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A 17-year-old teen presents with vaginal itching, odor, and discharge for several weeks. She has one partner who is asymptomatic. Speculum examination shows a cervix (Figure 86-1) with a copious foamy white discharge with a fishy odor. Wet mount shows trichomonads swimming in saline (Figures 86-2 and 86-3). The trichomonads are larger than white blood cells (WBCs) and have visible flagella and movement. She is diagnosed with trichomoniasis and treated with 2 g of metronidazole in a single dose. The patient is tested for other sexually transmitted diseases (STDs) and her partner is treated with the same regimen.


Speculum examination showing the strawberry cervix pattern seen with Trichomonas infections. This strawberry pattern is caused by inflammation and punctate hemorrhages on the cervix. There is a scant white discharge. (Reproduced with permission from Richard P. Usatine, MD.)


Wet mount showing Trichomonas in saline under low power. There are two visible trichomonads to the right and above the tip of the pointer. The largest cells are vaginal epithelial cells with visible nuclei. (Reproduced with permission from Richard P. Usatine, MD.)


Wet mount showing Trichomonas (arrows) in saline under high power. The smaller, more granular cells are white blood cells. (Reproduced with permission from Richard P. Usatine, MD.)


Trichomonas vaginitis is a local infection caused by the protozoan Trichomonas vaginalis that is associated with vaginal discharge and irritation. The patient often has an itch and an odor along with the discharge but may be asymptomatic.


Trichomoniasis, trich, tricky monkeys.


  • Trichomoniasis is the most prevalent nonviral sexually transmitted infection in the United States, affecting an estimated 3.7 million persons.1

  • The worldwide prevalence of trichomoniasis is estimated to be 180 million cases per year; these cases account for 10% to 25% of all vaginal infections.2

  • Cross-sectional data from the 2003–2004 U.S. National Health and Nutrition Examination Survey (NHANES) shows 3% of female adolescents (aged 14 to 19 years) had laboratory evidence of infection with T. vaginalis.3


  • Trichomonas infection is caused by the unicellular protozoan T. vaginalis.4

  • The majority of men (90%) infected with T. vaginalis are asymptomatic, but many women (50%) report symptoms.5

  • The infection is predominantly transmitted via sexual contact. The organism can survive up to 48 hours at 10°C (50°F) outside the body, making transmission from shared undergarments or from infected hot spas possible although extremely unlikely.

  • Trichomonas infection is associated ...

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