Trichomonas vaginalis

Trichomonas vaginalis is a flagellated protozoan parasite, 10-30 µm in diameter, and is responsible for one of the most widespread sexually transmitted diseases worldwide, trichomoniasis or "trich". The main signs of a Trichomonas infection in women are abdominal pain, itching, and presence of a foul-smelling discharge with abundant leukocytes, while in men the infection is mostly asymptomatic, although it can sometimes lead to urethritis, prostatitis, and epididymitis. Infection with this organism is also associated with severe complications, such as infertility and enhanced predisposition to neoplastic transformation in cervical tissues:

Most people infected with Trichomonas are asymptomatic. Symptomatic infections are characterized by a white discharge from the genital tract and itching. Diagnosis depends on finding trophozoites in secretions of the genital tract from men or women. In cases where the numbers of organisms are very low, the trophozoites can be cultured to increase their numbers.

There is no cyst in the life cycle, so transmission is via the trophozoite stage. These motile cells have four flagella (visible in the video if you look carefully) and single nucleus. There is also a median rod called the axostyle which is characteristic of the trichomonads however, this is not clearly visible without staining the cells.

Pathogenesis of Trichomonas infections occurs by cytopathogenicity against vaginal epithelial cells. Adhesion of the parasite to the target cell is essential for the maintenance of infection and for cytopathogenicity. Flattened, adherent forms can be seen in the last two clips in this video.

Trichomonas vaginalis is an anaerobic, flagellated protozoan, a form of microorganism. The parasitic microorganism is the causative agent oftrichomoniasis, and is the most common pathogenic protozoan infection of humans in industrialized countries. Infection rates between men and women are the same with women showing symptoms while infections in men are usually asymptomatic. Transmission takes place directly because thetrophozoite does not have a cyst. The WHO has estimated that 160 million cases of infection are acquired annually worldwide. The estimates for North America alone are between 5 and 8 million new infections each year, with an estimated rate of asymptomatic cases as high as 50%. Usually treatment consists of metronidazole and tinidazole.