From the Guidelines
Trichomoniasis is caused by the protozoan parasite Trichomonas vaginalis, which primarily infects the urogenital tract, and its pathophysiology involves attachment to epithelial cells, secretion of hydrolytic enzymes, and alteration of the local microbiome, leading to inflammation and increased susceptibility to other STIs, including HIV, as noted in studies such as 1. The pathophysiology of trichomoniasis begins when the parasite attaches to epithelial cells in the vagina or male urethra using specific adhesion proteins and surface lipophosphoglycan.
- Once attached, T. vaginalis secretes various hydrolytic enzymes including cysteine proteases and pore-forming proteins that damage host cell membranes, leading to cell lysis.
- The parasite also releases factors that degrade the protective mucus layer and alter the local microbiome, reducing beneficial lactobacilli and increasing pH, as discussed in 1. This creates an environment favorable for parasite growth and colonization.
- T. vaginalis can phagocytose host cells, bacteria, and even red blood cells for nutrition.
- The host immune response involves neutrophil infiltration, causing inflammation that manifests as vaginal discharge, itching, and erythema in women, or urethritis in men, as reported in 1. The parasite can form biofilms and has mechanisms to evade immune detection, including antigenic variation and molecular mimicry.
- Chronic infection can lead to increased susceptibility to other STIs, including HIV, due to microabrasions in the epithelium and increased local inflammation, as highlighted in 1. The most effective treatment for trichomoniasis is oral metronidazole, which has resulted in cure rates of approximately 90%-95%, as noted in 1.
From the Research
Pathophysiology of Trichomoniasis
The pathophysiology of trichomoniasis involves the infection of the genitourinary tract by the protozoan parasite Trichomonas vaginalis 2. This infection can cause a range of symptoms, including vaginitis, cervicitis, urethritis, and pelvic inflammatory disease (PID) 2, 3. T. vaginalis is site-specific for the genitourinary tract and has been isolated from virtually all genitourinary structures 2.
Clinical Manifestations
The clinical manifestations of trichomoniasis can vary, but common symptoms include vaginal discharge, urethral discharge, and genital itching 2, 3. In some cases, the infection can be asymptomatic, making screening and diagnosis important for preventing the spread of the disease 2, 3.
Transmission and Acquisition
Trichomonas vaginalis is primarily transmitted through sexual contact, and the infection can increase the risk of acquiring and transmitting other sexually transmitted infections (STIs), including HIV 2, 3. The parasite can also be transmitted from mother to child during childbirth, potentially leading to respiratory tract infections in neonates 3.
Diagnosis and Treatment
Diagnosis of trichomoniasis is typically made through wet mount microscopy, direct visualization, or DNA amplification techniques 2, 3. Treatment usually involves a single dose of metronidazole, although alternative treatments such as tinidazole may be used in cases of metronidazole resistance 2, 4. Recent studies have also investigated the use of non-nitroimidazole drugs, such as amixicile, as potential alternative treatments for trichomoniasis 5.
Epidemiology and Prevention
Trichomoniasis is a highly prevalent STI, with a worldwide incidence of 5-75% 3. Prevention of the disease involves screening and treatment of infected individuals, as well as education and awareness about the risks of STIs 2, 6. Concomitant treatment of sexual partners is also recommended to prevent the spread of the disease 2, 3.