A Rabies Primer
Massachusetts is now in its fourth year of the Mid Atlantic Rabies epidemic (First positive case was discovered on September 16, 1992). During that
time, public awareness and fear about this disease has increased dramatically. Unfortunately, increased awareness has not always translated into increased understanding. This situation has also been the case for PCO’s. This article is an attempt to correct this problem. Rabies is a virus that attacks the nervous system of its victim. Unlike AIDS and Hepatitis, rabies is not transmitted through blood. Nor is it transmitted through urine or feces. This is not to say that the virus cannot be found in these fluids. Rather, the rabies virus is not typically concentrated enough in these fluids to cause disease. Rabies is transmitted through bites because the virus can be carried in the saliva. The biological process is as follows. The victim contracts the virus, usually through a bite or scratch. The virus then multiplies and travels along the nerve tissues until it reaches the brain which has the highest concentration of nerve tissue. Once there, it multiplies enough until the virus starts to shed in the saliva. It is important to realize that an animal can be infected with rabies but not be able to transmit the disease because the virus has not yet shed into the saliva. Unfortunately, we only know this time period between shedding and non-shedding for a few species. For example, if a dog or cat bites you and then doesn’t show signs of rabies within 10 days of the bite, then we know the virus was not in the bite. The dog/cat may still be rabid in that it carries the disease. But the virus has not yet shed into the saliva. As I said before, we only know this time period for a few species. Regrettably, wild species like raccoons are not amongst them. Thus whenever a wild animal bites, it is presumed to be rabid until proven otherwise.
The species most at risk for contracting rabies are raccoons, skunks, foxes, woodchucks, bats and house cats. Any attempt to create hysteria about rabies in squirrels and other animals in the rodent family would be inappropriate. Understand that any mammal or other warm blooded creature can contract and transmit rabies. So be cautious with all of them. However, it would be wrong to say to a customer, “We should remove the squirrels in your attic because they could be rabid”.
Once in the brain the virus manifests itself in two different ways. Furious rabies exists when the animal is voraciously attacking whatever is in its path. This is the rabies symptom that makes headlines. Dumb rabies is the other and more common manifestation. Here the animal is passive and allows people to pet them or come very close. The animal may also appear hurt and in need of help. The key point to realize is that people should never handle animals they are not fully familiar with. In fact, 80 percent of all the people who undergo rabies post exposure vaccinations have initiated the contact with the animal. In other words, the animal didn’t go to them, they went to the animal.
Handling Potential Rabies Suspects
In light of the danger here are a few things to keep in mind. First, no one can visually diagnose a rabid animal. Signs of rabies such as awkward behavior, friendliness, aggressiveness, frothy mouth and slow reactions are also symptomatic of other diseases. Second, time of day isn’t necessarily an accurate warning sign that the animal is sick. For example, raccoons are nocturnal. But just because you see a raccoon walking around during daylight hours doesn’t mean it is rabid. Perhaps a storm is coming and it is trying to fatten up in preparation. Perhaps, I evicted it from a chimney and it needs to find a new home. If the raccoon is acting like it is drunk, injured etc. Then assume it is sick and it needs to be removed. Third, if you remove animals from a yard or inside the house be sure to ask if anyone was exposed. Ask the question repeatedly. People forget that they petted the animal, or the animal nicked them with its teeth. If there has been an exposure the animal should be tested. Take care not to damage the head. ( I will discuss how the head is to be prepared and shipped in another article). Record all the information about the victim, such as name, age, telephone number and address. Have them wash the wound with soap and water. If a pet was exposed find out if the pet was vaccinated for rabies. Don’t rely on the client’s memory. Make sure you see documentation. Finally, call your local health department and get their instructions. If the suspected animal has encountered your pet or any other item, don’t handle those items without wearing latex gloves. You don’t want to risk the possibility of contacting any saliva that may be present on those items. You can disinfect for rabies in a couple of ways. If the temperature is above 70 degrees, you can simply leave the item in the warm air to dry. Leave it alone for at least 24-48 hours. Once something is completely dry it cannot transmit the virus. Otherwise, use a 10% bleach solution mist spray to disinfect. Let the spray remain on the item for at least 15 minutes or until it dries. You want to ensure that the bleach will have enough contact time with the infected area so that it can strip the virus of its protein coat.
Rabies is a serious disease. But like many problems, proper understanding about the disease will help dispel the paranoia that so often accompanies it.
This article originally appeared in Wildlife Control Technology Magazine May/June 1998.