Trichomoniasis is caused by a small single-celled protozoan parasite called Trichomonas vaginalis. Anyone who is sexually active can become infected, with women being more commonly affected. Women over 40 are thought to be affected twice as often as younger women. Trichomoniasis in men very often does not manifest itself with clinical symptoms, which is why they become asymptomatic carriers. Pregnant women who have trichomoniasis may be at higher risk of preterm birth. When trichomoniasis causes symptoms, they can range from mild irritation to severe inflammation. The incubation period is between 5 and 28 days after infection, but it can vary widely, and symptoms can come and go. In this way, diagnosis and adequate treatment are often not carried out, as a result of which the spread and chronicity of the infection is facilitated, hiding the risk of even cancer. About 20% of those affected become infected again within three months of treatment. A big role is also played by not examining sexual partners. It is extremely important to examine and treat the sexual partner or partners, even if they have no symptoms. Sexual contact should be avoided during therapy and for 7 to 10 days after its completion. It is recommended to re-examine before resuming sexual contact. Research shows that infection with the parasite is associated with an increased risk of infection with other sexually transmitted infections, including gonorrhea, human papillomavirus, herpes simplex virus and, last but not least, HIV. The reason is that the inflammation present facilitates the entry of other sexually transmitted pathogens. Trichomonas vaginalis infection in men has been found to cause asymptomatic urethritis and prostatitis. In the prostate, infection can cause chronic inflammation that can eventually lead to prostate cancer. Trichomoniasis is believed to be underdiagnosed worldwide due to various factors, including lack of routine testing, low sensitivity of a commonly used diagnostic technique (wet microscopy), and nonspecific symptomatology. Self-diagnosis and self-treatment, without adequate laboratory tests, may also contribute to the spread. Multiple molecular detection methods are recommended, including several validating nucleic acid amplification tests (NAATs) and an antigen detection test. Trichomoniasis can complicate the interpretation of Pap smears, increasing the number of false-positive results. Because inflammation leads to changes in cells and this can be misinterpreted as a precancerous condition. Trichomoniasis increases the rate of sterility in men and women. In women, there is the development of salpingitis, and in men, due to the release of toxic products, sperm motility is reduced.It is also important to mention the role of the bacterial vaginal flora, because in this way the mucous membrane is protected from injuries and the penetration of pathogenic microorganisms, including the reproduction of trichomonas. Complications of non-treatment depend on gender. Thus, in women, untreated infections can progress to urethritis or cystitis, and in the long term, they are associated with pelvic inflammatory disease, infertility, and an increased risk of cervical cancer. In men, untreated infections are associated with chronic prostatitis, epididymitis, infertility, and an increased risk of prostate cancer. References: Kimberly A Workowski, Gail A Bolan; Sexually transmitted diseases treatment guidelines, MMWR. Recommendations and Reports, 2015