Investigating the association between socioeconomic and agricultural risk factors and the incidence of Salmonella Heidelberg and Salmonella Typhimurium in Ontario in 2015: A multi-level ecological approach.

The incidence of salmonellosis, and other enteric zoonotic diseases, has been associated with various food and environmental exposures and socioeconomic factors. Increasingly, there is interest in exploring differences among serotypes of Salmonella to better inform public health prevention efforts. Consequently, we investigated whether rates of Salmonella Heidelberg and Typhimurium in Ontario communities in 2015 were influenced by household characteristics, agricultural factors, and the presence of meat plants.

ATQ: alert time quality, an evaluation metric for assessing timely epidemic detection models within a school absenteeism-based surveillance system.

Background: Wellington-Dufferin-Guelph Public Health (WDGPH) has conducted an absenteeism-based influenza surveillance program in the WDG region of Ontario, Canada since 2008, using a 10% absenteeism threshold to raise an alert for the implementation of mitigating measures. A recent study indicated that model-based alternatives, such as distributed lag seasonal logistic regression models, provided improved alerts for detecting an upcoming epidemic. However model evaluation and selection was primarily based on alert accuracy, measured by the false alert rate (FAR), and failed to optimize timeliness.

Exploring the geographical distribution of human cryptosporidiosis in Southern Ontario from 2011 to 2014.

Cryptosporidium is a protozoan parasite of increasing global public health concern because of its ability to cause disease in both humans and animals through contaminated food and water supplies. In Canada, most human cryptosporidiosis cases are due to Cryptosporidium hominis; however, the presence of zoonotic Cryptosporidium parvum has been observed. Since 2005, the incidence of cryptosporidiosis in Ontario has been consistently higher than the national average; however, it is not understood why, suggesting an incomplete understanding of the pathogen's ecology, epidemiology and transmission pathways.

Detection of spatial and spatio-temporal Salmonella Heidelberg and Salmonella Typhimurium human case clusters focused around licensed abattoirs in Ontario in 2015, and their potential relation to known outbreaks.

Salmonellosis is one of several zoonotic diseases for which individuals with occupational animal contact, including abattoir workers, are at an increased risk. If meat is contaminated during slaughter, this can increase the risk of enteric illness for consumers. In this study, we investigated whether reported cases of Salmonella Heidelberg and Typhimurium were clustered around abattoirs in Ontario in 2015 and whether there was any evidence (laboratory/exposure) to suggest an abattoir at the centre of a cluster might be the source of exposure.

Good times bad times: Automated forecasting of seasonal cryptosporidiosis in Ontario using machine learning.

Background: The rise of big data and related predictive modelling based on machine learning algorithms over the last two decades have provided new opportunities for disease surveillance and public health preparedness. Big data come with the promise of faster generation of and access to more precise information, potentially facilitating predictive precision in public health ("precision public health"). As an example, we considered forecasting of the future course of the monthly cryptosporidiosis incidence in Ontario.

Detection of spatial, temporal and space-time Salmonella Heidelberg and Salmonella Typhimurium clusters in Ontario in 2015, and comparisons to known outbreaks.

Purpose: Salmonellosis is one of several reportable diseases in Ontario (ON). Two or more cases of the same serotype that are linked to a common exposure or related to one another in time and/or space are considered a potential outbreak. While laboratory data can help to determine the molecular relatedness of cases, results may take up to several weeks.

A case-case study comparing the individual risk factors and symptomatology of Salmonella Heidelberg and Salmonella Typhimurium in Ontario in 2015, following implementation of the Ontario Investigation Tools.

Salmonella Heidelberg and Salmonella Typhimurium are among the most common serotypes responsible for human salmonellosis in Ontario. Introduction of the Ontario Investigation Tools (OIT) in 2014 allowed for standardized case investigation and reporting. This study compared the risk factors and symptomatology for sporadic S.

Examining the factors related to bacteriological testing of private wells in Southern Ontario.

The incidence of infectious waterborne disease in Canada continues to be a public health issue and can be associated with the source of drinking water. Millions of Canadians relying on unregulated private well water are at increased risk of disease. This study examined relationships between well and owner characteristics and the frequency of microbial testing of private wells in two southern-Ontario counties.

Exploring the geographical distribution of cryptosporidiosis in the cattle population of Southern Ontario, Canada, 2011-2014.

Cryptosporidiosis is an infectious disease of relevance to the cattle industry. The southern region of the Canadian province of Ontario is characterised by widespread cattle farming that is a key contributor to the Canadian dairy industry. Given Ontario's key role in the Canadian dairy industry and the potential impact that cryptosporidiosis can have on cattle operations, identifying areas of increased risk for bovine cryptosporidiosis is important.

Methods for detecting seasonal influenza epidemics using a school absenteeism surveillance system.

Background: School absenteeism data have been collected daily by the public health unit in Wellington-Dufferin-Guelph, Ontario since 2008. To date, a threshold-based approach has been implemented to raise alerts for community-wide and within-school illness outbreaks. We investigate several statistical modelling approaches to using school absenteeism for influenza surveillance at the regional level, and compare their performances using two metrics.

Pork implicated in a Shiga toxin-producing Escherichia coli O157:H7 outbreak in Ontario, Canada.

Objectives: 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.

Methods: The outbreak investigation included interviews with food handlers and other key associated persons, inspection of food preparation premises, traceback investigations, case finding, analysis of data from an outbreak questionnaire, and laboratory analysis of samples collected from various sources associated with the outbreak.

Occurrence of Anoplocephala perfoliata infection in horses in Ontario, Canada and associations with colic and management practices.

Infection with the tapeworm Anoplocephala perfoliata has been found to be associated with equine colic in horses in the United Kingdom. Using a matched case-control study design, data collected from 117 pairs of horses in Ontario were examined for evidence of associations between risk of colic and A. perfoliata infection, and between seropositivity to infection and management practices.

Calf-level risk factors for neonatal diarrhea and shedding of Cryptosporidium parvum in Ontario dairy calves.

This work was conducted to investigate calf-level factors that influence the risk of neonatal diarrhea and shedding of Cryptosporidium parvum oocysts in calves, on dairy farms in Ontario with histories of calf diarrhea or cryptosporidiosis. Fecal samples were collected weekly for 4 weeks from each of 1045 calves under 30 days of age on 11 dairy farms in south-western Ontario during the summer of 2003 and the winter of 2004. A questionnaire designed to gather information on calf-level management factors was administered on farm for each calf in the study.

Association between management practices and within-herd prevalence of Cryptosporidium parvum shedding on dairy farms in southern Ontario.

To identify management practices associated with an increased within-herd prevalence of Cryptosporidium parvum shedding on dairy farms in southern Ontario, fecal samples were taken from 1089 calves aged 7-28 days, from 119 herds. Information on management practices was obtained by administering a questionnaire compiled using a modified Delphi technique. Data were analyzed using univariable and multivariable negative binomial regression.

Clostridium difficile PCR ribotypes in calves, Canada.

We investigated Clostridium difficile in calves and the similarity between bovine and human C. difficile PCR ribotypes by conducting a case-control study of calves from 102 dairy farms in Canada. Fecal samples from 144 calves with diarrhea and 134 control calves were cultured for C.

Multiattribute evaluation of two simple tests for the detection of Cryptosporidium parvum in calf faeces.

There is a need for simple and inexpensive diagnostic and screening tests for the detection of Cryptosporidium parvum infection in calves. A sucrose wet mount test and a lateral immunochromatography test were evaluated for epidemiological sensitivity and specificity, cost per test, simplicity, test time and ease of batching. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the Cryptosporidium oocyst wall protein (COWP) gene locus, with gel electrophoresis, was used as a gold standard.

Prevalence of Cryptosporidium parvum infection in southwestern Ontario and its association with diarrhea in neonatal dairy calves.

Cryptosporidium parvum infection was detected in 203 (40.6%) of 500 Ontario dairy calves aged 7 to 21 d, on a convenience sample of 51 farms with a history of calf diarrhea. Within-farm prevalence ranged from 0% to 70%, and both shedding and intensity of shedding were significantly associated with diarrhea.