STATE OF NEVADA STATE BOARD OF HEALTH CARSON CITY, NEVADA, December 23, 1915. It being manifest to the State Board of Health that rabies is becoming prevalent throughout the State of Nevada and that such condition is rapidly becoming a menace to the health and safety of the people of the State: therefore The State Board of Health urgently recommends to the County Commissioners, the Town Boards of the various towns of the State and the City Councils of the various cities that they immediately pass strict ordinances providing for the muzzling of all dogs, and provide strict penalties for the enforcement of the same. We further recommend that in all cases where possible special officers be detailed for the enforcement of such ordinances. STATE BOARD OF HEALTH, W. D. HOOD, M.D., President. S. L. LEE, M.D., Secretary. RABIES Prepared by the Hygienic Laboratory, R. H. MULLIN, Director INTRODUCTION Rabies, or so-called hydrophobia, has become prevalent in certain parts of the State of Nevada. From the manner in which this disease has spread in other States, it can reasonably be expected that before long, unless active measures of prevention are undertaken, the disease will have spread over the whole of the State of Nevada. Without doubt many people will become exposed to the infection of this disease. This circular has been prepared in order that the citizens of this State will be more or less familiar with the disease and know what precautions to take if any one is bitten or otherwise exposed to an animal supposed to be suffering from the disease. DEFINITION Rabies, or hydrophobia, is an acute infectious disease occurring in human beings and in the lower animals, which terminates fatally. Its spread from animal to animal, or from animal to man, occurs usually by biting, or in some cases by the saliva or "slobbers" of an animal suffering from the disease getting into a fresh open wound. It should be remembered that even a very small wound, such as a scratch, pin prick, or the opening left from a torn hangnail, is large enough to admit the virus of the disease, should it come in contact with such a wound. SUSCEPTIBILITY Man, dogs, cats, cattle, hogs, horses, and in fact all the domestic animals, may become infected. Among wild animals, coyotes, wildcats, rabbits, squirrels, mountain lions, are also subject to the disease. Among domestic animals there are certain misconceptions regarding susceptibility. Some people erroneously believe that pet dogs, thoroughbred dogs, or young dogs do not get the disease as easily as some of the other animals. This idea is entirely wrong; they are just as susceptible; the reason that they are less frequently attacked is that they are probably less often exposed to infection, since they usually receive greater care than do other dogs, and do not run so much at large. It may be taken for granted that all domestic animals and many of the wild ones may be attacked by this disease. SEASONAL INFLUENCES Many people erroneously believe that the disease, rabies, is in some way or other connected with summer heat, and that when summer is over the danger from the disease decreases, and that it is seldom found during the winter months. We often hear the expression "dog days" applied to the warm months of July and August. Nothing could be further from the truth than this supposition. As a matter of fact, the virus of the disease is more rapidly destroyed in the hot sun of summer than in the cold of winter; if it is desired for experimental purposes to preserve the infectiousness of the virus, freezing is frequently resorted to. After exposure to summer sun and drying, in most cases the virus will have lost its capability of producing the disease, particularly if it has been placed in an atmosphere in which there is little, if any, moisture. It is true that during the summer months domestic animals, especially dogs, may become slightly irritable on account of the heat, but this irritability is not connected in any way with the disease, rabies, unless the particular animal has been actually infected from another animal. suffering from the disease. It is also true that during the summer months children are more apt to get the disease, since during this period the schools are not in session and the children ordinarily at school are apt to be on the streets where they may become exposed to dogs or other animals having the disease. PERIOD OF INCUBATION In every infectious or contagious disease there is always a period of time which elapses between the moment when the actual infection takes place and the time when symptoms of the disease develop. This is known as the period of incubation. In human rabies this period of incubation is usually from five to nine weeks. That length of time may elapse after a person is bitten or otherwise infected before symptoms of the disease may appear if one has been actually infected. Some cases have been reported where the symptoms of the disease did not appear until six or seven months after the biting occurred, and in at least one authentic case eleven months elapsed after the biting before symptoms of the disease appeared. However, the usual time is about six weeks. In dogs this period is usually shorter, being from two to five weeks as a rule. Sometimes, however, it may be prolonged to six months or even longer. The length of the period of incubation in wild animals, such as the coyote, is not definitely known, but probably corresponds more or less closely with that occurring in the dog. CAUSE AND DISTRIBUTION The exact cause of the disease has not been found, but from the manifestations of the disease, and from the manner in which it is spread, either accidentally in nature, or experimentally in the laboratory, it has been definitely shown that the disease is one of the so-called "infectious or contagious" diseases. It is spread almost entirely by an animal suffering from the disease biting or otherwise wounding a healthy animal or person. Inasmuch as among animals this is practically the only way in which the disease may be conveyed from one to another, the spread over a large territory is a comparatively slow process which extends gradually, but surely, usually from one district to the one next adjacent. It should be remembered that one of the signs of the disease in animals is the tendency on the part of the rabid animal to run from one place to another. Twenty or thirty miles are known to have been covered by a rabid animal in less than four hours, so that the spread from one community to another may occur in a short time, although the distance separating them is comparatively great. DISTRIBUTION OF THE VIRUS IN THE BODY It has been shown that in a rabid animal the virus of the disease is found principally in the saliva, in the brain and spinal cord, and in the nerves. It is also found in the secretions of some of the glands, such as the lacteal gland which produces milk, and in other parts of the body, but it is in the saliva or "slobbers" and the brain and spinal cord that the virus is found in greatest abundance. Sometimes the question is asked as to whether it is safe to drink milk from a cow which has become rabid, and if it is necessary for a person to take the treatment after having drunk milk from a cow which subsequently showed symptoms of the disease. As a general rule, there is not much danger in drinking milk under such conditions, although it is not advisable. Usually the digestive juices weaken the virus to such an extent that it is incapable of causing the disease in man. The principal danger from milk would be in the case of some injury to the lining membrane of the mouth or stomach which would leave an open wound into which the virus could gain entrance while the milk was being consumed. It is true that animals, such as coyotes or wolves, fighting over a carcass of an animal which has died of rabies, may get some of the virus-bearing brain or spinal cord of the dead animal into wounds obtained during the progress of the fight, and so may become infected, but as a general rule infection through food taken into the stomach does not occur. WHEN MAY A RABID ANIMAL SPREAD THE DISEASE? This is a question that is frequently asked. Obviously one part of the answer would be that a rabid animal is most apt to spread the diseasewhen the symptoms of the disease are present in that animal, but it is also possible for a rabid animal to spread infection before symptoms of the disease appear. It is known that the virus of the disease occurs in the saliva of dogs five or six days before symptoms of the disease appear, so that a person who is bitten by a rabid dog, or other animal, which shows symptoms of the disease within four or five days after the biting has occurred, should consider very carefully the probability of having become infected. It is probable that the virus is not present in such great abundance before the symptoms have appeared as during the actual manifestations of the disease in the animal; nevertheless, danger exists for any individual who has been bitten within a week's time of the appearance of the symptoms in the animal. PROBABILITIES OF HUMAN INFECTION HAVING OCCURRED It should be frankly stated that all persons or animals that have been bitten or otherwise wounded by an animal known to be rabid do not necessarily develop the disease. Only about one person in five or six who have been exposed will develop the disease, even if treatment is not taken. This is due in part to the fact that the danger of being actually infected, when bitten by a rabid animal, varies with the part of the body which is wounded at the time of the attack. Wounds on the head and face are the most dangerous, since these parts are close to the brain and are very plentifully supplied with blood-vessels and nerves along which the virus easily travels. Next in danger comes the hands or any part of the body not protected by clothing. It must be remembered that during the warm months of summer, children are apt to run barefooted, or in many instances without stockings. In such cases the leg or foot which is unprotected by clothing will equal, from the point of view of danger, the hand. Where the biting occurs through clothing, the chances of the individual being infected are considerably less than when unprotected parts are bitten. The reason for this is that, without a doubt, a certain amount of the saliva containing the virus will be rubbed off during the passage of the teeth of the animal through the clothing and so will not gain entrance into the tooth wounds. The greater the thickness of clothing, or bedclothing when one sleeps in the open, which the teeth pass through, and the more it is adapted to absorb the saliva from the teeth as they pass through, the less will the danger of infection be. In animals, probably one animal in every two that are bitten subsequently becomes rabid. Undoubtedly, in some instances the saliva is washed off by the hair of the bitten animal, and so the animal itself is saved from infection. The character of the wound sometimes will affect the probabilities of the individual becoming infected. If the wound bleeds very freely, so as to in effect wash out any of the infectious virus that may have gained entrance, the chances of the individual subsequently developing the disease are not so great as when little, if any, bleeding occurs. Nevertheless, bleeding of the wounds should not be relied on to absolutely protect the individual from becoming infected. COURSE AND SYMPTOMS OF THE DISEASE IN MEN AND ANIMALS It does not seem advisable to describe in detail the course of the disease in the human. All who have seen a case of human rabies are united in the opinion that death from this disease in man is the most horrible that can be imagined. It must be remembered that, once the symptoms of |