Sexually transmitted infections (STIs)
Transmission
Sexually transmitted infections (STIs) are infections that are transmitted by sexual contact:
- Oral sex (contact between the mouth and the penis, vulva, vagina, or anus)
- Vaginal intercourse (penetration of the penis into the vagina)
- Anal intercourse (penetration of the penis into the anus)
- Contact between the partners' genitals
- Sharing of sex toys
STIs can be transmitted even if the infected person is not experiencing symptoms. Furthermore, some STIs can be transmitted through the blood, such as HIV and hepatitis B. A baby can also contract an STI during childbirth if the mother is infected. However, contrary to many common myths, you cannot get STIs from toilet seats, towels, or insect bites.
Prevention and treatment
Below are some of the ways you can reduce the risk of spreading an STI:
- Use a condom during all sexual activities
- Use a dental dam (thin sheet of latex or cut condom) during oral or genital sexual contact
- Do not have sexual intercourse with someone who has STI symptoms
- Limit your number of sexual partners
- Do not use unsterilized injection equipment
- Do not get a tattoo or piercing with a used needle
The condom is the only contraceptive that's effective in preventing STI transmission. Other contraceptives (e.g., oral contraceptives and IUDs) do not protect against STIs.
Some STIs can be treated with antibiotics. Others, however, cannot be cured, such as herpes and HIV. When treatment is available, it's important to follow it as recommended, even if your symptoms clear up before the end of the specified treatment period. Treatment helps stop the transmission of STIs and prevent complications.
When should I see a health care professional?
Many STIs have no signs or symptoms. It's therefore important to always use protection during sexual intercourse and to see your health care professional for regular STI testing.
Getting an STI test is recommended in the following situations:
- You recently had unprotected sex
- You shared injection equipment or got a tattoo or piercing with a used needle
- You had sexual intercourse with
- a new partner,
- several partners, or
- someone with an STI.
- You have STI symptoms
- You're pregnant or want to become pregnant
The main sexually transmitted infections
| STI | Incubation period* | Signs and symptoms | Comments |
|---|---|---|---|
| Chlamydia | From 5-10 days to several weeks | Often without symptoms. Vaginal or penile discharge, pain when urinating. Women: Pain during sex, vaginal bleeding after sex or between periods. Men: Pain in the testicles, itching inside the penis. Rectal infection: Pain in the rectum, discharge, bleeding. Throat infection: Pain, cough, swollen lymph nodes, fever. Eye infection: Redness, itching, discharge. | Chlamydia is caused by the bacteria Chlamydia trachomatis. It is the most common sexually transmitted infection in Canada. Testing involves analyzing a swab of the affected area or taking a urine sample. If left untreated, the infection can lead to complications:
The infection is treated with antibiotics. |
| Condyloma | Between 3 weeks and several months | Warts, which may look like cauliflower or be flat. They may be itchy, bleed, or have discharge. Women: On the thighs, vulva, vagina, anus, rectum, or cervix. Men: On the thighs, penis, scrotum, anus, or rectum. | Condyloma is caused by the human papillomavirus (HPV), which is also sometimes associated with cervical cancer. The Pap smear and HPV DNA test can detect cervical cancer. There is no equivalent test for men, but they can be examined for genital warts as well as any signs of cancer of the penis, anus, mouth, or throat. There are treatments for genital warts, but they do not cure the infection itself. In most cases, the person's immune system will clear the virus within 2 years. There is a vaccine that protects against HPV infection. |
| Gonorrhea | 2-7 days | Often without symptoms. Purulent discharge from the vagina or penis, pain when urinating. Women: Pain during sex, vaginal bleeding after sex or between periods. Pregnant women: Possible transmission to the baby during childbirth, causing a serious eye infection. Men: Pain in the testicles. Rectal infection: Pain in the rectum, discharge, bleeding, itching. Throat infection: Pain | Gonorrhea is caused by the bacteria Neisseria gonorrhoeae. Testing involves analyzing a swab of the affected area or taking a urine sample. If left untreated, the infection can lead to complications:
The infection is treated with antibiotics. |
| Hepatitis B | 1-6 months | Often without symptoms. Fever, nausea and vomiting, fatigue, abdominal discomfort, yellowish discolouration of the eyes and skin. | Hepatitis B is caused by the hepatitis B virus. Testing involves analyzing a blood sample. The body is often able to eliminate the virus and develop lifelong immunity. However, a minority of those affected will remain infected throughout their lives. Hepatitis B can develop into chronic hepatitis, cirrhosis (liver disease), or liver cancer. There is a vaccine that protects against hepatitis B. |
| Genital herpes | Within 12 days | Often with mild or no symptoms. Itching, tingling, or burning sensation around the genitals. Clusters of fluid-filled blisters on the genitals, thighs, or buttocks that burst and form small ulcers. Painful and swollen lymph nodes in the groin area. Fever, body aches, and headaches. | Genital herpes is caused by the Herpes simplex virus type 1 or type 2. People with the virus remain infected throughout their lives. They may have recurring outbreaks of genital herpes. Symptoms are more severe during the first episode and become milder over time. There is no cure for genital herpes, but medications can relieve the pain and decrease the frequency of episodes. |
| Lymphogranuloma venereum (LGV) | 3-30 days | Some people have no symptoms. First stage: Painless lesions in the vagina, penis, rectum, cervix, or mouth. Second stage: Swollen and tender lymph nodes in the groin or neck, fever, muscle and joint pain, fatigue, chills, purulent discharge from the anus. Symptoms develop 2-6 weeks after the primary lesions have healed. Third stage: Serious complications affecting the genital area that develop 1-20 years after contact with the bacteria. | LGV is caused by a bacteria in the Chlamydia trachomatis family. If treated during the first or second stage, the infection can be completely cured. Complications that develop in the third stage can cause permanent damage. Testing involves analyzing a swab of the affected area. The infection is treated with antibiotics. |
| Syphilis | 3-90 days | Some people have no symptoms. First stage: Painless ulcers in the genitals, anus, or throat. Second stage: Flu-like symptoms (fever, headache, fatigue, muscle pain, swollen lymph nodes), rashes on the hands, feet, or elsewhere on the body. Symptoms appear up to 6 months after contact with the bacteria. Third stage: Complications affecting the heart, brain, bones, or liver that develop 5-30 years after contact with the bacteria. | Syphilis is caused by the bacteria Treponema pallidum. If treated during the first or second stage, the infection can be completely cured. Complications that develop in the third stage can cause permanent damage. In pregnant women, syphilis can be passed on to the baby and cause birth defects, or even death. Testing involves analyzing a swab of the affected area or taking a urine sample. The infection is treated with antibiotics. |
| Trichomoniasis | 4-28 days | Often without symptoms. Women: Vaginal itching, whitish foamy vaginal discharge, unpleasant smell, pain during sex or when urinating. Men: Usually without symptoms. Sometimes penile discharge and pain when urinating. | Trichomoniasis is caused by a parasite called Trichomonas vaginalis. In pregnant women, it can increase the risk of complications during pregnancy or childbirth. Testing involves analyzing a swab of the affected area or performing a physical examination. The infection is treated with antibiotics. |