Trichomoniasis (Trich)

Photo of trichomoniasis courtesy of the CDC
Photo of trichomoniasis courtesy of the CDC

Trichomoniasis (trich) is a parasitic infection of the genital area. It has only minor (and often no) symptoms, and can only be diagnosed with a blood test or other bodily fluid sampling. While trich itself is a relatively benign infection, it has some serious complications.


Trich is transmitted through PiV intercourse and (more rarely) vaginal-to-vaginal contact. Based on the nature of the parasite and the way it is transmitted, I believe it might be possible to be transmitted through penis-to-penis.

Prevention basically comes down to not having sex with someone who is infected (but chances of knowing if you are infected are slip unless you get tested regularly), or using condoms/other barrier method which covers majority of genital area.


Trich is treated with a single does of antibiotics. Reinfection within 3 months is very common. Reinfection occurs when you get treated but your sexual partners (or their sexual partners) do not. If someone in your sexual network refuses or is unable to seek treatment, then your entire network can be reinfected within a year. 


Trich rarely has symptoms, and when it does the symptoms are mild. Over two-thirds of infected people don’t have symptoms.

Symptoms for people with a penis include:

  • Irritation inside the penis
  • Mild discharge
  • Slight burning after urination or ejaculation

Symptoms for people with a vagina include:

  • Greenish-yellow, frothy vaginal discharge with a strong odor
  • Painful urination
  • Vaginal itching and irritation
  • Discomfort during intercourse
  • Lower abdominal pain (rare)


Trich has two common (and serious) complications. In a pregnant person it increases the chance of premature birth.

It increases everyone’s chance of getting HIV. The inflammation and irritation of tissues make it much easier for HIV to enter the body.

Learn more about Safer Sex for the Non-Monogamous