RABIES.
Synonyms.—Lyssa; hydrophobia.
Definition.—An acute infectious dis ease of animals occasionally communi cated to man, characterized by ex citement, hypermsthesia, deglutitionary spasm, and paralytic weakness; when not specifically treated ending in death, and undoubtedly caused by a specific bacterial poison.
Incubation and period of incubation varies widely in dif ferent cases. It is shorter in children than in adults and in wounds about the face, head, and hands, or uncovered parts, than in the case of injuries received in other parts of the body through the clothing. The severity and character of the wound also influences the time of onset, the symptoms appearing sooner in cases of infection from punctured and lacerated wounds.
The usual incubationary period is four to eight weeks, but it may be, in occasional instances, six months or even a year or more. The wound through which infection takes place has usually healed entirely before any symptom of rabies is apparent, but in some cases, when the disease appears, the wound be comes irritated and again inflamed. Of persons bitten by rabid dogs, only a small proportion-10 to 20 per cent.— become infected.
The early symptoms in man are gen eral nervousness, with irritability, wake fullness, and depression of spirits. There is often headache and vague uneasiness, sometimes slight fever and rapid pulse, and the wound may become painful and the surrounding tissue show perversion of sensation, with some anesthesia. Some slight stiffness about the muscles of the throat is now noted, the voice changes or becomes husky, and swallow ing becomes difficult. Soon great rest lessness and excitement supervene, to gether with general hypermsthesia and abnormal reaction to external impres sions of all kinds, to the extent, so soon as the height of the attack is reached, of causing reflex spasms. These spasms are quite distressing and severe, and in volve particularly the muscles of the larynx, pharynx, and mouth, and are ac companied by a sense of intense dysp ROM Attempts at swallowing or taking water precipitate the violent and painful spasmodic attacks, which fact causes the patient to dread even the sight of water; whence the common name of the disease: "hydrophobia." There is often at this stage some men tal disturbance, greatest at time of the deglutitionary and respiratory spasms, subsiding in the interval. In other cases delusions and hallucinations, with mani acal excitement, may continue through out the attack. In some cases there are
more general convulsive seizures, re sembling, somewhat, those of tetanus. The disease may run its course without rise of temperature, but most cases show some febrile reaction, 100° to 102° being usual. There is oftentimes a copious se cretion of saliva, which, owing to the difficulty in swallowing, is allowed to run from the mouth.
The acute spasmodic stage lasts for a day or two, and is then succeeded by a paralytic stage, in which the patient lies quiet, nearly helpless, confused, and finally unconscious. The heart-action becomes progressively more feeble, the respiration shallow and increased in fre quency, and death ensues.
In man the initial stage of excitement is rarely absent. But in animals its ab sence is the usual rule, the stage of pa ralysis quickly supervening upon the first symptoms of the disease.
Mention should here be made of the so called pscudorabies, or lyssophobia: i.e., the morbid fear of hydrophobia, leading, by the influence of autosugges tion, to a group of nervous and hysterical manifestations closely simulating the true disease. A neurotic person of in herited nervous instability and easily in Iluenced by suggestion is bitten by a dog supposed to be mad; after a variable time and often in direct consequence of having been joked about the danger, or from brooding over the possibility of an attack of the disease, some nervous symptoms paralleling those of rabies ap pear. The subject becomes apprehen sive, despondent, restless, then excited, and exhibits some spasm or a choking sensation in the throat, this being often only a perversion of the frequently-seen globes hystericus. Occasionally convul sive attacks of an hysteroid character occur. The patient exaggerates the danger and protests that he is really go ing mad. Other varied hysterical phe nomena may be present. The attack does not progress, however: there is no disturbance of general health nor of any of the bodily functions, no temperature changes, no weakness, no prostration. The attack lasts for days or weeks and then subsides. Probably no case has ever proved fatal, the alleged fatal cases being instances of true rabies, as, on the other hand, many of the cases of reported recovery from rabies are most likely instances of the pseudal affection.