Salmonella Vitkin Outbreak Associated with Bearded Dragons, Canada and United States, 2020-2022.

We identified 2 cases of Salmonella enterica serovar Vitkin infection linked by whole-genome sequencing in infants in Ontario, Canada, during 2022. Both households of the infants reported having bearded dragons as pets. The outbreak strain was also isolated from an environmental sample collected from a patient's bearded dragon enclosure. Twelve cases were detected in the United States, and onset dates occurred during March 2021-September 2022 (isolates related to isolates from Canada within 0-9 allele differences by core-genome multilocus sequence typing). Most US patients (66.7%) were <1 year of age, and most (72.7%) had reported bearded dragon exposure. Hospitalization was reported for 5 (38.5%) of 13 patients. Traceback of bearded dragons identified at least 1 potential common supplier in Southeast Asia. Sharing rare serovar information and whole-genome sequencing data between Canada and the United States can assist in timely identification of outbreaks, including those that might not be detected through routine surveillance.

Two Listeria monocytogenes outbreaks in a cancer centre: onsite food premises and their potential health risk to patients.

BACKGROUND: This report describes two L. monocytogenes outbreak investigations that occurred in March and September of 2018 and that linked illness to a food premises located in an Ontario cancer centre. The cancer centre serves patients from across the province. METHODS: In Ontario, local public health agencies follow up with all reported laboratory-confirmed cases of listeriosis to identify possible sources of disease acquisition and to carry out investigations, including at suspected food premises. The Canadian Food Inspection Agency (CFIA) is notified of any Listeria-positive food product collected in relation to a case. The CFIA traces Listeria-positive product through the food distribution system to identify the contamination source and ensure the implicated manufacturing facility implements corrective measures. RESULTS: Outbreaks one and two each involved three outbreak-confirmed listeriosis cases. All six cases were considered genetically related by whole genome sequencing (WGS). In both outbreaks, outbreak-confirmed cases reported consuming meals at a food premises located in a cancer centre (food premises A) before illness onset. Various open deli meat samples and, in outbreak two, environmental swabs (primarily from the meat slicer) collected from food premises A were genetically related to the outbreak-confirmed cases. Food premises A closed as a result of the investigations. CONCLUSIONS: When procuring on-site food premises, healthcare facilities and institutions serving individuals with immuno-compromising conditions should consider the potential health risk of foods available to their patient population.

Integrating consumer risk perception and awareness with simulation-based quantitative microbial risk assessment using a coupled systems framework: A case study of private groundwater users in Ontario.

Private well users in Ontario are responsible for ensuring the potability of their own private drinking water source through protective actions (i.e., water treatment, well maintenance, and regular water quality testing). In the absence of regulation and limited surveillance, quantitative microbial risk assessment (QMRA) represents the most practical and robust approach to estimating the human health burden attributable to private wells. For an increasingly accurate estimation, QMRA of private well water should be represented by a coupled model, which includes both the socio-cognitive and physical aspects of private well water contamination and microbial exposure. The objective of the current study was to determine levels of waterborne exposure via well water consumption among three sub-groups (i.e., clusters) of private well users in Ontario and quantify the risk of waterborne acute gastrointestinal illness (AGI) attributed to Giardia, shiga-toxin producing E. coli (STEC) and norovirus from private drinking water sources in Ontario. Baseline simulations were utilized to explore the effect of varying socio-cognitive scenarios on model inputs (i.e., increased awareness, protective actions, aging population). The current study uses a large spatio-temporal groundwater quality dataset and cross-sectional province-wide survey to create socio-cognitive-specific QMRA simulations to estimate the risk of waterborne AGI attributed to three enteric pathogens in private drinking waters source in Ontario. Findings suggest significant differences in the level of exposure among sub-groups of private well users. Private well users within Cluster 3 are characterised by higher levels of exposure and annual illness attributable to STEC, Giardia and norovirus than Clusters 1 and 2. Provincial incidence rates of 520.9 (1522 illness per year), 532.1 (2211 illness per year) and 605.5 (5345 illness per year) cases/100,000 private well users per year were predicted for private well users associated with Clusters 1 through 3. Established models will enable development of necessary tools tailored to specific groups of at-risk well users, allowing for preventative public health management of private groundwater sources.

Monkeypox Virus Detection in Different Clinical Specimen Types.

A global monkeypox outbreak began in May 2022. Limited data exist on specimen type performance in associated molecular diagnostics. Consequently, a diverse range of specimen sources were collected in the initial weeks of the outbreak in Ontario, Canada. Our clinical evaluation identified skin lesions as the optimal diagnostic specimen source.

Sources of microbial contamination in the watershed and coastal zone of Soufriere, St. Lucia.

The Sustainable Development Goal 6 calls for global progress by 2030 in treating domestic wastewater and providing access to adequate sanitation facilities. However, meeting these goals will be a challenge for most Small Island Developing States, including Caribbean island nations. In the nearshore zone of the Soufriere region on the Caribbean island of St. Lucia, there is a history of high levels of bacteria of fecal origin. Possible land-based sources of microbial contamination in the Soufriere Bay include discharges from the Soufriere River and transport of wastewater, including fecal material from the town of Soufriere. This area is an important tourist destination and supports a local fishery. To identify the sources of microbial contamination in Soufriere Bay, a range of monitoring methods were employed in this study. In grab samples of surface water collected from the Soufriere River, counts of total coliforms and Escherichia coli were elevated above water quality guidelines. However, the spikes in concentrations of these indicator organisms in the river did not necessarily coincide with the spikes in the levels of total coliforms and E. coli detected in samples collected on the same dates in Soufriere Bay, indicating that there are other sources of pollution in the Bay besides discharges from the river. Monitoring for chemical indicators of wastewater (i.e., caffeine, sucralose, fluconazole) in the Soufriere River indicated that there are inputs of sewage or human fecal material throughout the watershed. However, analysis of Bacteroidales 16S rRNA genetic markers for fecal bacteria originating from humans, bovine ruminants, or other warm-blooded animals indicated that the majority of microbial contamination in the river was not from humans. Monitoring for chemical indicators of wastewater using passive samplers deployed in Soufriere Bay indicated that there are two "hot spots" of contamination located offshore of economically depressed areas of the town of Soufriere. This study indicates that efforts to control contamination of Soufriere Bay by fecal microorganisms must include management of pollution originating from both sewage and domestic animals in the watershed.

Drinking Water Consumption Patterns among Private Well Users in Ontario: Implications for Exposure Assessment of Waterborne Infection.

Understanding the water consumption patterns within a specific population informs development of increasingly accurate, spatially specific exposure and/or risk assessment of waterborne infection. The current study examined the consumption patterns of private well users in Ontario while considering potentially influential underlying sociodemographics, household characteristics, and experiential factors. A province-wide online survey was circulated between May and August 2018 (n = 1,162). Overall, 81.5% of respondents reported daily well water consumption (i.e., tap water). Results indicate a mean daily well water consumption rate of 1,132 mL/day (SD = 649 mL/day) among well water consumers. Gender was significantly associated with well water consumption, with higher consumption rates found among female respondents. The experience of acute gastrointestinal illness (AGI) symptoms or diagnosis in the past 12 months did not impact the volume of water consumed, suggesting that experiencing previous AGI does not decrease consumption volumes, and therefore exposure over time. Significantly higher rates of well water consumption were found among respondents who reported previous testing or ongoing water treatment. Approximately 45.5% of survey respondents who stated that they do not consume well water selected bottled water as their primary household drinking water supply. Bottled water consumption was also not associated with previous AGI experiences. Findings will inform future quantitative microbial risk assessments associated with private well water use by providing spatially and demographically specific estimates of well water consumption.

Comparative genomics of multidrug-resistant Enterococcus spp. isolated from wastewater treatment plants.

BACKGROUND: Wastewater treatment plants (WWTPs) are considered hotspots for the environmental dissemination of antimicrobial resistance (AMR) determinants. Vancomycin-Resistant Enterococcus (VRE) are candidates for gauging the degree of AMR bacteria in wastewater. Enterococcus faecalis and Enterococcus faecium are recognized indicators of fecal contamination in water. Comparative genomics of enterococci isolated from conventional activated sludge (CAS) and biological aerated filter (BAF) WWTPs was conducted. RESULTS: VRE isolates, including E. faecalis (n = 24), E. faecium (n = 11), E. casseliflavus (n = 2) and E. gallinarum (n = 2) were selected for sequencing based on WWTP source, species and AMR phenotype. The pangenomes of E. faecium and E. faecalis were both open. The genomic fraction related to the mobilome was positively correlated with genome size in E. faecium (p < 0.001) and E. faecalis (p < 0.001) and with the number of AMR genes in E. faecium (p = 0.005). Genes conferring vancomycin resistance, including vanA and vanM (E. faecium), vanG (E. faecalis), and vanC (E. casseliflavus/E. gallinarum), were detected in 20 genomes. The most prominent functional AMR genes were efflux pumps and transporters. A minimum of 16, 6, 5 and 3 virulence genes were detected in E. faecium, E. faecalis, E. casseliflavus and E. gallinarum, respectively. Virulence genes were more common in E. faecalis and E. faecium, than E. casseliflavus and E. gallinarum. A number of mobile genetic elements were shared among species. Functional CRISPR/Cas arrays were detected in 13 E. faecalis genomes, with all but one also containing a prophage. The lack of a functional CRISPR/Cas arrays was associated with multi-drug resistance in E. faecium. Phylogenetic analysis demonstrated differential clustering of isolates based on original source but not WWTP. Genes related to phage and CRISPR/Cas arrays could potentially serve as environmental biomarkers. CONCLUSIONS: There was no discernible difference between enterococcal genomes from the CAS and BAF WWTPs. E. faecalis and E. faecium have smaller genomes and harbor more virulence, AMR, and mobile genetic elements than other Enterococcus spp.

Listeria monocytogenes Associated with Pasteurized Chocolate Milk, Ontario, Canada.

In an investigation of a listeriosis outbreak in Ontario, Canada, during November 2015-June 2016, pasteurized chocolate milk was identified as the source. Because listeriosis outbreaks associated with pasteurized milk are rare in North America, these findings highlight that dairy products can be contaminated after pasteurization.

Critical elements for local Indigenous water security in Canada: a narrative review.

Indigenous communities in Canada are over-represented with respect to poor water quality and water advisories. To date, approaches to solve this water crisis have been founded in the Western Science (WS) context with little to no consultation or dialogue with those communities most impacted, and without regard for culture. A literature review was undertaken to: (i) document Indigenous Knowledge (IK), and perspectives regarding water and (ii) to identify current local water security tools utilized by Indigenous communities. The aim is to provide sound evidence regarding the value of ownership and leadership by Indigenous communities in the context of current and appropriate resources available to (re)claim these roles. Solutions must remain consistent with, and founded upon, traditional Indigenous worldviews and cultural values to ensure sustainable water security. Literature reviewed from the past ten years revealed one overarching creation theme with three water-specific themes in Indigenous communities; namely, water from natural sources, water as a life-giving entity, and water and gender. Ultimately, there needs to be a new framing of local water security with the development of tools which engage IK and WS in order to assess local water security and appropriately inform interventions, policies, regulations and legislation.

Microbial source tracking of private well water samples across at-risk regions in southern Ontario and analysis of traditional fecal indicator bacteria assays including culture and qPCR.

Many people living in rural areas rely on privately owned wells as their primary source of drinking water. These water sources are at risk for fecal contamination of human, wildlife, and livestock origin. While traditional bacteriological testing involves culture-based methods, microbial source tracking (MST) assays present an opportunity to additionally determine the source of fecal contamination. This study investigated the main host sources of contamination in private well water samples with high levels of Escherichia coli (E. coli), using MST with human and multi-species specific markers. Fecal contamination of human origin was detected in approximately 50% of samples, indicating that current contamination prevention strategies require reconsideration. The relationship between cattle density and fecal contamination of bovine origin was investigated using a Bovine Bacteroidales specific MST assay. Regional variations of microbial sources were examined, and may inform local primary prevention strategies. Additionally, in order to assess MST and E. coli quantitative real time polymerase chain reaction (qPCR) assays as indicators of fecal contamination, these were compared to E. coli culture methods. Variation in results was observed across all assay methods investigated, suggesting the most appropriate routine bacteriological testing methodology cannot be determined without comparison to a method that directly detects the presence of fecal contamination.

An evaluation of southeastern Ontario recreational water quality.

Fecal contamination in recreational waters causes adverse health outcomes in humans; yet, surprisingly, a paucity of literature addresses recreational water quality in North America. The authors addressed this gap by evaluating E. coli contamination of southeastern Ontario, Canada, recreational beach waters between the years 2008-2011. They tested water samples for microbial contamination by the membrane filtration method. They used Friedman's and repeated measures analyses of variance and descriptive statistics to assess annual and monthly E. coli levels as well as noncompliance to the Ontario bathing beach standard. Seven waters showed high noncompliance to the Ontario standard, which could negatively affect the health of local recreational beach users. The authors' study provides much needed baseline information on beach water quality. They call for greater recreational water sampling and reporting standardization across North American jurisdictions.

Public health response to a large-scale endoscopy infection control lapse in a nonhospital clinic.

OBJECTIVE: To determine whether transmission of blood-borne pathogens (BBPs) (hepatitis B virus [HBV], hepatitis C virus [HCV] and HIV) occurred as a result of endoscopy reprocessing failures identified during an inspection of a nonhospital endoscopy clinic in 2011. METHODS: The present analysis was a retrospective cohort study. Registered notification letters were mailed to 6992 patients who underwent endoscopy from 2002 to 2011 at one Canadian nonhospital endoscopy clinic, informing them of the infection control lapse and offering BBP testing. Multimedia communications and a telephone line supplemented notification. A retrospective study of patients with BBPs was performed with viral genetic testing and risk factor assessment for eligible patients. Risk for infection among patients whose procedure was within seven days of a known positive patient was compared with those whose procedure was performed more than seven days after a known postive patient. The seven-day period was selected as the period most likely to present a risk for transmission based on the documented cleaning procedures at the clinic and the available literature on virus survival. RESULTS: Ninety-five percent (6628 of 6992) of patients/estates were contacted and 5042 of 6728 (75%) living patients completed BBP testing. Three were newly diagnosed with HBV and 14 with HCV. Twenty-three and 48 tested positive for previously known HBV or HCV, respectively, 367 were immune to HBV due to natural infection and one was immune to HBV due to immunization. None tested positive for HIV. Sequencing did not reveal any relationships among the 46 unique case patients with viral genetic test results available. Ninety-three percent of patients reported alternative risk factors for BBP. An increased risk for infection among those who underwent a procedure within seven days of a known HBV or HCV case was not demonstrated. CONCLUSIONS: Endoscopy reprocessing failures were not associated with an increased risk for BBP among individuals tested.

OBJECTIF: Lors de l'inspection d'une clinique d'endoscopie non hospitalière en 2011, déterminer si des pathogènes à diffusion hématogène (PDH; virus de l'hépatite B [VHB], virus de l'hépatite C [VHC] et VIH) sont transmis à cause de la défaillance du retraitement de l'endoscopie. MÉTHODOLOGIE: Dans la présente étude de cohorte rétrospective, les chercheurs ont posté une lettre recommandée à 6 992 patients qui avaient subi une endoscopie entre 2002 et 2011 dans une clinique canadienne d'endoscopie non hospitalière pour les informer d'une défaillance du contrôle des infections et leur offrir un test de dépistage des PDH. Les communications multimédias et les appels téléphoniques ont complété cet avis. Les chercheurs ont effectué une étude rétrospective des patients ayant des PDH au moyen de tests génétiques viraux et d'une évaluation des facteurs de risque des patients admissibles. Ils ont comparé le risque d'infection entre les patients dont l'intervention avait eu lieu dans les sept jours suivant celle d'un patient positif connu ceux dont l'intervalle dépassait sept jours. Cette période de sept jours était la plus susceptible de constituer un risque de transmission compte tenu des mesures de nettoyage attestées à la clinique et les publications sur la survie des virus. RÉSULTATS: Les chercheurs ont pris contact avec 95 % (6 628 cas sur 6 692) des patients et des successions, et 5 042 des 6 728 (75 %) patients vivants ont effectué le test de dépistage des PDH. Trois ont obtenu un nouveau diagnostic de VHB et 14, de VHC. De plus, 23 et 48 ont obtenu des résultats positifs à un VHB ou à un VHC déjà connu, respectivement, 367 étaient immuns au VHB en raison d'une infection naturelle et un, grâce à la vaccination. Aucun n'a obtenu de résultat positif au VIH. Le séquençage a révélé l'absence de lien entre les 46 cas uniques de patients pour qui les résultats du test génétique étaient disponibles. Aussi, 93 % des patients ont signalé d'autres facteurs de risques de PDH. Par ailleurs, on n'a pu démontrer d'augmentation du risque d'infection chez les personnes qui avaient subi une intervention dans les sept jours suivant un cas connu de VHB ou de VHC. CONCLUSIONS: L'échec de retraitement de l'endoscopie ne s'associait pas à une augmentation du risque de PDH chez les personnes qui subissaient un test de dépistage.

Microbial source tracking and spatial analysis of E. coli contaminated private well waters in southeastern Ontario.

Private water supplies, which are the primary source of drinking water for rural communities in developed countries, are at risk of becoming fecally contaminated. It is important to identify the source of contamination in order to better understand and address this human health risk. Microbial source tracking methods using human, bovine and general Bacteroidales markers were performed on 716 well water samples from southeastern Ontario, which had previously tested positive for Escherichia coli. The results were then geospatially analyzed in order to elucidate contamination patterns. Markers for human feces were found in nearly half (49%) of all samples tested, and a statistically significant spatial cluster was observed. A quarter of the samples tested positive for only general Bacteroidales markers (25.7%) and relatively few bovine specific marker positives (12.6%) were found. These findings are fundamental to the understanding of pathogen dynamics and risk in the context of drinking well water and will inform future research regarding host-specific pathogens in private well water samples.

Triage and protocol recommendations for the parasitology laboratory based on an epidemiological investigation of parasite diagnostics in Ontario laboratories.

OBJECTIVES: A study was performed using a subset of Ontario laboratory parasitology data, with three objectives: to describe parasitic infections in Ontario; to identify risk factors for acquiring a parasitic infection using routinely collected information; and to use this information to assess current protocols for parasite testing in laboratories and, in turn, to propose alternatives to optimize the allocation of laboratory resources. METHODS: All parasitology records from January 4, 2010 to September 14, 2010 were reviewed descriptively and risk factor analyses were performed using information collected from requisitions. These results were used to develop preliminary alternative protocols, which considered high-throughput screening tests and inclusion/exclusion criteria for ova and parasite testing; these were then retrospectively analyzed with the dataset to determine appropriateness. RESULTS: Of the 29,260 records analyzed, 10% were multiple samples from single patients submitted on the same day, of which 98% had the same result. Three percent of all parasite tests were positive, with the most prevalent parasites being (in ascending order) Dientamoeba fragilis, Giardia lamblia, Cryptosporidium species and Entamoeba histolytica/dispar. Age and sex were found to be weak risk factors, while rural living was found to be a moderate risk factor for D fragilis, G lamblia and Cryptosporidium infections. The strongest risk factor was travel history, especially for nonendemic parasites. The retrospective analysis of six alternative protocols identified four that may be more efficient than current procedures. CONCLUSIONS: The present study demonstrated that current protocols may be redundant and can be optimized to target prevalent parasites and populations with high risk factors.

OBJECTIFS: Une étude a été menée d'après un sous-groupe de données des laboratoires de parasitologie de l'Ontario pour réaliser trois objectifs : décrire les infections parasitaires en Ontario, déterminer les facteurs de risque d'infection parasitaire d'après la collecte systématique d'information et utiliser l'information pour évaluer les protocoles actuels respectés dans les tests parasitaires en laboratoire, puis proposer des solutions pour optimiser l'affectation des ressources de laboratoire. MÉTHODOLOGIE: Les chercheurs ont effectué une recherche descriptive de tous les dossiers de parasitologie entre le 4 janvier et le 14 septembre 2010, ainsi que des analyses des facteurs de risque à l'aide de l'information figurant dans les réquisitions. Ils ont utilisé les résultats pour préparer de nouveaux protocoles préliminaires, qui tenaient compte des tests de dépistage à haut débit et des critères d'inclusion et d'exclusion des tests d'œufs et de parasites. Ils ont ensuite fait l'analyse rétrospective de l'ensemble des données pour en déterminer la pertinence. RÉSULTATS: Sur les 29 260 dossiers analysés, 10 % provenaient d'échantillons multiples du même patient soumis le même jour, dont 98 % donnaient les mêmes résultats. Par ailleurs, 3 % de tous les tests parasitaires étaient positifs, les parasites les plus prévalents étant (par ordre ascendant) le Dientamoeba fragilis, le Giardia lamblia, les espèces de Cryptosporidium et l'Entamoeba histolytica/dispar. L'âge et le sexe étaient des facteurs de risque faibles, tandis que la vie en milieu rural était un facteur de risque modéré d'infections à D fragilis, à G lamblia et à Cryptosporidium. Les antécédents de voyage étaient les principaux facteurs de risque, particulièrement pour les parasites non endémiques. L'analyse rétrospective des six nouveaux protocoles a établi que quatre d'entre eux seraient plus efficaces que les protocoles actuels. CONCLUSIONS: La présente étude a démontré que les protocoles actuels seraient redondants et pourraient être optimisés pour cibler les parasites prévalents et les populations présentant des facteurs de risque élevés.

An outbreak of Salmonella Infantis linked to shredded pork products from an unlicensed source in multiple health districts, Ontario, Canada, 2021.

Background: An outbreak of Salmonella Infantis was associated with the consumption of shredded pork products at multiple restaurants in Ontario between July 2021 and October 2021. The outbreak involved 36 case-patients from six public health units. The implicated shredded pork products were obtained from an unlicensed source. This is the largest reported outbreak of Salmonella Infantis linked to restaurant food exposures in Ontario, with complexities related to the investigation of unlicensed foods. This article aims to describe the epidemiological, food safety and laboratory investigations that led to the identification and removal of the source of the outbreak from implicated restaurants, including the challenges encountered while investigating an outbreak related to an unlicensed source of food. Methods: Epidemiological and laboratory analyses were conducted to identify the source of the outbreak. Food safety investigations were conducted to ascertain the origin and distribution of the implicated food. Results: Whole-genome sequencing identified the outbreak strain from the isolates of 36 case-patients across six public health units in Ontario. Seven case-patients (19%) were hospitalized. No deaths were reported. The outbreak was linked to shredded pork products (i.e., rinds or skins) that were distributed by an unlicensed meat processor and consumed at various restaurants that served Southeast Asian fusion cuisine concentrated in the Greater Toronto Area. The product was removed from implicated restaurants. Conclusion: Historically, foods from unlicensed sources have been implicated in multiple large outbreaks and continue to be of significant public health risk. The outbreak investigation emphasized the threat of food from unlicensed sources to the public's health and the importance of additional public health interventions to prevent outbreaks linked to unlicensed sources.

Development of a "big data" groundwater microbial contamination index and spatial comparisons with enteric infection rates in southern Ontario.

Big data have become increasingly important for policymakers and scientists but have yet to be employed for the development of spatially specific groundwater contamination indices or protecting human and environmental health. The current study sought to develop a series of indices via analyses of three variables: Non-E. coli coliform (NEC) concentration, E. coli concentration, and the calculated NEC:E. coli concentration ratio. A large microbial water quality dataset comprising 1,104,094 samples collected from 292,638 Ontarian wells between 2010 and 2021 was used. Getis-Ord Gi* (Gi*), Local Moran's I (LMI), and space-time scanning were employed for index development based on identified cluster recurrence. Gi* and LMI identify hot and cold spots, i.e., spatially proximal subregions with similarly high or low contamination magnitudes. Indices were statistically compared with mapped well density and age-adjusted enteric infection rates (i.e., campylobacteriosis, cryptosporidiosis, giardiasis, verotoxigenic E. coli (VTEC) enteritis) at a subregional (N = 298) resolution for evaluation and final index selection. Findings suggest that index development via Gi* represented the most efficacious approach. Developed Gi* indices exhibited no correlation with well density, implying that indices are not biased by rural population density. Gi* indices exhibited positive correlations with mapped infection rates, and were particularly associated with higher bacterial (Campylobacter, VTEC) infection rates among younger sub-populations (p < 0.05). Conversely, no association was found between developed indices and giardiasis rates, an infection not typically associated with private groundwater contamination. Findings suggest that a notable proportion of bacterial infections are associated with groundwater and that the developed Gi* index represents an appropriate spatiotemporal reflection of long-term groundwater quality. Bacterial infection correlations with the NEC:E. coli ratio index (p < 0.001) were markedly different compared to correlations with the E. coli index, implying that the ratio may supplement E. coli monitoring as a groundwater assessment metric capable of elucidating contamination mechanisms. This study may serve as a methodological blueprint for the development of big data-based groundwater contamination indices across the globe.

Emergency department surveillance as a proxy for the prediction of circulating respiratory viral disease in Eastern Ontario.

BACKGROUND: Seasonal outbreaks of winter respiratory viruses are responsible for increases in morbidity and mortality in the community. Previous studies have used hospitalizations, intensive care unit and emergency department (ED) visits as indicators of seasonal influenza incidence. OBJECTIVES: To evaluate whether ED visits can be used as a proxy to detect respiratory viral disease outbreaks, as measured by laboratory confirmation. METHODS: An Emergency Department Syndromic Surveillance system was used to collect ED chief complaints in Eastern Ontario from 2006 to 2010. Comparable laboratory-confirmed cases of respiratory viral infections were collected from the Public Health Ontario Laboratory in Kingston, Ontario. Correlations between ED visits and laboratory-confirmed cases were calculated. RESULTS: Laboratory-confirmed cases of selected respiratory viruses were significantly correlated with ED visits for respiratory and fever/influenza-like illness. In particular, respiratory syncytial virus (Spearman's rho = 0.593), rhinovirus (Spearman's rho = 0.280), influenza A (Spearman's rho = 0.528), influenza B (Spearman's rho = 0.426) and pH1N1 (Spearman's rho = 0.470) increased laboratory test levels were correlated with increased volume of ED visits across a number of age demographics. For the entire study population and all studied viruses, the Spearman's rho was 0.702, suggesting a strong correlation with ED visits. Laboratory-confirmed cases lagged in reporting by between one and two weeks for influenza A and pH1N1 compared with ED visit volume. CONCLUSION: These findings support the use of an Emergency Department Syndromic Surveillance system to track the incidence of respiratory viral disease in the community. These methods are efficient and can be performed using automated electronic data entry versus the inherent delays in the primary care sentinel surveillance system, and can aid the timely implementation of preventive and preparatory health interventions.

HISTORIQUE: Les éclosions saisonnières des virus respiratoires hivernaux sont responsables d'augmentations de la morbidité et de la mortalité dans la collectivité. Les études antérieures faisant appel aux hospitalisations, aux séjours aux unités de soins intensifs et aux consultations à l'urgence comme indicateurs de l'incidence d'influenza saisonnière. OBJECTIFS: Évaluer si les consultations à l'urgence pour déceler les éclosions de maladies respiratoires virales peuvent remplacer les confirmations mesurées en laboratoire. MÉTHODOLOGIE: Les chercheurs ont utilisé un système de surveillance syndromique des urgences pour colliger les principaux problèmes ayant suscité une consultation à l'urgence entre 2006 et 2010 dans l'est de l'Ontario. Ils ont colligé des cas comparables d'infections respiratoires virales confirmés en laboratoire auprès des Laboratoires de santé publique de l'Ontario situés à Kingston, en Ontario. Ils ont calculé les corrélations entre les consultations à l'urgence et les cas confirmés en laboratoire. RÉSULTATS: Les cas confirmés en laboratoire de certains virus respiratoires possédaient une corrélation significative avec les consultations à l'urgence en raison de maladies respiratoire, liées à la fièvre ou de type grippal. Notamment, l'augmentation en laboratoire des taux de virus respiratoire syncytial (Rho de Spearman = 0,593), de rhinovirus (Rho de Spearman = 0,280), d'influenza A (Rho de Spearman = 0,528), d'influenza B (Rho de Spearman = 0,426) et de grippe pH1N1 (Rho de Spearman = 0,470) était corrélée avec l'augmentation du volume de consultations à l'urgence dans plusieurs groupes d'âge. Dans l'ensemble de la population et des virus à l'étude, le Rho de Spearman s'établissait à 0,702, ce qui laisse supposer une forte corrélation avec les consultations à l'urgence. Les déclarations de cas d'influenza A et de grippe pH1N1 confirmés en laboratoire avaient de une à deux semaines de retard par rapport au volume de consultations à l'urgence. CONCLUSION: Ces résultats appuient le recours à un système de surveillance syndromique des urgences pour suivre l'incidence de maladies respiratoires virales dans la collectivité. Ces méthodes sont efficaces et peuvent être effectuées au moyen de saisies de données électroniques automatisées plutôt que de s'associer aux délais inhérents au système de surveillance sentinelle en soins de première ligne, et elles peuvent contribuer à la mise en œuvre rapide d'interventions de santé préventives et préparatoires.

Classification of sub-populations for quantitative risk assessment based on awareness and perception: A cross-sectional population study of private well users in Ontario.

Private well users in Ontario are responsible for protective actions, including source maintenance, treatment, and submitting samples for laboratory testing. However, low participation rates are reported, thus constituting a public health concern, as risk mitigation behaviours can directly reduce exposure to waterborne pathogens. The current study examined the combined effects of socio-demographic profile, experience(s), and "risk domains" (i.e., awareness, attitudes, risk perceptions and beliefs) on behaviours, and subsequently classified private well users in Ontario based on cognitive factors. A province-wide online survey (n = 1228) was employed to quantify Ontario well owners' awareness, perceptions, and behaviours in relation to their personal groundwater supply and local contamination sources. A scoring protocol for four risk domains was developed. Two-step cluster analysis was used to classify respondents based on individual risk domain scores. Logistic regression was employed to identify key variables associated with cluster membership (i.e., profile analysis). Overall, 1140 survey respondents were included for analyses. Three distinct clusters were identified based on two risk domains; groundwater awareness and source risk perception. Profile analyses indicate "low awareness and source risk perception" (Low A/SRP) members were more likely male, while "low awareness and moderate source risk perception" (Low A/Mod SRP) members were more likely female and bottled water users. Well users characterised as "high awareness and source risk perception" (High A/SRP) were more likely to report higher educational attainment and previous well water testing. Findings illustrate that socio-cognitive clusters and their components (i.e., demographics, awareness, attitudes, perceptions, experiences, and protective actions) are distinct based on the likelihood, frequency, and magnitude of waterborne pathogen exposures (i.e., risk-based). Risk-based clustering, when incorporated into quantitative microbial risk assessment, enables the development of effective risk management and communication initiatives that are demographically focused and tailored to specific sub-groups.

Assessing the risk of acute gastrointestinal illness attributable to three enteric pathogens from contaminated private water wells in Ontario.

The province of Ontario compromises the largest groundwater reliant population in Canada serving approximately 1.6 million individuals. Unlike municipal water systems, private well water is not required to meet water quality regulatory standards and thus source maintenance, treatment and testing remains the responsibility of the well owner. Infections associated with private drinking water systems are rarely documented given their typically sporadic nature, thus the human health effects (e.g., acute gastrointestinal illness (AGI)) on consumers remains relatively unknown, representing a significant gap in water safety management. The current study sought to quantify the risk of waterborne AGI attributed to Giardia, shiga-toxin producing E. coli (STEC) and norovirus from private drinking water sources in Ontario using Monte Carlo simulation-based quantitative microbial risk assessment (QMRA). Findings suggest that consumption of contaminated private well water in Ontario is responsible for approximately 4823 AGI cases annually, with 3464 (71.8%) and 1359 (28.1%) AGI cases predicted to occur in consolidated and unconsolidated aquifers, respectively. By pathogen, waterborne AGI was attributed to norovirus (62%; 2991/4823), Giardia (24.6%; 1186/4823) and STEC (13.4%; 646/4823). The developed QMRA framework was used to assess the potential health impacts of partial and total well water treatment system failure. In the unlikely event of total treatment failure, total mean annual illnesses are predicted to almost double (4217 to 7064 cases per year), highlighting the importance of effective water treatment and comprehensive testing programs in reducing infectious health risks attributable to private well water in Ontario. Study findings indicate significant underreporting of waterborne AGI rates at the provincial level likely biasing public health interventions and programs that are effective in monitoring and minimizing the health risk associated with private well water.

Community Legionella outbreak linked to a cooling tower, 2022.

Background: Thirty-five laboratory-confirmed legionellosis cases were reported to the Simcoe Muskoka District Health Unit (Ontario, Canada) between September 27, 2022, and October 15, 2022, resulting in one death and 29 hospitalizations. This article describes the Legionella outbreak and highlights activities for managing the outbreak, including various environmental and infrastructural controls associated with the public health response and some of the unique challenges and potential solutions to mitigate future outbreaks. Methods: All cases of legionellosis were reported to and investigated by the local provincial health unit. Within a 6 km radius around the community, 27 cooling towers (CTs) were identified as potential sources of Legionella. Environmental samples were collected from 19 CTs and a long-term care home. Outcome: Of the 35 cases, 29 (83%) were hospitalized (including three long-term care residents) with two requiring intubation/ventilation. Of the five sputa (clinical isolates) collected from confirmed cases, four tested positive for Legionella pneumophila (one was positive for L. pneumophila serogroup 1-with the same sequence type as one of the CT isolates). Education and recommendations were provided by the local provincial health unit to operators to improve CT operation. Conclusion: Detection and management of community legionellosis outbreaks associated with CTs involve resources and time to properly identify and control risks. Measures for community risk mitigation included coordinating with provincial and community partners, developing methods to rapidly identify CTs as a likely source of infection and applying operational/maintenance/testing standards for CTs to control bacterial growth and minimize the dispersion of contaminated aerosols.