STI Basics
Sexually transmitted infections (STIs) are caused by microorganisms that can be passed from person to person through sexual contact (vaginal, anal or oral sex). The consistent and correct use of condoms can substantially reduce, but not eliminate, the risk of acquiring or transmitting these infections.
Here is some basic information on the most common STIs in Canada.
Bacterial STIs
New diagnoses of STIs are on the rise in Canada, as in other high-income countries. In Canada, there are three reportable bacterial STIs: chlamydia, gonorrhea and infectious syphilis.
Chlamydia
Chlamydia is most easily passed on during sex without a condom. It can infect the genitals, rectum and throat. The infection can be cured with antibiotics, and there are ways to lower the chance of getting or passing on chlamydia, such as using a condom when having sex.
What are the symptoms?
Many people with chlamydia have no symptoms, so they don’t know they have an infection. When symptoms do occur, they usually take 2 to 3 weeks to appear but it can take as long as six weeks. Common symptoms vary depending on where the infection is:
- Infections of the genitals can cause an unusual fluid (or discharge) to come out of the vagina or the penis, and pain when urinating (peeing).
- Rectal infections can cause discharge or bleeding from the anus and pain in the anus.
- Throat or mouth infections can cause a sore throat.
If it is not treated, chlamydia may lead to infertility, abdominal pain or pregnancy complications.
How is it treated?
Chlamydia can be cured with a single dose or a short course of antibiotics. If someone is given a single dose to treat the infection, they should wait for seven days after taking it before having sex again. If someone is given pills to take for seven days, they should wait until they have taken all the pills before having sex again. If the person has a regular partner or partners, they should also be treated before having sex with them again.
Once someone is cured, they cannot pass on chlamydia to their sex partners. But they can be infected again. Being treated for chlamydia does not protect someone from getting chlamydia in the future.
Gonorrhea
Gonorrhea is most easily passed on during sex without a condom. It can infect the genitals, rectum, mouth and throat. The infection can be cured with antibiotics, and there are ways to lower the chance of getting or passing on gonorrhea, such as using a condom when having sex.
What are the symptoms?
Many people with gonorrhea have no symptoms, so they don’t know they have an infection. When symptoms do occur, they can take 2 to 7 days to appear. Common symptoms vary depending on where the infection is:
- Infections of the genitals can cause an unusual fluid (or discharge) to come out of the vagina or penis, pain when urinating (peeing), vaginal bleeding, bleeding between periods, painful vaginal sex, swelling or pain in the testicles or pain in the abdomen.
- Rectal infections can cause anal itching, discharge from the anus, painful bowel movements or the feeling of needing to have a bowel movement.
- Throat or mouth infections can cause a sore throat.
If it is not treated, gonorrhea may lead to infertility, abdominal pain or pregnancy complications.
How is it treated?
Gonorrhea can be cured with a single dose of oral and injected antibiotics, though treatment can vary in different regions. After someone has been treated, another test may be performed to ensure that they no longer have gonorrhea. People should wait 7 days after treatment is finished to have sex again.
Once someone is cured, they cannot pass on gonorrhea to their sex partners. But people can be infected again. Being treated for gonorrhea does not protect someone from getting gonorrhea in the future.
Syphilis
Syphilis is most easily passed on by contact with a syphilis sore during sex. Early on, it can cause sores on or in the genitals, anus or mouth. It can also be passed from a mother to her baby when pregnant. The infection can be cured with a single dose of penicillin, and there are ways to lower the chance of getting or passing on syphilis, such as using a condom when having sex.
What are the symptoms?
Many people with syphilis have no symptoms, so they don’t know they have syphilis. When symptoms of initial infection do occur, they usually take 2 to 3 weeks to appear. Untreated syphilis progresses through stages. Common symptoms vary depending on the stage.
Primary syphilis: A painless sore appears at the site of infection but will heal in 3 to 6 weeks with or without treatment. Because many people do not see the sore, they are not aware of the infection.
Secondary syphilis: A non-itchy rash may appear, most commonly on the chest, stomach, genitals, palms of the hands and soles of the feet, 2 weeks to 3 months after infection, and it may last for 2 to 6 weeks. Additional sores may also appear. Fever, headache, muscle ache, lack of appetite and fatigue can occur.
Late syphilis (tertiary stage): Without treatment, secondary syphilis turns into late syphilis (also called latent or tertiary syphilis). This can develop from 2 to 30 years after infection. Initially, the infection may show no signs but the syphilis germs are injuring tissues. Eventually, the injury to important organs, such as the eyes, skin, bones, liver, kidneys and heart, can cause symptoms.
Neurosyphilis: Syphilis can affect the brain. This is called neurosyphilis. In cases where the brain is affected, changes in personality can occur, as can problems with thinking clearly and memory. Neurosyphilis can occur at any stage of syphilis.
Syphilis passed from mother to baby (congenital syphilis)
When a woman is infected with syphilis while pregnant, the disease can cause miscarriage, stillbirth or the death of a newborn. Most babies born with syphilis have no symptoms although some may have a rash. If the syphilis is not treated, babies can have developmental problems, seizures and other serious health issues.
How is it treated?
Syphilis can be cured with a single dose of penicillin if diagnosed within the first year of infection. People with HIV and those infected for longer than one year may require more medication for a longer period.
After treatment is completed, a person should wait 7 days before having sex again. If someone has a lesion or rash, they should wait until the symptoms disappear before having sex again.
Once someone is cured, they cannot pass on syphilis to their sex partners. But they can be infected again. Being treated for syphilis does not protect someone from getting syphilis in the future.
Viral STIs
Human papillomavirus
Human papillomavirus (HPV) is most easily passed on during sexual contact. Most HPV infections will go away without treatment, but some types of the virus can cause genital or anal warts or lead to cancer. HPV cannot be cured by medication, but a vaccine is available to prevent some types of HPV. Consistent condom use can reduce but not eliminate the risk of getting or passing on HPV during sex.
There are many different types of HPV, and they can infect different parts of the body. Most types of HPV do not cause any health problems, and most HPV infections clear up on their own without treatment. However, infection with some types of HPV can lead to genital or anal warts, while some others can lead to cancer of the cervix, anus, penis or throat.
What are the symptoms?
Many people with HPV have no symptoms so they don’t know they have an infection. Genital or anal warts are a symptom of HPV infections with certain types of the virus. These warts are painless bumps on the genitals, anus or buttocks. The warts can be different sizes and shapes. It can take a long time (months or years) for symptoms to develop and be noticed.
How is it treated?
HPV cannot be cured with medication. A doctor can treat warts, but the warts may come back and the person will still have HPV until the infection goes away. As long as the person has HPV, they could pass it on to others.
Any tests that indicate the possibility of cancer or precancer need follow-up by a doctor.
Genital herpes
Genital herpes is caused by the herpes simplex virus and is most easily passed on by contact with infected skin during sex. It can cause blisters on the genitals, anus, rectum, and/or lips and mouth. Treatment can reduce symptoms, but the infection cannot be cured by medication. There are ways to lower the chance of getting or passing on genital herpes, such as using a condom each time you have sex.
What are the symptoms?
Many people with genital herpes have no symptoms or they mistake the symptoms for another condition, so they don’t know they have an infection. When symptoms do occur, they can take up to 2 to 12 days to appear. Common symptoms can include:
- blisters (lesions), individually or in clusters, anywhere in the area of the genitals or anus; these blisters crust over and heal within one to two weeks
- itchy, tingly, burning or painful skin in infected areas
- pain in the legs or buttocks
- swollen lymph nodes in the groin
- watery discharge from the vagina
- fever, headache, muscle ache
- fatigue
How is it treated?
Genital herpes cannot be cured with medication. However, if someone has genital herpes, antiviral medications can help prevent outbreaks or reduce symptoms during an outbreak. For these medicines to work, it is important they are taken exactly as directed.
During an outbreak, people can take over-the-counter pain medication, apply ice packs to the lesions, take warm baths with salt or baking soda and wear loose-fitting cotton underwear to help reduce pain or irritation.
Hepatitis A
Hepatitis A is caused by the hepatitis A virus and can be passed on when feces from an infected person gets into the mouth of another person. The virus infects the liver. There is a vaccine for hepatitis A but there is no treatment for hepatitis A. Most people recover from the infection on their own. There are ways to lower the chance of getting or passing on hepatitis A, such as getting vaccinated, practising good hygiene and using a barrier for any kind of anal sex.
What are the symptoms?
Most adults with hepatitis A have some symptoms. Symptoms can take 2 to 6 weeks to appear. Common symptoms include:
- fatigue
- loss of appetite
- nausea or abdominal pain
- fever
- yellowing of the skin or eyes (jaundice)
- light-coloured stool
- dark urine (pee)
Most adults will recover from the infection on their own within 2 months.
How is it treated?
Hepatitis A cannot be cured with medication. Most adults will recover from the infection on their own. Once the infection clears, people have immunity from getting hepatitis A again.
Related links:
Sexually transmitted infections
HPV, cervical dysplasia and cervical cancer
HPV, anal dysplasia and anal cancer