Page:The New International Encyclopædia 1st ed. v. 10.djvu/439

* HYDROPHOBIA. 381 HYDROPHOBIA. been considered distinct, and worthy its own name of rah>c& me ph it tea. A careful considera- tion of all the known facts, however, leads to the conclusion that the disease is one to which all the lower animals, and man also, are liable; that it is protean in its manifestations, chiefly because of the thousand and one cuucumitant circumstances and elements; and that the collected statistics are mostly so tainted, from manifold sources of error, that they need to be scanned and sifted with the utmost discretion and care. It is. how- ever, safer to treat every skunk-bite as though certainly by a rabid animal, since in most cases the facts cannot be known. (The curious will find the question most interestingly discussed in a candid manner in Coues's Fur Bearing Ani- mals.) The nature of the infecting virus is as yet unknown. It is probably found in the saliva. In man there is a variable incubation from three weeks to six months, the period depending large- l_v on the site of the infection. Wounds about the neck and face are especially unfavorable in prognosis; ne.xt are those of the hands. Punc- tured wounds, because of the difficulty of cauter- izing them, are most dangerous. Three stages are described. In the premonitory stage there is pain, numbness, or irritation about the bite. Irritability, nervousness, and depression are com- mon. In the stage of excitement there is great hypersesthesia. Almost any .slight stimulus will cause intense reflex excitability and convulsions. The muscles of deglutition are extremely rigid, or even paralyzed, and any attempt at swallowing may cause spasms of the throat and general con- vulsions ; these may even follow the thought of swallowing. The name hydrophobia is erroneous, and based upon false inferences from these facts. The sutTercr from rabies docs not fear water — ■ he intensely desires it, as he is devoured with thirst, but he cannot swallow it, nor even "go through the motions" of swallowing. There in also a secretion in the throat and mouth of a thick, viscid mucus, with thickened saliva, and the effort to get rid of this with muscles refus- ing to act. causes the bark-like cough and hawk so often described as "barking like a dog.' The patient does not bark, and it is doubtful if he bites. The temperature rises, and the patient may become maniacal. This stage may last from one to four days, and then the paralytic stage supervenes. In this stage the spasms stop, un- consciousness supervenes for the first time, the action of the heart ceases, and the patient dies. The pathological changes found after death from hydrophobi.a are not characteristic. The most constant are found in the nervous system, especially in the region of the medulla oblongata and pons. The changes consist in a varying de- gree of inflammation, marked by small round- cell infiltration of the blood-vessel walls, exuda- tion into the pericellular lymph-spaces, small hemorrhages, and sometimes thrombosis of the small blood-vessels. More recently extensive degenerative changes in the nerve-cells have been described. Lesions have also been noted in the sympathetic, consisting in degeneration of thi> nerve-cells and increase in the thickness of their endothelial capsules. In addition to the changes in the nervous system, there is usually congestion of the mucous membrane of the gastro-intestinal tract and of the pharynx, larynx, and bronchi. Despite the fact that innumerable attempts to discover the cause of the disease have been made without success, it still seems probable that hydrophobia is due to a micro-organism. This organism is not apparently widely distributed throughout the body, but confined mainly to the saliva and the central nervous system. An emul- sion made of the medulla of a rabid animal, injected into dogs, cats, rabbits, guinea-pigs, etc., ' produces symptoms characteristic of the disease, although in rodents there is little or none of the stage of excitement. • Although we have no knowledge as to the spe- cific germ of the disease, hydrophobia furnishes our most remarkable example of the success of artificial immunization by means of protective inoculation. To the French student Pasteur (q.v.) is due the credit not only of the discovery of the preventive treatment of hydrophobia, but of demonstrating through it a principle in thera- peutics which is of constantly widening applica- tion. Pasteur found that he could induce the disease in rabbits by inoculations with portions? of the spinal cords of rabid animals, and that the spinal cords of these rabbits possessed a higU degree of virulence. Drj'ing in air reduced the virulence in direct proportion to the length of the drying. It was found that, while inoculation of man or animals from the fresh rabbit-cords was invariablj' fatal, if the man or animal was first inoculated from one of the cords the virulence of which had been greatly reduced by the drying; and then from cords of gradually in- creasing virulence, he could become so accus- tomed to the virus that injection of the fresh cord would no longer be fatal, and such a series of inoculations made sufliciently soon after the bite of a rabid animal was found to prevent en- tirely the development of the hydrophobia. Ad- vantage is taken of the long period usually elapsing between the bite and the onset of the disease to practice these preventive inoculations, and the result has been a marked decrease in the mortality from the bites of rabid animals. In ew of the uniformly fatal results of hydro- phobia and the success of the Pasteur treatment, the importance of determining at the earliest possible moment whether the animal bj- whom a person has been bitten had rabies can be read- ily appreciated. The animal should not be killed, for as rabies is invariably fatal to canines, the recovery of a sick animal definitely disproves rabies. On the contrary, the animal should be carefully watched, and if it dies, should be sent to a laboratory where examination can he made and the question of rabies definitely settled by inoculation experiments on animals. The treat- ment should be cauterization in every case, less than one hour after the bite, by means of the actual cautery, strong acid, or acid nitrate of mercury. Wounds must be opened by the sur- geon, and even amputation mav be necessary. Washing and syringing wounds with water at 130° F. is desirable. Sucking the wound to draw out the poison has been practiced, and may be safely done if there are no breaks of the mem- brane of the lips or mouth. Administration of morphine or alcohol does harm. Imnumizing by the Pasteur method should be practiced in all cases. By this method the patient is inoculated with attenuated virus by the injection hvpo- dcrmically of emulsion made from the brain of a rabid animal, repeated in stronger and stronger concentration during twenty-one days. The re- sults of the Pasteur method are now indisputable,