Topics in Medicine and Surgery Wildlife Zoonoses for the Veterinary Practitioner Jonathan Sleeman, VetMB, Dip. ACZM, MRCVS

Abstract 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 possible exposure, input regarding early recognition of the signs of wildlife zoonotic , and prac- tical 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, , plague, psittacosis, baylisascaris, alveolar echinococ- cosis, arthropod-borne encephalitis, tick-borne diseases, and food safety related to game meat. This is a US government work. There are no restrictions on its use.

Keywords: disease prevention; North America; wildlife; zoonosis

oonotic infections are diseases that occur pri- synthesize practical information and advice that vet- marily in wild and domestic animals that can erinary practitioners can give to their clients and the Zbe transmitted to humans. Infectious patho- general public regarding measures that can be taken gens that originate in wildlife have become increas- to prevent or reduce exposure to wildlife zoonotic ingly important in recent decades.1,2 The emergence pathogens. If more detailed information is required, and reemergence of these wildlife zoonoses are as- the reader is referred to the Suggested Readings and sociated with a range of casual factors, most of them web sites at the end of the article. as a result of human activities such as increasing human populations, global human travel and trade Rabies of wildlife, changing land-use patterns, and other environmental changes. Veterinarians are often con- Rabies is an acute encephalomyelitis caused by vi- sidered a source of information by the general pub- ruses belonging to the genus Lyssavirus in the family lic as well as clients on all topics relating to animal Rhabdovirus. It is one of the oldest, recognized in- health and zoonotic diseases. Although all persons fectious diseases and has a cosmopolitan distribution who feel they have been exposed to a zoonotic except for Antarctica. The Lyssavirus genus contains 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 From the Virginia Department of Game and Inland Fisheries important that veterinarians are able to give advice Richmond, VA 23230 USA regarding the potential risks and what to do in the Address correspondence to: Jonathan Sleeman, 4010 West Broad Street, Richmond, VA 23230. E-mail: Jonathan.Sleeman@ event of exposure, assist in early recognition of dis- dgif.virginia.gov ease, as well as provide information to help prevent This is a US government work. There are no restrictions on its exposure. There are many excellent reviews of wild- use. life zoonoses (see Suggested Readings), and the in- 1557-5063/06/1501-$0.00 tent of this article is not to repeat this work, but to doi:10.1053/j.jepm.2005.11.006

Journal of Exotic Pet Medicine, Vol 15, No 1 ( January), 2006: pp 25-32 25 26 Sleeman

tious material such as neural tissue. People are usu- ally 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 re- ferred to his or her physician and state or local health authorities. The wild animal suspected of hav- ing rabies should be killed without damage to the brain and placed in double-layered bags for submis- Figure 1. Geographic distribution of the major terrestrial reservoirs sion to a diagnostic laboratory. Latex gloves should of rabies in North America (Figure courtesy of the Centers for be worn when handling the carcass, which should be Disease Control and Prevention). refrigerated. It is vital that the veterinary practitioner obtain a detailed case history including names and at least 7 antigenically distinct viruses that are main- contact information of persons exposed, as well as tained in different reservoir hosts. Within each sero- the identity of any exposed domestic animals. Diag- type or genotype, there are also a number of variants nosis of rabies in animals is confirmed postmortem that are also maintained by different hosts. All mam- with fluorescent antibody testing on central nervous mals are considered susceptible; however, terrestrial tissue. carnivores and bats are the major reservoirs. The People should be advised to not approach or major terrestrial reservoir species in North America handle unfamiliar wild or feral animals, especially if are the raccoon (Procyon lotor), skunk (Mephitis me- they appear friendly. Wild animals should not be fed, phitis and other species), fox, (Vulpes vulpes, Urocyon or unintentionally attracted to human-inhabited ar- cinereoargenteus, and Alopex lagopus), and coyote (Ca- eas. People should not bring wild animals into their nis latrans). These species are responsible for main- homes nor try to nurse sick animals. People should taining distinct rabies strains in various geographic be advised to call animal control or the local wildlife regions of North America (Fig 1). In contrast,agency rabies regarding sick, injured, or nuisance wildlife. in insectivorous bats, caused by several bat-adapted “Bat proofing” houses and community buildings may strains of rabies, occurs throughout the continental also help prevent exposure. This can be achieved by United States. caulking or filling any holes that are larger than a Rabies virus is shed in the saliva and is usually intro- quarter-inch diameter. Window screens, chimney duced by a bite wound. Rare forms of transmission caps, and draft guards beneath doors to attics should include a contaminated scratch or wound, mucous be used, and all doors to the outside should be membrane exposure, aerosol, laboratory accident, or closed tightly. Attics can be bat proofed by covering organ transplantation.3 Incubation is variable, but is outside entry points with hanging bird netting or usually less than 3 months. The clinical course of the plastic sheeting. When the bats leave, the holes can disease is short, and once clinical signs develop, it is be permanently sealed. The best time to bat proof a invariably fatal. Animals with rabies will typically have home is in the fall and winter, because most bats will markedly abnormal behavior, which is often classified leave to hibernate. into two forms. “Dumb” rabies is characterized by aim- Any domestic animal bitten or scratched by either less wandering, lethargy, ataxia, hindleg weakness, pa- a wild carnivorous mammal or a bat that is not ralysis, and loss of awareness. Other signs include pru- available for testing should be regarded as having ritis, hyperexcitability, hyperesthesia, photophobia, been exposed to rabies. Unvaccinated dogs, cats, and hypersalivation, dysphagia, change in phonation, and ferrets exposed to a rabid animal should be eutha- mydriasis. Less frequent in raccoons, “furious” rabies nized immediately. If the owner is unwilling to have may occur, with vicious attacks on any object and self- this done, the animal should be placed in strict mutilation. Both forms ultimately result in seizures, isolation for 6 months and vaccinated 1 month be- coma, and death. fore being released. Animals with killed vaccinations Rabies is only transmitted when the virus is intro- need to be evaluated on a case-by-case basis. Dogs duced into bite wounds, open cuts, or onto mucous and cats that are currently vaccinated should be kept membranes from saliva or other potentially infec- under observation for 45 days. All dogs, cats, and Wildlife Zoonoses 27

water. Vaccine consumption is not harmful to ani- mals and does not interfere with the regular rabies vaccination schedule; however, some may develop if multiple baits are consumed.

Hantavirus Pulmonary Syndrome

This disease, caused by with a variety of hantaviruses, was first recognized in 1993 in the Southwestern United States; this outbreak was later found to be caused by the Sin Nombre virus. Since then, several pathogenic hantaviruses have been Figure 2. Picture of a rabies vaccine–laden bait used to orally identified in the United States, and each virus has a vaccinate raccoons and other terrestrial reservoirs for rabies (picture single host. All hantaviruses known to cause courtesy of the Centers for Disease Control and Prevention). hantavirus pulmonary syndrome are carried by New World rats and mice of the family muridae, subfam- ily Sigmodotinae. The deer mouse (Peromyscus man- ferrets should be vaccinated against rabies and re- iculatus) is the host for Sin Nombre virus. The deer vaccinated according to the Compendium of Animal mouse is common and widespread in rural areas Rabies Prevention and Control 2005 produced by the throughout much of the United States. Other han- National Association of State Veteri- taviruses associated with sigmodontine and narians, Inc (http://www.nasphv.org). Cats and knownfer- to cause hantavirus pulmonary syndrome in- rets should be kept indoors, and dogs should be clude New York virus, which is hosted by the white- supervised when outside to minimize the potential footed mouse (Peromyscus leucopus); Black Creek Ca- for exposure. nal virus, which is hosted by the cotton rat (Sigmodon Considerable resources are dedicated to control- hispidus); and Bayou virus, which is hosted by the rice ling rabies in free-ranging wildlife populations. Cur- rat (Oryzomys palustris). Nearly the entire continental rently, the United Stated Department of Agriculture, United States falls within the range of one or more Animal and Plant Health Inspection Service, Wildlife of these host species. Early symptoms in humans Services program is distributing oral rabies vaccines include , , myalgia, nausea, vomiting, in an effort to create a rabies-free barrier along the diarrhea, dizziness, and chills. Later symptoms in- Appalachian ridge by vaccinating raccoons. The vac- clude severe respiratory distress due to pulmonary cine consists of a live vaccinia with a rabies edema, which can be rapidly fatal. Humans are ex- virus glycoprotein spliced into the vaccinia virus. posed through the inhalation of aerosolized rodent Although the vaccinia virus is highly attenuated, it urine, feces, and saliva, as well as the handling of does present a remote risk to immunocompromised rodents. Prevention involves excluding rodents from persons, particularly those who have skin disease or homes and buildings including shelters and cabins, those who are pregnant.4 The plastic vaccine sachets watching for signs of rodent infestation, and are ice-cubed size and are coated with a sticky, promptly removing any infestations. Homes should scented substance. Some are placed inside fish meal be kept clean and food should be covered in rodent- polymer baits (Fig 2). The baits have a toll-freeproof containers.num- Garbage should also be secured. ber (1-877-722-6725) printed on them for people to All entry holes to buildings wider than ¼ inch call in the event of human or domestic animal con- should be sealed. Spring-loaded rodent traps and tact. People should be advised not to touch the bait Environmental Protection Agency-approved ro- and wash their hands after handling one. There is no denticides can be used to reduce infestations. harm from touching an intact bait. Pet owners Predators such as nonvenomous snakes and rap- should be warned not to attempt to remove a bait tors are excellent natural methods to reduce local from an animal’s mouth, because a bite wound from rodent populations. Infested areas can be cleaned an animal that has broken the sachet may result in using 10% bleach solution. Workers who regularly exposure to the vaccine. Contact with the liquid handle rodents are at increased risk for this dis- vaccine inside the sachet should be reported to the ease and should contact the Centers for Disease local health department. In addition, the exposed Control and Prevention (CDC) for more detailed area should be washed thoroughly with soap and safety precautions (www.cdc.gov). 28 Sleeman

Tularemia cation of plague activity in an area. Public education, particularly for hunters, trappers, and other outdoor Tularemia is a serious, life-threatening human dis- recreationists, and restriction of activities in areas ease caused by the bacterium .At with active plague are important preventive strate- least two subspecies are recognized: F. tularensis bio- gies. People should also be advised not to touch var tularensis (also known as type A) and F. tularensis dead animals and make homes and human-inhab- biovar palaeartica (or type B). Type A is considered ited buildings rodent proof (see section on Han- the more virulent subspecies. F. tularensis has one of tavirus Pulmonary Syndrome). Persons frequently the broadest host ranges of all , but is pri- outdoors should take appropriate precautions to marily a disease of lagomorphs and rodents. In prevent flea bites (see section on Tick-Borne Dis- North America, tularemia most commonly involves eases). Cats are very sensitive to plague and can cottontail rabbits (Sylvilagus spp., black-tailed rabbits bring infected fleas into homes. Consequently, do- (Lepus californicus), snowshoe hares (Lepus america- mestic pets should be treated for fleas and not nus), beaver (Candor canadensis), and muskrat (On- allowed to roam freely. datra zibithecus). Tularemia is highly infectious and can be transmitted by all known epidemiologic routes including arthropod vectors by inoculation of Psittacosis skin, ocular or oral mucuus membranes with con- taminated water, blood or tissues, inhalation, and Psittacosis, also known as avian chlamydiosis or orni- ingestion. Symptoms in people will vary depending thosis, is due to infection with the intracellular bac- on the route of exposure, but include ulceroglan- teria Chlamydophila psittaci. Waterfowl, herons, and dular and glandular syndromes typified by fever and pigeons are the most commonly infected wild birds swollen lymph nodes, or oropharyngeal form typi- in North America, although it will occasionally infect fied by pharyngitis and tonsillitis. Typhoidal tulare- gulls and terns, shorebirds, songbirds, and upland mia presents with fever, chills, headaches, diarrhea, gamebirds. The organism is excreted in feces and myalgia, joint pains, and progressive weakness, and nasal discharges and can remain infective in the may be accompanied by bronchopneumonia. Pneu- environment for several months. It can be a serious monia is usually a sequelle to inhalation exposure. health problem in humans, usually causing an atyp- The practitioner should advise the general pubic to ical . Human infection from wild birds is avoid touching and handling sick animals, especially rare, although persons who work closely with birds lagomorphs and rodents, and wear latex gloves and are more at risk. People should avoid areas with wash hands thoroughly after handling animal car- large buildup of bird droppings such as rookeries. casses. Game meat should be cooked well (see sec- Masks and respirators will decrease the possibility of tion on Game Meat). Persons frequenting areas with inhaling airborne avian fecal material in high-risk arthropod vectors should take the appropriate pre- areas. Dry, dusty areas with bird guano can be wetted cautions (see section on Tick-Borne Diseases). Fi- down with 5% bleach solution or other disinfectant. nally, people should be advised to avoid areas where Furthermore, working with large numbers of birds in tularemia is known to be occurring in wildlife. dusty, closely confined areas should be avoided.

Plague Baylisascaris

Plague is a rare bacterial disease caused by Baylisascaris procyonis is a large intestinal roundworm pestis, and there is a long history of human out- of raccoons. It is indigenous in raccoons from North breaks. Its importance is illustrated by the fact it is America and is more common in the Midwestern one of a very few international quarantinable infec- and Northeastern United States and along the West tious diseases of people. It is flea transmitted and Coast. The adult worms produce eggs which are shed perpetuated by rodents. Infection in humans results in the feces. The larvae develop within the egg and in severe disease with a high case fatality rate. In are infective 2 to 4 weeks after shedding. People and North America, plague is mostly confined to the other animals become infected when they acciden- southwestern areas, with most cases reported from tally ingest the infective eggs. In these intermediate New Mexico, Arizona, Colorado, and California. Pe- or aberrant hosts, the larvae undergo aggressive so- riodically, there are outbreaks among more suscep- matic migration. Clinical signs vary depending on tible species of rodents, such as prairie dogs (Cyno- the dose and site of migration, but ocular and neural mys spp.), and these die-offs are often the first indi- larval migrans are commonly reported. Larvae mi- Wildlife Zoonoses 29 grating in the brain produce traumatic damage and datid cyst disease. If left untreated, it can be fatal. E. inflammation, resulting in progressive central ner- multilocularis is found primarily in the North Central vous system disease. region of the United States as well as Alaska and Sources of infection include any areas or objects Canada. In these areas, prevalence among wild foxes contaminated with raccoon feces. Raccoons will of- and coyotes is high, and the prohibition of interstate ten defecate at latrines that are found at the base of transport of these species is an important preventive trees, logs, rocks, and other horizontally orientated strategy. Further advice the veterinary practitioner structures. They are often found in barns, lofts, or can give includes avoiding foxes and coyotes and garages, on decks, woodpiles, and roofs, and these discouraging wild carnivores from coming close to areas become important long-term sources of infec- homes. Dogs and cats should not be allowed to eat tion. It appears that young children and develop- wild rodents, because these species are the major mentally disabled persons are at highest risk for intermediate host. Because wild foods such as herbs infection when they spend time outdoors because of and berries may be contaminated with the tapeworm poor hygiene and a propensity for pica and geopha- eggs, all wild-picked foods should be washed care- gia. Infection is rare; however, there are an increas- fully or cooked well before eating. ing number of deaths or cases of severe disabling central nervous system disease in infants. Arthropod-Borne Viral Encephalitis To prevent exposure, people should be advised to avoid contact with raccoons, and raccoons should not be adopted as pets. Raccoons should be discour- There are a number of arthropod-borne viruses in aged from living around homes and parks by pre- North America that cause encephalitis in humans venting access to food and shelter. Children should including St. Louis encephalitis, Eastern and West- be kept away from known or potentially contami- ern equine encephalitis, LaCrosse encephalitis, nated areas and taught to recognize and avoid rac- Jamestown Canyon encephalitis, and, most recently, coon latrines. Dealing with contaminated environ- West Nile virus (WNV). Infection with these diseases ments is more problematic because of the resistance is most often asymptomatic, or results in transient, of the eggs. Once in the environment, the eggs can mild clinical signs such as fever, , nausea, survive for years, and they are resistant to all com- vomiting, and . However, rarely, mon disinfectants. Heat is the best method of killing immunocompromised and elderly patients will de- the eggs. Boiling water, propane flame gun (with the velop severe illness including high fever, neck stiff- appropriate care), steam cleaner, autoclave, and ness, stupor, disorientation, coma, tremors, convul- burning can be used for contaminated areas. For sions, vision loss, and paralysis. The most severe en- heavily contaminated areas, it may be desirable to cephalitis is caused by Eastern equine encephalitis, discard the top several inches of soil. Raccoon feces which can have a case fatality rate of 50%. The and contaminated materials should be removed arboviruses are maintained in complex cycles involv- promptly and burned, buried, or sent to a landfill. ing different wild vertebrate hosts (birds, rodents, Gloves and face masks should be used when han- and deer for Jamestown Canyon encephalitis) and a dling such material. Education regarding basic per- variety of mosquito species, and humans will acquire sonal hygiene and cleanliness of equipment is also infection through the bite of infected mosquitoes. important for people in close contact with raccoons, The most effective way to avoid WNV and other for example, hunters, trappers, wildlife rehabilita- arboviruses is to prevent mosquito bites. People tors, and animal control officers. Finally, persons should be advised to use insect repellent containing who suspect they have been infected should consult an Environmental Protection Agency-registered ac- a health care provider, because early treatment tive ingredient. It is important that the directions on might reduce serious damage caused by infection. the package are followed. Many mosquitoes are most active at dusk and dawn, and avoiding outdoor ac- tivities during these times is advisable; otherwise, Alveolar Echinococcosis persons should wear long-sleeved shirts and trousers. Houses and other buildings should be made mos- Red foxes, arctic foxes, and coyotes are major defin- quito proof with appropriate screens on doors and itive hosts for the microscopic tapeworm Echinococcus windows. Finally, it is advisable to remove potential multilocularis. The eggs are shed in the feces, and if mosquito breeding sites by eliminating standing wa- accidentally ingested by humans, larvae develop into ter from flower pots, buckets, wading pools, blocked large cysts that can destroy the liver and, less com- gutters and drains, and other containers including monly, , brain, and other organs; so-called hy- water bowls and bird baths. Holes should be drilled 30 Sleeman

rally infected animals was found to be a good senti- nel system for predicting risk for human infection.6 Rocky Mountain is caused by the bac- terium Rickettsia ricketsii and occurs most commonly in the Southeastern and South Central states. Fi- nally, babesiosis is caused by hemoprotozoan para- sites of the genus Babesia. Babesia microti and Babesia divergens have been identified in most human cases and occur most frequently in the Northeast and Midwest. All these diseases have complex life cycles involv- ing many species of wild mammals, birds, and possi- bly reptiles as natural reservoirs for these organisms Figure 3. Geographic areas of the United States where human and different species of ticks as vectors. Further- may occur based on the approximate distribution of the more, white-tailed deer are not important reservoirs tick vector species. Ixodes scapularis and Ixodes pacificus are the for , but are important in the epidemi- main vectors of human granulocytotropic ehrlichiosis. Amblyomma ology of the disease as the primary host for adult americanum is the main vector for human monocytotropic ehrlichio- sis. (Figure courtesy of the Centers for Disease Control and Ixodes scapularis, which is the main tick vector in the Prevention). Northeastern, Central, and Southeastern states. Despite the number of tick-borne diseases and the complex epidemiology, prevention and control are in any receptacle that could collect water, such as the same for these diseases and rely on methods to tire swings, to allow drainage. limit exposure to ticks. Ticks prefer wooded and There is currently no evidence that WNV can be bushy areas with high grass and leaf litter, and peo- transmitted directly through handling infected birds ple should be advised to avoid tick-infested areas, or handling and consuming infected meat.5 How- especially during May to September. Insect repel- ever, people should be advised not to handle wild lents with 20 to 30% DEET (n, n-diethyl-m-tolua- birds directly with bare hands. The local health de- mide) applied to the skin can be used to prevent tick partment should be contacted for advice on report- bites. Use DEET with caution on children. In addi- ing and disposing of the carcasses. Hunters and trap- tion, permethrins can be applied to clothing, but pers should wear gloves when handling and cleaning should not be applied directly to skin. Persons at risk animals, and meat should be cooked thoroughly (see should be advised to wear long trousers, long-sleeved section on Game Meat). shirts and socks, as well as light-colored clothes to help detect ticks more easily. Eliminating gaps in Tick-Borne Diseases clothing, such as tucking pant legs into socks, can also be helpful. After being outdoors, all parts of the There are an increasing number of tick-borne dis- body should be carefully checked, especially haired eases that appear to be increasing in prevalence in areas. Outdoor clothes should be thoroughly washed certain regions of North America. These diseases and dried to kill any ticks. Ticks should be removed occur most commonly from May to September when from the body immediately with fine-tipped twee- ticks are most active. Lyme disease is caused by the zers. The tick should be grasped as close to the skin spirochete bacterium Borrelia burgdorferi, and is as possible and pulled upward with steady, even pres- found most commonly in the Northeast from Mas- sure. The tick should not be jerked or twisted to sachusetts to Maryland as well as the upper Midwest. prevent the mouthparts remaining in the skin. Ticks Human ehrlichiosis is a recently recognized tick- should not be handled with bare hands, and care borne disease caused by at least two types of bacteria should be taken not to puncture the body. After that infect leukocytes. The distribution of human removing the tick, the areas should be disinfected, infections correlates with the distribution of the tick and some people may wish to freeze the tick for later vectors, and human cases have been reported in the identification should illness occur within 2 to 3 Southeast, Northeast, upper Midwest, and West weeks. Community-based methods such as the appli- Coast (Fig 3). EhrlichiaFor chaffeensis, the causative cation of acaricides and landscape manipulation can agent of human monocytotropic ehrlichiosis, white- be applied if the risk warrants these more intensive tailed deer (Odocoileus virginianus) is the primary and expensive measures. Deer movement and pop- reservoir, and the geographic distribution of natu- ulation control can also be an important strategy. Wildlife Zoonoses 31

Table 1. Early symptoms of tick-borne diseases found in North America Non-specific signs (Fatigue, chills, fever, Disease headache, myalgia, swollen lymph nodes) Rash Lyme disease Yes Yes: Circular rash called erythema migrans with a bullseye appearance that expands to 30 cm diameter (70-80% of patients) Ehrlichiosis Yes: Including nausea, vomiting, Rare diarrhea, cough, joint pains, and mental confusion RMSF Yes: Including nausea, vomiting, and Yes: Macules on wrists, forearms, and ankles anorexia Babesiosis Yes: Including sweating, None hepatosplenomegaly, and hemolytic anemia

This is initiated at a local level in consultation with through the consumption of wild fish and game, and the state wildlife agency. However, activities that can fish consumption advisories are often 10,11issued. artificially increase deer populations, such as feed- People should be advised to contact the state health ing, should be discontinued. There are some new department regarding current fish consumption ad- tools available such as bait boxes that will treat wild visories. In general, for fish it is advisable to eat rodents with an acaricide; these are available from smaller, younger fish (within legal limits), because licensed control companies, and research is they are less likely to contain harmful levels of con- continuing to investigate other tick control measures taminants. The skin, fat, and internal organs should such as treatment of deer with acaricides and bio- be removed before cooking, and fish should be logic control measures. cooked in a manner that allows the fat to drain, for Finally, it is important to be able to recognize the example, by baking, broiling, or grilling. early symptoms of these diseases, so that medical Hunters should avoid killing and consuming wild attention can be sought promptly. Table 1 animalssumma- that are obviously sick. Wild game such as rizes the symptoms of the tick-borne diseases men- deer and waterfowl should be promptly eviscerated, tioned above. taking care to avoid contamination of the meat with the gastrointestinal contents. The carcass should Game Meat then be chilled before further preparation. Ab- scesses and other localized lesions can be carefully Fishing, hunting, and trapping of game animals for trimmed away; however, hunters should contact the food is a popular outdoor activity. Concern over local state wildlife agency if more generalized patho- food safety is no reason not to enjoy wild game meat, logic lesions are encountered, or if the meat appears because it provides healthy and wholesome food. of poor quality. Bovine has been con- However, wild game meat has the potential to cause firmed in a Michigan hunter (http://www.michigan. food-borne illnesses, and therefore the practices for gov/mdch) and illustrates the importance of appro- safe food preparation recommended by the United priate hygienic measures, in particular, wearing States Government should be followed (http://www.gloves during carcass preparation. foodsafety.gov/). For example, wild game meat Chronicis wasting disease is a progressive, fatal, one of the most common sources of neurologichuman disease of deer and elk. It is caused by Trichinella spp. infection.7 In addition, an outbreakinfectious proteins called prions, and is classified in of Escherichia coliO157: H7 was traced to jerky themade same group of diseases as scrapie of sheep and from deer meat.8 Furthermore, there is concern thatgoats, bovine spongiform encephalopathy, and handling and consumption of wild game mayCreutzfeldt-Jakob result disease of humans. Ongoing sur- in human exposure to novel microorganismsveillance and and at least two detailed epidemiologic the emergence of new diseases.9 Finally, there is investigations12,13 have found that there is currently concern about exposure to a variety of contaminants no evidence that chronic wasting disease has in- 32 Sleeman fected humans, and this is the position of the World ics of West Nile virus disease. Emerg Infect Dis Health Organization and the (CDC). However, the 11:1167-1173, 2005 following advice is given to hunters to avoid possible 6. Yabsley MJ, Wimberly MC, Stallknecht DE, et al: Spa- tial analysis of the distribution of , exposure: causative agent of human monocytotrophic ehrli- chiosis, across a multi-state region. Am J Trop Med 1. Do not shoot, handle, or consume any animal Hyg 72:840-850, 2005 that is abnormal or appears to be sick. If you see 7. Roy SL, Lopez AS, Schantz PM: Trichinellosis surveil- a sick deer, please contact the local state wildlife lance-United States, 1997-2001. MMWR Surveill Summ 52:1-8, 2003 agency immediately. 8. Keene WE, Sazie E, Kok J, et al: An outbreak of 2. Wear latex or rubber gloves when field dressing O157:H7 infections traced to jerky made from deer meat. JAMA 277:1229-1231, 1997 the deer carcass. 9. Ahl AS, Nganwa D, Wilson S: Public health consider- 3. Bone out meat from the animal. Do not saw ations in human consumption of wild game. Ann N Y Acad Sci 969:48-50, 2002 through bone and avoid cutting through the 10. Heaton-Jones TG, Homer BL, Heaton-Jones DL, et brain or spinal cord (backbone). al: Mercury distribution in American alligators (Alli- gator mississippiensis) in Florida. J Zoo Wildl Med 4. Minimize the handling of brain and spinal tis- 28:62-70, 1997 sues/fluids. 11. Burger J: Daily consumption of wild fish and game: exposures of high end recreationists. Int J Environ 5. Wash hands and instruments thoroughly after Health Res 12:343-354, 2002 field dressing is completed. 12. Belay ED, Gambetti P, Schonberger LB, et al: Creutzfeldt-Jakob disease in unusually young patients 6. Avoid consuming brain, spinal cord, eyes, who consumed venison. Arch Neurol 58:1673-1678, spleen, tonsils, and lymph nodes of deer. Nor- 2001 mal field dressing coupled with boning out a 13. Centers for Disease Control and Prevention: Fatal carcass will remove most, if not all, of these body degenerative neurologic illnesses in mean who par- parts. ticipated in wild game feasts-Wisconsin 2002: MMWR 52:125-127, 2003 7. If the deer is commercially processed, request that the animal be processed individually, with- Suggested Readings out meat from other animals being added. 1. Calle PP: Rabies, in Fowler ME, Miller RE (eds): Zoo These bullets are adapted from the Chronic Wast- and Wild Animal Medicine (ed 5). Philadelphia, PA, ing Disease Alliance web site (http://www.cwd-Saunders, 2003, pp-732-736 info.org). 2. Chin J (ed): Control of Communicable Diseases Man- Finally, the meat should be stored carefully, pro- ual (ed 17). Washington, DC, American Public Health tected from vermin, and cooked thoroughly. More Association, 2000 3. Davidson WR, Nettles VF (eds): Field Manual of Wild- details on carcass preparation can be found on the life Diseases in the Southeastern United States (ed 2). Pennsylvania Game Commission web site (http://Athens, GA, Southeastern Cooperative Wildlife Dis- www.pgc.state.pa.us). ease Study, 1997 4. Friend M, Franson JC (eds): Field Manual of Wildlife Diseases General Field Procedures and Diseases of References Birds. Madison, WI USGS Biological Resources Divi- sion, 1999 1. Bengis RG, Leighton FA, Fischer JR, et al: The role of 5. Samuel WM, Pybus, MJ, Kocan AA (eds). Parasitic wildlife in emerging and re-emerging zoonoses. Rev Diseases of Wild Mammals (ed 2). Ames, IA, Iowa Sci Tech 23:497-511, 2004 State Press, 2001 2. Kruse H, Kirkemo A-M, Handeland K: Wildlife as a 6. Williams ES, Barker IK (eds). Infectious Diseases of source of zoonotic infections. Emerg Infect Dis 10: Wild Mammals (ed 3). Ames, IA, Iowa State Press, 2067-2072, 2004 2001 3. Srinivasan A, Burton EC, Kuehnert MJ, et al: Trans- mission of rabies virus from an organ donor to four transplant recipients. N Engl J Med 352:1103-1111, Useful Web Sites 2005 4. Rupprecht CE, Blass L, Smith K, et al: Human infec- www.cdc.gov tion due to recombinant vaccinia rabies glycoprotein www.aphis.usda.gov virus. N Engl J Med 345:582-586, 2001 www.vdh.virginia.gov 5. Hayes EB: Epidemiology and transmission dynam- www.nasphv.org