Immunization experiments and scrotherapeutic trials will be dis cussed in the chapter on treatment.
It is important to differentiate the typhoid bacillus from the bac terium soli, which, morphologically, culturally, and, as recent investi gations made by G. Satins show, genetically, is closely related to the bacillus typhosus. The bacterium call, according to the some investigator, is said to form the same aggresin (in the sense of Bail) as the typhoid bacillus. If so, the identity of the two species, as already assumed by ninny, becomes very probable. Likewise, reports from various sources, made during the last few years concerning para typhoid bacilli, show that in this group of schizomycetes there exist many similarities and affinities, and that the cultural differences are for the most part insufficient for a separation of the species.
The cultivation of the bacillus may be made from the living or the dead subject. The demonstration during life has a great prophylactic value, and we may justly hail it as an essential advance that, by the method elaborated by Drigalski and Conradi, we are able to cultivate the typhoid bacillus from the dejections during the very first days of the disease and to separate them from other bacteria. The former methods, such as those of Elsner, Piorkowski, and others, were inade quate. By this means it was possible for Koch to recognize early and isolate the cases during the epidemic at Gelsenkirchen. Other places where the organisms may be found in the living are the spleen (from which the germs are obtained by puncture, a procedure that cannot be recommended) and in a very high percentage of cases the rose spots where they may be sought for without danger to the patient.
In the cadaver, the surest places to find the bacillus are the spleen, the mesenteric lymph-nodes and the gall bladder, where, according to the observations made at the Prague Pathological Institute and con firmed elsewhere, bacilli may be almost always demonstrated.
Besides the culture methods which enable us to differentiate the typhoid bacilli from morphologically similar organisms, and which are based essentially on the absence of gas formation, of indol production, and of coagulation of milk, we possess quite a reliable method of recog nition in agglutination which will be discussed later.
Pathological the post-mortem findings in an adult are quite characteristic, those in children, especially in the first years of life, are much less typical; ulceration for the most part is want ing and the changes are confined to a slight infiltration of the agminated and later of the solitary follicles, such as occurs in severe enteritis. Moreover, we find in the earlier stages catarrhal swelling and hyper :Tuna of the niucosa in the lower part of the ileum and in the region of the ileocecal valve, at times extending also to other portions of the small intestine, and considerable infiltration of the mesenteric glands corre sponding to the altered portions of the bowel. It is, however, the soft and enlarged spleen that particularly indicates typhoid fever. Other alterations that may be mentioned are a parenchymatous degeneration of the liver and kidneys, muscular degeneration of the heart, oedema and hyperemia of the meninges and cerebral substance, lobular and lobar pneumonia are almost constantly present, hyperremia of the bron chial mucous membrane, and such secondary infectious processes as suppuration of the middle ear, gangrene of the cheeks, suppuration of the parotid, purulent joint affections, etc.
We see from the above that the typical necroses, ulcers, and cica trices are missing, and, as Marfan forcibly remarks, we frequently have presented, especially in infants, a pathologico-anatomic picture more indicative of a septic amnia and a complete explanation only follows a bacteriologic examination.
Course of the Disease.—In childhood the course of abdominal typhoid is relatively mild, and the mortality correspondingly small. During the time I have been preparing this article and in spite of the great prevalence of typhoid in our city, I have been unable to obtain any material from post - mortem examinations of children to have pictures made.