Trichomoniasis in Black Women: The STI Most Panels Miss

Trichomoniasis is caused by a parasite, Trichomonas vaginalis, and it is the most common curable sexually transmitted infection in the country. The CDC estimated more than two million infections in the United States in 2018. The reason it matters so much for Black women is the burden: in national NHANES testing, 8.9% of Black women carried the infection, the highest rate of any group measured. That is close to one in eleven. Most of them had no idea, because about 70% of people with trich have no symptoms at all.

When you get "tested for STIs," the routine panel almost always means chlamydia and gonorrhea, sometimes with HIV and syphilis blood work. Trichomoniasis is not on that list by default. A clinician has to order it separately. That gap is the core problem: a parasite that infects nearly one in eleven Black women is left off the test most women assume covers everything. So a woman can test "negative" year after year and still be carrying it.

The silence makes it worse. Because roughly 70% of infections cause no symptoms, there is nothing to push you to ask. When symptoms do appear, they are easy to write off: thin discharge that may be yellow-green or have an odor, itching or irritation, discomfort with urination, or pain during sex. None of that is specific to trich, which is exactly why the CDC says you cannot diagnose it from symptoms alone. A lab test is the only way to know.

The single most useful thing you can do is name the test. Tell your clinician: "I want to be tested for trichomoniasis, with a NAAT." A NAAT (nucleic acid amplification test) is the most sensitive way to find the parasite, far better than the old method of looking at a wet-mount slide under a microscope, which misses many infections. The sample can be a vaginal swab or a urine test. If a routine STI panel is being run anyway, this is a small addition, but you usually have to request it specifically.

Two situations deserve extra attention. If you are pregnant and have symptoms, ask to be tested and treated, because trich in pregnancy is linked to delivering early and to low birth weight. And if you are living with HIV, trich testing matters more, not less: the CDC recommends retesting roughly three months after treatment because reinfection is common.

Trich is curable, but left alone it is not benign. The inflammation it causes in the genital tract makes it easier to acquire HIV. A systematic review and meta-analysis found that people infected with Trichomonas vaginalis were about 1.5 times as likely to acquire HIV as people without it. For a community already carrying a heavy HIV burden, an untreated, easily curable infection that raises that risk is a problem worth closing. If HIV prevention is on your radar, our guide to HIV prevention for Black women covers PrEP and testing.

In pregnancy, the stakes are different but real. A large study of nearly 14,000 women found that Trichomonas vaginalis at mid-pregnancy was associated with low birth weight and preterm delivery. One caution worth being honest about: treating trich during pregnancy has not been proven to prevent preterm birth, so the goal is detection and symptom relief, not a guarantee. The association is still a reason to get tested and treated if you have symptoms while pregnant.

Trich is cured with antibiotics, but two details decide whether the cure sticks. First, the regimen. In 2021 the CDC changed its guidance for women. Women should now take metronidazole 500 mg twice a day for 7 days, not the older single 2-gram dose. This came out of a randomized trial led by Dr. Patricia Kissinger: the multi-day course cut the rate of women still testing positive at follow-up roughly in half compared with the single dose. (Men are still treated with the single 2-gram dose.)

Second, partners. Trich bounces back when one partner is treated and the other is not, a cycle called ping-pong reinfection. Every current sex partner needs treatment at the same time, and both of you should avoid sex until treatment is finished and symptoms are gone. The CDC also recommends retesting about three months after treatment, even if your partner was treated, because reinfection is that common. One more practical note: skip alcohol while taking metronidazole and for the window your clinician specifies, because the combination can make you sick.

Any OB-GYN, primary care provider, or sexual health clinic can order a trich NAAT and prescribe the cure. The key is to ask for it specifically, because it is not on the default panel. If you want a clinician who will hear the request without making you over-explain, you can find a Black OB-GYN or sexual health provider in our directory. Bring one sentence to the visit: "Please test me for trichomoniasis with a NAAT, and tell me how my partner gets treated too." If you have recurring pelvic pain alongside infections, our explainer on pelvic inflammatory disease in Black women covers when that becomes urgent.