A third set of cases, comprising thirty five, was characterized by enormous num bers of bacilli in the stools, among which proteus vulgaris was always found in large numbers. The ordinary obligatory milk-freces bacteria were also constantly present in very great excess of the nor mal, and in many of the cases a few streptococci and some other inconstant forms were also present. These were serious eases, usually chronic if not fatal, and characterized by emaciation and toxic symptoms. The stools were, as a rule, liquid, yellow or green in color, putrid, and neutral or alkaline in reac tion. They seldom, however, contained mucus, leucocytes, or epithelium.
In the fourth and last set of cases, twenty-seven in number, micrococci pre ponderated in the stools, though in ad dition bacillus coli was present in in creased number in all the eases, bacillus lactis in fourteen, and proteus vulgaris in four. The micrococci were for the most part streptococci. These cases were uniformly severe, and gave evidence of marked toxic disturbance. The stools were, as a rule, very frequent, often more than twenty in the twenty-four hours. They were soft or liquid, often greenish, and usually contained mucus and leuco eytes in abundance. They were also at times very offensive. Though very nu merous, the bacteria were not present in the stools in the enormous numbers met with in the third set of cases. Stained cover-glass preparations also showed them to be chiefly micrococci, not bacilli, as in the former cases. A general pytemic infection was a not infrequent outcome of these cases. Booker (Johns Hopkins Hosp. Reports, vi, 159, '06).
Conclusions based upon a study of thirteen cases of infantile diarrhcea:— 1. The bacterium coli appears to be the pathogenic agent of the greater number of summer infantile diarrhceas.
2. This organism is the more often as sociated with the streptococcus pyogenes.
3. The virulence, more considerable than in the intestine of a healthy child, is almost always in direct relation to the condition of the child at the time the culture is taken and does not appear to be proportional to the ulterior gravity of the case.
4. The mobility of the bacterium coil is, in general, proportional to its viru lence. The jumping movement, never theless, does not correspond to an exalted virulence in comparison with the cases in which mobility was very considerable without presenting these jumping move ments.
5. The virulence of the bacterium coli found in the blood and other organs is identical to that of the bacterium coli taken from the intestine of the same sub ject. C. G. Coniston (Inter. Med. Mag., Feb. and Mar., '98).
The gastrointestinal diseases of nurs ing infants caused by bacteria divided as follows: (A) Ectogenous intoxications (through the ingestion of the poisons of fermented milk) : (a) toxic catarrh of the stomach and small intestines; (b) cholera infantum. (B) Chymous infec tions (endogenous intoxication through abnormal fermentation of intestinal con tents, producing, first, a secondary irri tation and disease of the intestinal wall): (a) bacterial dyspepsia (acid diarrhoea); (b) dyspeptic catarrh (catarrh diar rhoea). (C) Intestinal infections (inflam
matory irritation or invasion of the in testinal wall by pathogenic bacteria): (a) inflammatory catarrh (inflammatory diarrhoea); (b) inflammation, gastritis, gastro-enteritis, enteritis, enterocolitis, colitis.
Mixed infections are frequently met with, and play an important part in the complications and sequelx. The facility of lactic fermentation and the slight re sistance of the infant's stomach render infection particularly easy. The most frequent bacteria are the staphylococci, the streptococci, bacterium coli, strepto thrix, and pyocyaneus bacillus. Theo dor Escberich (Wiener klin. Woch., Sept. 20, 1900).
The anatomical lesions met with in the intestinal tract of the infant, as the re sult of the diarrhoea, are of a varied character and are due apparently to the intensity of the irritant and the period of time during which its action has per sisted. Nevertheless, it must be acknowl edged that there is frequently a surpris ing want of relation between the post mortem evidence of disease and the se verity of the clinical phenomena and vice versa: a lack of relation, which thus far pathologists have not satisfactorily explained. Attempts have been made at a classification, but it is generally ad mitted that although cases may be grouped according to the prominence attained by certain lesions, no distinct dividing lines can be drawn.
In the more acute cases the lesions are comparatively superficial. In such, to the naked eye, the stomach and portion of the small intestine may ap pear almost normal; toward the lower end of the ileum and throughout the colon, indications of inflammatory dis turbance are to be seen; as a rule, they are specially pronounced in the region of the sigmoid flexure. The most impor tant of these indications are irregular patches of local congestion, and more or less swelling with hypertemia of the soli tary glands and of Peyer's glands. Under the microscope hardened sections of the intestinal wall show, in places, loss of superficial epithelium. This is especially noticeable toward the lower portion of the ileum and over the whole of the colon, where a considerable infiltration of the mucosa with leuco cytes may frequently be seen. In some instances an invasion of the mucosa by bacteria takes place in areas where the epithelium is absent (Booker). These local conditions are by no means to be taken as a measure of the general sys temic disturbance, for in a proportion of cases the manifestations of an acute gen eral infection are pronounced; evidenced in the liver by fatty degeneration and sometimes necroses of liver-cells, in the kidney by necrosis of the epithelium in the convoluted and irregular tubules, and in the lungs by a lobular pneumonia.