Canada communicable disease report = Releve des maladies transmissibles au Canada最新文献

The coronavirus disease 2019 (COVID-19) pandemic has disproportionately affected seniors living in congregate living settings. The evolving surveillance context has led to novel use of wastewater surveillance to monitor levels of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in these settings. This study presents a pilot of upstream congregate living wastewater surveillance of SARS-CoV-2 for the detection of COVID-19 outbreaks and the effects of early public health interventions. We monitored localized wastewater SARS-CoV-2 levels from four congregate living settings March 15, 2021 to October 1, 2022 and correlated these levels with suspected and confirmed COVID-19 outbreaks determined by other methods. We identified five wastewater signals that correlated with confirmed outbreaks and three wastewater signals that did not correlate with subsequent outbreaks. In the five confirmed outbreaks, the wastewater signal was detected 2-10 days (median, five days) prior to confirmation of the outbreak by case testing. This pilot demonstrates upstream sampling for SARS-CoV-2 in wastewater may effectively detect outbreaks prior to their detection through symptomatic case testing and could support a balanced approach to outbreak response in congregate living settings, leading to increased wellbeing of these residents.

Background: The human immunodeficiency virus (HIV) epidemic has disproportionately affected African, Caribbean and Black (ACB) communities in Canada. We investigated the prevalence and factors associated with HIV infection among ACB people in Ontario.

Methods: A cross-sectional survey of first- and second-generation ACB people aged 15-64 years in Toronto and Ottawa (Ontario, Canada). We collected sociodemographic information, self-reported HIV status and offered dried blood spot (DBS) testing to determine the prevalence of HIV infection. Factors associated with HIV infection were investigated using regression models.

Results: A total of 1,380 people were interviewed and 834 (60.4%) tested for HIV. The HIV prevalence was 7.5% overall (95% confidence interval [CI] 7.1-8.0) and 6.6% (95% CI 6.1-7.1) in the adult population (15-49 years). Higher age (adjusted odds ratio [aOR] 2.8; 95% CI 2.77-2.82), birth outside of Canada (aOR 4.7; 95% CI 1.50-14.71), French language (aOR 9.83; 95% CI 5.19-18.61), unemployment (aOR 1.85; 95% CI 1.62-2.11), part-time employment (aOR 4.64; 95% CI 4.32-4.99), substance use during sex (aOR 1.66; 95% CI 1.47-1.88) and homosexual (aOR 19.68; 95% CI 7.64-50.71) and bisexual orientation (aOR 2.82; 95% CI 1.19-6.65) were associated with a positive HIV test. Those with a high school (aOR 0.01; 95% CI 0.01-0.02), college (aOR 0.00; 95% CI 0.00-0.01) or university education (aOR 0.00; 95% CI 0.00-0.01), more adequate housing (aOR 0.85; 95% CI 0.82-0.88), a higher social capital score (aOR 0.61; 95% CI 0.49-0.74) and a history of sexually transmitted infections (aOR 0.40; 95% CI 0.18-0.91) were less likely to have a positive HIV test.

Conclusion: Human immunodeficiency virus infection is linked to sociodemographic, socioeconomic, and behavioural factors among ACB people in Ontario.

Background: The Laboratory Incident Notification Canada surveillance system monitors laboratory incidents that are mandated to be reported under the Human Pathogens and Toxins Act and the Human Pathogens and Toxins Regulations. This article describes laboratory exposure incidents that occurred in Canada in 2021 and individuals affected in these incidents.

Methods: We extracted all laboratory incidents occurring in licensed Canadian laboratories in 2021 from the Laboratory Incident Notification Canada system and analyzed them using the software R. We calculated the rate of exposure incidents and performed descriptive statistics by sector, root cause, activity, occurrence type and type of pathogen/toxin. Analysis of the education level, route of exposure, sector, role and laboratory experience of the affected persons was also conducted. We conducted seasonality analysis to compare the median monthly occurrence of exposure incidents between 2016 and 2020 to monthly incidents in 2021.

Results: Forty-three exposure incidents involving 72 individuals were reported to Laboratory Incident Notification Canada in 2021. There were two confirmed laboratory-acquired infections and one suspected infection. The annual incident exposure rate was 4.2 incidents per 100 active licenses. Most exposure incidents involved non-Security Sensitive Biological Agents (n=38; 86.4%) and human risk group 2 (RG2) pathogens (n=27; 61.4%), with bacteria (n=20; 45.5%) and viruses (n=16; 36.4%) as the most implicated agent types. Microbiology was the most common activity associated with these incidents (n=18; 41.9%) and most incidents were reported by the academic sector (n=20; 46.5%). Sharps-related (n=12; 22.2%) incidents were the most common, while human interaction (e.g. workload constraints/pressures/demands, human error) (n=29, 28.2%) was the most common root cause. Most affected individuals were exposed through inhalation (n=38; 52.8%) and worked as technicians or technologists (n=51; 70.8%). Seasonality analyses revealed that the number of exposure incidents reported in 2021 were highest in September and May.

Conclusion: The rate of laboratory incidents was slightly lower in 2021 than in 2020. The most common occurrence type was sharps-related while issues with human interaction was the most cited root cause.

Background: : The coronavirus disease 2019 (COVID-19) pandemic has placed unprecedented demands on local public health units in Ontario, Canada, one of which was the need for in-house epidemiological modelling capabilities. The objective of this study is to develop a native Windows desktop app for epidemiological modelling, to be used by public health unit epidemiologists to predict COVID-19 transmission in Durham Region.

Methods: : The developed app is an implementation of a multi-stratified compartmental epidemiological model that can accommodate multiple virus variants and levels of vaccination, as well as public health measures such as physical distancing, contact tracing followed by quarantine and testing followed by isolation. It was used to investigate the effects of different factors on COVID-19 transmission, including vaccination coverage, vaccine effectiveness, waning of vaccine-induced immunity and the advent of the Omicron variant. The simulation start date was November 22, 2021.

Results: : For the Delta variant, at least 90% of the population would need to be vaccinated to achieve herd immunity. A Delta-variant-only epidemiological curve would be flattened from the start in the absence of immunity waning and within six months in the presence of immunity waning. The percentage of infections caused by the Omicron variant was forecast to increase from 1% to 97% in the first month of the simulation. Total Omicron infections were forecasted to be reduced, respectively, by 26% or 41% if 3,000 or 5,000 booster doses were administered per day.

Conclusion: : For the Delta variant, both natural and vaccination-induced immunity are necessary to achieve herd immunity, and waning of vaccine-induced immunity lengthens the time necessary to reach herd immunity. In the absence of additional public health measures, a wave driven by the Omicron variant was predicted to pose significant public health challenges with infections predicted to peak in 2-3 months from the start of the simulation, depending on the rate of administration of booster doses.

The coronavirus disease 2019 (COVID-19) pandemic has exacerbated social inequities along ethnic, racial and socio-economic lines, with significant harmful consequences for children. Building on the lessons learned from community-based initiatives, this commentary proposes a reflection around equity, diversity, and inclusion challenges embedded in child vaccination campaigns during an emergency context. We argue that building equitable and inclusive practices around marginalized communities' child vaccination is a multifaceted challenge. Beyond good intentions-wanting to protect children-the risks and benefits associated with highlighting diversity in each intervention need to be carefully considered, especially when it comes to a contested/polarizing procedure such as vaccination with a novel type of vaccine. Often, a one-size-fits-all approach negates and perpetuates structural inequities. In other cases, highlighting diversity and inequities may inadvertently increase stigma and discrimination, and further harm or infantilize targeted communities. By providing multiple perspectives, a transdisciplinary approach can support decision-making in a crisis context.

Canadian seasonal influenza circulation had been suppressed since the beginning of the coronavirus disease 2019 (COVID-19) pandemic. This suppression was reported globally and generated concern that the return of community influenza circulation could be intense and that co-circulation of influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was possible and potentially severe. Community circulation of influenza returned to Canada during the 2021-2022 influenza season. The influenza epidemic began in week 16 (mid-April 2022) and lasted only nine weeks. This epidemic was driven by influenza A(H3N2) and was exceptionally late in the season, low in intensity and short in length. Community co-circulation of influenza and SARS-CoV-2 was observed in Canada for the first time during the 2021-2022 seasonal influenza epidemic. The unusual characteristics of the 2021-2022 influenza epidemic suggest that a breadth of factors moderate transmission dynamics of the two viruses. Concerns of an intense seasonal influenza epidemic did not come to fruition during the 2021-2022 season; therefore, high influenza susceptibility remains, as does predisposition to larger influenza epidemics. Ongoing circulation of SARS-CoV-2 creates uncertainty about dynamics of future influenza epidemics, but influenza vaccination remains a key public health intervention available to protect Canadians. Public health authorities need to remain vigilant, maintain surveillance and continue to plan for both heightened seasonal influenza circulation and for the potential for endemic co-circulation of influenza and SARS-CoV-2.

Background: A coronavirus disease 2019 (COVID-19) community outbreak was declared October 5-December 3, 2020, in the Restigouche region of New Brunswick, Canada. This article describes the epidemiological characteristics of the outbreak and assesses factors associated with its transmission in rural communities, informing public health measures and programming.

Methods: A provincial line list was developed from case and contact interviews. Descriptive epidemiological methods were used to characterize the outbreak. Incidence rates among contacts, and by gender for the regional population were estimated.

Results: There were 83 laboratory-confirmed cases of COVID-19 identified during the observation period. The case ages ranged from 10-89 years of age (median age group was 40-59 years of age) and 51.2% of the cases were male. Symptom onset dates ranged from September 27-October 27, 2020, with 83% of cases being symptomatic. A cluster of early cases at a social event led to multiple workplace outbreaks, though the majority of cases were linked to household transmission. Complex and overlapping social networks resulted in multiple exposure events and that obscured transmission pathways. The incidence rate among men was higher than women, men were significantly more likely to have transmission exposure at their workplace than women, and men were the most common index cases within a household. No transmission in school settings among children was documented despite multiple exposures.

Conclusion: This investigation highlighted the gendered nature and complexity of a COVID-19 outbreak in a rural Canadian community. Targeted action at workplaces and strategic messaging towards men are likely required to increase awareness and adherence to public health measures to reduce transmission in these settings.

Background: Non-pharmaceutical interventions (NPIs) aim to reduce the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections mostly by limiting contacts between people where virus transmission can occur. However, NPIs limit social interactions and have negative impacts on economic, physical, mental and social well-being. It is, therefore, important to assess the impact of NPIs on reducing the number of coronavirus disease 2019 (COVID-19) cases and hospitalizations to justify their use.

Methods: Dynamic regression models accounting for autocorrelation in time series data were used with data from six Canadian provinces (British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Québec) to assess 1) the effect of NPIs (measured using a stringency index) on SARS-CoV-2 transmission (measured by the effective reproduction number), and 2) the effect of the number of hospitalized COVID-19 patients on the stringency index.

Results: Increasing stringency index was associated with a statistically significant decrease in the transmission of SARS-CoV-2 in Alberta, Saskatchewan, Manitoba, Ontario and Québec. The effect of stringency on transmission was time-lagged in all of these provinces except for Ontario. In all provinces except for Saskatchewan, increasing hospitalization rates were associated with a statistically significant increase in the stringency index. The effect of hospitalization on stringency was time-lagged.

Conclusion: These results suggest that NPIs have been effective in Canadian provinces, and that their implementation has been, in part, a response to increasing hospitalization rates of COVID-19 patients.

Background: In 2019, the human immunodeficiency virus (HIV) and hepatitis C (HCV) diagnosis rates in Saskatchewan (SK) were approximately twice the national rate. To address these high levels, Saskatchewan Stories, a community-based digital database, was developed to make information on Saskatchewan-based HIV and HCV programs, projects and initiatives (PPI) centrally and freely available. To begin populating this database, we conducted an environmental scan representing HIV and HCV PPI from January 1, 1980 to May 31, 2020.

Methods: MedLine, ERIC, ProQuest One Literature, Public Health Information database, SCOPUS and CINAHL were searched for both HIV and HCV articles. In addition, Bibliography of Native North Americans was searched for HIV and EMBSE (Ovid) and Indigenous studies portal (iPortal) were searched for HCV articles. Google Canada, Government of Saskatchewan, and Government of Canada websites were also searched.

Results: In total, 139 HIV-specific PPI and 29 HCV-specific PPI were found in the environmental scan (n=168). Among HIV PPI, 27% (n=38) were from academic literature while 73% (n=101) were from grey literature. Among HCV PPI, 41% (n=12) were from academic literature, while 59% (n=17) were from grey literature. HIV accounted for 83% of total PPI, compared to 17% for HCV.

Conclusion: This environmental scan is an important contribution to evidence-based practice and research in SK. It is particularly useful for organizations, researchers, policymakers and people living with HIV/HCV to develop new evidence-based PPI, to secure funding for PPI and to support individuals and communities in SK affected by HIV and HCV.

Background: Invasive group A streptococcal (iGAS) disease (caused by Streptococcus pyogenes) has been a nationally notifiable disease in Canada since 2000. This report summarizes the demographics, emm types and antimicrobial resistance of iGAS infections in Canada in 2020.

Methods: The Public Health Agency of Canada's National Microbiology Laboratory (Winnipeg, Manitoba) collaborates with provincial and territorial public health laboratories to conduct national surveillance of invasive S. pyogenes. Emm typing was performed on all isolates using the Centers for Disease Control and Prevention emm sequencing protocol. Antimicrobial susceptibilities were determined using Kirby-Bauer disk diffusion according to Clinical and Laboratory Standards Institute guidelines. Population-based iGAS disease incidence rates up to 2019 were obtained through the Canadian Notifiable Disease Surveillance System.

Results: Overall, the incidence of iGAS disease in Canada has increased from 4.0 to 8.1 cases per 100,000 population from 2009 to 2019. The 2019 incidence represents a slight decrease from the 2018 rate of 8.6 cases per 100,000 population. A total of 2,867 invasive S. pyogenes isolates that were collected during 2020 are included in this report, representing a decrease from 2019 (n=3,194). The most common emm types in 2020 were emm49 (16.8%, n=483) and emm76 (15.0%, n=429), both increasing significantly in prevalence since 2016 (p<0.001). The former most prevalent type, emm1, decreased to 7.6% (n=217) in 2020 from 15.4% (n=325) in 2016. Antimicrobial resistance rates in 2020 included 11.5% resistance to erythromycin, 3.2% resistance to clindamycin and 1.6% nonsusceptibility to chloramphenicol.

Conclusion: Though the number of collected invasive S. pyogenes isolates decreased slightly in 2020 in comparison to previous years, iGAS disease remains an important public health concern. The emm distribution in Canada has been subtly shifting over the past five years, away from common and well-known emm1 and towards emm49 and emm76. It is important to continue surveillance of S. pyogenes in Canada to monitor expanding replacement emm types, as well as outbreak clones and antimicrobial resistance.