Host Susceptibility to Typhoid, Dysentery, Food Poisoning and Diarrhea

One of the notable achievements in preventive medicine has been the control of the communicable diseases spread largely through alvine discharges. This has been accomplished by limiting the distribution of the typhoid bacillus by sanitary measures and, to a lesser extent in the civilian population, by specific prophylactic immunization. My purpose in this communication is to call attention to certain new factors that influence the distribution of bacteria in alvine discharges, and, what is even of greater importance, changes in the susceptibility of the host due to disturbances of the normal gastro-intestinal functional activities. The acidity of the gastric contents acts as a barrier to the passage of viable bacteria into the small intestine. Recent workers have shown that this is not a trustworthy germicidal agent under ordinary circumstances.1Bacteria introduced directly into the duodenum are usually killed before reaching the large intestine. Arnold and Brody2have recently