FLOWCHART

Diseases / List of Viral Diseases / Disease description:

Rabies (with special reference to Raccoons)

Disease Summary

• Acute viral central nervous system disease. (B58.1.w1)
• Normally a disease of bats and carnivores. (B47)
• Acute fatal viral encephalomyelitis. (B209.1.w1) 
• Rarely recorded in birds: not considered natural reservoirs. Infection has been produced experimentally in geese and ducks and virus has been isolated from ducks.

Alternative Names (Synonyms)

Disease Type

 Viral

Infectious/Non-Infectious Agent (directly associated with the Disease)

• Rabies virus - Rhabdoviridae, an RNA virus (B58.1.w1)

Species/Taxa

• Rhabdoviridae: Rabies virus

Chemical

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Physical

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References

Disease Author

Referee

References

• DIRECTORY- Organisations providing information on Rabies in Raccoons

• The Electronic Library- further reading for "Rabies in Raccoons- Biology and Behaviour" 

Incubation Period, Time Course and Persistence of Disease

The following editorial comment summarises detailed information given within the LITERATURE REPORTS for RABIES IN RACCOONS. Links to the LITERATURE REPORTS are provided at the bottom of this box. Limited data on rabies in general is provided in the literature reports but is not intended to be comprehensive.

1) INCUBATION PERIOD

General:

• The incubation period for rabies is very variable, generally several weeks but varying from a week to a year or longer, depending on the virus strain, host species and the site of inoculation. In humans, periods from less than 10 days to as long as six years have been recorded, but more than half of cases show an incubation period of one to three months. Bites to the head or neck are generally associated with shorter incubation while bites to the extremities produce longer incubation periods.

In Procyon lotor - Common Raccoon

• The incubation period for rabies in raccoons has been recorded to be as short as 10 days and as long as 107 days (based on laboratory studies). From a study of naturally occurring raccoon rabies in raccoons in Ontario, Canada it was suggested that the most usual incubation period might be about five weeks, but with the possibility of both shorter and longer periods.
• For detailed, referenced information on rabies in raccoons see: Rabies - Incubation Period (Disease Reports)

2)  DISEASE DURATION (TO DEATH) IN INDIVIDUAL ANIMALS

• The clinical course for rabies is generally a matter of days - one to 10 days is usual, longer courses are seen occasionally. The prodrome may last one to three days, the furious stage one to seven days (in dogs) and the paralytic stage two to four days. 

In Procyon lotor - Common Raccoon

• While raccoons inoculated with a street rabies virus originating from a dog have sometimes been found dead without prior clinical signs, more usually raccoons with natural or experimental rabies infection have shown clinical signs for periods of less than one day up to 17 days.
• Note: there is little data from recent experiments, since, as part of humane experimental protocols, animals are usually euthanised as soon as definite clinical signs are noticed.
• For detailed, referenced information on rabies in raccoons see: Rabies - Disease Duration (to Recovery) in Individual Animals (Disease Reports)

3) TIME COURSE / PERSISTENCE OF DISEASE IN A SUSCEPTIBLE POPULATION

• Endemic levels of rabies may be maintained in a population for decades. (J128.9.w1)

In Procyon lotor - Common Raccoon

• In endemic areas, raccoon rabies may be maintained in the population for decades, as has been seen in the south-eastern states and in the mid-Atlantic and north-eastern states. However, in a smaller population, the disease is not necessarily maintained indefinitely.
• In general, there appears to be a seasonal pattern to reports of rabid raccoons, with peaks in spring; peaks at other times of year have been less consistent. It has been suggested that the spring peak is associated with the raccoon breeding season. 
• For detailed, referenced information on rabies in raccoons see: Rabies - Time Course-Persistence of Disease in a Susceptible Population (Disease Reports)

• Rabies - Incubation Period (Disease Reports) [For rabies in raccoons]
• Rabies - Disease Duration (to Death) in Individual Animals (Disease Reports) [For rabies in raccoons]
• Rabies - Time Course-Persistence of Disease in a Susceptible Population (Disease Reports) [For rabies in raccoons]

Mortality / Morbidity / Susceptibility / Life stage affected

1)  NUMBER OF DEATHS

• There is a very high fatality rate for individuals showing clinical signs of rabies. However, not all individuals die after either natural or artificial exposure to the virus. The outcome of exposure may be affected by factors such as the virus strain, dose, route and site of exposure (e.g. greater mortality following inoculation into the head or neck), and species exposed.
• For Procyon lotor - Common Raccoon:
  • Raccoons may be infected by both raccoon rabies and other strains of rabies virus, and this infection can be fatal. However, it is also apparent, both from  experimental studies and from the prevalence of seropositive raccoons in wild populations, that rabies infection in raccoons is not always fatal and that raccoons may encounter rabies virus, seroconvert, but not develop fatal illness. Experimental evidence suggests that raccoons have intermediate susceptibility, with higher resistance than foxes or skunks but lower resistance than Didelphis virginiana - Virginian opossum.
  • Rabies is acknowledged as one of the two diseases which may affect raccoons on a population level, the other being canine distemper (Canine Distemper).
  • Detailed information, referenced is provided in the literature reports linked below.

2) NUMBER OF ANIMALS AFFECTED

• The occurrence of rabies is variable. Worldwide in humans it is estimated that there may be 35,000 to 50,000 or even 100,000 cases annually. In the developing world, rabies in dogs is often a serious problem, while in the developed world, rabies in dogs is controlled and rabies is seen mainly in wild carnivore reservoirs and bats. For example, in the USA in 2004 there were 6,836 confirmed cases in nonhuman animals and eight cases in humans.
• Procyon lotor - Common Raccoon
  • Raccoons may be infected by both raccoon rabies and other strains of rabies virus, and this infection can be fatal. However, it is also apparent, both from experimental studies and from the prevalence of seropositive raccoons in wild populations, that rabies infection in raccoons is not always fatal and that raccoons may encounter rabies virus, seroconvert, and not show illness (or death).
  • Detailed information, referenced is provided in the literature reports linked below.

3) EFFECTS OF AGE, SEX AND PHYSIOLOGICAL STATUS

• Susceptibility to rabies infection may be affected by the age, sex and physiological status of the exposed animal. Young animals may be more susceptible than adults. Antibody titres do not directly correlate with protection against infection, since other immunological factors also play a role in preventing rabies. 
• In Procyon lotor - Common Raccoon
  • It is not known whether male or female, adult or juvenile raccoons are more susceptible to rabies. Percentage of different classes of raccoons positive for rabies in different epidemiological studies have varied.
  • In general, raccoons with high levels of serum neutralising antibodies appear more able to survive challenge with lethal street rabies (either raccoon rabies or other rabies strains) than raccoons with only low levels of antibodies, or without antibodies. However, the relationship between serum neutralising antibody titre and resistance to rabies virus is not exact: in some vaccination experiments, some raccoons with relatively low titres have survived challenge while other individuals with relatively high titres have succumbed to challenge.
  • Detailed information, referenced is provided in the literature reports linked below.

4) EFFECTS OF BODY CONDITION AND OTHER DISEASES

• Genetic factors are recognised as affecting susceptibility to rabies.
• Reactivation of rabies virus infection may occur due to stress.
• In Procyon lotor - Common Raccoon
  • It is possible that raccoon susceptibility to rabies may be increased by stress and by concurrent disease.

• Rabies - Mortality Rate (Percentage of the Species Population that die) (Disease Reports) [For rabies in raccoons]
• Rabies - Morbidity Rate (Percentage of the Species Population that develop clinical disease) (Disease Reports) [For rabies in raccoons]
• Rabies - Life Stage Affected (Age, Sex, Physiological Status) (Disease Reports) [For rabies in raccoons]
• Rabies - External Susceptibility Factors (Concurrent Disease, Immunosupression) (Disease Reports) [For rabies in raccoons]

Clinical Signs (by physiological system)

The following editorial comment summarises detailed information given within the LITERATURE REPORTS for RABIES IN RACCOONS. Links to the LITERATURE REPORTS are provided at the bottom of this box. Limited data on rabies in general is provided in the literature reports but is not intended to be comprehensive.

• Most signs of rabies are neurological. "Most of the clinical signs of rabies are expressions of impaired neuronal function (altered neurotransmission) in the CNS. the mechanisms involved are largely unknown." (J214.187.w1)
• Prodromal stage
  • This stage is not usually observed in wild animals but is well recognised in humans and may be seen in closely observed pets. It involves vague changes in temperament (e.g. restlessness, increased nervousness or loss of fear, hyperactivity), and other nonspecific signs such as inappetance, dysphagia, vomiting, diarrhoea and pyrexia.
• Furious form
  • The furious form involves general excitative signs with hyperaesthesia to stimuli (auditory, visual and tactile), ataxia/incoordination, "staring" eyes, sudden and apparently unprovoked agitation and aggression to either other individuals or inanimate objects. Often there is abnormal vocalisation. In some species increased sexual activity is seen. Convulsive seizures during this stage may be fatal but generally animals progress from this stage to the paralytic form before death.
• Local signs
  • Some individuals chew at the site of inoculation or at their extremities.
• Paralytic form 
  • The paralytic form of rabies, involving paresis or paralysis, usually follows the furious form but sometimes is seen directly following the prodromal stage. It generally lasts one to two days. This form involves ascending flaccid paralysis and there may be frequent urination or incontinence, tenesmus, constipation, tail flaccidity, jaw paralysis causing inability to eat, but with profuse salivation, and respiratory muscle paralysis causing respiratory distress. Signs may end in convulsions, coma and death
• Rarely, death from rabies occurs without any clinical signs. 
• Rare survivors of clinical rabies may have severe neurological sequelae.

In Procyon lotor - Common Raccoon

• Prodromal signs of reduction or cessation of eating and drinking have been seen in experimental infection.
• Raccoons with rabies often show altered behaviour, such as appearing around human dwellings during daylight or wandering aimlessly, and may appear obviously sick, incoordinated or paralysed. Raccoons with rabies are often reported to be unaggressive but to lose their fear of humans and dogs. Frankly aggressive behaviour is also reported. "Sick" animals may bite when handled.
• In one experiment with a raccoon rabies variant, sudden onset neurological signs were seen including combinations of circling, head-pressing, head-tilt, excess licking, mainly of the genital area and tail tip, and occasional self-mutilation of the limbs or genital area occurred.
• In experimental infections with strains other than raccoon rabies variant, vague signs of depression, anorexia and lethargy, increased alertness or apprehension, aggression, increased vocalisation, excessive friendliness, incoordination and paralysis have all been noted.
• It is possible that more severe clinical neurological signs may be seen in raccoons infected with raccoon rabies variant than in raccoons infected with other rabies variants.
• Note: Individual raccoons without any behavioural signs have also tested positive for rabies.
• The presence of porcupine quills in a raccoon should raise the suspicion of rabies (although not all raccoons with embedded quills are rabid).
• Detailed information, referenced is provided in the literature reports linked below.

• Rabies - Detailed Clinical Signs (Disease Reports)

Clinical Pathology (Testing Samples incl. Serology)

• Antibodies may be detected using tests such as ELISAs or the rapid fluorescent focus inhibition test. Demonstration of the presence of virus neutralizing antibodies indicates that the individual has been exposed to viral antigen, but does not necessarily indicate disease: an individual may be seropositive following vaccination or having developed immunity following natural exposure. In clinical rabies, antibodies usually develop late in the clinical course. 
• For further information on serological tests see: Rabies virus (with special reference to raccoon rabies variant) - Detection and Identification Techniques (Viral Reports)
• Glycosuria may be present in rabid animals.
• Prominent lymphocytic pleocytosis may be detected in CSF.
• Demonstration of rabies virus neutralizing antibodies in the CSF in association with suggestive clinical signs supports a diagnosis of rabies. 
• Rabies may be found in the saliva, including during the days before onset of clinical signs, but may be detected only intermittently.

In Procyon lotor - Common Raccoon

• Antibodies may be detected in the blood of raccoons. Antibodies have been detected in raccoons following survival of experimental rabies infection, prior to death from experimental infection, and in wild raccoons, particularly those captured during or shortly after a rabies epizootic. Repeated sampling has shown the presence of antibodies to be maintained, sometimes for many months.
• It is not known whether raccoons with antibodies to rabies transmit these antibodies to their offspring and whether this is protective. In one experiment with a vaccinia-rabies glycoprotein recombinant vaccine, cubs of females which were vaccinated during pregnancy were born with virus neutralising antibodies. However, it was not known whether this reflected passive transfer of antibodies or transmission of the vaccine virus in utero. 
• Mononuclear pleocytosis of the CSF has been noted in raccoons with rabies. Mild lymphocytic pleocytosis has been seen in raccoons following vaccination and challenge with street rabies virus.
• Rabies virus may be found in the saliva of raccoons both during the period of clinical rabies and shortly before clinical signs develop.
• Infrared thermography can detect rabies infected raccoons (in an experimental setting), even with only mild clinical signs, by the increased temperature of the nose and rostrum.
• Detailed information, referenced is provided in the literature reports linked below.

• Rabies - Detailed Clinical-Pathological Test Findings - Samples (Disease Reports) [For rabies in raccoons]

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Pathological Findings (by anatomical system)

The following editorial comment summarises detailed information given within the LITERATURE REPORTS for RABIES IN RACCOONS. Links to the LITERATURE REPORTS are provided at the bottom of this box. Limited data on rabies in general is provided in the literature reports but is not intended to be comprehensive.

GROSS PATHOLOGY

• There are no pathognomic gross findings
• Externally, there may be fresh or healed bite wounds, and sometimes gross trauma due to self-mutilation. In areas with porcupines, quills may be found in the muzzle of affected animals. There may be an unusual odour, probably related to reduced hygiene in terminal disease.
• In the CNS there may be congestion of meningeal vessels, the brain tissue may appear pinker than usual an there may be mild cerebral oedema.

In Procyon lotor - Common Raccoon

• Normally, there are no gross lesions in raccoons with rabies. Areas of alopecia and skin reddening have been seen in association with excess licking/self mutilation in raccoons in one experiment.
• Detailed information, referenced is provided in the literature reports linked below.

HISTOPATHOLOGY

• Histopathological changes do not reflect the severity of the clinical disease.
• The general CNS findings are those of viral encephalitis, including Perivascular cuffing, vascular congestion, neuronophagia, neuronal degeneration and focal to diffuse gliosis. Lesions may be most severe in the brain stem.
• The presence of Negri bodies is considered pathognomic for rabies, but these are only seen in about 50 - 75% of cases. These are found most commonly in ganglionic cells of the hippocampus and in Purkinje cells of the cerebellum.
• Spongiform lesions may be found in the grey matter, in the neuropil and in neuronal cell bodies of the thalamus and cerebral cortex.
• Spinal and cranial nerve ganglia, particularly the Gasserian ganglia, may show an inflammatory response. 
• Note: There is no visible inflammatory response in the brain of some rabid individuals. (J214.187.w1)

In Procyon lotor - Common Raccoon

• The main affected area is the CNS. The usual finding is of multifocal nonsuppurative encephalitis, bilateral but not necessarily symmetrical, affecting the brain stem, cerebrum and spinal cord, with perivascular mononuclar cell cuffing of blood vessels, multifocal gliosis and, in severely affected areas, neuronal degeneration.
• Outside the CNS, lesions may be found in the Gasserian ganglia, with inflammatory infiltration, mainly mononuclear. 
• Negri bodies are usually visible in the CNS; these may be larger and more numerous in raccoons infected with raccoon rabies variant than in raccoons infected with other rabies variants. Negri bodies may also be found in the Gasserian ganglia and in cells of other ganglia.
• Atypical findings have included:
  • Absence of lesions of rabies encephalitis, in a naturally infected raccoon with concurrent canine distemper virus (CDV) infection (lesions typical of canine distemper virus infection were present);
  • Eosinophilic encephalitis in a raccoon experimentally infected with the canine MD5951 rabies strain; the raccoons had at least three different parasitic infections, which may be relevant in these findings.
• Detailed information, referenced is provided in the literature reports linked below.

ELECTRON MICROSCOPY

• Rod shaped or bullet-shaped virus particles, 180-200 by 75-80 nm, are found most commonly in the CNS and the salivary glands. Neurons which contain matrices may also have large numbers of virus particles budding from the rough endoplasmic reticulum membrane and the plasma membrane. 

VIRUS ISOLATION

• Virus isolation may be carried out using mouse inoculation or in cell culture. (N7.48.w5)
  • See: Rabies virus (with special reference to raccoon rabies variant) - Detection and Identification Techniques (Viral Reports)

In Procyon lotor - Common Raccoon

• In general, rabies virus may be found in the brain and salivary gland of rabid raccoons. However, in two experiments with a virus strain originating in Mexican free-tailed bats Tadrida brasiliensis mexicana, the salivary glands were virus negative. Rabies virus may also be found in other tissues, such as pancreas, adrenal, kidney and spleen, but is found much less consistently in such organs.
• Detailed information, referenced is provided in the literature reports linked below.

• Rabies - Detailed Pathological Findings - (Necropsy-Post Mortem) (Disease Reports) [For Rabies in Raccoons]

Diagnostic Criteria

• Clinical signs are considered characteristic and may allow suspicion, but are not pathognomonic. (B47, B58.1.w1, B209.1.w1)
  • Signs of rabies are not always characteristic, and may vary greatly among different animals. (B417.2.2.5.w1)
• In countries with endemic urban rabies, clinical signs are important for rabies diagnosis. (J21.73.w3)
  • Since signs can be mistaken for other conditions, rabies should be considered in any human patient with neurological signs, and in any animal which has bitten a human. (J21.73.w3)
• In a rabies-endemic area, rabies must be considered in any animal with acute or progressive CNS dysfunction. (J15.23.w4)
• Note: Rabies cannot be discounted as a diagnosis because the animal has been vaccinated: (J15.23.w4)
  • Vaccine failures do occur on occasion, usually in individuals with low antibody titres following vaccination; (J15.23.w4)
  • Vaccination following infection is not always protective. (J15.23.w4)
• Rabies should be considered in any suspected case of encephalitis in mammals, particularly in taxa at high risk of rabies, such as Carnivora and Chiroptera. (B209.1.w1)

• Antemortem diagnosis may be carried out; virus may be detected by skin biopsy, corneal impressions, saliva or CSF collection and swabs of eye, nasal mucosa or throat. A positive result confirms infection but negative findings do not preclude the possibility of rabies infection. (B209.1.w1, B360.10.w10, B360.11.w11, J21.73.w3, J93.36.w2, J98.358.w3)
• In experimental infection, infected raccoons can be differentiated from non-infected raccoons by infrared thermography: the nose and rostrum are at significantly higher temperatures in raccoons with clinical signs (changed from black to white on an infrared thermal image). (J2.37.w1)
• Post mortem examination is required for definitive diagnosis. (B209.1.w1)

The following may be used for rabies diagnosis:

• Light microscopy/Detection of Negri bodies
  • Histological examination of brain sections or impression smears by light microscopy, in particular detection of characteristic Negri bodies, was the standard method of rabies diagnosis for many years. This has been replaced by the direct fluorescent antibody test, but is still used routinely in some developing countries. It has the advantages of requiring little equipment and giving a rapid result (within a couple of hours) but it is much less sensitive than immunological methods, particularly for partially autolysed samples. Additionally, false positive results may occur if nonspecific inclusion bodies are present. The OIE no longer recommends histopathology for the diagnosis of rabies.
• Mouse inoculation test
  • For many years, mouse inoculation was considered the most sensitive way to detect rabies virus. However, it has now been superseded by modern methods for routine diagnosis. Several days are required for a diagnosis by this method. It is still used occasionally to confirm a test result, for example following human exposure to a suspect rabid animal which is negative by other tests. 
• Electron microscopy
  • Examination by electron microscopy can be used to detect viral inclusions (corresponding to Negri bodies) and virus particles. 
• Virus isolation in cell culture
  • Cell culture is not commonly used for virus isolation but can be useful in  cases where immunoflorescence is inconclusive. It can be used for testing saliva and cerebrospinal fluid samples from living individuals as well as for testing brain and salivary gland tissues post mortem. Murine blastoma cells are recommended for cultivation of street rabies strains. Immunofluorescence is used to detect virus antigen in the cultured calls. While a positive cell culture result in a sample from a living animal allows a definite diagnosis of rabies, a negative result in samples from a live animal is not conclusive. A plaque assay has been developed using chicken embryo cells.
• Fluorescent antibody test
  • The direct fluorescent antibody test (FAT) is presently the standard test for rabies virus detection. It is fast and reliable (sensitive and specific) for use on fresh or frozen tissue, and may be used on tissue which is degraded. It can be carried out on histological sections or on impression smears. In large animals, distribution of virus within the CNS may vary considerably and it is important to examine the cerebellum, brain stem and hippocampus using the FAT. Recently, a procedure has been developed allowing the use of FAT on formalin-fixed tissues.
• Immunoperoxidase
  • An immunoperoxidase method, using the streptavidin-biotin complex and polyclonal or polyclonal antibodies may be used for detection of rabies in formalin fixed paraffin embedded tissue sections.
  • Raccoon rabies variant:
    • The monoclonal antibody (mAb) 802-2 was shown in a study to detect rabies antigen in paraffin embedded tissue sections from rabid raccoons. (J3.136.w4)
• Direct rapid immunohistochemical test (dRIT)
  • This test can be used on brain touch impressions and the reaction product is visible under an ordinary light microscope (mangeta inclusions, while the neuronal background is blue). The test allows diagnosis within one hour. It can be used on frozen samples or samples preserved in glycerol, and has a sensitivity similar to that of the direct fluorescent antibody test.
• RT-PCR
  • RT-PCR to detect lyssavirus nucleic acid is not used in routine rabies diagnosis but is useful for confirmation of IFA test results in formalin-fixed or decomposed material unsuitable for virus isolation, and has been used in antemortem diagnosis. This method may be used on samples of brain tissue, saliva or CSF, and may allow detection of very small amounts of viral material, in tissues which are fresh, degraded or fixed.
• NASBA
  • NASBA is able to detect very small amounts of rabies virus RNA and has been used to test the saliva and CSF in humans with clinical illness.

Antibody detection in CSF:

• Demonstration of rabies virus neutralizing antibodies in the CSF, in association with suggestive clinical signs, supports a diagnosis of rabies. (B209.1.w1)
  • Vaccination against rabies does not result in the presence of rabies virus neutralizing antibodies in the CSF. (B209.1.w1)
  • Antibodies are, rarely, found in the CSF of a healthy individual animal; this strongly suggests prior illness with and recovery from rabies. (B209.1.w1)
• In humans, antibodies may be detected in only about 14% of individuals in the first eight days of infection, but positive in about 58% from day nine onward. (J98.358.w3)

Detailed information, referenced is provided in the literature reports linked below.

• Rabies virus (with special reference to raccoon rabies variant) - Detection and Identification Techniques (Viral Reports)

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The following editorial comment summarises detailed information given within the LITERATURE REPORTS for RABIES IN RACCOONS. Links to the LITERATURE REPORTS are provided at the bottom of this box. Limited data on rabies in general is provided in the literature reports but is not intended to be comprehensive.

General

• A variety of other diseases including distemper [Canine Distemper], hepatitis, listeriosis, tetanus, botulism [Avian Botulism] and some parasitic infections as well as some plant and chemical toxins may cause signs similar to those seen in rabid animals.

In Procyon lotor - Common Raccoon: 

• Canine Distemper is the other main disease causing nervous signs in raccoons. 
  • Note: Rabies may occur concurrently with canine distemper (Canine Distemper) therefore diagnosis of distemper does not rule out a diagnosis of rabies without further testing for rabies.
• Other diseases reported in raccoons and which may cause neurological signs include Sarcocystis neurona protozoan encephalitis, toxoplasmosis, West Nile virus infection (West Nile Virus Disease), environmental toxicoses (e.g. ethylene glycol toxicity, lead poisoning, methyl mercury toxicity) and cerebral neoplasia (astrocytoma).
• Detailed information, referenced is provided in the literature reports linked below.

• Rabies - Literature Reports for Similar Diseases (Disease Reports) in Raccoons

Specific Medical Treatment (Antiserum, Antidote, Anti-(viral/bacterial/fungal) etc.)

Treatment of humans after suspected exposure to rabies is aggressive prophylactic treatment. (B47) [see below - prophylactic treatment]

ANTISERUM

• Treatment of humans after suspected exposure includes use of human-origin rabies immune globulin. [see below - prophylactic treatment]

ANTIVIRAL DRUGS

• In 2004, treatment with the antiviral drug ribavirin was used, together with drug-induced coma and mechanical respiration, in the successful treatment of a 15-year-old girl with clinical rabies. (N7.53.w2)

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General Nursing and Surgical Techniques

• In general, animals suspected of having rabies are either euthanased or placed in quarantine; treatment is not applied. (B23.20.w15, B47)
  • For individual animals bitten or scratched by a known or suspected rabid animal, wound care should be provided prior to the animal being quarantined. (B23.20.w15)
• In humans:  In 2004, drug-induced coma and mechanical respiration was used, together with treatment with the antiviral drug ribavirin, in the successful treatment of a 15-year-old girl with clinical rabies. (N7.53.w2)

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• Not applicable for this disease.

• Not applicable for this disease

Vaccination & Prophylactic Treatment

Animals

• Vaccines are administered intramuscularly in the thigh at a single site (unless otherwise specified by the manufacturer). (B47)

• Inactivated vaccines injected intramuscularly appear to be safe and effective in various species. (B58.1.w1)

• Vaccination of domestic cats and dogs is recommended. (B47)

  • Vaccination is commonly used in domestic pets in endemic areas (B58.1.w1).

  • Vaccination should commence at three months of age. (B47)

  • In dogs either modified live virus vaccines or inactivated virus preparations may be used. (B47)

  • Cats should not be vaccinated with modified live virus vaccines as a small proportion may develop vaccine-induced rabies. (B47)

  • Depending on the vaccine boosters may be required annually or every three years. (B47)

• Horses and ruminants can be vaccinated; annual boosters are required. (B47)

• Vaccines can also be used in non-domestic animals. (B101)

• In zoos, vaccination "may be considered for animals that are particularly rare, are valuable, or may have frequent potential contact with free-ranging reservoirs, especially in epizootic areas." Mammals which are candidates for vaccination may be vaccinated at three months old and revaccinated yearly. Previously vaccinated individuals which are overdue for a booster should be given a single dose of vaccine and returned to an annual schedule of vaccination. (B23.20.w15)

  • Vaccines should be used by licenced veterinarians, and administered in accordance with the information on the product label or package insert. Vaccines given by the intramuscular route should be administered in a muscle mass suitable for the volume to be injected, and avoiding adipose tissue depots. (B23.20.w15)

  • "Use of a rabies vaccine with a 3-year duration of immunity should probably be encouraged because of its potency." (B23.20.w15)

    • Information from manufacturers indicates that three-year vaccines provide 90% to 100% efficacy of protection from rabies challenge following a single dose in cats or dogs and challenge studies have shown effective immunity at three years post vaccination. (J14.40.w2)

• Vaccination of wildlife may be used in the control of rabies where wild species are the major vectors.

  • Oral vaccination has been used to control and even eliminate rabies from wild populations in some areas, for example foxes in parts of Europe, using an attenuated SAD-B19 rabies virus strain. (B360.27.w27, J64.7.w4)

  • Trap-vaccinate-release of raccoons, skunks and feral cats was used, in conjunction with trap-and-shoot in core areas around known rabies cases, to control and eliminate an outbreak of raccoon rabies in New Brunswick, Canada. (P102.16.w2)

• Note: In the USA, only one oral vaccine, Raboval V-RG^® vaccinia-rabies glycoprotein recombinant virus vaccine, is licensed for use in wildlife. (J249.111.w2, P21.107.w1, P102.16.w3)

In Procyon lotor - Common Raccoon

• Oral vaccination programmes use Raboval V-RG^® vaccinia-rabies glycoprotein recombinant virus vaccine, 1.8 mL inside a plastic sachet which is placed inside an extruded fishmeal polymer bait. Tetracycline hydrochloride is present in the bait as a biomarker (deposited in bones and teeth). (J4.213.w4, J249.111.w2)
• Raccoons have also been successfully immunised by intramuscular injection of an inactivated vaccine (1 mL of Imrab^® (Rhone-Merieux). (J1.26.w9)
• Note: vaccination is not effective if the animal is already incubating rabies at the time it is inoculated. Additionally, vaccination may fail occasionally. (J1.43.w2) 

Humans

• Vaccination of humans pre-exposure is recommended for individuals in high-risk occupations such as veterinarians, wildlife biologists, animal control officers, animal handlers and laboratory workers involved in rabies diagnosis, research or vaccine production. (B58.1.w1, B209.1.w1)

  • Vaccination for individuals in high-risk occupations involves three doses of a rabies human diploid cell vaccine, given by deep subcutaneous or intramuscular injection into the deltoid region, on a schedule of injections on days 0, seven and 28. Note: injection into the gluteal region may result in a lower antibody response. (J342.95.w1)

  • For individuals travelling to rabies endemic areas, usually a course of two injections is given, two to four weeks apart by deep intramuscular injection, which should be adequate if post-exposure treatment is expected to be readily available. However, a further dose after six to 12 months is recommended for continued potential exposure. (J342.95.w1) 

  • Preexposure vaccination may also be advisable for spelunkers exploring caves with large bat colonies and individuals likely to spend extended periods (30 days or more) in direct contact with mammals in rabies endemic regions where medical care may not be readily available. (B209.1.w1)

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Animals

• Vaccinated animals which have been possibly exposed (e.g. bitten by a suspected rabid animal) should be given a booster vaccination immediately. (B47, B23.20.w15, B336.76.w76)
  • Following re-vaccination, the animal should be observed carefully for any signs of illness which may indicate rabies, for at least 90 days. (B23.20.w15, , B336.76.w76)
  • If e.g. a zoo animal has been previously vaccinated but its vaccinations are out of date, decisions on appropriate actions (re-vaccination and quarantine, quarantine, or euthanasia) must be made on a case basis. (B23.20.w15)
• Post-exposure prophylaxis of naive, unvaccinated animals which have been bitten or scratched either by an animal known to be rabid, or by a wild carnivore or bat which is not available for rabies testing, is not normally practiced. (B23.20.w15)

Humans

Treatment for rabies after suspected exposure is a combination of prophylactic measures:

Treatment of the wound: 

• The wound from a bite from a suspected rabid animal should be immediately flushed and cleaned thoroughly using soap and water followed by application to the wound of either ethanol or a quaternary ammonium compound. (B47) 
• Immediate washing of a bite wound and flushing with soap and water, detergent or water alone is recommended. (B47, B58.1.w1, J63.5.w1)
• All bites and scratches should be immediately washed with soap and water, and irrigated with povidone-iodine solution or another virucidal solution. (N7.48.w4)
• For deep punctures, a catheter should be placed to flush the wound periodically. (B47)
• The wound should not be sutured. (B47)

Administration of (human origin) rabies immune globulin:

• For individuals without prior vaccination:
  • Post-exposure prophylactic treatment with human-origin rabies immune globulin is used in humans bitten by a suspected rabid animal (B47, B58.1.w1).
  • Administration of rabies immune globulin is considered to be the best postexposure prophylactic treatment for individuals without prior vaccination. (B47)
  • Rabies immune globulin should be locally infiltrated into and around the wound site. (B47, J63.5.w1)
  • Up to half of a total dose of 20 IU/kg bodyweight is given in and around the wound, with the remained given intramuscularly. (J342.95.w1)
  • N.B. Individuals who have been vaccinated prior to being exposed should not be given immune globulin due to possible interference with the anamnestic response  to human diploid cell rabies vaccine. (B47)
  • Additionally, following administration of immune globulin, a rabies human diploid cell vaccine is given (see below). (J342.95.w1)

Vaccination:

• Individuals who have not previously been vaccinated are given vaccine on days 0, 3, 7, 14 and 30 after exposure, the first dose being given after administration of immune globulin. (B47, J342.95.w1)
• Individuals who have already been vaccinated and have adequate antibody titres are re-vaccinated, once on day 0 and once again at some point between day 3 and day 7, by deep intramuscular injection into the deltoid region or, for children, on the anterolateral thigh. (B47, (J342.95.w1))
  • This is essential even for individuals with high antibody titres. (B47)
  • Individuals who have been vaccinated previously but have low or negative titres should be treated as if they have not been vaccinated.

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Environmental and Population Control Measures

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• Reduction in population density of wild animal populations, below a threshold necessary for maintenance of the disease in the population, by a variety of lethal methods such as hunting, poisoning or den gassing, has been used to control rabies, particularly when outbreaks have occurred in certain populations. (B58.1.w1, B209.1.w1, B360.26.w26)
• While there have been some successes at rabies control by population reduction, other programmes have been unsuccessful in reducing the population density sufficiently to stop disease transmission. (B209.1.w1, B360.26.w26) 
  • "Control efforts based on reservoir host species depopulation are not ecologically or morally sound and are ineffective." (B336.76.w76)
  • Attempted eradication of a wildlife host species "is impractical, expensive, and has ecological consequences, which are usually difficult to predict reliably." (B209.1.w1)

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• If an unvaccinated dog, cat or ferret has been exposed to a rabid animal (or to a wild carnivore or bat which is not available for testing, and the owner is not willing for it to be euthanased, the animal should be placed in strict isolation for six months. (N7.54.w1)
• A zoo mammal which has not been vaccinated and which has been bitten or scratched either by an animal known to be rabid, or by a wild carnivore or bat which is not available for rabies testing may have its wound treated, then be placed in strict isolation for six months, with careful monitoring for any signs of illness which may indicate rabies. (B23.20.w15)

Quarantine:

• Strict quarantine regulations are effective in preventing introduction of rabies. (B47)
• In the USA, it is recommended that wild-caught animals which are susceptible to rabies should be quarantined for at least six months before being placed on exhibit in zoos. (N7.54.w1)
• "Because of the risk of rabies in wild animals (especially raccoons, skunks, coyotes, foxes, and bats), AVMA, NASPHV and CSTE strongly recommend the enactment and enforcement of state laws prohibiting their importation, distribution, and relocation. (N7.54.w1)

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