The pandemic produced by the COVID-19 virus has resulted in an estimated 6.4 million deaths worldwide and a rise in unemployment rates, notably in the UK. Healthcare monitoring systems encounter several obstacles when regulating and anticipating epidemics. The study aims to present the AF-HIDOP model, an artificial neural network Fast Fourier Transform hybrid technique, for the early identification and prediction of the risk of Covid-19 spreading within a specific time and region. The model consists of the following five stages: 1) Data collection and preprocessing from reliable sources; 2) Optimal machine learning algorithm selection, with the Random Forest tree (RF) classifier achieving 94.4% accuracy; 3) Dimensionality reduction utilising principal components analysis (PCA) to optimise the impact of the data volume; 4) Predicting case numbers utilising an artificial neural network model, with 52% accuracy; 5) Enhancing accuracy by incorporating Fast Fourier Transform (FFT) feature extraction and ANN, resulting in 91% accuracy for multi-level spread risk classification. The AF-HIDOP model provides prediction accuracy ranging from moderate to high, addressing issues in healthcare-based datasets and costs of computing, and may have potential uses in monitoring and managing infectious disease epidemics.

Salmonella é o agente etiológico mais comumente envolvido em casos e surtos de doenças diarréicas de origem alimentar no Brasil e outros países. A preocupação com este patógeno é, ainda, maior quando se verifica o surgimento e disseminação de cepas multi-resistentes e potencialmente mais patogênicas. O presente estudo teve como objetivo caracterizar 237 cepas Salmonella spp. distribuídas entre 50 sorovares diferentes, isoladas de alimentos associados e não associados à toxinfecções alimentares, quanto ao perfil de susceptibilidade antimicrobiana e presença dos genes de virulência spvC, invA, sefA e pefA. O gene invA foi detectado em todas as cepas de Salmonella. Com relação aos demais genes estudados, spvC e pefA foram encontrados em 48,1% e 44,3% das cepas, respectivamente. O gene sefA foi detectado em 31,6% das cepas, estando presente somente entre as cepas de S. Enteritidis. Ainda com relação à presença dos genes de virulência, as cepas de S. Enteritidis foram classificadas em três perfis, com predominância (90,7%) do perfil constituído pelos quatro genes de virulência. Quanto ao perfil de susceptibilidade antimicrobiana, 46,8% do total de cepas avaliadas foram sensíveis a todos os agentes antimicrobianos, 51,9% resistentes à pelo menos uma droga e 1,3% das cepas apresentaram apenas resistência intermediária. Multi-resistência foi observada em 10,5% das cepas. As maiores taxas de resistência foram observadas para estreptomicina (35,9%), ácido nalídixico (16,9%), tetraciclina (5,9%) e gentamicina (4,6%). Não foram detectadas cepas resistentes à cefoxitina, cefalotina, cefotaxima, amicacina, ciprofloxaxina e imipenem. Os resultados do presente estudo mostram a ampla distribuição dos genes de virulência e ocorrência de resistência antimicrobiana tanto nas cepas associadas a surtos como naquelas não envolvidas em toxinfecções alimentares, sendo os produtos de origem avícola fontes importantes de Salmonella com estas características. / Salmonella is the most common causative agent of cases and outbreaks of foodborne diarrhoeal diseases in Brazil and other countries. The concern with this pathogen is even greater considering the emergence and spread of multi-resistant and potentially more pathogenic strains. In this study, the antimicrobial susceptibility profile and the presence of virulence genes spvC, invA, sefA and pefA were examined in 237 Salmonella strains belonging to 50 serovars, isolated from foods associated and nonassociated to foodborne disease outbreaks. The gene invA was detected in all Salmonella strains. The genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The sefA gene was found in 31.6% of strains and detected only in S. Enteritidis strains. According to the presence of virulence genes, S. Enteritidis strains were grouped in into three profiles, being the one consisting of four virulence genes the most common profile (90.7%). Among strains, 46.8% were sensitive to all antibiotics, 51.9% resistant to at least one drug and 1.3% of the strains presented intermediate resistance. Multi-resistance was seen in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%), nalidixic acid (16.9%), tetracycline (5.9%) and gentamicin (4.6%). No resistance was observed to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxaxina and imipenem. The results of this study show the wide distribution of virulence genes and occurrence of antimicrobial resistance in strains both associated and non-associated to foodborne disease outbreaks, being poultry products the major sources of Salmonella with these characteristics.

Salmonella é o agente etiológico mais comumente envolvido em casos e surtos de doenças diarréicas de origem alimentar no Brasil e outros países. A preocupação com este patógeno é, ainda, maior quando se verifica o surgimento e disseminação de cepas multi-resistentes e potencialmente mais patogênicas. O presente estudo teve como objetivo caracterizar 237 cepas Salmonella spp. distribuídas entre 50 sorovares diferentes, isoladas de alimentos associados e não associados à toxinfecções alimentares, quanto ao perfil de susceptibilidade antimicrobiana e presença dos genes de virulência spvC, invA, sefA e pefA. O gene invA foi detectado em todas as cepas de Salmonella. Com relação aos demais genes estudados, spvC e pefA foram encontrados em 48,1% e 44,3% das cepas, respectivamente. O gene sefA foi detectado em 31,6% das cepas, estando presente somente entre as cepas de S. Enteritidis. Ainda com relação à presença dos genes de virulência, as cepas de S. Enteritidis foram classificadas em três perfis, com predominância (90,7%) do perfil constituído pelos quatro genes de virulência. Quanto ao perfil de susceptibilidade antimicrobiana, 46,8% do total de cepas avaliadas foram sensíveis a todos os agentes antimicrobianos, 51,9% resistentes à pelo menos uma droga e 1,3% das cepas apresentaram apenas resistência intermediária. Multi-resistência foi observada em 10,5% das cepas. As maiores taxas de resistência foram observadas para estreptomicina (35,9%), ácido nalídixico (16,9%), tetraciclina (5,9%) e gentamicina (4,6%). Não foram detectadas cepas resistentes à cefoxitina, cefalotina, cefotaxima, amicacina, ciprofloxaxina e imipenem. Os resultados do presente estudo mostram a ampla distribuição dos genes de virulência e ocorrência de resistência antimicrobiana tanto nas cepas associadas a surtos como naquelas não envolvidas em toxinfecções alimentares, sendo os produtos de origem avícola fontes importantes de Salmonella com estas características. / Salmonella is the most common causative agent of cases and outbreaks of foodborne diarrhoeal diseases in Brazil and other countries. The concern with this pathogen is even greater considering the emergence and spread of multi-resistant and potentially more pathogenic strains. In this study, the antimicrobial susceptibility profile and the presence of virulence genes spvC, invA, sefA and pefA were examined in 237 Salmonella strains belonging to 50 serovars, isolated from foods associated and nonassociated to foodborne disease outbreaks. The gene invA was detected in all Salmonella strains. The genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The sefA gene was found in 31.6% of strains and detected only in S. Enteritidis strains. According to the presence of virulence genes, S. Enteritidis strains were grouped in into three profiles, being the one consisting of four virulence genes the most common profile (90.7%). Among strains, 46.8% were sensitive to all antibiotics, 51.9% resistant to at least one drug and 1.3% of the strains presented intermediate resistance. Multi-resistance was seen in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%), nalidixic acid (16.9%), tetracycline (5.9%) and gentamicin (4.6%). No resistance was observed to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxaxina and imipenem. The results of this study show the wide distribution of virulence genes and occurrence of antimicrobial resistance in strains both associated and non-associated to foodborne disease outbreaks, being poultry products the major sources of Salmonella with these characteristics.

Les épidémies de gastro-entérite aigüe liées à l’eau du robinet demeurent un enjeu de santé publique au 21ème siècle dans les pays développés. La majorité des dispositifs de surveillance mis en place dans les pays se caractérisent par une sous-déclaration. En France, l’amélioration de la surveillance de ces évènements repose sur l’exploitation des données de l’Assurance Maladie. L’objectif de notre travail est de proposer une méthode pour améliorer la sensibilité et la spécificité de la détection des épidémies de gastro-entérite aigüe d’origine hydrique. Trois études ont été menées pour i) évaluer la capacité des données de l’Assurance Maladie à décrire des épidémies de gastro-entérite aigüe d’origine hydrique, ii) adapter une méthode de détection spatio-temporelle en intégrant l’exposition à l’eau du robinet, iii) évaluer les performances de cette méthode. Notre travail a permis de développer une méthode de détection spatio-temporelle des épidémies hydriques en tenant compte des unités géographiques de distribution d’eau avec une bonne sensibilité et une bonne valeur prédictive positive. Les performances de détection sont principalement liées à la taille de l’épidémie. La capacité des données de l’Assurance Maladie à détecter des épidémies d’origine hydrique peut être influencée par les habitudes de recours aux soins, la sensibilisation de la population au risque infectieux d’origine hydrique et le niveau d’agrégation temporel des cas de gastro-entérite aigüe. La finalité de nos travaux de recherche est l’application opérationnelle pour la détection automatisée des épidémies hydriques dans une finalité de prévention et de réduction de leur impact sanitaire. / Waterborne disease outbreaks (WBDO) of acute gastrointestinal illness remain a public health concern in the 21st century in developed countries. Almost all surveillance systems implemented in countries are characterized by underreporting. In France, the improvement of monitoring these events is based on the use of data from the French Health Insurance. The aim of our work was to propose a method to improve the sensitivity and specificity of the detection of WBDO. Three studies were conducted to i) evaluate the ability of French Health Insurance data to describe WBDO ii) apply a method of space-time detection by integrating the exposure to tap water, iii) evaluate the performance of this method. Our work allowed developing a method of space-time detection of WBDO by taking into account geographical units for drinking water networks units with a good sensitivity and positive predictive value. The performances for detection are mainly related to the size of the epidemic. The ability of the data from the French Health Insurance to detect WBDO can be influenced by the health-seeking behavior of people, awareness of the population to the risk of WBDO and the temporal aggregation level of cases of acute gastrointestinal illness. The purpose of our research is to carry out an operational design for the automated detection of WBDO in a purpose of prevention and reduction of health impact.

<p><strong>ABSTRACT</strong><strong></strong></p> <p><strong>Background</strong>: Healthcare-associated infections (HAIs) and HAI disease outbreaks present challenges for healthcare facilities. In 2008, a <em>Clostridium difficile</em> outbreak in Ontario resulted in the deaths of 91 patients and raised awareness of HAIs. Over the last 5 years, the outbreak rate has risen dramatically. Traditionally, HAI research has focused on epidemiology, healthcare systems, and the economic burden. Little is known about the impact HAI disease outbreaks have on the work of healthcare professionals.</p> <p><strong>Purpose</strong>: The purpose of this study was to examine the effects of HAI outbreaks on healthcare professionals in a large acute care hospital in Ontario.</p> <p><strong>Methods</strong>:<strong> </strong>A retrospective exploratory case study approach was used, including individual interviews, document analysis, and incidence analysis of HAIs hospital data. The sample was frontline nurses, clinical managers, infection control professionals, and environmental service staff. Document analysis included hospital policies and protocols related to infectious diseases and HAI disease outbreaks.</p> <p><strong>Findings</strong>: The incidence rates of Methicillin-resistant s<em>taphylococcus aureus</em>, <em>Clostridium difficile</em>, and Vancomycin-resistant<em> </em>enterococci<em> </em>have decreased but remained above the provincial benchmarks. The daily work of healthcare professionals was impacted by HAI outbreaks. Nurses experienced workload challenges, time pressures, and increased documentation. Infection control professionals' responsibilities have expanded. The environmental services staffs' cleaning processes have become more intensive. In response, several unique innovations were developed by hospital staff.</p> <p><strong>Conclusion</strong>: The daily work of healthcare professionals at the study site has been affected by HAI outbreaks. Implications for future research include the need to review healthcare professionals’ workloads and evaluate contributing factors to HAI outbreaks.</p> / Master of Science in Nursing (MSN)

<p dir="ltr">In this dissertation, I explore how human actions (climate change, road salt, land use change, species invasions) interact with and influence morphology, disease, and population dynamics in freshwater organisms (amphibians and aquatic crustaceans). First, I examined how the incidence and timing of disease epidemics in native species (<i>Daphnia dentifera</i>) caused by a generalist parasite (<i>Metschnikowia bicuspidata</i>) influenced the success and impact of an invasive species (<i>Daphnia lumholtzi</i>) in freshwater zooplankton (Chapter 1). In the following chapter, I explored how host-parasite interactions are affected by the interactive effects of multiple environmental stressors, focusing on American bullfrog tadpoles (<i>Lithobates catesbeianus</i>), two of their common parasites (<i>Batrachochytrium dendrobatidis</i> (<i>Bd</i>) and trematode parasites in the family Echinostomatidae), and two common stressors (fluctuating temperatures and sublethal road salt pollution; Chapter 2). Finally, I investigated how the combination of climate (temperature and precipitation) and land use (developed and/or forested area) change have influenced the body size of a common toad (Fowler’s toad, <i>Anaxyrus fowleri</i>) from 1930 – 2020 utilizing museum specimens (Chapter 3). Together, this research establishes how emerging and persistent anthropogenic environmental stressors will interact to affect morphology, disease, and population dynamics in vulnerable freshwater organisms.</p>