The utilization of “reactor” milk in tuberculo-medicine

Abstract

We cannot in the study of tuberculosis get away from the disconcerting observation that it is the infected individual who is immune or possessed of increased resistance to tuberculosis. Our previous works 1 on immunity and tuberculosis led me to endeavor to ascertain to what extent milch cows, that gave no clinical signs of tuberculosis, and yet reacted to tuberculin, could be considered immune or possessed of increased resistance. Furthermore, to ascertain if the milk and serum of such “reactors” gave evidence of possessing antibodies or other healing bodies not contained in the ordinary milk and serum of cows not infected with tuberculosis. It is occasionally observed that if a cow which has reacted to tuberculin, be allowed to live, it thrives, apparently even better than some of the non-infected members of the herd. Ten of these “reactors” which were in especially prime condition were carefully selected because they thrived, and gave the physical evidence of having withstood the natural infection, in short because they appeared to be immune or the disease arrested. The milk when injected into guinea-pigs did not produce tuberculosis. The milk was also tested by the Bordet-Gengou phenomenon for tuberculosis and gave negative reactions. The blood-serum of nine were also examined for this reaction; four were definitely negative, four gave a weak reaction, and one a decided reaction but not strong enough for diagnosis. One of these cows went dry and the milk of another was excluded because it readily killed mice in comparatively small doses, when injected subcutaneously. The serum of these cows, when added to glycerin-bouillon cultures of the tubercle bacillus did not inhibit their growth. The ten autopsies on these “reactor” cows showed slight localized lesions in the lungs, and in the bronchial and posterior mediastinal glands in nine cows and in one cow slight generalized lesions were found.