The male reservoir of Ureaplasma urealyticum.

Ureaplasma urealyticum organisms are often transmitted at birth from mothers to their infants. In males the organisms disappear from all anatomical sites usually within a few months. Around puberty they begin to be found again in the male urogenital tract and are present in the urethra of a varying proportion of men thereafter. Colonization increases with an increase in the number of sexual partners. In the United States about 45% of male college students without overt disease, who had had three or more partners, were found to carry ureaplasmas. In a somewhat older age group, about one-third of men attending a vasectomy clinic in the United Kingdom were colonized and 49% of men considered to be of normal fertility, but who accompanied their wives to an infertility clinic, had ureaplasmas in their semen. Data from 31 different studies in the past two decades indicate that 7 to 63% (mean, 34%) of "healthy" men attending sexually transmitted disease clinics were colonized by ureaplasmas in the urogenital tract and 19 to 85% (mean, 56%) of men with nongonococcal urethritis were colonized likewise. Circumcision does not seem to much affect the isolation of ureaplasmas, at least in men with disease. Oral colonization occurs less frequently than urogenital tract colonization and the organisms are able to persist in the latter site usually for years in the absence of sexual contact.