How common is Trichomonas?

Trichomonas is one of the most common but least talked-about STIs worldwide. Millions of people are infected each year, and most don’t know they have it. At Better2Know, we test for Trichomonas in around 17% of all bookings.

Trichomonas is curable, testing is simple, and you can book confidential tests through Better2Know or at your nearest sexual health clinic. Below, we’ll explore how common Trichomonas really is, who’s most at risk, and how you can avoid getting it and protect your sexual health.

Keep reading to find out more.

Trichomonas is caused by the protozoan Trichomonas vaginalis. This parasite can infect the vagina, urethra, and penis, and it spreads through sexual contact without a condom-primarily vaginal sexual intercourse-as well as through sharing sex toys. You can learn more about non-sexual transmission routes here.

Like most STIs, the infection can be transmitted even when you don’t notice any symptoms. It also causes genital inflammation, increasing the risk of acquiring or passing on HIV and other STIs. Many national statistics under-estimate true infection numbers because Trichomonas isn’t routinely included in every STI screen. Fortunately, a vaginalis infection is fully curable with the right antibiotics, so spotting it early through testing can prevent complications and break chains of transmission between sex partners.

Trichomonas is one of the most common non-viral STIs globally. The World Health Organization estimates over 150 million new infections annually among people aged 15 to 49, with global prevalence rates of approximately 4.9% in women and 0.5% in men.

Key regional highlights include:

• African region: Prevalence among women reaches approximately 12%, making sub-Saharan Africa the highest-burden area worldwide.
• United States: Prevalence is around 2.1% for females and 0.5% for males. Over two million trichomoniasis infections occurred in the U.S. in 2018 alone, according to CDC surveillance data.
• Australia: Urban clinics report low positivity rates (<1%), but trichomonas remains highly prevalent in some remote and Indigenous communities. You can read more about how common Trichomonas is in Australia on our blog.

Because the infection isn’t routinely tested for everywhere, official numbers are often lower than the reality.

Certain groups face a higher risk of Trichomonas:

• Women are more likely to contract trichomoniasis than men, and older women are more likely to have it than younger women.
• People with multiple or new sexual partners, those with other STIs, and communities with limited access to regular sexual health screening are disproportionately affected.
• Trichomonas prevalence is notably higher among non-Hispanic Black women and men compared to other racial groups, and higher rates are consistently linked with lower socioeconomic status. Testing in targeted settings reveals much higher positivity rates compared to the general population.
• Trichomonas is more frequently detected in sexually active people in their 30s and 40s than in teenagers, partly because its prevalence remains stable or increases with age and infections can persist unnoticed for years.

Up to 70% of infected individuals show no symptoms. When symptoms do appear-typically 5 to 28 days after exposure-women may experience:

• A yellow-green, fishy-smelling vaginal discharge
• Vulval itching, irritation inside the lower genital tract
• Pain during intercourse
• Discomfort when urinating
• Inflamed cervix
• Penile discharge or pain when urinating (in men)

Because the symptoms of Trichomonas can mimic other STIs like Chlamydia, it can be misattributed. Untreated cases increase HIV infection risk by 1.5 times. Pregnant women with Trichomonas face a higher risk of premature birth, preterm delivery, premature rupture of membranes, and having babies early. It can also lead to low birth weight in newborns, making it a real concern for women’s health and pregnancy outcomes.

Symptoms alone can’t reliably diagnose trichomoniasis-a lab test is needed. Healthcare providers typically use nucleic acid amplification tests (NAATs) on swabs or urine, which are highly sensitive.

A typical appointment involves answering questions about your symptoms and recent sexual partners, then providing a vaginal swab, urethral swab, or urine sample. The process is quick and usually only mildly uncomfortable. Better2Know offers clinic visits, nurse home visits, and home sample collection kits with private, fast laboratory analysis.

If trichomonas is detected, trichomoniasis is treated with metronidazole or tinidazole antibiotics. Treatment usually lasts for 7 days or can be given as a single dose, and symptoms typically improve within a few days of starting treatment. Both partners should be treated simultaneously to prevent reinfection, because reinfection occurs in about 1 in 5 people within 3 months. It’s important that the infection clears fully before resuming sexual contact, and you should use a new condom each time to reduce risk.

When people think of STIs, they often picture Chlamydia, Gonorrhoea, or HIV. Yet Trichomonas often outnumbers Gonorrhoea and Syphilis in estimated annual new infections globally. Because it often causes no symptoms and isn’t always part of routine STI panels, it may actually be more widespread than many better-known infections.

Although Trichomonas is a very common STI, there’s plenty you can do to protect yourself:

• Use condoms correctly every time you have vaginal sex-and use a new condom on sex toys, washing them between users.
• Limit your number of sexual partners and talk openly with any new partner about STI testing and history.
• Get regular screening for STIs, including specific testing for Trichomonas, especially when entering a new relationship.
• If you’re diagnosed, ensure all current sex partners receive treatment and avoid intercourse until you’ve both completed antibiotics and any symptoms have cleared-this is essential to prevent reinfection.

Is Trichomonas getting more common or just more frequently detected?

It’s difficult to say definitively. Changes in testing practices and the adoption of more sensitive diagnostic methods mean we’re finding more existing infections. As more sexually active people include Trichomonas in their sexual health checks, apparent case numbers may rise even if the underlying infection rate is stable.

Why do some countries test for Trichomonas more often than others?

Higher testing uptake in places like South Africa (approximately 33% of Better2Know bookings) reflects a combination of higher background prevalence and stronger clinical awareness from disease control programmes. In Ireland (~10%), Trichomonas may be genuinely less common but is also likely under-recognised.

Should I worry about Trichomonas if I only have one sexual partner?

Having one partner lowers your risk, but doesn’t remove it-either person could have picked up trichomonas in a previous relationship without knowing. Consider getting a full STI check together before deciding to stop using condoms.

Trichomonas is far more common than most people realise-with millions of new infections each year and the vast majority producing no symptoms at all, only testing can uncover what you can’t see. The reassuring reality is that trichomoniasis is straightforward to diagnose and fully curable, and looking after your sexual health protects both you and your partner in the long term.

Don’t wait for symptoms before acting. If you’re sexually active-especially with new or multiple partners-book a confidential STI screen with Better2Know today, online or by phone. With rapid results, a wide choice of clinics and home testing options, and supportive advisors ready to guide your next steps, taking control of your sexual health is one of the best investments you can make in your wellbeing and future relationships.