The location and character of the bite must be considered.  Bites on the head, neck and hands have been recognized as more dangerous, from early times, and such bites produce fatal results quicker than do bites on other parts of the body, and the reason is largely due to the fact that the other parts of the body are more or less protected by the clothing, and this clothing prevents the entrance of so much poison into the system.  Bites on the head give a high mortality rate and are rapidly fatal.  The close proximity to the brain is one reason.

The part the clothing plays in protection is clearly shown by the following quotation from an eminent authority:  “In India where the natives dress very scantily, the mortality was exceedingly high up to a few years ago, at which time the British introduced the Pasteur laboratories.  The clothing protects the body and it holds back the saliva and can be looked upon as a means of filtering the saliva of the rabid animal, most of the saliva is held back as the teeth pierce the clothing, so that upon entering the flesh the teeth are practically dry, and only a portion of the virus is introduced.  Upon entering the wound this small amount of virus is further diluted by the tissue juices to the non-infectious point.  We know from actual experimental work in the laboratory that the higher dilution will not kill.”

If a portion of the brain of an animal dead from street virus is taken and made up in a dilution of one to five hundred, and this is injected, we find that it does not produce death.  But a dilution of one to three hundred will invariably kill.  This is practically what very often happens when one is bitten through the clothing.  The saliva may be filtered and held back so that a small amount is introduced; perhaps a dilution of one to five hundred of the virus may get into the wound, but this is usually not enough to cause the disease.  There is no possible way of estimating the amount of the inoculation.  In such cases one’s chances of never contracting the disease are only decreased; that is all we can say.

The treating of individuals, bitten by rabid animals, in the Pasteur Institutes, is simply the practical application of results obtained by Pasteur from his original work on rabies virus.  Pasteur was a French chemist living in Paris, and he began his search for the cause and cure of rabies in 1880.  He hoped to find a sure method of preventing the development of the dread disease, even if he could not find a cure for it after it had developed.  While he was pursuing this research Pasteur had access to the cases of rabies in the Paris hospitals, and these numbered sixty each year.  He had practically an unlimited supply, for France could furnish him with twenty-five hundred more mad dogs, and a large number of other animals each year.

[Infectious diseases 245]