777 /: RELATION or BACTERIA TO DISEASE 



penetrate through the injured walls and cause peritonitis or general 

 infection. Under certain conditions, as during the debility due to hot 

 weather, the bacteria in the intestines cause, through their products, 

 irritation, and in children even serious intestinal inflammation. 



The kidneys, bladder, and urethra may be the source of infection 

 and may give rise to disease. Long after an acute gonorrhoea has 

 passed gonococci may remain in sufficient numbers to cause a new 

 inflammation or produce infection in others. A cystitis may run on 

 chronically for years, and then suddenly become acute or spread infec- 

 tion to the kidneys. A persistent gonorrhceal vaginal infection may 

 lead to a gonorrhoeal endometritis, or salpingitis, or peritonitis, under 

 suitable conditions. The staphylococci in the skin and the colon 

 bacilli and pyogenic cocci in the fecal discharges may also be carried 

 into the bladder and uterus and produce septic infection. 



Occasionally the casting off of the bacteria allows them to infect 

 other places, as in some cases where laryngeal and intestinal tuber- 

 culosis follow pulmonary tuberculosis. We must bear in mind, how- 

 ever, that infection in these regions may have been produced through 

 the lymph- and blood-channels. 



In nearly all cases of infection the products of bacterial growth are 

 absorbed into the blood, and along with them a few bacteria also, even 

 when they do not reproduce themselves in it. The greater the extent 

 of the infection and the more deep seated it is, the greater is the amount 

 of absorption. The bacteria enter the blood, according to Kruse, by 

 (1) passive entrance through the stromata of the capillary walls; (2) 

 carriage into the blood in the bodies of leukocytes; (3) growth of the 

 bacteria through the walls of the vessels; (4) transmission of the bac- 

 teria through the lymph glands placed between the lymph- and blood- 

 vessels. 



When bacteria are abundant in the blood they become fixed in the 

 capillaries of one or all of the organs, especilly of the liver, kidneys, 

 spleen, and lungs, and then, by means of the leukocytes, which pene- 

 trate the capillary walls, or, directly, they pass into the tissues and 

 substance of the organs. They thus reach the lymph channels and 

 glands, or through the secretions gain entrance into the gall-bladder, 

 saliva, etc., or press through the epithelium, as in the alveoli of the 

 lungs; more rarely they pass through the excretions into the urine, as 

 in typhoid fever, though some deny that this can happen unless there 

 is a previous inflammation of the kidneys. 



Elimination of Bacteria through the Milk. The passage of bacteria 

 through the breast is important, from the fact that milk is so largely 

 used as food. Many observers have reported the finding of tubercle 

 bacilli in milk when the gland itself was intact and the animal tuber- 

 culous. Some authorities have put its presence in milk, under these 

 circumstances, as high as 50 per cent, of the cases. This, in our experi- 

 ence, is undoubtedly too high, and probably these observers have been 

 deceived by the pseudotubercle bacilli. They are undoubtedly present, 

 however, in the milk of some animals in which tuberculous disease of 



