Trichomoniasis (trich) infection is spread when you have 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 after a person is infected. But it may take up to a month for symptoms to appear. In most cases, trich should be treated to prevent transmitting this sexually transmitted infection (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.
Your 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 are gone 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.
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]
The parasite passes from an infected person to an uninfected person during sex. In women, the most commonly infected part of the body is the lower genital tract (vulva, vagina, cervix, or urethra). In men, the most commonly infected body part is the inside of the penis (urethra). During sex, the parasite usually spreads from a penis to a vagina, or from a vagina to a penis. It can also spread from a vagina to another vagina. It is not common for the parasite to infect other body parts, like the hands, mouth, or anus. It is unclear why some people with the infection get symptoms while others do not. It probably depends on factors like a person’s age and overall health. Infected people without symptoms can still pass the infection on to others.
There were about 58 million cases of trichomoniasis in 2013.[38] It is more common in women (2.7%) than males (1.4%).[39] 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.[40][41] It is estimated that 3% of the general U.S. population is infected,[21][42] and 7.5-32% of moderate-to-high risk (including incarcerated) populations.[43][44][45][46][47][48][49][50]

Your 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 are gone 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.


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]
Blood in semen is also known as hematospermia. Blood in semen can be caused by many conditions affecting the tubes that distribute semen from the testicles (seminal vesicles) or the prostate gland. Symptoms that may accompany blood in semen include blood in the urine, fever, painful urination, pain with ejaculation, tenderness, and swelling in the testes or groin area. Urinalysis, ultrasound, and MRI may be used to diagnose blood in the semen. Treatment depends upon the underlying cause of blood in the semen.
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]
If you’re pregnant, trich may make you give birth earlier than expected. Your baby may have a low birth weight, which can raise the chances of health or developmental problems. It’s rare, but your baby may also get trich as they go through the birth canal. You can get treated for trich while pregnant, so talk to your doctor about the best options for you.
For 95-97% of cases, infection is resolved after one dose of metronidazole.[26][35] 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][36]
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]
Watchful waiting is a period of time during which you and your doctor observe your symptoms or condition without using medical treatment. Watchful waiting isn't 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.
^ Vos T, et al. (GBD Study 2013 Collaborators) (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.
People who have been treated for trichomoniasis can get it again. About 1 in 5 people get infected again within 3 months after receiving treatment. To avoid getting reinfected, all sex partners should get treated with antibiotics at the same time. Wait to have sex again until everyone has been treated and any symptoms go away (usually about a week). Get checked at 3 months to make sure you have not been infected again, or sooner if your symptoms come back before then.
Use condoms. Condoms are the best way to prevent STIs when you have sex. Because a man does not need to ejaculate (come) to give or get trichomoniasis, make sure to put the condom on before the penis touches the vagina, mouth, or anus. Other methods of birth control, like birth control pills, shots, implants, or diaphragms, will not protect you from STIs. Get tested. Be sure you and your partner are tested for STIs. Talk to each other about the test results before you have sex.
×