Part 8 (2/2)

Another way to exclude all possibility of tubercular infection inanimals This method is often follohere pasteurization or sterilization is not desired In dairies where the keeping quality is dependent upon the exclusion of bacteria by stringent conditions as to ienic” milk), the tuberculin test is frequently used as a basis to insure healthy milk

~Foot and mouth disease~ The wide-spread extension of this disease throughout Europe in recent years has given abundant opportunity to show that while it is distinctively an anih the disease is rarely fatal The causal organism has not been determined with certainty, but it has been shown that the milk of affected anih appearing unchanged in earlier phases of the disease

Hertwig showed the direct transmissibility of the disease tomilk from an affected animal, he was able to produce the sy covered with the small vesicles that characterize the malady It has also been shown that the virus of the disease may be conveyed in butter[99] This disease is practically unknown in this country, although widely spread in Europe

There are a number of other bovine diseases such as anthrax,[100]

lockjaw,[101] and hydrophobia[102] in which it has been shown that the virus of the disease is at times to be found in the milk supply, but often thethe sareatly minimized

There are also a nuet or mammitis In ed, and often pus is present to such a degree as to give a very disagreeable appearance to thebacteria (staphylococci and streptococci) are to be found associated with such troubles A nuastric and intestinal catarrh have been reported as caused by such milks[103]

DISEASES TRANSMISSIBLE TO MAN THROUGH INFECTION OF MILK AFTER WITHDRAWAL

Milk is so well adapted to the develop to find it a suitable enic species even at ordinary te bacteria are able to grow in raw milk in coht contamination may suffice to produce infection

The diseases that are most frequently disseminated in this way are typhoid fever, diphtheria, scarlet fever and cholera, together with the various illy-defined intestinal troubles of a toxic character that occur in children, especially under the name of cholera infantum, summer complaint, etc

Diseases of this class are not derived directly from animals because cattle are not susceptible to the same

~Modes of infection~ In a variety of ways, however, theinfluences after it is drawn froive opportunity for the develop bacteria The more important methods of infection are as follows:

_1 Infection directly fro case of disease on pree of a diseased condition may continue at his usual vocation as helper in the barn or dairy, and so give opportunity for direct infection to occur In the so-called cases of ”walking typhoid,” this danger is emphasized It is noteworthy in typhoid fever that the bacilli frequently persist in the urine and in diphtheria they often remain in the throat until after convalescence In soe of the milk in rooms in the house where it became polluted directly by the es of the lower classes where a single room has to be used in common this source of infection has been h the medium of another person_ Not infrequently another individual may serve in the capacity of nurse or attendant to a sick person, and also assist in the handling of thefor the milk after it has been drawn

Busey and Kober report twenty-one outbreaks of typhoid fever in which dairy employees also acted in the capacity of nurses

_3 Pollution of milk utensils_ The most frequenttheanisms Often wells in, as in typhoid fever, and the use of water at norive conditions per of infection Intentional adulteration of milk ater inadvertently taken from polluted sources has caused quite a nuwick and Chapin[106] found in the Springfield, Mass, epidemic of typhoid that the milk cans were placed in a well to cool the milk, and it was subsequently shown that the as polluted with typhoid fecalin infected water_, or by washi+ng same with contaminated water This method of infection would only be likely to occur in case of typhoid An outbreak at the University of Virginia in 1893[107] was ascribed to the latter cause

_5 Pollution of creamery by-products, skim-milk, etc_ Where the enic bacteria, it is possible that disease h thein the ski the mixed supply This condition is reater tolerance of this organism for acids such as would be found in raw land, in 1893, Castle Island,[109] Ireland, and Marlboro,[110] Mass, in 1894, were traced to such an origin

While most outbreaks of disease associated with a polluted inate in the use of the milk itself, yet infected milk may serve to cause disease even when used in other ways Several outbreaks of typhoid fever have been traced to the use of ice crea that the milk used in the manufacture of the product was polluted[111] Hankin[112] details a case of an Indian confection ely froih the evidence thatdisease is conclusive enough to satisfactorily prove the proposition, yet it should be borne in anism of any specific disease in question has rarely ever been found The reasons for this are quite the saovern the situation in the case of polluted waters, except that the difficulties of the problereater in the case of milk than ater The inability to readily separate the typhoid geranism frequently found in milk, presents technical difficulties not easily overcome The most potent reason of failure to find disease bacteria is the fact that infection in any case must occur sometime previous to the appearance of the outbreak Not only is there the usual period of incubation, but it rarely happens that an outbreak is investigated until a nuinal cause of infection may have ceased to be operative

~Typhoid fever~ With reference to the diseases likely to to be disse drawn from the animal, typhoid fever is the most important The reason for this is due (1) to the wide spread distribution of the disease; (2) to the fact that the typhoid bacillus is one that is capable of withstanding considerable amounts of acid, and consequently finds even in rawthe norrowth[113] Ability to grow under these conditions can be shown not only experimentally, but there is abundant clinical evidence that even a slight infection often causes extensive outbreaks, as in the Stamford, Conn, outbreak in 1895 where 386 cases developed in a feeeks, 97 per cent of which occurred on the route of one hly and properly cleaned, but were rinsed out with _cold_ water from a shalloell that was found to be polluted

The anisms is where the milk utensils are infected in one way or another[114] Second in i in the dual capacity of nurse and dairy attendant

~Cholera~ This germ does not find anism, because it is much more sensitive toward the action of acids Kitasato[115] found, however, that it could live in rawupon the arowsforms are thereby eliminated In butter it dies out in a few days (4 to 5)

On account of the above relation not a large number of cholera outbreaks have been traced tocase in India where a nu port, secured a quantity of milk Of the crehich consumed this, every one was taken ill, and four out of ten died, while those who did not partake escaped without any disease It was later shown that the milk was adulterated ater taken from an open pool in a cholera infected district

~Diphtheria~ Milk occasionally, though not often, serves as a medium for the dissemination of diphtheria Swithinbank and Newanisrowth occurs more rapidly in raw than in sterilized milk[118]

Infection in this disease is more frequently attributable to direct infection froerh the h it is more difficult to study the relation of this disease to contaerin of a considerable number of epidemics has been traced to polluted milk supplies Milk doubtless is infected es of the disease when the infectivity of the disease is greater

~Diarrhoeal diseases~ Milk not infrequently acquires the property of producing diseases of the digestive tract by reason of the development of various bacteria that form more or less poisonous by-products These troubles occurthe summer months, especially with infants and children, as in cholera infantuher mortality of bottle-fed infants[119] in comparison with those that are nursed directly is explicable on the theory that cows' milk is the carrier of the infection, because in many cases it is not consuanisms in it