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Trichomoniasis : most common STD in female

  • April 10, 2011
  • 3 min read
Trichomoniasis : most common STD in female

Trichomomal Vaginitis is the most common vaginitis in the childbearing period.

Causative Organism and Transmission-

It is caused by a protozoan called Trichomonas vaginalis which is 20 micrometer X 10 micrometer pear shaped parasitic organism. It has 4 anterior flagellae and a spear-like protrusion at the other end . It is covered by an undulating membrane on its anterior 2/3rd. It is actively motile organism.

Predominantly transmitted by sexual contact. Urethra and prostrate of Male ( men) harbors the trichomonas and may even be transmitted via toilet articles from women-women or via examining gloves of a health personnel.

Incubation period is 3-28 days.


25% of women in reproductive age group have asymptomatic infection. When local defence mechanisms are impaired during menstruation, following illness or having sex after having a baby, the pH of vagina is raised to 5.5-6.5. Trichomonas infection can thus occur at this pH. They produce inflammatory reaction.

75% organism can be isolated from Urethra, Skene’s tubules and Bartholin’s gland .

Clinical Features-

  1. There is profuse, offensive vaginal discharge ( usually following menstruation)
  2. Itching and Irritation mild to severe around the genitalia
  3. Urinary symptoms like dysurea ( painful urination), frequency of urination can occur
  4. History of similar attacks in past may be derieved
  5. Up to one-third of infected women have no symptoms


  • The majority of infected men have no symptoms
  • Urethral discharge,Pain with urination – dysurea
  • Pain and swelling in the scrotum

On Examination-

  • Thin, froathy, greenish to yellow, offensive discharge per vaginum
  • The vulva is inflamed, Evidence of pruritis like scratch marks, abrasions, redness may be seen.
  • Per vaginal examination may be painful, red inflamed walls with punctuate hemorrhages can be seen. Similar lesions may also be seen  over the PortioVaginalis part of Cervix and may be “ Strawberry” appearance.


  • Identification is done by Hanging drop preparation. Motile organisms may be found. If negative on repeated examinations, culure should be done for confirmation.
  • Culture of the discharge collected by swabs in Kupfberg’s or Fein Whittington medium.

D/D– Gonorrhea, Candidiasis.


  1. Metronidazole is quiet effective for the treatment. 200mg TDS PO for 1 week is given. Partner should be treated at the same time and for same duration. Barrier methods of contraception should be used until cured. A second course of therapy may be required if the symptoms persist after 7 days. Upto 3 cycles in 3 months may be needed.Use of Metronidazole in Pregnancy  can cause teratogenic effects on fetus ( congenital malformations).
  2. Clotrimazole pessaries 100mg for consecutive 6 nights. It is preferred during pregnancy and lactation. It treats candidiasis as well.

More Readings at- Simplified Trichomoniasis ,Patients’s Reading

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