Publications by authors named "Wijayasri S"
Article Synopsis
- New vaccine products for invasive pneumococcal disease (IPD) were authorized in Canada, prompting a study to examine trends in IPD incidence and severity in Ontario across different time periods, including pre- and post-vaccine introduction and during the COVID-19 pandemic.
- The analysis revealed a decline in IPD incidence and hospitalizations among children under 5 years after the introduction of the 13-valent vaccine (PCV13), but an increase in case fatality rates and hospitalizations among older adults.
- Despite the overall decrease in cases from PCV13 serotypes, there was a rise in cases from newer serotypes, highlighting the need for ongoing surveillance and possible adjustments to vaccination strategies.
Introduction: Identifying and monitoring adverse events following vaccination contributed to the safety and effectiveness of COVID-19 mass vaccination campaigns. In March 2021, international reports emerged of an adverse event following vaccination with adenovirus vector COVID-19 vaccines (ChAdOx1-S [recombinant] and Ad26.COV2.
View Article and Find Full Text PDFThe COVID-19 pandemic has stimulated wastewater-based surveillance, allowing public health to track the epidemic by monitoring the concentration of the genetic fingerprints of SARS-CoV-2 shed in wastewater by infected individuals. Wastewater-based surveillance for COVID-19 is still in its infancy. In particular, the quantitative link between clinical cases observed through traditional surveillance and the signals from viral concentrations in wastewater is still developing and hampers interpretation of the data and actionable public-health decisions.
View Article and Find Full Text PDFBackground: 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.
Background: Lyme disease is an infection caused by the spirochete and, in most of North America, is transmitted by the blacklegged tick . Climate change has contributed to the expansion of the geographic range of blacklegged ticks in Ontario, increasing the risk of Lyme disease for Ontarians.
Objective: To identify the number of cases and incidence rates, as well as the geographic, seasonal and demographic distribution of Lyme disease cases reported in Ontario in 2017, with comparisons to historical trends.
Background: In Canada, the annual incidence rates of West Nile virus (WNV) illness have fluctuated over the last 15 years. Ontario is one of the provinces in Canada most affected by WNV and, as a result, has implemented robust mosquito and human surveillance programs.
Objective: To summarize and discuss the epidemiology of WNV illness in Ontario, Canada in 2017, with comparisons to previous years.
Background: Invasive pneumococcal disease (IPD) causes significant morbidity in Canada, yet even with routine surveillance, it is difficult to interpret current IPD trends in serotype distribution and antimicrobial resistance. The enhanced Invasive Pneumococcal Disease Surveillance System (eIPDSS) pilot project was designed to facilitate a better understanding of IPD trends at the national level by linking epidemiologic and laboratory (epi-lab) data.
Objectives: To evaluate the eIPDSS by assessing five attributes (usefulness, data quality, simplicity, acceptability and timeliness) and to develop recommendations for future national IPD surveillance.