| The goals of prevention efforts are to keep people from
becoming exposed to rabid animals in the first place, and to
prevent disease from developing in those people who do have an
exposure to rabies virus. This can be done by: 1) reducing
encounters between humans and potentially rabid animals; 2)
immunizing domestic animals; 3) providing preexposure immunization
to people at high risk for being exposed to rabies; and 4) giving
postexposure preventive therapy to people who -- despite these
other efforts -- may have been exposed to the virus. |
I. Avoid Wild Animals:
Since rabies in this country is primarily a disease of wildlife, an
important element of rabies prevention is avoiding wild animals.
Many bites and scratches that necessitate postexposure therapy
occur when people try to feed or handle a wild animal. Such
activities should be discouraged. Other exposures occur when wild
animals are kept as pets. It is illegal to keep skunks, raccoons,
coyotes, foxes, or bats as pets in Washington. Furthermore,
Washington law prohibits the importation of any such animals into
the state (WAC 246-100-191).
II. Avoid Bats:
Bats are the animal most likely to be rabid in Washington.
Therefore, avoiding bats is essential to reducing the risk of
rabies in humans. Bats should not be picked up or otherwise
handled. However, bats play an important role in our
ecosystem, and it is neither practical nor desirable to try to
eliminate bats from the environment. Rather, effort should be
directed at altering the circumstances in which people are exposed
to bats.
People commonly encounter bats in their houses. Individual bats occasionally enter buildings accidentally, particularly during the spring and fall as they move between roosts. Young bats sometimes become confused and unintentionally end up indoors -- generally in the fall when learning to fly. However, groups of bats may also establish colonies in houses or other buildings. This increases the chances that a person will encounter a bat. Preventing bats from establishing a colony in a building is preferable to trying to exclude them after they become settled, but methods of evicting bats from buildings have been developed.
| Screens: In Washington, where many houses
do not have screens over windows and doors, the first step to take
to reduce the possibility of being exposed to a bat at home is to
put up screens. |
How to keep bats out of your house.
III. Vaccinate Domestic
Animals:
Appropriate vaccination of domestic animals has been central to
the marked reduction in human rabies cases that has occurred in the
United States.
Approved rabies vaccines are currently available for dogs, cats, ferrets, horses, cattle, and sheep. No vaccine is currently licensed for use in dog-wolf hybrids. Although there are no restrictions on vaccinating dog-wolf hybrids, veterinarians should notify the owners of such animals that if the animal bites a person, it will not be considered vaccinated. In Washington, animal rabies vaccines should only be administered by a licensed veterinarian. Sale of rabies vaccine in any other setting is illegal and should be reported to the Washington State Department of Agriculture at (360) 902-1835. While not all localities require that dogs, cats and ferrets be vaccinated, vaccination of these animals should be strongly encouraged.
All licensed animal vaccines available in this country require that a primary dose be given when the animal is at least three months old. All products require a second primary shot one year after the first. Periodic booster doses are necessary for all currently approved animal vaccines. A vaccinated animal must have records documenting primary vaccination and a current booster dose to be considered "fully-vaccinated". For additional details about each vaccine product and dosing schedules, veterinarians should refer to the Compendium of Animal Rabies Prevention and Control which is updated annually by the National Association of State Public Health Veterinarians (and published in the JAVMA).
IV. Preexposure Vaccination of
Humans:
Preexposure vaccination should be offered to all persons whose
activities place them at increased risk for being exposed to the
rabies virus or to potentially rabid animals (such as Washington
veterinarians and their staffs,veterinary students, animal control
personnel, wildlife rehabilitation workers who have frequent and close
contact with bats, laboratory workers doing rabies
diagnostic tests, and others who have frequent and close contact
with wild animals). In addition, preexposure vaccination is
recommended for persons who plan to spend substantial time (e.g.
one month or more) in countries where dog rabies is common
(The Yellow
Book), since postexposure prophylaxis might be delayed
in such places and certain postexposure products -- particularly
human rabies immune globulin (HRIG) -- may not be readily
available. In persons who have already been vaccinated, there is no
need for HRIG.
Preexposure vaccination is given as a series of three injections -- one each on days 0, 7, and 21 or 28. RVA and PCECV should only be given intramuscularly (IM). Preexposure HDCV injections may be given either IM or, using a different formulation at a lower dose, intradermally (ID). In contrast, postexposure vaccine can only be given intramuscularly.
Details about the human vaccines currently licensed in the U.S. are available.
Table 2 provides the most recent ACIP recommendations pertaining to preexposure vaccination.
| Currently in Washington, rabies is very rare in the animal species commonly encountered by veterinarians and their staffs, animal control officials, and wildlife workers. Therefore, in this state, such persons do not require routine serologic testing or routine booster vaccination. |
I. Postexposure Prophylaxis (PEP) of
Humans:
In 2001, postexposure prophylaxis (PEP) became a reportable
condition in Washington State (WAC 246-101). Healthcare providers
should immediately report any PEP treatment on the appropriate form to their local health
department.
In Washington state, PEP is provided by physicians and some nurse practitioners and physician's assistants. Only a few local health departments offer PEP. Providers should know that all PEP products can be obtained within 24 hours directly from the product distributor. Any provider encountering difficulty obtaining PEP products should contact the Communicable Diseases Epidemiology Section at (206) 361-2914 or toll-free at 1-877-539-4344.
There are three components to PEP: 1) local treatment of wounds; 2) provision of passive immunity with purified specific immunoglobulin; and 3) the induction of active immunity with rabies vaccine. All three components are critical to the effective prevention of rabies.
Table 3: Postexposure Prophylaxis Regimens |
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| * Persons who have been previously vaccinated should not receive HRIG. | |||||||||||||||||||||||||||
1) Local treatment of wounds: Immediate and extensive washing of all bite wounds, scratches, or other sites of potential exposure for 10 minutes with soap and water is arguably the most important measure for preventing rabies following an exposure to a rabid animal. Experiments done in animals suggest that thorough and vigorous cleansing to the depth of the wound with a 20% soap solution can reduce the risk of developing rabies by up to 90%13. Tetanus booster vaccine (Td) should be given if indicated.
2) Immunoglobulin Administration: Purified human anti-rabies immunoglobulin (HRIG) provides rapid protection against rabies for one to two weeks after exposure -- while the more lasting vaccine-induced immune response is developing. HRIG should be given to any previously unvaccinated person regardless of their age, type of exposure, or time since exposure. HRIG can be given through the seventh day following administration of the first dose of vaccine but should not be given after this time because it could interfere with the antibody response to the vaccine. HRIG is not given for preexposure prophylaxis. Nor should HRIG be given as part of PEP in a person who has previously been vaccinated with HDCV, RVA, or PCECV or who has a documented rabies antibody titer to any vaccine.
The recommended dose of HRIG is 20 IU/kg body weight (0.06 ml/lb body wt). As much of the dose as is anatomically feasible should be infiltrated in the area around the wound(s). The remaining volume is administered intramuscularly at a site distant from vaccine inoculation, such as the gluteal area. Providers should note that this is a new recommendation14; until recently, the ACIP recommended that only up to half of the HRIG be infiltrated in the area of the wound.
| Adverse Effects of HRIG: HRIG has been associated with very few adverse reactions. Local pain and low-grade fever occur infrequently following HRIG injection. There is no evidence that HIV, hepatitis B, hepatitis C, or other blood-borne infections have ever been transmitted by HRIG in the United States. No fetal abnormalities have been associated with HRIG use during pregnancy. |
3) Vaccine Administration: Primary postexposure immunization with HDCV, RVA , and PCECV is given intramuscularly (IM) in a regimen of five 1-ml doses. The first dose is given as soon after exposure as possible (day 0). The remaining four doses are given on days 3, 7, 14 and 28 following the first dose.
For adults and older children, the vaccine should be injected into the deltoid muscle. For small children and infants, the muscles of the anterolateral thigh can be used. Vaccine should never be given in the gluteal area or in the same anatomical site as HRIG. If an individual misses any vaccine doses during the first two weeks of the regimen, providers should consult the vaccine manufacturer. The schedule should be adjusted to ensure that four doses of vaccine are received during the first 14 days. The fifth dose can be given on day 28. Persons who have already received preexposure prophylaxis still require two booster doses of vaccine on day 0 and day 3.
Details about the human vaccines currently licensed by the United States are available.
| Efficacy of PEP: Rabies postexposure prophylaxis is very effective. No cases of rabies have ever been reported in persons bitten in the United States by laboratory-confirmed rabid animals who were treated with local wound care, HRIG, and at least five doses of HDCV. However, outside the United States there have been at least 13 documented cases of rabies developing in people given modern tissue culture-derived vaccine10. The reasons for these failures are varied, but all involve some deviation from the PEP recommendations. In some instances, local wound care was not done. In others, rabies immunoglobulin was not given. In addition, several individuals in whom the vaccine was administered into the gluteal region (rather than the deltoid as is recommended) subsequently developed rabies. Each of these cases provides a tragic illustration of how important it is to follow the postexposure recommendations exactly. |
Table 4: RABIES IMMUNIZING PRODUCTS, 2002 |
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| Note: If not available locally, all immunizing products can be obtained within 24 hours directly from the distributor. | |||||||||||||||||||||||||||||||
II. Postexposure management of
domestic animals:
Standardized procedures to deal with domestic animals that have
been exposed to a potentially rabid animal (such as a wild,
carnivorous mammal or a bat) are detailed in the Compendium of Animal
Rabies Control. Note that the procedures detailed below
do not apply to animals that have bitten or
otherwise potentially exposed a human to rabies.
The interventions for animals that have potentially exposed a human
to rabies are discussed on page 9 of the Compendium.
Any domestic animal that has been bitten or scratched by either a wild mammal or bat should be considered potentially exposed to rabies. If the bat or wild animal is available for testing, the local health department should be contacted for further recommendations.
If the wild animal or bat that exposed a domestic animal is not available for testing, the appropriate action depends on the species of the potentially-exposed domestic animal, as follows:
Unvaccinated dogs, cats, and ferrets: Euthanizing unvaccinated dogs, cats, and ferrets exposed to a potentially-rabid animal will eliminate the risk of that pet subsequently developing rabies. If the owner is unwilling to have this done, the animal should be placed in strict isolation for six months with no human or animal contact, and vaccinated one month before being released. If the animal develops symptoms consistent with rabies during that time period, it should be euthanized and tested.
Currently vaccinated dogs, cats, and ferrets: Currently vaccinated dogs, cats, and ferrets should be revaccinated immediately, kept under the owner's control, and observed for 45 days. If the animal develops symptoms of rabies during that time period, it should be euthanized and tested.
Dogs, cats, and ferrets with expired vaccinations: Animals with expired vaccinations need to be evaluated on a case by case basis by the local health department with the assistance of the Communicable Disease Epidemiology Section.
Livestock: Currently vaccinated livestock exposed to a potentially rabid animal should be revaccinated immediately and observed for 45 days. Unvaccinated livestock should be slaughtered immediately. If the owner is unwilling to have this done, the animal should be kept under "very close observation" for six months. Additional recommendations relating to the slaughter and sale of livestock exposed to a potentially rabid animal are detailed in the Compendium of Animal Rabies Control. Anyone dealing with unvaccinated livestock should refer to the Compendium for further direction.
Other animals: The local health department should
be contacted for guidance in situations where other animals have been
bitten by a potentially rabid animal.