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Teel L, Pagilla K, Sundaram V, Li L, Guarin T, Haak L. Pathogen reduction by ozone-biological activated carbon-based advanced water reclamation for reuse. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2022; 94:e10726. [PMID: 35621226 DOI: 10.1002/wer.10726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 03/03/2022] [Accepted: 03/28/2022] [Indexed: 06/15/2023]
Abstract
Ozone-biological activated carbon (ozone-BAC)-based technologies are emerging as an appealing option for potable reuse systems; however, uncertainty remains regarding the reduction of waterborne pathogens. Common log reduction requirements have been modeled after California Department of Drinking Water's 12-10-10 log reduction value (LRV) for enteric virus, Cryptosporidium, and Giardia, respectively. The objective of this research was to investigate appropriate LRVs of pathogens that can be achieved in ozone-BAC-based treatment systems and to assess the applicability of employing drinking water pathogen guidelines for potable reuse applications. A pilot scale ozone-BAC-based treatment train was operated at two water reclamation facilities in Reno, Nevada, USA. Virus, Cryptosporidium, Giardia, and bacterial indicators were monitored across individual and combined treatment processes. Pathogen barriers investigated include conventional filtration, ozonation, and ultraviolet disinfection. Based on sampling and treatment validation strategies, the three pathogen barriers can provide minimum LRVs of 13-9-9.5 for virus, Giardia, and Cryptosporidium. Secondary biological treatment can provide additional pathogen LRVs with site-specific sampling. The present study addresses regulatory uncertainties associated with ozone-BAC pathogen reduction. PRACTITIONER POINTS: Ozone-biological activated carbon-based advanced treatment can meet pathogen LRV requirements with a minimum of three pathogen barriers. Successfully applied drinking water pathogen reduction guidelines for potable reuse applications verified by operational criteria. Low presence of pathogens requires surrogates and indicator analyses and variety of monitoring techniques to verify pathogen log reduction.
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Affiliation(s)
- Lydia Teel
- Department of Civil and Environmental, Engineering, University of Nevada, Reno, Reno, Nevada, USA
- Truckee Meadows Water Authority, Reno, Nevada, USA
| | - Krishna Pagilla
- Department of Civil and Environmental, Engineering, University of Nevada, Reno, Reno, Nevada, USA
| | | | - Lin Li
- Department of Civil and Environmental, Engineering, University of Nevada, Reno, Reno, Nevada, USA
| | - Tatiana Guarin
- Department of Civil and Environmental, Engineering, University of Nevada, Reno, Reno, Nevada, USA
| | - Laura Haak
- Department of Civil and Environmental, Engineering, University of Nevada, Reno, Reno, Nevada, USA
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Sojobi AO, Zayed T. Impact of sewer overflow on public health: A comprehensive scientometric analysis and systematic review. ENVIRONMENTAL RESEARCH 2022; 203:111609. [PMID: 34216613 DOI: 10.1016/j.envres.2021.111609] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 06/16/2021] [Accepted: 06/24/2021] [Indexed: 05/09/2023]
Abstract
Sewer overflow (SO), which has attracted global attention, poses serious threat to public health and ecosystem. SO impacts public health via consumption of contaminated drinking water, aerosolization of pathogens, food-chain transmission, and direct contact with fecally-polluted rivers and beach sediments during recreation. However, no study has attempted to map the linkage between SO and public health including Covid-19 using scientometric analysis and systematic review of literature. Results showed that only few countries were actively involved in SO research in relation to public health. Furthermore, there are renewed calls to scale up environmental surveillance to safeguard public health. To safeguard public health, it is important for public health authorities to optimize water and wastewater treatment plants and improve building ventilation and plumbing systems to minimize pathogen transmission within buildings and transportation systems. In addition, health authorities should formulate appropriate policies that can enhance environmental surveillance and facilitate real-time monitoring of sewer overflow. Increased public awareness on strict personal hygiene and point-of-use-water-treatment such as boiling drinking water will go a long way to safeguard public health. Ecotoxicological studies and health risk assessment of exposure to pathogens via different transmission routes is also required to appropriately inform the use of lockdowns, minimize their socio-economic impact and guide evidence-based welfare/social policy interventions. Soft infrastructures, optimized sewer maintenance and prescreening of sewer overflow are recommended to reduce stormwater burden on wastewater treatment plant, curtail pathogen transmission and marine plastic pollution. Comprehensive, integrated surveillance and global collaborative efforts are important to curtail on-going Covid-19 pandemic and improve resilience against future pandemics.
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Affiliation(s)
| | - Tarek Zayed
- Department of Building and Real Estate, The Hong Kong Polytechnic University, Hong Kong, China.
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Thompson KA, Dickenson ERV. Using machine learning classification to detect simulated increases of de facto reuse and urban stormwater surges in surface water. WATER RESEARCH 2021; 204:117556. [PMID: 34481284 DOI: 10.1016/j.watres.2021.117556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/28/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Water quality events such as increases in stormwater or wastewater effluent in drinking water sources pose hazards to drinking water consumers. Stormwater and wastewater effluent enter Lake Mead-an important drinking water source in the southwest USA-via the Las Vegas Wash. Previous studies have applied machine learning and online instruments to detect contamination in water distribution systems. However, alert systems at drinking water intakes would provide more time for corrective action. An array of online instruments measuring pH, conductivity, redox potential, turbidity, temperature, tryptophan-like fluorescence, UV absorbance (UVA254), TOC, and chlorophyll-a was fed raw water directly from Lake Mead. Wastewater effluent, dry weather Las Vegas Wash, and storm-impacted Las Vegas Wash samples were blended into the instrument inlets at known ratios to simulate three types of adverse water quality events. Data preprocessing was conducted to correct for diurnal patterns or instrument drift. Supervised machine learning was conducted using previously published models in R. Ninety-nine models were screened on the raw data. Eight high-performing models were evaluated in-depth and optimized. Weighted k-Nearest Neighbors, Single C5.0 Ruleset, Mixture Discriminant Analysis, and an ensemble of these three models had accuracy over 97% when assigning test set data among three classes (Normal, Event, or Maintenance). The ensemble detected all event types at the earliest timepoint and had one false positive that was not a lag error (i.e., consecutively following a true positive). Omitting Maintenance, the Adaboost model had over 99% test set accuracy and zero false positives that were not lag errors. Data preprocessing was beneficial, but the optimal methods were model-specific. All nine water quality variables were useful for most models, but UVA254 and turbidity were most important.
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Affiliation(s)
- Kyle A Thompson
- Water Quality Research and Development, Southern Nevada Water Authority, 1299 Burkholder Blvd., Henderson, United States; Carollo Engineers, Inc., 8911 N Capital of Texas Hwy, Austin, TX 78759, United States.
| | - Eric R V Dickenson
- Water Quality Research and Development, Southern Nevada Water Authority, 1299 Burkholder Blvd., Henderson, United States.
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Occurrence of Cryptosporidium Oocysts and Helminth Ova on Dried Crayfish (Procambarus clarkii) Sold in Kaduna State, Nigeria. FOLIA VETERINARIA 2021. [DOI: 10.2478/fv-2021-0004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Cryptosporidium spp. and helminths are responsible for diarrhoal illness in humans and many other animals. The transmission routes of these parasites suggest a risk for human infection through contaminated foods. In order to determine the occurrence of Cryptosporidium oocysts and helminth ova on dried crayfish (Procambarus clarkii) sold in Zaria and Kaduna Central market, Kaduna State, 100 crayfish samples were examined using the modified Ziehl-Neelsen staining technique for Cryptosporidium oocyst and the flotation technique for helminth ova. The measurements of the oocysts from the positive samples were estimated by using a calibrated microscope eyepiece. The prevalence of Cryptosporidium oocysts in dried crayfish was 20.0 % while the location-based prevalence was 43.3 %, 5.0 %, and 12.0 % for Sabo, Samaru and Kaduna central market, respectively. Micrometry revealed that the oocysts size ranged from 3.68 µm to 4.7 µm. Also, the prevalence of helminth ova in dried crayfish was 19 %, while the specific prevalence based on location showed a higher prevalence in Sabo (30.0 %) than in Kaduna central market (18.0 %) and Samaru (5.0 %). The helminth eggs recovered from this study included: Toxocara spp. (4.0 %), Ascaris spp. (7.0 %), Trichuris spp. (4.0 %), Schistosoma spp. (2.0 %), Ancylostoma spp. (1.0 %), and Capillaria spp. (1.0 %). The analysis of the questionnaires revealed that 71 (71.0 %) of the respondents ate uncooked cray-fish and 44.0 % used their bare hands to handle the cray-fish. There was no statistically significant association (P > 0.05) between the prevalence of Cryptosporidium oocysts or helminth ova and the locations sampled. This study has shown that dried crayfish obtained from markets within the study area were contaminated with parasite ova and oocysts, thus public enlightenment on the dangers of the consumption of raw or undercooked dried crayfish should be well publicized.
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Chelbi H, Essid R, Jelassi R, Bouzekri N, Zidi I, Ben Salah H, Mrad I, Ben Sghaier I, Abdelmalek R, Aissa S, Bouratbine A, Aoun K. High-resolution melting-curve (HRM) analysis for C. meleagridis identification in stool samples. Microb Pathog 2018; 115:332-337. [DOI: 10.1016/j.micpath.2017.12.070] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 12/22/2017] [Accepted: 12/28/2017] [Indexed: 10/18/2022]
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Bamaiyi PH, Redhuan NEM. Prevalence and risk factors for cryptosporidiosis: a global, emerging, neglected zoonosis. ASIAN BIOMED 2017. [DOI: 10.5372/1905-7415.1004.493] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Abstract
Background
Cryptosporidiosis is a zoonotic disease caused by the important parasitic diarrheal agent Cryptosporidium spp. Cryptosporidiosis occurs in all classes of animals and man with a rapidly expanding host range and increased importance since the occurrence of human immunodeficiency virus/acquired immunodeficiency syndrome in man.
Objectives
To review the global picture of cryptosporidiosis in man and animals with emphasis on prevalence and risk factors.
Methods
Current relevant literature on cryptosporidiosis was reviewed.
Results
Cryptosporidiosis is widely distributed and the risk factors vary from one region to another with hygiene and immune status as important risk factors.
Conclusions
Cryptosporidium spp. associated mortality has not only been reported in immune-compromised patients, but also in immune-competent patients. Yet in many countries not much attention is paid to the control and prevention of this infection in animals and man. The neglect of this disease despite the serious threat it poses to animals, their husbandry, and humans, has led the World Health Organization to list it among globally neglected diseases. To control and prevent this infection more effort needs to be directed at controlling the risk factors of the infection in man and animals.
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Affiliation(s)
- Pwaveno Huladeino Bamaiyi
- Faculty of Veterinary Medicine , Universiti Malaysia Kelantan , Kelantan 16100 , Malaysia
- Department of Public Health , School of Allied Health Sciences , Kampala International University , Kampala Uganda
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Abstract
Waterborne diseases are caused by a multitude of pathogens and associated with a significant burden in both developed and developing countries. While the assessment of the adverse impacts of climate change on human heath from infectious diseases has mainly focused on vector-borne diseases, waterborne diseases prevalence and transmission patterns are also likely to be impacted by environmental change. This chapter will outline relevant waterborne pathogens, summarise the impact of climate change on disease transmission and explore climate change adaptation options in order to reduce the increased burden of waterborne diseases.
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Van Rossum T, Peabody MA, Uyaguari-Diaz MI, Cronin KI, Chan M, Slobodan JR, Nesbitt MJ, Suttle CA, Hsiao WWL, Tang PKC, Prystajecky NA, Brinkman FSL. Year-Long Metagenomic Study of River Microbiomes Across Land Use and Water Quality. Front Microbiol 2015; 6:1405. [PMID: 26733955 PMCID: PMC4681185 DOI: 10.3389/fmicb.2015.01405] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/25/2015] [Indexed: 01/04/2023] Open
Abstract
Select bacteria, such as Escherichia coli or coliforms, have been widely used as sentinels of low water quality; however, there are concerns regarding their predictive accuracy for the protection of human and environmental health. To develop improved monitoring systems, a greater understanding of bacterial community structure, function, and variability across time is required in the context of different pollution types, such as agricultural and urban contamination. Here, we present a year-long survey of free-living bacterial DNA collected from seven sites along rivers in three watersheds with varying land use in Southwestern Canada. This is the first study to examine the bacterial metagenome in flowing freshwater (lotic) environments over such a time span, providing an opportunity to describe bacterial community variability as a function of land use and environmental conditions. Characteristics of the metagenomic data, such as sequence composition and average genome size (AGS), vary with sampling site, environmental conditions, and water chemistry. For example, AGS was correlated with hours of daylight in the agricultural watershed and, across the agriculturally and urban-affected sites, k-mer composition clustering corresponded to nutrient concentrations. In addition to indicating a community shift, this change in AGS has implications in terms of the normalization strategies required, and considerations surrounding such strategies in general are discussed. When comparing abundances of gene functional groups between high- and low-quality water samples collected from an agricultural area, the latter had a higher abundance of nutrient metabolism and bacteriophage groups, possibly reflecting an increase in agricultural runoff. This work presents a valuable dataset representing a year of monthly sampling across watersheds and an analysis targeted at establishing a foundational understanding of how bacterial lotic communities vary across time and land use. The results provide important context for future studies, including further analyses of watershed ecosystem health, and the identification and development of biomarkers for improved water quality monitoring systems.
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Affiliation(s)
- Thea Van Rossum
- Department of Molecular Biology and Biochemistry, Simon Fraser University Burnaby, BC, Canada
| | - Michael A Peabody
- Department of Molecular Biology and Biochemistry, Simon Fraser University Burnaby, BC, Canada
| | - Miguel I Uyaguari-Diaz
- Department of Pathology and Laboratory Medicine, University of British Columbia Vancouver, BC, Canada
| | - Kirby I Cronin
- Department of Pathology and Laboratory Medicine, University of British Columbia Vancouver, BC, Canada
| | - Michael Chan
- British Columbia Public Health Microbiology and Reference Laboratory, British Columbia Centre for Disease Control Vancouver, BC, Canada
| | | | | | - Curtis A Suttle
- Department of Microbiology and Immunology, University of British ColumbiaVancouver, BC, Canada; Department of Earth, Ocean and Atmospheric Sciences, University of British ColumbiaVancouver, BC, Canada; Department of Botany, University of British ColumbiaVancouver, BC, Canada; Canadian Institute for Advanced ResearchToronto, ON, Canada
| | - William W L Hsiao
- Department of Pathology and Laboratory Medicine, University of British ColumbiaVancouver, BC, Canada; British Columbia Public Health Microbiology and Reference Laboratory, British Columbia Centre for Disease ControlVancouver, BC, Canada
| | - Patrick K C Tang
- Department of Pathology and Laboratory Medicine, University of British ColumbiaVancouver, BC, Canada; British Columbia Public Health Microbiology and Reference Laboratory, British Columbia Centre for Disease ControlVancouver, BC, Canada
| | - Natalie A Prystajecky
- Department of Pathology and Laboratory Medicine, University of British ColumbiaVancouver, BC, Canada; British Columbia Public Health Microbiology and Reference Laboratory, British Columbia Centre for Disease ControlVancouver, BC, Canada
| | - Fiona S L Brinkman
- Department of Molecular Biology and Biochemistry, Simon Fraser University Burnaby, BC, Canada
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Rochelle PA, Klonicki PT, Di Giovanni GD, Hill VR, Akagi Y, Villegas EN. Conference Report: The 6th International Symposium on Waterborne Pathogens. ACTA ACUST UNITED AC 2015; 107:24-32. [PMID: 26566291 DOI: 10.5942/jawwa.2015.107.0156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Paul A Rochelle
- Source water microbiology team manager at the Metropolitan Water District of Southern California (MWDSC), La Verne
| | | | - George D Di Giovanni
- Professor at the University of Texas-Houston School of Public Health, El Paso, Tex
| | - Vincent R Hill
- Environmental engineer at the Centers for Disease Control and Prevention, Atlanta, Ga
| | - Yone Akagi
- Water quality compliance manager for the City of Portland Water Bureau, Portland, Ore
| | - Eric N Villegas
- Research microbiologist at the US Environmental Protection Agency, Cincinnati, Ohio
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Communitywide cryptosporidiosis outbreak associated with a surface water-supplied municipal water system--Baker City, Oregon, 2013. Epidemiol Infect 2015; 144:274-84. [PMID: 26264893 DOI: 10.1017/s0950268815001831] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Cryptosporidium, a parasite known to cause large drinking and recreational water outbreaks, is tolerant of chlorine concentrations used for drinking water treatment. Human laboratory-based surveillance for enteric pathogens detected a cryptosporidiosis outbreak in Baker City, Oregon during July 2013 associated with municipal drinking water. Objectives of the investigation were to confirm the outbreak source and assess outbreak extent. The watershed was inspected and city water was tested for contamination. To determine the community attack rate, a standardized questionnaire was administered to randomly sampled households. Weighted attack rates and confidence intervals (CIs) were calculated. Water samples tested positive for Cryptosporidium species; a Cryptosporidium parvum subtype common in cattle was detected in human stool specimens. Cattle were observed grazing along watershed borders; cattle faeces were observed within watershed barriers. The city water treatment facility chlorinated, but did not filter, water. The community attack rate was 28·3% (95% CI 22·1-33·6), sickening an estimated 2780 persons. Watershed contamination by cattle probably caused this outbreak; water treatments effective against Cryptosporidium were not in place. This outbreak highlights vulnerability of drinking water systems to pathogen contamination and underscores the need for communities to invest in system improvements to maintain multiple barriers to drinking water contamination.
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A Delphi Technology Foresight Study: Mapping Social Construction of Scientific Evidence on Metagenomics Tests for Water Safety. PLoS One 2015; 10:e0129706. [PMID: 26066837 PMCID: PMC4465892 DOI: 10.1371/journal.pone.0129706] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 05/12/2015] [Indexed: 11/19/2022] Open
Abstract
Access to clean water is a grand challenge in the 21st century. Water safety testing for pathogens currently depends on surrogate measures such as fecal indicator bacteria (e.g., E. coli). Metagenomics concerns high-throughput, culture-independent, unbiased shotgun sequencing of DNA from environmental samples that might transform water safety by detecting waterborne pathogens directly instead of their surrogates. Yet emerging innovations such as metagenomics are often fiercely contested. Innovations are subject to shaping/construction not only by technology but also social systems/values in which they are embedded, such as experts’ attitudes towards new scientific evidence. We conducted a classic three-round Delphi survey, comprised of 107 questions. A multidisciplinary expert panel (n = 24) representing the continuum of discovery scientists and policymakers evaluated the emergence of metagenomics tests. To the best of our knowledge, we report here the first Delphi foresight study of experts’ attitudes on (1) the top 10 priority evidentiary criteria for adoption of metagenomics tests for water safety, (2) the specific issues critical to governance of metagenomics innovation trajectory where there is consensus or dissensus among experts, (3) the anticipated time lapse from discovery to practice of metagenomics tests, and (4) the role and timing of public engagement in development of metagenomics tests. The ability of a test to distinguish between harmful and benign waterborne organisms, analytical/clinical sensitivity, and reproducibility were the top three evidentiary criteria for adoption of metagenomics. Experts agree that metagenomic testing will provide novel information but there is dissensus on whether metagenomics will replace the current water safety testing methods or impact the public health end points (e.g., reduction in boil water advisories). Interestingly, experts view the publics relevant in a “downstream capacity” for adoption of metagenomics rather than a co-productionist role at the “upstream” scientific design stage of metagenomics tests. In summary, these findings offer strategic foresight to govern metagenomics innovations symmetrically: by identifying areas where acceleration (e.g., consensus areas) and deceleration/reconsideration (e.g., dissensus areas) of the innovation trajectory might be warranted. Additionally, we show how scientific evidence is subject to potential social construction by experts’ value systems and the need for greater upstream public engagement on metagenomics innovations.
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Zhao W, Wang R, Zhang W, Liu A, Cao J, Shen Y, Yang F, Zhang L. MLST subtypes and population genetic structure of Cryptosporidium andersoni from dairy cattle and beef cattle in northeastern China's Heilongjiang Province. PLoS One 2014; 9:e102006. [PMID: 24999982 PMCID: PMC4084942 DOI: 10.1371/journal.pone.0102006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 06/13/2014] [Indexed: 11/19/2022] Open
Abstract
Cattle are the main reservoir host of C. andersoni, which shows a predominance in yearlings and adults of cattle. To understand the subtypes of C. andersoni and the population genetic structure in Heilongjiang Province, fecal specimens were collected from 420 dairy cattle and 405 beef cattle at the age of 12-14 months in eight cattle farms in five areas within this province and were screened for the presence of Cryptosporidium oocysts by microscopy after Sheather's sugar flotation technique. The average prevalence of Cryptosporidium spp. was 19.15% (158/825) and all the Cryptosporidium isolates were identified as C. andersoni by the SSU rRNA gene nested PCR-RFLP using SspI, VspI and MboII restriction enzymes. A total of 50 C. andersoni isolates were randomly selected and sequenced to confirm the RFLP results before they were subtyped by multilocus sequence typing (MLST) at the four microsatellite/minisatellite loci (MS1, MS2, MS3 and MS16). Four, one, two and one haplotypes were obtained at the four loci, respectively. The MLST subtype A4,A4,A4,A1 showed an absolute predominance and a wide distribution among the six MLST subtypes obtained in the investigated areas. Linkage disequilibrium analysis showed the presence of a clonal population genetic structure of C. andersoni in cattle, suggesting the absence of recombination among lineages. The finding of a clonal population genetic structure indicated that the prevalence of C. andersoni in cattle in Heilongjiang Province is not attributed to the introduction of cattle. Thus, prevention and control strategies should be focused on making stricter measures to avoid the occurrence of cross-transmission and re-infection between cattle individuals. These molecular data will also be helpful to explore the source attribution of infection/contamination of C. andersoni and to elucidate its transmission dynamics in Heilongjiang Province, even in China.
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Affiliation(s)
- Wei Zhao
- Department of Parasitology, Harbin Medical University, Harbin, Heilongjiang, China
| | - Rongjun Wang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University Zhengzhou, Henan, China
| | - Weizhe Zhang
- Department of Parasitology, Harbin Medical University, Harbin, Heilongjiang, China
| | - Aiqin Liu
- Department of Parasitology, Harbin Medical University, Harbin, Heilongjiang, China
- * E-mail: (AL); (LZ)
| | - Jianping Cao
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, Ministry of Health, WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, China
| | - Yujuan Shen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, Ministry of Health, WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, Shanghai, China
| | - Fengkun Yang
- Department of Parasitology, Harbin Medical University, Harbin, Heilongjiang, China
| | - Longxian Zhang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University Zhengzhou, Henan, China
- * E-mail: (AL); (LZ)
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Zhao Z, Dong H, Wang R, Zhao W, Chen G, Li S, Qi M, Zhang S, Jian F, Zhao J, Zhang L, Wang H, Liu A. Genotyping and subtyping Cryptosporidium parvum and Giardia duodenalis carried by flies on dairy farms in Henan, China. Parasit Vectors 2014; 7:190. [PMID: 24742088 PMCID: PMC4005625 DOI: 10.1186/1756-3305-7-190] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 04/06/2014] [Indexed: 11/24/2022] Open
Abstract
Background Cryptosporidium and Giardia are important causes of diarrhea diseases in humans and animals worldwide, and both of them are transmitted by the fecal–oral route, either by direct contact or by the ingestion of contaminated food or water. The role of flies in the mechanical transmission of Cryptosporidium and Giardia has been receiving increasing attention. To date, no information is available in China about the occurrence of Cryptosporidium and Giardia in flies. We here investigated Cryptosporidium and Giardia in flies on dairy farms in Henan Province, China, at the genotype and subtype levels. Methods Eight hundred flies were randomly collected from two dairy farms from July 2010 to September 2010 and were divided evenly into 40 batches. The fly samples were screened for the presence of Cryptosporidium and Giardia with nested PCR. Cryptosporidium was genotyped and subtyped by analyzing the DNA sequences of small subunit rRNA (SSU rRNA) and 60-kDa glycoprotein (gp60) genes, respectively. The identity of Giardia was determined by sequence analyzing of the triosephosphate isomerase (tpi), glutamate dehydrogenase (gdh), and β-giardin (bg) genes. Results Forty batches of flies had 10% of contamination with Cryptosporidium or Giardia, with a mixed infection of the two parasites in one batch of flies. The Cryptosporidium isolates were identified as C. parvum at the SSU rRNA locus, and all belonged to subtype IIdA19G1 at the gp60 locus. The Giardia isolates were all identified as assemblage E of G. duodenalis at the tpi, gdh, and bg loci. One novel subtype of assemblage E was identified based on the gdh and bg loci. Conclusions This is the first molecular study of Cryptosporidium and Giardia in flies identified at both genotype and subtype levels. SSU rRNA and gp60 sequences of C. parvum in flies was 100% homologous with those derived from humans, suggesting flies act as an epidemiological vector of zoonotic cryptosporidiosis. The variable PCR efficiencies observed in the analysis of Giardia at different loci suggest that we should use the multilocus genotyping tool in future studies to increase the detection rate, and importantly, to obtain more complete genetic information on Giardia isolates.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Longxian Zhang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, PR China.
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Assessment of Giardia and Cryptosporidium spp. as a microbial source tracking tool for surface water: application in a mixed-use watershed. Appl Environ Microbiol 2014; 80:2328-36. [PMID: 24463970 DOI: 10.1128/aem.02037-13] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Knowledge of host specificity, combined with genomic sequencing of Giardia and Cryptosporidium spp., has demonstrated a microbial source tracking (MST) utility for these common waterborne microbes. To explore the source attribution potential of these pathogens, water samples were collected in a mixed rural-urban watershed in the Township of Langley, in southwestern British Columbia (BC), Canada, over a 2-year period. Cryptosporidium was detected in 63% of surface water samples at concentrations ranging from no positive detection (NPD) to 20,600 oocysts per 100 liters. Giardia was detected in 86% of surface water samples at concentrations ranging from NPD to 3,800 cysts per 100 liters of water. Sequencing at the 18S rRNA locus revealed that 50% of Cryptosporidium samples and 98% of Giardia samples contained species/genotypes (Cryptosporidium) or assemblages (Giardia) that are capable of infecting humans, based on current knowledge of host specificity and taxonomy. Cryptosporidium genotyping data were more promising for source tracking potential, due to the greater number of host-adapted (i.e., narrow-host-range) species/genotypes compared to Giardia, since 98% of Giardia isolates were zoonotic and the potential host could not be predicted. This report highlights the benefits of parasite genomic sequencing to complement Method 1623 (U.S. Environmental Protection Agency) and shows that Cryptosporidium subtyping for MST purposes is superior to the use of Giardia subtyping, based on better detection limits for Cryptosporidium-positive samples than for Giardia-positive samples and on greater host specificity among Cryptosporidium species. These additional tools could be used for risk assessment in public health and watershed management decisions.
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Aniesona AT, Bamaiyi PH. Retrospective study of cryptosporidiosis among diarrhoeic children in the arid region of north-eastern Nigeria. Zoonoses Public Health 2013; 61:420-6. [PMID: 24245998 DOI: 10.1111/zph.12088] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Indexed: 11/30/2022]
Abstract
A retrospective study was carried out to investigate the prevalence of Cryptosporidium oocysts among diarrhoeic children (n = 650), aged between 0 and 15 years, living in Maiduguri metropolis (n = 220), Bama local government area (n = 278) and Gwoza local government area (n = 152). Stool samples were concentrated using the ethyl acetate sedimentation method. Data of stool samples with Cryptosporidium oocysts from patients within the specified age groups were collected and analysed. The overall prevalence was 42.9%. The prevalence was higher in Maiduguri metropolis 45.0%, which is an urban area as compared to Gwoza and Bama combined together 41.8% which are rural areas but not statistically significant at 95% confidence level (P > 0.05; OR = 1.14; CI = 0.82, 1.58). According to age, the prevalence in age group A (0-10 years) was higher (46.8%) as compared to age group B (11 < 15 years), which was 20.8%, and this was statistically significant at 95% confidence level (P < 0.05; OR = 3.34; CI = 1.98, 5.61). According to gender, males showed a higher prevalence (52.5%) compared with females (47.5%), but this was not statistically significant at 95% confidence level (P > 0.05; OR = 1.13; CI = 0.82, 1.53). Seasonal prevalence showed that hot dry months of March and April were higher compared with other months. Our findings indicate the presence of the pathogen in children in Borno State, Nigeria, with higher odds of the infection in younger children, and dry months may be more associated with the infection. Control and preventive measures should be taken to protect younger children from the infection.
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Affiliation(s)
- A T Aniesona
- Department of Veterinary Microbiology and Parasitology, University of Maiduguri, Maiduguri, Nigeria; Department of Microbiology, Faculty of Science, University of Maiduguri, Maiduguri, Nigeria
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Abstract
Cryptosporidium is a protozoan parasite of medical and veterinary importance that causes gastroenteritis in a variety of vertebrate hosts. Several studies have reported different degrees of pathogenicity and virulence among Cryptosporidium species and isolates of the same species as well as evidence of variation in host susceptibility to infection. The identification and validation of Cryptosporidium virulence factors have been hindered by the renowned difficulties pertaining to the in vitro culture and genetic manipulation of this parasite. Nevertheless, substantial progress has been made in identifying putative virulence factors for Cryptosporidium. This progress has been accelerated since the publication of the Cryptosporidium parvum and C. hominis genomes, with the characterization of over 25 putative virulence factors identified by using a variety of immunological and molecular techniques and which are proposed to be involved in aspects of host-pathogen interactions from adhesion and locomotion to invasion and proliferation. Progress has also been made in the contribution of host factors that are associated with variations in both the severity and risk of infection. Here we provide a review comprised of the current state of knowledge on Cryptosporidium infectivity, pathogenesis, and transmissibility in light of our contemporary understanding of microbial virulence.
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Sarkar R, Ajjampur SSR, Prabakaran AD, Geetha JC, Sowmyanarayanan TV, Kane A, Duara J, Muliyil J, Balraj V, Naumova EN, Ward H, Kang G. Cryptosporidiosis among children in an endemic semiurban community in southern India: does a protected drinking water source decrease infection? Clin Infect Dis 2013; 57:398-406. [PMID: 23709650 DOI: 10.1093/cid/cit288] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND A quasi-experimental study was conducted to determine whether or not a protected water supply (bottled drinking water) could prevent or delay cryptosporidial infections among children residing in an endemic community. METHODS A total of 176 children residing in a semiurban slum area in southern India were enrolled preweaning and received either bottled (n = 90) or municipal (n = 86) drinking water based on residence in specific streets. Weekly surveillance visits were conducted until children reached their second birthday. Stool samples were collected every month and during diarrheal episodes, and were tested for the presence of Cryptosporidium species by polymerase chain reaction. Differences in the incidence of cryptosporidiosis between bottled and municipal water groups were compared using Poisson survival models, and a propensity score model was developed to adjust for the effect of potential confounders. RESULTS A total of 186 episodes of cryptosporidiosis, mostly asymptomatic, were observed in 118 (67%) children during the follow-up period at a rate of 0.59 episodes per child-year. Diarrhea associated with Cryptosporidium species tended to be longer in duration and more severe. Stunting at 6 months was associated with a higher risk of cryptosporidiosis (rate ratio [RR] = 1.40; 95% confidence interval [CI], 1.03-1.91). A higher gastrointestinal disease burden was also seen in children with cryptosporidiosis. Drinking bottled water was not associated with a reduced risk of cryptosporidiosis (adjusted RR = 0.86; 95% CI, .60-1.23). CONCLUSIONS This study documented a high burden of cryptosporidiosis among children in an endemic Indian slum community. The lack of association between drinking bottled water and cryptosporidiosis suggests possible spread from asymptomatically infected individuals involving multiple transmission pathways.
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Affiliation(s)
- Rajiv Sarkar
- Department of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
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Keserue HA, Füchslin HP, Wittwer M, Nguyen-Viet H, Nguyen TT, Surinkul N, Koottatep T, Schürch N, Egli T. Comparison of rapid methods for detection of Giardia spp. and Cryptosporidium spp. (oo)cysts using transportable instrumentation in a field deployment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:8952-8959. [PMID: 22816735 DOI: 10.1021/es301974m] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Reliable, sensitive, quantitative, and mobile rapid screening methods for pathogenic organisms are not yet readily available, but would provide a great benefit to humanitarian intervention units in disaster situations. We compared three different methods (immunofluorescent microscopy, IFM; flow cytometry, FCM; polymerase chain reaction, PCR) for the rapid and quantitative detection of Giardia lamblia and Cryptosporidium parvum (oo)cysts in a field campaign. For this we deployed our mobile instrumentation and sampled canal water and vegetables during a 2 week field study in Thailand. For purification and concentrations of (oo)cysts, we used filtration and immunomagnetic separation. We were able to detect considerably high oo(cysts) concentrations (ranges: 15-855 and 0-240 oo(cysts)/liter for Giardia and Cryptosporidium, respectively) in 85 to 300 min, with FCM being fastest, followed by PCR, and IFM being slowest due to the long analysis time per sample. FCM and IFM performed consistently well, whereas PCR reactions often failed. The recovery, established by FCM, was around 30% for Giardia and 13% for Cryptosporidium (oo)cysts. It was possible to track (oo)cysts from the wastewater further downstream to irrigation waters and confirm contamination of salads and water vegetables. We believe that rapid detection, in particular FCM-based methods, can substantially help in disaster management and outbreak prevention.
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Affiliation(s)
- Hans-Anton Keserue
- Swiss Federal Institute for Aquatic Science and Technology (Eawag), Überlandstrasse 133, P.O. Box 611, CH-8600, Dübendorf, Switzerland
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Bonatti H, Barroso LF, Sawyer RG, Kotton CN, Sifri CD. Cryptosporidium enteritis in solid organ transplant recipients: multicenter retrospective evaluation of 10 cases reveals an association with elevated tacrolimus concentrations. Transpl Infect Dis 2012; 14:635-48. [PMID: 22340660 DOI: 10.1111/j.1399-3062.2012.00719.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 11/04/2011] [Accepted: 01/09/2012] [Indexed: 02/06/2023]
Abstract
BACKGROUND Cryptosporidial enteritis, a diarrheal infection of the small intestine caused by the apicomplexan protozoa Cryptosporidium, is infrequently recognized in transplant recipients from developed countries. METHODS A retrospective review of all cases of cryptosporidiosis in solid organ transplant (SOT) recipients at 2 centers from January 2001 to October 2010 was performed and compared with transplant recipients with community-onset Clostridium difficile infection (CDI). A literature search was performed with regard to reported cases of cryptosporidiosis in SOT recipients. RESULTS Eight renal, 1 liver, and 1 lung transplant recipient were diagnosed with cryptosporidiosis at median 46.0 months (interquartile range [IQR] 25.2-62.8) following SOT. Symptoms existed for a median 14 days (IQR 10.5-14.8) before diagnosis. For the 9 patients receiving tacrolimus (TAC), mean TAC levels increased from 6.3 ± 1.1 to 21.3 ± 9.2 ng/mL (P = 0.0007) and median serum creatinine increased temporarily from 1.3 (IQR 1.1-1.7) to 2.4 (IQR 2.0-4.6) mg/dL (P = 0.008). By comparison, 8 SOT recipients (6 kidney, 2 liver) hospitalized with community-onset CDI had a mean TAC level of 10.8 ± 2.8 ng/dL during disease compared with 9.2 ± 2.3 ng/mL at baseline (P = 0.07) and had no change in median creatinine. All patients recovered from Cryptosporidium enteritis after receiving various chemotherapeutic regimens. CONCLUSIONS Cryptosporidiosis should be recognized as an important cause of diarrhea after SOT and is associated with elevated TAC levels and acute kidney injury. Increased TAC levels may reflect altered drug metabolism in the small intestine.
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Affiliation(s)
- H Bonatti
- Department of Surgery, University of Virginia Health System, Charlottesville, Virginia, USA
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20
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Jex AR, Gasser RB. Genetic richness and diversity in Cryptosporidium hominis and C. parvum reveals major knowledge gaps and a need for the application of "next generation" technologies--research review. Biotechnol Adv 2010; 28:17-26. [PMID: 19699288 DOI: 10.1016/j.biotechadv.2009.08.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 08/07/2009] [Accepted: 08/08/2009] [Indexed: 11/26/2022]
Abstract
Cryptosporidium species (apicomplexan protists) are a major cause of diarrhoeal disease (= cryptosporidiosis) in humans worldwide. The impact of cryptosporidiosis is also compounded by the spread of HIV/AIDS and a lack of cost-effective anti-cryptosporidial chemotherapeutics or vaccines. Mitigation of the impact of cryptosporidiosis in humans needs to focus on prevention and control strategies, built on a sound understanding of the epidemiology of Cryptosporidium species. Refined epidemiological studies rely on the use of molecular tools employing informative genetic markers. Currently, the 60-kDa glycoprotein gene (gp60) is the most suitable and widely used genetic marker for Cryptosporidium species infecting humans. Here, we undertake an analysis of all publicly-available gp60 sequence data and associated literature for C. hominis and C. parvum, and yield useful insights into the richness, diversity and distribution of genetic variants, and link these variants to human cryptosporidiosis. This global analysis reveals that, despite high genetic richness in Cryptosporidium isolates from humans, there is a surprisingly low diversity. It also highlights limited knowledge about the genetics of cryptosporidiosis in developing nations and in many animals that might act as infection sources. Clearly, there is a major need for more comprehensive studies of Cryptosporidium infecting humans and other animals in Africa and Asia. As molecular technologies improve and become affordable, future studies should utilize "next generation" sequencing and bioinformatic platforms to conduct comparative 'genome sequence surveys' to test the validity of current genetic classifications based on gp60 data. Complemented by in vitro and in vivo investigations, these biotechnological advances will also assist significantly in the search for new intervention strategies against human cryptosporidiosis.
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Affiliation(s)
- Aaron R Jex
- Department of Veterinary Science, The University of Melbourne, Werribee, Victoria 3030, Australia.
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Colford JM, Hilton JF, Wright CC, Arnold BF, Saha S, Wade TJ, Scott J, Eisenberg JNS. The Sonoma water evaluation trial: a randomized drinking water intervention trial to reduce gastrointestinal illness in older adults. Am J Public Health 2009; 99:1988-95. [PMID: 19762663 PMCID: PMC2759780 DOI: 10.2105/ajph.2008.153619] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2009] [Indexed: 11/04/2022]
Abstract
OBJECTIVES We estimated the relative rate of highly credible gastrointestinal illness (HCGI) per year associated with active versus sham household water filtration devices among older adults in a community receiving tap water meeting current US standards. METHODS We conducted a randomized, triple-blinded, crossover trial in 714 households (988 individuals), which used active and sham water filtration devices for 6 months each. We estimated the annual incidence rate ratio of HCGI episodes and the longitudinal prevalence ratio of HCGI days at population and individual levels with a generalized estimating equation (GEE) and generalized linear mixed models (GLMMs), respectively, adjusted for covariates associated with outcome. RESULTS The incidence rate ratios (active versus sham) were 0.88 (95% confidence interval [CI] = 0.77, 1.00) and 0.85 (95% CI = 0.76, 0.94) HCGI episodes per year estimated by GEE and GLMM models, respectively. The corresponding longitudinal prevalence ratios were 0.88 (95% CI = 0.74, 1.05) and 0.84 (95% CI = 0.78, 0.90) HCGI days per person per year. CONCLUSIONS We observed reductions in population- and individual-level measures of HCGI associated with use of the active filtration device. These findings suggest the need for further research on the impact of drinking water on the health of sensitive subpopulations.
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Affiliation(s)
- John M Colford
- School of Public Health, University of California, 50 University Hall, MC 7360, Berkeley, CA 94720-7360, USA.
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22
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Massive outbreak of viral gastroenteritis associated with consumption of municipal drinking water in a European capital city. Epidemiol Infect 2009; 137:1713-20. [PMID: 19534843 DOI: 10.1017/s095026880999015x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
On 24 August 2008, an outbreak alert regarding cases of acute gastroenteritis in Podgorica triggered investigations to guide control measures. From 23 August to 7 September, 1699 cases were reported in Podgorica (population 136 000) and we estimated the total size of the outbreak to be 10 000-15 000 corresponding to an attack rate of approximately 10%. We conducted an age- and neighbourhood-matched case-control study, microbiologically analysed faecal and municipal water samples and assessed the water distribution system. All cases (83/83) and 90% (80/90) [corrected] of controls drank unboiled chlorinated municipal water [matched odds ratio (mOR) 11.2, 95% confidence interval (CI), 1.6-infinity]. Consumption of bottled water was inversely associated with illness (mOR 0.3, 95% CI 0.1-0.8). Analyses of faecal samples identified six norovirus genotypes (21/38 samples) and occasionally other viruses. Multiple defects in the water distribution system were noted. These results suggest that the outbreak was caused by faecally contaminated municipal water. It is unusual to have such a large outbreak in a European city especially when the municipal water supply is chlorinated. Therefore, it is important to establish effective multiple-barrier water-treatment systems whenever possible, but even with an established chlorinated supply, sustained vigilance is central to public health.
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von Oettingen J, Nath-Chowdhury M, Ward BJ, Rodloff AC, Arrowood MJ, Ndao M. High-yield amplification of Cryptosporidium parvum in interferon gamma receptor knockout mice. Parasitology 2008; 135:1151-6. [PMID: 18667105 DOI: 10.1017/s0031182008004757] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
To date, large-scale production of Cryptosporidium parvum oocysts has only been achieved by amplification in neonatal calves and sheep. Many laboratories currently depend on supplies from external sources and store oocysts for prolonged periods which results in progressive loss of viability. Six to 8-week-old interferon gamma receptor knockout (IFN gamma R-KO) mice on a C57BL/6 background were inoculated by gavage (2000 oocysts/animal). Fecal pellets were collected daily from 7 days post-infection (p.i.) up to 2 weeks p.i. Intestinal oocyst yield was assessed at days 11, 12 and 14 p.i. by homogenization of intestinal tissues. Ether extraction and one or more NaCl flotations were used to purify oocysts. Total recoveries averaged 2.6 x 10(6) oocysts/mouse from fecal material and 3.8 x 10(7) oocysts/mouse from intestinal tissues. Overall, 2.3 x 10(9) purified oocysts were obtained from 60 mice. Recovered oocysts were capable of sporulation and were shown to be infectious both in vitro and in vivo. Oocyst amplification was achieved in only 11-14 days with minimal expense. The simplicity of this method presents a practical alternative for the routine passage, maintenance and storage of C. parvum in biomedical laboratories.
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Affiliation(s)
- J von Oettingen
- National Reference Centre for Parasitology, Research Institute of the McGill University Heath Centre, Montreal General Hospital Research Institute, Montreal, Canada
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Redman RL, Nenn CA, Eastwood D, Gorelick MH. Pediatric emergency department visits for diarrheal illness increased after release of undertreated sewage. Pediatrics 2007; 120:e1472-5. [PMID: 18055664 DOI: 10.1542/peds.2007-0283] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
CONTEXT Contamination of local waterways may occur through release of partially treated sewage. The Environmental Protection Agency has recently reviewed regulatory standards for this practice. However, the health effects of these events have not been well studied. OBJECTIVE Our goal was to identify any increase in visits to a pediatric emergency department for diarrheal illness after sewage bypass into Lake Michigan. METHODS The study was conducted as a retrospective, observational time-series analysis in a tertiary care children's hospital emergency department with an annual volume of approximately 45,000 visits. We collected data for 2002-2004 pertaining to the daily number of emergency department visits for children (aged <19 years) for diarrheal illness (using specified International Classification of Diseases, Ninth Edition codes as a reference). Daily diarrheal illness visits were the dependent variable in a time-series model. The primary independent variable was the occurrence of a sewage-bypass event in the 3 to 7 preceding days. Potential confounders included the season and daily rainfall. Separate models were created for visits from people living in zip codes that used Lake Michigan drinking water and those who used other water sources. RESULTS Over the 3-year study period, there was a mean of 5.0 +/- 3.8 (SD) daily visits for diarrheal illness from people who lived in zip codes that used Lake Michigan drinking water and 1.2 +/- 1.4 (SD) from outside that area. There were 6 sewage-bypass events identified. After adjusting for the season and rainfall, there was a significant increase of 2.5 to 2.7 visits only from people who lived in zip codes that used Lake Michigan drinking water after the 2 largest of the 6 bypass events. CONCLUSIONS Emergency department visits for diarrheal illness increased significantly after 2 events of release of partially treated sewage into area waterways. These data suggest a potentially harmful effect of such practices.
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Affiliation(s)
- Ryan L Redman
- Emergency Department, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
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Srisuphanunt M, Suvedyathavorn V, Suputtamongkol Y, Arnantapunpong S, Wiwanitkit V, Satitvipawee P, Tansupasawadikul S. Potential risk factors for Cryptosporidium infection among HIV/AIDS patients in central areas of Thailand. J Public Health (Oxf) 2007. [DOI: 10.1007/s10389-007-0158-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Adesiji YO, Lawal RO, Taiwo SS, Fayemiwo SA, Adeyeba OA. CRYPTOSPORIDIOSIS IN HIV INFECTED PATIENTS WITH DIARRHOEA IN OSUN STATE SOUTHWESTERN NIGERIA. ELECTRONIC JOURNAL OF GENERAL MEDICINE 2007. [DOI: 10.29333/ejgm/82505] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zmirou-Navier D, Gofti-Laroche L, Hartemann P. Waterborne microbial risk assessment: a population-based dose-response function for Giardia spp. (E.MI.R.A study). BMC Public Health 2006; 6:122. [PMID: 16672062 PMCID: PMC1468406 DOI: 10.1186/1471-2458-6-122] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Accepted: 05/03/2006] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Dose-response parameters based on clinical challenges are frequently used to assess the health impact of protozoa in drinking water. We compare the risk estimates associated with Giardia in drinking water derived from the dose-response parameter published in the literature and the incidence of acute digestive conditions (ADC) measured in the framework of an epidemiological study in a general population. METHODS The study combined a daily follow-up of digestive morbidity among a panel of 544 volunteers and a microbiological surveillance of tap water. The relationship between incidence of ADC and concentrations of Giardia cysts was modeled with Generalized Estimating Equations, adjusting on community, age, tap water intake, presence of bacterial indicators, and genetic markers of viruses. The quantitative estimate of Giardia dose was the product of the declared amount of drinking water intake (in L) by the logarithm of cysts concentrations. RESULTS The Odds Ratio for one unit of dose [OR = 1.76 (95% CI: 1.21, 2.55)] showed a very good consistency with the risk assessment estimate computed after the literature dose-response, provided application of a 20 % abatement factor to the cysts counts that were measured in the epidemiological study. Doing so, a daily water intake of 2 L and a Giardia concentration of 10 cysts/100 L, would yield an estimated relative excess risk of 12 % according to the Rendtorff model, against 11 % when multiplying the baseline rate of ADC by the corresponding OR. This abatement parameter encompasses uncertainties associated with germ viability, infectivity and virulence in natural settings. CONCLUSION The dose-response function for waterborne Giardia risk derived from clinical experiments is consistent with epidemiological data. However, much remains to be learned about key characteristics that may heavily influence quantitative risk assessment results.
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Affiliation(s)
- D Zmirou-Navier
- INSERM-ERI 11, Nancy University Medical School – 9 av de la Forêt de Haye, BP 184 – 54505 Vandoeuvre-les-Nancy Cedex, France
| | | | - Ph Hartemann
- INSERM-ERI 11, Nancy University Medical School – 9 av de la Forêt de Haye, BP 184 – 54505 Vandoeuvre-les-Nancy Cedex, France
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Gow S, Waldner C. An examination of the prevalence of and risk factors for shedding of Cryptosporidium spp. and Giardia spp. in cows and calves from western Canadian cow-calf herds. Vet Parasitol 2006; 137:50-61. [PMID: 16472921 DOI: 10.1016/j.vetpar.2005.05.071] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Accepted: 05/28/2005] [Indexed: 11/22/2022]
Abstract
The primary objectives of this study were to describe the prevalence and risk factors for Cryptosporidium spp. and Giardia spp. infection in cows and calves during the calving season in western Canadian cow-calf herds. Through the calving season of 2002, fresh fecal samples were collected from 560 beef cows and 605 calves in western Canada. Feces were examined for the presence of Cryptosporidium spp. and Giardia spp. using a quantitative sucrose gradient immunoflourescent antibody test. Samples were collected from mature cows on 59 farms and from calves on 100 farms. Only 1.1% (5/560) of the cows were positive for Cryptosporidium spp. whereas 3.1% (19/605) of the calves were positive. Prevalence for Giardia spp. was much higher; Giardia spp. was detected in 17.0% (95/560) of the cow and 22.6% (137/605) of calf fecal samples. Data describing herd management practices, treatment and disease history, age, gender, breed and fecal consistency were gathered to assess potential risk factors associated with shedding. The association between the risk of shedding and average precipitation from December to June and ecological region were also evaluated. Risk factors for infection with Cryptosporidium spp. in either cows or calves could not be evaluated because the multilevel model would not converge due to the relatively low prevalence of the organism in this sample. The prevalence for Giardia spp. was sufficient to explore potential risk factors in both cows and calves. No risk factors were identified for Giardia spp. in beef cows following calving. After the construction of a multivariable model, the only significant predictors for Giardia spp. presence in beef calves was dam age and calf age. Calves born to 2-year-old heifers were 2.3 (95% CI, 1.09-5.06; P = 0.031) times more likely to be shedding Giardia spp. then calves born to cows that were 4-10 years of age. Calves that were 9-18 days of age and calves that were > 18 days of age were 22.4 (95% CI, 5.88-88.18; P < 0.001) and 150 (95% CI, 39.72-603.19; P < 0.001) times more likely, respectively, to be shedding Giardia spp. than calves < or = 4 days of age.
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Affiliation(s)
- Sheryl Gow
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Sask., Canada S7N 5B4.
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Lodder WJ, de Roda Husman AM. Presence of noroviruses and other enteric viruses in sewage and surface waters in The Netherlands. Appl Environ Microbiol 2005; 71:1453-61. [PMID: 15746348 PMCID: PMC1065170 DOI: 10.1128/aem.71.3.1453-1461.2005] [Citation(s) in RCA: 245] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Since virus concentrations in drinking waters are generally below the detection limit, the infectious risk from drinking water consumption requires assessment from the virus concentrations in source waters and removal efficiency of treatment processes. In this study, we estimated from reverse transcription-PCR on 10-fold serially diluted RNA that noroviruses, the most prevalent waterborne gastroenteritis agents, were present at 4 (0.2 to 38) to 4,900 (303 to 4.6 x 10(4)) PCR-detectable units (PDU) per liter of river water (ranges are given in parentheses). These virus concentrations are still high compared with 896 to 7,499 PDU/liter of treated sewage and 5,111 to 850,000 PDU/liter in raw sewage. Sequencing analyses designated human norovirus GGII.4 Lordsdale as the most prevalent strain in the sampling period 1998 to 1999 in both sewage and surface waters. Other GGII strains were also very abundant, indicating that the majority of the virus contamination was derived from urban sewage, although very divergent strains and one animal strain were also detected in the surface and sewage waters. Rotaviruses were also detected in two large rivers (the Maas and the Waal) at 57 to 5,386 PDU/liter. The high virus concentrations determined by PCR may in part be explained by the detection of virus RNA instead of infectious particles. Indeed, reoviruses and enteroviruses that can be cultured were present at much lower levels, of 0.3 to 1 and 2 to 10 PFU/liter, respectively. Assuming 1% of the noroviruses and rotaviruses to be infectious, a much higher disease burden than for other viruses can be expected, not only because of the higher levels but also because of these viruses' higher infectivity and attack rates.
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Affiliation(s)
- W J Lodder
- Microbiological Laboratory for Health Protection, National Institute of Public Health and the Environment, PO Box 1, NL-3720 BA Bilthoven, The Netherlands
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Priest JW, Mehlert A, Arrowood MJ, Riggs MW, Ferguson MAJ. Characterization of a Low Molecular Weight Glycolipid Antigen from Cryptosporidium parvum. J Biol Chem 2003; 278:52212-22. [PMID: 14557271 DOI: 10.1074/jbc.m306835200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cryptosporidium parvum, an Apicomplexan parasite of the mammalian gut epithelium, causes a diarrheal illness in a wide range of hosts and is transmitted by contamination of food or water with oocyst-laden feces from an infected animal. We have identified a glycosylinositol phospholipid from the sporozoite stage of the parasite that is frequently recognized by serum antibodies from human cryptosporidiosis patients. The humoral immune response is dominated by IgG1 subclass antibodies but can also include IgA and IgM antibodies. The glycosylinositol phospholipids were purified by butanol extraction of a Triton X-114-soluble fraction followed by octyl-Sepharose column chromatography and preparative high performance TLC and were shown to include at least 5 species. By using mass spectrometry and radiolabeled neutral glycan analysis, we found that the structure of the dominant glycosylinositol phospholipid antigen contained a C18:0 lyso-acylglycerol, a C16:0-acylated inositol, and an unsubstituted mannose3-glucosamine glycan core. Other diacyl species were also identified, most notably a series of glycosylinositol phospholipids having an acyl-linked C20:0 to C28:0 lipid on the inositol ring. Less abundant species having three acyl-linked fatty acids and species with an additional 1-3 hexoses linked to the mannose core were also observed. We are currently working to determine the role that these glycolipids may play in the development of disease and in the clearance of infection.
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Affiliation(s)
- Jeffrey W Priest
- Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA.
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Gaffield SJ, Goo RL, Richards LA, Jackson RJ. Public health effects of inadequately managed stormwater runoff. Am J Public Health 2003; 93:1527-33. [PMID: 12948975 PMCID: PMC1448005 DOI: 10.2105/ajph.93.9.1527] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES This study investigated the scale of the public health risk from stormwater runoff caused by urbanization. METHODS We compiled turbidity data for municipal treated drinking water as an indication of potential risk in selected US cities and compared estimated costs of waterborne disease and preventive measures. RESULTS Turbidity levels in other US cities were similar to those linked to illnesses in Milwaukee, Wis, and Philadelphia, Pa. The estimated annual cost of waterborne illness is comparable to the long-term capital investment needed for improved drinking water treatment and stormwater management. CONCLUSIONS Although additional data on cost and effectiveness are needed, stormwater management to minimize runoff and associated pollution appears to make sense for protecting public health at the least cost.
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Affiliation(s)
- Stephen J Gaffield
- Office of Children's Health Protection, US Environmental Protection Agency, Washington, DC, USA.
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Davies JM, Mazumder A. Health and environmental policy issues in Canada: the role of watershed management in sustaining clean drinking water quality at surface sources. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2003; 68:273-286. [PMID: 12837256 DOI: 10.1016/s0301-4797(03)00070-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Sustaining clean and safe drinking water sources is increasingly becoming a priority because of global pollution. The means of attaining and maintaining clean drinking water sources requires effective policies that identify, document, and reduce watershed risks. These risks are defined by their potential impact to human health. Health and risk are, therefore, indelibly linked because they are in part defined by each other. Understanding pathogen ecology and identifying watershed sources remains a priority because of the associated acute risks. Surface water quality changes resulting from inputs of human waste, nutrients and chemicals are associated with higher drinking water risks. Nutrient input can increase primary production and the resulting increase of organic matter results in greater disinfection by-product formation or requires greater treatment intensity. Many drinking water disease outbreaks have resulted from breaches in treatment facilities, therefore, even with greater treatment intensity poor source water quality intrinsically has greater associated health risks. Government and international agencies play a critical role in developing policy. The goal of maintaining water supplies whose availability is maximized and risks are minimized (i.e. sustainable) should be a vital part of such policy. Health risks are discussed in the context of a multi-barrier perspective and it is concluded that both passive (protection) and active (prescriptive management) management is necessary for sustainability. Canadian aboriginal water systems, British Columbian water policy and US EPA policies are given as examples. The basis for developing effective policies includes a strong reliance on sound science and effective instrumentation with careful consideration of stakeholders' interests. Only with such directed policies can the future availability of clean drinking water sources be ensured.
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Affiliation(s)
- John-Mark Davies
- Department of Biology, NSERC/IRC Environmental Management of Drinking Water, University of Victoria, PO Box 3020 Stn CSC, Victoria, BC, Canada V8N 3N5.
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Barwick RS, Mohammed HO, White ME, Bryant RB. Prevalence of Giardia spp. and Cryptosporidium spp. on dairy farms in southeastern New York state. Prev Vet Med 2003; 59:1-11. [PMID: 12719012 DOI: 10.1016/s0167-5877(03)00052-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A prevalence study was designed to determine the presence of Cryptosporidium spp. and Giardia spp. in the soil of 37 dairy farms in southeastern New York state. A sampling design was developed and used to collect soil samples from these farms. Areas on the farms which were considered to be potential sources of contamination to the environment were evaluated quantitatively using a multidimensional scale. This scale included factors which could have the potential to contribute to the risk of contamination of the environment with Giardia or Cryptosporidium. In addition, the runoff pathway from these areas was identified and sampling points along that pathway were determined. Using a sampling grid, sampling sites were determined and soil samples collected and analyzed individually for the following: presence of Giardia and Cryptosporidium, pH, gravimetric moisture content, and volumetric moisture content. Out of 782 soil samples, 17% were positive for Cryptosporidium and 4% were positive for Giardia. The pH of the soil ranged from 3.7 to 9.8 with a mean of 7.0. There was a significant association between the pH and the likelihood of detecting Cryptosporidium spp. As the pH increased, the likelihood of detecting an oocyst decreased. Gravimetric moisture content had a mean of 40% and a range from 7 to 86%. There was a significant association between the gravimetric moisture content and the likelihood of detecting Giardia in soil samples.
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Affiliation(s)
- R S Barwick
- Section of Epidemiology, Cornell University, Ithaca, NY 14853, USA
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Gofti-Laroche L, Gratacap-Cavallier B, Demanse D, Genoulaz O, Seigneurin JM, Zmirou D. Are waterborne astrovirus implicated in acute digestive morbidity (E.MI.R.A. study)? J Clin Virol 2003; 27:74-82. [PMID: 12727532 DOI: 10.1016/s1386-6532(02)00130-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND With rotavirus and Norwalk-like viruses, astroviruses are now recognized as important etiologic agents of viral gastroenteritis in all age groups. However, astrovirus is neither routinely screened for in stool samples, nor in environmental samples, and data on the health impact of waterborne astrovirus are lacking. OBJECTIVES To assess the potential impact of astrovirus in drinking water on the incidence of acute digestive conditions (ADC) among a panel of volunteers. STUDY DESIGN The Epidemiology and MIcrobial Risk Assessment (E.MI.R.A.) study combined a daily epidemiological follow-up of digestive morbidity among a panel of 544 volunteers supplied by French public water systems, and a microbiological surveillance of drinking water. Cases of digestive morbidity were collected through weekly telephone calls. The bacterial, virological and parasitic quality of tap water was assessed monthly. Additional samples were collected if the incidence of ADC increased. The relationship between incidence of ADC during a 7-day period centered about the water sampling day and astrovirus RNA prevalence in drinking water was modeled by regression techniques, taking into account several confounders. RESULTS 12% (8/68) of the analyzed water samples were positive for astrovirus, and presence of astrovirus RNA was associated with a significant increased risk of ADC: RR=1.51 (95% CI=[1.17-1.94], P value=0.002). CONCLUSIONS This result suggests a role for waterborne astrovirus in the endemic level of digestive morbidity in the general population. Perhaps astrovirus is a candidate test target for viral surveillance of drinking water.
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Affiliation(s)
- L Gofti-Laroche
- Public Health Laboratory, Grenoble University Medical School, France.
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36
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Gofti-Laroche L, Demanse D, Joret JC, Zmirou D. Health risks and parasitical quality of water. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/j.1551-8833.2003.tb10370.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Khalakdina A, Vugia DJ, Nadle J, Rothrock GA, Colford JM. Is drinking water a risk factor for endemic cryptosporidiosis? A case-control study in the immunocompetent general population of the San Francisco Bay Area. BMC Public Health 2003; 3:11. [PMID: 12689343 PMCID: PMC153519 DOI: 10.1186/1471-2458-3-11] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2002] [Accepted: 03/07/2003] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Cryptosporidiosis, caused by Cryptosporidium, is an enteric illness that has received much attention as an infection of immunocompromised persons as well as in community outbreaks (frequently waterborne). There are, however, no studies of the risk factors for sporadic community-acquired cryptosporidiosis in the immunocompetent US population. We undertook a case-control study in the San Francisco Bay Area as part of a national study sponsored by the Centers for Disease Control and Prevention to ascertain the major routes of transmission for endemic cryptosporidiosis, with an emphasis on evaluating risk from drinking water. METHODS Cases were recruited from a population-based, active surveillance system and age-matched controls were recruited using sequential random-digit dialing. Cases (n = 26) and controls (n = 62) were interviewed by telephone using a standardized questionnaire that included information about the following exposures: drinking water, recreational water, food items, travel, animal contact, and person-to-person fecal contact, and (for adults) sexual practices. RESULTS In multivariate conditional logistic regression analyses no significant association with drinking water was detected. The major risk factor for cryptosporidiosis in the San Francisco Bay Area was travel to another country (matched odds ratio [95% confidence interval]: 24.1 [2.6, 220]). CONCLUSION The results of this study do not support the hypothesis that drinking water is an independent risk factor for cryptosporidiosis among the immunocompetent population. These findings should be used to design larger studies of endemic cryptosporidiosis to elucidate the precise mechanisms of transmission, whether waterborne or other.
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Affiliation(s)
- Asheena Khalakdina
- Division of Public Health Biology and Epidemiology, Centers for Family & Community Health and Occupational & Environmental Health, School of Public Health, University of California, Berkeley, California, USA
| | - Duc J Vugia
- California Emerging Infections Program, Oakland, California, USA
- Division of Communicable Disease Control, California Department of Health Services, Berkeley, California, USA
| | - Joelle Nadle
- California Emerging Infections Program, Oakland, California, USA
| | | | - John M Colford
- Division of Public Health Biology and Epidemiology, Centers for Family & Community Health and Occupational & Environmental Health, School of Public Health, University of California, Berkeley, California, USA
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Barwick RS, Mohammed HO, White ME, Bryant RB. Factors associated with the likelihood of Giardia spp. and Cryptosporidium spp. in soil from dairy farms. J Dairy Sci 2003; 86:784-91. [PMID: 12703614 DOI: 10.3168/jds.s0022-0302(03)73660-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A study was conducted to identify factors associated with the likelihood of detecting Giardia spp. and Cryptosporidium spp. in the soil of dairy farms in a watershed area. A total of 37 farms were visited, and 782 soil samples were collected from targeted areas on these farms. The samples were analyzed for the presence of Cryptosporidium spp. oocysts, Giardia spp. cysts, percent moisture content, and pH. Logistic regression analysis was used to identify risk factors associated with the likelihood of the presence of these organisms. The use of the land at the sampling site was associated with the likelihood of environmental contamination with Cryptosporidium spp. Barn cleaner equipment area and agricultural fields were associated with increased likelihood of environmental contamination with Cryptosporidium spp. The risk of environmental contamination decreased with the pH of the soil and with the score of the potential likelihood of Cryptosporidium spp. The size of the sampling site, as determined by the sampling design, in square feet, was associated nonlinearly with the risk of detecting Cryptosporidium spp. The likelihood of the Giardia cyst in the soil increased with the prevalence of Giardia spp. in animals (i.e., 18 to 39%). As the size of the farm increased, there was decreased risk of Giardia spp. in the soil, and sampling sites which were covered with brush or bare soil showed a decrease in likelihood of detecting Giardia spp. when compared to land which had managed grass. The number of cattle on the farm less than 6 mo of age was negatively associated with the risk of detecting Giardia spp. in the soil, and the percent moisture content was positively associated with the risk of detecting Giardia spp. Our study showed that these two protozoan exist in dairy farm soil at different rates, and this risk could be modified by manipulating the pH of the soil.
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Affiliation(s)
- R S Barwick
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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39
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Aragón TJ, Novotny S, Enanoria W, Vugia DJ, Khalakdina A, Katz MH. Endemic cryptosporidiosis and exposure to municipal tap water in persons with acquired immunodeficiency syndrome (AIDS): a case-control study. BMC Public Health 2003; 3:2. [PMID: 12515584 PMCID: PMC149226 DOI: 10.1186/1471-2458-3-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2002] [Accepted: 01/06/2003] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND In persons with acquired immunodeficiency syndrome (AIDS), Cryptosporidium parvum causes a prolonged, severe diarrheal illness to which there is no effective treatment, and the risk of developing cryptosporidiosis from drinking tap water in non-outbreak settings remains uncertain. To test the hypothesis that drinking tap water was associated with developing cryptosporidiosis, we conducted a matched case-control study among persons with AIDS in San Francisco. METHODS Among patients reported to the San Francisco AIDS Registry from May 1996 through September 1998, we compared patients who developed cryptosporidiosis to those who did not. Cases were individually matched to controls based on age, sex, race/ethnicity, CD4+ T lymphocyte count, date of CD4+ count, and date of case diagnosis. Population attributable fractions (PAFs) were calculated. RESULTS The study consisted of 49 cases and 99 matched controls. In the multivariable analysis with adjustments for confounders, tap water consumption inside and outside the home at the highest exposure categories was associated with the occurrence of cryptosporidiosis (inside the home: odds ratio (OR), 6.76; 95% CI 1.37-33.5, and outside the home: OR 3.16; 95% CI 1.23-8.13). The PAF was 85%; that is, the proportion of cases of cryptosporidiosis in San Francisco AIDS patients attributable to tap water consumption could have been as high as 85%. CONCLUSIONS Although the results from this observational study cannot be considered definitive, until there is more data, we recommend persons with AIDS, especially those with compromised immune systems, consider avoiding tap water.
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Affiliation(s)
- Tomás J Aragón
- Department of Epidemiology and Biostatistics, and of Medicine, University of California, San Francisco, USA
- San Francisco Department of Public Health, City and County of San Francisco, USA
| | - Suzanne Novotny
- San Francisco Department of Public Health, City and County of San Francisco, USA
| | - Wayne Enanoria
- Division of Public Health Biology and Epidemiology, School of Public Health, University of California, Berkeley, California, USA
- San Francisco Department of Public Health, City and County of San Francisco, USA
| | - Duc J Vugia
- California Emerging Infections Program, Oakland, California, USA
- Division of Communicable Disease Control, California Department of Health Services, Berkeley, California, USA
| | - Asheena Khalakdina
- Division of Public Health Biology and Epidemiology, School of Public Health, University of California, Berkeley, California, USA
- San Francisco Department of Public Health, City and County of San Francisco, USA
| | - Mitchell H Katz
- Department of Epidemiology and Biostatistics, and of Medicine, University of California, San Francisco, USA
- San Francisco Department of Public Health, City and County of San Francisco, USA
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40
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Hellard ME, Sinclair MI, Dharmage SC, Bailey MJ, Fairley CK. The rate of gastroenteritis in a large city before and after chlorination. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2002; 12:355-360. [PMID: 12590783 DOI: 10.1080/0960312021000056384] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
There is conflicting evidence about the contribution of drinking water to endemic community gastroenteritis in water supplies which meet conventional microbiological standards with some studies reporting associations between drinking water and endemic disease and others finding no evidence that water is implicated in disease. This study reports the results of an ecological study investigating the effect on community gastroenteritis of chlorinating a city of over 3 million people in the mid 1970s. Prior to chlorination faecal coliforms were regularly identified in the water. Admissions for gastroenteritis and attendances to the Emergency Department of the Royal Children's Hospital, Melbourne's major children's hospital, were measured between 1974 and 1980 inclusive and the influence of chlorination on rates of gastroenteritis was examined. No statistically significant difference was found in the number of admissions or emergency department visits before and after chlorination of the water supply. The study highlights the need for caution when interpreting the relationships between drinking water and gastroenteritis. The result suggests that water was not a dominant contributor to the burden of gastrointestinal disease in the community despite faecal coliforms being present in the water supply. It indicates the need for caution when attributing significant illness to drinking water when there have been only small changes in water quality without first stringently reviewing the studies methodology and understanding their limitations.
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Affiliation(s)
- M E Hellard
- Department of Public Health, University of Melbourne, Australia
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41
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Krewski D, Balbus J, Butler-Jones D, Haas C, Isaac-Renton J, Roberts KJ, Sinclair M. Managing health risks from drinking water--a report to the Walkerton inquiry. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2002; 65:1635-1823. [PMID: 12433311 DOI: 10.1080/00984100290071711] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
- Daniel Krewski
- McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Ontario, Canada.
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Abstract
Cryptosporidium was first recognized in humans in 1976 and came to prominence in the 1980s and 1990s as a cause of severe diarrheal illness in patients with AIDS. Its hardy, chlorine-resistant oocysts, tiny size, low infectious dose, fully infectious development when shed and zoonotic potential make it a threat in drinking and recreational water, contaminated food, day care centers, hospitals, and in persons with exposure to animals or unsanitary conditions, with potentially huge, long-term impact in malnourished children, as reviewed herein.
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Affiliation(s)
- Rebecca A Dillingham
- Division of Geographic and International Medicine, University of Virginia School of Medicine, Health Sciences Center, P.O. Box 801379, Charlottesville, VA 22908-1379, USA
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Ferreira MS, Borges AS. Some aspects of protozoan infections in immunocompromised patients- a review. Mem Inst Oswaldo Cruz 2002; 97:443-57. [PMID: 12118272 DOI: 10.1590/s0074-02762002000400001] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Protozoa are among the most important pathogens that can cause infections in immunocompromised hosts. These microorganisms particularly infect individuals with impaired cellular immunity, such as those with hematological neoplasias, renal or heart transplant patients, patients using high doses of corticosteroids, and patients with acquired immunodeficiency syndrome. The protozoa that most frequently cause disease in immunocompromised patients are Toxoplasma gondii, Trypanosoma cruzi, different Leishmania species, and Cryptosporidium parvum; the first two species cause severe acute meningoencephalitis and acute myocarditis, Leishmania sp. causes mucocutaneous or visceral disease, and Cryptosporidium can lead to chronic diarrhea with hepatobiliary involvement. Various serological, parasitological, histological and molecular methods for the diagnosis of these infections are currently available and early institution of specific therapy for each of these organisms is a basic measure to reduce the morbidity and mortality associated with these infections.
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Affiliation(s)
- Marcelo Simão Ferreira
- Faculdade de Medicina, Universidade Federal de Uberlândia, Uberlândia, MG, 38400-027, Brasil.
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Poullis DA, Attwell RW, Powell SC. An evaluation of waterborne disease surveillance in the European Union. REVIEWS ON ENVIRONMENTAL HEALTH 2002; 17:149-161. [PMID: 12222740 DOI: 10.1515/reveh.2002.17.2.149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Surveillance systems to inform controls for waterborne disease (WBD) are important for the protection of public health. Member States of the European Union (EU) will soon be required to implement Directives and the Protocol on Water and Health for controlling WBD. The investigation reported here considers the consistency of surveillance systems across the EU. Eleven EU member states participated in a survey to determine the nature and range of practices used for monitoring WBD. Some WBD are notifiable in most countries surveyed, others are notifiable only in one country. Non-notifiable WBD are routinely monitored in five countries. Surveillance schemes are inconsistent, and the variable mandatory reporting among the Member States allows many WBD cases to remain unidentified. Nine replying countries had no legal definition for WBD outbreak. No country requires the reporting of anti-diarrhea medication sales for detecting outbreaks.
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Affiliation(s)
- Dinos A Poullis
- The Centre for Health and Risk Management, Department of Biological Sciences, Manchester Metropolitan University, United Kingdom
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45
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Craun GF, Frost FJ. Possible information bias in a waterborne outbreak investigation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2002; 12:5-15. [PMID: 11970811 DOI: 10.1080/09603120120110013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Although an investigation of a cryptosporidiosis outbreak in 1994 in Clark County, Nevada, concluded that illness was associated with consumption of municipal water, no water treatment deficiencies or breakdowns and no water quality changes were discovered during the investigation. We evaluated the strength of the evidence for waterborne transmission and conducted a sensitivity analysis to define the limitations of the epidemiological data. Our analyses suggest a spurious inference of waterborne transmission might be due to differential misclassification bias. If exposure and disease status were incorrectly classified for a relatively small number of study participants, findings of the investigation would be interpreted differently. We offer this example to illustrate the importance of assessing the stability of a relative risk estimate and effect of possible biases during an outbreak investigation.
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Affiliation(s)
- G F Craun
- Gunther F. Craun & Associates, 101 West Frederick Street, Suite 205, Staunton, VA 24401, USA
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46
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Abstract
Cryptosporidium parvum is a protozoan parasite that infects the epithelial cells of the small intestine causing diarrheal illness in humans. Cryptosporidium has a worldwide distribution and is considered an emerging zoonosis. Despite intensive efforts to develop workable experimental models, and the evaluation of over 200 chemotherapeutic agents, adequate therapies to clear the host of these parasites are still lacking. The reasons for the lack of drug efficacy are probably manifold and may include the unusual location of the parasite in the host cell, distinct structural and biochemical composition, or its ability to either block import or rapidly efflux drug molecules. Understanding some of the basic mechanisms by which drugs are transported to the parasite and identifying unique targets is a first step in developing effective therapeutic agents.
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Affiliation(s)
- Jan R Mead
- Atlanta Veterans Medical Center and Department of Pediatrics, Emory University, 1670 Clairmont Road, Decatur, GA 30033, USA.
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47
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Field AS. Light microscopic and electron microscopic diagnosis of gastrointestinal opportunistic infections in HIV-positive patients. Pathology 2002; 34:21-35. [PMID: 11902443 DOI: 10.1080/00313020120111230] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The surgical pathologist is expected to recognise gastrointestinal opportunistic infections in biopsies from HIV-positive patients, and patients immunocompromised iatrogenically by cancer therapy, steroid treatment and transplantation immunosuppression regimes. This review article presents the diagnostic features in gastrointestinal biopsies of microsporidia, cyclospora, isospora, cryptosporidia, mycobacteria, adenovirus, enteropathogenic bacteria, cryptococcus and leishmania. All of these infections have been diagnosed at our hospital in Sydney, Australia, since the AIDS epidemic began. A protocol for the examination and assessment of these gastrointestinal biopsies is presented and discussed.
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Affiliation(s)
- Andrew S Field
- Department of Anatomical Pathology, St Vincent's Hospital, Darlinghurst, NSW, Australia.
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48
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Teunis PFM, Chappell CL, Okhuysen PC. Cryptosporidium dose response studies: variation between isolates. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2002; 22:175-183. [PMID: 12017359 DOI: 10.1111/0272-4332.00014] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The infectivity of three different isolates of the waterborne protozoan parasite Cryptosporidium parvum has been tested in human feeding studies. These three isolates (Iowa, TAMU, and UCP) have different ID50s, indicating substantial variation in their infectivity for humans. This finding is of great importance for quantitative risk assessment as it provides strong evidence for heterogeneity in infectivity among isolates of the same species.
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Affiliation(s)
- Peter F M Teunis
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
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49
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Kosek M, Alcantara C, Lima AA, Guerrant RL. Cryptosporidiosis: an update. THE LANCET. INFECTIOUS DISEASES 2001; 1:262-9. [PMID: 11871513 DOI: 10.1016/s1473-3099(01)00121-9] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cryptosporidiosis was recognised in human beings in 1976, and was prominent in the 1980s and 1990s as a cause of severe diarrhoeal illness in patients with AIDS. It is now additionally recognised as a major cause of waterborne diarrhoeal illness in developed regions, and as a pathogen with long-term effect on childhood growth and development in impoverished areas. This update focuses on recent changes in our understanding of the taxonomy of cryptosporidium, its epidemiology, effects, pathogenesis, diagnosis, and treatment.
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Affiliation(s)
- M Kosek
- Division of Geographic and International Medicine, University of Virginia, Charlottesville 22908-1379, USA
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50
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Hassl A, Benyr G, Sommer R. Occurrence of Cryptosporidium sp. oocysts in fecal and water samples in Austria. Acta Trop 2001; 80:145-9. [PMID: 11600093 DOI: 10.1016/s0001-706x(01)00169-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Oocysts of Cryptosporidium spp. were detected and differentiated by a modular arranged gene amplification procedure in various samples, mostly human stool, feces of herpetotaxa, and water, in different locations of South and Eastern Austria. Cryptosporidium parvum was found in stool samples of immunocompromised persons, in reptile feces, and in water samples. The presence of Cryptosporidium in an area is probably associated with high human population densities since water from protected sources in sparsely inhabited areas is rarely contaminated.
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Affiliation(s)
- A Hassl
- Micro-Biology Consult Andreas Hassl, Ameisgasse 63/4/12, A-1140 Vienna, Austria.
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