Demonstration of a spirocheticidal effect by chemical contraceptives on Treponema pallidum.

The worldwide resurgence of venereal diseases has prompted new investigations in methods of topical prophylaxis for the prevention of sexually transmissible diseases. This article reports on the results of experiments conducted with 5 over-the-counter chemical contraceptives for intravaginal use, which were tested to determine their spermicidal effect on Treponema pallidum. Samples of Treponema pallidum containing more than 10 million spirochetes/ml were exposed to the diluted contraceptives in vitro, and also used in rabbits by inoculation via the intratesticular route. Of the 5 contraceptives tested both Delfen cream and Ortho cream completely inhibited spirochete mobility within 2 minutes of exposure in all dilutions; Koromex jelly was completely effective at 50% and 20% dilutions; Emko foam, Because foam, and Betadine vaginal gel were effective at 50%, 20% and 10% dilutions. The physiologic saline solution used for control purposes did not decrease the mobility of the spirochetes even at 5 or more minutes exposure. The 12 rabbits inoculated with spirochetes after the spirochetes had been exposed to 1 of the diluted products did not develop infection. These experiments confirm the spirocheticidal effect of the 5 chemical contraceptives, and suggest the potential usefulness of such intravaginal contraceptives in preventing person-to-person transmission of syphilis.