2. • It includes a group of flagellated protozoa
that infect humans and animal
• Common sexually transmitted protozoon
• Common at the age of 16-35 (sexually
active period)
• More pathogenic in women than men
Trichomonas
3. Trichomonas vaginalis
Geographical distribution:
•World wide, in all climates and all populations
NOTE:
1- Suitable pH for the parasite is 4.5 – 6 (low acidic).
2- Rare among young girls / menopause women - parasite requires
estrogenized epithelium for survival.
3- High in population at high risk for other venereal diseases & poor
feminine hygiene.
Genus Trichomonas has 3 distinct species:
1- T. hominis which inhabit large intestine & non pathogenic.
2- T. tenax which inhabit oral cavity & commensals.
3- T. vaginalis is the Urogenital pathogenic flagellate
4. Morphology of Trophozoite stage:
* Average size 10-15 X 8 µ
* Pear shaped
•Single vesicular Nucleus anteriorly & a small antero-
lateral cytostome.
*Thin axostyle midway crossed by thick parabasal body
* Four anterior free flagella and a lateral marginal
flagellum that reach to about half of the body length.
Trichomonas vaginalis
No Cyst stage
6. Trichomonas vaginalis
Habitat: T. vaginalis trophozoite lives:
In the vagina and urethra of infected females.
In the urethra and prostate of infected males
Transmitted directly during sexual intercourse
from infected partner to the other.
Incubation Time: 4-30 days
8. Pathogenesis and Clinical picture
Trophozoites feed on mucosal surface of vagina and
urethra producing sloughing of squamous epithelial cells.
Asymptomatic (50%)
Profuse odorous discharge, burning, itching,
dyspareunia, frequency of urination and dysuria.
On examination:
Excessive discharge
diffuse vulval erythema
Vaginal wall inflammation
(Strawberry cervix)
In women
9. Infection is frequently asymptomatic
Symptoms appear when infection involves prostate or
higher part of uro-genital tract.
Thin discharge,
dysuria and nocturia
Enlarged tender prostate
and epididymitis
epididymus
prostate
urethra
In men
On examination
Pathogenesis and Clinical picture
10. Diagnosis
Microscopic examination of wet film from
discharge
Culture of discharge.
Detection of T.vaginalis antigen in discharge by:
Enzyme immunoassay.
Direct fluorescent antibody test.
Detection of DNA of the parasite by Molecular
techniques
11. Treatment
Metronidazole + Vinegar vaginal douche
Treatment of sexual partner simultaneously
Epidemiology and Control
Most common between humans at the age of 16-35
High incidence in ladies with deficient feminine hygiene
Use of condoms to prevent infection
