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.
^ Jump up to: a b Ginocchio CC, Chapin K, Smith JS, Aslanzadeh J, Snook J, Hill CS, Gaydos CA (August 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". Journal of Clinical Microbiology. 50 (8): 2601–8. doi:10.1128/JCM.00748-12. PMC 3421522. PMID 22622447.
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 advent of new, highly specific and sensitive trichomoniasis tests present opportunities for new screening protocols for both men and women. 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.