Prevalence of Chlamydia trachomatis and herpes simplex virus type 2: Results from the 2009 to 2011 Canadian Health Measures Survey.

BACKGROUND

Chlamydia, caused by Chlamydia trachomatis, and genital herpes, caused by simplex virus type 2 (HSV-2), are common sexually transmitted infections. Their prevalence has been estimated in selected populations, but overall prevalence in Canada is not known.

DATA AND METHODS

Data are from the 2009 to 2011 Canadian Health Measures Survey. Socio-demographic, health and lifestyle information was obtained via a household questionnaire; blood and urine collected at a mobile examination centre were used to identify the presence of Chlamydia trachomatis and HSV-2 among 14- to 59-year-olds.

RESULTS

An estimated 13.6% of Canadians (2.9 million) tested positive for HSV-2, and another 0.7% (158,000), for chlamydia. HSV-2 affects higher percentages of women than men, and individuals aged 35 to 59 versus 15 to 34. No significant differences in HSV-2 prevalence were detected by marital status, household income, education, or racial background. Nearly all individuals with laboratory-confirmed chlamydia or HSV-2 were unaware that they were infected.

INTERPRETATION

This study is the first in Canada to report laboratory-confirmed prevalence of chlamydia and HSV-2 using a nationally representative sample. Results suggest that most infected people are unaware of their status.