442 INFECTION AND IMMUNITY, 



the most important factor in the immunity result- 

 ing from an attack. 



This is not clear from the clinical standpoint 

 because of the hypoleucocytosis which is some- 

 what characteristic of typhoid a hypoleucocytosis 

 caused chiefly by a disappearance of the micro- 

 phages. It has been suggested that our con- 

 clusions as to hypoleucocytosis are based on ex- 

 amination of the peripheral blood, whereas the 

 mesenteric vessels may show hyperleucocytosis. 

 Mallory, however, found a striking absence of 

 microphages even in the intestinal vessels. Con- 

 cerning a theory that the hyperplasia of the lym- 

 phoid organs serves as a substitute for the hyper- 

 leucocytosis, we may recall the findings of Mallory 

 that this hyperplasia is chiefly one of endothelial 

 cells. The importance of these endothelial cells 

 for the destruction of typhoid bacilli needs further 

 investigation. 



Prophylaxis. Prophylaxis should begin with the thorough 

 disinfection of the stools and urine of typhoid pa- 

 tients, and this should be continued until they no 

 longer contain typhoid bacilli. It is not good 

 hygiene to discharge a patient until bacteriologic 

 examination of stools and urine show them to be 

 free from the organisms. It would be difficult to 

 carry out this rigid precaution under all condi- 

 tions, but at all events the stools and urine may be 

 disinfected for a reasonable period, say through- 

 out convalescence. There is no sufficient reason 

 for the neglect of the bacteriologic examination in 

 hospital practice. There is a growing sentiment 

 that typhoid patients in hospitals should be iso- 

 lated in wards or rooms in which there is a fixed 

 routine for the disposal of infectious materials 



