Page:EB1911 - Volume 20.djvu/835

 somewhat like the bacillus coli communis, but with a less luxuriant growth. This organism, when taken from young broth cultures twelve to twenty-four hours old—during the period at which flagella are best seen—and examined microscopically, exhibits very lively movements. When, as pointed out by Gruber and Durham, blood-serum, in certain dilutions, from a case of typhoid fever is added to such a culture, the broth, at first turbid, owing to the suspended and moving microorganisms, gradually becomes clear, and a deposit is formed which is found to be made up of masses or clumps of typhoid bacilli which have lost their motility. This reaction is so characteristic and definite, that when the mixture is kept under e.lamination under the microscope, it is quite possible to follow the slowing-down movement and massing together of the organisms. It is found, moreover, that normal diluted blood serum has no such effect on the bacilli. This property of the blood-serum is acquired at such an early date of the disease sometimes even at the end of the first week—and occurs with such regularity, that typhoid fever may now actually be diagnosed by the presence or absence of this “agglutinating” property in the blood. If serum taken from a patient supposed to be suffering from typhoid fever, and diluted with saline solution to 1 in 10, to 1 in 50, or in still greater dilution, causes the bacilli to lose their motility and to become aggregated into clumps within an hour, it may be concluded that the patient is suffering from typhoid fever; if this agglutination be not obtained with a dilution of 1 in 10, in from 15 to 30 minutes, experience has shown that the patient is not suffering from this disease. Certain other diseases, such as cholera, give a similar specific serum reaction with their specific organisms. These sera have, in addition, a slight common action—a general agglutinating power—which, however, is not manifested except in concentrated solutions, the higher dilutions failing to give any clumping action at all, except with the specific bacillus associated with the disease from which the patient, from whom the serum is taken, is suffering.

Mediterranean or Malta Fever.—Until comparatively recently, Mediterranean fever was looked upon as a form of typhoid fever, which in certain respects it resembles; the temperature curve, however, has a more undulatory character, except in the malignant type, where the temperature remains high throughout the course of the attack. According to Hughes, this disease is widely distributed in the countries bordering upon the Mediterranean south of latitude 46° N., and along the Red Sea littoral. Analogous forms of fever giving a “specific” serum reaction with the micro coccus of this disease are also met with in parts of India, China, Africa and America.

This organism is distinctly pathogenetic to monkeys, and its virulence may be so increased that other animals may be affected by it. Though unable to live in clean or virgin soil, it may lead a saprophytic existence in soil polluted with faecal matter. Hughes maintains that the “virus” leaves the body of goats and of man along with the faeces and urine. The importance of this in ambulatory cases is very evident, especially when it is remembered that goats feeding on grass, &c. which has come in contact with such urine are readily infected. It seldom appears to be carried for any considerable distance. Infection is not conveyed by the sputum, sweat, breath or scraping of the skin of patients, and infected dust does not seem to play a very important part in producing the disease. Hughes divides the fever into three types. In the malignant form the onset is sudden, there are headache, racking pain over the whole body, nausea and sometimes vomiting; the tongue is foul, coated and swollen, and the breath very offensive; the temperature may continue for some time at 103° to 105° F. The stools in the diarrhoea which is sometimes present may be most offensive. At the end of a few days the lungs become congested and pneumonia, the pulse weak, hyperpyrexia appears, and death ensues. A second type, by far the most common, is the “undulatory” type, in which there is remit tent pyrexia, separated by periods in which the patient appears to be improving. These pyrexial curves, from one to seven in number, average about ten days each, the first being the longest,—eighteen to twenty-three days. In an intermittent type, in which the temperature-curve closely resembles the hectic pyrexial curve of phthisis or suppuration, the "undulatory" character is also marked. A considerable number of toxic symptoms make their appearance—localized neuritis, synovitis, anaemia, emaciation, bronchial catarrh, weakness of the heart, neuralgia, profuse night-sweats and similar conditions. Patients otherwise healthy usually recover, even after prolonged attacks of the disease, but the mortality amongst patients suffering from organic mischief of any kind may be comparatively high. The diagnosis from malaria, phthisis, rheumatic affections and pneumonia may, in most cases, be made fairly easily, but the serum agglutinating reaction (first demonstrated by Wright in 1897) with cultures of the Micrococcus mcliiensis, corresponding to the typhoid reaction with the typhoid bacillus, is sometimes the only trustworthy feature by which a diagnosis may be made between this fever and the above-mentioned diseases. About 50% of the goats in Malta give a positive agglutinative reaction and about 10% excrete milk which contains the micro coccus.

Sir David Bruce, in his investigations on the tsetse fly disease, pointed out that certain wild animals although apparently in good health might serve as reservoirs for, or storehouses of, the N’gana parasite. He was therefore quite prepared to find