RESUMO
Background: Invasive pneumococcal disease (IPD, Streptococcus pneumoniae) has been a nationally notifiable disease in Canada since 2000. The use of conjugate vaccines has caused a shift in the distribution of serotypes over time. This report is a summary of the demographics, serotypes and antimicrobial resistance of IPD isolates collected in Canada in 2021 and 2022. Methods: The National Microbiology Laboratory (NML) of the Public Health Agency of Canada in Winnipeg, Manitoba collaborates with provincial and territorial public health laboratories to conduct national surveillance of IPD. There were 1,999 isolates reported in 2021 and 3,775 isolates in 2022. Serotype was determined by the Quellung reaction or whole-genome sequencing (WGS). Antimicrobial susceptibilities were determined by WGS methods, broth microdilution, or data shared by collaborators in the Canadian Antimicrobial Resistance Alliance program at the University of Manitoba. Population-based IPD incidence rates were obtained through the Canadian Notifiable Disease Surveillance System. Results: The incidence of IPD in Canada was 5.62 cases per 100,000 population in 2021, decreasing from the peak of 10.86 cases per 100,000 population in 2018. Serotypes with increasing trends (p<0.05) between 2018 and 2022 included: 4 (6.1%-12.4%), 9V (1.0%-5.1%) and 12F (4.8%-5.4%). The overall prevalence of PCV13 serotypes increased over the same period (31.2%-41.5%, p<0.05) while the prevalence of non-vaccine types decreased significantly (27.3%-21.5%, p<0.0001). The highest rates of antimicrobial resistance in 2021 and 2022 were seen with clarithromycin (21%, 2021; 24%, 2022) and erythromycin (22%, 2021; 24%, 2022). Multidrug-resistant IPD continued to increase from 2018 to 2022 (6.7%-12.6%, p<0.05). Conclusion: The number of cases of IPD continued to decrease in 2021 in comparison to previous years, however, 2022 saw a return to pre-COVID-19 levels. Disease due to PCV13 serotypes 3, 4, 9V and 19F, as well as non-PCV13 serotypes 12F and 20, is increasing in prevalence. Surveillance of IPD to monitor changing serotype distribution and antimicrobial resistance is essential.
RESUMO
Background: Invasive group A streptococcal (iGAS, Streptococcus pyogenes) disease has been a nationally notifiable disease in Canada since 2000. This report summarizes the demographics, emm types, and antimicrobial resistance of iGAS isolates collected in Canada in 2021 and 2022. Methods: The Public Health Agency of Canada's National Microbiology Laboratory collaborates with provincial and territorial public health laboratories to conduct national surveillance of invasive S. pyogenes. Emm typing was performed using the Centers for Disease Control and Prevention emm sequencing protocol or extracted from whole-genome sequencing data. Antimicrobial susceptibilities were determined using Kirby-Bauer disk diffusion according to Clinical and Laboratory Standards Institute guidelines or predicted from whole-genome sequencing data based on the presence of resistance determinants. Results: Overall, the incidence of iGAS disease in Canada was 5.56 cases per 100,000 population in 2021, decreasing from the peak of 8.6 cases per 100,000 population in 2018. A total of 2,630 iGAS isolates were collected during 2022, representing an increase from 2021 (n=2,179). In particular, there was a large increase in isolates collected from October to December 2022. The most predominant emm type overall in 2021 and 2022 was emm49, at 21.5% (n=468) and 16.9% (n=444), respectively, representing a significant increase in prevalence since 2018 (p<0.0001). The former most prevalent type, emm1, increased from 0.5% (n=10) in 2021 to 4.8% (n=125) in 2022; similarly, emm12 increased from 1.0% (n=22) in 2021 to 5.8% (n=151) in 2022. These two types together accounted for almost 25% of isolates collected in late 2022 (October to December). Antimicrobial resistance rates in 2021 and 2022 included: 14.9%/14.1% erythromycin resistance, 4.8%/3.0% clindamycin resistance, and <1% chloramphenicol resistance. Conclusion: The increase of iGAS isolates collected in Canada is an important public health concern. Continued surveillance of iGAS is critical to monitor expanding emm types and antimicrobial resistance patterns.
RESUMO
Background: Invasive group A streptococcal (iGAS) disease (caused by Streptococcus pyogenes) has been a nationally notifiable disease in Canada since 2000. This report summarizes the demographics, emm types and antimicrobial resistance of iGAS infections in Canada in 2020. Methods: The Public Health Agency of Canada's National Microbiology Laboratory (Winnipeg, Manitoba) collaborates with provincial and territorial public health laboratories to conduct national surveillance of invasive S. pyogenes. Emm typing was performed on all isolates using the Centers for Disease Control and Prevention emm sequencing protocol. Antimicrobial susceptibilities were determined using Kirby-Bauer disk diffusion according to Clinical and Laboratory Standards Institute guidelines. Population-based iGAS disease incidence rates up to 2019 were obtained through the Canadian Notifiable Disease Surveillance System. Results: Overall, the incidence of iGAS disease in Canada has increased from 4.0 to 8.1 cases per 100,000 population from 2009 to 2019. The 2019 incidence represents a slight decrease from the 2018 rate of 8.6 cases per 100,000 population. A total of 2,867 invasive S. pyogenes isolates that were collected during 2020 are included in this report, representing a decrease from 2019 (n=3,194). The most common emm types in 2020 were emm49 (16.8%, n=483) and emm76 (15.0%, n=429), both increasing significantly in prevalence since 2016 (p<0.001). The former most prevalent type, emm1, decreased to 7.6% (n=217) in 2020 from 15.4% (n=325) in 2016. Antimicrobial resistance rates in 2020 included 11.5% resistance to erythromycin, 3.2% resistance to clindamycin and 1.6% nonsusceptibility to chloramphenicol. Conclusion: Though the number of collected invasive S. pyogenes isolates decreased slightly in 2020 in comparison to previous years, iGAS disease remains an important public health concern. The emm distribution in Canada has been subtly shifting over the past five years, away from common and well-known emm1 and towards emm49 and emm76. It is important to continue surveillance of S. pyogenes in Canada to monitor expanding replacement emm types, as well as outbreak clones and antimicrobial resistance.
RESUMO
Background: Invasive pneumococcal disease (IPD), which is caused by Streptococcus pneumoniae, has been a nationally notifiable disease in Canada since 2000. The use of conjugate vaccines has markedly decreased the incidence of IPD in Canada; however, the distribution of serotypes has shifted in favour of non-vaccine types. This report summarizes the demographics, serotypes and antimicrobial resistance of IPD infections in Canada in 2020. Methods: The Public Health Agency of Canada's National Microbiology Laboratory (Winnipeg, Manitoba) collaborates with provincial and territorial public health laboratories to conduct national surveillance of IPD. A total of 2,108 IPD isolates were reported in 2020. Serotyping was performed by Quellung reaction and antimicrobial susceptibilities were determined in collaboration with the University of Manitoba/Canadian Antimicrobial Resistance Alliance. Population-based IPD incidence rates were obtained through the Canadian Notifiable Disease Surveillance System. Results: Overall incidence of IPD in Canada decreased significantly from 11.5 (95% confidence interval [CI]: 10.1-13.1) to 6.0 (95% CI: 5.0-7.2), and from 10.0 (95% CI: 9.7-10.3) to 5.9 (95% CI: 5.7-6.2) cases per 100,000 from 2019 to 2020; in those younger than five years and those five years and older, respectively. The most common serotypes overall were 4 (11.2%, n=237), 3 (10.9%, n=229) and 8 (7.2%, n=151). From 2016 to 2020, serotypes with increasing trends (p<0.05) included 4 (6.4%-11.2%), 3 (9.5%-10.9%), 8 (5.2%-7.2%) and 12F (3.6%-5.7%). The overall prevalence of PCV13 serotypes increased over the same period (30.3%-34.9%, p<0.05). Antimicrobial resistance rates in 2020 included 23.0% clarithromycin and 9.9% penicillin (IV meningitis breakpoints). Multidrug-resistant IPD has significantly increased since 2016 (4.2%-9.5%, p<0.05). Conclusion: Though the incidence of IPD decreased in 2020 in comparison to previous years across all age groups, disease due to PCV13 serotypes 3 and 4, as well as non-PCV13 serotypes such as 8 and 12F, increased in prevalence. Continued surveillance of IPD is imperative to monitor shifts in serotype distribution and antimicrobial resistance.