The Maidston epidemic was caused in a similar way.
The water from contaminated wells is a frequent source of disease, and this is more especially the case in smaller towns where there are neither water-works nor sewerage. Water from such wells is de ceptive, as it is frequently clear and sparkling and is preferred to that of a much purer quality.
Milk is frequently a medium of trans- ' mission. The bacilli arc introduced by washing of the pans with impure water. They will afterward multiply in the milk itself, which is a good culture-medium. Direct contamination may take place when those who milk the cows are in attendance upon typhoid patients. Milk allowed to remain open to the air may be contaminated by dust or by flies convey ing the bacilli.
Oysters are a not-infrequent source of contagion, and epidemics have been brought about by their consumption. The oysters are fattened in ponds com municating with the estuaries of rivers, the water of which is polluted with sew age.
Klein made an investigation with re gard to the presence of bacilli in oysters, and found them in only one instance in those supplied to the trader. He dem onstrated the fact that when oysters are placed in water containing bacilli these organisms will be found within the shells as late as the seventeenth day after their removal from the water, establishing clearly the possibility of the conveyance of typhoid fever by this means. It is probable that other articles of food may become contaminated by germs which arise from dried filth. Typhoid bacilli may also be taken in on the surface of raw vegetables which have been washed in water containing typhoid organisms.
The principal source of the bacillus is in the passages from the bowels of ty phoid patients. They are also given off in the urine, vomited matter, and spu tum, and they may possibly be exhaled from the lungs. _Not a great deal is known of the life of the micro-organism outside of the body. They multiply in water and in the soil.
Direct Contagion.—Cases of what ap peared to be direct contagion have from time to time been reported. The attend
ants upon patients become ill in so short a time that it did not seem possible that the fever was commenced in the ordinary indirect way. In such instances the ty phoid germ may be inhaled into the mouth and pharynx and afterward swal lowed. Practitioners in the country have sometimes observed that, when a case of fever is imported into a previously healthy home, the attendants will, inside of two weeks, be attacked by the disease_ Pathological Anatomy. — The lesions of typhoid fever are found principally in Peyer's patches and solitary glands of the small and large intestines in the mesenteric glands and in the spleen_ Changes are also found in the gall-blad der and the muscular structure through out the body, especially that of the heart. Ulceration of the stomach is very rarely present.
Peyer's patches are made up of a col lection of glands, and exist principally in the lower part of the small intestines. The change first noticed in them is an elevation above the surface, due to in filtration of the glandular structures with leucocytes. The elevation is usually of an elliptical form lengthwise with the lumen of the bowel. The induration is of a whitish or opaque appearance, and may extend beyond the glandular strict ure even through the muscular and serous coats of the intestines.
This swelled condition reaches its height about the end of the first or the beginning of the second week, when resolution may take place. In some death follows from the severity of the fever before the commencement of ne crosis of the glands.
The circulation in the patch becomes impeded by inflammatory exudations and by innumerable colonies of bacilli, which produce virulent toxins. The slough which begins to form on the surface may involve a part or a whole of the gland. It usually extends to the submucous coat, but may exist more deeply. Often the necrosis takes place in several different parts of a patch, and three or four dis tinct ulcerations may be found in one gland.