Background In Canada, there are three nationally notifiable sexually transmitted infections (STI): chlamydia, gonorrhoea, and infectious syphilis (includes primary, secondary, and early latent infections). Surveillance of these infections involves local, provincial/territorial and federal levels of government. This analysis examines trends in the rates of reported cases of these STIs from 2002 to 2011.

Methods Reportable STI data are compiled at the national level to examine trends over time by age, sex, and geographical distribution of cases across the country. Data for 2011 are preliminary; therefore, sex-specific rates are not available at this time.

Results Preliminary reported rates of chlamydia and gonorrhoea in 2011 were 290.2 and 33.1 per 100,000, respectively. Rates increased 62% for chlamydia and 41% for gonorrhoea from 2002. Youth and younger adults have the highest rates of these infections, particularly in females. However, in older adults (40+ for chlamydia and 25+ for gonorrhoea), males have higher rates.

The rate of reported cases of infectious syphilis in 2011 was 5.1 per 100,000 (an increase of 240% from 2002). Increases have been driven almost entirely by cases reported among men; in 2010, it was reported in nearly 10 times as many males as females. Males aged 20 to 59 have high rates of reported infectious syphilis.

Conclusion While the implementation of nucleic acid amplification testing beginning in 1997 likely contributed to the initial rise in STI rates at that time, it is improbable that its use has continued to affect rates to such an extent. The effects of erectile dysfunction and club drugs, sexual health education, and sexual practises on national STI rates have yet to be confirmed; more research is needed into these potential contributors. National efforts to combat the rising rates of STI include educational and clinical guidelines to prevent and control their spread.