Trichomonas vaginalis

Hosts: Man.

The golden hamster can be infected intravaginally (Uhlenhuth and Schoenherr, 1955). Mice can be infected subcutaneously (Honigberg, 1959).

Location: Vagina, prostate gland, urethra.

Geographic Distribution: Worldwide.

Prevalence: T. vaginalis has been reported in 2% to as high as 80 to 90% of women and in 1 to 47% of men in various surveys (Wenrich, 1947; Kucera, 1957; Burch, Rees and Reardon, 1959).

Morphology: The body is piriform, 7 to 23 by 5 to 12 u, and has 4 anterior flagella about as long as the body. The undulating membrane has 3 or 4 waves and extends a little more than half the body length. There is no free posterior flagellum. An accessory filament is present. The costa is very narrow. The parabasal body is long, cylindrical, and has a parabasal filament extending posteriorly from it. Paracostal and extra-axostylar granules are numerous; other siderophil granules are scattered in the cytoplasm. Four chromosomes are present. The axostyle is rather slender. The cytostome is inconspicuous.

Trichomonads of man

Pathogenesis: T. vaginalis infections are often asymptomatic in womena and are usually so in the male. Trichomonad vaginitis is characterized by leukorrhea and vaginal and vulvar pruritis. T. vaginalis may occasionally cause purulent urethritis and prostato-vesiculitis in the male. Concomitant bacteria and yeasts may exacerbate the symptoms and lesions.

Epidemiology: T. vaginalis infections are essentially venereal in origin, the organism being transmitted during sexual intercourse. In exceptional cases, infants have been infected from their mothers. Transmission thru contaminated towels, underwear or toilet seats is extremely rare.

Diagnosis: T. vaginalis infections can be readily identified by microscopic examination of vaginal secretions or scrapings, sedimented urine or prostate secretions obtained by massaging the prostate gland.

Cultivation: T. vaginalis can be readily cultivated in any of the media used for trichomonads, such as CPLM medium.

Treatment: A number of preparations are used in treating trichomonad vaginitis. Among them are suppositories containing chiniofon, diodoquin, vioform, carbarsone or oxytetracycline. Lactic acid douches are often used to make the vaginal pH acid and provide conditions unsuitable for the protozoa. Infections in the male may be treated by introducing oxytetracycline ointment into the urethra or irrigating with a sulfonamide or antibiotic. To prevent reinfection, both husband and wife should be treated.

Remarks: Trussell (1947) has written a definitive monograph on this species.