What is a sexually transmitted infection (STI)?
Sexually transmitted infections (STIs) are diseases that can spread from person to person through any sexual contact. Many STIs do not have any obvious signs or symptoms at first. This is why it is very important that sexually active teens protect themselves and their partner(s) by using protection and getting tested regularly.
Why talk to your child about sex
It is important that your child receives information from a trusted, educated adult rather than friends or other sources that may not be reliable. Talking to your child about sex does not make them more likely to have sex. Having correct information can help your child make safe decisions and makes them less likely to engage in risky sexual activity. For more information about the importance of sex education, please see Sex education for children: Why parents should talk to their kids about sex.
When to talk to your child about STIs
By about 10 to 13 years old, most children understand what sex is and are ready to learn about STIs. For more information about what children should learn and can typically understand at various developmental stages, please see Sexuality: What children should learn and when.
How to talk to your child about STIs
It is best to have a continuing conversation about STIs rather than giving one big, and likely uncomfortable, talk once your child reaches adolescence. These conversations tend to be easier when they come out of a life experience. For example, you might discuss STIs during a TV show or movie that shows a romantic relationship, before your child gets the HPV vaccine or if your child asks questions about sex.
Your child should know how STIs are transmitted, how to protect themselves and their partner(s) from STIs and what to do if they suspect they have an STI. For more information about talking to your child about sex and STIs, please see Sex education for children: Eight tips for parents.
What are the different types of STIs?
- Chlamydia
- Gonorrhea
- Syphilis
- HPV
- Trichomoniasis
- Hepatitis B
- Hepatitis C
- Herpes
- Pubic lice
- Scabies
- HIV
Chlamydia
Chlamydia affects the cervix and urethra, and sometimes the rectum, throat and eyes. It is the most common bacterial STI and is more common in female-bodied people than male-bodied people.
Most people with chlamydia have no symptoms at all. Signs and symptoms of chlamydia may include:
- discharge from the penis or vagina
- vaginal bleeding after sex or between periods
- pain in the abdomen or lower back
- pain during sex
- itchy urethra
- pain or swelling in testicles
- pain or burning while urinating (peeing)
Chlamydia is diagnosed through a:
- urine sample or
- swab of cervix, urethra, vagina, rectum, nose, throat and/or eyes
Treatment for chlamydia is antibiotic pills.
A person who has had chlamydia should be retested six months after treatment.
Gonorrhea
Gonorrhea affects the cervix and urethra, and sometimes the rectum and throat. It is the second most common bacterial STI. You might sometimes hear it called ‘the clap’.
Signs and symptoms of gonorrhea may include:
- discharge from penis or vagina
- pain during sex
- pain in lower abdomen or pelvis
- vaginal bleeding after sex or between periods
- irregular periods
- pain or swelling in testicles
- pain or burning while urinating
Some people may have no symptoms.
Gonorrhea is diagnosed through a:
- urine sample or
- swab of the infected area (penis, vagina, cervix, anus, throat and/or eye)
Gonorrhea is treated with antibiotic pills and muscular injection.
A person who has had gonorrhea may be instructed by their health-care provider to be re-tested two to three weeks after treatment to ensure the infection is gone. All individuals who have been treated for gonorrhea should be retested six months after treatment.
Syphilis
Syphilis is caused by bacteria. Rates of cases have been increasing in Canada.
Syphilis has four stages of symptoms:
- Primary – a painless sore at the affected area.
- Secondary – flu-like symptoms and rash developing three weeks to six months after infection.
- Latent – syphilis is untreated and generally has no symptoms; this phase can continue for years.
- Tertiary – 10–30 years after infection; damage to organs.
Syphilis is diagnosed through a:
- swab of affected area (primary syphilis only)
- blood test
Syphilis is treated with penicillin or other antibiotics. Early treatment is important as damage caused by syphilis cannot be reversed.
HPV and genital warts
Human papillomavirus (HPV) is the most common STI. The highest rates of HPV are in teens and young adults aged 15–24 years old.
Some types of HPV can cause genital warts, and others can cause cancer if left untreated.
A vaccine is available to prevent HPV. Please see Human papillomavirus (HPV) vaccine for more information.
Some people may not have any signs or symptoms at all, while others might have the following:
- warts that look like tiny bumps on the vagina, anus, cervix or inside of the thigh; these may be small or hard to see
- pain or bleeding
HPV is diagnosed through a:
- visual exam
- pap test (typically only for those age 25 or older, but guidelines vary by province. In some places, a pap test may be recommended as early as age 21)
Treatment for HPV includes watching the warts to see if they go away or wart removal by a health-care professional (over-the-counter wart medicine should never be used on genital warts unless prescribed by a health-care professional).
Trichomoniasis
Trichomoniasis is a common infection affecting the vulva, vagina, cervix, urethra, bladder and penis.
Signs and symptoms of trichomoniasis may include:
- discharge or odor from the vagina or penis
- pain or burning while peeing
- pain during sex
- itchiness
It is diagnosed through a swab of the affected area.
Treatment for trichomoniasis is antibiotic pills.
Hepatitis B
Hepatitis B is a virus that affects the liver.
A vaccine is available to prevent hepatitis B.
Most people do not have signs of hepatitis B. Up to eight weeks after exposure, they may have flu-like symptoms.
Hepatitis B is diagnosed with a blood test.
There is no cure for hepatitis B, but most people recover and have no symptoms after six months.
Hepatitis C
Hepatitis C is a virus that affects the liver.
Acute symptoms of hepatitis C may include:
- flu-like symptoms
- decreased appetite, weight loss
- jaundice
- rash
- dark urine or clay-coloured stool
Chronic symptoms of hepatitis C may include:
- jaundice
- swelling of the abdomen (belly)
- blood in stool (poo) and vomit
- interrupted sleep
- depression
- weight loss
- itchy skin
- brain disease
Hepatitis C is diagnosed with a blood test.
A combination of medications is used to treat the hepatitis C infection. Treatment also includes preventing liver damage.
Herpes
There are two types of herpes:
- HSV-1 more commonly causes oral infection (cold sores, fever blisters around the mouth)
- HSV-2 more commonly causes genital herpes with lesions/sores around the vulva, vagina, cervix, anus and penis
Both HSV-1 and HSV-2 can infect both the mouth and the genitals. They can both be spread by kissing, touching, oral sex and unprotected vaginal or anal sex.
Symptoms of a first infection may include:
- flu-like symptoms
- cold sore or fever blister around the nose, lips or in the mouth
- pain while peeing
- genital pain
- genital blisters
- genital ulcers
Symptoms of a recurrent infection (an infection that comes back) include:
- tingling, itching or burning
- sores inside the mouth or on the lips, vulva, vagina or penis
Herpes is diagnosed through a swab of a lesion/sore.
Medication is used to decrease the length and severity of a herpes outbreak. There is no cure for herpes.
Pubic lice
Pubic lice are small insects that nest in pubic hair. They are sometimes called ‘crabs’ because of their appearance.
Pubic lice can also be found in the eyebrows, armpit hair, beards and mustaches.
The main signs and symptoms of pubic lice are itching, redness or irritation at the affected area.
They are diagnosed through a physical exam of the infected area by a health-care professional.
Pubic lice are treated with medicated creams, lotions or shampoos to apply to the affected area.
Scabies
Scabies are mites that burrow under the skin to lay eggs.
Signs and symptoms of scabies may include:
- rash or bumps, particularly in a line
- itching
Scabies is diagnosed through:
- a physical exam of the infected area by a health-care professional
- scraping of the rash to look for mites, fecal matter of mites or mite eggs under a microscope
Scabies are treated with scabicide creams or lotions to apply to the affected area.
HIV
Human immunodeficiency virus (HIV) is a virus that attacks the immune system. In some cases, it can develop into AIDS.
Signs and symptoms of HIV may include:
- mild flu-like symptoms that develop two to four weeks after exposure then disappear
After several years (usually after at least 10 years), symptoms may include:
- flu-like symptoms
- enlarged lymph nodes
- shortness of breath or dry cough
- vision loss
- lesions on skin
- anemia
- severe shingles or oral or genital ulcers
In very rare cases, some people do not have any symptoms (chronic asymptomatic HIV).
HIV is diagnosed through blood work.
Antiretroviral therapy is used to slow the progression of HIV.
How to prevent STIs
The best ways to prevent STIs are to:
- use protection such as condoms
- discuss STIs and safe sex with partner(s) in order to protect each other
- ask a health-care provider about getting vaccinated against hepatitis B and human papilloma virus (HPV)
- get tested regularly for STIs
If your teen has an STI, they must not have sex until the infection is gone, and their health-care provider says it is OK. If the STI has no cure (such as herpes or HIV) it is important that your teen always uses protection.
What if my teen thinks they have an STI?
If your teen thinks they might have an STI, they should contact their health-care provider. Or they can visit the Action Canada for Sexual Health and Rights website to find a sexual health clinic near them.