Switching from a 2-dose to a 1-dose program of gender-neutral routine vaccination against human papillomavirus in Canada: a mathematical modelling analysis.

Background: Worldwide, countries are examining whether to implement 1-dose human papillomavirus (HPV) vaccination instead of using 2 doses. To inform policy, we sought to project the population-level impact and efficiency of switching from 2-dose to 1-dose gender-neutral routine HPV vaccination in Canada.

Methods: We used HPV-ADVISE, an individual-based transmission-dynamic model of HPV infections and diseases, to mathematically model vaccination programs in 2 provinces, Quebec, a province with high HPV vaccination coverage (around 85%), and Ontario, which has lower coverage (around 65%).

Mechanism of Staple Line Leak After Sleeve Gastrectomy via Isobaric Pressurisation Concentrating Stress Forces at the Proximal Staple Line.

Purpose: Staple line leak following sleeve gastrectomy is a significant problem and has been hypothesised to be related to hyperpressurisation in the proximal stomach. There is, however, little objective evidence demonstrating how these forces could be transmitted to the luminal wall. We aimed to define conditions in the proximal stomach and simulate the transmission of stress forces in the post-operative stomach using a finite element analysis (FEA).

Early Neurodevelopmental Outcomes Following Exposure to General Anesthesia in Infancy: EGAIN, a Prospective Cohort Study.

Background: General anesthesia (GA) is known to worsen neural outcomes in animals, but human research assessing early-life GA exposure and neurodevelopment show inconsistent findings. We investigated the effects of a single GA exposure for minor surgery on the neurodevelopment of healthy children at multiple time-points, using clinical assessments along with behavioral and neurophysiological measures rarely used in human research.

Methods: GA-exposed children were a prospective cohort of 250 full-term, healthy infants who underwent GA for minor surgery before 15 months.

Diagnostic Criteria for Gastro-esophageal Reflux Following Sleeve Gastrectomy.

Background: Gastro-esophageal reflux disease (GERD) post-sleeve gastrectomy (SG) is a controversial issue and diagnostic dilemma. Strong heterogeneity exists in the assessment of reflux post-SG, and better diagnostic tools are needed to characterize symptomatic reflux. We aimed to determine the discriminant factors of symptomatic reflux and establish diagnostic thresholds for GERD following SG.

Pathophysiological Mechanisms of Gastro-esophageal Reflux After Sleeve Gastrectomy.

Objective: To evaluate the mechanisms associated with reflux events after sleeve gastrectomy (SG).

Summary Background Data: Gastro-esophageal reflux (GERD) post-SG is a critical issue due to symptom severity, impact on quality of life, requirement for reoperation, and potential for Barrett esophagus. The pathophysiology is incompletely delineated.

The shifting epidemiology and serotype distribution of invasive pneumococcal disease in Ontario, Canada, 2007-2017.

Background: Ontario, Canada introduced a publicly-funded 13-valent pneumococcal conjugate vaccine (PCV13) for infants in 2010, replacing the 10-valent (PCV10, 2009-2010) and the 7-valent (PCV7, 2005-2009) conjugate vaccine programs; a 23-valent pneumococcal polysaccharide vaccine (PPV23) has been available for older adults since 1996. We examined the epidemiology and serotype distribution of invasive pneumococcal disease (IPD) in Ontario in the context of provincial immunization programs.

Methods: We included confirmed IPD cases reported in Ontario between 2007 and 2017.

The utility of measles and rubella IgM serology in an elimination setting, Ontario, Canada, 2009-2014.

In Canada, measles was eliminated in 1998 and rubella in 2000. Effective measles and rubella surveillance is vital in elimination settings, hinging on reliable laboratory methods. However, low-prevalence settings affect the predictive value of laboratory tests.

The basic reproduction number (R) of measles: a systematic review.

The basic reproduction number, R nought (R), is defined as the average number of secondary cases of an infectious disease arising from a typical case in a totally susceptible population, and can be estimated in populations if pre-existing immunity can be accounted for in the calculation. R determines the herd immunity threshold and therefore the immunisation coverage required to achieve elimination of an infectious disease. As R increases, higher immunisation coverage is required to achieve herd immunity.

Short-Read Whole-Genome Sequencing for Laboratory-Based Surveillance of Bordetella pertussis.

is a Gram-negative bacterium that causes respiratory infections in humans. Ongoing molecular surveillance of acellular vaccine (aP) antigens is critical for understanding the interaction between evolutionary pressures, disease pathogenesis, and vaccine effectiveness. Methods currently used to characterize aP components are relatively labor-intensive and low throughput.

Trends in medical and nonmedical immunization exemptions to measles-containing vaccine in Ontario: an annual cross-sectional assessment of students from school years 2002/03 to 2012/13.

Background: Under Ontario legislation, for select vaccine-preventable diseases nonimmunized or under-immunized students must undergo vaccination or provide a statement of exemption, or risk suspension from school. At the time of this assessment, these diseases included measles, mumps, rubella, diphtheria, tetanus and polio.

Methods: Exemptions data for the school years 2002/03 to 2012/13 were obtained from the Immunization Records Information System used in Ontario.

Global travel patterns and risk of measles in Ontario and Quebec, Canada: 2007-2011.

Background: In 2011 the largest measles outbreak in North America in a decade occurred in Quebec, Canada with over 700 cases. In contrast, measles activity in neighbouring province Ontario remained low (8 cases). Our objective was to determine the extent to which the difference could be explained by differing travel patterns.

Rubella immunity among prenatal women in Ontario, 2006-2010.

Background: Countries of the Americas have been working towards rubella elimination since 2003 and endemic rubella virus transmission appears to have been interrupted since 2009. To contribute towards monitoring of rubella elimination, we assessed rubella seroprevalence among prenatal screening tests performed in Ontario.

Methods: Specimens received for prenatal rubella serologic testing at the Public Health Ontario Laboratory, the provincial reference laboratory, between 2006 and 2010 were analyzed.

Have changing pneumococcal vaccination programmes impacted disease in Ontario?

Background: Publicly funded infant 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in Ontario, Canada in 2005 and was replaced by 10- and 13-valent vaccines (PCV10, PCV13) in October 2009 and November 2010, respectively. Among adults ≥ 65 years, a 23-valent polysaccharide vaccine (PPV23) has been universally available since 1996. In January 2012, PCV13 was approved for adults ≥ 50 years.

Estimating background rates of Guillain-Barré Syndrome in Ontario in order to respond to safety concerns during pandemic H1N1/09 immunization campaign.

Background: The province of Ontario, Canada initiated mass immunization clinics with adjuvanted pandemic H1N1 influenza vaccine in October 2009. Due to the scale of the campaign, temporal associations with Guillain-Barré syndrome (GBS) and vaccination were expected. The objectives of this analysis were to estimate the number of background GBS cases expected to occur in the projected vaccinated population and to estimate the number of additional GBS cases which would be expected if an association with vaccination existed.

An assessment of mumps vaccine effectiveness by dose during an outbreak in Canada.

Background: This investigation was done to assess vaccine effectiveness of one and two doses of the measles, mumps and rubella (MMR) vaccine during an outbreak of mumps in Ontario. The level of coverage required to reach herd immunity and interrupt community transmission of mumps was also estimated.

Methods: Information on confirmed cases of mumps was retrieved from Ontario's integrated Public Health Information System.

CIHI survey: Hospital costs for preterm and small-for-gestational age babies in Canada.

In 2006-2007, more than 54,000 (or one in seven) babies across Canada were born preterm or small for their gestational age (SGA). These babies are often at higher risk for morbidity and mortality than are full-term babies with normal birth weight, and account for a disproportionately high percentage of healthcare costs among newborns. This article highlights key findings from a recent report by the Canadian Institute for Health Information, Too Early, Too Small: A Profile of Small Babies across Canada, and provides information on the hospital costs among low birth weight, preterm and SGA babies.

Syndromic surveillance of gastrointestinal illness using pharmacy over-the-counter sales. A retrospective study of waterborne outbreaks in Saskatchewan and Ontario.

Objective: To ascertain if monitoring over-the-counter (OTC) drug sales could provide a timely syndromic surveillance method of detecting outbreaks of gastrointestinal illness.

Method: This study evaluated the potential of a syndromic surveillance system by comparing retrospective pharmacy OTC sales of anti-nauseants and anti-diarrheals to emergency room visits and case numbers from two Canadian outbreaks related to water contamination by Cryptosporidium, and E.coli O157:H7 and Campylobacter.

A seroprevalence study of west nile virus infection in solid organ transplant recipients.

West Nile virus (WNV) causes severe neurological disease in less than 1% of infections. However, meningoencephalitis may be more common in immunosuppressed transplant patients. In 2002, a WNV outbreak occurred in our region.