Topic Overview

Sexually transmitted infections (STIs) are some of the most widespread diseases in the world. STIs affect both men and women, and almost half of all STIs occur in people younger than 25. Exposure to an STI can occur any time you have sexual contact that involves the genitals, the mouth (oral), or the rectum (anal). Exposure is more likely if you have more than one sex partner or do not use condoms. Some STIs can be passed by non-sexual contact, such as during the delivery of a baby or during breastfeeding.

Although recommendations for screening vary with the specific STI, screening is generally recommended for those at high risk. Your risk for an STI increases if you:

• Have unprotected intercourse without male or female condom use, except in a long-term, single-partner (monogamous) relationship.
• Have unprotected mouth-to-genital contact, except in a long-term monogamous relationship.
• Have early sexual activity, especially before age 18.
• Have multiple sex partners.
• Have a high-risk partner (one who has or had multiple sex partners or other risk factors).
• Have anal sex or a partner who does, except in a long-term, single-partner (monogamous) relationship.
• Have sex with a partner who injects or has ever injected drugs.
• Exchange of sex (sex work) for drugs or money.

The Public Health Agency of Canada (PHAC) strongly recommends that all pregnant women be screened for STIs (such as syphilis and HIV) because of the risks of being pregnant while infected or having a child born with certain STIs. Screening should be done:^{footnote 1}

• As early in the pregnancy as possible or at the first prenatal visit.
• During the third trimester and again at delivery for pregnant women who have an increased risk of getting an STI.

Early treatment with highly active antiretroviral therapy (HAART) can reduce the risk of passing HIV to your baby.