There can be but little doubt that in many of the cases cited by Murchison as instances of the spontaneous origin of typhoid fever there was an introduction of the germs of the disease from without. At all events, the evidence to the contrary is by no means convincing. For example, in the account of the outbreak at the Westminster School it is expressly stated that "the contents of several small cesspools had been pumped before the outbreak of the fever" into the large cesspool, the emanations from which it was believed had caused the fever. It does not seem that it was positively ascertained that none of these small cesspools had been used by a typhoid-fever patient, or that typhoid stools had not found their way into them in some other way. Moreover, in diseases generally admitted to be contagious it is not always possible to ascertain positively the source of infection in a particular instance. But after the elimination of all doubtful cases there yet remains a certain number in which it is reasonably certain that there has been no recent importation of the typhoid-fever germs, as in the case which is reported by Metcalfe and which occurred on Norfolk Island, and in that recorded by Low. The assumption does not seem an unwarranted one that in these cases the poison of the disease, which had been present before in a latent condition, had been suddenly called into activity by favoring influences. The following observation of Von Gietl38 shows the length of time typhoid-fever stools may retain their infective properties: "To a village free from typhoid an inhabitant returned suffering from the disease, which he had acquired at a distant place. His evacuations were buried in a dunghill. Some weeks later five persons, who were employed in removing dung from this heap, were attacked by typhoid fever; their alvine discharges were again buried deeply in the same heap, and nine months later one of two men who were employed in the complete removal of the dung was attacked and died." If we assume—and there is no reason to doubt that this point was fully investigated by Von Gietl—that the patient in the latter case had not been otherwise exposed to the causes of the disease, the observation shows that the stools in typhoid fever retain their virulence for nine months. If for nine months, why may they not do so for a much longer period—for as many years, for example? No probability is violated by this hypothesis. On the contrary, it is in full accordance with what we know of some of the lower forms of life, and will serve to explain many outbreaks of the disease which would otherwise be inexplicable—for example, the outbreak at Clapham referred to by Murchison. Admitting that the disease in this instance was really typhoid fever—and this has been denied by some observers, among whom is Sir Thomas Watson—the assumption does not seem an unwarrantable one that the germs of typhoid fever had been present in this choked-up drain long before it was cleared, but that in consequence of their exclusion from the air their infecting power was at a minimum. It was, on the contrary, much increased when the contents of the drain were exposed to the vivifying influence of the atmosphere.
38 Quoted by Cayley, Brit. Med. Jour., Mar. 15, 1880.
On the other hand, it is alleged that an individual may be exposed to the direct emanations of sewers or of foul privies, or even drink water contaminated by leakage from them, without contracting typhoid fever, so long as they do not contain the specific germ of the disease. Every physician in large practice, either in the city or country, can call to mind instances in which the air of houses or the water-supply has been polluted in this way, and yet no typhoid fever has occurred. Let, however, the specific cause of the disease be introduced from without, and this immunity almost invariably disappears. There is no reason to believe that the contamination of the water used by the family which suffered in the outbreak of the disease which has been already referred to as having come under my own observation last year was of recent origin. On the contrary, there was evidence to the contrary, and yet no disease occurred until it was imported by a member of the family who was in the habit of making frequent visits to the city. Even more strongly corroborative of this view is the history of the epidemic reported by Ballard, in which milk was the medium of communication. The water which had been used with impunity to wash the milk-pans, or perhaps to dilute the milk, became a source of danger only after the occurrence of the disease in the family of the dairyman.
Several epidemics of typhoid fever have been recently reported in which the disease appears to have been caused by the use of the flesh of diseased animals or of meat in a condition of putrefaction. In some of these the symptoms were rather those of irritant poisoning than of typhoid fever, and consisted principally in violent vomiting and purging coming on very shortly after the ingestion of the unwholesome food. There yet remains a certain number in which the symptoms cannot be thus explained.39 One of the most remarkable of these occurred in 1878 at a festival which was held at Kloten, a place about seven miles north of Zurich, of which the following is a condensed description: Out of 690 persons who sat down to the collation, 290 were taken ill; 378 other persons, who did not attend the festival, but who partook of the meat provided for it, were also affected. In addition these, 49 secondary cases occurred—i.e. of persons who subsequently became affected without having eaten of the meat. All other sources of infection could be certainly excluded, as Kloten was quite free from typhoid fever at the time, and as it was clearly shown that the water was not the cause of the outbreak. All the visitors at the festival who ate no meat escaped, as did also several persons who drank wine to excess and subsequently vomited. The period of incubation was short, as in other epidemics arising from the same cause. Some of the people were ill on the second day, with loss of appetite, nausea, headache, pain and swelling of the belly, and slight fever. These cases were slight, and generally ended in recovery. The greater number were affected between the fifth and ninth days. The symptoms in these cases, which usually ran a rapid course, and generally ended in recovery, were chills, fever, diarrhoea, great prostration, frequently violent delirium, and also profuse intestinal hemorrhage. The rose-colored eruption was present in almost all of them, and in a few the tâches bleuâtres were detected. On post-mortem examination the characteristic appearances of typhoid fever were found. With regard to the meat supplied, the following facts were ascertained: Forty-two pounds of veal were furnished by a butcher at Seebach, taken from a calf which appears to have been at the point of death when it received the coup de grace from the hands of the butcher. All the flesh of the animal was sent to supply the festival at Kloten, but the liver was eaten by an inhabitant of Seebach, and he was attacked by typhoid fever. The brain was sent to the parsonage at Seebach, and all the household became affected by the same disease. It was also ascertained that another of the calves was diseased. The veal from this calf had been kept fourteen days, and was in a decomposed state. All the meat was placed together in the meat-receptacle of the inn at which the festival was held. This receptacle was in a horribly filthy state, and Cayley thinks there can be no doubt that the putrefying flesh of this last calf, together with the state of the receptacle, would rapidly excite decomposition in the whole supply.
39 On Some Points in the Pathology and Treatment of Typhoid Fever, by William Cayley, London, 1880; also Prof. Huguenin, Schmidt's Jahrbuch, from Schweiz. Corr. Bl., viii. 15, 1878; Carl Walder, Schmidt's Jahrbuch, from Berl. klin. Wochenschr., xv. 39, 40, 1878; George R. Shattuck, M.D., Supplement to Ziemssen's Cyclopædia, New York, 1881.
Geissler, it is true, doubts whether the epidemic above described was really typhoid fever, and points out that the symptoms occurred too soon after the ingestion of the diseased meat, and reached their full development too rapidly. The cases were also accompanied by more pain in the abdomen than is generally met with in typhoid fever. The proportion of recoveries also appears to have been unusually large. Unquestionably, the patients in the Kloten epidemic were in a large number of instances simply suffering from the action of an irritant poison; but the presence of the characteristic lesions of typhoid fever in some of the fatal cases renders it certain that this disease also existed in the village at the same time.
In the report of this epidemic it is not stated that either of the calves which furnished a part of the meat for the entertainment were suffering from typhoid fever at the time they were slaughtered. It is now known positively that this animal is liable to be attacked by this disease, and a certain number of cases are on record in which the eating of the flesh of such animals has been followed by typhoid fever.40 That it does not oftener occur from this cause is probably due to the fact that a certain time must elapse before the flesh of such an animal acquires infective properties, and that it is usually used as food before this has been allowed to pass.
40 Medical Times and Gazette, Feb. 8, 1879, p. 149, from Berl. klin. Wochenschrift, No. 39, 1878.
Ludwig Letzench41 asserts that he has produced some of the intestinal appearances of typhoid fever, as well as a high degree of pyrexia, in rabbits by the subcutaneous injection of the sputa and stools of typhoid fever patients.
41 Arch. f. exper. Pathol. u. Pharmak., 1878 and 1881.