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Source: KnodelLC. Sexually Transmitted Diseases. In: DiPiro, JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM. Pharmacotherapy: A Pathophysiologic Approach. 8th ed. Accessed July 16, 2012.

  • Infection of genital and urinary tract

  • Caused by Trichomonas vaginalis, flagellated, motile protozoan.
    • Mostly transmitted by sexual contact
    • Infection by nonsexual contact possible because T.vaginalis survives up to 45 minutes on moist surfaces.

  • Trichomonads isolated from vagina, urethra, and paraurethral ducts and glands in women
  • Infection in extragenital sites may be source for reinfection.
    • Reinfection more common when local therapy used alone.

  • Co-infection with other sexually transmitted infections (STIs), e.g., gonorrhea, is common.

  • Mutually monogamous sexual relationship between uninfected partners
  • Barrier contraceptive methods

  • Unprotected sex
  • Number of sexual partners
  • Sexual preference
  • Age: Two-thirds of STIs occur in persons in teens and twenties.

  • Typical presentation of trichomoniasis in men and women in Table 1.

Table 1. Presentation of Trichomonas Infections

Signs and Symptoms

Means of Confirmation and Diagnosis

  • Simplest and most reliable means of diagnosis: wet-mount examination of vaginal discharge.
    • Trichomoniasis confirmed if characteristic pear-shaped, flagellating organisms observed.
  • Newer diagnostic tests such as monoclonal antibody or DNA probe techniques, as well as polymerase chain reaction (PCR) tests, highly sensitive and specific.

Laboratory Tests

  • Wet-mount examination of vaginal discharge (60–80% sensitivity)
    • Lower sensitivity in men
  • Culture
    • Not useful in rapid diagnosis because at least 48 hours needed for growth.
    • Useful in men.
  • Newer diagnostic tests:
    • Monoclonal antibody or DNA probe techniques
    • PCR tests

Differential Diagnosis

  • Bacterial vaginosis

  • Achieve maximal cure rates.
  • Prevent relapse.

  • Metronidazole and tinidazole only antimicrobial agents available in United States consistently effective in T. vaginalis infections.
  • To achieve maximal cure rates and prevent relapse with single 2-g ...

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