Pathology.—The assemblage of mor bid phenomena constituting typhus fever may be said to consist of diminished sensibility and activity of the nervous structures both voluntary and involun tary, with lessened muscular action; diminished oxygenation of the blood, with imperfect coagulation and impaired condition of red corpuscles; general diminution of secretions, with increase of urea and diminution of phosphates and frequently the presence of albumin in the urine; dark color of blood and tis sues, with progressive granular degenera tion of the cardiac and muscular struct ures generally, with enlargement and softening of the spleen, kidneys, and liver, congestion of the mucous mem brane of the air-passages, and hypostatic engorgement of lung-tissue. Such an assemblage of phenomena, all in the di rection of impairment of both function and structure, implies the presence of some virulent sedative ptomaine, leueo maine, or toxalbumin, or the absence of sufficient oxygen or other agent essen tial for the maintenance of the vital properties of the cell-protoplasm enter ing into the composition of the blood and tissues of the body. In the more se vere cases these universal changes pro gress with such rapidity that the heart fails to contract with sufficient force to maintain circulation of the blood, and the patient dies before the end of the first week from general suspension of the phenomena of life. In eases of less severity the same changes take place less rapidly, and fatal exhaustion is not reached until the end of the second week; while cases still milder reach a crisis in about two weeks, when critical evacuations from the skin, kidneys, or bowels occur, and convalescence ensues.
Prognosis.—From statistics gathered in the leading hospitals of London. Edin burgh, Glasgow, and Paris by Dr. Mur chison the average ratio of mortality from typhus was stated to be 18.8 per cent., or a little less than one in five. The ratio varies much in different epi demics. According to Dr. Murchison, the ratio of deaths in the London Fever Hospital in 1850 was GO per cent., and in Bellevue Hospital, New York, in 1869, it was nearly 20 per cent. In other epi demic seasons it has ranged as low as 8 or 9 per cent. The majority of sys tematic writers state the mortality-ratio as between 12 and 20 per cent.
In children the death-rate is much lower than in adults, and is greatest in old age. Many recorded facts show that the ratio of mortality in any epidemic of typhus fever is much influenced by the amount of fresh air supplied to the pa tients. A patient occupying a large, clean, and well-ventilated room or tent, not only has greatly increased chances of recovery, but he very rarely communi cates the disease to others who may come in contact with him. This was well illustrated when in 1864 the fever patients were removed from the crowded wards of Bellevue Hospital to tents on Blackwell's Island. In the hospital the death-rate had been from 18 to 20 per cent., and several of the nurses and house
physicians had died; but after their re moval to the tents with abundance of fresh air and little or no use of alcoholic remedies, the death-rate diminished to between 5 and 6 per cent., and the nurses and medical attendants remained unat tacked.
Prophylaxis. — The most important measures for preventing the develop ment and spread of typhus are the main I enancc of free ventilation, strict clean liness, wholesome food, pure water, pre vention of aggregating of many patients in one room or ward, and the exclusion of all but the necessary physicians and Treatment. — In the absence of all knowledge concerning the specific germ or other toxic agent on which the de velopment of typhus fever depends, our treatment must be founded on the indi cations presented by a careful study of the clinical phenomena of each case, and the known tendency to general granular or cell-degeneration in the various struct ures of the body. The first and most imperative indication is to secure for the patient an abundance of good fresh air and the enforcement of strict cleanliness of person, clothing, and room, and a judicious supply of pure water and liquid nourishment. The second indication is to repress the rapidly rising temperature of the first stage by frequent sponging or bathing of the surface with cool water, and to promote the natural secretions and eliminations from the skin, kidneys, and abdominal viscera generally, and thereby prevent the accumulation of waste and toxic products in the blood and tissues of the body. The third, is to sustain the cardiac, respiratory, and vasomotor nerve-functions, and to pre serve the integrity of the corpuscular ele ments of the blood and tissue through the second week and until convalescence is fully established. In fulfilling the first of these indications, in addition to the constant supply of fresh air and the maintenance of strict cleanliness, includ ing the prompt removal from the room of all evacuations, careful attention should be given to the ingesta—food and drink. The best and only drink proper should be good, cool water given in small quantity at once, but repeated often enough to help in keeping the mouth moist and in encouraging the natural excretions, without overloading the stomach. For nourishment, good fresh milk containing 1 ounce of fresh lime water to 6 ounces of the milk, given in doses of 1 or 2 ounces every two or three hours until the fever reaches its climax from the third to the fifth day, after which it may be moderately increased and often supplemented by 2 or 3 ounces of beef- or mutton- broth salted as much as a well person would relish, given be tween the doses of the milk. If diar rhoea supervenes during the middle or later stage of the disease, a properly pre pared thin wheat-flour and milk-gruel or porridge may take the place of the milk and lime-water with advantage.