This brief report provides an overview of case reports and trends in the three nationally reportable bacterial sexually transmitted infections (STIs): chlamydia, gonorrhea, and infectious syphilis between January 1, 1998 and December 31, 2007. Although only the past ten years of data are presented to reflect recent STI trends, it should be noted that 1997 marked the beginning of the surge in STI rates in Canada. The surveillance data presented in this report are drawn from case reports to the Public Health Agency of Canada (PHAC) from provinces and territories.

This brief report consists of four sections. Sections one to three correspond to the three nationally reportable bacterial STIs. Each section summarizes major findings and trends in the respective infection, and the embedded tables and figures are updated from those in earlier publications of these data. The fourth section features an international comparison of the current state of STIs between Canada and other western countries (United States, Australia, and the United Kingdom). Technical notes and explanatory details specific to provincial or territorial surveillance data are presented at the end of this report.

The publication of this brief report would not have been possible without the submission of data from all provinces and territories. Their ongoing contribution to national STI surveillance is gratefully acknowledged.

Any comments and suggestions that would improve the usefulness of future publications are appreciated and should be sent to the attention of the Community Acquired Infections Division at ph-sp-info@phac-aspc.gc.ca.

Table of Contents

• Acknowledgements
• Executive Summary
• Chlamydia (Chlamydia trachomatis)
• Gonorrhea (Neisseria gonorrhoeae)
• Syphilis (Treponema pallidum)
• International Comparison
  • Chlamydia
  • Gonorrhea
  • Syphilis
• Technical Notes
• References

Acknowledgements

The preparation of this brief report would not have been possible without the contributions of the provincial and territorial ministries of health. We gratefully acknowledge them for the surveillance data provided to the Public Health Agency of Canada and their expert contributions to the surveillance of nationally notifiable sexually transmitted infections.

Production of this brief report and previous surveillance reports would not have been possible without the valuable inputs of Dr. Tom Wong, Director, Community Acquired Infections Division, Centre for Communicable Diseases and Infection Control,  Public Health Agency of Canada.

Many others contributed to the development and publication of this report:

• Local, provincial, and territorial public health units across the country with their continued commitment to collecting the data that form the basis of national surveillance;
• The Notifiable Disease Section, Surveillance and Risk Assessment Division, Public Health Agency of Canada, which is responsible for maintaining the Canadian Notifiable Disease Surveillance System from which counts of bacterial STIs are derived;
• The Federal Field Surveillance Officers who assist with data quality improvements and provide ongoing support to the Community Acquired Infections Division;
• The Communications Directorate, Marketing, Creative Services and E-Comms Division, Public Health Agency of Canada

Executive Summary

Sexually transmitted infections (STIs) continue to be a significant and increasing public health concern in Canada.  Reported rates of chlamydia, gonorrhea and syphilis have been rising since 1997.  This report outlines the trends in these three nationally notifiable STIs from 1998 to 2007, providing an overview of the descriptive epidemiology of these infections in Canada.

Chlamydia continues to be the most commonly reported STI in Canada.  Reported rates of chlamydia infections have increased by 73.6% from 1998 to 2007. A steady increase in reported rates has been observed in both genders and across all age groups, with the highest relative increase among males. However, females remain disproportionately affected by chlamydia infection.  In 2007, the reported rate among women was almost twice as high as that of their male counterparts, and 82.8% of reports among females were for those under the age of 30. The reported rate among males over the age of 60 was three times as high as their female counterparts corresponding to a reduction in the female to male ratio of reported rates among the older population. Geographic variation was observed with the highest chlamydia rates reported in Nunavut, the Northwest Territories and Yukon.

The overall reported rate of gonorrhea increased by 124.2% between 1998 and 2007. The majority of reported cases were in those under 30 years of age. Females between the ages of 15 to 24 and males between the ages of 20 to 24 accounted for the highest reported rates of gonorrhea. The older male population, particularly those over the age of 60, experienced a dramatic rise in the rate of reported cases since 1998, although reported rates remain low in this group compared to other age groups. Like chlamydia, the distribution of reported cases of gonorrhea varies geographically across Canada. The highest reported rates occurred in the Northwest Territories and Nunavut, followed by Manitoba and Saskatchewan.

The overall reported rate of infectious syphilis increased by 516.7% between 1998 and 2007.  Reported rates of infection were highest among males aged 30 to 39; among females, highest rates were reported among those 25 to 29 years old.  During this time period, outbreaks were reported in Vancouver, Edmonton, Calgary, Winnipeg, Toronto, Ottawa, Montreal, and the Yukon among men who have sex with men and among heterosexual populations.

Reported Cases and Rates of Chlamydia, Gonorrhea, and Syphilis, 1998 and 2007

	Chlamydia		Gonorrhea		Syphilis
	Cases	Rates	Cases	Rates	Cases	Rates
1998	39034	129.0	4868	16.1	177	0.6
2007	73770	224.0	11873	36.1	1206	3.7

 

Comparisons of reported STI rates to those of other western regions such as the United States, Australia, and the United Kingdom demonstrate that the observed increase in bacterial STIs is not unique to Canada, along with other similarities in trends. In all four countries, chlamydia is the most commonly reported STI and affects predominantly younger age groups, especially females. Gonorrhea rates in each country are highest in males aged 20 to 24. Across countries, males have the highest rates of infectious syphilis, reflecting the recent occurrence of outbreaks among men who have sex with men (MSM).

Brief Report on Sexually Transmitted Infections in Canada: 2007

Chlamydia, gonorrhea, and syphilis are sexually transmitted infections of public health significance included on the list of nationally notifiable diseases in Canada. Resultant surveillance data are analyzed and summarized periodically. Several observations for 2007 are noteworthy.

How to Reach Us

For more information, copies of this report or other related reports, please contact:

STI and HCV Surveillance and Epidemiology Section
Community Acquired Infections Division
Centre for Communicable Diseases and Infection Control
Public Health Agency of Canada
100 Eglantine Driveway, Health Canada Building #6
A.L. 0603B, Tunney’s Pasture
Ottawa, Ontario  K1A 0K9

Email: ph-sp-info@phac-aspc.gc.ca

This report was prepared by the following individuals in the STI and HCV Surveillance and Epidemiology Section:

Gayatri Jayaraman, PhD, MPH 
Manager

Stephanie Totten, MSc
Senior Epidemiologist (Acting)

Maureen Perrin, MSc (C), ITPM
Senior Epidemiologist

Lily Fang, MHSc
Epidemiologist

Carmen Yue, MHSc (C)
Student Epidemiologist

Olivia Remes
Student