Pediatric Annals

CME Article 

Febrile Illnesses Acquired from Animals

Sara L. Arguello, MD, MPH; Russell W. Steele, MD

Abstract

When any child is evaluated for fever without an obvious etiology, one question to ask is whether this patient has pets or has been exposed to animals, particularly sick ones. The obvious implication is that animals carry many unique, communicable pathogens that might account for the current illness. The likelihood is great because there are more than 77.5 million dogs and 93.6 million cats living in US households. They are just two of a number of species of animals that cohabit with our patients.

Abstract

When any child is evaluated for fever without an obvious etiology, one question to ask is whether this patient has pets or has been exposed to animals, particularly sick ones. The obvious implication is that animals carry many unique, communicable pathogens that might account for the current illness. The likelihood is great because there are more than 77.5 million dogs and 93.6 million cats living in US households. They are just two of a number of species of animals that cohabit with our patients.

Sara L. Arguello, MD, MPH; and Russell W. Steele, MD, are with the Division of Pediatric Infectious Diseases, Department of Pediatrics, Ochsner Children’s Health Center and Tulane University School of Medicine, New Orleans, LA.

Dr. Arguello and Dr. Steele have disclosed no relevant financial relationships.

Address correspondence to: Russell W. Steele, MD, Ochsner Children’s Health Center, 1315 Jefferson Highway, New Orleans, LA 70121; fax: 504-842-5647; or e-mail: RWSteele@aol.com.

When any child is evaluated for fever without an obvious etiology, one question to ask is whether this patient has pets or has been exposed to animals, particularly sick ones. The obvious implication is that animals carry many unique, communicable pathogens that might account for the current illness. The likelihood is great because there are more than 77.5 million dogs and 93.6 million cats living in US households. They are just two of a number of species of animals that cohabit with our patients.

These vast numbers greatly increase the likelihood that the animal is the source of a febrile illness. Wild animals also harbor organisms that are in their stool, urine, or secretions, indirectly exposing unsuspecting humans who enter the animal’s environment. In addition, exposure to dead animals can result in disease acquisition.

When a physician has identified that the cause of the fever is exposure to an animal, the parent should be advised as to practices to prevent further transmission, such as handwashing. If the cause of the fever is identified as something other than animal contact, the parent should still be advised as to risk prevention measures.

Many publications have discussed zoonoses by first identifying the animal and then elaborating on each disease that it can transmit to humans.1–6 This review is unique in that it begins with fever and the organ system involved and then suggests likely pathogens once animal contact is disclosed. The Tables are extensive, and every effort was made to make them complete; however, space limitations do not allow text discussion of all febrile zoonotic diseases for each organ system.

Skin and Skin Structure

Dogs and Cats

Bite injuries (see Table 1) constitute the greatest risk of contact with animals. Dogs are responsible for 80% to 90% of bites, and cats are responsible for 5% to 10% of bites. Approximately 30% of cat and 6% of dog bites result in cellulitis.1,7 Cat bites more commonly cause skin and skin structure infection because they produce puncture wounds that bury organisms deep in tissue, while dog bites cause tearing injuries that can be opened and irrigated, reducing the likelihood of cellulitis.

Skin and Skin Structure Infection After Animal Bites or Direct Contact with Animals

Table 1. Skin and Skin Structure Infection After Animal Bites or Direct Contact with Animals

The most common pathogen recovered from these infections is Pasteurella multocida, which is part of the oral flora of 70% to 90% of cats and 25% to 50% of dogs. Quite characteristic is that once exposed, the patient develops cellulitis in less than 24 hours with swelling, erythema, tenderness, regional lymphadenopathy, and a serous or sanguinopurulent discharge from the site. Fever occurs in 20% of infections, and is often accompanied by chills. Occasional local complications are septic arthritis, osteomyelitis, and tenosynovitis.

Other pathogens causing cellulitis and abscesses after dog and cat injuries are Capnocytophaga canimorsus,8Staphylococcus intermedius, and microaerophilic Streptococci. These organisms cause fever in more than 5% of cases.

Rats

Rat-bite fever is transmitted by bites, scratches, or exposure to oral, nasal, or conjunctival secretions, or urine from infected rodents and rodent-eating animals. Caused by either Streptobacillus moniliformis or Spirillum minus, this disease is increasingly reported because rats are now popular as pets among adolescents and preadolescents, possibly as a result of the Harry Potter book and movie series. (Children in these stories frequently have pet rats.) After an incubation period of 3 to 10 days, key symptoms of this illness are high fever, rash, and arthritis.9

Rat-bite fever begins with abrupt onset of fever, chills, myalgia, vomiting, headache, and occasionally adenopathy. The rash appears 1 to 3 days after the onset of fever and is most commonly maculopapular, although it can be petechial or pustular, and occurs predominantly on the extremities, including the palms and soles. Nonsuppurative and migratory polyarthritis or polyarthralgia follow the rash in 50% of cases.

If left untreated, it relapses in about 3 weeks. Complications include soft tissue and solid organ abscesses, pneumonia, endocarditis, myocarditis, parotitis, tenosynovitis, brain abscesses, and meningitis. The disease is severe and can be fatal in those younger than 3 months of age.

Farm Animals

Cutaneous anthrax caused by Bacillus anthracis most commonly affects the skin but is also known to cause disease of the oropharynx, mediastinum, and intestinal tract.10 Infection is acquired though contact with herbivores (eg, goats, cattle, sheep, horses, and pigs), or with their carcasses, through abraded skin.

Cutaneous anthrax has an incubation of 1 week or less and begins as a pruritic papule or vesicle that enlarges and ulcerates in 1 to 2 days. In 2 to 6 days, a subsequent black eschar forms. This process is characteristically painless but may develop with surrounding edema, hyperemia, and regional adenopathy. Other common signs and symptoms are malaise and headache. Fever occurs in 10% of anthrax infections limited to the skin and soft tissue but in virtually all cases with dissemination.

Fish and Wild Game

Erysipeloid caused by either Erysipelothrix rhusiopathiae or E. insidiosa is attained though contamination of skin abrasions while handling infected materials from fish and wild game or occasionally from a bite.11

Signs and symptoms vary from a localized cutaneous eruption to a more severe generalized cutaneous form and/or septicemia. Development of septicemia is often associated with endocarditis. Incubation is 1 to 4 days, and lesions slowly progress to be purplish-red painful indurations. Fever, lymphadenitis, and other constitutional symptoms appear in less than 10% of infections limited to skin and skin structure. If left untreated, Erysipelothrix infection is a self-limiting illness that lasts an average of 3 weeks.

Sheep and Goats

Skin lesions in humans after direct contact with sheep, goats, and wild ungulates, and particularly with their young, is termed ecthyma contagiosum, or contagious ecthyma caused by the Orf virus. The virus can persist in the soil or on animal skins and hair for months. Incubation is 3 to 6 days, and illness presents with a low-grade fever that subsides within 3 to 4 days in 70% of cases. Lesions form 1 week after exposure and can last for up to 3 to 6 weeks.

The lesions are usually located on the hands, arms, or face at the point of contact. They appear as red to violaceous vesicles, nodules, or maculopapules, progressing to weeping nodules with central umbilication. Other signs and symptoms are regional adenitis and a truncal maculopapular rash. Erythema multiforme and erythema multiforme bullosum are rare manifestations of Orf, as are disseminated disease and serious ocular damage.

Snakes

Reptiles’ mouths are actually quite clean, containing only non-virulent anaerobes, despite their common gastrointestinal colonization with Salmonella. Bites rarely result in cellulitis but do produce tissue trauma. If fever is present, other potential causes should be investigated.

Alligators

Bites from these large animals are severe, and infection almost always produces fever. Their mouth flora is quite unusual, with the most common organisms recovered from human infection after bites being Aeromonas hydrophila, Proteus vulgaris, and Pseudomonas.12

Pneumonia

Sheep and Animal Placentas

Q fever (Coxiella burnetii) presents as an acute febrile illness with lower respiratory tract symptoms, such as cough with chest pain, accompanied by fever in more than 90% of cases, sudden chills, retrobulbar headache, weakness, anorexia, malaise, and sweating (see Table 2, page 33). Bronchopneumonia is seen on chest X-rays, and abnormal liver function tests are common. With proper treatment, the pneumonia lasts 1 to 4 weeks then slowly resolves.

Pneumonia After Contact with Animals

Table 2. Pneumonia After Contact with Animals

It is usually acquired through airborne transmission or direct contact with animals or their products, particularly animal placentas. A famous report of multiple individuals acquiring disease while playing poker as a cat delivered her kittens under their card table led to the naming of this disease “poker players’ pneumonia.”13 The frequent infection of sheep in Spain has resulted in Q fever being the most common documented cause of pneumonia in young adult males in that country.

Sheep

Inhalation anthrax is referred to as woolsorter’s disease (also used to describe cutaneous infection) because it is most associated with sheep or their infected wool.10 A characteristic sign is the widening of the mediastinum on chest X-ray, a result of pulmonary inflammation and edema secondary to the organism’s toxin production. It has a long incubation period of up to 42 days with a prodrome of fever, sweats, non-productive cough, chest pain, headache, myalgia, malaise, nausea and vomiting.

Parrots and Parakeets

Psittacosis caused by Chlamydophila psittaci is an acute lower respiratory tract infection with fever in 80%, nonproductive cough, rash, chills, myalgia, headache, and malaise acquired by inhalation of infected bird excretions or contaminated dust. It is characterized by extensive interstitial pneumonia with radiographic changes that appear more severe than the physical findings would suggest. Incubation is 5 to 14 days but can be longer.

Pigeons

Cryptococcus neoformans pneumonia is attained through inhalation of soil contaminated with pigeon or other bird feces. It is often asymptomatic but in 80% of cases, symptoms present with fever along with cough, chest pain, and malaise. Occasionally producing a single solitary “coin” lesion on chest X-ray, Cryptococcus most frequently manifests as a diffuse infiltrate.

Farm Animals

Melioidosis (Whitmore disease) and glanders, caused by Burkholderia pseudomallei and B. mallei, respectively, are saphrophytic organisms that live in soil and water but are frequently carried to their human contacts by various animals such as sheep, goats, horses, swine, monkeys, and rodents. P. pseudomallei cause fever and severe respiratory symptoms with lung consolidation, abscesses, or necrotizing pneumonia.

The illness may look like typhoid fever or tuberculosis with pulmonary cavitations, empyema, chronic abscesses, and osteomyelitis. The closely related organism, B. mallei, causes a highly communicable disease of horses, mules, and donkeys. Clinical glanders is no longer endemic in the Western Hemisphere, but there are rare, sporadic cases reported in patients who have had contact with animals.

Meningitis

Hamsters and Guinea Pigs

Lymphocytic choriomeningitis (see Table 3, page 34) is a rodent-transmitted virus that is excreted in their urine, saliva, blood, and feces. It is acquired by humans through oral or respiratory routes, contact with animal fluids, or through skin abrasions. The illness has a varied biphasic presentation.14

Meningitis and Neurologic Diseases After Contact with Animals

Table 3. Meningitis and Neurologic Diseases After Contact with Animals

Incubation period is 8 to 13 days, and symptoms include a flu-like illness with retro-orbital headache, photophobia, anorexia, nausea, leukopenia, and thrombocytopenia. The fever usually lasts 1 to 3 weeks. The initial course has a good prognosis. The second phase 15 to 21 days after an asymptomatic period occurs in up to half of patients. It presents with meningitis or meningoencephalomyelitis.

Other occasional signs and symptoms of this phase are orchitis, parotitis, arthritis, leukopenia, myocarditis, and rash. With CNS involvement, a CSF lymphocytic pleocytosis occurs with mild hypoglycorrhachia. Transplacental infections can occur, resulting in congenital infection similar to that of congenital toxoplasmosis.

Monkeys

B virus (Herpes simiae or cerocopithecine Herpesvirus 1) causes an ascending CNS infection, termed monkey B encephalitis, in those who have close contact with an infected Eastern Hemisphere monkey.

This rare but highly fatal disease is acquired through exposure of skin or mucous membranes to an infected monkey’s saliva. Incubation is 3 days to 3 weeks, and the illness starts as an acute febrile illness with headache, often local vesicular lesions, lymphocytic pleocytosis, and variable neurologic patterns. There is itching, pain, and/or numbness at the exposure site.

Dogs

C. canimorsus is part of the oral bacterial normal flora of dogs and rarely cats and other mammals. Infection in humans occurs after a bite or scratch, and disease can be severe in individuals who are asplenic, chronic alcoholics, or who have chronic lung disease.8

More than half of these infected patients develop sepsis, a combination of septicemia and meningitis, or a fever of unknown origin. Incubation is 1 to 2 weeks. Signs and symptoms include fever, diarrhea, abdominal pain, vomiting, headache, confusion, disseminated intravascular coagulation, septicemia, meningitis, endocarditis, and, rarely, ocular infections.

Horses

Hendra virus, discovered in Australia in 1994, is acquired through direct oral or nasal contact with infected horses or their contaminated tissues.15 Incubation period is 4 to 18 days but can occasionally be several months.

The full spectrum and course of the illness is unknown, but it has been reported as being prolonged and initially starting as mild meningoencephalitis. Signs and symptoms range from mild acute fever, headaches, sore throat, dizziness, drowsiness, and disorientation to coma and death. Case fatality rate for clinical cases is 50%, and reactivation has been described.

Pigs

Nipah virus, discovered in Malaysia in 1999, is acquired from swine and may cause encephalitis. Infection is through direct contact with infected animals or their contaminated tissues through oral and nasal routes.16 Incubation period ranges from 4 to 18 days but can occasionally take several months. The full spectrum and course of the illness is still unknown. Signs and symptoms vary from mild with acute fever, headaches, sore throat, dizziness, and drowsiness to severe with altered mental status, coma and death. Case fatality rate for clinical cases is 50%.

Bats, Wild Animals, and Dogs

Rabies is a viral encephalomyelitis with a gradual onset and is almost always lethal. Illness is preceded by fever, a sense of apprehension, headache, malaise, and sensory changes at the site of exposure. It progresses to paresis or paralysis, hydrophobia, delirium, and seizures.

Incubation period is highly variable (days to years) but averages 3 to 8 weeks. Duration of illness is typically 2 to 6 days, and death occurs from respiratory paralysis. It is transmitted through bites, or contact with the saliva, urine, or neural tissue of infected animals. Diagnosis is made by fluorescent antigen testing in brain tissue of the offending animal or with fluorescent microscopy of a skin biopsy from the nape of the neck of the patient. Other methods of diagnosis include viral isolation from saliva, antibody in the CSF or serum of nonimmunized persons, and by PCR.

Cats

Infection with Toxoplasma gondii (toxoplasmosis) in the immunocompetent host causes a benign, self-limited infection with the only common manifestation being cervical lymphadenopathy. In some patients, a mononucleosis-like illness may occur with fever, malaise, sore throat, myalgia, and lymphocytosis persisting for days to weeks. Twenty percent have fever.

Cysts remain after recovery (especially in the brain) and may reactivate causing CNS disease if the patient becomes immunosuppressed. Likewise, primary infection in immunodeficient patients may disseminate to the CNS with signs and symptoms similar to a CNS tumor. Primary infection in the pregnant woman may result in a congenital infection with hydrocephalus, calcifications of the brain, and chorioretinitis.

Cats are the only definitive host of T. gondii transmitting disease by the fecal-oral route (litter boxes) or in dust containing infected fecal or urine matter. Ingestion of undercooked meat is also a source. Incubation period is approximately 7 days, and the infective oocyte can live in soil for more than 1 year.

Additionally, P. multocida has been reported as the pathogen causing meningitis in children bitten by or exposed to cats.

Raccoons

Baylisascaris procyonis, the raccoon roundworm, causes acute eosinophilic meningoencephalitis when transmitted to humans. Signs and symptoms include fever, mental status changes, and seizures. The presence of peripheral and/or CSF eosinophilia is the unique laboratory finding.

Although subclinical or asymptomatic infection may be relatively common, in patients with neurologic changes, severe neurologic sequelae or death are the usual outcomes.

Snails

Eosinophilic meningitis caused by the rat lungworm, Angiostrongylus cantonensis, occurs after ingestion of parasitized snails and slugs. Although most cases have occurred in Hawaii, there have been reports from many other states.

According to the Centers for Disease Control and Prevention, some infected people don’t have any symptoms, or have only mild symptoms that don’t last very long. Sometimes the infection causes eosinophilic meningitis. The symptoms can include headache, stiff neck, tingling or painful feelings in the skin, low-grade fever, nausea, and vomiting.

Gastroenteritis

Reptiles, Amphibians, and Almost All Other Animals

Virtually all animals are periodically colonized with one of the more than 2,500 species of Salmonella (see Table 4, page 35).17,18 Once transmitted to humans, the disease presents as an acute gastroenteritis with high fever; headache; nausea; vomiting; dehydration; diarrhea; abdominal cramping; bacteremia; and/or focal infection.

Gastroenteritis After Contact with Animals

Table 4. Gastroenteritis After Contact with Animals

It can occasionally present asymptomatically or as a protracted illness with gradual onset of fever, constitutional symptoms, abdominal pain, hepatomegaly, splenomegaly, and changes in mental status. Exposure is most commonly oral-fecal or by direct contact with turtles, chickens, reptiles, dogs, cats, birds, hamsters, rodents, and livestock. Incubation is 12 to 36 hours. Complications include osteomyelitis, abscesses, pneumonia, pyoderma, pyelonephritis, septic arthritis, cholecystis, endocarditis, meningitis, and pericarditis.

Cats and Farm Animals

Campylobacter is acquired through fecal-oral routes most commonly from cats, swine, sheep, and cattle, particularly the younger animals. Symptoms include diarrhea, abdominal pain, malaise, nausea, vomiting, and fever. Most stool samples contain visible or occult blood. Infection can also mimic appendicitis, intussusception, or acute inflammatory bowel disease.

In neonates, bloody diarrhea without fever can be the only sign of infection. Incubation is 2 to 5 days but can be longer, and symptoms typically last about 1 week. Complications of infection include Guillain-Barré syndrome, reactive arthritis, Reiter’s syndrome, erythema nodosum, a typhoid-like illness, febrile convulsions, septicemia, and meningitis.

Snakes

Cryptosporidium parvum illness is a consequence of fecal-oral spread,19 a potential culprit at petting zoos. Infections are also associated with cattle, rodents, cats, dogs, fish, sheep, birds, and reptiles. It causes non-bloody diarrhea with anorexia and vomiting. The vomiting is particularly common in young children. Symptoms wax and wane and include cramps, fatigue, and weight loss. The illness is self-limited, lasting 1 to 20 days. Incubation period is 2 to 14 days.

Dogs and Rats

Leptospirosis is an acute febrile illness with a varied presentation that is most frequently considered when patients are icteric and have laboratory evidence of hepatitis with direct (conjugated) hyperbilirubinemia and mild elevation of liver enzymes in serum. It can be acquired from a range of animals, mostly dogs, but also livestock, and contact with rat urine.

Anicteric disease is usually self-limited, presenting as relapsing fever or biphasic illness. Acute septicemia is characterized by conjunctival suffusion without purulent discharge and myalgia of the calf and lumbar regions. This phase includes fever in 80%, chills, headache, nausea, vomiting and transient rash all lasting 1 week. There may be an asymptomatic period lasting 3 to 4 days. The second phase is immune-mediated, consisting of fever; aseptic meningitis; conjunctival suffusion; uveitis; muscle tenderness; adenopathy; and a purpuric rash. This phase can last 1 week to several months.

Lymphadenitis

Rabbits and Squirrels

Cleaning rabbits, eating them undercooked, and squirrel bites, in addition to tick bites, are all epidemiologic mechanisms for developing tularemia, caused by Francisella tularensis (see Table 5, page 36).20

Lymphadenitis After Contact with Animals

Table 5. Lymphadenitis After Contact with Animals

Incubation period is 3 to 5 days. The abrupt onset of fever with adenitis, conjunctivitis with tender preauricular nodes (Parinaud’s oculoglandular syndrome) and adenitis proximal to the site of a squirrel bite are characteristic. Other clinical manifestations are chills, fatigue, myalgia, and headache.

Farm Animals

Brucellosis (caused by Brucella abortus, B. melitensis, B. suis, or B. canis) is acquired through contact with infected animals, their carcasses, or their secretions. The illness may be acute or insidious, presenting with acute, intermittent, or prolonged fever (fever of unknown origin) and adenopathy. Infection may also relapse.

Conclusion

For any child being evaluated for fever with an apparent organ system infection and with no clear etiology, clinicians should inquire as to whether the child has been exposed to animals. This may offer a clue to potential unique pathogens and alter the selection of antimicrobial agents and other clinical management. The parent should also be advised as to future appropriate risk-prevention measures, such as handwashing.

References

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  8. Brenner DJ, Hollos DG, Fanning GH, Weaver RE. Capnocytophaga canimorsus sp. nov. (formerly CDC group DF-2), a cause of septicemia following dog bite, and C. cynodegmi sp., a cause of localized wound infection following dog bite. J Clin Microbiol. 1989;27(2):231–235.
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Skin and Skin Structure Infection After Animal Bites or Direct Contact with Animals

AnimalOrganismCommon Clinical Manifestations
Cat/dogPasteurella multocidaCellulitis develops within 24 hours after a bite.Lymphadenopathy, fever, and chills are common.
Staphylococcus intermediusCellulitis seen in 1–3 days; infection localized.
Microaerophilic streptococciSuppuration and abscess formation after 2–5 days.
Group A StreptococcusErythema and edema often with streaks moving proximally (ascending lymphangitis).
Other organisms to consider:Capnocytophaga canimorsus, Corynebacterium, Moraxella, Streptobacillus moniliformis, and Spirillum minus.
RatStreptobacillus moniliformis and Spirillum minusRat bite fever is characterized by high fever, rash, and arthritis.
FishMycobacterium marinumSlowly progressive ulcer; fever in less than 10%.
Erysipelothrix rhusiopathiaeLocalized cellulitis; fever and necrotic skin rash in 10% of untreated cases.
Birds and wild gameE. rhusiopathiaeLocalized cellulitis; fever and necrotic skin rash in 10% of untreated cases.
SnakesInfection is unusual; fever can be caused by invenomation by poisonous snakes.
Farm animalsBacillus anthracisBlack eschar at site of exposure; fever suggests dissemination.
Sheep/goatOrf virusRed to violet maculopapules or vesiconodules, associated with a low grade fever.
AlligatorAeromonas hydrophilaExtensive cellulitis with high fever.

Pneumonia After Contact with Animals

AnimalOrganismCommon Clinical ManifestationsMethod of Diagnosis
Sheep/goatCoxiella burnetiiQ fever presents as a febrile pneumonia that can be severe. Chronic infection can cause endocarditis.Antibody titers, PCR, or staining. Inform lab if it is to be cultured.
BirdsChlamydophila psittaciFebrile interstitial or bronchopneumonia with a nonproductive cough.Antibody, complement fixation titers, or culture. Inform lab if it is to be cultured.
Cryptococcus neoformansPneumonia primarily in immune deficient hosts but also in pigeon breeders or those with extensive exposure to bird droppings.Cultures from tissues or body fluid, latex agglutination tests of serum or CSF, or India ink staining of the CSF.
RatsYersinia pestisPlague presents with lymphadnopathy, fever, shock, pneumonia, mediastinitis, and pleural effusion. Can spread person-to-person in respiratory droplets.Inform lab. FA test, PHA, ELISA, or culture.
RodentBurkholderia pseudomalleiMelioidosis or Whitmore disease: necrotizing pneumonia with abscess formation.Cultures and direct immunofluorescent microscopy.
Farm animalsBacillus anthracisWidening of the mediastinum with severe pulmonary edema.Quick ELISA anthrax-PA Kit, direct polychrome methylene blue smears, Gram’s stain, or culture.
HorseBurkholderia malleiGlanders; necrotizing pneumonia with abscess formation.Cultures and direct immunofluorescent microscopy.

Meningitis and Neurologic Diseases After Contact with Animals

AnimalOrganismCommon Clinical ManifestationsMethod of Diagnosis
Silver-haired bat, raccoon, skunk, fox, and farm animalsRabiesAcute viral encephalomyelitis with a gradual onset. Illness is preceded by apprehension, headache, fever, and sensory changes at bite site.Fluorescent antigen testing of the brain tissue of the offending animal. Fluorescent microscopy, viral isolation, antibody titers, or PCR of patient samples.
CatToxoplasma gondiiCervical lymphadenopathy, a mononucleosis-like illness, and lymphocytosis persisting for days to weeks.Serology
Bartonella henselaeCat scratch fever presents with malaise, lymphadenitis, and fever.IFA assay. PCR or immunodetection of biopsied lymph nodes
Hamster, guinea pig, rodentsLymphocytic choriomeningitisLCM’s biphasic presentation starts with a flu-like illness with a retro-orbital headache, leukopenia, and thrombocytopenia. The second phase can be meningitis or meningioencephalomyelitis.IgM capture ELISA or immunofluorescent assay. PCR of the CSF
HorseHendra virusThe full spectrum and course of the illness is still unknown. Reported to be a prolonged with mild meningoencephalitis, mild fever, sore throat, to coma and death.Serology and virus isolation
Eastern equine and Western equine encephalitisFulminant encephalitis, systemic febrile illness.Serology
PigNipah virusThe full spectrum and course of the illness is still unknown. Reported to be a prolonged with mild meningoencephalitis, mild fever, sore throat, to coma and death.Serology and viral isolation
MonkeysB virusAscending encephalomyelitis. Fever with headache, local vesicular lesions, lymphocytic CSF pleocytosis, variable neurologic patterns. Itching, pain, numbness at the exposure site.Test the offending animal for the virus
RaccoonBaylisascaris procyonisAsymptomatic, or it can cause severe encephalitis, meningoencephalitis, and endophthalmitis.Demonstration of the larvae on examination of tissue biopsies or by serology
Snails/slugsAngiostrongylus cantonensisCSF eosinophilic inflammation and hemorrhage; mild blood eosinophilia. An excruciating headache, neck stiffness, nausea and vomiting, and paresthesias.The diagnosis is generally based on history combined with an eosinophilic meningitis

Gastroenteritis After Contact with Animals

AnimalOrganismCommon Clinical Manifestations
Turtles, reptiles, amphibians, many animalsSalmonella sp.High fever, diarrhea, and vomiting. May produce focal infections, including osteomyelitis and meningitis/brain abscesses.
Cats, farm animalsCampylobacter jejuniFever, diarrhea, nausea, and vomiting. May produce Guillain-Barré syndrome.
Snakes, many animalsCryptosporidium parvumNonbloody diarrhea with anorexia and vomiting.
CattleEscherichia coli O157:H7Progressive bloody diarrhea causing hemolytic-uremic syndrome.
PigsYersinia enterocoliticaYoung children have fever, abdominal pain, and bloody diarrhea.

Lymphadenitis After Contact with Animals

AnimalOrganismCommon Clinical ManifestationsMethod of Diagnosis
Rabbit, squirrel, cat, many animalsFrancisella tularensisPainful adenitis with high fever. May also cause pneumonia or disseminate.Serology. It can be cultured, but the lab needs to be informed.
Goat, sheep, swine, dogsBrucella abortus, B. melitensis, B. suis, B. canisAll species: prolonged fever (fever of unknown origin; flu-like illness with lymphadenopathy, hepatosplenomegaly, and arthritis.Culture for a minimum of 4 weeks or serology.

CME Educational Objectives

  1. State the importance of obtaining a careful history regarding animal exposure when evaluating a patient with an illness of unknown etiology.

  2. Develop a systematic approach to evaluating a febrile illness in a patient with animal contact.

  3. Identify the clinical presentations of important animal-related infections.

Authors

Sara L. Arguello, MD, MPH; and Russell W. Steele, MD, are with the Division of Pediatric Infectious Diseases, Department of Pediatrics, Ochsner Children’s Health Center and Tulane University School of Medicine, New Orleans, LA.

Dr. Arguello and Dr. Steele have disclosed no relevant financial relationships.

Address correspondence to: Russell W. Steele, MD, Ochsner Children’s Health Center, 1315 Jefferson Highway, New Orleans, LA 70121; fax: 504-842-5647; or e-mail: .RWSteele@aol.com

10.3928/00904481-20101214-08

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