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

Background: Cutaneous larva migrans (CLM) is one of the most common dermatoses affecting travellers to the tropics.

Objective: To describe demographic and travel correlates of travellers returning to Canada from the Caribbean with CLM over a 10-year pre-pandemic period.

Methods: Demographic and travel-related data on ill travellers encountered either during or after completion of their travel/migration and seen in any of eight CanTravNet sites from January 1, 2009, to December 31, 2018, with a final diagnosis of CLM were extracted and analyzed. During this time, access to first-line therapy, ivermectin, was available via Health Canada's Special Access Programme.

Results: Of 17,644 travellers presenting to CanTravNet over the enrolment period, 328 (1.9%) returned from the Caribbean with CLM. The median age of travellers with CLM was 34 years (interquartile range: 25-50 years), with females accounting for 58% of cases. Ninety-five percent (n=313) travelled for tourism. Jamaica was the most common source country, with 216 cases (67%), followed by Barbados (n=27, 8%) and the Dominican Republic (n=23, 7%). Cases in 2018 were imported predominantly from Jamaica (n=58, 73%) and the Dominican Republic (n=12, 15%). Age, sex and purpose of travel were similar across years. The percentage of all imported cases of CLM that originated from the Caribbean increased from 9% in 2016 to 24.5% in 2018.

Conclusion: Proportions and absolute numbers of CLM in travellers returning to Canada from the Caribbean are increasing. Improved awareness of this common dermatosis among physicians and travellers, as well as improved access to effective therapies, will reduce associated morbidity.

Background: In 2021, approximately 77% of active tuberculosis (TB) disease (TBD) cases in Canada were among foreign-born individuals. Less than 3% of TBD cases in Canada are detected through pre-arrival Canadian immigration medical examinations (i.e., chest X-rays), and the remaining 97% are likely due to reactivation of undiagnosed latent TB infection (TBI) post-arrival. In New Brunswick, the proportion of TBD cases among foreign-born individuals gradually increased from about 33% (1/3 individuals) in 2013 to 100% (14/14 individuals) in 2023. The objective of this study was to estimate the prevalence of TBI among immigrants in southern New Brunswick, identify potential predictors for positive TBI screening and assess participant experiences with the pilot TBI screening procedure.

Methods: A cross-sectional study was conducted from November 2021 to November 2023 among immigrants ≥19 years old who had no history of TBD and were born in a country with a TB incidence rate of ≥40/100,000 population or were referred by healthcare professionals. Participants were recruited through various channels and underwent TBI screening using the interferon-gamma release assay, followed by a survey on their screening experience.

Results: Of the 264 participants, 49 (18.6%) screened positive for TBI. Factors associated with higher odds of screening TBI-positive included birthplace in a "highly to severely endemic" (≥300/100,000 population) TB-incidence country (OR=3.24; 95% CI: 1.07-9.81) and increased age (OR=1.05; 95% CI: 1.01-1.08). Participants rated the pilot TBI screening procedure positively (mean scores ranged from 4.03-4.55 on a five-point Likert scale).

Conclusion: Results suggest that immigrants born in countries with TB incidences of ≥300/100,000 population should be considered for screening and treatment of TBI. The pilot TBI screening procedure yielded positive feedback. Further research with a larger sample is recommended.

Background: The current avian influenza A(H5N1) epizootic poses a significant threat to public health, with sporadic infections in humans raising concerns about potential adaptation for efficient human transmission. Laboratory studies have provided evidence that the polymerase basic protein 2 (PB2) E627K mutation facilitates more efficient replication in mammals and humans. This mutation has been detected in Canadian poultry, wild birds and mammals.

Objective: Our objective was to summarize the current state of evidence on the impact of the avian influenza PB2 E627K mutation on human adaptation, transmission, epidemiology and clinical outcomes in natural human infections.

Methods: We employed a search strategy across MEDLINE, Embase, Scopus, Global Health and CAB Abstracts for articles published from each database's inception until mid-May 2023.

Results: We identified nine eligible articles for review that addressed human transmission or adaptation (n=5), epidemiological or clinical implication (n=1) or both topics (n=3). Some studies suggested that the PB2 E627K mutation may play a role in zoonotic transmission from birds to humans, with studies indicating its association with parallel evolution and positive selection in A(H5) and A(H7) viruses. Other studies presented analyses that supported the notion of an increased fatality rate among cases with the PB2 E627K mutation, highlighting its potential role as a virulence factor.

Conclusion: The association of the PB2 E627K mutation with human adaptation, transmission and increased fatality rates highlights the importance of genomic surveillance under One Health umbrella. Further research is warranted to explore the role of this mutation and determine how it interacts with other mutations.

Background: In April of 2024, studies in the United States (US) identified the presence of influenza A(H5N1) viral RNA in 20%-40% of commercially available pasteurized milk in the US, suggesting that cattle infections were widespread across the country.

Methods: As an initial assessment of the situation in Ontario, 117 samples of pasteurized cow's milk purchased from retail outlets in Ontario in April and May of 2024 were tested for the presence of influenza A viral RNA.

Results: No influenza A viral RNA was detected.

Conclusion: The Canadian Food Inspection Agency has subsequently developed an ongoing surveillance system for testing commercially available pasteurized milk and raw milk at processing plants in Canada.

Background: Over the past ten years, there has been a steady increase in the reported rates of gonorrhea and chlamydia in Canada, with gonorrhea rising by 171% and chlamydia by 26%.

Objective: To collect and synthesize national and international chlamydia and gonorrhea screening guidelines to inform the revision of the current Public Health Agency of Canada (PHAC) recommendations.

Methods: A scan of published chlamydia and gonorrhea screening guidelines of high-income countries was conducted. Guidelines were appraised using the Appraisal of Guidelines for Research & Evaluation II (AGREE II) and PROGRESS-Plus tools.

Results: A total of 17 guidelines on chlamydia and gonorrhea screening published between 2015 and 2023 were included in this review. The overall score of the AGREE II methodological assessment ranged from a rating of three to seven out of seven points. Only one guideline fully met the considerations identified in the assessment tool. Most international organizations recommend universal screening for chlamydia, and a few organizations recommend opportunistic screening and targeted/risk-based screening. As for gonorrhea screening, organizations mostly recommend targeted/risk-based screening and a few organizations recommend universal screening. None of the international gonorrhea guidelines recommended opportunistic screening. The implementation of universal screening has been shown to have minimal negative impact on the individuals being screened, while increasing testing rates. Most guidelines recommend screening individuals <25 years of age, while only two organizations recommend screening individuals <30 years of age.

Conclusion: The findings of this review will be used to inform the revision of the current PHAC recommendations on chlamydia and gonorrhea screening, which will be published in early 2025. International organizations recommend either universal or opportunistic screening. The majority of Canadian provinces and territories follow PHAC's Sexually Transmitted and Blood-Borne Infections: Guides for Health Professionals and recommend universal screening for individuals <25 years of age.

Background: In Canada, gonorrhea is the second most prevalent sexually transmitted bacterial infection. The Gonococcal Antimicrobial Surveillance Programme-Canada (GASP-Canada), a passive surveillance system monitoring antimicrobial resistance in Neisseria gonorrhoeae in Canada since 1985, is the source for this summary of demographics, antimicrobial resistance and N. gonorrhoeae multi-antigen sequence typing (NG-MAST) of gonococcal isolates collected in Canada in 2022.

Objective: To summarize the antimicrobial resistance trends and molecular types of N. gonorrhoeae cultures in Canada from 2018 to 2022. These trends inform the federal, provincial and territorial guidelines for treatment of gonorrhea.

Methods: Provincial and territorial public health laboratories submitted N. gonorrhoeae cultures and data to the National Microbiology Laboratory in Winnipeg as part of the surveillance system. The antimicrobial resistance and molecular type of each isolate received were determined.

Results: In total, 3,855 N. gonorrhoeae cultures were identified and tested across Canada in 2022, a 12.1% increase since 2021 (n=3,439). Decreased susceptibility to cefixime declined in 2022 (0.3%) compared to 2018 (0.5%). Decreased susceptibility to ceftriaxone also declined between 2018 (0.6%) and 2022 (0.3%). Azithromycin resistance was similar in 2022 (8.1%) to what it was in 2018 (7.6%). In 2022, NG-MAST-17972 (13.3%) was the most prevalent sequence type in Canada.

Conclusion: The spread of antimicrobial-resistant gonorrhea is a significant public health concern. The continued regional and national surveillance of antimicrobial resistance in N. gonorrhoeae is essential in ensuring effective treatment therapies are recommended.

Background: A variety of methods, including self-report and antibody testing, has been used to estimate the prevalence of SARS-CoV-2 infections and related longer-term symptoms, but the impact of employed methods on conclusions has not been thoroughly explored.

Objective: We examined associations between self-report and antibody findings in the Canadian adult (aged 18 years and older) population.

Methods: We used data from a large population-based cross-sectional probability survey conducted between April and August 2022. Self-reported infection status and experiences with common longer-term COVID-19 symptoms since the start of the pandemic was collected, as well as a dried blood spot to measure SARS-CoV-2 antibodies.

Results: As of August 2022, the number of adults reported having had a confirmed or suspected infection was 37.9% (95% CI: 36.8%-39.1%), while the overall mean probability of having infection-related antibodies was 52.9% (95% CI: 51.8%-54.0%) and increased with respondent certainty they had been infected. However, the mean probability of having infection-related antibodies was not associated with infection severity or the reporting of common longer-term COVID-19 symptoms. More than one in five adults were unaware they had been infected.

Conclusion: Self-report surveys may misclassify the SARS-CoV-2 infection status of a substantial proportion of untested people and may bias estimates of the percentage infected, the severity of infections and the risk of developing infection-related longer-term symptoms. Common longer-term COVID-19 symptoms reported by some could have been caused by other infections or diseases.

Background: Immunization programs for the prevention of respiratory syncytial virus (RSV) in infants have been available in Canada since the authorization of palivizumab in 2002. However, these programs have been limited to only those infants at highest risk for severe RSV disease. The authorization of new passive immunizing products to prevent RSV, including a new monoclonal antibody (nirsevimab) and a vaccine administered in pregnancy (RSV pre-fusion stabilized F protein; RSVpreF) offers the opportunity to prevent RSV in more Canadian infants. The objective of this article is to summarize guidance from the National Advisory Committee on Immunization (NACI) on the prevention of RSV in infants.

Methods: NACI established key policy questions and performed an evidence review and synthesis. NACI made evidence-based recommendations in consideration of the burden of illness to be prevented, safety and efficacy of the new immunizing products, economic evidence and ethics, equity, feasibility, and acceptability.

Results: Nirsevimab and RSVpreF offer protection against severe outcomes of RSV disease, including hospitalization and intensive care unit admission. Nirsevimab protection may be slightly higher and may last longer than protection offered by RSVpreF. Nirsevimab and RSVpreF also have a similar frequency of adverse reactions for both pregnant and infant participants. The RSVpreF vaccine may increase the risk of severe local adverse events compared to placebo for pregnant recipients. In RSVpreF clinical trials, an imbalance was observed in late preterm birth between RSVpreF and placebo recipients. It is unclear whether there is a causal relation with the vaccine as the currently available data is inconclusive.

Conclusion: Based on new evidence, NACI recommends building towards a universal RSV immunization program for all infants. Currently, nirsevimab is preferred over RSVpreF. Program introduction could occur in stages depending on access to supply, cost effectiveness, and affordability of available options.

Background: The Global Public Health Intelligence Network (GPHIN) is an event-based surveillance platform that collects thousands of pieces of open-source information, including international news media, across multiple languages on a daily basis. Analysts have observed that news media reporting in some languages tended to use more sensational wording to describe major health events. There has been minimal research exploring potential differences in sensationalism in international news media reporting to confirm these observations.

Objective: This exploratory study assessed the differences in the level of sensationalism in early international news media reporting of COVID-19 through a mixed-methods analysis.

Methods: Relevant news media articles received in GPHIN seven days following the Public Health Emergency of International Concern declaration of COVID-19 by the World Health Organization were extracted for screening and analysis. An adapted tool was used to measure the sensationalism of pandemic-related health news. Deductive thematic analysis was conducted to examine themes of sensationalism. Differences in prevalence of sensationalism in news media reporting by language and country/territory of publication were assessed. Sentiment analysis assessed the sentiment and emotional tone of the news media articles.

Results: Of 951 news articles that met the eligibility criteria, 155 contained sensationalism. There were significant differences between languages (French, Russian and Spanish) and various domains of sensationalism. This study also found a more negative emotional tone in news media articles with sensationalism.

Conclusion: This exploratory study showed that language has the potential to impact the perception of health events using more sensationalized language.