Non-Sexual Transmission of STIs


Can STIs Be Transmitted Non-sexually?

There are numerous common myths about the transmission of sexually transmitted infections (STIs). Some people believe that you can get an STI from animals, a toilet seat, or kissing. Many of these speculations are untrue, but some actually do contain some interesting truth. There is always a very small chance that an infection can be spread in a peculiar way, but for the most part, nonsexual transmission of STIs is rare. If you or someone you know has an STI or you think you may have contracted one, see a doctor as soon as possible to limit the spread of the infection, whether sexual or nonsexual.

Oral Sex

It is often falsely assumed that because oral sex isn’t penetrative sex, it does not carry the same risk for sexually transmitted infections. However, oral sex does put a person at high risk for contracting or transmitting STIs. The mucous membranes in the mouth and throat, like the mucous membranes of the genitals, are entry points to the body and ample living environments for the viruses and bacteria that cause many of the most common STIs. Chlamydia, Herpes simplex virus (HSV) 1 and 2, Human Papillomavirus (HPV), and syphilis can all be contracted via unprotected oral sex. Some people even transmit HSV 1 (oral herpes) to the genitals or visa versa.1 Oral HIV transmission is much less likely but still possible. Cuts or open sores (such as those caused by other STIs) in the mouth allow for HIV in semen or vaginal fluid to have a more direct route to the blood stream, which therefore increases the risk of spreading the virus during oral sex.2 

Contact Without Clothing

During any kind of activity where the genitals of two different people may come into contact, such as mutual masturbation or foreplay, there is a risk for spreading STIs. The risk increases if ejaculation or vaginal lubrication occurs, as these fluids can facilitate the spread of infection. Herpes and HPV are the most common STIs that can be spread in this manner, as they produce outbreaks on the skin that may come into direct contact with another person’s genitals.1 Contact without clothing usually can only lead to the spread of STIs when one person’s genitals come into contact with an infected person’s genitals, semen or vaginal fluid. Other parts of the body do not facilitate the spread of STIs unless semen or vaginal fluid is present on them, or they contain an open sore.


When a pregnant female is infected with an STI, she can pass the infection to her infant during vaginal childbirth. Chlamydia, gonorrhea, Hepatitis B, syphilis, and HPV can be spread to infants when they pass through the vaginal canal. Herpes can also be spread in this way, but this is rather uncommon unless the mother is experiencing an outbreak at the time of the birth. HIV is not usually spread during childbirth, but can be contracted by the child during pregnancy. Some infections, such as chlamydia, can be especially dangerous for an infant to contract so early in life and can cause painful eye infections or even potentially life threatening lung infections.1 It is very important for pregnant females to be tested for sexually transmitted infections. If a female is suffering from an STI at the time of childbirth, doctors can decide to perform a cesarean section in order to avoid transmitting the infection to the baby.

Breast Feeding

Some STIs can be transmitted to an infant during breastfeeding. HIV is carried by breast milk; therefore, females with HIV should not breastfeed to avoid passing the infection to a child. Syphilis can cause open sores and chancres on other parts of the body besides the genitals, so if a sore is present on or near the nipple, females with syphilis should not breastfeed. However, syphilis infection is not carried via breast milk and as long as no sores are present, will not be spread to an infant in this way. Gonorrhea, chlamydia, hepatitis ABC, HPV, trichomoniasis, pubic lice, and bacterial vaginosis cannot be transmitted via breast milk and breastfeeding while infected with one of these STIs is considered safe.3

Sharing Needles

Sharing needles is a very high-risk activity for contracting blood-borne diseases such as HIV and Hepatitis B or C.4 Other STIs such as chlamydia and gonorrhea are not typically transmitted via blood and therefore cannot be transmitted by sharing needles. It is important that used needles are never reused, and that any other instruments or tools that come onto contact with blood are safely disposed of or properly cleaned to help stop the spread of life threatening blood-borne infections.

Tattoos and Piercings

The needles used for tattoos and piercings can transmit blood-borne infections such as HIV or hepatitis B.5 Usually this is not a problem at professional tattoo and piercing shops. These companies should follow strict health regulations to prevent the spread of disease. Tattoos and piercings done outside of a professional setting cause a high risk of HIV or hepatitis transmission because the needles and tools may not be cleaned and disposed of properly. If you are considering getting a tattoo or piercing, it is best that you see a professional and understand their health codes in order to protect yourself from contracting blood-borne STIs and other infections.


Autoinoculation is the spread of infection from one part of the body to other, uninfected, parts of the body. This can happen when a person is infected with chlamydia, touches his or her genitals, and then touches their eyes. The eyes can then be infected with chlamydia. Similarly, herpes infections can be spread from the genitals to the mouth or eyes. This is not possible with all STIs, but can be a real problem for the ones it does apply to. Keeping hands clean and away from any infection in the body can prevent autoinoculation.1

Kissing and Sharing Drinks

It is very rare that saliva can transmit STIs through activities like kissing and sharing drinks. When transmission of STIs via saliva in the mouth does occur, kissing is more likely to spread STIs than sharing drinks because kissing puts the mucous membranes of the mouth in close or direct contact. Herpes simplex 1 can be contracted from kissing. Herpes simplex 2 can also be spread through kissing, as it can occur in the mouth as well as on the genitals. Syphilis may also be transmitted through the mouth. Usually, in order for syphilis or herpes to be transmitted via the mouth, there would have to be an outbreak of sores or chancres in the mouth of an infected person.1 Blood-borne infections such as HIV and hepatitis are not typically spread via saliva.6

Toilet Seats

Most STIs cannot be transmitted via objects such as a toilet seat. Trichomoniasis may be transmitted if the toilet seat is wet or damp, but pubic lice, gonorrhea, herpes, bacterial vaginosis, syphilis, chlamydia, HPV, HIV, and hepatitis B and C typically cannot be transmitted this way.1 Some studies have shown that people who use a latrine or outhouse instead of a flushing toilet are at an increased risk for contracting trichomoniasis. This is likely because of the close proximity to the urine and feces of people who may have trichomoniasis, not because the infection is spread by surfaces.7 This information also supports the idea that STIs are not typically transmitted by tanning beds or locker room surfaces.


Bathtubs do not typically facilitate the transmission of STIs such as herpes, syphilis, gonorrhea, chlamydia, HPV, HIV, or hepatitis.1 In some cases, sharing bathwater with an infected person could lead to the transmission of trichomoniasis. This is, however, more likely in places where bathwater is reused several times for a community of people.7

Public Pools and Hot Tubs 

Most public pools and hot tubs are usually cleaned with chemicals that kill the types of bacteria and viruses that lead to the spread of STIs, so it is not common for people to contract sexually transmitted infections in this way. If a pool is not cleaned regularly, trichomoniasis can be spread via the water in the pool. This is a very rare occurrence, and pools and hot tubs are not typically a concern for the transmission of STIs compared to other, higher risks.

Contaminated Food

The only STI that can be transmitted via food is hepatitis A. Hepatitis A is predominantly carried in feces, so when it is transmitted via food it is usually because produce was not washed properly or because an infected person preparing the food did not wash their hands after using the restroom. In some places, where public water sources are not sanitized or monitored, hepatitis A can be carried in water. Developed cities usually have chlorination or some other treatment in place to rid their public water sources of hepatitis A.1

Unsanitary Medical Procedures and Cultural Practices

Sexually transmitted infections such as Hepatitis B or C and trichomoniasis can be transmitted during cultural or medical procedures when the tools or hands of the person performing the procedure are not thoroughly cleaned.7 In some parts of the world, practices such as cosmetic genital surgeries or circumcision are done on the bodies of many different people with little to no sanitation in between. This can lead to the spread of many infections, including sexually transmitted infections. Oral herpes may be transmitted via dentist’s tools when they are not disinfected.4 Medical professionals typically make sure to clean their tools effectively between patients, so there should not be a reason to worry that your local clinic will give you an STI as long as it follows general health standards.

Sharing Towels, Clothing, and Bedding

Some STIs can be spread by sharing cloth material such as clothing and bedding, but many cannot. Herpes, syphilis, and HIV are not usually spread via clothing, sheets, or towels. Bacterial vaginosis is not caused by shared bedding or clothing, but using wet towels or bathing suits in general may lead to the bacterial imbalances that cause bacterial vaginosis. Trichomoniasis can be spread via damp clothing or towels. Although rare, pubic lice can be contracted via shared bedding and clothing.1 Prolonged exposure to contaminated clothing can lead to the spread of HPV. Materials infected by the discharges caused by chlamydia can transmit the infection to other people. This is especially common when chlamydia infects the eyes.4

Sharing Razors

Sharing razors with a person who is infected with HIV or hepatitis can put you at risk for contracting these infections because of the potential for cuts that provide blood-borne diseases with a means to enter the body of an uninfected person. Transmission of STIs in this way is not highly likely, but it is possible.

Sharing Tooth Brushes

Some people experience bleeding of the gums when they brush their teeth. Thus sharing a toothbrush with someone who is infected with a blood-borne STI such as hepatitis or HIV could be slightly risky. Herpes can also be transmitted via toothbrush if the mouth of an infected person contains an open sore or outbreak. As with many other non-sexual activities, contraction of STIs in this way is very rare.4

Douches and Sex Toys

Failing to clean sex toys and douches can lead to the spread of STIs such as trichomoniasis, HPV, and hepatitis B. Transmission can occur from person to person when these items are shared, or a person could reinfect themself with an infection that they have already been treated for. Douching can also lead to bacterial vaginosis, as it disrupts the normal balance of bacteria in the vagina. To prevent the spread of infection via douching and using sex toys, be sure to clean these items after every use. Most experts also recommend not douching at all; the vagina has its own cleaning mechanism, so it really is not necessary.1


Animals do not spread sexually transmitted infections to humans. There is sometimes confusion over a bacteria carried by birds known as Chlamydia psittaci. This bacteria is related to, but not the same as, the bacteria known as Chlamydia trachomatis that causes genital chlamydia in humans. Thus, there is a form of chlamydia carried by birds, but this bacteria does not cause the same symptoms in humans as sexually transmitted chlamydia.4 

Living or Spending Time with Infected Individuals

Sexually transmitted infections are not airborne. Thus, you cannot get an STI from sitting next to an infected person or being in the same room as them. Household objects such as doorknobs or dishes do not typically lead to the transmission of STIs. When a person is infected with an STI, it is not likely that other people living in the same home as that person will be infected unless they are engaging in sexual activity with the infected individual or are in direct contact with that person’s genitals, blood, semen, or vaginal fluid.5


To prevent the spread of STIs, condoms should be used every time sexual activity occurs. Condoms are the only form of contraception that help to protect against STIs. Protection in the form of condoms or dental dams should even be used during oral sex. It is important for sexually active individuals to get tested often and communicate with potential partner(s) about their STI status. STIs do not always produce symptoms, so a person could spread an STI without even knowing that they have one. Once a person knows they have an STI, treatment should be sought out immediately. Many STIs can lead to dangerous complications if left untreated. The longer the infection is ignored, the more people could be at risk for contracting it. While being treated for an infection, it is crucial to take any medications exactly as instructed by a doctor or clinician. A patient should never stop taking medication before they are instructed to do so. This could cause the body to be resistant to medications and contribute to the development of antimicrobial-resistant infections.

To avoid contracting STIs in non-sexual ways, the best thing for an individual to do is practice good hygiene. Washing hands frequently (especially before and after touching the genitals of other people and after using the restroom), cleaning sex toys and tools used on the genitals after use, and washing clothing and towels regularly can greatly increase personal hygiene and dramatically decrease the chances of transmitting STIs or any other types of infections. Needles and other objects that come into contact with human blood should not be shared, as this is one of the most common ways to contract an STI non-sexually.

Concluding Remarks

In general, the transmission of sexually transmitted infections results when mucous membranes of one individual (such as those in the mouth, eyes, or genitals) come into contact with the semen, vaginal fluid, genitals, and sometimes blood, of an infected person. The spread of STIs is not typically facilitated by everyday objects, public places, or skin on other parts of the body that are not the mouth and genitals, except under some special circumstances. Although some non-sexual modes of STI transmission are theoretically possible, they are not common. Almost all STI transmission can be avoided by participating in hygienic activities as a part of living healthy.


  1. “Sexually Transmitted Infections.” Women’s Health (n.d.): 119-43. Web. 7 April 2016.
  2. “Can I Get HIV from Oral?” San Francisco AIDS Foundation, n.d. Web. 19 May 2016.
  3. “How You Can Get an STD Without Having Sex.” STD Exposed Sexual Health Blog. N.p., 23 June 2015. Web. 7 April 2016.
  4. “MSDSonline & KMI Are Now…” MSDS Solutions. N.p., n.d. Web. 16 May 2016.
  5. “New York City Department of Health and Mental Hygiene.” New York City Department of Health and Mental Hygiene, n.d. Web. 7 April 2016.
  6. “Prevention and Vaccination: FAQ.” Hepatitis B Foundation: Prevention and Vaccination, n.d. Web. 19 May 2016.
  7. Crucitti, Tania et al. “Non-Sexual Transmission of Trichomonas Vaginalis in Adolescent Girls Attending School in Ndola, Zambia.” Ed. Landon Myer. PLoS ONE 6.1 (2011): e16310. PMC. Web. 18 May 2016.

Last Updated 19 May 2016.