January 27, 2026, 9:53 am | Read time: 6 minutes

Trichomoniasis, also known as trichomonas infection, is one of the most common sexually transmitted infections (STIs) worldwide. According to estimates by the World Health Organization (WHO), around 156 million people are infected with trichomoniasis every year—most of them without knowing it^.1 As the symptoms are often mild or non-specific, the infection often remains untreated and has long-term health consequences. Find out here from expert Dr. Anne-Cathrin Stahr, a specialist in gynaecology in Munich, how you can avoid infection, detect the disease, and treat it.

What Is Trichomoniasis?

“Trichomoniasis is caused by the protozoan Trichomonas vaginalis and affects both women and men,” says Dr. Stahr. “The infection primarily targets the urogenital tract. In women, the vagina, urethra, and cervix are usually affected. In men, the pathogen can colonize the mucous membrane of the urinary tract and prostate. In approximately 30 percent of cases, it leads to inflammation and can cause a range of symptoms, some of which may be quite unpleasant.”

Symptoms

In Women

A common symptom in women includes unpleasant itching and burning in the genital area. Increased vaginal discharge is often reported, which may be frothy and yellowish-green with a very unpleasant and pungent odor. There may also be pain when urinating or during sexual intercourse. Redness and swelling of the vaginal mucosa is also possible, sometimes accompanied by intermenstrual bleeding.

In Men

In men, the symptoms are usually milder or even completely absent. If symptoms do occur, they can manifest themselves in the form of irritation of the urinary tract, a slight burning sensation after urination or ejaculation. More rarely, there may also be discharge from the penis or the anal area.

Is the Infection Similar to Gonorrhea?

Both infections are sexually transmitted diseases and can cause similar symptoms. However, trichomoniasis and gonorrhea are two different infections. While gonorrhea is caused by the bacterium Neisseria gonorrhoeae, trichomoniasis is an infection with the parasite Trichomonas vaginalis. A distinction can only be made by means of special tests carried out by a specialist.

Risk Factors and Infection

Unprotected Sexual Intercourse

Trichomoniasis is mainly transmitted through unprotected vaginal, anal, or oral sex, with changing partners further increasing the risk.

Age

People under the age of 25 are particularly at risk, as sexually transmitted infections generally occur more frequently in this age group due to frequent changes of sexual partners.

Weakened Immune System

A weakened immune system, whether due to chronic illnesses, certain medications, or stress, can further increase the risk of infection, as the body has fewer defenses against pathogens.

Existing Infection

A pre-existing sexually transmitted infection (STI), such as chlamydia or gonorrhea, can also increase susceptibility to trichomoniasis, as mucous membranes that are already inflamed are more susceptible to further pathogens.

Genetics and Hygiene

Genetic factors tend to play a subordinate role, while a lack of intimate hygiene can indirectly influence the risk. Not only infrequent but also incorrect cleaning can promote the disease.

Humid Environment

Although the parasite survives in warm, damp environments, infection through shared damp towels in swimming pools or toilets is theoretically possible, but extremely rare.

Why Is the Infection So Common?

Often Symptom-Free

As the infection is often asymptomatic, it can go completely unnoticed and be passed on unintentionally.

No Immunity

There is also no immunity to the infection. Anyone who has been infected once and has been treated can still become infected again at any time.

Test Only if Suspected

A test for trichomoniasis is not part of standard preventive care, as can be the case with chlamydia or HPV. It is usually only carried out if symptoms occur or if there is an increased risk of infection, e.g., if sexual partners change frequently or if the partner has a known infection. It can be useful to be tested if you suspect you have had unprotected sexual intercourse.

Diagnostic Procedure

“To diagnose trichomoniasis, your gynecologist or urologist will take a swab from the vagina or urethra. The pathogens can sometimes be identified directly under the microscope, but this method is not always reliable. A culture test, in which the sample is cultured in the laboratory, provides more accurate results, but this takes longer. The most reliable method is the PCR test, which detects the genetic material of the pathogens and recognizes even small quantities. There are also rapid tests that provide a result quickly, but are used less frequently than PCR tests,” explains Dr. Stahr when asked by FITBOOK.

Treatment

Trichomoniasis is effectively treated with antibiotics. To avoid re-infection, sexual partners should also always be treated. During treatment, it is advisable to refrain from sexual intercourse so as not to impair healing and to prevent a so-called ping-pong infection.

When Are Those Affected No Longer Infectious?

After taking the medication, most patients are no longer infectious within a week. Retesting after around four weeks is recommended to ensure the success of the treatment, as an untreated infection can lead to serious complications.

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Possible Consequences of Untreated Trichomoniasis

Persistent Symptoms

Symptoms such as itching, burning, pain during urination or sexual intercourse, and foul-smelling discharge may persist or worsen.

Inflammation of the Urinary and Reproductive Organs

In women, trichomoniasis can lead to inflammation of the vagina, cervix, bladder, and rectum. A chronic trichomonas infection can lead to dysplasia, i.e., precancerous growths on the cervix. In men, it can lead to urethritis or painful prostate problems.

Increased Risk of Other Sexually Transmitted Infections (STIs)

Inflamed mucous membranes are more vulnerable to additional infections, such as chlamydia, gonorrhea, and HIV.

Complications During Pregnancy

There is a risk of premature birth, low birth weight of the baby, or even infection of the newborn during birth.

Trichomoniasis – Widespread and Yet Underestimated

Despite its widespread prevalence, trichomoniasis is often underestimated as it is often asymptomatic. While research is increasingly focused on sexually transmitted infections such as HIV or HPV, better diagnostic methods and more effective prevention strategies for trichomoniasis remain a challenge. Early detection and treatment are crucial to minimize health risks and prevent further spread. The best protection is the use of condoms and regular check-ups, especially with frequently changing sexual partners.

With expert advice from Dr. med. Anne-Cathrin Stahr from the Rosenstrasse Gynecological Practice in Munich.