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Trichomonas Vaginalis

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Trichomonas Vaginalis

Basics

Description

Elevated vaginal pH and increased number of WBCs on wet prep are consistent with diagnosis of trichomoniasis.

Consider referral to obstetrician/gynecologist or infectious disease specialist if symptoms persist after treatment.

Treatment is primarily outpatient.

Patients with trichomoniasis should be screened for other concurrent STIs including HIV.

1Workowski KA, Berman S Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines, 2010. MMWR Recomm Rep. 2010;59:1 " 110. [View Abstract]

1Sutton M, Sternberg M, Koumans EH. The prevalence of Trichomonas vaginalis infection among reproductive-age women in the United States, 2001 " 2004. Clin Infect Dis. 2007;45(10):1319 " 1326. [View Abstract]2Huppert JS, Batteiger BE, Braslins P. Use of an immunochromatographic assay for rapid detection of T. vaginalis in vaginal specimens. J Clin Microbiol. 2005;43:684 " 687. [View Abstract]3Andrea SB, Chapin KC. Comparison of Aptima Trichomonas vaginalis transcription-mediated amplification assay and BD affirm VPIII for detection of T. vaginalis in symptomatic women. J Clin Microbiol. 2011;49:866 " 869. [View Abstract]4Van Der Pol B, Kraft CS, Williams JA. Use of an adaptation of a commercially available PCR assay aimed at diagnosis of Chlamydia and Gonorrhea to detect T. vaginalis in urogenital specimens. J Clin Microbiol. 2006;44:366 " 373. [View Abstract]5McClelland RS, Sangare L, Hassan WM. Infection with Trichomonas vaginalis increases the risk of HIV-1 acquisition. J Infect Dis. 1007;195:698 " 702. [View Abstract]6Okun N, Gronau KA, Hannah ME. Antibiotics for bacterial vaginosis or Trichomonas vaginalis in pregnancy: a systematic review. Obstet Gynecol. 2005;105:857 " 868. [View Abstract]

Trichomonads are similar in size to and difficult to distinguish from WBCs unless they are motile.

131.01 Trichomonal vulvovaginitis

276877003 trichomonal vaginitis (disorder)

  • Trichomoniasis is the third leading cause of vaginitis in women, after bacterial vaginosis and yeast vaginitis.
  • Trichomonas vaginalis is the causative organism:ProtozoanMotile organism with 4 flagellaTransmitted via sexual contact
  • Trichomoniasis is the most common sexually transmitted infection (STI) aside from human papillomavirus (HPV). More common than Chlamydia trachomatis or Neisseria gonorrhoeae.May receive less attention because it is not a reportable disease
  • Protozoan
  • Motile organism with 4 flagella
  • Transmitted via sexual contact
  • May receive less attention because it is not a reportable disease

Epidemiology

  • Approximately 120 million women worldwide become infected each year.
  • Estimated 3 " “5 million new cases per year in the US
  • Affects 180 million women worldwide
  • Accounts for up to 35% of vaginal infections in women
  • Among young adults in the US, higher prevalence among African American women

Risk Factors

  • Unprotected intercourse
  • Multiple sexual partners
  • Intrauterine devices
  • Tobacco use
  • Other STIs

General Prevention

Etiology

  • Transmission of T. vaginalis via sexual contact
  • Trichomonas can be transmitted via man-to-woman and woman-to-woman contact.Organism identified in 30 " “40% of male sexual partners of heterosexual womenCarriage in men is self-limited and transient
  • Incubation period of 5 " “10 days in general, but can range from 1 to 28 days
  • Organism identified in 30 " “40% of male sexual partners of heterosexual women
  • Carriage in men is self-limited and transient

Associated Conditions

Diagnosis

History

  • Unprotected sexual intercourse
  • Copious, foul-smelling vaginal discharge (70%)Color of discharge ranging from white to yellow-green
  • Pruritus
  • Postcoital bleeding
  • Vaginal irritation
  • Dysuria
  • Dyspareunia
  • Abdominal pain in 10%
  • Color of discharge ranging from white to yellow-green

Physical Exam

  • Vulvar and vaginal erythema
  • Frothy white or yellow-green discharge (seen in 10 " “30% of cases)
  • "Strawberry "  cervix (2% of cases)Erythematous cervix with punctuate hemorrhages
  • Focal tenderness/masses usually absent but can occurMild cervical motion tendernessMild lower abdominal discomfort
  • Erythematous cervix with punctuate hemorrhages
  • Mild cervical motion tenderness
  • Mild lower abdominal discomfort

Tests

  • Vaginal pH >4.5 (normal = 4.5)
  • Light microscopy (see Photo):45 " “60% sensitivity>95% specificity when motile trichomonads visualizedOrganisms remain motile for up to 10 " “20 minutes after sample collection.
  • DNA probe (AFFIRM VP III):>95% sensitivity, >95% specificityCommercially available probe which simultaneously detects the presence of Candida species, Gardnerella vaginalis, and T. vaginalis from single vaginal swabResults within 45 minutesMust be performed by laboratory
  • Immunochromatography (OSOM Trichomonas Rapid Test):Detects Trichomonas antigenDiagnosis within 10 minutesSensitivity 88.3% and specificity 98.8%Performed in provider office
  • Transcription-mediated amplification to detect N. gonorrhoeae, C. trachomatis, and T. vaginalis on single genital swab or urine specimenNot commercially available in the USSensitivity 74 " “100% and specificity 87 " “100%Performed in provider office
  • Polymerase chain reaction (PCR):88 " “97% sensitivity, 98 " “99% specificityEmerging as accurate diagnostic methodNot commercially available in the US
  • PAP smear:Trichomonads can be found incidentally on routine conventional and liquid-based PAP smear.Sensitivity ranges from 61%, specificity up to 99.9% in some studies for liquid-based PAP.
  • Urinalysis:Trichomonads often found incidentally on urinalysis
  • Culture:Modified Diamond 's medium is gold standard.95% sensitivity, >95% specificityDiagnosis within 2 " “7 daysSome systems designed for specimen collection and culture in provider 's officeCulture generally not used because of length of time for diagnosis and lack of availability of culture medium
  • STI screening should be performed if Trichomonas identified:HIVChlamydiaGonorrheaSyphilisHepatitis B and C
  • 45 " “60% sensitivity
  • >95% specificity when motile trichomonads visualizedOrganisms remain motile for up to 10 " “20 minutes after sample collection.
  • Organisms remain motile for up to 10 " “20 minutes after sample collection.
  • >95% sensitivity, >95% specificity
  • Commercially available probe which simultaneously detects the presence of Candida species, Gardnerella vaginalis, and T. vaginalis from single vaginal swab
  • Results within 45 minutes
  • Must be performed by laboratory
  • Detects Trichomonas antigen
  • Diagnosis within 10 minutes
  • Sensitivity 88.3% and specificity 98.8%
  • Performed in provider office
  • Not commercially available in the US
  • Sensitivity 74 " “100% and specificity 87 " “100%
  • Performed in provider office
  • 88 " “97% sensitivity, 98 " “99% specificity
  • Emerging as accurate diagnostic method
  • Not commercially available in the US
  • Trichomonads can be found incidentally on routine conventional and liquid-based PAP smear.
  • Sensitivity ranges from 61%, specificity up to 99.9% in some studies for liquid-based PAP.
  • Trichomonads often found incidentally on urinalysis
  • Modified Diamond 's medium is gold standard.95% sensitivity, >95% specificityDiagnosis within 2 " “7 daysSome systems designed for specimen collection and culture in provider 's officeCulture generally not used because of length of time for diagnosis and lack of availability of culture medium
  • 95% sensitivity, >95% specificity
  • Diagnosis within 2 " “7 days
  • Some systems designed for specimen collection and culture in provider 's office
  • Culture generally not used because of length of time for diagnosis and lack of availability of culture medium
  • HIV
  • Chlamydia
  • Gonorrhea
  • Syphilis
  • Hepatitis B and C
  • Samples for pH, microscopy, DNA probe, and culture should be obtained from the posterior fornix or vaginal wall.
  • Obtaining a sample from cervical os may reveal normal cervical mucous.
  • Light microscopy:Presence of motile organisms and increased number of WBCs suggestive of TrichomonasWBCs and T. vaginalis are similar in size and shape, but only trichomonads are motile.Wet preparation slidePlace thin layer of discharge on glass slideAdd 1 drop of normal saline to slide and view under low powerOrganisms not visualized by light microscopy in up to 50% of women with culture-confirmed infectionLikelihood of visualizing organisms may be increased by:Immediately adding normal saline to slide and viewing slides. Increasing time interval between collection and examination decreases visualization of motile trichomonads.Warming slideDecreasing intensity of substage lighting on microscope
  • Negative result does not rule out infection.
  • Presence of motile organisms and increased number of WBCs suggestive of Trichomonas
  • WBCs and T. vaginalis are similar in size and shape, but only trichomonads are motile.
  • Wet preparation slidePlace thin layer of discharge on glass slideAdd 1 drop of normal saline to slide and view under low power
  • Organisms not visualized by light microscopy in up to 50% of women with culture-confirmed infection
  • Likelihood of visualizing organisms may be increased by:Immediately adding normal saline to slide and viewing slides. Increasing time interval between collection and examination decreases visualization of motile trichomonads.Warming slideDecreasing intensity of substage lighting on microscope
  • Place thin layer of discharge on glass slide
  • Add 1 drop of normal saline to slide and view under low power
  • Immediately adding normal saline to slide and viewing slides. Increasing time interval between collection and examination decreases visualization of motile trichomonads.
  • Warming slide
  • Decreasing intensity of substage lighting on microscope

Differential Diagnosis

  • Bacterial vaginosis
  • Vulvovaginal candidiasis
  • Atrophic vaginitis
  • Cervicitis

Treatment

Medication

  • Metronidazole: 500 mg PO b.i.d. ƒ — 7 days
  • Cure rate:Single-dose regimen = 82 " “88%7-day regimen = 85 " “90%
  • Better compliance with single-dose regimen
  • Common side effects: Nausea, vomiting, metallic taste, and GI upset. Occur less with 7-day regimen.
  • Patients should be cautioned to avoid alcohol.
  • Single-dose regimen = 82 " “88%
  • 7-day regimen = 85 " “90%
  • Partners should also be treated.
  • Patients should avoid sexual intercourse until both they and partners are treated successfully and are asymptomatic, which usually occurs within 1 week.

Additional Treatment

  • All nonpregnant women should be treated, even if asymptomatic (1)[A].
  • Abstain from sexual intercourse until both patient and her partner treated and asymptomatic
  • Encourage safe-sex practices

In-Patient Considerations

Ongoing Care

Follow-Up Recommendations

Complications

  • Antibiotic resistance:Resistance rate according to Centers for Disease Control and Prevention (CDC): 2.5 " “5%Regimens for resistance organisms:First failure: Retreat with metronidazole 500 mg b.i.d. ƒ — 7 days (1)[B]Second failure: Metronidazole 2 g PO daily ƒ — 5 days or tinidazole 500 mg PO four times daily with 500 mg intravaginally twice daily ƒ — 14 days or paromomycin 5 g/day intravaginally for 14 days (1)[C]If above regimens are not effective, the CDC is available for consultation (www.cdc.gov/std).
  • Recurrence:Rate of recurrence can be decreased by:Treating sexual partnerAdvising patients to avoid sexual intercourse until both partners are treated successfullyParticipating in safe-sex practices
  • High prevalence of coinfection with other STIs:Increased risk of transmission of HIVIncreases susceptibility of uninfected individualsIncreases infectivity of infected individuals
  • Complications in pregnancy (see below)
  • Infertility:Women with prior Trichomonas infection are at increased risk of tubal infertility.Risk of infertility may increase with number of episodes of trichomoniasis.May be secondary to concomitant Chlamydia or Gonorrhea infectionTrichomonas may alter sperm motility and viability in men.
  • Pelvic inflammatory disease (PID):Higher rate of PID among women with trichomoniasis than uninfected womenAmong women colonized with Chlamydia, higher rate of symptomatic disease in those who were also infected with Trichomonas
  • Cervical intraepithelial neoplasia (CIN):Trichomonas infection has been associated with higher risks of subsequent CIN.Unclear if Trichomonas alone or the coinfection of Trichomonas and HPV contributes to the development of CIN
  • Postoperative infection:Women with trichomoniasis more likely to develop vaginal cuff cellulitis or abscess.
  • Resistance rate according to Centers for Disease Control and Prevention (CDC): 2.5 " “5%
  • Regimens for resistance organisms:First failure: Retreat with metronidazole 500 mg b.i.d. ƒ — 7 days (1)[B]Second failure: Metronidazole 2 g PO daily ƒ — 5 days or tinidazole 500 mg PO four times daily with 500 mg intravaginally twice daily ƒ — 14 days or paromomycin 5 g/day intravaginally for 14 days (1)[C]
  • If above regimens are not effective, the CDC is available for consultation (www.cdc.gov/std).
  • First failure: Retreat with metronidazole 500 mg b.i.d. ƒ — 7 days (1)[B]
  • Second failure: Metronidazole 2 g PO daily ƒ — 5 days or tinidazole 500 mg PO four times daily with 500 mg intravaginally twice daily ƒ — 14 days or paromomycin 5 g/day intravaginally for 14 days (1)[C]
  • Rate of recurrence can be decreased by:Treating sexual partnerAdvising patients to avoid sexual intercourse until both partners are treated successfullyParticipating in safe-sex practices
  • Treating sexual partner
  • Advising patients to avoid sexual intercourse until both partners are treated successfully
  • Participating in safe-sex practices
  • Increased risk of transmission of HIV
  • Increases susceptibility of uninfected individuals
  • Increases infectivity of infected individuals
  • Women with prior Trichomonas infection are at increased risk of tubal infertility.Risk of infertility may increase with number of episodes of trichomoniasis.May be secondary to concomitant Chlamydia or Gonorrhea infection
  • Trichomonas may alter sperm motility and viability in men.
  • Risk of infertility may increase with number of episodes of trichomoniasis.
  • May be secondary to concomitant Chlamydia or Gonorrhea infection
  • Higher rate of PID among women with trichomoniasis than uninfected women
  • Among women colonized with Chlamydia, higher rate of symptomatic disease in those who were also infected with Trichomonas
  • Trichomonas infection has been associated with higher risks of subsequent CIN.
  • Unclear if Trichomonas alone or the coinfection of Trichomonas and HPV contributes to the development of CIN
  • Women with trichomoniasis more likely to develop vaginal cuff cellulitis or abscess.
  • Trichomonas infection is associated with:Premature ruptures of membranesPreterm laborLow birth weight
  • Metronidazole crosses placenta, but no evidence that its use in first trimester causes birth defects
  • The CDC recommends treating symptomatic pregnant women with a single 2 g dose of metronidazole (1)[A], but does not recommend treating asymptomatic pregnant women (1)[C].Treatment of asymptomatic infection has not been shown to prevent associated risks in pregnancy.Treatment may, in fact, increase rate of preterm birth.
  • Lactating women (1)[A]:Women should withhold breastfeeding during treatment with metronidazole and for 12 " “24 hours after last dose to reduce the exposure of infant to metronidazole.With tinidazole, interruption of breastfeeding is recommended during treatment and for 3 days after the last dose.
  • Premature ruptures of membranes
  • Preterm labor
  • Low birth weight
  • Treatment of asymptomatic infection has not been shown to prevent associated risks in pregnancy.
  • Treatment may, in fact, increase rate of preterm birth.
  • Women should withhold breastfeeding during treatment with metronidazole and for 12 " “24 hours after last dose to reduce the exposure of infant to metronidazole.
  • With tinidazole, interruption of breastfeeding is recommended during treatment and for 3 days after the last dose.

References

Additional Reading

Additional-Reading-See-Also

Codes

ICD9

ICD10

SNOMED

Clinical Pearls

  • Trichomonas vaginalis infection is one of the most common sexually transmitted infections (STIs).
  • It is associated with increased rates of:HIV transmissionComplications in pregnancyInfertilityCervical intraepithelial neoplasia
  • STI screening, including HIV testing, should be performed on all patients with T. vaginalis infection.
  • HIV transmission
  • Complications in pregnancy
  • Infertility
  • Cervical intraepithelial neoplasia