Prolonged eradication of urogenital mycoplasmas after administration of tetracycline to men in the Antarctic.

Meatal swabs were obtained at intervals over 1 year from 23 men in the Antarctic. A 5-day course of tetracycline was given to twelve of them. In retrospect it was found that the antibiotic had been received by two men who were harbouring ureaplasmas, one of whom also had M. hominis. After treatment, these organisms were not found in any of the swabs taken over the next year, except in a swab from one of the men following sexual contact after this time. One of the twelve men developed N.S.U. just before arriving in the Antarctic. He responded clinically to a shorter course of tetracycline and ureplasmas were not recovered from a meatal swab immediately thereafter. However, without further sexual contact, ureaplasmas and disease recurred about a month later. This time, after a 5-day course of tetracycline, disease was not seen, and ureaplasmas were not isolated, over the next year. In contrast, ureaplasmas were isolated consistently over a year from two men who were not given the antibiotic. The evidence strongly suggests that, under natural conditions, the most likely cause of mycoplasmas, particularly ureaplasmas, recurring in the genital tract after apparently adequate tetracycline therapy, is re-infection as a result of sexual re-exposure.