Trichomoniasis (trich) is an infectious disease caused by the parasite Trichomonas vaginalis.[2] About 70% of women and men do not have symptoms when infected.[2] When symptoms do occur they typically begin 5 to 28 days after exposure.[1] Symptoms can include itching in the genital area, a bad smelling thin vaginal discharge, burning with urination, and pain with sex.[1][2] Having trichomoniasis increases the risk of getting HIV/AIDS.[1] It may also cause complications during pregnancy.[1]

Other namesTrich[1]
Micrograph showing a positive result for trichomoniasis. A trichomonas organism is seen on the top-right of the image.
SymptomsItching in the genital area, bad smelling thin vaginal discharge, burning with urination, pain with sex[1][2]
Usual onset5 to 28 days after exposure[1]
CausesTrichomonas vaginalis (typically sexually transmitted)[2][1]
Diagnostic methodFinding the parasite in vaginal fluid, microbial culture, testing for the parasites DNA[1]
PreventionNot having sex, using condoms, not douching[1]
MedicationAntibiotics (metronidazole or tinidazole)[1]
Frequency122 million (2015)[3]

Trichomoniasis is a sexually transmitted infection (STI) which is most often spread through vaginal, oral, or anal sex.[1] It can also spread through genital touching.[1] People who are infected may spread the disease even when symptoms are not present.[2] Diagnosis is by finding the parasite in the vaginal fluid using a microscope, culturing the vagina or urine, or testing for the parasite's DNA.[1] If present other STIs should be tested for.[1]

Methods of prevention include not having sex, using condoms, not douching, and being tested for STIs before having sex with a new partner.[1] Trichomoniasis can be cured with antibiotics, either metronidazole or tinidazole.[1] Sexual partners should also be treated.[1] About 20% of people get infected again within three months of treatment.[2]

There were about 122 million new cases of trichomoniasis in 2015.[3] In the United States, there are about 2 million women affected.[1] It occurs more often in women than men.[1] Trichomonas vaginalis was first identified in 1836 by Alfred Donné.[4] It was first recognized as causing this disease in 1916.[5]

Signs and symptoms

Most people infected with trichomonas vaginalis do not have any symptoms and can be undetected for years.[6] Symptoms experienced include pain, burning or itching in the penis, urethra (urethritis), or vagina (vaginitis). Discomfort for both sexes may increase during intercourse and urination. For women there may also be a yellow-green, itchy, frothy, foul-smelling ("fishy" smell) vaginal discharge. In rare cases, lower abdominal pain can occur. Symptoms usually appear within 5 to 28 days of exposure.[7] Sometimes trichomoniasis can be confused with chlamydia because the symptoms are similar.[8]


Trichomoniasis is linked to two serious complications.

  • Trichomoniasis is associated with increased risk of transmission and infection of HIV.[9][10]
  • Trichomoniasis may cause a woman to deliver a low-birth-weight or premature infant.[9]
  • The role of trichomonas infection in causing cervical cancer is unclear, although trichomonas infection may be associated with co-infection with high-risk strains of HPV.[11]
  • 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.[12][13]


Lifecycle of Trichomonas

The human genital tract is the only reservoir for this species. Trichomonas is transmitted through sexual or genital contact.[14]

The single-celled protozoan produces mechanical stress on host cells and then ingests cell fragments after cell death.[15]

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 ~35,000 unconfirmed genes, including thousands that are part of potentially transposable elements, brings the gene content to well over 60,000.[16]


There are three main ways to test for Trichomoniasis.

  • 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.[17] The presence of one or multiple trichomonads constitutes a positive result. This method is cheap but has a low sensitivity (60-70%) often due to an inadequate sample, resulting in false negatives.[18][19]
  • The second diagnostic method is culture, which has historically been the "gold standard" in infectious disease diagnosis. Trichomonas Vaginalis culture tests are relatively cheap; however, sensitivity is still somewhat low (70-89%).[20]
  • The third method includes the nucleic acid amplification tests (NAATs) which are more sensitive.[20] These tests are more costly than microscopy and culture, and are highly sensitive (80-90%).[21]


Use of male condoms or female condoms may help prevent the spread of trichomoniasis,[22] although careful studies have never been done that focus 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.[23]

Currently there are no routine standard screening requirements for the general U.S. population receiving family planning or STI testing.[24][25] The Centers for Disease Control and Prevention (CDC) recommends Trichomoniasis testing for females with vaginal discharge[26] and can be considered for females at higher risk for infection or of HIV-positive serostatus.[24]

The advent of new, highly specific and sensitive trichomoniasis tests present opportunities for new screening protocols for both men and women.[24][27] Careful planning, discussion, and research are required to determine the cost-efficiency and most beneficial use of these new tests for the diagnosis and treatment of trichomoniasis in the U.S., which can lead to better prevention efforts.[24][27]

A number of strategies have been found to improve follow-up for STI testing including email and text messaging as reminders of appointments.[28]


Evidence from a randomized controlled trials for screening pregnant women who do not have symptoms for infection with trichomoniasis and treating women who test positive for the infection have not consistently shown a reduced risk of preterm birth.[29][30] Further studies are needed to verify this result and determine the best method of screening. In the US, screening of pregnant women without any symptoms is only recommended in those with HIV as trichomonas infection is associated with increased risk of transmitting HIV to the fetus.[31]


Treatment for both pregnant and non-pregnant women is usually with metronidazole,[32] by mouth once.[31] Caution should be used in pregnancy, especially in the first trimester.[33] Sexual partners, even if they have no symptoms, should also be treated.[23]

For 95-97% of cases, infection is resolved after one dose of metronidazole.[26][34] Studies suggest that 4-5% of trichomonas cases are resistant to metronidazole, which may account for some “repeat” cases.[33][9] Without treatment, trichomoniasis can persist for months to years in women, and is thought to improve without treatment in men.[9] Women living with HIV infection have better cure rates if treated for 7 days rather than with one dose.[31][35]

Topical treatments are less effective than oral antibiotics due to Skene's gland and other genitourinary structures acting as a reservoir.[36]


There were about 58 million cases of trichomoniasis in 2013.[37] It is more common in women (2.7%) than males (1.4%).[38] It is the most common non-viral STI in the U.S., with an estimated 3.7 million prevalent cases and 1.1 million new cases per year.[39][40] It is estimated that 3% of the general U.S. population is infected,[21][41] and 7.5-32% of moderate-to-high risk (including incarcerated) populations.[42][43][44][45][46][47][48][49]


  1. "Trichomoniasis". Office on Women's Health. August 31, 2015. Archived from the original on 27 March 2016. Retrieved 21 March 2016.
  2. "Trichomoniasis - CDC Fact Sheet". CDC. November 17, 2015. Archived from the original on 19 February 2013. Retrieved 21 March 2016.
  3. GBD 2015 Disease and Injury Incidence and Prevalence, Collaborators. (8 October 2016). "Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1545–1602. doi:10.1016/S0140-6736(16)31678-6. PMC 5055577. PMID 27733282.
  4. Wiser, Mark (2010). Protozoa and Human Disease. Garland Science. p. 60. ISBN 9781136738166. Archived from the original on 2016-04-02.
  5. Pearson, Richard D. (2001). Principles and Practice of Clinical Parasitology. Chichester: John Wiley & Sons. p. 243. ISBN 9780470851722. Archived from the original on 2016-04-02.
  6. "STD Facts - Trichomoniasis". Archived from the original on 2013-02-19.
  7. Trichomoniasis symptoms Archived 2013-02-19 at the Wayback Machine.
  8. "Can Trichomoniasis Be Confused With Chlamydia?". Retrieved 18 July 2019.
  9. Secor W, Meites E, Starr M, Workowski K (2014). "Neglected parasitic infections in the United States: trichomoniasis". Am J Trop Med Hyg. 90 (5): 800–804. doi:10.4269/ajtmh.13-0723. PMC 4015567. PMID 24808247.
  10. Kissinger P, Adamski A (September 2013). "Trichomoniasis and HIV interactions: a review". Sex Transm Infect. 89 (6): 426–33. doi:10.1136/sextrans-2012-051005. PMC 3748151. PMID 23605851.
  11. Donders GG; et al. (2013). "Association of Trichomonas vaginalis and cytological abnormalities of the cervix in low risk women". 8 (12): e86266. doi:10.1371/journal.pone.0086266. PMC 3875579. PMID 24386492.
  12. Caini, Saverio; Gandini, Sara; Dudas, Maria; Bremer, Viviane; Severi, Ettore; Gherasim, Alin (2014). "Sexually transmitted infections and prostate cancer risk: A systematic review and meta-analysis". Cancer Epidemiology. 38 (4): 329–338. doi:10.1016/j.canep.2014.06.002. ISSN 1877-7821. PMID 24986642.
  13. Stark, Jennifer R.; Judson, Gregory; Alderete, John F.; Mundodi, Vasanthakrishna; Kucknoor, Ashwini S.; Giovannucci, Edward L.; Platz, Elizabeth A.; Sutcliffe, Siobhan; et al. (2009). "Prospective Study of Trichomonas vaginalis Infection and Prostate Cancer Incidence and Mortality: Physicians' Health Study". JNCI Journal of the National Cancer Institute. 101 (20): 1406–11. doi:10.1093/jnci/djp306. PMC 2765259. PMID 19741211.
  14. "Trichomoniasis - CDC Fact Sheet". Archived from the original on 19 February 2013. Retrieved 12 January 2011.
  15. Midlej V.; Benchimol M. (2010). "Trichomonas vaginalis kills and eats- evidence for phagocytic activity as a cytopathic effect". Parasitology. 137 (1): 65–76. doi:10.1017/S0031182009991041. PMID 19723359.
  16. Scientists crack the genome of the parasite causing trichomoniasis Archived 2009-01-04 at the Wayback Machine. Jan. 12, 2007.
  17. Epstein, Aaron; Roy, Subir (2010). "Chapter 50: Vulvovaginitis". In Goodwin, T. Murphy (ed.). Management of Common Problems in Obstetrics and Gynecology (5th ed.). Wiley-Blackwell. p. 228. ISBN 978-1405169165. Archived from the original on 2017-02-15. In 80% of cases, the diagnosis of trichomoniasis is confirmed by microscopic examination of saline wet mount, with the observation of motile trichominondas; their shape is "football-like" with moving flagella.
  18. Fouts AC, Kraus SJ (1980). "Trichomonas vaginalis: reevaluation of its clinical presentation and laboratory diagnosis". J Infect Dis. 141 (2): 137–143. doi:10.1093/infdis/141.2.137. PMID 6965976.
  19. Schwebke JR, Burgess D (2004). "Trichomoniasis". Clin Microbiol Rev. 17 (4): 794–803. doi:10.1128/cmr.17.4.794-803.2004. PMC 523559. PMID 15489349.
  20. Nye MB, Schwebke JR, Body BA (February 2009). "Comparison of APTIMA Trichomonas vaginalis transcription-mediated amplification to wet mount microscopy, culture, and polymerase chain reaction for diagnosis of trichomoniasis in men and women". Am. J. Obstet. Gynecol. 200 (2): 188.e1–7. doi:10.1016/j.ajog.2008.10.005. PMID 19185101.
  21. Ginocchio C, Chapin K (2012). "Prevalence of Trichomonas vaginalis and coinfection with Chlamydia trachomatis and Neisseria gonorrhoeae in the United States as determined by the Aptima Trichomonas vaginalis nucleic acid amplification assay". J Clin Microbiol. 50 (8): 2601–2608. doi:10.1128/JCM.00748-12. PMC 3421522. PMID 22622447.
  22. Vaginitis/Trichomoniasis :Reduce your risk Archived 2008-03-16 at the Wayback Machine, American Social Health Association. Retrieved March 12, 2008.
  23. Rob, Lukáš; Martan, Alois; Citterbart, Karel; et al. (2008). Gynekologie (in Czech) (2nd ed.). Prague: Galen. p. 136. ISBN 978-80-7262-501-7.
  24. Munson E (2014). "Point: new trichs for "old" dogs: prospects for expansion of Trichomonas vaginalis screening". Clin. Chem. 60 (1): 151–4. doi:10.1373/clinchem.2013.210021. PMID 24043491.
  25. Wendel KA, Workowski KA (2007). "Trichomoniasis: challenges to appropriate management". Clin Infect Dis. 44 (Suppl 3): S123–S129. doi:10.1086/511425. PMID 17342665.
  26. Workowski KA, Berman S (December 2010). "Sexually transmitted diseases treatment guidelines, 2010". MMWR Recomm Rep. 59 (RR-12): 1–110. PMID 21160459.
  27. Smith LV, Sorvillo F, Kuo T (2013). "Implications of Trichomonas vaginalis nucleic acid amplification testing on medical training and practice". J Clin Microbiol. 51 (5): 1650. doi:10.1128/JCM.00188-13. PMC 3647919. PMID 23592856.
  28. Desai, Monica; Woodhall, Sarah C; Nardone, Anthony; Burns, Fiona; Mercey, Danielle; Gilson, Richard (2015). "Active recall to increase HIV and STI testing: a systematic review". Sexually Transmitted Infections. 91 (5): sextrans–2014–051930. doi:10.1136/sextrans-2014-051930. ISSN 1368-4973. PMID 25759476: Access provided by the University of Pittsburgh Library System
  29. Klebanoff, Mark A.; Carey, J. Christopher; Hauth, John C.; Hillier, Sharon L.; Nugent, Robert P.; Thom, Elizabeth A.; Ernest, J.M.; Heine, R. Phillip; Wapner, Ronald J. (2001-08-16). "Failure of Metronidazole to Prevent Preterm Delivery among Pregnant Women with Asymptomatic Trichomonas vaginalis Infection". New England Journal of Medicine. 345 (7): 487–493. doi:10.1056/NEJMoa003329. ISSN 0028-4793. PMID 11519502.
  30. McGregor, James A.; French, Janice I.; Parker, Ruth; Draper, Deborah; Patterson, Elisa; Jones, Ward; Thorsgard, Kyja; McFee, John (1995). "Prevention of premature birth by screening and treatment for common genital tract infections: Results of a prospective controlled evaluation". American Journal of Obstetrics and Gynecology. 173 (1): 157–167. doi:10.1016/0002-9378(95)90184-1.
  31. Workowski, Kimberly A.; Bolan, Gail A. (2015-06-05). "Sexually transmitted diseases treatment guidelines, 2015". MMWR. Recommendations and Reports: Morbidity and Mortality Weekly Report. Recommendations and Reports / Centers for Disease Control. 64 (RR-03): 1–137. ISSN 1545-8601. PMC 5885289. PMID 26042815.
  32. Vaginitis/Trichomoniasis :Treatment for trichomoniasis Archived 2008-04-01 at the Wayback Machine, American Social Health Association. Retrieved March 12, 2008.
  33. Cudmore SL, Delgaty KL, Hayward-McClelland SF, Petrin DP, Garber GE (October 2004). "Treatment of infections caused by metronidazole-resistant Trichomonas vaginalis". Clin. Microbiol. Rev. 17 (4): 783–93, table of contents. doi:10.1128/CMR.17.4.783-793.2004. PMC 523556. PMID 15489348.
  34. Niccolai LM, Kopicko JJ, Kassie A, Petros H, Clark RA, Kissinger P (2000). "Incidence and predictors of reinfection with Trichomonas vaginalis in HIV-infected women". Sex Transm Dis. 27 (5): 284–288. doi:10.1097/00007435-200005000-00009.
  35. Kissinger, Patricia; Mena, Leandro; Levison, Judy; Clark, Rebecca A; Gatski, Megan; Henderson, Harold; Schmidt, Norine; Rosenthal, Susan L; Myers, Leann (2010). "A Randomized Treatment Trial: Single Versus 7-Day Dose of Metronidazole for The Treatment of Trichomonas Vaginalis Among HIV-Infected Women". JAIDS Journal of Acquired Immune Deficiency Syndromes. 55 (5): 565–571. doi:10.1097/qai.0b013e3181eda955. PMC 3058179. PMID 21423852.
  36. Petrin D, Delgaty K, Bhatt R, Garber G (1998). "Clinical and Microbiological Aspects of Trichomonas vaginalis". Clinical Microbiology Reviews. 11 (2): 300–317. doi:10.1128/CMR.11.2.300. PMC 106834. PMID 9564565.
  37. Global Burden of Disease Study 2013, Collaborators (22 August 2015). "Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013". Lancet. 386 (9995): 743–800. doi:10.1016/s0140-6736(15)60692-4. PMC 4561509. PMID 26063472.
  38. Vos, T (Dec 15, 2012). "Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010". Lancet. 380 (9859): 2163–96. doi:10.1016/S0140-6736(12)61729-2. PMC 6350784. PMID 23245607.
  39. Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, and TB. Division of STD Prevention. Trichomoniasis - CDC Fact Sheet. 2012.
  40. Satterwhite CL, Torrone E, Meites E, et al. (2013). "Sexually transmitted infections among US women and men: prevalence and incidence estimates, 2008". Sex Transm Dis. 40 (3): 187–93. doi:10.1097/OLQ.0b013e318286bb53. PMID 23403598.
  41. Sutton M, Sternberg M, Koumans EH, McQuillan G, Berman S, Markowitz L (November 2007). "The prevalence of Trichomonas vaginalis infection among reproductive-age women in the United States, 2001-2004". Clin. Infect. Dis. 45 (10): 1319–26. doi:10.1086/522532. PMID 17968828.
  42. Rogers SM, Turner CF, Hobbs M, et al. (2014). "Epidemiology of undiagnosed trichomoniasis in a probability sample of urban young adults". PLOS ONE. 9 (3): e90548. doi:10.1371/journal.pone.0090548. PMC 3953116. PMID 24626058.
  43. Javanbakht M, Stirland A, Stahlman S, et al. (2013). "Prevalence and Factors Associated With Trichomonas vaginalis Infection Among High-Risk Women in Los Angeles". Sex Transm Dis. 40 (10): 804–807. doi:10.1097/OLQ.0000000000000026. PMC 4188531. PMID 24275733.
  44. Helms DJ, Mosure DJ, Metcalf CA, Douglas JM, Malotte CK, Paul SM, Peterman TA (May 2008). "Risk factors for prevalent and incident Trichomonas vaginalis among women attending three sexually transmitted disease clinics". Sex Transm Dis. 35 (5): 484–8. CiteSeerX doi:10.1097/OLQ.0b013e3181644b9c. PMID 18360314.
  45. Swartzendruber A, Sales JM, Brown JL, Diclemente RJ, Rose ES (2014). "Correlates of incident Trichomonas vaginalis infections among African American female adolescents". Sex Transm Dis. 41 (4): 240–5. doi:10.1097/OLQ.0000000000000094. PMC 4313569. PMID 24622635.
  46. Muzny CA, Rivers CA, Austin EL, Schwebke JR (September 2013). "Trichomonas vaginalis infection among women receiving gynaecological care at an Alabama HIV Clinic". Sex Transm Infect. 89 (6): 514–8. doi:10.1136/sextrans-2012-050889. PMID 23449600.
  47. Munson E, Kramme T, Napierala M, Munson KL, Miller C, Hryciuk JE (2012). "Female epidemiology of transcription-mediated amplification-based Trichomonas vaginalis detection in a metropolitan setting with a high prevalence of sexually transmitted infection". J Clin Microbiol. 50 (12): 3927–31. doi:10.1128/JCM.02078-12. PMC 3503002. PMID 23015673.
  48. Freeman AH, Katz KA, Pandori MW, Rauch LM, Kohn RP, Liska S, Bernstein KT, Klausner JD (March 2010). "Prevalence and correlates of Trichomonas vaginalis among incarcerated persons assessed using a highly sensitive molecular assay". Sex Transm Dis. 37 (3): 165–8. doi:10.1097/OLQ.0b013e3181bcd3fc. PMID 20023598.
  49. Nijhawan AE, DeLong AK, Celentano DD, et al. (2011). "The Association Between Trichomonas Infection and Incarceration in HIV-Seropositive and At-Risk HIV-Seronegative Women". Sex Transm Dis. 38 (12): 1094–1100. doi:10.1097/OLQ.0b013e31822ea147. PMC 3767476. PMID 22082718.
External resources
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.