- • In women, findings include motile trichomonads
visible on vaginal wet mount, positive culture for Trichomonas vaginalis,
and Pap smear result that is positive for trichomonads.
- • In men, diagnosis is often presumptive, after
failure to respond to standard treatment for nongonococcal urethritis
Trichomoniasis is one of the three major causes of symptomatic
infectious vaginitis, along with candidiasis and bacterial vaginosis,
and is the only one known to be sexually transmitted. Despite being
a readily diagnosed and treated infection, trichomoniasis is not
a reportable one, and control of the infection has received relatively
little emphasis from public health control programs for sexually
transmitted diseases (STDs). The annual incidence of Trichomonas
vaginalis infections in the United States has been estimated at
5 million cases. The World Health Organization has estimated that
this infection accounts for almost half of all curable STDs worldwide.
Trichomoniasis is the exception to the rule that applies to most
STDs in that it is more difficult to diagnose in men than in women.
Currently available diagnostic methods for trichomoniasis in men
lack sensitivity and availability. Therefore, most men are treated
either as a result of sexual exposure to an infected woman or as
part of an algorithm for persistent NGU.
Nanda N, Michel RG, Kurdgelashvili G, Wendel KA.
Trichomoniasis and its treatment. Expert Rev Anti Infect Ther
(Recent comprehensive review of trichomoniasis
Schwebke J, Hook EI. High rates of Trichomonas vaginalis among
men attending a sexually transmitted diseases clinic: Implications
for screening and urethritis management. J Infect Dis
(Study of the prevalence and association of Trichomonas
NGU in men).
T vaginalis, a flagellated parasite, is the causative agent of
this infection. Although two other species of Trichomonas infect
humans (Trichomonas tenax and Trichomonas hominis), T vaginalis
is the only one that infects the urogenital tract. Trichomonas infects
the squamous epithelium of the vagina and ectocervix and often causes
an inflammatory response in the host manifested clinically by purulent
discharge. The pathogenesis in men is poorly understood.
As with any STD, unprotected sex is a risk factor for acquisition
of infection. Limiting the number of sex partners or using condoms
helps to prevent infection.
Symptoms of trichomoniasis in women include vaginal discharge,
irritation, and pruritus; however, about half of all women infected
with T vaginalis are asymptomatic. Occasionally women report vague
lower abdominal pain. Signs of infection in women include vaginal
discharge, odor, and edema or erythema, but these may be absent.
Occasionally, erythematous, punctuate lesions may be seen on the
ectocervix, the so-called “strawberry cervix.”
In men, the prevalence and spectrum of disease is far less well
characterized; the infection usually appears to be asymptomatic;
however, it has been suggested as an increasingly important cause