B. pestis in blood, bile and urine

Although numerous investigators have examined the blood of patients with plague for B. pestis, no one has yet advanced any convincing explanation of the relation of bacilli in the blood to the development of plague. From the results of examination of test animals, Tsurumi and his coworkers 1 and others state that in plague infection the circulating blood acts only as a carrier of bacilli from the infected location to other tissues, but that the appearance of bacilli in blood is not a specific condition for the development of the disease. According to Sata,2 who studied this subject in detail both bacteriologically and anatomically, at the beginning of the infection, bacilli are held chiefly at the point in which inoculation took place, or in neighboring lymph nodes. The bacilli, however, have a great tendency in time to enter the circulating blood and grow in it. As a result, there occurs an intensive production of toxin with the characteristic severe symptoms and plague septicemia develops. As to the presence of bacilli in the bile, no detailed examination appears to have been made. In Tsurumi's experiments in 13 fatal human cases of plague and 9 animal cases, no positive result was obtained, and he ascribed this to the unfavorable conditions in bile for the growth of pest bacilli. In a previous paper 3 on B. pestis in blood of patients with plague, it is pointed out that the examination for B. pestis in the circulating blood is best made by cultivating on bile medium or 1% sodium citrate broth. By this method, 72.2% of patients with pest gave positive results. Consequently, pest septicemia is not rare as reported heretofore, and its prognosis not absolutely bad. The presence of B. pestis in the blood should not be explained as due only to the invasion of the blood after it has been growing at the point of invasion; it may grow at the same