Zoonoses
Carol Glaser DVM, MD Pediatric Infectious Diseases University of California, San Francisco & Pediatric Infectious Disease Division Kaiser Permanente Oakland, CA
Outline
Overview of zoonotic diseases “Fact or Fiction” dealing with common misperceptions or questions Focus on zoonotic aspect of different disease (rather than Rx) Common and not-so-common illnesses, range of animal hosts/types of zoonoses Mostly practical information…but some esoteric…
1 Outline
Pet related zoonoses – Cats and dogs Ringworm, toxoplasmosis, Bartonella/CSD, GAS and MRSA – Less traditional pets Pocket pets-RBF Wildlife issues Rabies
What is a zoonosis?
Zoonosis refers to diseases that can be passed from animals, whether wild or domesticated, to humans
2 Tick • Borreliosis • Trypanosomiasis
Sheep Direct contact • Q fever Food chain Cattle Direct • Salmonella Deer contact • E. coli • Tularemia • Campylobacter • Cryptosporidum • Leptospirosis • Mycobacterium • Rat-bite fever • Brucellosis
Rat • Salmonella • Campylobacter Flea • Avian flu Chicken & Eggs • Plague • Haemorrhagic fever
• Rabies
Bat Pigeon / Pet Bird • Psittacosis • Cryptococcus • Toxocariasis • M. avium-intracellulare • Toxoplasmosis • West Nile virus • Rabies • Rabies Mosquito • JEV • Leptospirosis • Bartonella hensleae • Chik Dog • Dengue Cat
Companion Animals US households 2012
Dogs Cats Birds Horses
% households 37% 30% 3% 1.5%
Average/ 1.6 2.1 2.3 2.7 household
Total # 69,926,000 74,059,000 8,300,000 4,856,000
https://www.avma.org/KB/Resources/Statistics/Pages/Market-research-statistics- US-pet-ownership
3 Specialty and Exotic Animals 2012
“Pocket pets”; ownership increasing
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Lots of reptiles, mostly increasing since 2007 https://www.avma.org/KB/Resources/Statistics/Pages/Market-research-statistics-US-pet- ownership.aspx#exotic
Zoonoses: General
Many are missed because of vague clinical presentation –’viral’ On the other hand, people often worry unnecessarily and/or erroneously ascribe illness to pets Transmission complex and often ‘new twists’ For the unusual/orphan diseases, diagnosis problematic
4 A Partial List of Bacterial Zoonoses Anthrax Psittacosis Brucellosis Q Fever Campylobacteriosis Rat-bite Fever Cat Scratch Disease Relapsing Fever Rocky Mountain Spotted Ehrlichiosis Fever E. coli O157:57 Salmonellosis Glanders Tularemia Leptospirosis Typhus Listeriosis Yersiniosis Lyme Disease Zoonotic tuberculosis Melioidosis Plague
A Partial List of Viral Zoonoses
Arenaviruses (LCMV, Lassa, S. Herpesvirus B American hemorrhagic fevers) Influenza (avian) Bat lyssaviruses Japanese encephalitis Colorado tick fever Nipah Ebola Rabies Equine encephalitides (WEE, Rift Valley fever EEE, VEE) SARS Hantaviruses (Hantaan, Sin Vesicular stomatitis Nombre) West Nile Virus Hendra
5 A Partial List of Parasitic Zoonoses
Protozoa Helminths:
(roundworms, tapeworms, flukes)* Babesiosis Anisakiasis Cryptosporidiosis* Cysticercosis Leishmaniasis* Hydatidosis Giardiasis* Mesocestoidiasis Toxoplasmosis* Schistosome dermatitis Trypanosomiasis (Swimmer’s Itch) Trichinosis* Visceral Larval Migrans* Toxocariasis/Baylisascaris
Emerging Infectious Diseases
Estimated that 75% are zoonotic – Many viral—SARS, MERS – Many vectorborne (e.g., West Nile virus, Ebola, Zika )
-Chomel et al., Emerg Inf Dis 2006
6 Dermatophytosis
“Ringworm”
Pets are a common source of ringworm and are almost always symptomatic
Fact or Fiction?
7 Dermatophytosis (aka Ringworm)
Fungal pathogen Found world-wide, prefer hot and humid environments Infection of the hair, nails (oncyhomycosis) and/or superficial layers of the skin caused by several fungal species Classified by mode of transmission – Human-to-human (anthropophilic) – Soil (geophilic) – Animal-to-human (zoophilic) vs. “name” based on where on body
Name by body site (rather than fungal species)
Tinea corporis - body surfaces other than feet, groin, face, scalp, hair or beard hair – T rubrum, (T tonsurans, M canis, T interdigitael/T mentagrphytes, M gypseum, T violacerum and M audouini) – Tinea corporis from infected animals often intense; inflammatory Tinea pedis - foot, (athletes foot) – T rubrum, T interdigitale, and E floccosum (barefoot locker room) Tinea cruris - groin – T rubrum (E floccosum, T interdigitale, T mentagrophytes) – Spread from tinea pedis (risk factors obesity, diabetes, sweating, immunodeficiency) Tinea Capitis - scalp hair – Almost always small children – Trichophyton and Microsporum species are the major causes Tinea unguium - nails Tinea barbae - beard hair
8 Dermatophtosis (Ringworm)
One of the most common pet-associated and occupational zoonoses Estimated that 2 million people in the US are infected each year as result of animal contact Spores from infected animals can be shed into the environment and live for up to 2 years Incubation period = 1-3 weeks Brushes, bedding, furniture, or anything that has been in contact with an infected animal or the animal's hair can contain spores
Stehr-Green JK, Vet Clin N Am Small Anim Pract, 1987
Overview of “ringworm“
Mode transmission Clinical Fungal types Human-to-Human Mild to non-inflammatory, Trichophyton tonsuran (skin-to-skin or skin-to-hair) chronic T mentagrophytes interdigitale T violaceum T soudanese T schoenleinii Microsporum audouinii M ferrugineum Epedermophtyone floccosum
Soil-to-human Moderate inflammation M gypseum (indirect contact with infectious M fulvum arthrospores in environment or T ajelloi fomites) T terrestre Animal-to-Human Intense inflammation • Microsporum canis (skin-to-skin or skin-to-hair) (pustules and vesicles • Trichophyton possible) mentagrophytes
9 Disease in Animals
Dogs – Generally starts as alopecia – Erythema, scaling and pruritis may develop around lesions – Asymptomatic but still capable to shedding spores into environment – Microsporum canis (70%), M gypseum (20%) and Trichophyton mentagrophytes (10%)
Cats – Up to 90% asymptomatic – Most commonly there are manifestations in kittens or long- haired cats – Poor hair coat or circular lesions on face/paws – Most is Microsporum canis (90%)
More common in sheltered and/or young animals
Clinical - Humans
Anthropophilic Zoophilic human-to-human animal-to-human
Tends to be more inflammatory
Symptoms caused by hypersensitivity reaction of the host
10 Diagnosis & Treatment
Wood lamp primarily helpful for Microsporum infection (affected areas fluoresce yellow-green)
Humans - Rx dependent on fungal species and body site – Tinea capitas Terbinafine (Itraconazole or Fluconazole or griseofulvin) – Tinea corporis, cruris, pedis Topical antifungal, drying powder Optimal Rx controversial Griseofluvin for M canis
Pets – Eradicating disease may be challenge if multiple animals – Response to Rx monitored by dermatophyte culture as many animals will remain culture positive while improving clinically – Topical Rx and/or systemic Rx; topical miconazole/clotrimazole, oral ketoconazole
Summary Ringworm
Some ringworm comes from pets but probably only minority of cases Ringworm transmitted from pets is often more inflammatory > humans Pets can harbor ‘ringworm’ and most of the time they are asymptomatic Consider asking about pets if ringworm is refractory to Rx
11 Toxoplasmosis
Toxoplasmosis is generally acquired from cats and it is safest not to have cats when pregnant
Fact or Fiction?
12 Toxoplasma gondii
Obligate intracellular parasitic protozoan Capable of infecting all warm-blooded animals Cats definitive host (and other felines); only host where parasite undergoes sexual reproduction Worldwide distribution – Seroprevalence in US-born persons (12–49 y) (NHANES) 1988-1994: 14% 1999–2004: 9%
Toxoplasmosis Life Cycle
• Cats (and other felines definitive host) • Naïve cats ingest bradyzoites • Cats generally either asymptomatic or have self-limited illness • Other animals can become infected from oocysts • Tissue cysts in meat, unwashed produce or placental transmission
13 Humans and Toxoplasmosis
After infection – Humans often asymptomatic or – Flu-like illness – Like other animals, tissue cysts and long term humoral response Two important groups: – Pregnant women with primary infection – Immunocompromised – primary infection or reactivation
Toxoplasmosis Infection in Pregnancy
Asymptomatic (50-90%) Fatigue, lymphadenopathy Fever, H/A, pharyngitis, myalgia Rarely enanthem (rash on mm mouth), retinal disease
14 Congenital Toxoplasmosis Transmission can occur during all trimesters; least likely 1st trimester but most severe Classic triad – Hydrocephalus – Intracranial calcifications – Chorioretinitis But most cases not classic-more subtle with IUGR, microcephaly High index of suspicion for diagnosis
Congenital Toxoplasmosis Additional Signs/Symptoms
Fever Ocular abnormalities H-S-megaly Pneumonia Lymphadenopathy Seizures Jaundice Vomiting, diarrhea Rash Hypothermia Labs: Abnormal CSF, anemia, eosinophilia, and coagulopathy
15 Toxoplasmosis Infection in Pregnancy
Source of infection unknown in approx 50% Food: meat and fresh fruit, vegetables, raw eggs and rarely mussels, oysters, unpasteurized milk (and even water) Gardening Rarely: blood transfusion, laboratory-acquired
Cats - how commonly is it transmitted from cats?
Cats and Toxoplasma
Cats are generally asymptomatic or mildly ill during acute infection Shed oocysts for ~10 days but usually only during acute infection (i.e., only once/lifetime) <1% of cats shed oocysts on any given day Oocysts are quite resistant – oocysts survived outdoors in Texas (6°C–36°C) in native cat feces, uncovered, for 46 days, for 334 days when covered, and outdoors in soil buried at the depth of 3–9 cm in Kansas for 18 months – oocysts survived at −21°C for 28 days
16 Toxoplasma & Food animals United States
Will free range/organic meat increase %? Jones JL, Clin Infect Dis, 2012
Toxoplasmosis Summary
Although cats are the definitive host for Toxoplasmosis, pet owners rarely acquire the infection from their pet cat The best way to prevent Toxoplasmosis is to eat meat well cooked, wash fruits and vegetables and wear gloves for soil contact Pregnant women and Immunocompromised patients do not need to give up their cat (but should avoid cleaning litter box or wear gloves)
17 Group A Streptococcus
Pets are a relatively common source of Strep throat in pediatric patients
Fact or Fiction?
18 Group A Strep (GAS) (Strep pyogenes)
Humans are natural reservoir Pharyngitis, dermatitis, scarlet fever and rheumatic fever are main syndromes Sometimes perianal cellulitis, vaginitis, localized abscesses
GAS and Pets
Earlier studies found that dogs were persistent reservoirs for GAS
Lots of anecdotal reports of treatment of dogs and cats as a means of controlling on-going transmission in households
One study of the households of people with recurrent GAS pharyngitis found: – 42% dogs positive – 36% cats positive
-Cooperman SM, NY State J Med, 1982 -Kurek C, Epidem Reviews, 1971
19 Pets and recurrent Strep throat
However, these studies were flawed…
GAS and Pets
Group A vs. non Group A strep; early studies used crude antimicrobial data on bacitracin susceptibilities rather than genetic subtyping Later when Lancefield typing done – True prevalence in household pets only 0-3% and not correlated with the presence of infection in the owner
- Crowder HR, Int J Zoonoses, 1978
20 GAS and dogs/cats - more recent studies Longitudinal study – Households of children with acute pharyngitis Throat cultures from children with acute pharyngitis Concurrent samples from pets in household – 230 pets sampled—No group A strep found in pets Another study – Children with Group A Strep
Only 2 of 61 tested pets were positive
-Wilson KS, Ped ID J, 1995 -Falck G, Scand J Infect Dis 1997
Summary GAS and pets
No convincing evidence that dogs or cats are a source of GAS…but there may be rare instances If need to Rx pets- PCN/Amox (same as people) Infected pets typically show no signs or symptoms of illness or tonsillar enlargement and usually “lose” the infection 2-3 weeks
21 MRSA in animals is a “humanosis”
Fact or Fiction?
Trivia ? The first recognized fatal MRSA case in a dog belonged to an actress Fact or Fiction?
22 Staph aureus Multitude of lineages Generally associated with specific host groups – Humans – Cattle – Poultry – Feline Methicillin resistance often due to integration of Staph cassette chromosome-mec (scc mec)
Bella was the first dog ever publicly recorded to have died from the human form of MRSA – UK, 2004
23 MRSA in Animals
MRSA has “jumped from humans to household pets” Animals can carry the bacteria on their skin and may transmit it back to the pet owner or spread it to other animals
MSRA and Pets
Just like people…. Asymptomatic carrier Most common conditions – Skin infections and ear infections – Post-op incisional infections or wounds – Also: UTI, auditory canal, and joints
24 MRSA
MRSA LIKELY A “HUMANOSIS”
AKA “REVERSE ZOONOSIS” OR “ZOOANTHROPONOSIS”
25 Human Transmission to Dog
76 y/o male with DM, CLL, and COPD, pulm aspergillosis on steroids MRSA cellulitis in Nov 2007 Cellulitis again with same MRSA in Feb 2008, pos nasal MRSA Late Feb 2008 his – 8 y/o dog developed cellulitis (had had ruptured cruciate repair Dec 2007, failed implant and another surgery early Feb 2008) – MRSA from blood, tissue samples neck and fluid drainage from right leg/surgical site pos
-Rutland BE, Emerging Infect Dis, 2009
Owner à Dog
Dog became increasing lethargic, systemic inflammatory response (SIRS) and neck developed ulceration and necrosis followed by skin sloughing/generalized edema and septic shock Euthanized 48 hours after admission
Rutland BE, Emerging Infect Dis, 2009
26 Human to Dog
PFGE identical to owner’s MRSA
Conclusion: human to dog transmission
• Rutland BE, Emerging Infect Dis, 2009
MRSA transmission study pets and people
MRSA infections 1st isolated from infected animal (e.g., post-op wound, chronic rhinitis, UTI) àfollowed up with family and vet staff Examined vet hospital and (other) pets in home – MRSA isolated from 8 animals (5 dogs/3 cats) – 14/88 (16%) household contacts or vet personnel + MRSA (indistinguishable MRSA isolate recovered from at least one human/ each animal case) – Both animalà human AND humanà animal transmission suspected
Weese JS, Veterinary Microbiology, 2006
27 Transmission MRSA
– Both animalà human and humanà animal transmission likely occur
Weese JS, Veterinary Microbiology, 2006
Summary MRSA and pets
MRSA in pets behaves more like a ‘humanosis’ rather than a zoonosis Like people, only a small percentage of animals (or humans) that acquire MRSA develop illness Animals can become 'colonized' and potentially serve as a reservoir for future development of infection (especially if they undergo surgery)
28 To prevent Cat Scratch Disease (CSD), cats should be tested and treated every 3 years, especially cats belonging to immunocompromised people
Fact or Fiction?
Bartonellosis (CSD)
Cat scratch disease caused by Bartonella species (type of proteobacterium) Cats are main reservoir – B. henselae, B. clarridgeiae, B. koehlerae Other animals can also serve as reservoir Typically from a scratch (sometimes bite) Cat fleas (Ctenoceph felis) involved in transmission of B. henselae among cats Unclear role of fleas in human transmission
29 Bartonellosis background
Cats – B. henselae is a nearly perfectly adapted parasite—produces high-grade bacteremia without disease – 5-41% of cats positive blood culture – Intermediately positive
Bartonellosis: Clinical
Cat scratch disease (CSD); – Benign, self-limiting lymphadenopathy, low grade fever – Often lesion at inoculation site – Serious conditions however are in the differential; Lymphoma, carcinoma, MTB, neuroblastoma
30 Bartonellosis: Clinical
Atypical forms – Erythema nodosum – Perinauds oculoglandular syndrome – Hepatic granuloma – Osteomyelitis – Pulmonary disease – Optic neuritis – Encephalopathy Immunosuppressed – Bacillary angiomatosis – Peliosis hepatitis
Bartonellosis
Prognosis: generally excellent For normal hosts-once immune, always immune Treatment: – For most forms-no RX – Immunosuppressed or severe cases: azithromycin or doxycycline and rifampin
31 Bartonella testing in cats
Positive serology = Bartonella bacteremia Bartonella bacteremia can be intermittent Bacteremia can last months or even years in cats Testing in cats is recommended by some veterinarians ?Utility of testing? – Treatment of cat not efficacious – Positive results? Negative results?
CSD summary
Utility of testing cats is very questionable! If human illness occurs, not a reason to get rid of cat! Since fleas are considered ‘essential’ to maintenance of infection in cats good flea control; – “vigilant elimination of fleas from pets...” Also for prevention avoid unnecessary “trauma” cats à people
32 A child was bitten by squirrel in the park 2 days ago…animal can’t be found…patient should undergo rabies PEP
FACT or FICTION
A child picked up bat during camping trip and the bat later flew away, no bite wound - this child needs PEP
Fact or Fiction?
33 Rabies is treatable
Fact or Fiction
Rabies shots are painful and are
given in the abdomen Fact or Fiction
34 Background
• Causes a severe acute progressive encephalitis • One of the ‘oldest’ infectious disease known to man • The world’s “most deadly virus” • Latin for: to “be mad”/”madness”
Rabies The “quintessential” zoonosis
35 Etiology
• Family: Rhabdoviridae § Negative-stranded RNA genome • Genus: Lyssavirus • Envelope virus, bullet-shaped
Epidemiology
• Only 1-2 recognized cases/year in the United States…so why is it so important? § “Uniformly fatal” without vaccine (until recently) § Tremendous ‘angst’: ~40,000 persons receive post-exposure prophylaxis (PEP) in the US § Many encephalitis cases are ‘rule out’ rabies … on the other hand, cases are missed § World: 50,000-100,000 cases/year
36 • Most cases of rabies in India, China, SE Asia, Iran, Africa and South America • Most are canine rabies • Estimated 50,000 cases/year
Rabies Reservoirs
• All mammals are susceptible
• However some species much more important > others, e.g., canine rabies, raccoon rabies, bat rabies, skunk, etc.
• Humans generally “dead-end” hosts
37 About rodents
There have been no documented cases if rabies in humans associated with expiate to rabid rodents in the US
Caveat; if rodent extreme bizarre behavior, then consider testing and/or PEP
Bats (non-terrestrial) and Rabies
• Most common source of human infection in US • Since 1990, > 90% of endemically acquired rabies in the US • Exposure to bat not always recognized, especially bites
38 Bites from bats may be overlooked
-Jackson A, Lancet, 2001
Clinical
• Incubation period ranges from few days to >1 year § Most cases present between 2 and 16 weeks • Pleomorphic manifestations, often mistaken for other CNS diseases (e.g., case 2) • Initial symptoms are nonspecific: § Fever, malaise, fatigue, anxiety, headache § Half of patients have pain, itching or paresthesias at site of the bite § Lasts 2-10 days
39 Clinical
After prodrome: • Furious form (aka “mad dog”) § Increasing agitation, hyperactivity, seizures, hallucinations, aggressive behavior, hydrophobia (spasm of respiratory muscles when attempting to drink) § Coma develops, then death • Paralytic form (aka dumb rabies) § Progressive lethargy, incoordination and ascending paralysis § Respiratory muscle paralysis may occur § Coma, then death
Diagnosis of Rabies
• Always consider in case of acute onset, rapidly progressive encephalitis
• Diagnosis before death is ‘tricky’ but do-able
• Testing after death includes: § Testing for viral antigen by DFA in brain tissue
40 Prevention and Treatment Issues These issues often confused…note the differences
• Rabies pre-exposure prophylaxis § Given to ‘high risk’ individuals such as veterinarians, animal control workers, spleunkers before exposure § 3 doses vaccine • Rabies post-exposure prophylaxis (PEP) § Given following a bite from rabid (or suspected rabid) animal § Rabies Immune globulin (RIG) and 4 doses vaccine (day 0,3,7,14) § Highly effective for prevention § Vaccines not given in abdomen • Rabies “Treatment” § No known effective Rx; once symptoms develop, vaccine and RIG of no benefit § Experimental treatment
PEP - Yes or No?
• Type of exposure (bite, non-bite) § If bite: provoked vs. unprovoked § Assess other circumstances of exposure, e.g., behavior of animal • Severity of wound • Animal species involved • Animal health and vaccination history • Local animal rabies epidemiology • Animal available for observation / testing • Urgent but not “emergency”, consult local public health
41 “Treatment” Human Rabies Survivors - Prior Experiences in US
• Recovery without rabies PEP § 15 year old female, Wisconsin, 2004àMilwaukee protocol § 17 year old female, Texas, 2009 (“Abortive Case”) • Both met case definition for human rabies based on clinical manifestations and rabies virus specific antibodies in serum and CSF • Rabies virus, antigen, nucleic acid not detected from these patients • Antibody identified “early”
-Willoughby et al., New Eng J Med, 2005 -CDC, MMWR, 2010
however
Several other investigators have attempted the Milwaukee protocol for ‘treatment’ of rabies and failed
Aramruro A, Clin Infect Dis, Sept 2011
42 Rabies Summary
Rodents low risk for rabies and most bites don’t require PEP – always best to discuss with public health department Bat bites are often not noticeable and any child with bat contact (if unobserved) need to assume bite occurred and rabies PEP should be considered (test bat is possible) Rabies is preventable Whether rabies is ‘treatable’ is questionable
Rat bite fever is almost always associated with a bite from rat… FACT OR FICTION
43 Rat Bite Fever: Microbiology
Two distinct disease syndromes – Streptobacillus moniliformis: most cases in US Incidence unknown since not a reportable disease Probably rare but likely underdiagnosed Relatively difficult to isolate
– Spirillum minor: not generally found in US Mostly in Asia Different syndrome Sodoku or relapsing fever
About Rodents
Approximately 3% of US households have pet rodent (gerbil, hamster, mouse or rat) Mostly rats, however other rodents can transmit Doesn‘t have to be pet rat, can be acquired from wild rodent (including dead rodent) Cats that hunt rodents can harbor organism in their mouth (transiently)
44 Rat Bite Fever Streptobacillus moniliformis: Epidemiology
Often transmitted by bite or scratch of rats, mice, squirrels, carnivores that prey on rodents Can be acquired through handling of dead rats 50-100% wild and lab rodents harbor organism Food/water contaminated with infected rat excreta (cases called Haverhill)
40% of cases have no history of bite
29% of US households experience rodent problem
Rat Bite Fever: Clinical
Incubation: ~7 days (range 1-10 days) Abrupt onset fever (irregular relapsing fever) Chills, headache Migratory arthralgias, myalgias
Clinical features similar to other diseases Diagnosis usually requires high index of suspicion (blood culture/add +)
45 Rat Bite Fever
Complications – Endocarditis, myocarditis, pericarditis – Meningitis – Pneumonia – Abscesses in “virtually every organ” Treatment – Penicillin or Doxycycline – Untreated: 7-13% mortality
Elliot et al., Clin Microbiol Rev, 2007 Dijkmans et al., Infection, 1984 Pins et al., Clin Inf Dis, 1996
46 And more recently
San Diego, 2013 10 year old healthy male with 2 pet rats – Presented to PMD with complaints of fever, vomiting, rigors, HA and leg pain Temp 102.6°, normal exam, dx ‘viral gastroenteritis’ Following day confused and weak/collapsed Paramedics called, unsuccessful resuscitation Streptobacillus moniliformis recovered from lung, liver and epiglottis MMWR, Notes from the Field, 2014 19; 63 (50)
Summary RBF
Transmitted by rats and other rodents Also can be transmitted by cats In addition to bites, can be transmitted by scratches and contact with oral secretions of rodent and ingestion Diagnosis requires high index suspicion Very treatable but can be deadly if not recognized and treated promptly
47 Lightening round….
Rep les are known to carry Salmonella but recent data show that treatment can eliminate Salmonella
Fact or Fiction?
48 Fiction Since 1975, turtles < 4 inches Illegal to sell………….
Reptiles / amphibians often carry Salmonella. Salmonella can get on cages, aquariums, terrariums, and other containers that house them Shouldn’t be allowed to roam freely throughout the house or in areas where food or drink is prepared, served, or stored, such as kitchens, pantries, or outdoor patios Reptiles can’t be ‘cleared’ of Salmonella Caution for children < 5 years of age, older adults, or immunocompromised individuals
Raccoons can make good pets, especially if acquired when they are young
Fact or Fiction?
49 Fiction
Besides being illegal, lots of other reasons not to own Perhaps the most important is because of a type of worm they carry called – Baylisascaris procynosis
Baylisascaris procyonis
Intestinal nematode Natural hosts – adult raccoons Transmission – eggs shed in feces (millions of eggs shed) – require 3-4 weeks to become infectious – ova extremely resistant to dessication/ destruction; may remain viable in the environment for years
50 Male
Female Adult Baylisascaris procyonis
Baylisascaris NLM
Often devastating outcome with death or severe neurologic sequelae
However, a few ‘promising’ case reports – 14 month old boy with NLM from MA, some residual deficits and moderate speech delay but overall good – 4 year old boy from New Orleans, LA with NLM, “full recovery” – Both Rxed with steroids and anti-helminthic
Peters et al., Pediatrics, 2012 Pai et al., Emerg Inf Dis, 2007
51 Baylisascaris procynosis
More severe than Toxocara – larger larvae (1-2 mm) – extensive migration (brain, eye, heart) Clinical – eosinophilic meningoencephalitis – death or long-term DD in children Pathology – deep cerebral white matter granulomas
Parvovirus in children is sometimes acquired from pet dogs
Fact or Fiction?
52 Fiction canine parvovirus type 2b – Highly contagious viral illness that affects dogs – Two forms Diarrhea form Cardiac from Not the same as Human Parvovirus B19
Dogs can sometimes transmit Leptospirosis to people
Fact or Fiction?
53 Fact
Leptospirosis can be transmitted direct contact with urine, bite wounds, ingestion of infected tissue-penetrate skin or mucous membranes Most human hosts associated with water contact ; however reports of acquiring lepto from infected dogs (particularly in vet hospitals) Any dog with acute renal failure; treat as suspect lepto but dogs are often asymptomatic
Ebola virus is considered a zoonotic infection Fact or Fiction?
54 Fact
Summary
Dogs and cats make great pets and are generally safe Although cats are the definitive host for toxoplasmosis, people rarely acquire the infection from their pet cats Rodents can make great pets but need to remember RBF Good flea control will help prevent diseases in pets and people Wild animals never make good pets
55 Relative/hypothetical probability of contracting illness (not real)
The End
56 MRSA in a family and its pet cat
• Healthy (human) female with recurrent deep
abscesses, +MRSA (spa-type t131*) • Family members colonized same MRSA strain • Antiseptic washes and mupirocin nasal ointment Rx to allà family neg but patient remained pos • 3 healthy pet cats at home screened à one pharyngeal culture positive for same MRSA strain
*Rare type of MRSA
-Sing A et al., NEJM, 2008
MRSA in a family and its pet cat
MRSA-positive cat Rxed with topical decolonization (cipro and rifampin) 4 weeks later Sing A,– NewAll familyEng J Med, members 2008 negative – Index patient neg MRSA screen / no more abscesses
Further MRSA screening of cat declined by family
Sing A et al., NEJM, 2008
57 MRSA in a family and its pet cat
This case “illustrates that MRSA transmission occurs between humans and cats” Abscesses in index patient cleared ‘only’ after cat was Rxed Unclear if cat was original source or vice versa
Sing A et al., NEJM, 2008
58