WILDLIFE ZOONOSES FOR THE VETERINARY PRACTITIONER
RUNNING TITLE: WILDLIFE ZOONOSES
Jonathan Sleeman, VetMB, Dipl. ACZM, MRCVS
Wildlife Veterinarian, Virginia Department of Game and Inland
4010 West Broad Street
Richmond, VA 23230
Tel: (804) 367 9492
Fax: (804) 367 9495
There is increasing concern regarding wildlife zoonoses. It is
important that veterinarians are able to give their clients and
the general public appropriate advice regarding the potential
risks, what to do in the event of potential exposure, early recognition
of the signs of wildlife zoonotic infections, and practical advice
to prevent or reduce exposure to wildlife zoonotic pathogens.
This advice is summarized for a variety of wildlife zoonoses in
North America including rabies, hantavirus, tularemia, plague,
psittacosis, baylisascaris, alveolar echinococcosis, arthropod-borne
encephalitis, tick-borne diseases, and food safety related to
Keywords: Disease prevention, North America,
Zoonotic infections are diseases that occur primarily
in wild and domestic animals that can be transmitted to humans.
Infectious pathogens that originate in wildlife have become increasingly
important in recent decades.1,2 The emergence and re-emergence
of these wildlife zoonoses is associated with a range of casual
factors, most of them as a result of human activities such as
increasing human populations, global human travel and trade of
wildlife, changing land use patterns, and other environmental
changes. Veterinarians are often considered a source of information
by the general public as well as clients on all topics relating
to animal health and zoonotic diseases. While all persons who
feel they have been exposed to a zoonotic pathogen should be immediately
referred to his or her health care provider so that a diagnosis
can be made and the correct treatment prescribed, it is important
that veterinarians are able to give advice regarding the potential
risks, what to do in the event of exposure, assist in early recognition
of disease as well provide information to help prevent exposure.
There are many excellent reviews of wildlife zoonoses (see bibliography)
and the intent of this article is not to repeat this work, but
to synthesize practical information and advice that veterinary
practitioners can give to their clients and the general public
regarding measures that can be taken to prevent or reduce exposure
to zoonotic pathogens. If more detailed information is required
the reader is referred to the bibliography and websites at the
end of the article.
Rabies is an acute encephalomyelitis caused by
viruses belonging to the genus Lyssavirus in the family Rhabdovirus.
It is one of the oldest recognized infectious diseases and has
a global distribution except for Antarctica. The Lyssavirus genus
contains at least seven antigenically distinct viruses which are
maintained in different reservoir hosts. Within each serotype
or genotype there are also a number of variants that are also
maintained by different hosts. All mammals are considered susceptible;
however, terrestrial carnivores and bats are the major reservoirs.
The major terrestrial reservoir species in North America are the
raccoon (Procyon lotor), skunks (Mephitis mephitis and other species),
foxes, (Vulpes vulpes, Urocyon cinereoargenteus, and Alopex lagopus)
and coyote (Canis latrans). These species are responsible for
maintaining distinct rabies strains in various geographic regions
of North America (Figure 1). In contrast, rabies in insectivorous
bats, caused by several bat-adapted strains of rabies, occurs
throughout the continental United States.
Rabies virus is shed in the saliva and is usually introduced by
a bite wound. Rare forms of transmission include a contaminated
scratch or wound, mucous membrane exposure, aerosol, laboratory
accident or organ transplantation.3 Incubation is variable, but
is usually less than 3 months. The clinical course of the disease
is short and once clinical signs develop it is invariably fatal.
Animals with rabies will typically have markedly abnormal behavior
which is often classified into two forms. “Dumb” rabies
is characterized by aimless wandering, lethargy, ataxia, hindleg
weakness, paralysis and loss of awareness. Other signs include
pruritis, hyperexcitability, hyperesthesia, photophobia, hypersalivation,
dysphagia, change in phonation and mydriasis. Less frequently
in raccoons “furious” rabies may occur with vicious
attacks on any object and self-mutilation. Both forms ultimately
result in seizures, coma and death.
Rabies is only transmitted when the virus is introduced into bite
wounds, open cuts or onto mucous membranes from saliva or other
potentially infectious material such as neural tissue. People
are usually aware if they have been bitten; however, because bats
have small teeth the bite marks may be small and easily missed.
Consequently, if a person awakens to find a bat in the room, or
if a bat is near a child or mentally impaired or intoxicated person
then rabies exposure should be suspected. Persons who have been
exposed should be advised to wash the wound thoroughly with soap
and water and should be referred to his or her physician and state
or local health authorities. The wild animal suspected of having
rabies should be killed without damage to the brain and placed
in double layered bags for submission to a diagnostic laboratory.
Latex gloves should be worn when handling the carcass which should
be refrigerated. It is vital that the veterinary practitioner
obtain a detailed case history including names and contact information
of persons exposed as well as the identity of any exposed domestic
Diagnosis of rabies in animals is done post mortem using fluorescent
antibody testing on central nervous tissue.
People should be advised to not approach or handle unfamiliar
wild or feral animals especially if they appear friendly. Wild
animals should not be fed, or unintentionally attracted to human
inhabited areas, for example, due to open garbage cans or litter.
People should not bring wild animals into their homes nor try
to nurse sick animals. People should be advised to call animal
control or the local wildlife agency regarding sick, injured or
nuisance wildlife. “Bat proofing” houses and community
buildings may also help prevent exposure. This can be achieved
by caulking or filling any holes that are larger a quarter inch
diameter. Window screens, chimney caps, and draft-guards beneath
doors to attics should be used as well as ensuring that all doors
to the outside close tightly. Attics can be bat-proofed by covering
outside entry points by hanging bird netting or plastic sheeting.
When the bats leave the holes can be permanently sealed. The best
time to bat-proof a home is in the fall and winter as most bats
will leave to hibernate.
Any domestic animal bitten or scratched by either a wild carnivorous
mammal or a bat that is not available for testing should be regarded
as having been exposed to rabies. Unvaccinated dogs, cats, and
ferrets exposed to a rabid animal should be euthanized immediately.
If the owner is unwilling to have this done, the animal should
be placed in strict isolation for 6 months and vaccinated 1 month
before being released. Animals with expired vaccinations need
to be evaluated on a case-by-case basis. Dogs and cats that are
currently vaccinated are kept under observation for 45 days. All
dogs, cats and ferrets should be vaccinated against rabies and
revaccinated according to the Compendium of Animal Rabies Prevention
and Control 2005 produced by the National Association of State
Public Health Veterinarians, Inc; http://www.nasphv.org). Cats
and ferrets should be kept indoors and dogs should be supervised
when outside to minimize the potential for exposure.
Considerable resources are dedicated to controlling rabies in
free-ranging wildlife populations. Currently, the United Stated
Department of Agriculture Animal and Plant Health Inspection Service
Wildlife Services program is distributing oral rabies vaccines
in an effort to create a rabies-free barrier along the Appalachian
ridge by vaccinating raccoons. The vaccine consists of a live
vaccinia vector with a rabies virus glycoprotein spliced into
the vaccinia virus. Although the vaccinia virus is highly attenuated
it does present a remote risk to immunocompromised persons, particularly
those that have skin disease or are pregnant.4 The plastic vaccine
sachets are ice-cubed size and are coated with a sticky, scented
substance. Some are placed inside fish meal polymer baits (Figure
2). The baits have a toll free number (1-877-722-6725) printed
on them for people to call in the event of human or domestic animal
contact. People should be advised not to touch the bait and wash
their hands after handling one. There is no harm from touching
an intact bait. Pet owners should be warned not to attempt to
remove a bait from an animal’s mouth as a bite wound from
an animal that has broken the sachet may result in exposure to
the vaccine. Contact with the liquid vaccine inside the sachet
should be reported to the local health department. In addition,
the exposed area should be washed thoroughly with soap and water.
Vaccine consumption is not harmful to animals, and does not interfere
with the regular rabies vaccination schedule; however, some diarrhea
may develop if multiple baits are consumed.
Pulmonary Syndrome (HPS)
This disease is caused by infection with a variety
of hantaviruses, was first recognized in 1993 in the Southwestern
United States, and this outbreak was later found to be caused
by the Sin Nombre virus. Since then, several pathogenic hantaviruses
have been identified in the United States, and each virus has
a single rodent host. All hantaviruses known to cause HPS are
carried by New World rats and mice of the family muridae, subfamily
Sigmodotinae. The deer mouse (Peromyscus maniculatus) is the host
for Sin Nombre virus. The deer mouse is common and widespread
in rural areas throughout much of the United States. Other hantaviruses
associated with sigmodontine rodents and known to cause HPS include
New York virus, which is hosted by the white-footed mouse (Peromyscus
leucopus); Black Creek Canal virus, which is hosted by the cotton
rat (Sigmodon hispidus); and Bayou virus, which is hosted by the
rice rat (Oryzomys palustris). Nearly the entire continental United
States falls within the range of one or more of these host species.
Early symptoms in humans include fever, headaches, myalgia, nausea,
vomiting, diarrhea, dizziness and chills. Later symptoms include
severe respiratory distress due to pulmonary edema and can be
rapidly fatal. Humans are exposed through the inhalation of aerosolized
rodent urine, feces and saliva as well as handling rodents. Prevention
involves excluding rodents from homes and buildings including
shelters and cabins, watching for signs of rodent infestation
and promptly removing any infestations. Homes should be kept clean
and food covered in rodent-proof containers. Garbage should also
be secured. All entry holes to buildings wider than ¼ inch
should be sealed. Spring-loaded rodent traps and Environmental
Protection Agency (EPA) -approved rodenticides can be used to
reduce infestations. Predators such as non-venomous snakes and
raptors are excellent natural methods to reduce local rodent populations.
Infested areas can be cleaned using 10% bleach solution. Workers
who regularly handle rodents are at increased risk for this disease,
and should contact the Centers for Disease Control and Prevention
(CDC) for more detailed safety precautions (www.cdc.gov).
Tularemia is a serious life-threatening human
disease caused by the bacterium Francisella tularensis. At least
two subspecies are recognized: Francisella tularensis biovar tularensis
(also known as type A) and Francisella tularensis biovar palaeartica
(or type B). Type A is considered the more virulent subspecies.
F. tularensis has one of the broadest host ranges of all bacteria,
but is primarily a disease of lagomorphs and rodents. In North
America, tularemia most commonly involves cottontail rabbits (Sylvilagus
sp., black-tailed rabbits (Lepus californicus), snow shoe hares
(Lepus americanus), beaver (Candor canadensis) and muskrat (Ondatra
zibithecus). Tularemia is highly infectious and can be transmitted
by all known epidemiologic routes including arthropod vectors,
direct contact with infected blood or tissues, through intact
skin or wounds, through ocular mucous membranes, inhalation and
ingestion. Symptoms in people will vary depending on the route
of exposure but include ulceroglandular and glandular syndromes
typified by fever and swollen lymph nodes or oropharyngeal form
typified by pharyngitis and tonsillitis. Typhoidal tularemia presents
with fever, chills, headaches, diarrhea, myalgia, joint pains,
progressive weakness and may be accompanied by bronchopneumonia.
Pneumonia is usually a sequel to inhalation exposure. The practitioner
should advise the general pubic to avoid touching and handling
sick animals, especially lagomorphs and rodents, and wear latex
gloves and wash hands thoroughly after handling animal carcasses.
Game meat should be cooked well (see section on Game Meat). Persons
frequenting areas with arthropod vectors should take the appropriate
precautions (see section on Tick Borne Diseases). Finally, people
should be advised to avoid areas where tularemia is known to be
occurring in wildlife.
Plague is a rare bacterial disease caused by
Yersinia pestis and there is a long history of human outbreaks.
Its importance is illustrated by the fact it is one of very few
international quarantinable infectious diseases of people. It
is flea transmitted and perpetuated by rodents. Infection in humans
results in severe disease with a high case fatality rate. In North
America, plague is mostly confined to the southwestern areas with
most cases reported from New Mexico, Arizona, Colorado and California.
Periodically there are outbreaks among more susceptible species
of rodents such as prairie dogs (Cynomys spp.) and these die-offs
are often the first indication of plague activity in an area.
Public education, particularly for hunters, trappers and other
outdoor recreationists and restriction of activities in areas
with active plague are important preventive strategies. People
should also be advised to not touch dead animals, and make homes
and human-inhabited buildings rodent-proof (see section on Hantavirus
Pulmonary Syndrome). Persons frequently outdoors should take the
appropriate precautions to prevent flea bites (see section on
Tick Borne Diseases). Cats are very sensitive to plague and can
bring infected fleas into homes. Consequently, domestic pets should
be treated for fleas and not allowed to roam freely.
Psittacosis, also known as chlamydiosis or ornithosis,
is due to infection with the intracellular bacteria, Chlamydophila
psittaci. Waterfowl, herons and pigeons are the most commonly
infected wild birds in North America, although it will occasionally
infect gulls and terns, shorebirds, songbirds, and upland gamebirds.
The organism is excreted in feces and nasal discharges and can
remain infective in the environment for several months. It can
be a serious health problem in humans usually causing an atypical
pneumonia. Human infection from wild birds is rare, although persons
who work closely with birds are more at risk. People should avoid
areas with large build up of bird droppings such as rookeries.
Masks and respirators will decrease the possibility of inhaling
airborne avian fecal material in high risk areas. Dry, dusty areas
with bird guano can be wetted down with 5% bleach solution or
other disinfectant. Furthermore, working with large numbers of
birds in dusty, closely confined areas should be avoided.
Baylisascaris procyonis is a large intestinal
roundworm of raccoons (Procyon lotor). It is indigenous in raccoons
in North America and is more common in the Midwestern and Northeastern
United States and along the west coast. The adult worms produce
eggs which are shed in the feces. The larvae develop within the
egg and are infective 2-4 weeks after shedding. People and other
animals become infected when they accidentally ingest the infective
eggs. In these intermediate or aberrant hosts the larvae undergo
aggressive somatic migration. Clinical signs vary depending on
the dose and site of migration but ocular and neural larval migrants
are commonly reported. Larvae migrating in the brain produce traumatic
damage and inflammation resulting in progressive central nervous
system disease. Sources of infection include any areas or objects
contaminated with raccoon feces. Raccoons will often defecate
at latrines which are found at the base of trees, logs, rocks
and other horizontally orientated structures. They are often found
in barns, lofts or garages, on decks, woodpiles, and roofs, and
these areas become important long-term sources of infection. It
appears that young children and developmentally disabled persons
are at highest risk for infection when they spend time outdoors
because of poor hygiene and a propensity for pica and geophagia.
Infection is rare; however, there are an increasing number of
deaths or cases of severe disabling central nervous system disease
To prevent exposure people should be advised to avoid contact
with raccoons and raccoons should not be adopted as pets. Raccoons
should be discouraged from living around homes and parks by preventing
access to food and shelter. Children should be kept away from
known or potentially contaminated areas and taught to recognize
and avoid raccoon latrines. Dealing with contaminated environments
is more problematic because of the resistance of the eggs. Once
in the environment, the eggs can survive for years and they are
resistant to all common disinfectants. Heat is the best method
of killing the eggs. Boiling water, propane flame gun (with the
appropriate care), steam cleaner, autoclave and burning can be
used for contaminated areas. For heavily contaminated areas it
may be desirable to discard the top several inches of soil. Raccoon
feces and contaminated materials should be removed promptly and
burned, buried or sent to a landfill. Gloves and face masks should
be used when handling such material as well as appropriate personal
hygiene measures. Education of people in close contact with raccoons,
for example, hunters, trappers, wildlife rehabilitators and animal
control officers regarding basic personal hygiene and cleanliness
of equipment is also important. Finally persons who suspect they
have been infected should consult a health care provider as early
treatment might reduce serious damage caused by infection.
Red foxes, artic foxes and coyotes are major
definitive hosts for the microscopic tapeworm Echinococcus multilocularis.
The eggs are shed in the feces, and if accidentally ingested by
humans, the larvae develop into large cysts that can destroy the
liver and less commonly lungs, brain and other organs; so called
hydatid cyst disease. If left untreated it can be fatal. E. multilocularis
is found primarily in the north central region of the United States
as well as Alaska and Canada. In these areas, prevalence among
wild foxes and coyotes is high and the prohibition of interstate
transport of these species is an important preventive strategy.
Further advice the veterinary practitioner can give include avoiding
foxes and coyotes and discouraging wild carnivores from coming
close to homes. Dogs and cats should not be allowed to eat wild
rodents as these species are the major intermediate host. As wild
foods such as herbs and berries may be contaminated with the tapeworm
eggs, all wild-picked foods should be washed carefully or cooked
well before eating.
There are a number of arthropod-borne viruses
in North America that cause encephalitis in humans including St.
Louis encephalitis, Eastern (EEE) and Western equine encephalitis,
LaCrosse encephalitis, Jamestown Canyon encephalitis (JCE) and
most recently West Nile virus (WNV). Infection with these diseases
is most often asymptomatic, or results in transient, mild clinical
signs such as fever, headache, nausea, vomiting and lymphadenopathy.
However, rarely mostly older people will develop severe illness
including high fever, neck stiffness, stupor, disorientation,
coma, tremors, convulsions, vision loss and paralysis. The most
severe encephalitis is caused by EEE which can have a case fatality
rate of 50 percent. The arboviruses are maintained in complex
cycles involving different wild vertebrate hosts (birds, rodents
and deer for JCE) and a variety of mosquito species, and humans
will acquire infection through the bite of infected mosquitoes.
The most effective way to avoid WNV and the other arboviruses
is to prevent mosquito bites. People should be advised to use
insect repellent containing an EPA-registered active ingredient.
It is important that the directions on the package are followed.
Many mosquitoes are most active at dusk and dawn and avoiding
outdoor activities during these times is advisable, otherwise
persons should wear long sleeves and trousers. Houses and other
buildings should be mosquito proof including appropriate screens
on doors and windows. Finally, it is advisable to remove potential
mosquito breeding sites by eliminating standing water from flower
pots, buckets, wading pools, blocked gutters and drains, and other
containers including water bowls and bird baths. Holes should
be drilled in any receptacle that could collect water, such as
tire swings, to allow drainage.
There is currently no evidence that WNV can be transmitted directly
through handling infected birds or handling and consuming infected
meat.5 However, people should be advised not to handle wild birds
directly with bare hands. The local health department should be
contacted for advice on reporting and disposing of the carcasses.
Hunters and trappers should wear gloves when handling and cleaning
animals and meat should be cooked thoroughly (see section on Game
There are an increasing number of tick-borne
diseases that appear to be increasing in prevalence in certain
regions of North America. These diseases occur most commonly from
May to September when ticks are most active. Lyme disease is caused
by the spirochete bacterium Borrelia burgdorferi, and is found
most commonly in the northeast from Massachusetts to Maryland
as well as the upper Midwest. Human ehrlichiosis is a recently
recognized tick-borne disease caused by at least two types of
bacteria that infect leukocytes. The distribution of human infections
correlates with the distribution of the tick vectors and human
cases have been reported in the southeast, northeast, upper Midwest
and west coast (Figure 3). For Ehrlichia chaffeensis, the causative
agent of human monocytotrophic ehrlichiosis, white-tailed deer
(Odocoileus virginianus) is the primary reservoir and the geographic
distribution of naturally infected animals was found to be a good
sentinel system for predicting risk for human infection.6 Rocky
Mountain Spotted Fever (RMSF) is caused by the bacterium Rickettsia
ricketsii, and occurs most commonly in the southeastern and southcentral
states. Finally, babesiosis is caused by hemoprotozoan parasites
of the genus Babesia. Babesia microti and Babesia divergens have
been identified in most human cases and occurs most frequently
in the northeast and Midwest.
All these diseases have complex life cycles involving many species
of wild mammals, birds and possibly reptiles as natural reservoirs
for these organisms and different species of ticks as vectors.
Furthermore, white-tailed deer are not important reservoirs for
Lyme disease, but are important in the epidemiology of the disease
as the primary host for adult Ixodes scapularis, which is the
main tick vector in the northeastern, central, and southeastern
Despite the number of tick borne diseases, and the complex epidemiology,
prevention and control is the same for these diseases and relies
on methods to limit exposure to ticks. Ticks prefer wooded and
bushy areas with high grass and leaf litter and people should
be advised to avoid tick-infested areas, especially during May
to September. Insect repellents with 20-30% DEET (n, n-diethyl-m-toluamide)
applied to the skin can be used to prevent tick bites. Use DEET
with caution on children. In addition, permethrins can be applied
to clothing but should not be applied directly to skin. Persons
at risk should be advised to wear long trousers, long sleeves
and socks as well as light colored clothes to help detect ticks
more easily. Eliminating gaps in clothing such as tucking pant
legs into socks can also be helpful. After being outdoors, all
parts of the body should be carefully checked especially haired
areas. Outdoor clothes should be thoroughly washed and dried to
kill any ticks. Ticks should be removed from the body immediately
using fine-tipped tweezers. The tick should be grasped as close
to the skin as possible and pulled upward with steady, even pressure.
The tick should not be jerked or twisted to prevent the mouthparts
remaining in the skin. Ticks should not be handled with bare hands
and care should be taken not to puncture the body. After removing
the tick, the areas should be disinfected and some people may
wish to freeze the tick for later identification should illness
occur within 2-3 weeks. Other community-based methods such as
the application of acaricides and landscape manipulation can be
applied if the risk warrants these more intensive and expensive
measures. Deer movement and population control can also be an
important strategy and this is initiated at a local level in consultation
with the state wildlife agency. However, activities that can artificially
increase deer populations such as feeding should be discontinued.
There are some new tools available such as bait boxes that will
treat wild rodents with an acaricide and they are available from
licensed pest control companies, and research is continuing to
investigate other tick control measures such as treatment of deer
with acaricides and biological control measures.
Finally, it is important to be able to recognize the early symptoms
of these diseases so that medical attention can be sought promptly.
Table 1 summarizes the symptoms of the tick-borne diseases mentioned
Fishing, hunting and trapping of game animals
for food is a popular outdoor activity. Concern over food safety
is no reason not to enjoy wild game meat as it provides healthy
and wholesome food. However, wild game meat has the potential
to cause food-borne illnesses and therefore the practices for
safe food preparation recommended by the US Government should
also apply (http://www.foodsafety.gov/). For example, wild game
meat is one of the most common sources of human Trichinella spp.
infection.7 In addition, an outbreak of Escherichia coli O157:
H7 was traced to jerky made from deer meat.8 Furthermore, there
is concern that handling and consumption of wild game may result
in human exposure to novel microorganisms and the emergence of
new diseases.9 Finally, there is concern about exposure to a variety
of contaminants through the consumption of wild fish and game,
and fish consumption advisories are often issued.10,11 People
should be advised to contact the state health department regarding
current fish consumption advisories. In general for fish it is
advisable to eat smaller, younger fish (within legal limits) as
they are less likely to contain harmful levels of contaminants.
The skin, fat and internal organs should be removed before cooking,
and fish should be cooked in a manner that allows the fat to drain,
for example, by baking, broiling or grilling.
Hunters should avoid killing and consuming wild animals that are
obviously sick. Wild game such as deer and waterfowl should be
promptly eviscerated, taking care to avoid contamination of the
meat with the gastrointestinal contents. The carcass should then
be chilled prior to further preparation. Abscesses and other localized
lesions can be carefully trimmed away; however, hunters should
contact the local state wildlife agency if more generalized pathological
lesions are encountered, or if the meat appears of poor quality.
Bovine tuberculosis has been confirmed in a Michigan hunter (http://www.michigan.gov/mdch)
and illustrates the importance of appropriate hygienic measures,
in particular, wearing gloves during carcass preparation.
Chronic Wasting Disease (CWD) is a progressive, fatal, neurologic
disease of deer and elk. It is caused by an infectious protein
called prions, and is classified in the same group of diseases
as scrapie of sheep and goats, bovine spongiform encephalopathy,
and Creutzfeldt-Jakob disease of humans. Ongoing surveillance,
and at least two detailed epidemiologic investigations,12,13 have
found that there is currently no evidence that CWD has infected
humans, and this is the position of the World Health Organization
(WHO) and the CDC. However, the following advice is given to hunters
to avoid possible exposure:
• Do not shoot, handle or consume any animal that is abnormal
or appears to be sick. If you see a sick deer, please contact
the local state wildlife agency immediately.
• Wear latex or rubber gloves when field dressing the deer
• Bone out meat from the animal. Do not saw through bone
and avoid cutting through the brain or spinal cord (backbone).
• Minimize the handling of brain and spinal tissues/fluids.
• Wash hands and instruments thoroughly after field dressing
• Avoid consuming brain, spinal cord, eyes, spleen, tonsils,
and lymph nodes of deer. Normal field dressing coupled with boning
out a carcass will remove most, if not all, of these body parts.
• If the deer is commercially processed, request that the
animal be processed individually, without meat from other animals
These bullets are adapted from the CWD Alliance website (http://www.cwd-info.org).
Finally, the meat should be stored carefully, protected from vermin
and cooked thoroughly. More details on carcass preparation can
be found on the Pennsylvania Game Commission website (http://www.pgc.state.pa.us).
1. Bengis RG, Leighton FA, Fischer JR, et al:
The role of wildlife in emerging and re-emerging zoonoses. Rev
Sci Tech 23:497-511, 2004
2. Kruse H, Kirkemo A-M, Handeland K: Wildlife as a source of
zoonotic infections. Emerg Infect Dis 10: 2067-2072, 2004
3. Srinivasan A, Burton EC, Kuehnert MJ et al: Transmission of
rabies virus from an organ donor to four transplant recipients.
N Eng J Med 352:1103-1111, 2005
4. Rupprecht CE, Blass L, Smith K et al: Human infection due to
recombinant vaccinia rabies glycoprotein virus. N Eng J Med 345:582-586,
5. Hayes EB: Epidemiology and transmission dynamics of West Nile
virus disease. Emerg Infect Dis 11:1167-1173, 2005
6. Yabsley MJ, Wimberly MC, Stallknecht DE et al: Spatial analysis
of the distribution of Ehrlichia chaffeensis, causative agent
of human monocytotrophic ehrlichiosis, across a multi-state region.
Am J Trop Med Hyg 72:840-850, 2005
7. Roy SL, Lopez AS, Schantz PM: Trichinellosis surveillance-United
States, 1997-2001. MMWR Surveill Summ 52:1-8, 2003
8. Keene WE, Sazie E, Kok J et al: An outbreak of Escherichia
coli O157:H7 infections traced to jerky made from deer meat. JAMA
9. Ahl AS, Nganwa D, Wilson S: Public health considerations in
human consumption of wild game. Ann N Y Acad Sci 969:48-50, 2002
10. Heaton-Jones TG, Homer BL, Heaton-Jones DL et al: Mercury
distribution in American alligators (Alligator mississippiensis)
in Florida. J Zoo Wildl Med 28:62-70, 1997
11. Burger J: Daily consumption of wild fish and game: exposures
of high end recreationists. Int J Environ Health Res 12:343-354,
12. Belay ED, Gambetti P, Schonberger LB, et al: Creutzfeldt-Jakob
disease in unusually young patients who consumed venison. Arch
Neurol 58: 1673-1678, 2001
13. Centers for Disease Control and Prevention: Fatal degenerative
neurologic illnesses in mean who participated in wild game feasts-Wisconsin
2002: MMWR Morb Mortal Wkly Rep 52: 125-127, 2003
Calle PP: Rabies, in Fowler ME, Miller RE (eds):
Zoo and Wild Animal Medicine (ed 5). Philadelphia, PA, Saunders,
Chin J (ed): Control of Communicable Diseases Manual (ed 17).
Washington, DC, American Public Health Association, 2000
Davidson WR, Nettles VF (eds): Field Manual of Wildlife Diseases
in the Southeastern United States (ed 2). Athens, GA, Southeastern
Cooperative Wildlife Disease Study, 1997
Friend M, Franson JC (eds): Field Manual of Wildlife Diseases
General Field Procedures and Diseases of Birds. Madison, WI USGS
Biological Resources Division, 1999
Samuel WM, Pybus, MJ, Kocan AA (eds). Parasitic Diseases of Wild
Mammals (ed 2). Ames, IA, Iowa State Press, 2001
Williams ES, Barker IK (eds). Infectious Diseases of Wild Mammals
(ed 3). Ames, IA, Iowa State Press, 2001
Table 1. Early symptoms of tick-borne diseases found in North
Disease Non-specific signs Rash
(Fatigue, chills, fever, headache, myalgia, swollen lymph nodes)
Lyme disease Yes Yes: Circular rash called erythema
migrans with a bulls eye appearance that expands to 30 cm diameter
(70-80% of patients)
Ehrlichiosis Yes: Including nausea, Rare vomiting,
diarrhea, cough, joint pains, and mental confusion
RMSF Yes: Including nausea, Yes: Macules on wrists,
vomiting, and anorexia forearms and ankles
Babesiosis Yes: Including sweating, None hepatosplenomegaly,
and hemolytic anemia
Figure 1. Geographic distribution of the major
terrestrial reservoirs of rabies in North America (figure courtesy
of the CDC).
Figure 2. Picture of a rabies vaccine laden bait
used to orally vaccinate raccoons and other terrestrial reservoirs
for rabies (picture courtesy of the CDC).
Figure 3. Geographic areas of the United States
where human ehrlichiosis may occur based on the approximate distribution
of the tick vector species North (figure courtesy of the CDC).