Trichomoniasis ( trich) is an infectious disease caused by the parasite Trichomonas vaginalis.[ When symptoms occur, they typically begin 5 to 28 days after exposure.][ Symptoms can include itching in the genital area, a bad smelling thin vaginal discharge, burning with urination, and pain with sex.][ Having trichomoniasis increases the risk of getting HIV/AIDS.][ It may also cause complications during pregnancy.][
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Trichomoniasis is a sexually transmitted infection (STI) most often spread by vaginal, oral, or anal sex.[ It can also spread through genital touching (manual sex).][ Infected people may spread the disease even when symptoms are absent.][ Diagnosis is by finding the parasite in the vaginal fluid using a microscope, culturing the vaginal fluid or urine, or testing for the parasite's DNA.][ If present, other STIs should be tested for.][
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Methods of prevention include not having sex, using condoms, not douching, and being tested for STIs before having sex with a new partner.[ Although not caused by a bacterium, trichomoniasis can be cured with certain (metronidazole, tinidazole, secnidazole).][ Sexual partners should also be treated.][
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There were about 122 million new cases of trichomoniasis in 2015.[ It occurs more often in women than men.][ Trichomonas vaginalis was first identified in 1836 by Alfred Donné.]
Signs and symptoms
Most people infected with Trichomonas vaginalis do not have any symptoms and it can be undetected for years.[ Trichomoniasis symptoms . cdc.gov] Sometimes trichomoniasis can be confused with chlamydia because the symptoms are similar.
Complications
Trichomoniasis is linked to several serious complications.
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Trichomoniasis is associated with an increased risk of transmission and infection of HIV.
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Trichomoniasis may cause a woman to deliver a low-birth-weight or premature birth infant.
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The role of Trichomonas infection in causing cervical cancer is unclear. However, trichomonas infection may be associated with co-infection with high-risk strains of HPV.
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T. vaginalis infection in males has been found to cause asymptomatic urethritis and prostatitis. In the prostate, it may create chronic inflammation that may eventually lead to prostate cancer.
Causes
The human genital tract is the only reservoir for this species. Trichomonas is transmitted through sexual or genital contact.
The single-celled protozoan produces mechanical stress on host cells and then ingests cell fragments after cell death.
Genetic sequence
A draft sequence of the Trichomonas genome was published on January 12, 2007, in the journal Science, confirming that the genome has at least 26,000 genes, a similar number to the human genome. An additional approximately 34,000 unconfirmed genes, including thousands that are part of potentially transposable elements, brings the gene content to well over 60,000.[ Scientists crack the genome of the parasite causing trichomoniasis . Physorg.com. Jan. 12, 2007.]
Diagnosis
There are three main ways to test for trichomoniasis.
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The first is known as saline microscopy. This is the most commonly used method and requires an endocervical, vaginal, or penile swab specimen for examination under a microscope.
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The second diagnostic method is culture, which has historically been the "gold standard" in infectious disease diagnosis. Trichomonas vaginalis culture tests are relatively cheap but their sensitivity is still somewhat low (70–89%).
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The third method includes the nucleic acid amplification tests (NAATs), which are more sensitive.
Prevention
Use of male or female condoms may help prevent the spread of trichomoniasis,[ Vaginitis/Trichomoniasis: Reduce your risk , American Social Health Association. Retrieved March 12, 2008.] although careful studies have never been done on how to prevent this infection. Infection with trichomoniasis through water is unlikely because Trichomonas vaginalis dies in water after 45–60 minutes, in thermal water after 30 minutes to 3 hours, and in diluted urine after 5–6 hours.
There are no routine standard screening requirements for the general U.S. population receiving family planning or STI testing.
The advent of new, highly specific, and sensitive trichomoniasis tests presents opportunities for new screening protocols for both men and women.
Several strategies have been found to improve follow-up for STI testing, including email and text messaging as reminders of appointments.
Screening
Evidence from randomized controlled trials for screening pregnant women who have no symptoms of infection with trichomoniasis and treating women who test positive for the infection have not consistently shown a reduced risk of preterm birth.
Treatment
Treatment for both pregnant and non-pregnant women is usually with metronidazole,[ Vaginitis/Trichomoniasis :Treatment for trichomoniasis , American Social Health Association. Retrieved March 12, 2008.] by mouth once.
For 95–97% of cases, infection is resolved after one dose of metronidazole.
Topical treatments are less effective than oral antibiotics due to Skene's gland and other genitourinary structures acting as reservoirs.
Vaginal boric acid can be useful against resistant trichomoniasis.
Epidemiology
There were about 58 million cases of trichomoniasis in 2013.[Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, and TB. Division of STD Prevention. Trichomoniasis - CDC Fact Sheet. 2012.]
See also
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Trichomonas gallinae is a related pathogen of birds
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