The respiratory organs generally present evidences of disease; the lesions of laryngitis, bronchitis, pneumonia, hypostatic congestion of the lungs, and pleurisy have all been observed after death from typhus fever. Usually, the traces of previous inflammation of the larynx are but slight; in a few cases, however, ulceration has been found, but the ulcers are stated to be always minute and superficial. Ulcers are also occasionally found in the bronchi, and frequently indicate by their appearance the pre-existence of a much higher grade of inflammation. The bronchial mucous membrane is, however, oftener merely reddened and softened and covered with a tenacious frothy secretion. True pneumonia is of infrequent occurrence as compared with that of hypostatic congestion of the lungs, but it nevertheless does occur, and may be of either the catarrhal or croupous variety. When pleurisy exists, it is usually accompanied, according to Murchison, by purulent effusion into the pleural cavity. On the other hand, Lebert says the variety of inflammation of the pleura oftenest met with is the plastic. The intestines present no constant lesion. Gerhard says that in fifty examinations there was but in one case, and that doubtful in diagnosis, the slightest deviation from the natural appearance of the glands of Peyer. In a few cases the Peyer's patches have been found more prominent than usual, but not more so than they are in measles and in some other diseases. Lebert alone of recent authors makes a contrary statement. In an epidemic at Breslau, he says, the solitary glands, as well as the patches of Peyer, were the seat of small, isolated, and superficial ulcers, which were usually situated in the vicinity of the ileo-cæcal valve. The mesenteric glands are generally unaffected, but in the Breslau epidemic just referred to they were not infrequently found moderately swollen. In cases in which dysentery has occurred as a complication the characteristic appearances of the disease will of course be observed, as well as those of typhus fever. The spleen is generally softened and slightly enlarged. The enlargement is not, however, always present, as Gerhard found it in one only out of every five or six of the cases which he examined. Extravasations of blood into its structure are occasionally met with. The liver is usually congested, somewhat enlarged, and frequently under the microscope presents the appearances of commencing fatty degeneration. The kidneys often present unmistakable signs of renal disease in the swollen granular and more or less fatty condition of their gland-cells according to the duration of the disease. The muscles are darker in color than in health. Under the microscope they are found to have undergone the peculiar granular or waxy degeneration described by Zenker, and which have been fully referred to in the article on typhoid fever. Extravasations of blood are occasionally found in them, which may soften and form pseudo-abscesses.
Other post-mortem appearances which are met with less frequently than those above detailed are inflammation, and even ulceration, of the mucous membrane, of the bladder, inflammation of the salivary gland, peritonitis, and congestion of the pancreas and of the stomach.
The muscular tissue of the heart is generally softened and easily torn. It is not, however, as stated by some authors, invariably so, for in several cases in which it was examined by Da Costa it had undergone this change in one case only, in which there was no reason to suspect previous disease of the heart. The alteration is similar in kind to that which takes place in the voluntary muscles. An effusion of serum, which may be of a deep-red color from the transudation of the coloring matter of the blood, is sometimes found in the pericardial sac, as are ecchymotic patches upon the surface of the heart. The endocardium may be stained from the imbibition of blood. On the other hand, endo- and peri-carditis are excessively rare.
Notwithstanding the severity of the cerebral symptoms in typhus fever, there are few or no important changes found in the brain or its membranes after death. The sinuses are occasionally filled with dark fluid blood, and the appearances of congestion of the brain are sometimes present. In other cases there may be an increased amount of serum beneath the arachnoid and into the lateral ventricles, but not more than is often seen after death from other causes. Very rarely a slight film of hemorrhage has been found in the cavity of the arachnoid, and sometimes also the evidences of non-inflammatory softening of the brain. Actual inflammation of the meninges has only been detected in a very few cases. There may also be congestion of the spinal membranes, increase of the spinal fluid, and softening of the cord itself. The ganglia of the sympathetic system appear to undergo a form of granular degeneration.
DIAGNOSIS.—The diseases which most closely resemble typhus fever are typhoid fever, measles, meningitis, and typhoid pneumonia.
The circumstances under which typhoid and typhus fever occur are different. Typhoid is never generated by overcrowding, and if contagious at all is much less so than typhus. Prostration occurs much earlier and is usually much more marked in the latter. The eruption in the former does not appear until the eighth day, and comes out in successive crops, and usually disappears under pressure as long as it lasts, and therefore may be easily distinguished from that of the latter. The duration of typhus is from ten to twenty days; that of typhoid is rarely less than twenty-one. Nevertheless, cases are occasionally met with in which it is impossible to arrive at a correct conclusion as to their nature unless some light is thrown upon it by the existence of other and more characteristic cases in the same house or neighborhood. I have recently had under my care a case which eventually proved to be typhoid fever, but which I and many others who saw it at first believed to be typhus in consequence of the presence of an abundant eruption, which did not disappear under pressure, and was finally converted into petechiæ.
The eruption of typhus is sometimes found upon the face, especially in children, and then presents a considerable similarity to that of measles, which, however, usually appears a little earlier. There is, moreover, rarely the same amount of prostration or stupor in the latter disease, which is also attended by coryza and more bronchial catarrh than is often present in the former. The eruptions in the two diseases differ. In measles it is crescentic in shape, and is more elevated than in typhus. It is also brighter in color, disappears under pressure, except in malignant cases, as long as it lasts, and is followed by free desquamation of the cuticle, which is not often observed in typhus. The temperature may be high in the former, but it usually falls upon the sixth day.
In meningitis the headache is much more severe, and does not disappear upon the occurrence of delirium. It may be so severe as to cause the patient to cry out. The senses are painfully acute. There are intolerance of light and sound, and some hypersensitiveness of the surface, strabismus, inequality of the pupils or some other local paralysis, and retraction of the head. Nausea and vomiting are more common than in typhus, while the utter prostration of the latter disease is wholly wanting, and so is of course the characteristic eruption. The tâche meningitique is wanting in the latter, but too much reliance should not be placed upon either the presence or absence of this sign. The diagnosis is only likely to be difficult in those cases of typhus in which the delirium is active. In that form of typhus in which the symptoms simulate those of delirium tremens some difficulty may also be experienced in making a diagnosis, especially if the patient be a drunkard. In delirium tremens it will be remembered, however, that there is little or no elevation of temperature, that the skin is bathed in perspiration, the tongue moist, and the characteristic eruption absent. Typhoid pneumonia can be distinguished from pneumonia complicating typhus fever by the presence of the eruption in the latter.
Other diseases which have occasionally been mistaken for typhus fever are remittent fever, Bright's disease, giving rise to uræmia and purpura. It does not seem likely that even the severest forms of malarial fever should ever present such a resemblance to typhus fever as to make the differential diagnosis a matter of difficulty; but it would appear from the history of the latter disease given by Murchison that such a mistake has occurred in some of the Spanish American countries. The enlargement of the spleen and liver is much less marked than in remittent fever, and the remissions of temperature are much less decided. Uræmia may at times present a good deal of resemblance to the condition often seen in typhus fever after the supervention of coma or stupor, but the history of the case, the absence of fever and of eruption in the former, will generally enable us to distinguish between the two conditions. It should be remembered, however, that Bright's disease may occur in the course of typhus fever. Purpura may generally be recognized by the absence of fever and by the occurrence of hemorrhages from the nose, gums, and bowels.
PROGNOSIS.—The age, habits of life, and previous condition of health, as well as the character of the prevailing epidemic, must all be fully considered before making a prognosis in any special case. The disease usually runs a much milder course in children and young people than in adults past thirty years of age. After this age the mortality progressively increases, and in advanced life it becomes very high, being often as much as 50 per cent. or over. Sex does not of itself exercise much influence upon the course of typhus fever, for, although a few more men than women die of it, this appears to be attributable to the greater prevalence of drinking among the former. Previous intemperance acts unfavorably by producing a degeneration of the tissues of the body, thus rendering the patient less able to withstand the effects of the disease. Drunkards have therefore always furnished a large proportion of the fatal cases. The mortality among patients who are unfortunate enough to take typhus fever as they are convalescing from other diseases is usually also very great. This has often been observed in general hospitals in which cases of fever as well as those of other forms of disease are admitted. Fat, lymphatic, or muscular people more frequently die of it than those of a different conformation. Gerhard found it especially fatal among negroes in the epidemic of 1836, and Buchanan seems to have had a similar experience at the London Fever Hospital. It is a fact noticed by English writers that people of the better class, although seldom attacked by typhus, often suffer severely from it. The mortality is always high among those patients who previously to contracting the disease have been for some time deprived of sufficient food, or have been overworked, or who have been the subjects of mental anxiety, worry, or any other depressing emotion. It is high also among those who in the beginning of the disease have exhausted their strength in the vain effort to resist the disposition to go to bed. The chances of recovery are, on the other hand, very much improved by the removal of patients from crowded, ill-ventilated houses to the wards of a spacious, airy hospital.