subsequently occur. These various symptoms persist throughout the third week, usually, however, increasing in intensity. The patient becomes prostrate and emaciated; the tongue is dry and brown, the pulse quickened and feeble, and the abdominal symptoms more marked; while nervous disturbance is exhibited in delirium, in tremors and jerkings of the muscles (subsullus tendinum). in drowsiness and occasionally in “coma vigil." In severe cases the exhaustion reaches an extreme degree, although even in such instances the condition is not to be regarded as hopeless In favourable cases a change for the better may be anticipated between the twenty-first and twenty-eighth days, more usually the latter. It does not, however, take place as in typhus by a well-marked crisis, but rather by what is termed a “lysis ” or gradual subsidence of the febrile symptoms, especially noticeable in the daily decline of both morning and evening temperature, the lessening of diarrhoea, and improvement in pulse, tongue, &c. Convalescence proceeds slowly and is apt to be interrupted by relapses. Should such relapses repeat themselves, the case may be protracted for two or three months, but this is comparatively rare. Death in typhoid fever usually takes place from one or other of the following causes. (1) Exhaustion, in the second or third weeks, or later. Sometimes sinking is sudden, partaking of some of the characters of a collapse. (2) Hæmorrhage from the intestines, The evidence of this is exhibited not only in the evacuations, but in the sudden fall of temperature and rise in pulse-rate, together with great pallor, faintness and rapid sinking. Sometimes hemorrhage, to a dangerous and even fatal extent, takes place from the nose. (3) Perforation of an intestinal ulcer. This gives rise, as a rule, to sudden and intense abdominal pain, together with vomiting and signs of collapse, viz. a rapid flickering pulse, cold clammy skin, and the marked fall of temperature. Symptoms of peritonitis quickly supervene and add to the patient's distress. Death usually takes place within 24 hours. Occasionally peritonitis, apart from perforation, is the cause of death. (4) Occasionally, but rarely, hyperpyrexia (excessive fever). (5) Complications, such as pulmonary or cerebral inflammation, bedsores, &c. Certain sequelae are sometimes observed, the, most important being the swelled leg, periostitis affecting long bones, general ill health and anaemia, with digestive difficulties, often lasting for a long time, and sometimes issuing in pulmonary tuberculosis. Occasionally, after severe cases, mental weakness is noticed, but it is usually of comparatively short duration. No disease has been more thoroughly studied in recent years than typhoid fever. The chief points requiring notice are (1) causation and spread, (2) prevalence, (3) treatment, (4) prevention.
Causation:-The cause is the bacillus typhasus, discovered by Eberth in 1880 (see PARASITIC DISEASES). This organism multiplies in the body of a person suffering from the disease, and is thrown off in the discharges. It enters by being swallowed and is conveyed into the intestine, where sets up the characteristic inflammation. It is found in the spleen, the mesenteric glands, the bile and the liver, not infrequently also in the bone marrow, and sometimes in the heart, lungs and kidneys, as well as in the faeces and the urine. It has also, though more rarely, been found in the blood. The illness is therefore regarded as a general toxaemia with special local lesions. The relation of the bacillus to the other numerous bacteria infesting the intestinal canal, some of which are undoubtedly capable of assuming a pathogenic character, has not been determined; but its natural history, outside the body, has been investigated with more positive results than that of any other micro-organism, though much still remains obscure. Certain conclusions may be stated on good evidence, but it is to be understood that they are all more or less tentative. (1) In crude sewage the bacillus does not multiply, but dies out in a. few days. (2) In partly sterilized sewage (Le. heated to 65° C.) it does not multiply, but dies out with a rapidity which varies directly with the number of other organisms present-the more organisms the quicker it dies. (3) It is said not to be found in sewer air, though Sir Charles Cameron, from a series of recent experiments, claims to have proved the contrary. (4) In ordinary water containing other organisms it dies in about a fortnight. (5) In sterilized water it lives for about a month. (6) In ordinary soil moistened by rain it has lived for 67 days, in sewage-polluted soil for at least 53 days, in soil completely dried to dust for 25 days, and in sterilized soil for upwards of 400 days. (7) Exposed to direct sunlight it dies in from four to eight hours. (8) It is killed by a temperature of 58 °C., but not by freezing or drying. (9) It multiplies at any temperature between 10° C. and 46° C., but most rapidly between 3 5° C and 42° C. These conclusions, which are derived from experiment, are to a considerable extent in agreement with certain observations on the behaviour of the disease on a large scale.
The susceptibility of individuals to the typhoid bacillus varies greatly. Some persons appear to be quite immune. The most susceptible age is adolescence and early adult life; the greatest incidence, both among males and females, is between the ages of IS and 3 5. The aged rarely contract it. Men suffer considerably more than women, and they carry the period of marked susceptibility to a later age. Predisposing causes are believed to be debility, depression, the inhalation of sewer air by those unaccustomed to it, and anything tending to “lower the vitality, ” whatever that convenient phrase may mean. According to the latest theories, it probably means in this Connexion a chemical change in the blood which diminishes its bactericidal power. The lower animals appear to be free from typhoid in nature; but it has been imparted to rabbits and other laboratory animals. There is no evidence that it is infectious in the sense in which small-pox and scarlet fever are infectious; and persons in attendance on the sick do not often contract it when sufficient care is taken. The recognition of these facts has led to a general tendency to underrate contagion, direct and indirect, from the sick to the healthy as a factor in the dissemination of typhoid fever; but it must be remembered that the sick, from Whose persons the germs of the disease are discharged, are always an immediate source of danger to those about them. Such personal infection may become a very important means of dissemination. There is evidence that this is the case with armies in the field, ag. the conclusions of the commission appointed to inquire into the origin and spread of enteric fever in the military encampments of the United States in the Cuban campaign cf 1898. Out of 1608 cases most thoroughly investigated, more than half were found to be due to direct and indirect infection in and from the tents (Childs: Sanitary Congress, Manchester, 1902). A similar but perhaps, less direct mode of infection was shown to account for a large number of cases under more ordinary conditions of life in the remarkable outbreak at Maidstone in 1897, which was also subjected to very thorough investigation. It was undoubtedly caused in the first instance by contaminated water, but 280 cases occurred after this cause had ceased to operate, and these were attributed to secondary infection, either direct or indirect, from the sick. A good deal of evidence to the same effect by medical officers of health in England has been collected by Dr Goodall, who has also pointed out that the attendants on typhoid patients in hospital are much more frequently attacked than is commonly supposed (Trans. Epidem. Soc. vol. xix.).
Recent discoveries as to the part played in the dissemination of typhoid fever by what are termed “ typhoid carriers ” have thrown light upon the subject of personal infection. The subject was first investigated by German hygienists in 1907, and it was found that a considerable number of persons who have recovered from typhoid fever continue to excrete typhoid bacilli in their faeces and urine (typhoid bacilluria). They found that after six weeks 4% to 5% of typhoid patients were still excreting bacilli; 23% of 65 typhoid patients at Boston City Hospital showed typhoid bacilli in their excretions ten days before their discharge. The liability of a patient to continue this excretion bears a direct relation to the severity of his illness, and it is probable that the bacilli multiply in the gall bladder, from which they are discharged into the intestine with the bile. The condition in a small number of persons may persist indefinitely. In IOI cases investigated, Kayser found three still excreting bacilli two years after the illness, and George Deane has recorded a case in which bacilli continued to be excreted ZQ years afterwards. Many outbreaks have in recent times been traced to typhoid carriers, one of the first being the Strassburg outbreak. The owner of a bakehouse had had typhoid fever ten years
