A service provided by the BC Centre for Disease Control



All About Sexually Transmitted Infections

Sexually transmitted infections (STIs) are caused by an organism (bacteria, virus, or parasite) that can be passed from one person to another during sex or intimate contact. STIs are very common and can be treated or managed.

STI Basics

Most STIs are passed between sexual partners through unprotected oral, genital, or anal sex. Learn the basics of STI prevention, symptoms, testing, and treatment or management.

Learn the basics


STIs & Conditions

Specific information about different STIs and associated conditions, including how they are passed, symptoms, prevention, testing, treatment and more.

Browse all STIs


Patient Resources

Downloadable resources on a variety of STI related topics developed by the BC Centre for Disease Control.

Browse all resources


Frequently Asked Questions

Can you have sex with a condom within the 7 days you while taking antibiotic treatment for the chlamydia or gonorrhea?

The short answer is no.

To be on the safe side we recommend that you do not have any sex until:

  • one week after your 1-day treatment; or your 7-day treatment is complete;


  • your sex partner(s) have also been treated, even if their test results are negative;
  • your symptoms are now gone.

While condoms reduce the chance of passing chlamydia and gonorrhea, there is still a possibility of passing them even when a condom is used.

Even after you start taking treatment for chlamydia and/or gonorrhea, you can still pass them within the first 7 days. It takes 7 days for the medication to treat these infections. Only after 7 days is the chance of passing these infections gone.

Even if your partner is taking treatment at the same time as you, we still recommend you do not have sex until after 7 days. The treatment won’t work if someone is re-exposed to chlamydia and/or gonorrhea within those 7 days.

If you cannot avoid having sex for 7 days, then using a condom will help lower the chance of passing the STI to your partners and/or getting the infection again, but there is no guarantee.

It is also important to avoid sex when you have chlamydia and/or gonorrhea because they can increase your chance of getting HIV. Once the chlamydia and/or gonorrhea is gone, the HIV risk returns to normal.

If you did have sex during the 7 days, then we recommend that you talk to your health care provider, or return to the clinic where you got the treatment. In some situations, they will recommend that you and your partner(s) be re-treated, or suggest that you come back for a follow-up test in 4 weeks to check if the infection is gone.

Have a look at our web pages on ‘Chlamydia’ and ‘Gonorrhea’ for additional information.


How long after sex, does it take for STI symptoms to develop?

Firstly, it is important to remember that often STIs are asymptomatic, meaning you may be infected but show no symptoms.

Whether or not you will develop symptoms also  depends on the sexually transmitted infection (STI).

The incubation period is the time it takes from when you first get an STI and when signs and symptoms would likely appear.

Every STI has a different incubation period. Have a look at our ‘STI at a Glance’ chart. It provides information on what common symptoms to look for, incubation and window periods (when test results are accurate).

Because many people do not develop symptoms, this is why we recommend, that even if people do not have symptoms, they test for STI regularly.

Have a look at our ‘Got symptoms’ page for more information.


Are flavoured condoms safe to use for sex? Can they increase a person’s chance of getting STIs or lead to a vaginal yeast infection?

Flavoured condoms are safe to use with oral sex. They are popular as some people find they taste better than regular condoms, and they come in a variety of flavours.

The safety of using flavoured condoms of penetrative sex (like vaginal/internal genital or anal/rectal sex) is not well studied.

People can be sensitive to different condom materials and lubricants. With flavoured condoms, there are extra ingredients added for the flavour; these ingredients can cause vaginal/internal genital or anal/rectal irritation. Whenever the vagina/internal genitals or anus/rectum are irritated, it is easier to get an STI.

In addition, these ingredients may also irritate the vagina/internal genitals, causing the natural vaginal/internal genital flora to be imbalanced, which can lead to yeast infections or bacterial vaginosis.

Regardless of which type of condom you use, it is important to use  a new condom every time you have sex, with each new partner, and when switching from anal/rectal to oral or vaginal/internal genital sex.

If you used a flavoured condom for vaginal/internal genital or anal/rectal sex and noticed no irritation, there would be no increased risk of STIs and the condom would provide good protection.

For more information about condoms, lubricant, dental dams and other barriers, have a look at our ‘Protection’.


Which STIs can I get from oral sex?

The most common STIs passed with condomless oral sex are gonorrhea, syphilis, chlamydia and human papillomavirus (HPV).

Herpes can be passed from the mouth or genitals to a partner’s mouth or genitals.

The chances of getting HIV is considered low. If you had a throat infection, bleeding gums or sores in your mouth, your chances of getting HIV may increase.

Have a look at our ‘Oral sex’ and ‘My chances’ pages for more information.


If my partner is HIV positive, what can I do to protect myself from getting it?

Getting tested for STIs (including HIV) regularly, even if you do not have any symptoms. Having an STI can increase your chances of getting HIV.

Condoms are an excellent way to protect you from HIV. If a condom is used properly, does not break or slip off, it is unlikely that you will get HIV from having sex with a partner who is HIV positive.

There are a few ways to increase the chances that condoms protect you:

  • Ensure the condom has not expired by checking the expiry date; do not use expired condoms
  • Be careful not to tear the condom when taking it out of the packet
  • Use a water-or silicone-based lubricant to lower the chances the condom will break

Also, it is important to put the condom on correctly before you have genital contact. Check out our page on ‘Condoms’ for more information.

HIV can also be passed through sharing drug equipment, such as needs needles. Using new needles and other drug equipment is recommended every time you use drugs to prevent HIV and other infections. Have a look at our ‘Alcohol, drugs and sex’ page to learn more about how to keep yourself safe.

HIV is managed with daily prescription medication called antiretroviral therapy (ART). If you partner is taking ART as directed, this will lower the amount of virus in their body. This is called being “undetectable”. People know they are undetectable by having blood tests to monitor their amount of HIV in their body. If someone is undetectable (viral load under 200 copies/mL), they cannot transmit HIV through sex.

In BC, there are free medications you can take if a condom breaks or you do not use a condom. This medication is called “non-occupational exposure post-exposure prophylaxis (nPEP)”. nPEP work best if taken as soon as possible within 72 hours after exposure to HIV. If you think there is a chance you have been exposed to HIV, then it is important to talk with a health care provider who knows about HIV treatment to see if this is an option. nPEP is also available in all hospital emergency rooms, provincial prisons and some specific clinics. For more information about nPEP, have a look at our ‘Post-Exposure Prophylaxis (PEP)’ page. 

People who have a higher chance of getting HIV may be eligible to take daily ART medication to prevent HIV transmission from occurring; this is called “pre-exposure prophylaxis (PrEP)”. Research has show, when PrEP is used properly; it is more than 90% effective in preventing HIV. Note: PrEP does not protect you from other STI; use of condoms and barrier methods are still recommended even while taking PrEP. To learn more about PrEP, have a look at our ‘Pre-Exposure Prophylaxis (PrEP)’ and ‘HIV PrEP’ pages.


On average, how long does someone need to have chlamydia or gonorrhea for, before complications like PID, epididymitis develop?

The period of time it takes for complications to develop is not known, and will be different from person-to-person.

If you treat chlamydia and gonorrhea infections early, there are usually no other related health problems. However, delaying treatment or not treating STIs properly can lead to serious health complications.

Untreated chlamydia and gonorrhea can potentially cause the following complications:

  • Pelvic inflammatory disease (PID) is an infection of the reproductive organs, including the uterus (womb), fallopian tubes, and ovaries. Because PID can damage the reproductive organs (and potentially cause infertility), it is important to seek health care quickly. To learn more about PID, click here.
  • Epididymitis is when the epididymis is inflamed. The epididymis is a long, tightly coiled tube that lies above and behind each testicle. To learn more about epididymitis, click here.
  • Infertility – challenges with getting pregnant.
  • Ongoing pelvic pain, including painful periods.
  • Ectopic pregnancy is when a pregnancy occurs outside of the uterus (usually in the fallopian tube). If left untreated, this can be life-threatening.
  • Reactive arthritis is an autoimmune response, causing ongoing symptoms of urethritis, conjunctivitis and arthritis.

If you think you have an untreated STI, or are experiencing any symptoms, we would recommend seeing a health care professional. You can to go your regular family doctor, a walk-in clinic, or an STI clinic for these concerns. If you need help finding an STI clinic in your area, check out our ’Find a clinic’ tool.


How long does it take HIV test results to be accurate?

The period between getting HIV and when it will show up on a test is called a “window period”.

Window periods are based on averages and/or statistics from studies. There are a few different types of HIV tests and these tests have different window periods.

For more information about HIV window periods, click here.

For most people in BC, testing for HIV will involve either an antibody or a combined antigen and antibody test. Here is a brief explanation of these tests:

  • Antibody tests: These tests measure antibodies to HIV. It takes time after someone has been exposed to HIV for the body to make these antibodies. This type of test is used when tested using a point-of-care (POC, rapid) test.

    The window period for this test is 3 weeks to 3 months. Up to 95% of people will have antibodies by 6 weeks, and 99% after 3 months.
  • Antigen tests: antigens viral proteins; the antigen used to detect HIV is called p24 antigen. P24 antigen shows up in the blood soon after a person gets HIV.

    The 4th Enzyme Immunoassay Test (EIA) is a combined antigen/antibody test and is the standard HIV laboratory blood test used in BC.

    The window period is 6 weeks (when 99% of people would test positive, if they got HIV).
  • Nucleic acid amplification test (NAAT): looks for genetic material of HIV in the blood. It is sometimes referred to as an “early HIV test” or “RNA test”. This test is only used by doctors or nurses under specific circumstances, such as a recent high-risk exposure to HIV and/or they are having HIV-related symptoms.

    The window period is 10-12 days (when 90% of people would tests positive, if they got HIV) to 6 weeks (when 99% of people would test positive, if they got HIV).

There is a tool you can use to calculate HIV window periods, click here to learn more.


Which STIs can I get from kissing?

Kissing is, for the most part, a safe activity; most STIs are not commonly passed; however, herpes (sometimes referred to “cold sores”) is one that can be easily passed.

Sexually transmitted infections (STI) like gonorrhea and human papillomavirus (HPV) can also be passed with deep kissing, but they are not commonly passed this way.

Syphilis sores can be in the mouth, so it is possible to get syphilis from deep kissing. However, it is not a common way for syphilis to be passed.

Have a look at our ‘Know your chances’ and ‘Types of STIs’ pages to learn more about these STIs and how they are passed.


How long does it take to get results?

It depends what types of tests you did and where you had testing done. Generally, STI testing can take anywhere from a few days to up to 2 weeks for results to be ready. 

At our BCCDC clinics, we typically say 8 days after you tested. 

If you had done PAP testing, it will usually take a few weeks. 

Usually when you test at a clinic, they will provide you with a card that indicates when your test results will be ready and how to access them. If not, you can connect with the health care provided, who did the tests, to find out.

To learn more about results, have a look at our ‘Getting Results’ page.


If I have herpes, do I have to tell my partners?

Herpes simplex virus (HSV) is a very common with an estimated up to 89% of Canadian having it. However, HSV carries a lot of stigma that can lead to anxiety, fear and misinformation about it.

HSV is passed by skin-to-skin contact from a person who has it. It is commonly passed when people have symptoms (outbreaks, sore that are healing or prodromal symptoms), but it can also be passed even if you do not have symptoms (this is called “asymptomatic shedding”).

To lower your chances of passing HSV to your partners, there are a few things you can do:

  • Avoiding sexual contact while symptomatic
  • Using condoms and barriers during sex
  • Considering taking antiviral medication, particularly if you have frequent outbreaks

Note: Condoms offer good protection, but do not completely prevent passing HSV because they do not cover the entire genital area.

With regard to telling partners, this can be difficult. Telling your partners lets them make informed choices. There may be situations where you do not feel safe telling your partners. Ultimately, it is your choice; informing partners is not required as it is with some other STIs (such as, chlamydia, gonorrhea, syphilis, HIV).

Have a look at our Herpes: A Patient’s Guide to learn more about HSV; there is a useful section on telling partners.


How accurate are tests for herpes?

It is important to understand the different types of herpes simplex virus (HSV) tests that are available in BC; these include:

  • HSV polymerase chain reaction (PCR) is a swab test looks for the genetic material of HSV.

    It is the test most commonly used, and involves swabbing sores. It is very accurate (nearly 100%).

    If you test positive, this test will tell you which type (HSV-1 or HSV-2), and because the test is from sores on your body, you will know where you have HSV.

    Window period: accurate once you have sores, usually within 2-21 days.
  • HSV type-specific serology (HSV TSS) is a blood test that is used under specific circumstances, as it provides limited information that may or may not be useful for you to know. HSV TSS is very accurate.

    If you test positive, this test will tell you if you have antibodies for HSV-1 and/or HSV-2. This test cannot tell you where on your body you have HSV.

    Window period: 12-16 weeks.

To ensure your results are accurate, you need to consider when to get tested. Each of the above tests have window periods. A window period is the period of time between getting HSV and when it will show up on a test. To learn more about window periods, click here.


How long will I have genital warts (HPV)?

Genital warts are caused by the human papillomavirus (HPV). It is one of the most common sexually transmitted infections (STIs). 

There are over 100 types of HPV. About 40 of them can affect the anus/rectum, genitals and less commonly, the mouth and throat. HPV is sexually transmitted through skin-to-skin contact. This includes sexual contact such as, genitals rubbing together, penetrative sex (vaginal/internal genital or anal/rectal intercourse), oral sex, sharing sex toys, and hands on genitals. HPV may still be present even if there are no visible warts or when the warts are gone. Wearing condoms can help to reduce, but not eliminate the chances of passing HPV from one partner to another.

For the majority of people, the virus will clear the body on its own without causing symptoms/warts or problems. 

For those who do get symptoms (genital warts), most of these will eventually go away with or without having them treated, often within 18-24 months. Once your genital warts are gone, this does not mean the HPV infection is gone or cured. Genital warts can come back and you can get HPV again from a partner who has it.

There are now vaccines that protect against the more common HPV types. The vaccine will not help you get rid of HPV if you already have it, but it can prevent future infections. To learn more about the HPV and other vaccines, click here.


I tested positive for chlamydia but my partner tested negative, and I have had no sex with anyone else. How can this happen?

Of course, each situation will be unique, here is some general information on how one person can test positive for chlamydia and/or gonorrhea, while their partner tests negative.

Chlamydia and gonorrhea are common sexually transmitted infections (STIs). Often people have no symptoms or slight symptoms that they may or may not noticed. To learn more about symptoms, click here.

Chlamydia and gonorrhea can be passed by oral, vaginal/internal genital or anal/rectal sex.

If someone tested positive for chlamydia and/or gonorrhea, and their sexual partner tested negative, there are a few possibilities that could make this happen. Some of these include:

  • As most people do not have symptoms, it is possible the person (who tested positive) could have had chlamydia/gonorrhea from a previous relationship, and has not passed it to their partner yet. It is never 100% that you will pass an STI when you have sex.
  • It is possible that the person who tested negative for chlamydia/gonorrhea actually has it, but did not give a good specimen to be tested. For example, when providing a urine specimen for testing, it is recommended that the person not urinate 1-2 hour before the test. If the person did urinate during that time, then the test may not be accurate.
  • It is possible the person did test positive for chlamydia/gonorrhea, but if they are worried about getting in trouble, they could say they tested negative.
  • With the chlamydia/gonorrhea test, there is also the small chance of the person having a false positive test result. For example, the chlamydia test is positive but you actually do not have chlamydia.
  • It is also possible the person (who tested negative) had chlamydia/gonorrhea in the past, but was treated with antibiotics for an unrelated medical condition that also happened to get rid of the chlamydia/gonorrhea at the same time.

Fortunately, chlamydia and gonorrhea are curable with proper antibiotics. 

When a person tests positive for chlamydia and/or gonorrhea, it is recommended that all sexual partners be tested and treated regardless of their results. 


If I take all my gonorrhea/chlamydia medication and don’t have any sex for a week, will it be safe for me to have sex with my partner?

It depends on a few different things; if you and your partner(s):

  • completed medication as instructed;
  • did not have any sex for 7 days from when you started your medication; and
  • have no ongoing or new STI symptoms;

Then it would be safe for you to resume sex with your partner(s).

If you and your partner(s) have not, then it may not be safe for you to resume sex.

If you and your partner(s) did not take all of your medication or had any difficulties taking your medication (such as, missing any doses, side effects, vomiting shortly after taking your medication), you should return to your health care provider to discuss being re-treated.

If you and your partner(s) had sex while taking your medication, then you may be passing gonorrhea/chlamydia to each other, and getting treated again should be discussed with your health care provider. 

If you and your partner(s) have any symptoms after taking all your medication, you should avoid sex and see your health care provider. You may need more testing or medication.

Taking all your medication for gonorrhea and chlamydia is important so, that you do not get any complications, and to prevent passing these infections on to your partner(s).

When taken as instructed by your health care provider, the medications for gonorrhea and chlamydia work very well at getting rid of the infection. 

We do not usually recommend having another test to check if the medication worked, unless you are having symptoms, are pregnant or your health care provided told you to do so. If you need to retest for gonorrhea and chlamydia, then you should do so, at least 4 weeks after you finished your medication.

For anyone who tests positive for gonorrhea and/or chlamydia, it is recommended that you retest in 6 months because people often get the infection again from an untreated or new partner.


Can HIV be transmitted by sharing cigarette, with or without blood on it?

You cannot get HIV from sharing a cigarette because HIV is not passed by saliva. This is why it is not passed through kissing or sharing eating utensils either.

If there is old or dried blood on the cigarette, you will not get HIV because HIV does not live for long outside the body.

If there is a fresh blood and you had an open area (like a sore or cut) on your mouth, it is possible that you could get HIV. However, we do not see HIV being passed this way. 

HIV is passed by blood, semen (including pre-cum), rectal fluids, vaginal fluids and breast milk. HIV can only be passed when the virus in one of these fluids gets into the body of an HIV-negative person. This can happen sexually during condomless vaginal/internal genital and anal/rectal sex. HIV is unlikely to be passed through oral sex or rimming. HIV can also be passed through sharing needles or other drug equipment. To learn more about how HIV and STIs are transmitted, see our ‘Know your chances’ page.


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