher than the acceptable limit (<10−4 infections/person-year) for both drinking and bathing exposures. Risk from protozoan enteropathogens increased the total risk 10,000 times, indicating that ignoring protozoans could lead to serious risk underestimation. Bathing exposure considerably increased risk, indicating that it is an important pathway. Point-of-use (POU) water treatment decreased the risk six-fold and decreased risk overestimation. Because removal efficiency of POU water treatment has the largest impact on total risk, increasing the coverage and efficiency of POU water treatment could be a practical risk management strategy in the Kathmandu Valley and similar settings.

Source and occurrence of Giardia and Cryptosporidium in Paris rivers

2000 ◽  
Vol 41 (7) ◽  
pp. 79-86 ◽  
Author(s):  
V. Rouquet ◽  
F. Homer ◽  
J. M. Brignon ◽  
P. Bonne ◽  
J. Cavard
Keyword(s):  
Cryptosporidium Oocyst ◽  
Drinking Water Treatment ◽  
Quality Parameters ◽  
Point Sources ◽  
Risk Indicators ◽  
Giardia Cyst ◽  
Run Off ◽  
Rain Fall ◽  
High Concentrations ◽  
The Relationship

This paper presents an investigation of the variability of concentrations of Giardia cyst and Cryptosporidium oocyst in two main rivers of Ile-de-France: the Seine (upstream from Paris) and its largest tributary: the Marne. The first goal of this study was to examine risk of presence of Cryptosporidium and Giardia at the drinking water treatment plants' intakes at high concentrations. A second goal was to study the relationship between parasite concentrations and a variety of more easily measured water quality parameters (microbial or physicochemical) which could be used as risk indicators. Two aspects were particularly addressed: the influence of upstream waste water discharges, and the influence of rain fall and river floods on parasite concentrations. Preliminary results of an ongoing study are also presented: they show possible influence of non-point sources on parasite concentrations. Overall results show that parasite sedimentation in rivers is high, urban run-off and resuspension of particles could be at certain times the main factors responsible for peak pathogen levels in raw water.

scholarly journals Use of Artificial Neural Networks To Accurately Identify Cryptosporidium Oocyst and Giardia Cyst Images

2005 ◽  
Vol 71 (1) ◽  
pp. 80-84 ◽  
Author(s):  
Kenneth W. Widmer ◽  
Deepak Srikumar ◽  
Suresh D. Pillai
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Cryptosporidium Oocyst ◽  
Digital Camera ◽  
Gastrointestinal Diseases ◽  
Giardia Cyst ◽  
Human Errors ◽  
Negative Images ◽  
Total Magnification ◽  
Artificial Neural

ABSTRACT Cryptosporidium parvum and Giardia lamblia are protozoa capable of causing gastrointestinal diseases. Currently, these organisms are identified using immunofluorescent antibody (IFA)-based microscopy, and identification requires trained individuals for final confirmation. Since artificial neural networks (ANN) can provide an automated means of identification, thereby reducing human errors related to misidentification, ANN were developed to identify Cryptosporidium oocyst and Giardia cyst images. Digitized images of C. parvum oocysts and G. lamblia cysts stained with various commercial IFA reagents were used as positive controls. The images were captured using a color digital camera at 400� (total magnification), processed, and converted into a binary numerical array. A variety of “negative” images were also captured and processed. The ANN were developed using these images and a rigorous training and testing protocol. The Cryptosporidium oocyst ANN were trained with 1,586 images, while Giardia cyst ANN were trained with 2,431 images. After training, the best-performing ANN were selected based on an initial testing performance against 100 images (50 positive and 50 negative images). The networks were validated against previously “unseen” images of 500 Cryptosporidium oocysts (250 positive, 250 negative) and 282 Giardia cysts (232 positive, 50 negative). The selected ANNs correctly identified 91.8 and 99.6% of the Cryptosporidium oocyst and Giardia cyst images, respectively. These results indicate that ANN technology can be an alternate to having trained personnel for detecting these pathogens and can be a boon to underdeveloped regions of the world where there is a chronic shortage of adequately skilled individuals to detect these pathogens.

scholarly journals Removal of bacteria, protozoa and viruses through a multiple-barrier household water disinfection system

2013 ◽  
Vol 12 (1) ◽  
pp. 94-104 ◽  
Author(s):  
A. C. Espinosa-García ◽  
C. Díaz-Ávalos ◽  
R. Solano-Ortiz ◽  
M. A. Tapia-Palacios ◽  
N. Vázquez-Salvador ◽  
...  
Keyword(s):  
Mexico City ◽  
Cryptosporidium Oocyst ◽  
Water Disinfection ◽  
Giardia Cyst ◽  
E Coli ◽  
Water Characteristics ◽  
Removal Capacity ◽  
Household Water ◽  
Cryptosporidium Oocysts ◽  
Barrier Device

Municipal water disinfection systems in some areas are not always able to meet water consumer needs, such as ensuring distributed water quality, because household water management can be a contributing factor in water re-contamination. This fact is related to the storage options that are common in places where water is scarce or is distributed over limited time periods. The aim of this study is to assess the removal capacity of a multiple-barrier water disinfection device for protozoa, bacteria, and viruses. Water samples were taken from households in Mexico City and spiked with a known amount of protozoa (Giardia cyst, Cryptosporidium oocyst), bacteria (Escherichia coli), and viruses (rotavirus, adenovirus, F-specific ribonucleic acid (FRNA) coliphage). Each inoculated sample was processed through a multiple-barrier device. The efficiency of the multiple-barrier device to remove E. coli was close to 100%, and more than 87% of Cryptosporidium oocysts and more than 98% of Giardia cysts were removed. Close to 100% of coliphages were removed, 99.6% of the adenovirus was removed, and the rotavirus was almost totally removed. An effect of site by zone was detected; this observation is important because the water characteristics could indicate the efficiency of the multiple-barrier disinfection device.

Cryptosporidium spp. and Giardia spp. in surface water supply of Campinas, Southeast Brazil

2010 ◽  
Vol 62 (1) ◽  
pp. 217-222 ◽  
Author(s):  
Romeu Cantusio Neto ◽  
Luciana Urbano dos Santos ◽  
Maria Ines Zanoli Sato ◽  
Regina Maura Bueno Franco
Keyword(s):  
Surface Water ◽  
Membrane Filtration ◽  
Cryptosporidium Oocyst ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Immunomagnetic Separation ◽  
Immunofluorescence Assay ◽  
Giardia Cyst ◽  
Filtration Method ◽  
Cryptosporidium Spp

Surface water contaminated by domestic sewage discharges is a potential source of pathogens, including protozoa. During 2005–2006, the source water (Atibaia River) of the Surface Water Treatment Plant (WTP) of Campinas city, São Paulo, Brazil was sampled to obtain an assessment of Cryptosporidium oocyst and Giardia cyst concentrations. Calcium carbonate flocculation (CCF) and membrane filtration (MF) concentration techniques, with and without purification by immunomagnetic separation (IMS) were evaluated. The cysts and oocysts were detected by immunofluorescence assay (IFA) and confirmed by differential interference contrast (DIC). Membrane filtration method generally produced higher recovery efficiency. Giardia spp. was detected in 87.5% of the water samples analyzed with densities ranging from 2.5 to 120 cysts per L. Cryptosporidium spp were detected in 62.5% and the concentrations ranged from 15 to 60 oocysts per L. Cryptosporidium oocyst and Giardia cyst concentrations detected in this study were elevated and are associated with discharge of untreated sewage in Atibaia River. Measures should be taken to protect surface water from sources of contamination.

Giardia Cyst and Cryptosporidium Oocyst Survival in Water, Soil, and Cattle Feces

1999 ◽  
Vol 28 (6) ◽  
pp. 1991-1996 ◽  
Author(s):  
Merle E. Olson ◽  
Jeanette Goh ◽  
Michael Phillips ◽  
Nicole Guselle ◽  
Tim A. McAllister
Keyword(s):  
Cryptosporidium Oocyst ◽  
Giardia Cyst ◽  
Cattle Feces

scholarly journals Evaluation of Cryptosporidium oocyst and Giardia cyst removal efficiency from urban and slaughterhouse wastewater treatment plants and assessment of cyst viability in wastewater effluent samples from Tehran, Iran

2015 ◽  
Vol 5 (3) ◽  
pp. 372-390 ◽  
Author(s):  
Kareem Hatam-Nahavandi ◽  
Mehdi Mohebali ◽  
Amir-Hossein Mahvi ◽  
Hossein Keshavarz ◽  
Khadijeh Khanaliha ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Cryptosporidium Oocyst ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Wastewater Effluent ◽  
Giardia Cyst ◽  
Conventional Activated Sludge ◽  
The Difference

Five municipal and domestic wastewater treatment plants, most of which had secondary treatment systems formed by activated sludge, were studied during 2013–2014 in Tehran. The study was done in order to evaluate their efficiency in terms of removal of Cryptosporidium and Giardia by (oo)cyst recovery in effluent samples using immunofluorescence with monoclonal antibodies. Results showed that mean concentrations of cysts in the influent samples always outnumbered mean concentrations of oocysts (883.3 ± 4,16.7–3,191.7 ± 1,067.2 versus 4.8 ± 6.2–83.8 ± 77.3 (oo)cysts/L), and that lower concentrations of (oo)cysts were recorded in summer, and higher levels in autumn, and that the difference was statistically significant (t-test, P <0.05) only in wastewater from slaughterhouses. Results for removal percentages of all the plants ranged from 76.7 to 92.1% for cysts and from 48.9 to 90.8% for oocysts. There was more reduction of (oo)cysts at the urban treatment plant by activated sludge-A2O-sand filtration than at plants with conventional activated sludge and activated sludge-trickling filter, however, this difference was not statistically significant for cysts and oocysts (ANOVA, P > 0.05). Infections in mice inoculated with cysts obtained from urban wastewater effluent demonstrated presence of infectious Giardia cysts. Results demonstrate limited efficiency of conventional wastewater treatment processes at physico-chemical removal of (oo)cysts.

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