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Background: For accessing dental care in Canada, approximately 62% of the population has employment-based insurance, 6% have some publicly funded coverage, and 32% have to pay out-of pocket. Those with no insurance or public coverage find dental care more unaffordable compared to those with private insurance. To support the development of more comprehensive publicly funded dental care programs, it is important to understand the socio-demographic attributes of all those, who find dental care unaffordable. Methods: This study is a secondary analysis of the data collected from Ontarians during the latest available cycle of the Canadian Community Health Survey (2017-18), a cross-sectional survey that collects information on health status, health care utilization, and health determinants for the Canadian population. First, bivariate analysis was conducted to determine the characteristics of Ontarians who lack dental insurance. Afterwards, we employed machine learning (ML) to analyze data and identify risk indicators for not having private dental insurance. Specifically, we trained several supervised ML models and utilized Shapley additive explanations (SHAP) to determine the relative feature importance for not having private dental insurance from the best ML model [the gradient boosting (GBM)]. Results: Approximately one-third of Ontarians do not have private insurance coverage for dental care. Individuals with an income below $20,000, those unemployed or working part-time, seniors aged above 70, and those unable to afford to have their own housing are more at risk of not having private dental insurance, leading to financial barriers in accessing dental care. Conclusion: In the future, government-funded programs can incorporate these identified risk indicators when determining eligible populations for publicly funded dental programs. Understanding these attributes is critical for developing targeted and effective interventions, ensuring equitable access to dental care for Canadians. [ABSTRACT FROM AUTHOR]

The introduction of pneumococcal conjugate vaccines has led to the emergence of non-vaccine serotypes, which contributed to invasive pneumococcal disease in Canada and worldwide. A significant increase in the prevalence of non-13-valent pneumococcal conjugate vaccine (PCV-13)-included serotypes 22F, 15A, and 8 was observed from 2009 to 2013 in Ontario (all p values < 0.01). In this study, whole genome sequencing was conducted on the 25 isolates of serotype 22F, seven of 15A and 10 of 8 to investigate the population structure and antibiotic resistance. All seven serotype 15A isolates were found to be multidrug resistant. From whole genome analysis, we observed recombination events among serotypes 22F, 15A and 8 populations. Serotype 22F (ST433) has emerged into two sub-populations, with 28% (7/25) exhibiting recombination events, and five also acquiring macrolide resistance as a result of recombination. This study enhances the knowledge on the molecular evolution of emerging non-PCV-13 vaccine serotype 22F, including acquisition of resistance genes through recombination events. It underpins the importance of whole genome sequencing in studying Streptococcus pneumoniae population structures and dynamics, and its utility in molecular surveillance. [ABSTRACT FROM AUTHOR]

Abstract: A mechanistic model of the tick vector of Lyme disease, Ixodes scapularis, was adapted to a deterministic structure. Using temperature normals smoothed by Fourier analysis to generate seasonal temperature-driven development rates and host biting rates, and a next generation matrix approach, the model was used to obtain values for the basic reproduction number () for I. scapularis at locations in southern Canada where the tick is established and emerging. The at Long Point, Point Pelee and Chatham sites where I. scapularis are established, was estimated at 1.5, 3.19 and 3.65, respectively. The threshold temperature conditions for tick population survival () were shown to be the same as those identified using the mechanistic model (2800–3100 cumulative annual degree days ), and a map of for I. scapularis, the first such map for an arthropod vector, was drawn for Canada east of the Rocky Mountains. This map supports current risk assessments for Lyme disease risk emergence in Canada. Sensitivity analysis identified host abundance, tick development rates and summer temperatures as highly influential variables in the model, which is consistent with our current knowledge of the biology of this tick. The development of a deterministic model for I. scapularis that is capable of providing values for is a key step in our evolving ability to develop tools for assessment of Lyme disease risk emergence and for development of public health policies on surveillance, prevention and control. [Copyright &y& Elsevier]

Background: Papillary urothelial neoplasm of low malignant potential (PUN-LMP) was introduced as a noninvasive, noncancerous lesion and a separate grade category in 1998. Subsequently, PUN-LMP was reconfirmed by World Health Organization (WHO) 2004 and WHO 2016 classifications for urothelial bladder tumors., Objectives: To analyze the proportion of PUN-LMP diagnosis over time and to determine its prognostic value compared to Ta-LG (low-grade) and Ta-HG (high-grade) carcinomas. To assess the intraobserver variability of an experienced uropathologist assigning (WHO) 2004/2016 grades at 2 time points., Materials and Methods: Individual patient data of 3,311 primary Ta bladder tumors from 17 hospitals in Europe and Canada were available. Transurethral resection of the tumor was performed between 1990 and 2018. Time to recurrence and progression were analyzed with cumulative incidence functions, log-rank tests and multivariable Cox-regression stratified by institution. Intraobserver variability was assessed by examining the same 314 transurethral resection of the tumorslides twice, in 2004 and again in 2018., Results: PUN-LMP represented 3.8% (127/3,311) of Ta tumors. The same pathologist found 71/314 (22.6%) PUN-LMPs in 2004 and only 20/314 (6.4%) in 2018. Overall, the proportion of PUN-LMP diagnosis substantially decreased over time from 31.3% (1990-2000) to 3.2% (2000-2010) and to 1.1% (2010-2018). We found no difference in time to recurrence between the three WHO 2004/2016 Ta-grade categories (log-rank, P = 0.381), nor for LG vs. PUN-LMP (log-rank, P = 0.238). Time to progression was different for all grade categories (log-rank, P < 0.001), but not between LG and PUN-LMP (log-rank, P = 0.096). Multivariable analyses on recurrence and progression showed similar results for all 3 grade categories and for LG vs. PUN-LMP., Conclusions: The proportion of PUN-LMP has decreased to very low levels in the last decade. Contrary to its reconfirmation in the WHO 2016 classification, our results do not support the continued use of PUN-LMP as a separate grade category in Ta tumors because of the similar prognosis for PUN-LMP and Ta-LG carcinomas., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background & Aims: There is controversy over the effects of direct-acting antiviral (DAA) therapies for hepatitis C virus (HCV) infection on hepatocellular carcinoma (HCC) recurrence and tumor aggressiveness. We compared HCC recurrence patterns between DAA-treated and untreated HCV-infected patients who had achieved a complete response to HCC treatment in a North American cohort., Methods: We conducted a retrospective cohort study of patients with HCV-related HCC with a complete response to resection, local ablation, transarterial chemo- or radioembolization, or radiation therapy from January 2013 through December 2017 at 31 health systems throughout the United States and Canada. Cox regression was used to examine the association between DAA therapy and time to recurrence after a complete response, with DAA therapy analyzed as a time-varying exposure. We also estimated the association between DAA therapy and risk of early HCC recurrence (defined as 365 days after complete response)., Results: Of 793 patients with HCV-associated HCC, 304 (38.3%) received DAA therapy and 489 (61.7%) were untreated. HCC recurred in 128 DAA-treated patients (42.1%; early recurrence in 52 patients) and 288 untreated patients (58.9%; early recurrence in 227 patients). DAA therapy was not associated with HCC recurrence (hazard ratio 0.90, 95% confidence interval 0.70-1.16) or early HCC recurrence (hazard ratio 0.96, 95% confidence interval 0.70-1.34) after we adjusted for study site, age, sex, Child-Pugh score, α-fetoprotein level, tumor burden, and HCC treatment modality. In DAA-treated and untreated patients, most recurrences were within the Milan criteria (74.2% vs 78.8%; P = .23). A larger proportion of DAA-treated than untreated patients received potentially curative HCC therapy for recurrent HCC (32.0% vs 24.6%) and achieved a complete or partial response (45.3% vs 41.0%) but this did not achieve statistical significance., Conclusion: In a large cohort of North American patients with complete response to HCC treatment, DAA therapy was not associated with increased overall or early HCC recurrence. HCC recurrence patterns, including treatment response, were similar in DAA-treated and untreated patients., (Copyright © 2019 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background: The extent to which climate change may affect human health by increasing risk from vector-borne diseases has been under considerable debate., Objectives: We quantified potential effects of future climate change on the basic reproduction number (R0) of the tick vector of Lyme disease, Ixodes scapularis, and explored their importance for Lyme disease risk, and for vector-borne diseases in general., Methods: We applied observed temperature data for North America and projected temperatures using regional climate models to drive an I. scapularis population model to hindcast recent, and project future, effects of climate warming on R0. Modeled R0 increases were compared with R0 ranges for pathogens and parasites associated with variations in key ecological and epidemiological factors (obtained by literature review) to assess their epidemiological importance., Results: R0 for I. scapularis in North America increased during the years 1971-2010 in spatio-temporal patterns consistent with observations. Increased temperatures due to projected climate change increased R0 by factors (2-5 times in Canada and 1.5-2 times in the United States), comparable to observed ranges of R0 for pathogens and parasites due to variations in strains, geographic locations, epidemics, host and vector densities, and control efforts., Conclusions: Climate warming may have co-driven the emergence of Lyme disease in northeastern North America, and in the future may drive substantial disease spread into new geographic regions and increase tick-borne disease risk where climate is currently suitable. Our findings highlight the potential for climate change to have profound effects on vectors and vector-borne diseases, and the need to refocus efforts to understand these effects.