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.
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.
Sexually transmitted diseases (STDs) are among the most common infectious diseases in the United States. STDs can be spread through any type of sexual activity involving the sex organs, the anus or mouth, or through contact with blood during sexual activity. Examples of STDs include, chancroid, chlamydia, gonorrhea, granuloma inguinale, lymphogranuloma venereum, syphilis, genital herpes, genital warts, trichomoniasis, pubic lice (crabs), and scabies. Treatment is generally with antibiotics; however, some STDs that go untreated can lead to death.