| epidemiology of hemolytic-uremic syndrome in canadian children from 1986 to 1988. the canadian pediatric kidney disease reference centre. | to define the epidemiologic features of childhood hemolytic-uremic syndrome (hus) on a national level in canada, to determine the proportion of patients in whom escherichia coli o157:h7 was isolated from stools, and to examine risk factors for more severe hus. | 1991 | 1861207 |
| outbreak of escherichia coli o157:h7 in a nursing home--ontario. | | 1990 | 2189574 |
| bovine reservoir for verotoxin-producing escherichia coli o157:h7. | | 1987 | 2879192 |
| a family outbreak of hemolytic-uremic syndrome associated with verotoxin-producing escherichia coli serotype o157:h7. | all five siblings (three boys and two girls, aged 1.5-9 years) in a family developed hemolytic-uremic syndrome associated with verotoxin-producing escherichia coli o157:h7 at a lakeside vacation cottage during the fall of 1985. all five were hospitalized and made a full recovery. both parents remained asymptomatic, and neither had evidence of this infection. in four children who were investigated prospectively, free verotoxin was still detectable in the stools for between 3 and 7 weeks. the prod ... | 1988 | 3153052 |
| laboratory investigation of outbreak of hemorrhagic colitis caused by escherichia coli o157:h7. | a severe outbreak of hemorrhagic colitis occurred in london, ontario, during the month of september 1985. a total of 55 residents and 18 employees of a nursing home developed diarrhea, and 17 residents (age range, 78 to 99 years) died. specimens from 38 patients, 37 employees and contacts, and 10 autopsies were investigated for all enteric pathogens. specimens were also planted on macconkey-sorbitol agar. fecal extracts were tested on vero cells for cytotoxin (fvt). escherichia coli isolates wer ... | 1987 | 3298310 |
| a severe outbreak of escherichia coli o157:h7--associated hemorrhagic colitis in a nursing home. | in september 1985, an outbreak of escherichia coli o157:h7 enteritis affected 55 of 169 residents and 18 of 137 staff members at a nursing home. the outbreak was characterized by two phases: a primary wave whose source was probably a contaminated sandwich meal and a secondary wave compatible with person-to-person transmission of infection. among the elderly residents, the incubation period was 4 to 9 days (mean, 5.7 +/- 1.2). older age and previous gastrectomy increased the risk of acquiring the ... | 1987 | 3317047 |
| frequency of escherichia coli o157:h7 isolation from stool specimens. | during a 6-month period, 7252 faeces specimens were examined for escherichia coli serotype o157:h7. forty-nine specimens (0.7%) from 19 patients yielded this organism. escherichia coli o157:h7 was the third most frequently isolated bacterial pathogen, following campylobacter jejuni and (or) salmonella sp. although regional variation between laboratories determined whether campylobacter jejuni or salmonella was the primary bacterial pathogen isolated, e. coli o157:h7 was consistently isolated mor ... | 1987 | 3319115 |
| evidence of direct transmission of escherichia coli o157:h7 infection between calves and a human--ontario. | | 1994 | 8038753 |
| hospital outbreak of escherichia coli o157:h7 associated with a rare phage type--ontario. | | 1997 | 9094790 |
| persistence of escherichia coli o157:h7 in dairy cattle and the dairy farm environment. | the persistence of escherichia coli o157:h7 in cattle and the farm environment was investigated on eight ontario dairy farms positive for e. coli o157:h7 in a longitudinal study commenced one year previously. faecal samples from cows, calves, humans, cats, rodents, wild birds, a composite fly sample and numerous composite and individual environmental samples were cultured and tested for verotoxin-producing e. coli (vtec). vtec isolates were serotyped and e. coli o157:h7 isolates were phage typed ... | 1997 | 9363025 |
| escherichia coli o157:h7 diarrhoea associated with well water and infected cattle on an ontario farm. | a 16-month old female child living on an ontario dairy farm was taken to hospital suffering from bloody diarrhoea. escherichia coli o157:h7 was isolated from her stool. initial tests of well water samples were negative for e. coli by standard methods but culture of selected coliform colonies on sorbitol-macconkey agar led to isolation of e. coli o157:h7. e. coli o157:h7 was also isolated from 63% of cattle on the farm. the e. coli o157:h7 isolates from the child, the water and the cattle were ph ... | 1998 | 9528813 |
| temporal and geographical distributions of reported cases of escherichia coli o157:h7 infection in ontario. | the distribution of 3001 cases of verocytotoxigenic escherichia coli (vtec) reported in the province of ontario, canada, were examined to describe the magnitude of this condition geographically and to evaluate the spatial relationship between livestock density and human vtec incidence using a geographical information system. incidence of vtec cases had a marked seasonal pattern with peaks in july. areas with a relatively high incidence of vtec cases were situated predominantly in areas of mixed ... | 1999 | 10355782 |
| an outbreak of escherichia coli o157:h7 infection associated with unpasteurized non-commercial, custom-pressed apple cider--ontario, 1998. | | 1999 | 10448225 |
| molecular typing methods to investigate transmission of escherichia coli o157:h7 from cattle to humans. | the utility of phage typing, pulsed-field gel electrophoresis (pfge), and plasmid profile analysis was compared, to differentiate between canadian escherichia coli o157:h7 strains of human (n = 27) and cattle (n = 24) origin. the diversity indices for phage typing, plasmid analysis and pfge were 0.85, 0.69 and 0.93, respectively. pfge and phage typing were also applied to study the role of direct transmission of e. coli o157:h7 from cattle to humans on isolates collected from two separate farm o ... | 1999 | 10487637 |
| illness outbreak associated with escherichia coli o157:h7 in genoa salami. e. coli o157:h7 working group. | an outbreak of escherichia coli o157:h7 infection was identified in the spring of 1998, with a 7-fold increase in the number of laboratory-confirmed e. coli o157:h7 cases in southern ontario. this prompted an intensive investigation by local, provincial and federal public health officials. | 2000 | 10834043 |
| evaluation of the reveal and safepath rapid escherichia coli o157 detection tests for use on bovine feces and carcasses. | the reveal (neogen corp., lansing, mich.) and safepath (safepath laboratories llc, st. paul, minn.) tests were evaluated for their performance as beef fecal and beef carcass escherichia coli o157:h7 monitoring tests. agreement between these tests and a reference test system was determined using naturally contaminated bovine feces and beef carcasses. the reference system utilized immunomagnetic separation with plating onto cefixime, tellurite, sorbitol macconkey agar, followed by colony testing u ... | 2000 | 10914650 |
| escherichia coli o157:h7. | | 2000 | 10934989 |
| estimation of the under-reporting rate for the surveillance of escherichia coli o157:h7 cases in ontario, canada. | two models estimating the proportion of escherichia coli o157:h7 cases not reported in the ontario notifiable diseases surveillance system are described. the first model is a linear series of adjustments in which the total number of reported cases is corrected by successive underreporting coefficients. the structure of the second model is based on a relative difference in the proportion of e. coli o157:h7 cases which are hospitalized between the surveillance database and the underlying populatio ... | 2000 | 11057957 |
| drinking water contamination in walkerton, ontario: positive resolutions from a tragic event. | in may 2000, escherichia coli o157:h7 and campylobacter jejuni contaminated the drinking water supply in walkerton, ontario. seven people died and over 2,000 were ill as a result. the ontario provincial government set up a judicial inquiry into the circumstances surrounding the outbreak and also moved quickly to introduce a new drinking water regulation that incorporated some significant requirements for drinking water providers. the inquiry itself was in three parts: (a) part 1 related to the e ... | 2003 | 12638997 |
| a socio-ecological autopsy of the e. coli o157:h7 outbreak in walkerton, ontario, canada. | the socio-political context of modern environmental health disasters tends to be defined as being outside the scope of official public health and epidemiological investigations into the causes of such disasters. on the other hand, popular accounts of these disasters tend to focus exclusively on the role of particular individuals and/or political actors, while minimizing the role of ecological factors. it is argued that an exclusive focus on either set of causal factors gives an incomplete or dis ... | 2004 | 15081208 |
| assessing levels of pathogenic contamination in a heavily impacted river used as a drinking-water source. | this paper describes initial results from a research program that aims to gain greater understanding of sources of pathogens and the environmental factors that influence their survival and transport in watersheds. an additional goal is to enhance the ability to predict potential levels of pathogenic microorganisms arriving at drinking-water treatment plant intakes. the objectives will be supported by an intensive monitoring program examining the temporal and spatial variability of pathogens in a ... | 2004 | 15371219 |
| heavy rainfall and waterborne disease outbreaks: the walkerton example. | recent research indicates that excessive rainfall has been a significant contributor to historical waterborne disease outbreaks. the meteorological service of canada, environment canada, provided an analysis and testimony to the walkerton inquiry on the excessive rainfall events, including an assessment of the historical significance and expected return periods of the rainfall amounts. while the onset of the majority of the walkerton, ontario, escherichia coli o157:h7 and campylobacter outbreak ... | 2004 | 15371222 |
| syndromic surveillance of gastrointestinal illness using pharmacy over-the-counter sales. a retrospective study of waterborne outbreaks in saskatchewan and ontario. | to ascertain if monitoring over-the-counter (otc) drug sales could provide a timely syndromic surveillance method of detecting outbreaks of gastrointestinal illness. | 2004 | 15622795 |
| use of the oxford multilocus sequence typing protocol and sequencing of the flagellin short variable region to characterize isolates from a large outbreak of waterborne campylobacter sp. strains in walkerton, ontario, canada. | the walkerton (ontario, canada) outbreak of waterborne escherichia coli o157:h7 and campylobacter jejuni was quite limited in both space and time, making it a good model for exploring the utility of different typing and subtyping methods for the characterization of relationships among isolates of these organisms. we have extended previous work with these organisms through analysis by the oxford multilocus sequence typing (mlst) and the flagellin short variable region (fla-svr) sequencing methods ... | 2005 | 15872226 |
| risk of hypertension and reduced kidney function after acute gastroenteritis from bacteria-contaminated drinking water. | the long-term health consequences of acute bacterial gastroenteritis remain uncertain. we studied the risk of hypertension and reduced kidney function after an outbreak of acute gastroenteritis due to contamination of a regional drinking water supply with escherichia coli o157:h7 and campylobacter species. | 2005 | 15923490 |
| the walkerton health study. | the contamination of the walkerton, ontario, municipal water with e. coli o157:h7 and campylobacter in may 2000 resulted in at least 2,300 cases of gastrointestinal illness. there were 28 confirmed cases of hemolytic uremic syndrome, the most severe kidney complication. the provincial ministry of health and long-term care determined that a study needed to be conducted on the long-term health effects associated with drinking the contaminated water. the walkerton health study, a seven-year project ... | 2005 | 16035513 |
| a gradient of acute gastroenteritis was characterized, to assess risk of long-term health sequelae after drinking bacterial-contaminated water. | a municipal water system became contaminated with escherichia coli o157:h7 and campylobacter spp. beginning 2 years after an outbreak, all residents from the region were invited to participate in a cohort study assessing the risk of long-term sequelae. we aimed to develop a method to grade the accuracy and severity of self-reported acute symptoms. | 2006 | 16549265 |
| incidence and epidemiology of irritable bowel syndrome after a large waterborne outbreak of bacterial dysentery. | postinfectious irritable bowel syndrome (pi-ibs) is a common clinical phenomenon. to better define its incidence and epidemiology, a large cohort study was initiated after the contamination of a municipal water supply led to a large outbreak of acute escherichia coli 0157:h7 and campylobacter jejuni gastroenteritis. | 2006 | 16890598 |
| hydrologic modeling of pathogen fate and transport. | a watershed-scale fate and transport model has been developed for escherichia coli and several waterborne pathogens: cryptosporidiumspp., giardiaspp., campylobacter spp, and e. coli o157:h7. the objectives were to determine the primary sources of pathogenic contamination in a watershed used for drinking water supply and to gain a greater understanding of the factors that most influence their survival and transport. to predict the levels of indicator bacteria and pathogens in surface water, an ex ... | 2006 | 16913133 |
| outbreak of escherichia coli 0157:h7 infections associated with consumption of beef donair. | the calgary health region identified an outbreak of escherichia coli 0157:h7 infection in september 2004 following a fourfold increase in laboratory reports. clinical isolates were indistinguishable by pulsed-field gel electrophoresis (pfge), and the pfge pattern was unique in north america. most affected individuals reported beef donair consumption in 10-day food histories. we conducted a matched case-control study, inspected the implicated food premises, and conducted a traceback investigation ... | 2007 | 17612080 |
| pathogen and indicator variability in a heavily impacted watershed. | water samples were collected from 36 locations within the grand river watershed, in southwestern ontario, canada from july 2002 to december 2003 and were analyzed for total coliforms, fecal coliforms, escherichia coli, escherichia coli o157:h7, and thermophilic campylobacter spp. a subset of samples was also analyzed for cryptosporidium spp., giardia spp., culturable human enteric viruses, and clostridium perfringens. storm and snowmelt events were sampled at two locations including a drinking w ... | 2007 | 17674573 |
| arthritis risk after acute bacterial gastroenteritis. | reactive arthritis (rea) may occur from bacterial gastroenteritis. we studied the risk of arthritis after an outbreak of escherichia coli o157:h7 and campylobacter species within a regional drinking water supply to examine the relationship between the severity of acute diarrhoea and subsequent symptoms of arthritis. | 2008 | 18184664 |
| albuminuria and estimated gfr 5 years after escherichia coli o157 hemolytic uremic syndrome: an update. | knowledge of the long-term prognosis of patients with diarrhea-associated hemolytic uremic syndrome (hus) is important for patient counseling and follow-up. estimates in the literature are highly variable, and previous studies did not use a healthy control group to establish outcomes attributable to hus. | 2008 | 18295059 |
| genotypic characterization and prevalence of virulence factors among canadian escherichia coli o157:h7 strains. | in this study, the association between genotypic and selected phenotypic characteristics was examined in a collection of canadian escherichia coli o157:h7 strains isolated from humans and cattle in the provinces of alberta, ontario, saskatchewan, and quebec. in a subset of 69 strains selected on the basis of specific phage types (pts), a strong correlation between the lineage-specific polymorphism assay (lspa6) genotype and pt was observed with all strains of pts 4, 14, 21, 31, 33, and 87 belong ... | 2008 | 18487402 |
| screening policies for daycare attendees: lessons learned from an outbreak of e. coli o157:h7 in a daycare in waterloo, ontario. | control measures for enteric outbreaks in child care settings frequently include screening by stool cultures from symptomatic children only. we present evidence from an investigation of escherichia coli (e. coli) o157:h7 in a daycare in waterloo, ontario to support implementation of a mandatory screening policy for all children during an outbreak. | 2008 | 18767271 |
| relationship between escherichia coli o157:h7 and diabetes mellitus. | ingestion of escherichia coli o157:h7 can cause a spectrum of acute illness, ranging from overt hemolytic-uremic syndrome (hus), to gastroenteritis with bloody diarrhea, to no symptoms. this organism has been responsible for dozens of outbreaks of gastroenteritis and hus in industrialized nations, and thus is a major public health concern. although the acute effects of e. coli o157:h7 ingestion are well understood, the long-term complications are less well known. here, we review the biological a ... | 2009 | 19180134 |
| risk of pregnancy-related hypertension within five years of exposure to bacteria-contaminated drinking water. | exposure to escherichia coli o157:h7 may result in subclinical kidney injury manifesting as hypertension during pregnancy. we evaluated the risk of pregnancy-related hypertension (prh) among previously healthy females from the walkerton health study, canada (2002-6), who conceived within five years of exposure to bacteria-contaminated drinking water. ontario ministry of health antenatal forms were used to determine outcomes and risk factors. prh was defined as any systolic or diastolic blood pre ... | 2009 | 19180135 |
| seasonal relationships among indicator bacteria, pathogenic bacteria, cryptosporidium oocysts, giardia cysts, and hydrological indices for surface waters within an agricultural landscape. | the south nation river basin in eastern ontario, canada is characterized by mixed agriculture. over 1600 water samples were collected on a bi-weekly basis from up to 24 discrete sampling sites on river tributaries of varying stream order within the river basin between 2004 and 2006. water samples were analyzed for: densities of indicator bacteria (escherichia coli, clostridium perfringens, enterococci, total and fecal coliforms), the presence of pathogenic bacteria (listeria monocytogenes, e. co ... | 2009 | 19339033 |
| risk factors associated with escherichia coli o157:h7 in ontario beef cow-calf operations. | the aim of this study was to identify farm management factors associated with the prevalence of escherichia coli o157:h7 among cattle in ontario beef cow-calf operations. a total of 119 cow-calf operations with more than 50 cows in southern ontario were visited between june and december 2002. from each farm, 65 fresh fecal samples were collected and cultured for e. coli o157:h7. colonies of e. coli o157:h7 were isolated using immunomagnetic separation and standard microbiological techniques. fin ... | 2009 | 19692131 |
| timing and utility of ultrasound in diarrhea-associated hemolytic uremic syndrome: 7-year experience of a large tertiary care hospital. | the authors reviewed the clinical, laboratory, and imaging data from cases of diarrhea-associated hemolytic uremic syndrome (hus d+), diagnosed at our institution, from 2001 to 2008. the timing and utility of ultrasonographic features of hus d+ were analyzed. the aim of the study was to determine factors that could aid in the early diagnosis of this disease. a total of 13 children with hus d+ were identified out of 23 patients with hus diagnosed during this time period. evidence of escherichia c ... | 2010 | 20075028 |
| an outbreak of acute bacterial gastroenteritis is associated with an increased incidence of irritable bowel syndrome in children. | acute bacterial gastroenteritis is associated with subsequent post-infectious irritable bowel syndrome (pi-ibs) in adults. less is known about this relationship in children. in may 2000, contamination of municipal water by escherichia coli 0157:h7 and campylobacter species caused a large outbreak of acute gastroenteritis in walkerton, ontario. we assessed this association among a cohort of children enrolled in the walkerton health study (whs). | 2010 | 20179687 |
| long term risk for hypertension, renal impairment, and cardiovascular disease after gastroenteritis from drinking water contaminated with escherichia coli o157:h7: a prospective cohort study. | to evaluate the risk for hypertension, renal impairment, and cardiovascular disease within eight years of gastroenteritis from drinking water contaminated with escherichia coli o157:h7 and campylobacter. | 2010 | 21084368 |
| associations among pathogenic bacteria, parasites, and environmental and land use factors in multiple mixed-use watersheds. | over a five year period (2004-08), 1171 surface water samples were collected from up to 24 sampling locations representing a wide range of stream orders, in a river basin in eastern ontario, canada. water was analyzed for cryptosporidium oocysts and giardia cyst densities, the presence of salmonella enterica subspecies enterica, campylobacter spp., listeria monocytogenes, and escherichia coli o157:h7. the study objective was to explore associations among pathogen densities/occurrence and objecti ... | 2011 | 21889781 |
| pork implicated in a shiga toxin-producing escherichia coli o157:h7 outbreak in ontario, canada. | to describe an outbreak of shiga toxin-producing escherichia coli (stec) o157:h7 infection following a four-day family gathering in ontario. this is the first published account of a stec o157 outbreak in canada linked to consumption of pork. | 2012 | 23617981 |
| cardiovascular disease after escherichia coli o157:h7 gastroenteritis. | escherichia coli o157:h7 is one cause of acute bacterial gastroenteritis, which can be devastating in outbreak situations. we studied the risk of cardiovascular disease following such an outbreak in walkerton, ontario, in may 2000. | 2013 | 23166291 |
| spatiotemporal analysis of cryptosporidium species/genotypes and relationships with other zoonotic pathogens in surface water from mixed-use watersheds. | nearly 690 raw surface water samples were collected during a 6-year period from multiple watersheds in the south nation river basin, ontario, canada. cryptosporidium oocysts in water samples were enumerated, sequenced, and genotyped by detailed phylogenetic analysis. the resulting species and genotypes were assigned to broad, known host and human infection risk classes. wildlife/unknown, livestock, avian, and human host classes occurred in 21, 13, 3, and <1% of sampled surface waters, respective ... | 2012 | 23124241 |
| food safety issues and information needs: an online survey of public health inspectors. | in the study described in this article, the authors investigated the perceptions and needs of public health inspectors (phis) in the province of ontario, canada, with regard to food safety issues and information resources. a cross-sectional online survey of 239 ontario phis was conducted between april and june 2009. questions pertained to their perceptions of key food safety issues and foodborne pathogens, knowledge confidence, available resources, and resource needs. all respondents rated time- ... | 2012 | 22708204 |
| quantitative multi-year elucidation of fecal sources of waterborne pathogen contamination in the south nation river basin using bacteroidales microbial source tracking markers. | over a seven-year period (2004-2010) 1095 water samples were obtained from the south nation river basin at multiple watershed monitoring sites (ontario, canada). real-time pcr using bacteroidales specific markers was used to identify the origin (human (10% prevalence), ruminant (22%), pig (~2%), canada goose (4%) and muskrat (7%)) of fecal pollution. in parallel, the distribution of fecal indicator bacteria and waterborne pathogens (cryptosporidium oocysts, giardia cysts, escherichia coli o157:h ... | 2013 | 23497974 |