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Transmitting STIs: An Unwelcome Gift

There are a lot of myths about how STIs are transmitted.  This page provides the facts.

Test your knowledge about STIs with this True/False Quiz:

  1. You can get an STI from hugging someone or sitting on a toilet seat. False
  2. You can get an STI from having sex with someone who is already infected with an STI. True
  3. You can get an STI from shaking someone’s hand. False
  4. You can get an STI from passing sex toys back and forth with an infected person. True
  5. Condoms can protect you from STIs. True
  6. The birth control pill can protect you from some STIs. False
  7. Having only one partner can protect you from STIs. False

Four ways STIs are passed on:

1. Fluid Transmission (most common)

  • Most STIs are passed on when an infected person’s vaginal fluid, anal fluid or semen enters your body through mucus membranes in your vagina*, penis*, anus (butthole), or mouth.
  • Some STIs, such as HIV and hepatitis A and B, are also passed on when an infected person’s blood gets inside your bloodstream through mucus membranes or open sores, cuts, tiny scratches, or through sharing injection or snorting drug equipment.

2. Skin-to-Skin Transmission

  • Herpes, molluscum, HPV, and parasitic STIs are passed on through skin-to-skin contact, such as when your genitals or your mouth touch an infected person’s genitals or mouth.

3. Indirect Transmission (less common)

  • Sometimes, STIs are passed on by sharing sex toys with an infected person if the toy hasn’t been disinfected or if a new condom isn’t used when a new partner uses it.
  • Some parasitic STIs, such as scabies and pubic lice (crabs) can live outside the body for a short period of time and can be spread by sharing a bed, clothes, or towels.

4. Vertical Transmission (rare)

  • A pregnant person can pass on an STI to their baby before and during childbirth.

For more information on ways to reduce the risk of transmitting STIs, check out Protecting Yourself and Your Partners from STIs [Link].

If you have questions about this topic, feel free to contact one of our peer educators. [Link]


*We know that these aren’t the words everyone uses for their bodies (eg. trans folks), and support you using the language that feels best for you.

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