The following points highlight the three important species of Trichomonas for which man is host. The species are: 1. Trichomonas Vaginalis 2. Trichomonas Hominis 3. Trichomonas Tenax.
Species # 1. Trichomonas Vaginalis:
This is largest of three trichomonads of man. It averages about 13 um in length. The undulating membrane usually reaches to the middle of the body, but it may be shorter. There is no trailing flagellum. The parabasal body, with a parabasal filament, is large. The axostyle characteristically curves slightly around the nucleus. It lives in the vagina, urethra or in the prostate gland.
The disease caused by this parasite is called “Trichomoniasis”. T. vaginalis is cosmopolitan in distribution. The incidcnce of infection in women varies from 20 to 40% whereas in men it varies from 4 to 15%. The transmission is always through sexual intercourse by infected male who act as intermediaries. The sites of infection in the male are renal pelvis ureter urinary bladder, prostate, urethral glands, urethra and epididymis.
In women it inhabits the vagina and causes vaginitis. The parasites cause severe erosion of vaginal mucosa. The disease is characterized by inflammation, itching, burning sensation and white vaginal discharge. No cysts are produced. The parasite may even by found in newborn babies and children. Pathogenic strains have been found within the cytoplasm of macrophages and epithelial cells.
For treating Trichomoniasis, arsenic and iodine drugs and antibiotics like Aureomycin and Terramycinare quite effective.
1. Protection against T. vaginalis is achieved by injection of live and dead cultures.
2. Heat-killed cultures have been effective in preventing infection.
3. Infected males should avoid sexual contact until treated and completely cured.
Species # 2. Trichomonas Hominis:
It lives in the caecum and adjacent intestinal area in man. It is also found in monkeys, cats, dogs and rats. The body is oval in shape, measuring about 10 x 4 um with five anterior flagella (so also known as Pentatrichomonas) and a free posterior flagellum extending from the end of a long undulating membrane.
At its anterior end, it has a costa and a parabasal apparatus. Cysts are absent. It has a worldwide distribution, but infection is maximum in tropical countries. It is not a serious pathogenic parasite.
Species # 3. Trichomonas Tenax:
This flagellate lives in the human mouth. It is a harmless commensal. T. tenax is smaller than T. hominis, averaging about 7 u m in length. It is similar to T. hominis in general appearance, but the undulating membrane extends about two-thirds the length of the body. There is no trailing flagellum. The parabasal body is elongate and prominent.