Character and Course of the Disease.—Cerebrospinal meningitis is produced by a minute vegetable (bacterium), the Micrococcus intracellularis. This germ does not appear to occur normally in any of the lower animals, nor has it been found in the outer world, and is therefore to be regarded as distinctly a human parasite. It is very fortunately a germ of low vitality, as it develops only at about blood heat, and when expelled from its normal dwelling-place in the human body it dies very quickly.
The accompanying illustration shows how these bacteria appear under the microscope; the drawing was made from fluid taken from the spinal canal of a patient suffering from cerebrospinal meningitis. These germs get within the skull and spinal canal, and produce violent inflammation of the coverings of the brain and cord; these membranes are called “meninges,” hence the name “cerebrospinal meningitis.” Within a short time after their entrance pus is produced, and the condition becomes practically one of abscess around the brain and spinal cord.
In almost all cases the disease is preceded by a slight catarrhal condition of the nose and throat, the symptoms being those of an ordinary cold. The symptoms that point to the covering of the brain being attacked come on with great suddenness; there is usually a chill, followed by intense headache, vomiting, restlessness, with great dread of noises and bright light; in many cases reddish spots appear beneath the skin, and these are usually tender on pressure. In some cases the muscles of the neck become very stiff, and contract so that the head is drawn backward. The temperature is somewhat irregular, but is always above normal in the beginning, and sometimes goes very high; the pulse as a rule is normal, or but little accelerated. After the patient remains in this condition for a period varying from a few hours to several days, he generally becomes unconscious, and in a comparatively short time dies. In some cases the symptoms after starting off very violently quickly subside, and the patient makes a comparatively rapid recovery. In other instances the disease begins more mildly, the patient having more or less of the usual symptoms, but not so severely as is ordinarily the case; in such cases the patient may die, after lingering weeks or months; or may make a protracted recovery, frequently with partial paralytic conditions that permanently remain.
Unfortunately we possess no specific for this disease. Recently there has come into vogue a treatment by a serum supposed to have antitoxic power against this disease, but its exact value is, as yet, by no means settled; it must be used early if any good is to be expected from it. In addition to the antitoxin all that can be done is to keep the patient quiet with anodynes, and to minister to his comfort in every way possible. Ice applications to the head sometimes alleviate the intense headache. As the disease is practically an abscess around the brain and cord, perhaps the most rational treatment would be to open up the skull and let the pus drain away.
Mode of Infection.—As this disease is one that is due to a specific germ it is obvious that it cannot exist without the presence of this organism; the malady is therefore infectious, and must necessarily be to a certain extent contagious, notwithstanding the fact that it is generally thought not to be so. The reason that the affection has not been thought to be contagious may be explained by the following facts: Recent investigation has shown that in many, if not all, instances of this disease, the germ may be found in the nose and throat, where, as has already been explained, it sets up a condition resembling an ordinary cold. In all probability the infection takes place in the nasal cavity first, and the germ ultimately finds its way to the coverings of the brain. Now there is every reason to believe that in many, and probably in a great majority of instances, the germ goes no further than the mucous membrane of the nose, and the patient merely has as a consequence what he considers an ordinary cold. It is clear, however, that if another individual, who was very susceptible to this germ, should contract the disease from this person, he might have the meningeal form of it. In other words, it is probably true that the vast majority of people who are attacked by this organism simply get colds as a consequence, and only now and then does a person get meningitis as a result. This explains why the disease does not ordinarily appear contagious.
The facts above stated are of much importance in combating the spread of this disease. People who are exposed to those having meningitis should be exceedingly careful not to get upon their persons any of the secretions that come from the patient, and during periods of epidemics those who observe a bad cold coming on should promptly consult their physicians, and do everything to prevent the development of all catarrhal conditions in their noses.
During epidemics persons with colds should be very careful not to allow other people to become infected from them. As cold and wet are undoubtedly predisposing causes to colds it is well for everyone to shun such exposure during periods when meningitis is prevalent; debilitating influences, such as alcoholic excess and lack of sleep, should also be avoided.
HYDROPHOBIA.
This disease, as it occurs in man, is practically always conveyed by the bite of some animal, the dog being the usual offender. The poison is present in the saliva of the diseased animal and is transmitted through wounds made by its bite.
As observed in the dog, there are two types of the disease,—one the “furious,” the other the “paralytic.”