Trichomonas, Emergency Medicine

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)