Rocky Mountain Spotted Fever: Further Experience in the Therapeutic Use of Immune Rabbit Serum

Abstract

Refined immune rabbit serum was demonstrated, in laboratory animals, to have therapeutic value when given early. With small doses (1 ml./kg. body wt.), the therapeutic effect varied inversely with elapsed time from the inoculation of the infecting dose to the administration of the serum. During the summers of 1941 and 1942, the immune rabbit serum was administered to 71 human cases of Rocky Mt. spotted fever. 19 of these cases were treated after the 3d day of the rash (6-7th day of illness); little if any benefit was demonstrated. 52 of the cases were treated earlier (before the 3d day of rash); there were only 2 deaths in the group, both in [male][male] 66 and 72 yrs. of age respectively. There was in the treated group a fatality rate of 3.8% as compared to the expected rate of approx. 18.8%.