May cause premature rupture of membranes or preterm labor in pregnancy
May cause low-birth-weight newborns
May facilitate transmission of HIV
Prevalence:
3 " “5 million cases per year in US
35% of women treated in STD clinics
Overall prevalence 3.1%:
Prevalence in black women 13.3%
Incubation 4 " “28 days
May be asymptomatic
Etiology
Trichomonas vaginalis: ‚
Flagellated protozoan:
Commonly found in urethra, bladder, and Skene gland
Diagnosis
Other
Vaginitis:
Vaginal discharge is seen in <30% of patients
Frothy yellow/green to gray/white
Vulvar itching and irritation
Vaginal odor
Symptoms same as with bacterial vaginosis (caused by Gardnerella vaginalis) and vulvovaginal candidiasis (caused by Candida albicans)
Dysuria and urinary urgency
Painful sexual intercourse
Often asymptomatic (50%)
Cervix:
Diffuse erythema (10 " “33%)
Punctate hemorrhage " ”colpitis macularis or strawberry cervix (2%)
Abdominal pain uncommon
Male
Often asymptomatic (75%) or self-limited
Male to male transmission is uncommon
Nongonococcal urethritis:
20% of nonspecific urethritis
Scant discharge
Dysuria and urinary urgency
Complications:
Prostatitis
Epididymitis
Reversible sterility
Physical Exam
Female:
Vaginal discharge:
Frothy yellow/green to gray/white
Odor
Red ulcerations " ”vaginal wall and cervix
Male:
Scant discharge
Essential Workup
Treat empirically if high enough clinical suspicion
Females: Wet mount ( "Hanging-drop " ť):
60 " “70% sensitive in symptomatic patients
Saline wet mount from cervical/vaginal vault smear:
Requires immediate evaluation of slide
Many polymorphonuclear leukocytes (PMNs)
Motile, pear-shaped, flagellated trichomonads (slightly larger than leukocytes; seen in 60%)
Specimen from spun urine less sensitive
Absence of trichomonads does not rule out T. vaginalis infection (only present in 60 " “70%)
Many EDs not equipped to perform wet mount
Elevated vaginal pH (>4.5) common:
Not specific
Males: Wet mount insensitive
PCR reliable but not widely available
Diagnosis Tests & Interpretation
Lab
Culture:
95% sensitivity:
Prostate massage before collection increases sensitivity in males.
Do culture when trichomonads suspected but not confirmed by wet-mount microscopy
Point-of-care tests:
High specificity (>97%) but variable sensitivities
Polymerase chain reaction (PCR):
Expensive
Differential Diagnosis
UTI
Gonorrhea
Chlamydia
Bacterial vaginosis
Candidal vaginitis
Nonspecific vaginitis
Treatment
Ed Treatment/Procedures
Female:
Metronidazole 2 g PO once:
90 " “95% cure rate
Metronidazole 250 mg PO TID for 7 days (urethritis)
Tinidazole 2 g PO once:
86 " “100% cure rate
Metronidazole gel, less effective:
Not recommended
Pregnant:
Symptomatic:
Metronidazole (FDA category B)
Asymptomatic:
Treatment is controversial as it does not reduce incidence of premature rupture of membranes or preterm delivery
Metronidazole
Males (urethritis):
Metronidazole 2 g PO once
Tinidazole 2 g PO once
Metronidazole 250 mg PO TID for 7 days
HIV positive
Consider 7-day course of treatment because of evidence of increased single dose treatment failure
Treat sex partners to prevent reinfection
No sexual intercourse until both partners are asymptomatic and until after at least 1 wk after treatment completed
Advise using latex condoms
Avoid concomitant alcohol use with metronidazole:
No alcohol for 24 hr after last metronidazole as it precipitates Antabuse reaction
Follow-Up
Disposition
Discharge Criteria
All patients ‚
Pearls and Pitfalls
Typical treatment for nongonococcal urethritis (e.g., azithromycin, doxycycline) does not treat T. vaginalis.
Vaginitis in females not responding to treatment for bacterial vaginosis might be due to Trichomonas infection.
Nongonococcal urethritis in males not responding to azithromycin or doxycycline might be due to Trichomonas.
Additional Reading
Centers for Disease Control and Prevention. 2011 Sexually transmitted diseases surveillance. Available at http://www.cdc.gov/std/stats11/other.htm#trich.
Greer ‚ L, Wendel ‚ GD Jr. Rapid diagnostic methods in sexually transmitted infections. Infect Dis Clin North Am. 2008; 22:601 " “617.
Sutton ‚ M, Sternberg ‚ M, Koumans ‚ EH, et al. The prevalence of Trichomonas vaginalis infection among reproductive-age women in the United States, 2001 " “2004. Clin Infect Dis. 2007;45:1319 " “1326.
Wendel ‚ KA, Workowski ‚ KA. Trichomoniasis: Challenges to appropriate management. Clin Infect Dis. 2007;44:S123 " “S129.
Workowski ‚ KA, Berman ‚ S; Center for Disease Control and Prevention (CDC). Sexually transmitted diseases treatment guidelines, 2010. MMWR Recomm Rep. 2010;59(RR-12):1 " “110.
See Also (Topic, Algorithm, Electronic Media Element)
Gonococcal Disease
Pelvic Inflammatory Disease
Urethritis
Vaginal Discharge/Vaginitis
Codes
ICD9
131.01 Trichomonal vulvovaginitis
131.02 Trichomonal urethritis
131.9 Trichomoniasis, unspecified
131.00 Urogenital trichomoniasis, unspecified
131.03 Trichomonal prostatitis
131.09 Other urogenital trichomoniasis
131.0 Urogenital trichomoniasis
131.8 Trichomoniasis of other specified sites
131 Trichomoniasis
ICD10
A59.01 Trichomonal vulvovaginitis
A59.03 Trichomonal cystitis and urethritis
A59.9 Trichomoniasis, unspecified
A59.00 Urogenital trichomoniasis, unspecified
A59.09 Other urogenital trichomoniasis
A59.0 Urogenital trichomoniasis
A59.8 Trichomoniasis of other sites
A59 Trichomoniasis
SNOMED
56335008 Infection by Trichomonas (disorder)
81598001 Trichomonal vulvovaginitis (disorder)
30116001 Trichomonal urethritis
35089004 Urogenital infection by Trichomonas vaginalis (disorder)