Epidemiology and Treatment of Trichomoniasis

Abstract

Trichomonas vaginalis is the most common nonviral sexually transmitted infection (STI) in the world. It was once thought to be a nuisance STI, but it is now being recognized as an important source of reproductive morbidity and a facilitator of HIV transmission and acquisition, and thus it is an important public health problem. The prevalence of T. vaginalis varies greatly by geography and risk group, but is more common among persons of African descent and appears to increase with age, though this may be a screening phenomenon. Wet mount and culture are simple diagnostics, but have lower sensitivity than nucleic acid amplification techniques presently approved for women only. Single dose (2 g) metronidazole (MTZ) for both the index patient and their sexual partners is the preferred treatment. High rates of retest positivity are found after single-dose treatment which are likely due to clinical resistance rather than re-infection and/or drug resistance.

High rates of double-stranded RNA viruses and Mycoplasma hominis in Trichomonas vaginalis clinical isolates in South Brazil

“…vaginalis isolates have occurred in recent years, supporting the evidence that resistance is on the rise (Klebanoff et al, 2001;Schwebke and Barrientes, 2006;Miller and Nyirjesy, 2011;Kissinger, 2015). Though the mechanism of metronidazole resistance in T. vaginalis from treatment failures is not well understood, one hypothesis is that the resistance of T. vaginalis to metronidazole occurs through several stages based on the significant reduction and eventual loss of activity of ferredoxin and pyruvate:ferredoxin oxidoreductase (PFOR), two enzymes involved in drug activation.…”

Clinical and Laboratory Testing for Trichomonas vaginalis Infection

“…These estimates are population dependent, with very high rates among some groups and almost no disease in others. In Europe, recent population level studies have estimated the prevalence of disease to be Ͻ1% in countries with chlamydia rates similar to those in the United States, suggesting a geographic fluctuation in the underlying presence of disease that is not well described or understood (5). In the United States, geographic fluctuation of rates is observed, but the ratio of trichomonas to chlamydia infections remains similar (6).…”

“…Research studies of men with NGU suggest that T. vaginalis is responsible for 10 to 12% of these cases of urethritis (11), one of the most common reasons why men Ͻ50 years old seek health care. Certain high-risk populations may warrant routine screening, such as women attending STD clinics, women in correctional facilities, women living in high-prevalence regions, men with urethritis, and sexual partners of infected women (4,5,12). However, programmatic decisions to offer screening should be based on local epidemiologic data whenever possible.…”

Trichomonas vaginalis and Human Immunodeficiency Virus Coinfection Among Women Under Community Supervision: A Call for Expanded T. vaginalis Screening

“…15 Although research has indicated that effective T. vaginalis control may reduce HIV transmission and acquisition, 16 the infection is asymptomatic in the majority of cases, 17 so it is rarely screened for and often remains untreated. 18 …”

“…19 Another study found that black women had T. vaginalis rates that were ten times higher than white women, constituting a significant health disparity. 17 Unlike other STIs, T. vaginalis infection disproportionately affects older women, 18 who are also overrepresented in the criminal justice system. A national profile shows that women in the criminal justice system are typically in their early to mid-thirties.…”