Symptoms.—Certain symptoms give warning of an attack, as headache, lassitude, yawning, restlessness, discomfort in the region of the stomach, and nausea or vomiting. The attack begins with a chilliness or creeping feeling, and there may be so severe a chill that the patient is violently shaken from head to foot and the teeth chatter. Chills are not generally seen in children under six, but an attack begins with uneasiness, the face is pinched, the eyes sunken, the lips and tips of the fingers and toes are blue, and there is dullness and often nausea and vomiting. Then, instead of a chill, the eyelids and limbs begin to twitch, and the child goes into a convulsion. While the surface of the skin is cold and blue during a chill, yet the temperature, taken with the thermometer in the mouth or bowel, reaches 102°, 105°, or 106° F., often. The chill lasts from a few minutes to an hour, and as it passes away the face becomes flushed and the skin hot. There is often a throbbing headache, thirst, and sometimes mild delirium. The temperature at this time, when the patient feels intensely feverish, is very little higher than during the chill. The fever lasts during three or four hours, in most cases, and gradually declines, as well as the headache and general distressing symptoms with the onset of sweating, to disappear in an hour or two, when the patient often sinks into a refreshing sleep. Such attacks more commonly occur every day, every other day, or after intermissions of two days. Rarely do attacks come on with intervals of four, five, six, or more days. The attacks are apt to recur at the same time of day as in the first attack. In severe cases the intervals may grow shorter, in mild cases, longer. In the interval between the attacks the patient usually feels well unless the disease is of exceptional severity. There is also entire freedom from fever in the intervals except in the grave types common to hot climates. Frequently the chill is absent, and after a preliminary stage of dullness there is fever followed by sweating. This variety is known as "dumb ague."
Irregular and Severe Form—Chronic Malaria.—This occurs in those who have lived long in malarial regions and have suffered repeated attacks of fever, or in those who have not received proper treatment. It is characterized by a generally enfeebled state, the patient having a sallow complexion, cold hands and feet, and temperature below normal, except occasionally, when there may be slight fever. When the condition is marked, there are breathlessness on slight exertion, swelling of the feet and ankles, and "ague cake," that is, enlargement of the spleen, shown by a lump felt in the abdomen extending downward from beneath the ribs on the left side.
Among unusual forms of malaria are: periodic attacks of drowsiness without chills, but accompanied by slight fever (100° to 101° F.); periodic attacks of neuralgia, as of the face, chest, or in the form of sciatica; periodic "sick headaches." These may take the place of ordinary malarial attacks in malarial regions, and are cured by ordinary malarial treatment.
Remittent Form (unfortunately termed "bilious").—This severe type of malaria occurs sometimes in late summer and autumn, in temperate climates, but is seen much more commonly in the Southern United States and in the tropics. It begins often with lassitude, headache, loss of appetite and pains in the limbs and back, a bad taste, and nausea for a day or two, followed by a chill, and fever ranging from 101° to 103° F., or more. The chill is not usually repeated, but the fever is continuous, often suggesting typhoid fever. With the fever, there are flushed face, occasional delirium, and vomiting of bile, but more often a drowsy state. After twelve to forty-eight hours the fever abates, but the temperature does not usually fall below 100° F., and the patient feels better, but not entirely well, as in the ordinary form of malaria, where the fever disappears entirely between the attacks. After an interval varying from three to thirty-six hours the temperature rises again and the more severe symptoms reappear, and so the disease continues, there never being complete freedom from fever, the temperature sometimes rising as high as 105° or 106° F. In some cases there are nosebleed, cracked tongue, and brownish deposit on the teeth, and a delirious or stupid state, as in typhoid fever, but the distention of the belly, diarrhea, and rose spots are absent. The skin and whites of the eyes often take on the yellowish hue of jaundice. This fever has been called typhomalarial fever, under the supposition that it was a hybrid of the two. This is not the case, although it is possible that the two diseases may occur in the same individual at the same time. This, indeed, frequently happened as stated, in our soldiers coming from the West Indies during the Spanish-American War—but is an extremely uncommon event in the United States.
Pernicious Malaria.—This is a very grave form of the disease. It rarely is seen in temperate regions, but often occurs in the tropics and subtropics. It may follow an ordinary attack of chills and fever, or come on very suddenly. After a chill the hot stage appears, and the patient falls into a deep stupor or unconscious state, with flushed face, noisy breathing, and high fever (104° to 105° F.). Wild delirium or convulsions afflict the patient in some cases. The attack may last for six to twenty-four hours, from which the patient may recover, only to suffer another like seizure, or he may die in the first. In another form of this pernicious malaria the symptoms resemble true cholera, and is peculiar to the tropics. In this there are violent vomiting, watery diarrhea, cramps in the legs, cold hands and feet, and collapse. Sometimes the attack begins with a chill, but fever, if any, is slight, although the patient complains of great thirst and inward heat. The pulse is feeble and the breathing shallow, but the intellect remains clear.
Death often occurs in this, as in the former type of pernicious malaria, yet vigorous treatment with quinine, iron, and nitre will frequently prove curative in either form.
Black Water Fever.—Rarely in temperate climates, but frequently in the Southern United States and in the tropics, especially Africa; after a few days of fever, or after chilliness and slight fever, the urine becomes very dark, owing to blood escaping in it. This sometimes appears only periodically, and is often relieved by quinine. It is apparently a malarial fever with an added infection from another cause.
Chagres Fever.—A severe form of malarial fever acquired on the Isthmus of Panama, apparently a hemorrhagic form of the pernicious variety, and so treated.
Detection.—To the well-educated physician is now open an exact method of determining the existence of malaria, and of distinguishing it from all similar diseases, by the examination of the patient's blood for the malarial parasite—its presence or absence deciding the presence or absence of the disease. For the layman the following points are offered: intermittency of chills and fever, or of fever alone, should suggest malaria, particularly in a patient living in or coming from a malarial region, or in a previous sufferer from the disease. In such a case treatment with quinine will solve the doubt in most cases, and will do no harm even if the disease be not malaria. Malaria is one of the few diseases which can be cured with certainty by a drug; failure to stop the symptoms by proper amounts of quinine means, in the vast majority of cases, that they are not due to malaria. There are many other diseases in which chills, fever, and sweating occur at intervals, as in poisoning from the presence of suppuration or formation of pus anywhere in the body, but the layman's ignorance will not permit him to recognize these in many instances. The quinine test is the best for him.
Prevention.—Since the French surgeon, Laveran, discovered the parasite of malaria in 1880, and Manson, in 1896, emphasized the fact that the mosquito is the medium of its communication to man, the way for the extermination of the disease has been plain. "Mosquito engineering" has attained a recognized place. This consists in destroying the abodes of mosquitoes (marshes, ponds, and pools) by drainage and filling, also in the application of petroleum on their surface to destroy the immature mosquitoes. Such work has already led to wonderful results.[11] Open water barrels and water tanks prove a fruitful breeding place for these insects, and should be abolished. The protection of the person from mosquito bites is obtained by proper screening of habitations and the avoidance of unscreened open air, at or after nightfall, when the pests are most in evidence. Dwellings on high grounds are less liable to mosquitoes. Persons entering a malarial region should take from two to three grains of quinine three times a day to kill any malarial parasites which may invade their blood, and should screen doors and windows. Patients after recovery from malaria must prolong the treatment as advised, and renew it each spring and fall for several years thereafter. A malarial patient is a direct menace to his entire neighborhood, if mosquitoes enter.