Trichomonas

Abstract

Trichomonas vaginalis is a flagellated eukaryotic microorganism, which parasitizes the human urogenital mucosa. This pathogen is responsible for the most prevalent, nonviral, sexually transmitted infection worldwide; despite the high prevalence of the disease, relevant aspects of the pathophysiology of T. vaginalis are still obscure, and the impact of the infection on public health is greatly underestimated, especially in developing countries. Recently, trichomoniasis has been classified as a neglected infection. In order to establish the infection in humans, T. vaginalis has evolved a number of sophisticated and multifaceted colonization and virulence strategies, based both on production of toxic molecules and enzymes and on subversion of the host immune response. Even if trichomoniasis is primarily considered as a source of morbidity in the human reproductive tract, increasing interests of parasitologists and clinicians have recently focused on severe complications associated with Trichomonas infection, such as adverse pregnancy outcomes, facilitation of HIV transmission, and association with cervical and prostate cancer. Nitroimidazole derivatives remain the sole treatment of trichomoniasis, and despite an ever increasing number of metronidazole-resistant isolates has been reported in the last years, effective alternative therapies are not yet available. All these aspects of pathobiology of T. vaginalis will be discussed in the present chapter, on the basis of the most recent results of molecular and “omics” investigations.