Adverse Childhood Experiences (ACEs) including experiences of neglect and abuse have been shown to negatively impact the victims’ health outcomes. While the ACE score methodology has been widely accepted as the method for measuring childhood trauma, the severity of the abuse has not been accounted for through research. The aim of this research was to assess the duration and frequency of childhood emotional and physical abuse in addition to prevalence among college aged adults, to bridge this gap in the literature. A modified ACE and health behavior questionnaire was administered online at one university beginning July through December of 2014. A sample of 965 participants aged ≥ 18 were included in this study. Two ACE questions, “did a parent or other adult in the household often or very often swear at you, insult you, put you down, or humiliate you? Or, act in any way that made you afraid that you might be physically hurt?” and “did a parent or other adult in the household often or very often push, grab, slap, or throw something at you? Or ever hit you so hard that you had marks or were injured?” were asked to measure the prevalence of emotional and physical abuse, respectively. Descriptive statistics were completed in SAS for age, race, gender, emotional abuse and physical abuse. Frequencies, proportions and corresponding p-values were reported. The sample distribution included: female (69%), age average 20 years (M = 20.21, SD = 4.07), and white (84.9%). In total 29.01% of the sample reported exposure to childhood emotional or physical abuse and 37.5% reported both experiences. Females reported a higher proportion of emotional abuse and less proportion of physical abuse (27.59% and 12.29%) compared to males (24.50% and 15.44%). However, gender differences were not significant, X2 = 1.01, p>0.05 and X2 = 1.77, p>0.05. Of those reporting abuse, about two thirds of emotional abuse and one third of physical abuse occurred frequently defined as occurring either ‘daily’, ‘at least once a week’ or ‘at least once a month’. Modal frequency was ‘at least once a week’ for both female (30.74%) and male (20.31%). More than half of the abusive experiences (60.3% emotional and 53.9% physical) happened for more than two years. Experiences of childhood emotional and physical abuse are common among this sample of college age adults and the occurrence of one type of abuse is most often accompanied by the occurrence of another. This result is consistent with national research that has been done on adult populations. In cases where abuse occurred for this sample, the experiences were frequent and for an extended period of time. An understanding of the prevalence of childhood physical and emotional abuse among college aged adults and the discussion of its implications should be included in college health and counseling programs. Knowledge of the frequency and duration of abuse is critical in identifying the high risk population and developing personalized and targeted programs addressing their specific needs.

Introduction: HIV remains a leading cause of death globally, with over two-thirds of the cases in sub-Saharan Africa. Zimbabwe, a country located in East Africa, part of Sub-Saharan Africa, ranks in the top five countries with the highest prevalence of HIV in Africa (HIV prevalence in Zimbabwe estimated as 21.4% in 2019). Previous studies demonstrated HIV testing prevalence of 66.9% in East Africa. This study aimed to assess the prevalence of HIV testing amongst women of reproductive age in Zimbabwe, alongside some predictors of HIV testing amongst this population. Methods: Cross-sectional study design using the 2015 Demographic and Health Surveys (DHS) data for women aged 15-49. The prevalence of HIV testing as the outcome variable and the highest educational level, age at first sex, current marital status, and condom use as the predictor variables of interest were assessed. Descriptive statistics (frequencies, percents) and test of significance (using Chi-squared test)were conducted. Bivariate and multivariate logistic regression were completed to assess for the independent relationship between each predictor variable and HIV testing prevalence and, all predictor variables and HIV testing prevalence, respectively. Odds ratio estimates, 95% confidence intervals and p-values werereported. All analyses were performed using the Statistical Analysis System (SAS) version 9.4. The initial sample size included 9955 women. However, the effective sample size used in the statistical analysis was 7130 after accounting for missing variables. Results: About 9 in 10 women in the sample had ever been tested for HIV. Secondary education was the most prevalent highest level of education (64%). About 67% women had their first sex at age 15-19; peak incidence seen at ages 17 and 18 (15.3%). Multivariate analysis showed statistically significant associations between all independent variables and HIV testing (P-value Conclusion: Increasing highest educational level, age at first sex and condom use in Zimbabwe would likely increase the prevalence of HIV testing further. Focused education on the importance of HIV testing before the age of 15 will be beneficial in ensuring HIV testing as soon as sexual intercourse is established. Policy efforts are needed to address these HIV testing predictors. Causality is not implied.

BACKGROUND: South Africa bares a significant burden of HIV and imaging is commonly performed as part of the workup for respiratory distress. OBJECTIVES: The aim of this study was to document the prevalence of pulmonary thrombo-embolic disease (PTED) and other findings in HIV-infected patients referred for CT pulmonary angiography (CTPA) for suspected PTED. METHOD: Forty CTPA studies of documented HIV-infected individuals investigated for suspected PTED during a 1-year period were retrieved, anonymised and interpreted by three consultant radiologists. Inter-reader reliability was calculated using Free Marginal multi-rater Kappa. RESULTS: Fourteen of the forty cases (35%) were positive for PTED. In the pulmonary embolism (PE)-positive group, 57.14% had peripheral disease and 42.86% had both peripheral and central disease. Associated findings in the PE-positive cases were pulmonary infarcts (17.5%), mosaic attenuation (17.5%) and linear atelectasis (7.5%). The most common incidental findings were solid pulmonary nodules (52.5%), non-wedge-shaped consolidation (45%), cardiomegaly (52.5%) and enlarged intra-thoracic lymph nodes (52.5%). Thirty per cent of the study population had findings related directly to the presence of PTED, whilst most cases in the study (77.5%) had pulmonary findings unrelated to PTED. In the PE-negative cases, 55% reported emergent findings that warranted immediate or urgent medical attention. CONCLUSION: Computed tomography pulmonary angiography imaging is critical for diagnosing PE. However, further investigation into the judicious application of CTPA in HIV-infected patients with suspected PTED is required, as CTPA findings in most of the cases in this study were unrelated to PE.

BACKGROUND: The increasing prevalence of undiagnosed and diagnosed type 2 diabetes (T2D) posed a major challenge for public health and thus screening for T2D becomes essentially important. The social-demographical factors associated with the use of T2D screening have been widely studied, however, little is known about the impact of behavioral factors, mental health and chronic diseases on prevalence of screening, especially by gender and age groups. METHODS: We investigated the impact of behavioral factors, mental health and chronic diseases across gender and age groups on the usage rate of T2D screening. To analyze the likelihood of the use of T2D screening, we performed weighted binomial logistic regression analyses. RESULTS: Obesity, physical activity and smoking increased the use of T2D screening for females more than for males, and alcohol use increased screenings only for females. Serious psychological distress (SPD) was found to have a positive association with the use of T2D screening for females rather than for males; whereas hypertension and diabetes increased the use of T2D screening for males more than for females. Physical activity was an effective predictor of screening for T2D in the groups of 45-64 years and 65 years or older. Former drinking was positively associated with T2D screening for people aged 65 or older, and smoking was found to increase the odds of screening for T2D for people aged less than 65. CONCLUSIONS: Behavioral factors, mental health, and chronic diseases were significantly associated with the use of T2D screening and further demonstrated that gender differences exist in the role of above factors.

INTRODUCTION: Several studies identified a link between gastroesophageal reflux disease (GERD) and obstructive sleep apnea (OSA). GERD is a condition in which acid reflux from the stomach to the esophagus causes troublesome symptoms. On the other hand, OSA is defined as a sleep-related breathing disorder in which airflow significantly decreases or ceases due to upper airway obstruction, leading to arousal from sleep. OSA was found to be associated with GERD. In this study, we aim to study the characteristics and concurrent risk factors associated with GERD and OSA in a large population-based study. METHODS: Patients with the diagnosis of GERD were extracted from the National Inpatient Database (NIS) for the years 2016 to 2019. Patients' age, gender, race, and hospital information, including region and bed size, were extracted and considered as baseline characteristics. The comorbidities included are hypertension (HTN), atrial fibrillation (AFib), congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), pulmonary hypertension (PHTN), obesity, and smoking. Patients younger than 18 years old were excluded from this study. Results: Out of 22,677,620 patients with the diagnosis of GERD, 12.21% had a concurrent diagnosis of OSA (compared to 4.79% in patients without GERD, p-value <0.001). The mean age of patients with GERD and OSA was 64.47 years vs 65.42 years in patients without OSA (p-value <0.001). The GERD and OSA group had almost identical gender distribution compared to the GERD only group, as it was predominantly female patients. The white and black races were slightly more prevalent in the GERD and OSA group compared to the GERD only group. Regarding comorbidities, the prevalence of obesity was more clear in the GERD and OSA group. It was noted that the group of patients who carry a diagnosis of GERD and OSA have more prevalence of diabetes (DM), hypertension (HTN), obesity, atrial fibrillation (Afib), congestive heart failure (CHF), and pulmonary hypertension (PHTN). Patients with GERD and OSA were 21% less likely to be older than 65 years rather than younger (95% CI: 0.79-0.8, p-value <0.001), 35% less likely to be females (95% CI: 0.65-0.65, p-value <0.001), and 22% less likely to be non-white (95% CI: 0.77-0.8, p-value <0.001). Obesity was found to be the strongest association with this population, followed by PHTN, CHF, DM, HTN, Afib, and lastly smoking. CONCLUSION: Patients with GERD and OSA were found more likely to be female, white, living in the southern part of the United States, obese, diabetes mellitus type 2, and being active smokers.

Aims: The objective was to investigate if gender differences exist in the associations between periodontitis and type 2 diabetes. Disproportionate disparities by gender were found to exist in rates of both periodontitis and diabetes with respect to demographics and behavioural predictors that cannot be explained solely by the well-established association between these two diseases. Materials and methods: Multiple datasets were extracted from the National Health and Nutrition Examination Survey (NHANES) 2009–2014, which used a stratified multistage probability sampling to obtain samples from all civilian non-institutionalised people in the USA. Bivariate relationships between each explanatory variable and periodontitis level were assessed with odds ratios (OR) and their 95% confidence intervals (CI). A set of weighted logistic regression models was used to investigate the association differentiations between periodontitis and diabetes by gender. C-statistics measured the goodness-of-fit of weighted logistic regression models. Results: The prevalence of moderate–severe periodontitis was 36.39% and 22.71% among participants with type 2 diabetes and without diabetes, respectively. Type 2 diabetes was significantly associated with moderate–severe periodontitis OR (OR = 1.47, 95% CI: 1.18–1.82) among males even after adjusting for demographics, socioeconomic status and oral health behaviours. The aforementioned relationship was not found in females. Furthermore, different relationships of moderate–severe periodontitis with body mass index and the use of mouthwash were found between the males and females. Conclusions: The current findings suggest that important improvements in the development of gender-specific strategies in prevention, such as oral home-care, to reduce the high prevalence of periodontal disease and maintain good oral health are vital, and are especially important for male diabetic patients and those who are at high risk of developing diabetes, such as those who are obese.

The rapid spread of antibiotic resistance is a major global health concern, jeopardizing the successful treatment of bacterial infections. Natural environments are potential hotspots for the emergence and spread of antibiotic resistance genes (ARGs). Among these potential hotspots, aquatic ecosystems are of particular concern, as they receive wastewater containing antibiotic-resistant bacteria and ARGs originating from both human and animal sources. Several key questions remain to be addressed. What is the fate of ARGs in receiving water bodies? What are implications of environmental ARGs for human health? How does wastewater discharge impacts aquatic microbial communities with regard to the overall ecosystem well-being? The objective of this work was to investigate the impact of wastewater, seasonal variations, and the riverine compartment on the prevalence of selected ARGs and the composition of natural microbial communities in a near-pristine river, and to specifically assess the effect of antibiotics on riverine microbial communities. Quantitative real-time PCR was used to monitor the abundance of three indicator ARGs (sul1 and sul2, conferring resistance against sulfonamide antibiotics, and intI1, a marker for anthropogenic pollution) upstream and downstream from a wastewater treatment plant (WWTP). Furthermore, the impact of WWTP effluent on the riverine microbial community was examined through 16S rRNA amplicon sequencing. Wastewater was the main source of all three target genes and significantly altered the microbial community in the river. The surface water compartment served as a dissemination route for ARGs, with increased prevalence even 13 km downstream of the WWTP, particularly during the summer season when the proportion of wastewater in the river was high. Notably, riverbed biofilms served as a local reservoir for ARGs only at the discharge point, with little abundance of target genes further downstream. The sulfonamide antibiotic sulfamethoxazole (SMX) was persistent in both near-pristine and wastewater-impacted river water when introduced at a concentration of 12.5 µg/L, but had neglectable effects on the microbial community diversity. Interestingly, concentrations as high as 100 µg/L SMX induced a short-term increase in microbial activity in both surface water and biofilm compartment, as revealed by bulk and nanoscale measurements. Altogether, this work underscores the fundamental role of wastewater treatment in combating the environmental dissemination of antibiotic resistance.:Summary 1 Zusammenfassung 5 1 Introduction 9 1.1 Rundown of the global antibiotic resistance crisis 9 1.1.1 History of antibiotics 9 1.1.2 Emergence of antibiotic resistance 9 1.1.3 Integrons as vehicles for antibiotic resistance 10 1.1.4 Risks related to environmental antibiotic resistance 12 1.2 Fate of antibiotic resistance genes in the aquatic environment 14 1.2.1 Genetic indicators for antibiotic resistance 14 1.2.2 River surface water compartment as dissemination route for antibiotic resistance 15 1.2.3 River biofilm compartment as reservoir for antibiotic resistance 17 1.3 Impact of antibiotics on aquatic microbial communities 18 1.4 Fate and effect of sulfamethoxazole in surface waters 20 2 Scope of the thesis 22 3 Main findings and scientific implications 24 3.1 Fate of antibiotic resistance genes after wastewater discharge into a near-pristine river 24 3.1.1 Wastewater is the primary source for aquatic antibiotic resistance 24 3.1.2 Drought increases the antibiotic resistance prevalence in surface waters 25 3.1.3 Riverbed biofilms serve as local reservoirs for antibiotic resistance genes 26 3.2 Anthropogenic pollution is the key driver for microbial community alteration 26 3.3 Sulfamethoxazole increases the microbial activity of aquatic microbial communities 27 4 Conclusions and future perspective 29 5 References 31 6 Publications 43 6.1 Publication 1 43 6.2 Publication 2 56 6.3 Publication 3 69   7 Appendix 94 7.1 Declaration of independent work 94 7.2 List of publications and conference contributions 95 7.2.1 Publications 95 7.2.2 Conference contributions 96 7.3 Contribution of Co-authors 97 7.4 Curriculum vitae 101 7.5 Acknowledgements 104 7.6 Supplementary Material 105 7.6.1 Supplementary Material for Publication 1 105 7.6.2 Supplementary Material for Publication 2 118 7.6.3 Supplementary Material for Publication 3 125

The main experimental work of this thesis has been a cross-sectional study of the prevalence of refractive error and its biometric correlates in Middle Eastern adults. In addition dynamic accommodative responses and twenty-four hour axial length fluctuations were investigated in young myopic adults. The prevalence of myopia in 3000 Middle Eastern adults (age range 17-40 years) was similar to previously reported levels of myopia in the West. Myopia was associated with a higher level of education, occupations with a high nearwork demand and positive family history of myopia; all of which have been identified as risk factors for myopia development and progression Diurnal variations in axial length (AL) of similar magnitude to those previously reported in emmetropes were observed in myopes recruited in the current thesis. However, the pattern of the diurnal variation in AL was significantly different between early-onset myopes (EOMs) and late-onset myopes (LOMs). There were no significant differences between EOMs and LOMs in the dynamic accommodative response to a sinusoidally oscillating target. The accommodative phase lag was increased following 30 minute adaptation to myopic defocus using +2.00 D lens. However, intense prolonged (30 minute) nearwork was found to have no effect on accommodative gain or phase lag. A number of recommendations for further work on the prevalence of refractive error in the Middle East are suggested along with further research on diurnal AL variations and dynamic accommodative responses in EOMs and LOMs.

Obstructive sleep apnea (OSA) is underrecognized. Between 10% and 69% of preoperative patients have undiagnosed OSA. To reduce the risk of peri-operative complications related to undiagnosed OSA, patients planned to undergo bariatric surgery are screened for OSA. To understand the OSA detection rate with screening practices, the prevalence of OSA within patients who underwent publicly funded bariatric surgery in Ontario between 2010 and 2016 was measured. Secondly, to understand the effect of OSA screening practices on perioperative and longer-term health care costs, health care utilization and costs were compared between patients with OSA and matched patients without OSA in the 30 days post-bariatric surgery, as well as in the 1 year post-bariatric surgery. The Ontario Bariatric Registry (OBR) linked to the ICES health administrative databases were used. A diagnosis of OSA was identified if recorded in the OBR at time of initial bariatric consultation, or if recorded in ICES databases from the bariatric surgery admission records. Costs were calculated based on the “Guidelines on Person-Level Costing Using Administrative Databases in Ontario” using ICES costing algorithms. The overall prevalence of OSA was 47% (95% CI 46% to 47%). Total health care costs per patient, in the 30-day post-operative period, were 1% lower (95% CI 1% to 1%, p < 0.001) in patients with OSA compared to matched patients without OSA. Similarly, at 1 year postbariatric surgery, total health care costs per patient, were 1% lower (95% CI 1% to 1%, p < 0.001) in patients with OSA compared to matched patients without OSA. At 30 days and 1 year, this difference was driven by lower hospitalization-related costs. OSA screening practices at surgical centers in our network led to similar rates of OSA detection as reported in the literature. However, the literature suggests that screening practices lead to missed OSA diagnoses. Further study is required to understand the reduced post-bariatric surgery costs in patients with OSA compared to matched controls without OSA; and, we postulate that missed OSA diagnoses may be a contributor. / Thesis / Master of Science (MSc) / Obstructive sleep apnea (OSA) is underrecognized and a good proportion of patients with OSA are undiagnosed. To reduce the risk of peri-operative complications related to undiagnosed OSA, patients planned to undergo bariatric surgery are screened for OSA. To understand the performance of OSA screening practices, using a province-wide registry, the proportion of patients diagnosed with OSA within patients who underwent publicly-funded bariatric surgery in Ontario between 2010 and 2016 was measured at 47%. Furthermore, to understand the effect of OSA screening practices on peri-operative costs and longer-term health care costs, health care utilization and costs were compared between patients with OSA and matched patients without OSA in the 30 days and 1 year post-bariatric surgery. Total health care costs per patient were 1% lower in patients with OSA compared to patients without OSA, and this difference was driven by lower hospitalization-related costs.

The zoonosis Q fever is caused by the obligate intracellular bacterium Coxiella burnetii. Besides the main transmission route via inhalation of contaminated aerosols, ticks are discussed as vectors since the first isolation of the pathogen from a Dermacentor andersonii tick. The rare detection of C. burnetii in ticks and the difficult differentiation of C. burnetii from Coxiella-like endosymbionts (CLEs) are questioning the relevance of ticks in the epidemiology of Q fever. In this review, literature databases were systematically searched for recent prevalence studies concerning C. burnetii in ticks in Europe and experimental studies evaluating the vector competence of tick species. A total of 72 prevalence studies were included and evaluated regarding DNA detection methods and collectionmethods, country, and tested tick species. Specimens ofmore than 25 different tick species were collected in 23 European countries. Overall, an average prevalence of 4.8% was determined. However, in half of the studies, no Coxiella-DNA was detected. In Southern European countries, a significantly higher prevalence was observed, possibly related to the abundance of different tick species here, namely Hyalomma spp. and Rhipicephalus spp. In comparison, a similar proportion of studies used ticks sampled by flagging and dragging or tick collection from animals, under 30% of the total tick samples derived from the latter. There was no significant difference in the various target genes used for the molecular test. In most of the studies, no distinction was made between C. burnetii and CLEs. The application of specific detection methods and the confirmation of positive results are crucial to determine the role of ticks in Q fever transmission. Only two studies were available, which assessed the vector competence of ticks for C. burnetii in the last 20 years, demonstrating the need for further research.