How Do You Get An STI – STD?

Last Updated on June 4, 2020 by Nancy Carteron, MD, FACR

Because STIs/STDs (sexually transmitted infections or diseases) are infections that are commonly/have a high probability of being spread from person to person through unprotected intimate contact, this also means there is a chance an STI could be contracted through non-intimate contact as well.

As a result, it’s important to clarify the many ways one can contract an STI by both intimate/sexual and non-intimate/non-sexual contact.

Sexual Contact

Traditionally, sexual contact is thought of as vaginal intercourse, however, sexual contact is a much broader term and includes activities not always assumed to carry a risk of contracting or transmitting an STI.

Not only does sexual contact include vaginal intercourse, it also includes kissing, genital touching, the use and sharing of ‘sex-toys’, oral sex, anal sex, and vaginal sex.

Bacterial STIs are most often transmitted through contact with the fluids that carry the bacteria (semen, vaginal secretions, and saliva) or contact with an open sore secreting the bacteria through pus, mucous and bloody fluids. Consequently, any activity in which an exchange of fluids or physical contact with a bacteria-carrying fluid occurs poses a risk of transmission.

Viral and parasitic STIs are commonly transmitted by both fluids (semen, vaginal secretions, blood, and saliva) and skin-to-skin contact.

The risk of transmission for all forms of STIs is increased when contact occurs along the mucous membranes as they are porous and allow a point of entry for viruses, bacteria, and parasites. Mucous membranes are tissues that line body cavities or canals such as the throat, nose, mouth, urethra, rectum, and vagina.

Non-Sexual Contact

Although STIs are categorized as such because they are commonly and have a high probability of being transmitted via unprotected sexual contact, The STI Project talks about a few STIs that fall into a grey area and have been considered both an STI and just a common infection.

Mononucleosis, intestinal parasites, and vaginitis, for example, are often talked about without reference to STIs.

However, we include them on this website because certain age demographics and populations contract them almost exclusively via sexual contact.

Nevertheless, it’s important not to make assumptions about someone’s mode of transmission and to be aware of all the non-sexual ways one can contract an STI as well.

Non-sexual contact includes virtually everything else not described above and can encompass sharing food, sharing needles, breastfeeding, child-birth, sharing bedding, and surgical procedures. Because STIs can be transmitted via fluids or skin-to-skin contact it’s easy to envision the transmission of STIs in a non-sexual way too.

In day-care centers, molluscum contagiosum and pubic lice commonly occur through skin-to-skin contact.

Hepatitis and HIV are frequently transmitted via blood in the sharing of intravenous drug needles.

Vaginitis, PID, and NGU can arise from IUDs and catheters moving healthy bacteria outside of the vagina or into the urethra.

Herpes and syphilis can be passed from mother to child during child-birth.

The list goes on.

For more non-sexual transmission examples specific to a particular STI, check out the STD In-Depths section.

– – – –

References:

• External STI/STD References
• STD Blogs & Forums

Were you surprised by some of the ways you can contract an STI? Does this change your opinion about STIs/STDs? Share your thoughts in the comments section below!

More On This:

• What is an STI?
• About STDs – Your Ultimate Reference Guide
• STD vs. STI – Why The STI Project uses STD
• STD Testing Clinics
• STD Prevention