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

Background: Seasonal influenza infection can lead to serious complications and adverse outcomes for pregnant individuals, the developing fetus and infants younger than six months of age. This supplemental statement provides an evidence summary on the safety and effectiveness of influenza vaccination in pregnant individuals, and the benefits and risks to the pregnant person, the developing fetus and infants younger than six months of age.

Methods: A systematic review was conducted on the effectiveness and safety of influenza vaccination in pregnancy. The National Advisory Committee on Immunization (NACI)'s evidence-based process was used to assess the quality of eligible studies, summarize and analyze the findings, and apply an ethics, equity, feasibility and acceptability lens to develop recommendations.

Results: The evidence suggests that influenza vaccination during pregnancy is effective in reducing the risk of laboratory-confirmed influenza infection and hospitalization in both pregnant individuals and their infants up to six months postpartum. The evidence also suggests that influenza vaccination during pregnancy does not increase the risk of non-obstetric serious adverse events in pregnant persons, infant death, spontaneous abortion, stillbirth, preterm birth, small for gestational age, low birth weight and congenital anomalies.

Conclusion: Based on this body of evidence, NACI reaffirms the safety and importance of influenza vaccination during pregnancy. NACI recommends that individuals at any stage of pregnancy should receive an age-appropriate inactivated, unadjuvanted or recombinant influenza vaccine each influenza season. Influenza vaccination may be given at the same time as, or at any time before or after administration of another vaccine, including the coronavirus disease 2019 (COVID-19) or pertussis vaccines.

Background: 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.

Objective: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

Background: Passive immunization products for infants and pregnant women and people have sparked interest in understanding Canada's respiratory syncytial virus (RSV) burden. This rapid review examines RSV burden of disease in infants, young children and pregnant women and people.

Methods: Electronic databases were searched to identify studies and systematic reviews reporting data on outpatient visits, hospitalizations, intensive care unit admissions, deaths and preterm labour associated with RSV. We also contacted Canadian respiratory virus surveillance experts for additional data.

Results: Overall, 17 studies on infants and young children and 10 studies on pregnant women and people were included, in addition to primary surveillance data from one Canadian territory (Yukon). There were higher rates of medical utilization for infants than older children. Hospitalization rates were highest in infants under six months (more than 1% annually), with 5% needing intensive care unit admission, but mortality was low. Severe outcomes often occurred in healthy full-term infants and burden was higher than influenza. Respiratory syncytial virus attack rate was 10%-13% among pregnant women and people. Only one study found a higher hospitalization rate in pregnant women and people compared to non-pregnant women and people. Limited evidence was found on intensive care unit admission, death and preterm birth for pregnant women and people.

Conclusion: While risk of severe outcomes is larger in high-risk infants and children, healthcare burden is greatest in healthy term infants. The RSV severity for pregnant women and people appears to be similar to that for non-pregnant women and people.

Background: The coronavirus disease 2019 (COVID-19) pandemic has highlighted the need to improve the safety of the environments where we care for older adults in Canada. After providing assistance during the first wave, many Ontario hospitals formally partnered with local congregate care homes in a "hub and spoke" model during second pandemic wave onward. The objective of this article is to describe the implementation and longitudinal outcomes of residents in one hub and spoke model composed of a hospital partnered with 18 congregate care homes including four long-term care and 14 retirement or other congregate care homes.

Intervention: Homes were provided continuous seven-day per week access to hospital support, including infection prevention and control (IPAC), testing, vaccine delivery and clinical support as needed. Any COVID-19 exposure or transmission triggered a same-day meeting to implement initial control measures. A minimum of weekly on-site visits occurred for long-term care homes and biweekly for other congregate care homes, with up to daily on-site presence during outbreaks.

Outcomes: Case detection among residents increased following implementation in context of increased testing, then decreased post-immunization until the Omicron wave when it peaked. After adjusting for the correlation within homes, COVID-related mortality decreased following implementation (OR=0.51, 95% CI, 0.30-0.88; p=0.01). In secondary analysis, homes without pre-existing IPAC programs had higher baseline COVID-related mortality rate (OR=19.19, 95% CI, 4.66-79.02; p<0.001) and saw a larger overall decrease during implementation (3.76% to 0.37%-0.98%) as compared to homes with pre-existing IPAC programs (0.21% to 0.57%-0.90%).

Conclusion: The outcomes for older adults residing in congregate care homes improved steadily throughout the COVID-19 pandemic. While this finding is multifactorial, integration with a local hospital partner supported key interventions known to protect residents.

Background: The ongoing coronavirus disease 2019 (COVID-19) pandemic has necessitated novel testing strategies, including the use of rapid antigen tests (RATs). The widespread distribution of RATs to the public prompted Peterborough Public Health to launch a pilot RAT self-report tool to assess its utility in COVID-19 surveillance. The objective of this study is to investigate the utility of RAT using correlations between RAT self-report results and other indicators of COVID-19.

Methods: We investigated the association between RAT results, PCR test results and wastewater levels of nmN1N2 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genes (to infer COVID-19 levels) using Pearson's correlation coefficient. Percent positivity and count of positive tests for RATs and polymerase chain reaction (PCR) tests were analyzed.

Results: The PCR percent positivity and wastewater were weakly correlated (r=0.33, p=0.022), as were RAT percent positivity and wastewater nmN1N2 levels (r=0.33, p=0.002). The RAT percent positivity and PCR percent positivity were not significantly correlated (r=-0.035, p=0.75). Count of positive RATs and count of positive PCR tests were moderately correlated (r=0.59, p<0.001). Wastewater nmN1N2 levels were not significantly correlated with either count of positive RATs (r=0.019, p=0.864) or count of positive PCR tests (r=0.004, p=0.971).

Conclusion: Our results support the use of RAT self-reporting as a low-cost simple adjunctive COVID-19 surveillance tool, and suggest that its utility is greatest when considering an absolute count of positive RATs rather than percent positivity due to reporting bias towards positive tests. These results can help inform COVID-19 surveillance strategies of local public health units and encourage the use of a RAT self-report tool.

The coronavirus disease 2019 pandemic served as a compelling modern-day reminder of the value of early warning against communicable disease threats in public health. As countries exit the acute phase of the pandemic, there remains a continued need to be vigilant for potential communicable disease threats, particularly as the risk of animal-to-human spillover events is increasing due to climate and land use change. Early warning of emerging threats facilitates earlier public health response, which affords more time to implement public health measures that can help minimize the impact of a particular health threat and protect the health and well-being of the population. One approach to providing early warning for communicable disease and other threats is through event-based surveillance (EBS). However, EBS is not often discussed in the context of public health surveillance. This overview introduces EBS and how it might contribute to providing early warning for communicable disease threats.

Background: Lyme disease (LD) emerged in southern Québec at the start of the century, with many municipalities now endemic. A coordinated active surveillance programme has been in place in the province of Québec since 2014, including a limited number of sentinel field sites resampled each year and a larger set of accessory field sites that change yearly according to the LD surveillance signal. We aimed to evaluate whether a sentinel approach to active surveillance was more representative of LD risk to human populations, compared to risk-based surveillance.

Methods: We compared enzootic hazard measures (average nymph densities) from sentinel and accessory sites with LD risk (number of human LD cases) across the study area between 2015 and 2019 using local bivariate Moran's I analysis.

Results: Hazard measures from sentinel sites captured spatial risk significantly better than data from accessory sites (χ²=20.473, p<0.001). In addition, sentinel sites successfully tracked the interannual trend in LD case numbers, whereas accessory sites showed no association despite the larger sample size.

Conclusion: Where surveillance aims to document changes in tick-borne disease risk over time and space, we suggest that repeated sampling of carefully selected field sites may be most effective, while risk-based surveillance may be more usefully applied to confirm the presence of emerging disease risk in a specific region of interest or to identify suitable sites for long-term monitoring as LD and other tick-borne diseases continue to emerge.

Background: From March 2020 to January 2021, Newfoundland and Labrador experienced 408 coronavirus disease 2019 (COVID-19) cases (incidence 78 per 100,000). In February and March 2021, a community outbreak of the B.1.1.7 (Alpha) variant occurred in the Eastern Regional Health Authority. This article describes the epidemiology of this variant of concern outbreak, identifies settings that likely contributed to spread and informs recommendations for public health measures (PHMs).

Methods: Provincial surveillance data were linked with case interview data and a school class roster. Descriptive epidemiological methods were used to characterize the outbreak. Secondary attack rates (SAR) were calculated for households and classrooms.

Results: This outbreak involved 577 laboratory-confirmed and 38 probable cases. Whole genome sequencing determined cases were B.1.1.7. The median age was 31 years and the highest proportion of cases were in the 15 to 19-year age group (29%); 293 (51%) were female and 140 (24%) were asymptomatic upon identification. Early cases were linked to a high school, sports activities, a restaurant and social gatherings. As the outbreak progressed, cases were associated with household transmission, a daycare, healthcare settings and a workplace. The unadjusted SAR estimate among laboratory-confirmed cases was 24.4% for households and 19.3% for classroom exposures. When adjusted for other potential exposures, SAR estimates were 19.9% for households and 11.3% for classrooms.

Conclusion: This outbreak demonstrated how B.1.1.7 spread rapidly through a community with previously low COVID-19 transmission and few preventative PHMs in place. Implementation and compliance with school and community-based PHMs is critical for preventing transmission during outbreaks.

Background: Tecovirimat (TCV, TPOXX^®) is an orthopox-specific antiviral drug indicated for the treatment of smallpox. There is also a mechanistic basis for its use in mpox infection. However, its approval was based on animal studies, and its efficacy and side-effect profile in human patients with disease is unknown.

Methods: During the 2022 international mpox epidemic, clinicians in Canada accessed TCV from the Public Health Agency of Canada's National Emergency Strategic Stockpile for severe cases of mpox disease. We describe the use of TCV in nine adults with severe mpox virus infection in Montréal, Canada.

Results: Five patients were treated for severe and potentially life-threatening head and neck symptoms, while four were treated for genitourinary or anorectal disease. Two-thirds of patients were also treated for suspected bacterial superinfection. All patients recovered (median time to resolution of severe symptoms: nine days) without relapse or hospital readmission. No patients reported adverse events attributable to TCV and no patients stopped their treatment early.

Conclusion: Our experience suggests that TCV is well tolerated and may accelerate recovery in severe cases. These preliminary, observational data may also be explained by concomitant treatment for superinfection and are limited by the absence of a control group. Controlled, clinical trials should be conducted to clarify the attributable benefit of TCV in severe mpox infection.

Background: Age and certain medical/social conditions are risk factors for invasive pneumococcal disease (IPD). For prevention of IPD, the National Advisory Committee on Immunization (NACI) has recommended the 23-valent polysaccharide pneumococcal vaccine, PNEU-P-23, for adults 65 years of age and older and adults over 18 years of age living with certain underlying conditions. NACI has also recommended 13-valent conjugate pneumococcal vaccine, PNEU-C-13, for adults; however, in publicly funded programs, this recommendation is limited to individuals with risk factors for IPD. Two new conjugate vaccines, PNEU-C-15 and PNEU-C-20, have been authorized by Health Canada for prevention of IPD in adults. This article summarizes NACI public health recommendations for pneumococcal vaccines in adults given these new conjugate vaccines that provide additional serotype coverage over PNEU-C-13.

Methods: Key studies evaluating the immunogenicity and safety of PNEU-C-15 and PNEU-C-20 were reviewed. The Grading of Recommendations, Assessment, Development and Evaluations framework methodology was used to assess the certainty of evidence.

Results: The PNEU-C-15 and PNEU-C-20 vaccines showed comparable immune responses, and safety profiles for all mild, moderate, and severe adverse events, to the currently used vaccines. No data were available on the efficacy or effectiveness of PNEU-C-15 or PNEU-C-20. Economic evidence and feasibility assessments supported the use of the PNEU-C-20 vaccine.

Conclusion: NACI recommends PNEU-C-20 for adults 65 years of age and older, 50-64 years of age and living with factors placing them at higher risk of pneumococcal disease, and 18-49 years of age with immunocompromising conditions, with PNEU-C-15+PNEU-P-23 an alternative.