Intravenous Serotherapy of Weil's Disease (spirochæetosis Icterohæmorrhagica)

We have already reported 1 the results of our studies with subcutaneous injections of immune serum in spirocha~tosis icteroh~emorrhagica. In the present article are presented the results of injections made by the intravenous method, which has in the main been employed in the serotherapy of Weil's disease since May, 1916. The number of patients treated in this manner in our clinic from May, 1916, to November, 1916, was 41. We found that the intravenous injection of immune serum far exceeds in potency the subcutaneous injection. An explanation of this finding may be sought in the fact that the therapeutic effect of serum injected directly into the blood stream is 500 times more potent than when it enters the organism by the subcutaneous route (Berghaus). Experiments to show the comparative effects of the subcutaneous and intravenous administration of serum in Weil's disease were undertaken with seven rabbits, the animals receiving 0.5 to 1 cc. of immune serum per kilo of body weight. At various intervals the blood of the animals was examined for spirocheticidal and spirochetolytic immune bodies. The blood was taken from the ear vein on the side opposite the one in which the intravenous injection was made. The results of these experimentsare given in Table I. The immune bodies could be demonstrated as complete 5 minutes after the intravenous injection of 0.5 cc. of serum per kilo of body weight, while with the subcutaneous method the immune bodies