Trichomoniasis, sometimes known as “trich,” is caused by the parasite Trichomonas vaginalis, according to the Cleveland Clinic. It is found in semen and vaginal fluid of infected people so it is most commonly transmitted via sexual activity. This means that vaginal-penile, vaginal-vaginal, anal, and oral sex as well as genital touching without ejaculation can all spread this disease.
On the other hand, engaging in casual contact such as sharing foods and drinks, kissing, or holding hands is not sufficient to transmit the infection. The Clinic also clarifies that being “dirty” does not cause trichomoniasis nor can it be caused by a urinary tract infection.
However, while we often think of sexually transmitted diseases (STDs) as only being transmitted via sexual activity — after all, it says it in the name — there are ways that trichomoniasis can be spread that do not involve sexual activity.
Trichomoniasis can be transmitted to your baby at birth
Healthline states that trichomoniasis is generally treated with either metronidazole (Flagyl) or tinidazole (Tindamax). Both partners will need to be treated and they should abstain from sex until the infection is gone.
If a pregnant woman does not treat her trichomoniasis, however, there can be complications. The American Pregnancy Association states that if you don’t treat your infection you can pass trichomoniasis to your baby at birth. However, they add that this is quite rare. Having an infection increases the chances of pre-term delivery. It also make it more likely that the baby will have a low birth weight. These factors can influence the baby’s health and overall development as well as how long they may need to remain in the hospital following birth. Metronidazole is considered to be a safe treatment option for pregnant mothers (per BabyCenter). Also, your baby can be treated with antibiotics if necessary.
Other non-sexual ways that trichomoniasis might spread
Whether trichomoniasis can be transmitted in other ways is a bit controversial. A 2014 case study in the Indian Journal of Sexually Transmitted Diseases and AIDS reported on a 67-year-old woman who presented at the hospital with what appeared to be trichomoniasis. The authors suggested that trichomoniasis should be considered in older women who are not sexually active since their changing vaginal acidity and reduced estrogen levels make them more prone to this infection. The authors further pointed to reports in the literature showing the transmission of the disease through shared bathing water, towels, toilet seats, and swimming pools. However, they did note that large epidemiologic studies are needed to confirm their hypothesis.
Everlywell writes, however, that catching trichomoniasis from a toilet seat is an “urban legend.” They state that people who find themselves infected may wonder why they have it after not being sexually active for a while. They further explain that you could have a trichomoniasis infection “indefinitely.” You could also experience symptoms at varying levels over the course of several years without really knowing what’s causing them or you might attribute them to something else like a yeast infection or a urinary tract infection. This could lead you to think you didn’t contract the infection through sex because you caught the disease years prior.
YourSexualHealth confirms that sharing wet towels could spread the disease. They also mention genital touching that is not sexual in nature as a way of spreading the infection.