The Most Common STD You've Never Heard Of

The sexually transmitted diseases (STDs) or sexually transmitted infections (STIs) most people know and would think of as common is gonorrhea, chlamydia, or even HIV. But there is one sexually transmitted disease that is common, but people never talk about it like they should. It’s called Trichomoniasis.

I can hear it now: “Tric o-what?”

Trichomoniasis is caused by a parasite called trichomonas vaginalis, a type of single-celled organism (or protozoon).

In women, trichomoniasis can cause a foul-smelling vaginal discharge, genital itching, and painful urination. Pregnant women who have trichomoniasis might be at higher risk of delivering their babies prematurely.

That said, there’s a lot we don’t know about trichomoniasis—and not a lot is being done to stem its spread. Even though trichomoniasis is common, it’s not a reportable disease, which means that local and state health departments and the CDC don’t require new cases to be reported when they’re diagnosed.

This also means that public health programs aren’t putting as much effort into tracking or controlling its transmission as they might with other STIs.

As a matter of fact, Trichomoniasis (or “Trich”) is the most common curable STD. In the United States, CDC estimates that there were more than two million trichomoniasis infections in 2018. However, only about 30% develop any symptoms of trichomoniasis. Infection is more common in women than in men.

Older women are more likely than younger women to have been infected with trichomoniasis.