Trichomonas vaginalis: Clinical relevance, pathogenicity and diagnosis

Abstract

Trichomonas vaginalis is the etiological agent of trichomoniasis, the most prevalent non-viral sexually transmitted disease worldwide. Trichomoniasis is a widespread, global health concern, and occurring at an increasing rate. Infections of the female genital tract can cause a range of symptoms, including vaginitis and cervicitis, whilst infections in males are generally asymptomatic. The relatively mild symptoms, and lack of evidence for any serious sequelae, have historically led to this disease being under diagnosed, and under researched. However, growing evidence that T. vaginalis infection is associated with disease states with high morbidity in both men and women has increased the efforts to diagnose and treat patients harbouring this parasite. The pathology of trichomoniasis results from damage to the host epithelia, caused by a variety of processes during infection, and recent work has highlighted the complex interactions between the parasite and host, commensal microbiome, and accompanying symbionts. The commercial release of a number of nucleic acid amplification tests (NAATs) has added to the available diagnostic options. Immunoassay based Point of Care testing is currently available, and a recent initial evaluation of a NAAT Point of Care system has given promising results, which would enable testing and treatment in a single visit.

Clinical and Laboratory Testing for Trichomonas vaginalis Infection

“…vaginalis is a free-living protozoan that can colonize mucosal epithelial surfaces. Infection may manifest as a fulminant yellow/ gray-green discharge and cause vulvar-vaginal itching and odor (15). Upon clinical examination, punctate friability of the cervix (called a strawberry cervix) may be observed.…”

Genital Trichomonas vaginalis is rare among female attendees at a Sydney metropolitan sexual health clinic

“…Trichomonas vaginalis (TV) is the most common non‐viral sexually transmitted infection worldwide; 1 however, it is not a notifiable infection in Australia 2 . TV is associated with pelvic inflammatory disease, preterm delivery and an elevated risk of HIV transmission 1 . In women, more than half (50–80%) of the TV infections are asymptomatic 1 .…”

“…TV is associated with pelvic inflammatory disease, preterm delivery and an elevated risk of HIV transmission 1 . In women, more than half (50–80%) of the TV infections are asymptomatic 1 . In men, infections are mostly asymptomatic and usually self‐limiting, and there are few associations with adverse clinical outcomes 1,3 …”

“…In women, more than half (50–80%) of the TV infections are asymptomatic 1 . In men, infections are mostly asymptomatic and usually self‐limiting, and there are few associations with adverse clinical outcomes 1,3 …”

BspA and Pmp proteins ofTrichomonas vaginalismediate adherence to host cells

“…T. vaginalis continue to increase and remain an underestimated threat due to the 327 often asymptomatic progress of infection(Edwards et al, 2016); T. vaginalis is apparently more 328 often a commensal than a parasite. Any T. vaginalis infection, including asymptomatic ones, is 329 accompanied by small inflammatory reactions of the affected host tissue, which are caused by 330 several kinds of different processes.…”