Trichomoniasis

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Trichomoniasis

Topic Overview

What is trichomoniasis?

Trichomoniasis is an infection with a one-cell parasite spread by sexual contact (sexually transmitted infection, or STI). It is sometimes called a Trichomonas infection or trich (say "trick").

Both men and women can get a trich infection, but it is more common in women. Trich in pregnant women can cause problems with the pregnancy.

What causes trich?

Trich is caused by a one-cell parasite.

What are the symptoms?

Many women and most men do not have any symptoms of trich. But when you do have symptoms, they usually start within 1 week after you were infected.

In women, symptoms include:

  • Changes in your vaginal discharge. You may notice a colour or odour that is not normal.
  • Vaginal itching.
  • Pain during urination or sex.

In men, symptoms include:

  • An abnormal discharge from the penis.
  • Irritation of the tip of the penis.
  • A burning feeling when you urinate.

The time from contact with the trich parasite until you get symptoms can range from 5 to 28 days.4 This is called the incubation period. You can spread trich to others during this time and until you finish the prescribed medicine. You should avoid all sexual contact until you finish taking your medicine and the symptoms are gone.

How is trich diagnosed?

Your doctor can tell if you have trich by asking about your past health and doing a physical examination. He or she may order lab tests to find the parasite that causes trich. In women, the parasite may sometimes be found during a routine Pap test. This test is done as part of a regular pelvic examination.

How is it treated?

Your doctor will prescribe medicine called metronidazole to treat trich. This medicine kills the parasite that causes the infection. The medicine is usually taken by mouth as pills, tablets, or capsules. Medicine given in the vagina will not cure trich.

It is important to treat trich. Treatment can:

  • Kill the parasite and get rid of the infection and the symptoms.
  • Prevent you from spreading trich to others. Make sure that your sex partner(s) will be treated at the same time that you get treatment so that you don't get infected again. Avoid all sexual contact until you finish taking the medicine and until your symptoms are gone.
  • Reduce the risk of pelvic infections. These may lead to women not being able to get pregnant (infertility). Trich can also lead to infertility in men.
  • Reduce the risk of infection after any pelvic surgery.
  • Reduce the risk of getting other STIs, especially HIV.

Trich during pregnancy raises the risk of premature rupture of membranes (PROM) and premature delivery. Treating the infection does not appear to reduce this risk.9 If you are pregnant and have trich, talk to your doctor about the pros and cons of treatment.

How is trich spread, and how can it be prevented?

Trich is spread when a person has unprotected sex with an infected partner. Some people carry the parasite that causes trich, but they do not have symptoms. So it is important to practice safe sex to prevent getting trich. Using a condom each time you have sex may reduce your chance of getting an STI.

In rare cases, it may be possible to get trich from contact with personal items, such as a wet towel, that a person with trich has just used. The trich parasite cannot live on objects for long, so it is not usually spread this way.

Trich may be spread from a mother to her baby during a vaginal delivery, but this is also rare.

Symptoms of a trich infection in young children may be a sign of sexual abuse. They need to be checked by a doctor.

Frequently Asked Questions

Learning about trichomoniasis:

Being diagnosed:

Getting treatment:

Ongoing concerns:

Cause

Trichomoniasis (trich) is caused by a tiny parasite (a one-celled protozoan) that most commonly is sexually transmitted from an infected person.

In women, trich organisms usually infect the vagina, urethra, cervix, bladder, and glands in the genital area, such as Bartholin's and Skene's glands. See a picture of the female reproductive system.

In men, infections develop in the urethra or under the foreskin of an uncircumcised penis. See a picture of the male reproductive system.

Symptoms

Up to 50% of women and men infected with trichomoniasis (trich) do not have symptoms.6 If symptoms develop, they usually appear within 1 week of being infected. But symptoms can develop months later.

In women

Symptoms may be worse during pregnancy or right before or after a menstrual period. If symptoms develop, they may include:

  • Large amounts of pale yellow or grey-green, sometimes foamy discharge from the vagina.
  • Vaginal itching or irritation.
  • Abnormal musty or fishy odour.
  • Pain with sexual intercourse even if you use a lubricant such as K-Y Jelly or Astroglide.
  • Patchy red areas on the genitals or on the cervix (strawberry cervix).
  • Painful urination (dysuria) or frequent urination.
  • Discomfort in the lower abdomen. This is not a common symptom of trich and may mean another problem is present.

In men

Men rarely have symptoms but still need treatment. If symptoms are present, they may include:

  • Abnormal discharge from the penis.
  • A burning feeling after urination.
  • Irritation and redness of the tip of the penis.

Trich can have symptoms similar to those of other sexually transmitted infections such as gonorrhea or chlamydia.

What Happens

Trichomoniasis (trich) infection is spread by having unprotected sex with an infected partner. Many women and most men do not have any symptoms of trich. If symptoms appear, they usually start within 1 week of being infected. But it may take up to a month for symptoms to appear. In most cases, trich should be treated to prevent transmitting this STI to others and to prevent some problems that can happen if you are pregnant. You and your sex partner(s) should be treated for trich at the same time, to avoid reinfecting each other.

In rare cases, it may be possible to get trich by coming in contact with an object (such as a wet towel) that a person who has trich has just used. The trich organism cannot live on objects for long, so trich is not usually spread this way.

Trich during pregnancy raises the risk of premature rupture of membranes (PROM) and premature delivery. Treating the infection does not appear to reduce this risk.9 If you are pregnant and have trich, talk to your doctor about the pros and cons of treatment.

Trich may be transmitted from a mother to her baby during a vaginal delivery, but this is rare.

What Increases Your Risk

Those most affected by trichomoniasis (trich) are sexually active women ages 16 to 35. It is thought that 1 out of 5 women in this age group will become infected at some time.8

Behaviours that will increase your risk of getting trich include:

  • Not using condoms when having sex with a new partner or a partner who may have been exposed to a sexually transmitted infection (STI). It is possible for a partner to transmit the trich parasite without having any symptoms of the infection.
  • Having many sex partners, which increases your risk of being exposed to someone who has trich. Teenagers and young adults are at higher risk for getting trich and other STIs, because their sex partners often have had other recent partners who may carry an STI.

You can get other STIs, such as gonorrhea, chlamydia, HIV, and syphilis, at the same time you get a trich infection. If one STI is diagnosed, testing for other STIs should be done so that all infections can be treated at the same time.

Some diseases that can be spread through sexual contact, such as the human immunodeficiency virus (HIV) infection, are life-threatening. Studies show that trich infection may increase the risk of transmitting HIV infection.7 Health professionals around the world are concerned about the increased risk of trichomoniasis and HIV.

Women who have trich may also be at risk for other vaginal infections. About 20% of women with trich also have a yeast infection and many also have bacterial vaginosis.2

When To Call a Doctor

Call your doctor immediately if you:

Call your doctor for an appointment within 1 week if you:

  • Have an abnormal vaginal discharge.
  • Have unusual vaginal itching.
  • Have pain during sex or urination.
  • Find out that your sex partner has been diagnosed with or treated for trichomoniasis (trich).

Watchful waiting

Watchful waiting is a period of time during which you and your doctor observe your symptoms or condition without using medical treatment. Watchful waiting is not appropriate if you think you have trichomoniasis (trich). In most cases, trich should be treated to prevent transmitting this sexually transmitted infection to others and to prevent some problems that can happen if you are pregnant.

Note: Trich during pregnancy raises the risk of premature rupture of membranes (PROM) and premature delivery. Treating the infection does not appear to reduce this risk.9 If you are pregnant and have trich, talk to your doctor about the pros and cons of treatment.

Who to see

Your family doctor, gynecologist, general practitioner, or nurse practitioner can diagnose and treat a trichomoniasis (trich) infection.

To prepare for your appointment, see the topic Making the Most of Your Appointment.

Examinations and Tests

Trichomoniasis (trich) is diagnosed by:

  • Your medical history, which will include questions about your sexual history and practices.
  • A physical examination.
    • For women, this will include a visual examination of the genitals, vagina, or cervix to detect patchy red spots that are caused by trich. Any vaginal discharge will be assessed for colour, odour, and texture. A sample of discharge is taken for a wet mount test.
    • For men, this will include a visual examination of the penis and a sample of discharge from the urethra.
  • Tests to identify the trich organism.
    • The most common test in women is a wet mount, a microscopic evaluation of fluid from the vagina. This test identifies trich 60% to 70% of the time.3
    • Other tests available but less commonly used include:
      • Culture. A culture identifies trich over 90% of the time and is especially useful for men.
      • Antigen detection test (immunochromatographic strip test) that detects trich over 83% of the time.10
      • DNA probe test, which detects genetic material (DNA) of the trich parasite.

People can get other sexually transmitted infections (STIs) such as gonorrhea or syphilis at the same time they get a trich infection. If one STI is diagnosed, you will likely be tested for other STIs so that all infections can be treated at the same time.

In women, the trich parasite may also be identified by a routine Pap test done as part of a regular gynecologic examination. Expert opinions vary on the accuracy of a Pap test for diagnosing trich. But if a Pap test shows trich, your doctor will probably talk to you about treatment or maybe other tests.

Treatment Overview

Trichomoniasis (trich) is treated with an oral antiprotozoal medicine, such as metronidazole. The medicine is taken either as a single dose or as multiple doses. The cure rate in treating trich using metronidazole is 90% to 95%. 3

Sex partner(s) should be treated at the same time you are being treated. This increases the cure rate and reduces the possibility of further transmission or reinfection. Sexual intercourse should be avoided during treatment until symptoms have gone away and until partners have been treated. It is best to avoid sex for 1 week after treatment with a single dose of metronidazole. Male partners may not have symptoms but still need treatment.

People who are infected with HIV receive the same treatment for trich as those who are HIV-negative.

Trichomoniasis in pregnant women

Trichomoniasis during pregnancy raises the risk of premature rupture of membranes (PROM) and premature delivery. Treating the infection does not appear to reduce this risk.9 If you are pregnant and have trichomoniasis, talk to your doctor about the pros and cons of treatment.

Vaginal suppositories and creams are not effective in curing trich, but they may reduce discomfort and swelling in the genital area.

Follow-up

  • No follow-up is needed if symptoms go away. It is possible to get trich again, so it is important to take measures to reduce your risk for trich and other sexually transmitted infections (STIs).
  • If symptoms do not go away, you may need to take the medicine again.
  • If treatment fails after this and you have not been reinfected, further testing may be done to find out the cause of your symptoms. It is possible to have a strain of trich that is resistant to antiprotozoal medicines. If this is the case, you may need to take a large dose of metronidazole. This will usually cure the infection.1

If trich goes untreated or is not properly treated, complications can develop, such as pelvic inflammatory disease (PID) in women or conditions that contribute to infertility in men.5

What to Think About

Metronidazole vaginal suppositories or creams are not recommended, because oral metronidazole is much more effective. Vaginal medicines cure trich in less than 50% of cases.3

Metronidazole vaginal gel, which is used to treat bacterial vaginosis, is not recommended by the Public Health Agency of Canada (PHAC) for treatment of trich.1

Prevention

Take measures to reduce your risk of becoming infected with trichomoniasis (trich) or other sexually transmitted infections (STIs), such as gonorrhea, chlamydia, HIV, or syphilis. You can also reduce the risk of transmitting an STI to your sex partner(s).

Practice safe sex

Preventing an STI is easier than treating an infection after it occurs.

  • Talk with your partner about STIs before beginning a sexual relationship. Find out if he or she is at risk for an STI. Remember that it is quite possible to be infected with an STI without knowing it. It can take up to 6 months before some STIs, such as HIV, are detected in the blood.
  • Be responsible.
    • Avoid sexual contact if you have symptoms of an STI or are being treated for an STI.
    • Avoid all intimate sexual contact with anyone who has symptoms of an STI.
  • Don't have more than one sex partner at a time. Your risk of getting an STI increases if you have several sex partners at the same time.

Male condom use

Condom use may reduce the risk of becoming infected with an STI. Condoms must be put on before beginning any sexual contact. Use condoms with a new partner until you are certain he or she does not have an STI. Male or female condoms can be used. It is important that you use a condom properly to prevent the risk of trich infection. For more information, see how to use a condom.

Female condom use

Even if you are using a birth control method to prevent pregnancy, you may wish to use condoms to reduce your risk of getting an STI. Female condoms are available for women whose partners do not have or will not use a male condom. For more information, see how to use a female condom.

Home Treatment

There is no home treatment for trichomoniasis (trich). But you can lower your chances of getting trich or other sexually transmitted infections (STIs) by making careful choices about sex. For example, you can make sure to always use condoms during sex. For more information, see the topic Safe Sex.

Trich is not usually transmitted by contact with objects. But avoid using objects such as face cloths or wet towels that a person with trich may have used.

It is safe for a woman to use tampons while she has a trich infection, but it may be uncomfortable.

Avoid douching. It does not help relieve symptoms, and it can even make them worse.

Medications

Trichomoniasis (trich) is usually treated with a medicine called metronidazole. The cure rate in treating trich using metronidazole is 90% to 95%.3

Medication Choices

Antiprotozoals, such as metronidazole, are medicines that kill the tiny parasite that causes trich.

What to Think About

Trich during pregnancy raises the risk of premature rupture of membranes (PROM) and premature delivery. Treating the infection does not appear to reduce this risk.9 If you are pregnant and have trich, talk to your doctor about the pros and cons of treatment.

Metronidazole vaginal suppositories or creams are not recommended because oral metronidazole is much more effective. Vaginal medicines cure trich in less than 50% of cases.3

Metronidazole vaginal gel, which is used to treat bacterial vaginosis, is not recommended for treatment of trich.1

Surgery

Surgery is not done to treat trichomoniasis.

Other Treatment

There is no other treatment for trichomoniasis at this time.

Other Places To Get Help

Organizations

Canadian Federation for Sexual Health
1 Nicholas Street
Suite 430
Ottawa, ON  K1N 7B7
Phone: (613) 241-4474
Email: admin@cfsh.ca
Web Address: www.cfsh.ca
 

The Canadian Federation for Sexual Health, previously called Planned Parenthood Federation of Canada, is a non-government, pro-choice organization in Canada that provides services, information, and counselling exclusively on sexual and reproductive health.


Public Health Agency of Canada (PHAC)
130 Colonnade Road
A.L. 6501H
Ottawa, ON  K1A 0K9
Phone: Telephone numbers for PHAC vary by region. For your regional number, go to the listing on the PHAC website at www.phac-aspc.gc.ca/contac-eng.php.
Web Address: www.phac-aspc.gc.ca/index-eng.php
 

The Public Health Agency of Canada (formerly the Population and Public Health Branch of Health Canada) is primarily responsible for policies, programs, and systems relating to disease prevention, health promotion, disease surveillance, community action, and disease control.


sexualityandu.ca
Web Address: www.sexualityandu.ca
 

The Web site gives teens, adults, parents, teachers, and health professionals information and education on sexual health.


References

Citations

  1. Public Health Agency of Canada (2006, updated 2008). Vaginal discharge (bacterial vaginosis, vulvovaginal candidiasis, trichomoniasis). Canadian Guidelines on Sexually Transmitted Infections. Available online: http://www.phac-aspc.gc.ca/std-mts/sti-its/pdf/408vagdis-eng.pdf.
  2. Hobbs MM, et al. (2008). Trichomonas vaginalis and trichomoniasis. In KK Holmes et al., eds., Sexually Transmitted Diseases, 4th ed., pp. 771–793. New York: McGraw-Hill.
  3. U.S. Department of Health and Human Services (2006). Sexually Transmitted Diseases Treatment Guidelines, 2006 (CDC Publication Vol. 55, No. RR-11), pp. 52–54. Atlanta: U.S. Department of Health and Human Services. Also available online: http://www.cdc.gov/STD/treatment/2006/rr5511.pdf.
  4. American Academy of Pediatrics (2006). Trichomonas vaginalis infections (Trichomoniasis). In LK Pickering et al., eds., Red Book: 2009 Report of the Committee on Infectious Diseases, 28th ed., pp. 674–675. Elk Grove Village, IL: American Academy of Pediatrics.
  5. Soper D (2004). Trichomoniasis: Under control or undercontrolled? American Journal of Obstetrics and Gynecology, 190: 281–290.
  6. British Association of Sexual Health and HIV (2007). Management of Trichomonas Vaginalis Infection. Available online: http://www.bashh.org/guidelines.asp.
  7. Forna F, Gülmezoglu AM (2003). Interventions for treating trichomoniasis in women. Cochrane Database of Systematic Reviews (2).
  8. American Public Health Association (2008). Trichomoniasis. In DL Heymann, ed., Control of Communicable Diseases Manual, 19th ed., pp. 625–627. Washington, DC: American Public Health Association.
  9. American College of Obstetricians and Gynecologists (2006, reaffirmed 2008). Vaginitis. ACOG Practice Bulletin No. 72. Obstetrics and Gynecology, 107(5): 1195–1206.
  10. Huppert JS, et al. (2005). Use of an immunochromatographic assay for rapid detection of Trichomonas vaginalis in vaginal specimens. Journal of Clinical Microbiology, 43(2): 684–687.

Other Works Consulted

  • Anderson MR, et al. (2004). Evaluation of vaginal complaints. JAMA, 291(11): 1368–1379.
  • McCormack WM (2010). Trichomoniasis section of Volvovaginitis and cervicitis. In GL Mandell et al., eds., Mandell, Douglas, and Bennett's Principles and Practices of Infectious Diseases, 7th ed., vol. 1, pp. 1498–1500. Philadelphia: Churchill Livingstone Elsevier.
  • Schwebke, JR, Hook EW III (2003). High rates of trichomonas vaginalis among men attending a sexually transmitted diseases clinic: Implications for screening and urethritis management. Journal of Infectious Diseases, 188: 465–468.

Credits

By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Primary Medical Reviewer Brian D. O'Brien, MD - Internal Medicine
Specialist Medical Reviewer Jeanne Marrazzo, MD, MPH - Infectious Disease
Last Revised September 3, 2010

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.