Influence of testicular fluid infected with Treponema pallidum on intradermal lesions.

A viscous mucoid fluid occasionally accumulates after intratesticular inoculation of rabbits with Treponema pallidum. Experiments were performed to assess the effects of this testicular fluid on the development of syphilitic lesions. Intramuscular injections of this fluid altered host defences as indicated by shorter incubation periods, by reactivation of healing lesions, and by the presence of lesions at a time when solid immunity should have developed.