4th Lecture
Trichomoniasis is a sexually transmitted infection caused
by the protozoa Trichomonas vaginalis. It is one of the
most common sexually transmitted diseases in the
United
States.
Women
with
trichomoniasis
may
experience various symptoms, including a yellow-green
vaginal discharge and vulvar irritation, or they may be
asymptomatic. Men with trichomoniasis are frequently
asymptomatic.
The high incidence of trichomoniasis worldwide, its
contribution to poor health outcomes, and its co-infection
with
other
sexually
transmitted
infections
make
trichomoniasis a compelling public health concern.
Notably, T vaginalis infection is believed to increase the risk
of HIV transmission.
Trichomoniasis is also associated with adverse pregnancy
outcomes,
infertility,
cervical neoplasia.
postoperative
infections,
and
Frequency
United States
Approximately 8 million new cases of trichomoniasis occur annually. In
men, trichomoniasis accounts for 10-21% of urethritis cases not
attributable to gonorrheal or chlamydial infection.
International
Worldwide, the annual incidence of trichomoniasis is about 170 million
cases. The incidence of trichomoniasis in Europe is similar to that in
the United States. In Africa, the prevalence of trichomoniasis may be
much higher.
The infection is highly associated with the presence of
other sexually T vaginalis transmitted infections,
including gonorrhea, chlamydia, and HIV.
In men, complications of untreated trichomoniasis
include prostatitis, epididymitis, urethral stricture
disease, and infertility. Infertility may result from a
decreased sperm motility and viability.
T vaginalis is approximately the size of a white blood cell
(about 10 μm in diameter), although its size may vary
with physical conditions. Its flagellum allows it to move
around vaginal and urethral tissues.
T vaginalis directly damages the epithelium, leading to
microulcerations of inhabited tissues, increasing the risk
of HIV transmission.
Symptoms of trichomoniasis typically occur after an
incubation period of 4-28 days.
In women, T vaginalis is isolated from the vagina,
cervix, urethra and bladder.
In men, the organism is found in the anterior urethra,
external
semen.
genitalia,
prostate,
epididymis,
and
Women
Women with trichomoniasis frequently report a frothy yellowish-green
vaginal discharge, abnormal vaginal odor, vulvovaginal itching and
soreness, dyspareunia (pain during sexual intercourse), and
dysuria (pain during urination). Cervicitis due to trichomoniasis
is characterized by 2 major signs—purulent discharge in the
endocervical canal and easily induced endocervical bleeding.
T vaginalis infection is one of the top 3 causes of vaginitis. Vaginitis is
usually characterized by vaginal discharge, which may be
accompanied by vulvar itching, irritation, and odor.
Men
Trichomoniasis symptoms in men range from none to
urethritis complicated by prostatitis. Nongonococcal
nonchlamydial urethritis is the most common symptom
reported by men with trichomoniasis.
Symptoms of urethritis include discharge, dysuria, and
urethral pruritus. The discharge may be purulent to
mucoid in character.
All the trichomonads are morphologically
similar, having a pear-shaped body 7- 23
μm long, a single anterior nucleus, three to
five forward-directed flagella, and a single
posteriorly directed flagellum that forms
the outer border of an undulating
membrane.
Trichomonads have the simplest kind of
protozoan life cycle, in which the organism
occurs only as a trophozoite. Division is by
binary fission. Because there is no resistant
cyst, transmission from host to host must be
relatively direct.
A wet mount preparation of discharge from the patient should be
examined microscopically as a first step in diagnosing T vaginalis
infection. The presence of typical pear-shaped trophozoites,
usually 7 to 23 μm in length, with "bobbling“ motility and, on
careful examination, the wavelike movement of the undulating
membrane, are usually sufficient to identify T vaginalis.
Material that is negative by wet mount examination should be cultured
because culturing is a considerably more sensitive, although timeconsuming, method of diagnosis.
Metronidazole is effective in both males and females.
Vinegar douche may be useful.
Personal hygiene and the use of condoms are helpful.
Thank you