Generalized infection in syphilitic rabbits resulting from the inadequate salvarsan therapy

In the course of study of the spirocheticidal action of salvarsan in vitro it was observed that in very low concentrations, instead of exerting inhibiting action, salvarsan markedly stimulated the growth of spirochetes. 1 Later, on the bases of this observation one of us recommended the use of minute amounts of salvarsan in the medium for isolation of spirochetes in vitro. 2 At the same time it was suspected that introducing minute amounts of salvarsan might also stimulate the growth of spirochetes in vivo. Accordingly a number of male rabbits with experimental syphilitic orchitis as well as two infected females were treated with varying amounts of salvarsan (from 0.004 gm. per kilo down to 0.000004 gm. per kilo) and several of them developed generalized infection, whereas controls treated with large amounts (0.03 gm. per kilo to 0.005 gm. per kilo) or those left untreated showed no tendency to generalized lues during at least 14 months following the date of the experiment. In addition to the involvement of mucous membranes, skin and bones two rabbits developed keratitis. In one rabbit at the autopsy was found a gumma of the liver which was confirmed as such by several pathologists. One of the infected females lost her young twice and the progeny of the third pregnancy was distinctly inferior and all of the four young died within a month after birth.

The work reported above was carried out at the Laboratories of the Western Pennsylvania Hospital, Pittsburgh, in 1914-1916. While a brief verbal mention of these findings was made at the time 3 we have not thus far communicated our observations in print desiring first to confirm them on a larger number of animals. In view of the growing tendency to decrease the dosage of salvarsan in the treatment of syphilis, we feel it useful to call attention to the facts observed by us.