DISEASES TRANSMITTED ANIMALS TO HUMANSArkansas Academy of Family Physicians

June 21, 2014

Elton R. Cleveland D.V.M., M.D., FAAFPCAQ Sports Med, CAQ Adolescent Med

Objectives

• A) Identify several human diseases associated with animals.

• B) Understand some occupational risks associated with animal exposure.

• C) Discuss an occasional reverse zoonosis

Disclosure

• Financial relationships – none with companies or personnel that would have an impact on presentation

• Financial relationships – married – enough said

• Other disclosures – wife says I am old and crotchety –probably true

• I love animals.

Animals and Sport

Some People ?

Some People ?

• Source = San Francisco Newspaper

Pet Pearls

62% of U.S. households (72.9 million homes) have pets

• 78.2 million dogs• 86.4 million cats• 16.2 million birds• 13.0 million reptiles

Pet Pearls

• 164.6 million dogs and cats are domestic pets in USA

• Relationship between pets and childhood asthma is well documented

Pet Pearls • Iguanas, ranked in the TOP TEN pets, are the most popular reptile in the USA.

• Especially popular with teenage boys and young men.

Increasing Incidence of MRSA in the Community

• Rapid change over past decade

• Why?

Methicillin-Resistant Staphylococcus Aureus (MRSA)

American Society of Microbiology: 2007 Toronto

•MRSA found in 100% of fomites in subways, buses and trains

•MRSA survives up to two weeks on fomites

Methicillin-Resistant Staphylococcus Aureus (MRSA)

• Airline tray tables – WORSE!

• Public restrooms – only 6.3% positive

MRSA in Dogs and Cats

• Dogs and cats are the most common therapy animals used in healthcare settings.

• Healthcare settings that utilize animal-assisted therapy include long-term care facilities and pediatric institutions.

MRSA in Dogs and Cats (continued)

• With the emerging problem of community-acquired MRSA, we decided to re-visit local animal grooming clinics to determine if dogs and cats might be possible carriers of MRSA.

MRSA in Dogs and Cats (continued)

• All pets studied were from a local grooming clinic.

• They were deemed healthy and had not received antibiotics in the previous 30 days.

MRSA in Dogs and Cats (continued)

• Groomers, veterinarian, physician and student were all cultured.

• No personnel were found to harbor MRSA.

MRSA in Dogs and Cats (continued)

• All 42 animals were colonized with Staphylococcus aureus.

• Seven (16%) of the 42 isolates obtained were resistant to methicillin.

Animal Study Results

Recovered from outer surface of cages:

• Staphylococcus (coagulase + and -)• Bacillus• E. coli• Proteus spp.• Serratia marcescens• Other gram-negative microorganisms

Animal Study Results (continued)

Recovered from ALL water tanks in the animal cages:

• Pseudomonas aeruginosa

•Several animals were colonized with multiple organisms

Post-operative MRSA Infection

• Two-year old, hernia repair patient with post-op incision infection (MRSA)

• Dog at home cultured: MRSA-positive mouth

• Mother had multiple abscesses: MRSA-positive abscesses

• Specimens for child, dog and mother sent to Tulane!

Pearls of Pet Therapy Study• Animals are usually culture-negative for salmonella in home environments.

• Under travel stress (being placed into carriers, transported, or exposed to unfamiliar surroundings), they often become culture-positive for salmonella by the time they get to the hospital.

Recommendations

• If dogs and cats are used in animal-assisted therapy programs, they should be screened for pathogens, including MRSA

• Use of dogs and cats in institutional facilities should only be used after careful assessment of risk/benefits to all patients, staff members and visitors.

Animal Use Recommendations

• Handling of animals should only be allowed when potential risks and benefits are carefully considered.

• Handwashing should be strictly enforced after handling animals and / or cages.

Some people love their animals

Animal Bites

• Most common cause of Zoonosis.

• There are 2 – 4.7 million animal bites yearly.

• 1 out of 2 people in the U.S. (In life time)

• 1.5 % require an Emergency Department visit

• 2% require hospitalization

Animal Bites

• 80% of animal bites come from dogs.

• 85% of dog bites is from a family owned dog or a neighbor’s dog.

• Children are the most likely to get bitten. Boys ages 5 – 9 have the highest incidents of dog bites.

• Less than 300 deaths were attributed to dog bites between 1979 – 1996.

Animal Bites

• Little evidence for specific breed predilection but 75% of fatal attacks have been caused by Pit Bull & Rottweiler breeds.

• Male- dogs 3:1, Female- cats 3:1

Animal Bites

• Pasturella Multocida has been implicated as major pathogen.

• Infectious complications occur in approximately 20 – 50% of dog bites with a higher percentage occurring from cat bites.

Animal Bites

• Treatment medication options: Penicillin, Cefotaxime, Tetracycline, Bactrim, Ciprofloxacin and Levofloxacin.

• P. Multocida is resistant to Vancomycin, Erythromycin and Clindamycin.

Animal Bites

• Other organisms

• CDC – DF2 (“dysgonic fermenter Type 2”)• Capnocytophaga Canimorsus

• Fastidious Growth• 30% fatality rate with cases C. Septicaemia

Animal Bites

• CDC – NO1-(non – oxidizer) – similar to Acinetobacter• Proteus, Klebsiella, Enterobacter, Staph, Strep,

Bacteroides, Clostridium, Erysipelas, Etc.

• Rabies

Interesting Case

Rabies – Myth & Movies

MythWerewolves, Vampires & Rabies

Movies• Old Yeller

• Cujo

Rabies

• May be the oldest disease known to man ~ 2300 BC

• The word “rabies” has many origins.• Ancient Sanskrit: “rabhas” = to do violence• Greek: “lyssa” or “lytta” = frenzy or madness• Latin: “rabere” = to rave or rage

Rabies

• USA: 2 or 3 cases per year in humans

• Worldwide: >30,000 per year in humans.

Rabies• Before 1960 cases involved domestic animals.

• Currently, cases are now being seen in skunks, raccoons, and bats.

• Most human cases of Rabies are due to bat exposure.

• New Carrier: Woodchuck

Rabies

• Kansas

• Vaccine

• In 2006, a horse stabled at Tennessee Walking Horse National Celebration tested positive for rabies. • The CDC notified approximately 150,000 people who

attended the event of possible exposure to rabies.

US Rabies Reservoirs

Rabies - Speculation

• Carter Administration: Wanted to continue “coonhunting” while living in Washington, D.C.

• Raccoons transported to Virginia forests.

• 1977: By Carter’s inaugural address, the first case of rabies was reported in Virginia raccoons!

Rabies

• Treatment• Wound Cleaning• Rabies Immune Globulin (RIG)• Rabies Vaccine

• Controversy• USA/CDC = 5 doses vs. WHO = 3 to 4 doses.

Rabies

• RIG

• HDC 4 – 0, 3, 7, 14 or 28

Human Illnesses Associated with Animals

DISEASE (organism) ANIMAL SOURCE SOURCE

Aeromona sp. Aquatic Wound infection, contaminated food

Cat-Scratch

(Bartonella henselae)

Cats Scratches, bites, fleas

Brucellosis

(Brucella sp.)

Cattle, goats, sheep, swine, dogs (occas.)

Contact with birth products

Campylobacteriosis

(Campylobactes jejuni)

Poultry, dogs, cats, ferrets, hamsters

Contaminated food, direct contact, fecal-oral

Brucellosis

• Undulant fever

• B. Melitensis > B. Suis > B. Abortus> B. Canis

• Unpasteurized milk

• Contact Birth products

Brucellosis

• Sx intermittent fever• headache, chills, depression, profound weakness,

arthralgia myalgia, weight loss• Orchitis/Epididymitis in men • Spon. AB in pregnant women

Human Illnesses Associated with Animals (continued)

DISEASE (organism) ANIMAL SOURCE SOURCE

Leptospirosis(Leptospica sp.)

Dogs, rats, livestock

Contact with urine

Lyme Disease(Borrelia burgdorferi)

Wild rodents, birds

Tick bites

Salmonellosis(Salmonella sp.)

Poultry, reptiles, dogs, cats, turtles, etc.

Contaminated food, direct contact, person-to-person

Diseases Associated with Bioterrorism

DISEASE (organism) ANIMAL SOURCE SOURCE

Plague(Yersinia pestis)

Rodents, rabbits, cats, fleas

Contact with infected animals

Tularemia(Francisella tularensis)

Rodents, rabbits, cats

Tick bites, infected animals, claws / teeth of cats

Male Xenopsylla cheopsis (oriental rat flea) engorged with blood. This flea is the primary vector of plague in most large plague epidemics in Asia, Africa, and South America. Both male and female fleas can transmit the infection.

Photo Credit: courtesy of the Centers for Disease Control and Prevention

Diseases Associated with Bioterrorism (continued)

Anthrax• The name Anthrax comes from the Greek word “anthrakas” which means “coal”, reflecting the black rash associated with this infection.

• Encapsulated

• Resistant Spores• 200 year old remains discovered in an archeological dig• Resistant to microwave irradiation at 100◦C for 30

minutes• Resistant to conventional pasteurization

Anthrax in Humans

• Cutaneous Anthrax: black necrotic “eschar”

• Inhalational Anthrax: flu like symptoms, mediastinum wide, highly fatal.

• Gastrointestinal Anthrax: infection oral, → highly fatal.

Anthrax in Humans

Outbreaks• Russia – Sverdlovsk – April/May 1979

• Spores were released into the air surrounding a biological weapons facility.

• Humans and cattle were infected.

Other Diseases Associated with Animals

FUNGAL INFECTIONS SOURCE

Cryptococcosis Birds

Ringworm Cats, dogs, rabbits, rodents

Sporotrichosis Cats

Other Diseases Associated with Animals(continued)

PARASITES SOURCE

Dwarf Tapeworm Hamsters, rodents

Cryptosporidiosis Domestic animals

Cutaneous Larva Migrans Dogs, cats

Dog Tapeworm Dogs, cats

Giardiasis Dogs, cats, beavers

The pork tapeworm, Taenia solium has a scolex that features a double crown of 22 to 32 rostellar hooks and four simple, round suckers. As with other cestodes, the pork tapeworm fastens onto its host (primarily muscles for this species) and absorbs nutrients through its skin.

Other Diseases Associated with Animals(continued)

CHLAMYDIAL and RICKETTSIAL

SOURCE

Ehlichiosis Deer, dogs, horses

Psittacosis Psittacine, domestic birds

Q Fever Sheep, other livestock, research labs

Rocky Mountain Spotted Fever

Dogs, wild rodents

Ehrlichiosis

• Monocytotropic Ehrlichiosis in dogs = E. Canis

• Human Monocytotropic Ehrlichiosis in humans = E. Chaffeensis• Symptoms include: fever, malaise, chills, headache,

Arthralgia Myalgia, Anorexia, nausea, Leukopenia, Thrombocytopenia and increase in liver enzymes.

Anaplasmosis in Cattle

• Anaplasma marginale

• 19 different tick vectors

• Blood transfusion

• Severity of illness increases with animals age.• Calves more resistant• Older cows are more susceptible

Anaplasmosis

• First recognized in the mid 1990’s

• Reportable by the CDC in 1999

• Bacterium Anaplasma Phagocytophilum

• CDC previously described as HGE – Human Granulocytic Ehrlichiosis

Group A Streptococcus (GAS)

• It is debated whether or not dogs in an household can serve as a source of infection for humans.

• Human beings are the primary reservoir for GAS, not dogs, so when an animal in an household is infected, is this an example of a reverse osmosis?

• (Crowder et al., 1978: Wilson et al., 1995) found zero correlation between GAS in presence of dogs in a household and human infection.

Group A Streptococcus (GAS) (Continued)

• (Mayer & VanOre, 1983, Copperman, 1982) documented resolution of chronic GAS in households after isolation of organism from, and treatment of, dogs.

• There has only been one case reported of Zoonosis GAS involving cats. (Roos et al., 1988)

Other Diseases Associated with Animals(continued)

VIRAL INFECTIONS

SOURCE

West Nile Birds

Hantaviruses Wild rodents

Rabies Bats, cats, ferrets, dogs

The Culex mosquito, which bites from dusk to dawn, is a vector of St. Louis encephalitis and West Nile virus; it becomes infected by feeding on birds that carry these viruses. St. Louis encephalitis and West Nile virus affect mainly older adults.

Other Diseases Associated with Animals(continued)

Avian Influenza A (H5N1)

NEWS NEWS FLASHFLASH

Bird Flu Hits Trailer Park in FloridaDateline: Orlando