Public Health Agency Of Canada Research Articles

Antenatal Care: A Comparative Review of Guidelines.

Antenatal care plays a crucial role in safely monitoring and ensuring the well-being of both the mother and the fetus during pregnancy, ultimately leading to the best possible perinatal outcomes. The aim of this study was to review and compare the most recently published guidelines on antenatal care. A descriptive review of guidelines from the National Institute for Health and Care Excellence, the Public Health Agency of Canada, the World Health Organization, and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists regarding antenatal care was conducted. There is a consensus among the reviewed guidelines regarding the necessary appointments during the antenatal period, the proper timing for induction of labor, the number and frequency of laboratory examinations for the assessment of mother's well-being, and management strategies for common physiological problems during pregnancy, such as nausea and vomiting, heartburn, pelvic pain, leg cramps, and symptomatic vaginal discharge. In addition, special consideration should be given for mental health issues and timely referral to a specialist, reassurance of complete maternal vaccination, counseling for safe use of medical agents, and advice for cessation of substance, alcohol, and tobacco use during pregnancy. Controversy surrounds clinical evaluation during the antenatal period, particularly when it comes to the routine use of an oral glucose tolerance test and symphysis-fundal height measurement for assessing fetal growth, whereas routine cardiotocography and fetal movement counting are suggested practices only by Royal Australian and New Zealand College of Obstetricians and Gynaecologists. Of note, recommendations on nutritional interventions and supplementation are offered only by Public Health Agency of Canada and World Health Organization, with some minor discrepancies in the optimal dosage. Antenatal care remains a critical factor in achieving positive outcomes, but there are variations depending on the socioeconomic status of each country. Therefore, the establishment of consistent international protocols for optimal antenatal care is of utmost importance. This can help provide safe guidance for healthcare providers and, consequently, improve both maternal and fetal outcomes.

Responding to and managing multijurisdictional outbreaks of COVID-19 in Canadian industrial worksite/work camp settings.

Early in the COVID-19 pandemic, the Public Health Agency of Canada(PHAC) and provincial/territorial(P/T) public health identified the need for a coordinated response to complex multijurisdictional COVID-19 outbreaks. The first large multijurisdictional industrial worksite COVID-19 outbreak highlighted the risk of transmission within these congregate work settings, the risk of transmission to the broader community(ies), and the need to develop setting-specific outbreak response frameworks. PHAC assembled a team to provide national outbreak support for multijurisdictional COVID-19 outbreaks in May 2020. The COVID-19 Outbreak Response Unit (ORU) worked with P/T partners to develop guiding principles for outbreak response and outbreak investigation processes, guidance documents, and investigation tools (e.g., minimum data elements and questionnaires). The ORU, P/T partners, and onsite industrial worksite health and safety staff leveraged outbreak investigation guidelines, industrial worksite outbreak process documents (including minimum data elements), and enhanced case questionnaires to respond to multiple COVID-19 outbreak investigations in industrial worksites. Clear roles/responsibilities and processes, along with standardized data, allowed for more efficient outbreak investigations and earlier implementation of mitigation measures. Multijurisdictional COVID-19 outbreaks highlighted the importance of public health collaboration with industry partners onsite. The assembly of a national outbreak response team was important to facilitate information sharing and provide technical support. Lessons learned and recommendations on outbreak preparation, detection, management, and communication are included to enhance a response framework applicable to future emerging or re-emerging pathogens with epidemic and/or pandemic potential.

Health data social licence: An inclusive process to learn more about the perspectives of experienced public and patient advisors

The term "social licence" has been used to describe which uses and users of health data the public supports - and under what conditions. From November 2022 to January 2023, Health Data Research Network Canada was funded by the Public Health Agency of Canada to explore whether there was consensus among experienced public and patient advisors on: (i) uses of health data that all members supported or opposed and (ii) what constitutes an essential requirement for a health data use or user to be within social licence. The project was conducted in English and French in collaboration with the Interdisciplinary Research Group in Health Informatics (GRIIS) at the University of Sherbrooke. It involved 20 public/patient advisor "participants" and an additional 13 public/patient advisors who served as peer-reviewers, all of whom had prior experience working in a health-related field and/or with health data. The process followed inclusive design principles in that it captured views held by the majority and minority of participants, including views expressed by only one or two participants. After two 2-hour facilitated sessions, participants agreed that it is within social licence for health data to be used (i) by healthcare practitioners to improve patient care, (ii) by governments and administrators to improve the health system, and (iii) by university-based researchers to understand disease and well-being. There was consensus opposition to (i) an individual or organisation selling someone else's identified health data and (ii) health data being used for a purpose that has no public or societal benefit. There was no consensus about what constitutes an essential requirement for a use or users of health data to be with social licence. The results of the process have been published in a non-peer-reviewed report co-authored with participants. This paper has been co-authored with a subset of the participants and peer-reviewers to present a high-level summary of the findings, methodological details, and templates to enable other groups to adapt the process to their own settings. It also presents the results of an anonymous evaluation of the process using the Public and Patient Engagement Evaluation Tool (PPEET), which were mostly positive and identified some areas for improvement.

Prevalence of dementia among people experiencing homelessness in Ontario, Canada: a population-based comparative analysis

Cognitive decline in people experiencing homelessness is an increasingly recognised issue. We compared the prevalence of dementia among people experiencing homelessness to housed individuals in the general population and those living in low-income neighbourhoods. We conducted a population-based, cross-sectional, comparative analysis using linked health-care administrative data from Ontario, Canada. We included individuals aged 45 years or older on Jan 1, 2019, who visited hospital-based ambulatory care (eg, emergency department), were hospitalised, or visited a community health centre in 2019; and identified people experiencing homelessness if they had one or more health-care records with an indication of homelessness or unstable housing. Prevalence of dementia was ascertained as of Dec 31, 2019, using a validated case definition for Alzheimer's disease and related dementia that was modified to include diagnoses made at a community health centre. Poisson models were used to generate estimates of prevalence. Estimates were compared with Ontarians that accessed any of the same health-care services over the same time, overall (general population group), and among those who were in the lowest quintile of area-based neighbourhood income (low-income group). 12 863 people experiencing homelessness, 475 544 people in the low-income comparator group, and 2 273 068 people in the general population comparator group were included in the study. Dementia prevalence was 68·7 per 1000 population among people experiencing homelessness, 62·6 per 1000 population in the low-income group, and 51·0 per 1000 population in the general population group. Descriptively, prevalence ratios between people experiencing homelessness and the comparator groups were highest within the ages of 55-64 years and 65-74 years in both sexes, ranging from 2·98 to 5·00. After adjusting for age, sex, geographical location of residence (urban vs rural), and health conditions associated with dementia, the prevalence ratio of dementia among people experiencing homelessness was 1·71 (95% CI 1·60-1·82) compared with the low-income group and 1·90 (1·79-2·03) compared with the general population group. People experiencing homelessness experience a high burden of dementia compared with housed populations in Ontario. Findings suggest that people experiencing homelessness might experience dementia at younger ages and could benefit from the development of proactive screening and housing interventions. The Public Health Agency of Canada.

National safety monitoring of vaccines from the Canadian Adverse Events Following Immunization Surveillance System (CAEFISS), 2018-2019.

The Canadian Adverse Events Following Immunization Surveillance System (CAEFISS) is a comprehensive vaccine safety surveillance system that includes both passive and active surveillance of vaccines administered in Canada. This work presents a summary of adverse events following immunization (AEFI) nationally for 2018 and 2019. Data extracted from CAEFISS included all AEFI reports received by the Public Health Agency of Canada by April 30, 2022, for vaccines marketed in Canada and administered between January 1, 2018, and December 31, 2019. Descriptive statistics were conducted on AEFI reports by type of surveillance program (i.e., active vs. passive), AEFIs, demographics, healthcare utilization, outcome, seriousness of adverse events and type of vaccine. Between 2018 and 2019, 5,875 AEFI reports were received from across Canada. The average annual AEFI reporting rate was 10.9/100,000 doses distributed in Canada for vaccines administered during 2018-2019 and was found to be inversely proportional to age. The majority of reports (91%) were non-serious events, involving vaccination site reactions, rash and allergic events. Overall, there were 511 serious adverse event reports during 2018-2019. Of the serious adverse event reports, the most common primary AEFIs were anaphylaxis followed by seizure. There were no unexpected vaccine safety issues identified or increases in frequency or severity of adverse events. Canada's continuous monitoring of the safety of marketed vaccines during 2018-2019 did not identify any increase in the frequency or severity of AEFIs, previously unknown AEFIs, or areas that required further investigation or research.

Epidemiological characteristics of human infections with avian influenza A(H5N6) virus, China and Laos: A multiple case descriptive analysis, February 2014-June 2023.

The first human infection with highly pathogenic avian influenza A(H5N6) virus was reported in 2014. From then until June 30, 2023, 85 human cases with confirmed A(H5N6) infection have been reported worldwide. To address the present gap in knowledge of the overall epidemiology of human A(H5N6) infections, the epidemiological characteristics of human infection with A(H5N6) in China from February 2014 to June 2023 are described. Considering the severity of human infections with A(H5N6) virus (case fatality rate: 39%), the increased frequency of case reports from 2021 to present day, and lack of comprehensive epidemiologic analysis of all cases, we conducted a multiple-case descriptive analysis and a literature review to create an epidemiologic profile of reported human cases. Case data was obtained via a literature search and using official intelligence sources captured by the Public Health Agency of Canada's International Monitoring and Assessment Tool (IMAT), including Event Information Site posts from the World Health Organization. Most human A(H5N6) cases have been reported from China (China: 84; Laos: 1), with severe health outcomes, including hospitalization and death, reported among at-risk populations. The majority (84%) of cases reported contact with birds prior to illness onset. Cases were detected throughout the course of the year, with a slight decrease in illness incidence in the warmer months. As A(H5N6) continues to circulate and cause severe illness, surveillance and prompt information sharing is important for creating and implementing effective public health measures to reduce the likelihood of additional human infections.

Risk communication: lessons from an ethnographic, pragmatic, and Canadian regulatory perspective

In a regulatory context, it is important to understand how effective risk communication fits into the overall risk assessment, management, and decision-making process. This includes recognizing the intersections between risk analysis and the 3Ps: policy, politics, and publics, and understanding the barriers to effective communication. Risk communication is especially challenging when it requires the audience to follow and act on authoritative information or advice. Risk communicators must factor attributes such as risk perception, tolerance, and behaviors, and tailor the delivery of messages to diverse audiences. This paper captures the discourse from an intradepartmental workshop on risk communication with participants from Health Canada and the Public Health Agency of Canada. The workshop provided an opportunity to discuss and share references to existing frameworks, pertinent documents, and examples of effective risk communication strategies based on the authors' ethnographic and pragmatic experiences. The workshop aimed to strengthen risk communication by better understanding the value in collaborating with interdisciplinary teams, applying a systems thinking lens, and finding opportunities to experiment and evaluate risk communication strategies for regulatory purposes.

Cross-Sector Collaboration to Improve Access to Community Services for People Living With Diabetes: Contributions From Actor-Network Theory.

Diabetes is a global public health issue. The Public Health Agency of Canada published a Diabetes Framework 2022 which recommends collaborative work across sectors to mitigate the impact of diabetes on health and quality of life. Since 2020, the INMED-COMMUNITY pathway has been implemented in Laval, Québec developing collaboration between healthcare and community sectors through a participatory action research approach. The aim of this article is to gain a better understanding of the INMED-COMMUNITY pathway implementation process, based on the mobilization of network actor theory. Qualitative analysis of semi-structured interviews conducted from January to March 2023 with 12 participants from 3 different sectors (community, health system, research), were carried out using actor-network theory. The results explored the conditions for effective intersectoral collaboration in a participatory action research approach to implement the INMED-COMMUNITY pathway. These were: (1) contextualization of the project, (2) a consultation approach involving various stakeholders, (3) creation of new partnerships, (4) presence of a project coordinator, and (5) mobilization of stakeholders around a common definition of diabetes. Mediation supported by a project coordinator contributed to the implementation of an intersectoral collaborative health intervention, largely due to early identification of controversies.

Treatment of HCV with direct-acting antivirals on reducing mortality related to extrahepatic manifestations: a large population-based study in British Columbia, Canada

HCV infection is associated with mortality due to extrahepatic manifestations (EHM). Sustained virologic response (SVR) following direct-acting antiviral (DAA) therapy has been linked to decreased all-cause and liver-related mortality. However, evidence regarding the impact of DAA on EHM-related deaths is lacking. This study aimed to assess the impact of DAA and SVR on EHM-related mortality. The British Columbia Hepatitis Testers Cohort comprises ∼1.7 million people tested for HCV between 1990 and 2015 and is linked with administrative health data. Among individuals diagnosed with HCV by 12/31/2020, those who received at least one DAA treatment were matched to those who never received treatment by the year of their first HCV RNA positive date. We compared three groups: treated & SVR, treated & no-SVR, and untreated; and generated EHM mortality rates and incidence curves. To account for differences in baseline characteristics, we used inverse probability of treatment weights (IPTW). IPTW-weighted multivariable cause-specific Cox regression models were adjusted for competing risk and confounders. Study population included 12,815 treated (12,287 SVR, 528 no-SVR) and 12,815 untreated individuals (median follow-up 3.4 years, IQR 2.9). The untreated group had the highest EHM mortality rate (30.9 per 1000 person-years [PY], 95% CI 29.2-32.8), followed by the treated & no-SVR group (21.2 per 1000 PY, 95% CI 14.9-30.1), while the treated & SVR group had the lowest EHM mortality rate (7.9 per 1000 PY, 95% CI 7.1-8.7). In the multivariable model, EHM mortality in the treated & SVR group was significantly decreased (adjusted cause-specific hazard ratio [acsHR] 0.20, 95% CI 0.18-0.23). The treated & SVR group had significant reductions in mortality related to each of the EHMs (78-84%). Treatment of HCV with DAA was associated with significant reductions in EHM-related mortality. These findings emphasize the critical importance of timely diagnosis and treatment of HCV to prevent deaths associated with EHM, and have important implications for clinical practice and public health. This work was supported by the BC Centre for Disease Control and the Canadian Institutes of Health Research (CIHR) [Grant # NHC-348216, PJT-156066, and PHE-337680]. DJ has received Doctoral Research Award (#201910DF1-435705-64343) from the Canadian Institutes of Health Research (CIHR) and Doctoral fellowship from the Canadian Network on Hepatitis C (CanHepC). CanHepC is funded by a joint initiative of the Canadian Institutes of Health Research (CIHR) (NHC-142832) and the Public Health Agency of Canada (PHAC).

Risk of sexual transmission of HIV in the context of viral load suppression.

In 2018, the Public Health Agency of Canada (PHAC) published a systematic review to calculate the risk of sexual transmission of human immunodeficiency virus (HIV) in the context of antiretroviral therapy (ART). In 2022, PHAC commissioned the Canadian Agency for Drugs and Technologies in Health (CADTH) to conduct a rapid review of evidence published since 2017. We undertook a meta-analysis of relevant studies from these two reviews. Studies from the rapid review that adequately assessed exposure (HIV viral load) and outcome (HIV seroconversion) were included and assessed for risk of bias (RoB) and certainty of evidence. Results were pooled to estimate the risk of HIV transmission per 100 person-years. Three studies from the rapid review were eligible for inclusion and one was excluded after RoB assessment. In the remaining studies examining risk among people living with HIV who take ART and maintain a suppressed viral load (fewer than 200 copies/mL, measured every 4-6 months), no sexual transmissions of HIV were observed. The pooled incidence estimate based on these studies, and one from the 2018 PHAC review, was zero transmissions/100 person-years (95% CI: 0.00-0.10). No studies in the rapid review provided data on the risk of sexual transmission of HIV in situations of varying levels of viral load. This update highlights the consistency of evidence since the 2018 PHAC review. There remains no evidence of HIV transmission to sexual partners when a person living with HIV is on ART and maintains a suppressed viral load.

Resident Impact of the Single Site Order Restricting Staff Mobility across Long-Term Care Homes in British Columbia, Canada.

The Single Site Order (SSO)-a policy restricting staff from working at multiple long-term care (LTC) homes-was mandated by the Public Health Agency of Canada to control the spread of COVID-19 in LTC homes, where nearly 70% of COVID-19-related deaths in Canada occurred. This mixed methods study assesses the impact of the SSO on LTC residents in British Columbia. Interviews were conducted (residents (n = 6), family members (n = 9), staff (n = 18), and leadership (n = 10) from long-term care homes (n = 4)) and analyzed using thematic analysis. Administrative data were collected between April 2019 and March 2020 and between April 2020 and March 2021 and analyzed using descriptive statistics and data visualization. Qualitative and quantitative data were triangulated and demonstrated that staffing challenges became worse during the implementation of the SSO, resulting in the mental and physical health deterioration of LTC residents. Qualitative data demonstrated decreased time for personalized and proactive care, increased communication challenges, and increased loneliness and isolation. Quantitative data showed a decline in activities of daily living, increased antipsychotic medication use, pressure ulcers, behavioural symptoms, and an increase in falls. Addressing staff workload and staffing shortages during SSO-related policy implementation is essential to avoid resident health deterioration.

93 SARS-CoV-2 Vaccine Acceptance and Uptake among Caregivers of Children 5-11 Years of Age: A Cross-sectional Survey

Abstract Background Although vaccination of children aged 5-11 years against SARS-CoV-2 is recommended in Canada, nearly half of Ontarian children this age remain unvaccinated. Objectives This study aimed to assess caregivers’ vaccine acceptance and uptake for children in this age group and to identify factors associated with vaccine non-acceptance in Ontario. Design/Methods A multi-language self-administered survey was sent to caregivers of children aged 5-11 years through schools and community health centres within the Toronto Area, from April 5th–July 4th, 2022. Socio-demographic characteristics, acceptance of routine childhood and influenza vaccines, and current SARS-CoV-2 vaccine status for parents and older siblings were collected. Data were analyzed using descriptive statistics and multivariable logistic regression. Results Overall, 807 caregivers of children aged 5-11 years answered the survey. Although 748 (93%) caregivers had received at least two doses of COVID-19 vaccine, only 618 (77%) had a child 5-11 years old who had received at least one dose of the vaccine. Adjusted odds ratios for vaccine acceptance were higher among caregivers older than 40 years of age, caregivers who were vaccinated against COVID-19 themselves, children living in areas with high vaccine coverage, and children who received at least one influenza vaccine in the past two years (see Figure 1, below). Caregivers reported seeking information on COVID-19 mostly from public health resources (76%), government organizations (58%), social media (58%), and family doctors or paediatricians (38%). The most common reasons among caregivers not to vaccinate children were concerns about long-term side effects (59%), wanting to wait until there is more experience with vaccinating children (41%), and concerns that vaccines were developed too quickly (39%) (Figure 2). Conclusion We describe factors associated with SARS-CoV-2 vaccine non-acceptance in caregivers of children 5-11 years old and the barriers to vaccine acceptance in this population. These findings provide insights on groups of caregivers that should be targeted for educational and public health interventions and identify parental concerns that ought to be addressed to increase vaccine confidence. Potential competing interests Dr. Shaun K. Morris has received honoraria for lectures from GlaxoSmithKline, was a member of ad hoc advisory boards for Pfizer Canada and Sanofi Pasteur, and is an investigator on an investigator-led grant from Pfizer, all unrelated to this study. This project is supported by a grant from the Public Health Agency of Canada’s Immunization Partnership Fund. 1The number of 668 cases were included in the model.2Caregivers were able to select multiple choices for their ethnicity, and Indigenous ethnic background was classified as mixed and other.3Children received at least one influenza vaccine in the past two years.4Vaccination coverage was based on the Forward Sortation Area from the Institute for Clinical Evaluative Sciences July 2022. 1187 caregivers of unvaccinated children against COVID-19 included and could choose multiple reasons not to vaccinate their children 5-11 years of age.

Discrete separation of patients’ profiles for chronical obstructive pulmonary disease context-aware healthcare efficient systems

According to the Public Health Agency of Canada (PHAC), the symptoms of chronic obstructive pulmonary disease (COPD) are shortness of breath, coughing, and sputum production. Many studies estimate that COPD will become the third-leading cause of death worldwide by 2030 (WHO,2008). Pervasive healthcare systems cover healthcare issues, including chronic diseases; they help patients to manage their own health information and healthcare services at any time and in any place. We developed a COPD healthcare system based on a combination of the parameters of patients. The main goal is to avoid the severe phases of the disease by monitoring them. This combination of risk factors provides in total 600 profiles from data, with 88.5% accuracy. However, many studies have focused on and shown the issues of the effectiveness and accuracy of these systems. The problem is to i apply a new classification model to detect the severe phases of the disease early. Therefore, Instead of working on COPD parameters, we design and validate a profile-based classification model of patients. This model will facilitate the building of a rule-based framework. In addition, the accuracy of our extended COPD system is improved using the classification and separation of patients’ profiles.

Immunological effects and safety of live rotavirus vaccination after antenatal exposure to immunomodulatory biologic agents: a prospective cohort study from the Canadian Immunization Research Network.

People with inflammatory or autoimmune diseases are recommended to continue immunomodulatory biologic agents throughout pregnancy. However, concerns regarding potential immunosuppression in infants exposed to biologic agents have led to recommendations to avoid live vaccines in the first 6-12 months of life. We aimed to examine whether live rotavirus vaccine could be administered safely to infants exposed to biologic agents, assessed in the Canadian Special Immunization Clinic (SIC) Network. In this prospective cohort study, infants exposed to biologic agents in utero were referred to one of six SIC sites in Canada for rotavirus vaccination recommendations. Children with other contraindications to rotavirus vaccination or older than 15 weeks were excluded. Clinical and laboratory evaluations were conducted according to a standard clinical pathway. Data were collected for relevant medical history, pregnancy outcomes, biologic agent exposure history, physical examination, laboratory results of the child, SIC recommendations for rotavirus vaccination, rotavirus vaccine series completion, and adverse events after immunisation. After parental consent, deidentified data were transferred to a central database for analysis. Children recommended for rotavirus vaccination were followed up for 8 months after series initiation to ascertain severe and serious adverse events, including severe diarrhoea, vomiting, and intussusception. Between May 1, 2017, and Dec 31, 2021, 202 infants were assessed and 191 eligible infants were enrolled (97 [51%] were female and 94 [49%] were male). When including those exposed to multiple agents, the most common biologic agents to which infants were exposed were infliximab (67 [35%] of 191), adalimumab (49 [26%]), ustekinumab (18 [9%]), and vedolizumab (17 [9%]). Biologic agent exposure continued into the third trimester for 178 (93%) infants. No clinically significant abnormalities in lymphocyte subsets, quantitative immunoglobulins, or mitogen responses were detected. After SIC assessment, rotavirus vaccination was recommended for 187 (98%) of 191 infants, all of whom were followed up. By end of follow-up on Aug 19, 2022, 168 (90%) infants had initiated rotavirus vaccination; 150 (80%) completed the series. No serious adverse events after immunisation were reported, but three (2%) infants required medical attention, one for vomiting and change in stools who was subsequently diagnosed with gastroesophageal reflux disease, one for rash on labia unrelated to vaccination, and one for vomiting and diarrhoea associated with a milk allergy. Findings from this study suggest that lymphocyte subsets and the safety of live rotavirus vaccination are generally not affected by in-utero exposure to biologic agents. Rotavirus vaccination can be offered to infants exposed to anti-TNF agents in utero. Public Health Agency of Canada and Canadian Institutes of Health Research through the Canadian Immunization Research Network.

Canada’s National Advisory Committee on immunization: Adaptations and challenges during the COVID-19 pandemic

The COVID-19 pandemic has challenged traditional vaccine guidance infrastructure and frameworks, and added urgency and complexity to the operation of National Immunization Technical Advisory Groups (NITAGs).Canada’s National Advisory Committee on Immunization (NACI) provides immunization guidance to the Public Health Agency of Canada (PHAC) who publicly shares expert and evidence-informed guidance with Canadian provinces and territories. Throughout the pandemic, NACI and PHAC implemented many adaptations to meet urgent needs for pandemic vaccine guidance.In this paper, we describe: structural adaptations in response to the accelerated pace and amount of work required to issue recommendations that were timed around product authorizations and dynamic epidemiology; technical adaptations in response to rapidly evolving evidence of variable quality which required close monitoring, and which promoted reliance on basic vaccine principles due to incomplete direct evidence; the need to provide nimble advice (e.g., off-label recommendations, preferential recommendations); communications adaptations (e.g. identify sustainable spokespeople for the committee, receive stakeholder feedback, and ensure urgent nuanced advice was communicated to a diverse audience); and research adaptations focussing on solutions to constrained supply (e.g. prioritisation, extended intervals, and heterologous schedules). The early pandemic vaccine experience has created a roadmap of lessons and adaptations that should be leveraged in future pandemic vaccine programs, and has highlighted the essential role of NITAGs to complement regulatory structures during pandemics to ensure timely, impactful, and evidence-informed public health vaccine guidance.

Early Omicron infection is associated with increased reinfection risk in older adults in long-term care and retirement facilities

Older adults are at increased risk of SARS-CoV-2 Omicron infection and severe disease, especially those in congregate living settings, despite high SARS-CoV-2 vaccine coverage. It is unclear whether hybrid immunity (combined vaccination and infection) after one Omicron infection provides increased protection against subsequent Omicron reinfection in older adults. Incidence of SARS-CoV-2 Omicron infection was examined in 750 vaccinated residents of long-term care and retirement homes in the observational cohort COVID in Long-Term Care Study in Ontario, Canada, within a 75-day period (July to September 2022). Risk of infection was assessed by Cox proportional hazards regression. Serum anti-spike and anti-RBD SARS-CoV-2 IgG and IgA antibodies, microneutralization titres, and spike-specific T cell memory responses, were examined in a subset of 318 residents within the preceding three months. 133 of 750 participants (17.7%) had a PCR-confirmed Omicron infection during the observation period. Increased infection risk was associated with prior Omicron infection (at 9-29 days: 47.67 [23.73-95.76]), and this was not attributed to days since fourth vaccination (1.00 [1.00-1.01]) or residence outbreaks (>6 compared to ≤6: 0.95 [0.37-2.41]). Instead, reinfected participants had lower serum neutralizing antibodies to ancestral and Omicron BA.1 SARS-CoV-2, and lower anti-RBD IgG and IgA antibodies, after their initial Omicron infection. Counterintuitively, SARS-CoV-2 Omicron infection was associated with increased risk of Omicron reinfection in residents of long-term care and retirement homes. Less robust humoral hybrid immune responses in older adults may contribute to risk of Omicron reinfection. COVID-19 Immunity Task Force of the Public Health Agency of Canada.

Validating the Children's Intrinsic Needs Satisfaction Scale in the 2019 Canadian Health Survey on Children and Youth.

The Public Health Agency of Canada monitors the psychological and social well-being of Canadian youth using the Children's Intrinsic Needs Satisfaction Scale (CINSS). Validation analyses of the CINSS have been conducted, but not in the 2019 Canadian Health Survey on Children and Youth (CHSCY), a more recent and representative national survey with a different sampling frame, collection method and other measured outcomes. This study tested the validity of the CINSS in the 2019 CHSCY. Data were collected in all provinces and territories from February 11 to August 2, 2019. The CINSS was administered to respondents aged 12 to 17 years and was designed to assess relatedness, autonomy and competence at home, at school and with friends. Descriptive statistics for CINSS items and subscales were obtained. Confirmatory factor analysis (CFA) was conducted to test how well a correlated traits correlated uniqueness (CTCU) model fit the CINSS data. Associations with mental health and other psychosocial variables were examined. In general, items within the CINSS were correlated in expected ways, and support was found for a CTCU model in the CFA. While response distributions on the CINSS items were skewed, the CINSS subscales had acceptable internal consistency and were associated with self-rated mental health, happiness, life satisfaction, perceived stress, bullying victimization and behaviour problems in line with expectations. This study supports the validity of the CINSS. Inclusion of the CINSS in future youth health surveys would allow for continued public health surveillance of the psychological and social well-being of youth in Canada.

Surveillance for Ixodes scapularis and Ixodes pacificus ticks and their associated pathogens in Canada, 2020.

Ixodes scapularis and Ixodes pacificus ticks are the principal vectors of the agent of Lyme disease and several other tick-borne diseases in Canada. Tick surveillance data can be used to identify local tick-borne disease risk areas and direct public health interventions. The objective of this article is to describe the seasonal and spatial characteristics of the main Lyme disease vectors in Canada, and the tick-borne pathogens they carry, using passive and active surveillance data from 2020. Passive and active surveillance data were compiled from the National Microbiology Laboratory Branch (Public Health Agency of Canada), provincial and local public health authorities, and eTick (an online, image-based platform). Seasonal and spatial analyses of ticks and their associated pathogens are presented, including infection prevalence estimates. In passive surveillance, I. scapularis (n=7,534) were submitted from all provinces except Manitoba and British Columbia, while I. pacificus (n=718) were submitted only from British Columbia. No ticks were submitted from the Territories. The seasonal distribution of I. scapularis submissions was bimodal, but unimodal for I. pacificus. Four tick-borne pathogens were identified in I. scapularis (Borrelia burgdorferi, Anaplasma phagocytophilum, Babesia microti and Borrelia miyamotoi) and one in I. pacificus (B. miyamotoi). In active surveillance, I. scapularis (n=688) were collected in Ontario, Québec and New Brunswick. Five tick-borne pathogens were identified: B. burgdorferi, A. phagocytophilum, B. microti, B. miyamotoi and Powassan virus. This article provides a snapshot of the distribution of I. scapularis and I. pacificus and their associated human pathogens in Canada in 2020, which can help assess the risk of exposure to tick-borne pathogens in different provinces.

Investigation of acute severe hepatitis in children: A review of liver transplant data, Canada, 2021-2022.

An increase in severe acute hepatitis of unknown etiology was first reported in the United Kingdom in April 2022. Following this report, the Public Health Agency of Canada connected with three paediatric liver transplant centres across Canada to determine if an increase in liver transplants was noted. Data demonstrated no observable increase in the number of transplants conducted in 2022. These data in conjunction with a federal, provincial, territorial investigation provided insight into the situation in Canada.

Clinical Characteristics and Outcomes Among Travelers With Severe Dengue : A GeoSentinel Analysis.

Dengue virus is a flavivirus transmitted by Aedes mosquitoes and is an important cause of illness worldwide. Data on the severity of travel-associated dengue illness are limited. To describe the epidemiology, clinical characteristics, and outcomes among international travelers with severe dengue or dengue with warning signs as defined by the 2009 World Health Organization classification (that is, complicated dengue). Retrospective chart review and analysis of travelers with complicated dengue reported to GeoSentinel from January 2007 through July 2022. 20 of 71 international GeoSentinel sites. Returning travelers with complicated dengue. Routinely collected surveillance data plus chart review with abstraction of clinical information using predefined grading criteria to characterize the manifestations of complicated dengue. Of 5958 patients with dengue, 95 (2%) had complicated dengue. Eighty-six (91%) patients had a supplemental questionnaire completed. Eighty-five of 86 (99%) patients had warning signs, and 27 (31%) were classified as severe. Median age was 34 years (range, 8 to 91 years); 48 (56%) were female. Patients acquired dengue most frequently in the Caribbean (n= 27 [31%]) and Southeast Asia (n= 21 [24%]). Frequent reasons for travel were tourism (46%) and visiting friends and relatives (32%). Twenty-one of 84 (25%) patients had comorbidities. Seventy-eight (91%) patients were hospitalized. One patient died of nondengue-related illnesses. Common laboratory findings and signs were thrombocytopenia (78%), elevated aminotransferase (62%), bleeding (52%), and plasma leakage (20%). Among severe cases, ophthalmologic pathology (n= 3), severe liver disease (n= 3), myocarditis (n= 2), and neurologic symptoms (n= 2) were reported. Of 44 patients with serologic data, 32 confirmed cases were classified as primary dengue (IgM+/IgG-) and 12 as secondary (IgM-/IgG+) dengue. Data for some variables could not be retrieved by chart review for some patients. The generalizability of our observations may be limited. Complicated dengue is relatively rare in travelers. Clinicians should monitor patients with dengue closely for warning signs that may indicate progression to severe disease. Risk factors for developing complications of dengue in travelers need further prospective study. Centers for Disease Control and Prevention, International Society of Travel Medicine, Public Health Agency of Canada, and GeoSentinel Foundation.