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. It is more common in women (2.7%) than males (1.4%). 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. It is estimated that 3% of the general U.S. population is infected, and 7.5-32% of moderate-to-high risk (including incarcerated) populations.
^ Kissinger P, Mena L, Levison J, Clark RA, Gatski M, Henderson H, et al. (December 2010). "A randomized treatment trial: single versus 7-day dose of metronidazole for the treatment of Trichomonas vaginalis among HIV-infected women". Journal of Acquired Immune Deficiency Syndromes. 55 (5): 565–71. doi:10.1097/qai.0b013e3181eda955. PMC 3058179. PMID 21423852.
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. 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.
^ Jump up to: a b Vos T, Allen C, Arora M, Barber RM, Bhutta ZA, Brown A, Carter A, et al. (GBD 2015 Disease and Injury Incidence and Prevalence Collaborators) (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.
Trichomoniasis (trich) is an infectious disease caused by the parasite Trichomonas vaginalis. About 70% of women and men do not have symptoms when infected. When symptoms do 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.
^ Munson E, Kramme T, Napierala M, Munson KL, Miller C, Hryciuk JE (December 2012). "Female epidemiology of transcription-mediated amplification-based Trichomonas vaginalis detection in a metropolitan setting with a high prevalence of sexually transmitted infection". Journal of Clinical Microbiology. 50 (12): 3927–31. doi:10.1128/JCM.02078-12. PMC 3503002. PMID 23015673.
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.
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.