Antistreptococcic Serum. - (Not official.) Streptococci do not cause the diseases due to them by developing a toxin which circulates in the blood, but by being themselves carried all over the body, which attempts to kill them by developing a toxin fatal to them. To prepare antistreptococcic serum the virulence of the streptococci is increased by their passage through several rabbits; they are then grown on a medium which preserves their virulence. A horse is next treated with successive doses of cultivations of these living streptococci, each more potent than the former.

At the end of the year the strength of the antitoxic serum of the horse is powerful enough for use. This is always given subcutaneously and the dose varies with different specimens of serum.

Action And Therapeutics Of Antistreptococcic Serum

Our experience of the value of antistreptococcic serum is limited, but it suggests itself as useful for those diseases which are principally due to infection by streptococci. Such are malignant endocarditis, erysipelas, surgical septicaemia, disease of the middle ear, thrombosis of the lateral sinus, and puerperal septicaemia. Successful cases of its use in these disorders have been recorded, and it might be used with advantage in any of the many diseases in which streptococci can be found. One great disadvantage of it is that it is always impossible to foretell whether it will be of use; this is because different cultivations of apparently the same streptococcus vary so widely in their properties that serum which is antibactericidal to one cultivation is not to another.