Trichomoniasis – Risk Factors,Cause, Morphology, Symptoms, diagnosis, Treatment, complication in pregnancy and Neonate


Trichomoniasis is defined as a genitourinary infection with the protozoan Trichomonas vaginalis, which is transmitted by unprotected sexual intercourse. It is Most common parasitic cause of STD (sexual transmitted disease). Females are more commonly affected than males


Risk Factors

  • Multiple sexual partners
  • Lower socioeconomic status
  • History of STDs
  • Lack of condom use


• Etiologic agent

– Trichomonas vaginalis

– Only protozoan that infects the genital tract


  • It is Pear shaped
  • Jerky or twitching motility on saline mount
  • Bears 5 flagella (4 anterior flagella and 1 lateral flagellum attached to undulating membrane)
  • Resides : In Females – Vagina and urethra, In Male- Urethra, seminal vesicle and prostate

Sign and symptoms

  • Ranges from an acute, severe inflammatory disease to an asymptomatic carrier state. 
  • Common signs and symptoms of acute infection is:
    • Purulent, Malodorous, Thin discharge
    • Burning sensation, 
    • Pruritus (itching)
    • Dysuria- difficulty in micturition
    • Increase frequency of micturition
    • Lower abdominal pain
    • Dyspareunia (pain during sexual intercourse)

• On colposcopy – small punctate hemorrhagic spots on vagina and cervix (strawberry cervix) seen in 2% cases only

  • In chronic case, symptoms are milder which includes pruritus and dyspareunia and less vaginal secretion.

Trichomoniasis vaginalis in Men

  • mostly asymptomatic
  • May cause up to 10% of Non-gonococcal urethritis in males
  • It is Associated with increased shedding of HIV in HIV-infected men
  • Prostatitis
  • Dysurea
  • Non purulent discharge ( fish-like odour)
  • Irritation inside the penis or slight burning after urination or ejaculation
  • Painful intercourse and inflammation of the external genitals.

Pregnancy complications

  • Premature rupture of the membranes 
  • Preterm delivery
  • Low birth weight infant.

Newborn complications

  • Infants born to trichomoniasis infected mothers may contract infection during delivery.
  •  Signs and symptoms in neonates include fever, respiratory problems, urinary tract infection, nasal discharge, and in girls, vaginal discharge may occurs


  • Routine screening for Trichomonas vaginalis in asymptomatic pregnant women is not advocated. 
  • Those Women who report symptoms  be evaluated and treated appropriately.
  • screening for Trichomonas vaginalis should be done  in all HIV-infected women, yearly and at their initial prenatal visits because Trichomonas vaginalis infection is a risk factor for vertical transmission of HIV
  • Screening is reasonable for women at increased risk of Trichomonas infection, including those with new or multiple partners or a history of sexually transmitted infections.


  • Microscopy and pH-presence of motile trichomonias on wet mount is diagnostic of infection
  • Vaginal pH- elevated (>4.5)
  • Nucleic acid amplification test(NAT)
  • Rapid antigen and DNA hybridization probes
  • Culture is the “gold standard”
  • Culture -Diamond’s medium (not widely available)
  • Cervical cytology -sensitivity of liquid-based smears for Trichomonas infection was low


• CDC-recommended regimen

Metronidazole 2 g orally in a single dose

• Alternative regimen

– Metronidazole 500 mg two times a day for 7 days

  •  Because many pregnant women have significant nausea or vomiting, some clinicians prefer metronidazole 500 mg twice daily orally for five to seven days to lessen medication induced nausea and vomiting.
  • Tinidazole should be avoided in pregnancy, especially in the first trimester.

Partner Management

• Sex partners should be treated with metronidazole.

• Patients Must be instructed to avoid sex until they and their sex partners are cured i.e when therapy has been completed.

Patient Counseling and Education

• Nature of the disease

– It May be symptomatic or asymptomatic, douching may worsen vaginal discharge, untreated trichomoniasis is associated with adverse pregnancy outcomes like premature rupture of the membrane, Preterm delivery and Low birth weight infant.

• Transmission issues

It is almost always sexually transmitted, Rarely fomites transmission, It may persist for months to years, associated with increased susceptibility to HIV infection.

Risk Reduction

The clinician should:

 • Assess patient’s potential for behavior change

 • Discuss individualized risk-reduction plans with the patient

 •Discuss prevention strategies such as sexual abstinence, monogamy, use of  condoms, and limiting the number of sex partners

• consistently and correctly  use of Latex condoms, can reduce the risk of transmission of Trichomonas vaginalis.


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