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 ava...

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Main Authors: Shinthuja Wijayasri, Kelty Hillier, Gillian H Lim, Tara M Harris, Sarah E Wilson, Shelley L Deeks
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2019-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0226353
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author Shinthuja Wijayasri
Kelty Hillier
Gillian H Lim
Tara M Harris
Sarah E Wilson
Shelley L Deeks
author_facet Shinthuja Wijayasri
Kelty Hillier
Gillian H Lim
Tara M Harris
Sarah E Wilson
Shelley L Deeks
author_sort Shinthuja Wijayasri
collection DOAJ
description 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. We grouped serotypes according to Ontario's current immunization program (PCV13, PPV23, and non-vaccine-preventable) and calculated incidence rates (per 100,000 population) using population data. RESULTS:Between 2007 and 2017, annual incidence of IPD in Ontario ranged between 7.3 and 9.7/100,000 per year. Measures of illness severity were high throughout the period of surveillance. After PCV13 program implementation in 2010, incidence due to PCV13 serotypes decreased significantly across all age groups, with the greatest reductions in children <5 years and adults ≥65 years. Conversely, incidence due to PPV23 unique serotypes increased significantly between 2007 and 2017, with the greatest increases observed in adults 50-64 years (1.4 to 3.5/100,000) and ≥65 years (2.3 to 7.2/100,000). Similar increases were observed in incidence due to non-vaccine-preventable serotypes among all age groups, except infants <1 year. Within specific serotypes, incidence due to serotypes 3 (0.42 to 0.98/100,000) and 22F (0.31 to 0.72/100,000) increased significantly between 2007 and 2017, while incidence due to serotypes 19A and 7F decreased significantly during the PCV13 period (2010-2017). CONCLUSIONS:Eight years after PCV13 implementation in Ontario, our data suggest both direct and indirect effects on serotype-specific incidence in young children and older adults. However, overall provincial rates have remained unchanged, and IPD continues to be a severe burden on the population. The rising incidence of IPD due to PPV23 unique and non-vaccine-preventable serotypes, and the growing burden of serotypes 3 and 22F, require further study.
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spelling doaj.art-3a59a5c3166641dc897def673b4c10082022-12-21T19:13:20ZengPublic Library of Science (PLoS)PLoS ONE1932-62032019-01-011412e022635310.1371/journal.pone.0226353The shifting epidemiology and serotype distribution of invasive pneumococcal disease in Ontario, Canada, 2007-2017.Shinthuja WijayasriKelty HillierGillian H LimTara M HarrisSarah E WilsonShelley L DeeksBACKGROUND: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. We grouped serotypes according to Ontario's current immunization program (PCV13, PPV23, and non-vaccine-preventable) and calculated incidence rates (per 100,000 population) using population data. RESULTS:Between 2007 and 2017, annual incidence of IPD in Ontario ranged between 7.3 and 9.7/100,000 per year. Measures of illness severity were high throughout the period of surveillance. After PCV13 program implementation in 2010, incidence due to PCV13 serotypes decreased significantly across all age groups, with the greatest reductions in children <5 years and adults ≥65 years. Conversely, incidence due to PPV23 unique serotypes increased significantly between 2007 and 2017, with the greatest increases observed in adults 50-64 years (1.4 to 3.5/100,000) and ≥65 years (2.3 to 7.2/100,000). Similar increases were observed in incidence due to non-vaccine-preventable serotypes among all age groups, except infants <1 year. Within specific serotypes, incidence due to serotypes 3 (0.42 to 0.98/100,000) and 22F (0.31 to 0.72/100,000) increased significantly between 2007 and 2017, while incidence due to serotypes 19A and 7F decreased significantly during the PCV13 period (2010-2017). CONCLUSIONS:Eight years after PCV13 implementation in Ontario, our data suggest both direct and indirect effects on serotype-specific incidence in young children and older adults. However, overall provincial rates have remained unchanged, and IPD continues to be a severe burden on the population. The rising incidence of IPD due to PPV23 unique and non-vaccine-preventable serotypes, and the growing burden of serotypes 3 and 22F, require further study.https://doi.org/10.1371/journal.pone.0226353
spellingShingle Shinthuja Wijayasri
Kelty Hillier
Gillian H Lim
Tara M Harris
Sarah E Wilson
Shelley L Deeks
The shifting epidemiology and serotype distribution of invasive pneumococcal disease in Ontario, Canada, 2007-2017.
PLoS ONE
title The shifting epidemiology and serotype distribution of invasive pneumococcal disease in Ontario, Canada, 2007-2017.
title_full The shifting epidemiology and serotype distribution of invasive pneumococcal disease in Ontario, Canada, 2007-2017.
title_fullStr The shifting epidemiology and serotype distribution of invasive pneumococcal disease in Ontario, Canada, 2007-2017.
title_full_unstemmed The shifting epidemiology and serotype distribution of invasive pneumococcal disease in Ontario, Canada, 2007-2017.
title_short The shifting epidemiology and serotype distribution of invasive pneumococcal disease in Ontario, Canada, 2007-2017.
title_sort shifting epidemiology and serotype distribution of invasive pneumococcal disease in ontario canada 2007 2017
url https://doi.org/10.1371/journal.pone.0226353
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