PART I.

INFECTIOUS DISEASES.

THE CONTINUED FEVERS.

SIMPLE CONTINUED FEVER.

It is

Definition. Simple continued fever is a fever of two or three days' duration, dependent upon many causes. rarely fatal in temperate climates and is not contagious. This is purely a symptomatic disease: it is not a substantive affection, and it is questioned by many pathologists whether such a disease actually exists. It is not an irritative fever, such as might occur from traumatism, nor is it due to the absorption of pus or other toxemias.

Synonyms.-Febricula; ephemera; synocha; ardent fever of the tropics.

Etiology. There is no specific cause. Extremes of temperature may be said to produce the disease, and it has been claimed that it results from the inhalation of sewer-gas.

Overeating, mental and bodily fatigue, excitement, and violent emotions are supposed to be causative factors. The disease is more common in children than in adults.

Symptoms. The disease rarely begins with marked chill; however, there may be slight chilly sensations; lassitude may occur early; and the temperature may rise to 103° F.; sometimes in children the temperature may be higher than this.

The face is flushed (herpes facialis may occur); the pulse is rapid, full, and bounding; headache, frequently pronounced, is present; often the tongue is coated or furred; and there is loss of appetite. The urine is scanty and highly colored, but

171

rarely contains albumin; the bowels are usually constipated, but there may be diarrhea toward the close of the attack. The patient may either be restless and suffer from insomnia, or he may be dull and drowsy. The disease may terminate suddenly by crisis, or, more rarely, by lysis. The duration of the attack is from a few hours to several days. occurs in the tropics, the symptoms are temperature is much higher, the nervous symptoms are more pronounced, and the malady may be mistaken for sunstroke. Delirium and coma may occur, and the disease may terminate fatally.

When the disease more intense, the

Diagnosis. In the absence of inflammatory conditions and of traumatism, with the presence of the symptoms just enumerated, especially in children, a diagnosis of simple continued fever may be made.

Prognosis. Invariably favorable, except in the severe forms in the tropics.

Treatment. This is purely symptomatic, very little medicine being necessary. Usually, all that is required is, at the onset, a mild purge of calomel, in fractional doses, followed by a saline. Water should be given in moderate amounts; forced feeding is unnecessary, as the disease is a mild one and of short duration. Should the temperature become high and the nervous symptoms prominent, cold sponging or bathing may be beneficial. If the disease occurs in weak or debilitated persons, stimulants-preferably alcohol-should be administered.

INFLUENZA.

Definition. A contagious fever due to a specific cause, the bacillus of Pfeiffer, usually occurring in epidemics, characterized by pronounced catarrh of the mucous membranes, with marked debility, and showing a tendency to inflammatory complications.

Synonyms.-Epidemic catarrhal fever; la grippe.

Etiology. Predisposing Causes.-All races of mankind are susceptible, the disease occurring in every climate and at all seasons. Both sexes are affected, females, however, being more predisposed. One attack increases the liability to others. It is highly infectious and contagious. Epidemics commonly last from eight to nine weeks. Sporadic cases are liable to occur for a long time after the active epidemic has terminated.

The exciting cause is the bacillus of Pfeiffer, which is found in the nasal secretions, sputum, and blood.

Incubation.

The period of incubation varies from a few

hours to two or three days.

Pathology. There is no characteristic lesion. Catarrhal inflammation of the mucous membrane of the respiratory and digestive tract and bronchopneumonia and lobar pneumonia are frequently met with. The specific organism has been found in the lung, liver, spleen, kidney, lymph-glands, membranes of brain, and endocardium, giving rise to inflammatory conditions. (For method of detection of the bacillus see p. 118.)

Symptoms. Since the pandemic of 1889-1890, our knowledge of this disease has materially increased. The varieties and complexity of the symptomatology are so great that an accurate description of this disease is almost impossible. This has led to the classification and arrangement of different varieties, according to the prominence of certain symptoms. The disease begins after a very short period of incubation, generally with no or with ill-defined prodromes, with a pronounced chill followed by fever. Only in exceptional instances does the disease run its course without chill and fever. The range of the temperature is atypical, running from 99° F. to 105° F., rarely above this. The fever generally reaches its acme in the first twenty-four hours; the temperature may, however, rise stepwise, and reach its fastigium only after three or four days. The decline of the temperature also varies, the disease terminating by lysis or crisis; in the greater number of cases, however, the disease may be said to terminate by a form of rapid lysis. During convalescence the temperature may be subnormal. The duration of uncomplicated cases is about from five to seven days. In general terms, the poison of influenza attacks the mucous membrane of the respiratory and digestive tracts. It must, however, be remembered that there are cases that show no catarrhal phenomena; in fact, nothing but fever with rapid pulse, headache, and depression. The lungs may bear the brunt of the affection, although the digestive tract, the cerebrospinal system, or the heart may be the principal seat of the disease. This has led to the classification of four principal varieties: (1) The thoracic variety; (2) the cardiac variety; (3) the gastro-intestinal variety; (4) the nervous variety.

All these varieties show catarrhal symptoms in common, save in those exceptional cases already alluded to.

Then, following the chill and fever, there are pains in the limbs and back, sneezing, coughing (at first unproductive), injected conjunctivæ, pronounced headache, commonly referred to the root of the nose or behind the eyes, occasional vomiting, and diarrhea. Epistaxis is rare.

All these symptoms appear with extreme rapidity. Rashes occasionally occur, such as herpes, urticaria, or erythema. No matter how mild any of the preceding symptoms may be in an individual case, there are always great depression and weakness that are out of proportion to the intensity of all the other phenomena. This is characteristic of influenza. In the majority of cases early enlargement of the spleen may be observed. Cardiac asthenia is a prominent symptom, the pulse being rapid, weak, compressible, and sometimes intermittent. The urine is scanty, highly colored, and rarely contains albumin (toxic), generally without casts.

Complications.-The complications in this disease are extremely numerous. Respiratory complications are the most common the so-called, and not well-understood, influenza pneumonias, bronchopneumonia, croupous pneumonia, and pleurisy, with and without effusion. Otitis media and complications relating to the heart, gastro-intestinal tract, and nervous system occur.

Sequels. The more important sequels are those relating to the heart and lungs. Cardiac asthenia with an intermittent and irregular pulse has frequently been observed. Chronic bronchitis, emphysema, and tuberculosis result. Diabetes and neuralgia, especially of the fifth nerve, are frequent. Anemia, and even pernicious anemia, have been known to follow this affection.

Diagnosis. The diagnosis depends upon the occurrence of an epidemic. The sudden onset, with chill and fever, the marked catarrhal phenomena, the peculiar headache, the intense depression, and the cessation of the symptoms in uncomplicated cases in from five to seven days by rapid lysis or crisis are diagnostic.

Prognosis. In young, robust subjects almost invariably favorable. In the extremes of age, especially in the old suffering from chronic diseases, the prognosis is unfavorable.

Treatment. Rest in bed, even in the mildest cases, is imperative. A laxative dose of calomel or a saline early is followed by good results, even in those cases in which diarrhea is present. For the pains, opium in some form is the most

reliable drug, and Dover's powder or minute doses of morphin are generally employed. The coal-tar products should not be administered on account of their depressing effects upon the heart. If given at all, they should be used cautiously and in very small doses. Diet is not important, as the disease is a brief one, but stimulation should be insisted upon from the onset, especially in old persons or in individuals suffering from some form of chronic ailment.

ENTERIC OR TYPHOID FEVER.

Definition. An acute, specific, infectious disease of from twenty-one to twenty-eight days' duration, due to the bacillus typhosus; it is characterized by fever of a typical range, with gastro-intestinal symptoms, a rose-colored rash, and nervous symptoms. The disease shows constant pathologic lesions.

Synonyms. Typhoid fever; gastric fever; nervous fever; infantile remittent fever; autumnal fever; typhus abdominalis. Description. This disease was first differentiated by Louis in 1829, before this time being usually confounded with typhus fever.

Etiology. Predisposing Causes.—The geographic distribution is wide, the disease prevailing in every country; it is especially prevalent, however, in temperate climates. Autumn months particularly favor the development of enteric fever; often the disease follows hot and dry seasons. The majority of the cases occur between the ages of fifteen and thirty. The sexes are equally affected. Unfavorable hygienic surroundings, such as infected drinking-water, food, sewage, and poor drainage, predispose in susceptible individuals. Insects, especially the common house-fly, may be the carriers of the infective principle. One attack usually confers immunity.

Exciting Cause.-A bacillus discovered by Eberth, known as the bacillus typhosus. (For detection see p. 108.)

Pathology. The cadaveric rigidity is well marked, the body is emaciated, and the typical eruption (rose-colored spots) is not present.

The bacillus, gaining entrance into the gastro-intestinal tract, finds its way through a rupture in the mucous membrane into the lymph-nodes of the submucosa, where inflammatory changes take place. The principal seat of the lesions is the lower part of the ileum, in Peyer's patches, but the solitary lymph-follicles of other parts of the intestinal tract may be