Gap analyses to assess Canadian readiness for respiratory syncytial virus vaccines: Report from an expert retreat.

Respiratory syncytial virus (RSV) can cause severe disease in infants and older adults. Various vaccine candidates are in development and may become authorized for use in Canada within the next 2-5 years. The Public Health Agency of Canada sought to enhance preparedness for RSV vaccine and passive immunization candidates by organizing an expert retreat to identify knowledge gaps in surveillance and research and development in the context of provincial and territorial RSV public health priorities. We determined that RSV candidate vaccines in development directly address four out of five identified public health priorities, and identified remaining data gaps around vaccine efficacy and effectiveness. We determined that limited or sufficient surveillance data is available to support decision-making for four out of five RSV public health priorities and identified data gaps for several key populations: (i) for RSV cases under 17 years of age, gaps remain for denominator data to calculate incidence and data on medically attended outpatient visits; (ii) for RSV cases in Indigenous and remote communities, gaps remain for data on incidence, prevalence, specific risk factors, feasibility and acceptability; and (iii) for RSV cases in older adults, gaps remain for data on incidence. This process demonstrated the feasibility of, and stakeholder support for, gap analyses in surveillance data to support decisions about prospective vaccines and immune products.

Measles Outbreak with Unique Virus Genotyping, Ontario, Canada, 2015.

The province of Ontario continues to experience measles virus transmissions despite the elimination of measles in Canada. We describe an unusual outbreak of measles in Ontario, Canada, in early 2015 that involved cases with a unique strain of virus and no known association among primary case-patients. A total of 18 cases of measles were reported from 4 public health units during the outbreak period (January 25-March 23, 2015); none of these cases occurred in persons who had recently traveled. Despite enhancements to case-patient interview methods and epidemiologic analyses, a source patient was not identified. However, the molecular epidemiologic analysis, which included extended sequencing, strongly suggested that all cases derived from a single importation of measles virus genotype D4. The use of timely genotype sequencing, rigorous epidemiologic investigation, and a better understanding of the gaps in surveillance are needed to maintain Ontario's measles elimination status.

Trends in prostate cancer incidence and mortality in Canada during the era of prostate-specific antigen screening.

BACKGROUND: Widespread use of prostate-specific antigen (PSA) to screen for prostate cancer began in the early 1990s. Advocates for screening assert that this has caused a decrease in prostate cancer mortality. We sought to describe secular changes in prostate cancer incidence and mortality in Canada in relation to the onset of PSA screening. METHODS: Age-standardized and age-specific prostate cancer incidence (1969-2007) and mortality (1969-2009) from Public Health Agency of Canada databases were analyzed by joinpoint regression. Changes in incidence and mortality were related to introduction of PSA screening. RESULTS: Prior to PSA screening, prostate cancer incidence increased from 54.2 to 99.8 per 100 000 between 1969 and 1990. Thereafter, incidence increased sharply (12.8% per year) to peak at 140.8/100 000 in 1993. After decreasing in all age groups between 1993 and 1996, incidence continued to increase for men aged less than 70 years, but decreased for older men. Age-standardized mortality was stable from 1969 to 1977, increased 1.4% per year to peak in 1995 and subsequently decreased at 3.3% per year; the decline started from 1987 in younger men (age < 60 yr). INTERPRETATION: Incidence was increasing before PSA screening occurred, but rose further after it was introduced. Reductions in prostate cancer mortality began before PSA screening was widely used and were larger than could be anticipated from screening alone. These findings suggest that screening caused artifactual increase in incidence, but no more than a part of reductions in prostate cancer mortality. The reduction may be due to changing treatment or certification of death.

Measles in Canada Between 2002 and 2013.

Background. In 1994, Canada committed to eliminate measles by the year 2000. This report presents the epidemiology of measles in Canada between 2002 and 2013 and its implications in sustaining measles elimination. Methods. Cases included individuals reported to the Canadian Measles and Rubella Surveillance System with confirmed measles. Results. In Canada, 1171 cases of measles were reported between 2002 and 2013 (incidence 0.29 cases per 100 000 population). The annual number of cases ranged from 6 to 752. The majority of cases were unvaccinated (63%) or had an unknown vaccination status (19%). The median age of cases was 14.4 years (range, <1 to 63 years) globally and 14 years when excluding the 2011 outbreak in Quebec where 68% of the 678 cases were 10 to 19 years old. With the exclusion of this outbreak, the incidence was highest in infants (1.0 per 100 000), lower but fairly similar between 1 and 19 years of age (0.2 to 0.4 per 100 000), and there was a substantial decline between 20 and 39 years of age (0.1 per 100 000). There was a significant trend towards a greater annual number of importations over the period. Although importations resulted in no transmission sustained for ≥12 months, 5 chains of transmission had >30 cases. The effective reproductive number between 2002 and 2013 was estimated at 0.86 (95% confidence interval, .81-.92). Conclusions. Canada has maintained elimination between 2002 and 2013, but additional efforts are needed to reduce the proportion of unimmunized individuals and respond to importation events.

Serotype distribution of invasive Streptococcus pneumoniae in Canada during the introduction of the 13-valent pneumococcal conjugate vaccine, 2010.

A baseline serotype distribution was established by age and region for 2058 invasive Streptococcus pneumoniae isolates collected during the implementation period of the 13-valent pneumococcal conjugate vaccine (PCV13) program in many parts of Canada in 2010. Serotypes 19A, 7F, and 3 were the most prevalent in all age groups, accounting for 57% in <2 year olds, 62% in 2-4 year olds, 45% in 5-14 year olds, 44% in 15-49 year olds, 41% in 50-64 year olds, and 36% in ≥65 year olds. Serotype 19A was most predominant in Western and Central Canada representing 15% and 22%, respectively, of the isolates from those regions, whereas 7F was most common in Eastern Canada with 20% of the isolates. Other prevalent serotypes include 15A, 23B, 12F, 22F, and 6C. PCV13 serotypes represented 65% of the pneumococci isolated from <2 year olds, 71% of 2-4 year olds, 61% of 5-14 year olds, 60% of 15-49 year olds, 53% of 50-64 year olds, and 49% of the ≥65 year olds. Continued monitoring of invasive pneumococcal serotypes in Canada is important to identify epidemiological trends and assess the impact of the newly introduced PCV13 vaccine on public health.

Characterization of the Drosophila gene-switch system in aging studies: a cautionary tale.

Genetic studies have shown that in many model organisms, single gene mutations can dramatically influence aging. Systems that allow researchers to control a gene's temporal and spatial expression pattern, known as inducible gene-expression systems, are a valuable asset for the study of the influence of single genes on aging. One inducible gene-expression system reported to allow temporal and tissue-specific control of gene expression in Drosophila is the Gene-Switch system. However, this system has not been extensively characterized in the context of aging research. This report uses six Gene-Switch strains to examine the tissue localization and amount of expression achievable in the major tissue types of the fly. The quantitative analysis of adult flies fed with inducer through life reveals that the levels of expression are influenced by both the inducer concentration and the age of the animal in a strain-specific manner. Furthermore, the relationship between inducer concentration and expression level is unique to each strain and, in some cases, to each gender. The analysis of the spatial expression patterns in several strains revealed expression in more tissue types than previously assumed. Finally, most Gene-Switch strains display expression in the absence of inducer during development and/or during adulthood. These findings have important implications that may reconcile contradictions reported in studies investigating the effects of dFOXO on longevity. This study is an important guide to the design and interpretation of aging studies based on the Gene-Switch system.