From Greek: Zoon = _______
animal
From Greek: Noses = _______
disease
Zoon_ _ _ _ = singular
zoonosis
Zoon_ _ _ _ = plural
zoonoses
What is a zoonotic disease?
Diseases and infections which are naturally transmitted from animals to humans.
What is reverse zoonosis?
when human gives to animal
What is Xenozoonosis?
not direct transmission route, blood transfusion, etc
What is Epidemiology?
the branch of medicine that deals with the incidence, distribution, and possible control of diseases and other factors relating to health.
about __% of pathogens are zoonotic
60%
about __% of emerging diseases are zoonotic
75%
How many zoonotic diseases exist?
more than 250
Transmission ____________.
varies
Risk is ______ from lab animals
low
People at risk for zoonotic diseases? (x7)
1. Newborns/children
2. Immuno-compromised: diabetics, AIDS
3. Elderly
4. Slaughterhouse workers: touching animal and animal biproducts
5. Farmers/staff
6. Veterinarians/staff
7. Pet owners
Factors that promote zoonoses? (x5)
1. Frequent contact with domestic animals
2. Overlap with wildlife habitat: hunt/hike
3. Poor animal sanitation
4. Poor personal hygiene
5. Intensive livestock production
What is a host?
An organism that is infected with or is fed upon by a parasitic or pathogenic organism. The host does not benefit and is often harmed by the association.
What is a reservoir?
Any person, animal, plant, soil or substance in which an infectious agent normally lives and multiplies. The reservoir typically harbors the infectious agent without injury to itself and serves as a source from which other individuals can be infected.
The ___________ _____________ primarily depends on the reservoir for its survival.
infectious agent
It is from the ___________ that the infectious substance is transmitted to a human or another susceptible host
reservoir
What is a vector?
an organism that does not cause disease itself but which spreads infection by conveying pathogens from one host to another.
Examples of a vector? (x7)
mosquitos, mice, raccoons, birds, bats, fleas, ticks
What is an agent? examples?
causative agent. often bacteria/virus/parasite/fungus
What is transmission?
initial transport of a pathogen to the host; must be transmitted from one host to another.
Direct vs. Indirect transmission?
#NAME?
What is a diagnosis?
the identification of the nature of an illness or other problem by examination of the symptoms and/or signs and/or diagnostic testing
What is a differential diagnosis?
other diseases or illnesses that it could be
What is a prognosis?
the likely course of the disease
What is a sign?
Any objective evidence of disease, as opposed to a symptom, which is, by nature, subjective.
What is a symptom?
Any subjective evidence of disease.
Animals can show ________.
signs
Humans can show _________.
signs and symptoms
What is Morbidity?
incidence of the disease or the rate of sickness (how often and how quickly)
What is Mortality?
number of deaths in a given time (death rate)
Tx stands for?
treatment
Hx stands for?
History
Px stands for?
prognosis
Dx stands for?
Diagnosis
Abx stands for?
antibiotics
DDx stands for?
Differential Diagnosis
What are the four Etiological Classifications?
� Viral
� Bacterial
� Parasitic
� Mycotic (fungal)
Viral Zoonoses? (x3)
� Contagious Ecthyma
� Lymphocytic Choriomeningitis
� Acute Viral Encephalitis (Rabies)
Bacterial Zoonoses?
� Avian Chlamydiosis
� Salmonellosis
Parasitic Zoonoses? (x1)
Toxoplasmosis
Mycotic Zoonoses? (x1)
Dermatophytosis
Contagious Ecthyma: common name?
Orf
Contagious Ecthyma: Agent?
� is _______. will _______ on hair and skin of animal.
DNA virus (Parapoxvirus). Is hardy; persist on hair and skin of animals
Contagious Ecthyma: Reservoirs?
Domestic and wild ungulates (hoof stock)
What is the technical term for hoof stock?
ungulates
Contagious Ecthyma: Occurence?
� common or uncommon?
� worldwide?
Incidence uncommon BUT is worldwide, especially where sheep and goats are raised.
Contagious Ecthyma (Human cases) are most common in ________________.
New Zealand
Contagious Ecthyma is an __________________ disease.
occupational
Contagious Ecthyma: Transmission?
� direct vs indirect?
� Ewes that nurse infected lambs: _______________________
� Direct contact: touching directly. lesions and/or MM infected animals
� Indirect contact: knives, shears
� Ewes that nurse infected lambs: teat and udder infections
Contagious Ecthyma in Animals: Signs? (x2)
� Pustules on skin, eyelids, ears, lips, and nostrils
� Lesions - painful and can interfere with feeding
Contagious Ecthyma in Animals: Treatment? (x2)
� Supportive therapy
� Antibiotics (Abx) only if secondary bacterial infection
Contagious Ecthyma in Animals: Diagnosis?
Usually by clinical signs. Not concrete diagnosis
Contagious Ecthyma in Animals: Prognosis?
� Morbidity ?
� Mortality?
� can lead to a _____ ______ _____ because of ________.
� Morbidity (incidence) is high
� Mortality (death) is low
� Secondary bacterial infection or maggots
Contagious Ecthyma in Humans: Signs and Symptoms? (x2)
� Large pustular region at site of virus entry, Usually on hands, arms, or face. Very painful; eventually oozes
� Secondary bacterial infection
Contagious Ecthyma in Humans: diagnosis? (x2)
� Physical exam
� patient History
Contagious Ecthyma in Humans: Treatment? (x2)
� no specific treatment. Supportive therapy
� Abx to treat bacterial infections
Contagious Ecthyma in Humans: Prognosis?
� will resolve in ______ to _______ ________.
� can spread to ________.
� Most cases resolve in 2-4 weeks
� Can spread to eyes
Contagious Ecthyma: prevention? (x2)
� Good personal hygiene
� Good animal husbandry practices
Contagious Ecthyma: vaccine?
� Crude live vaccine for lambs (can get it from vaccine). In general don't do it, but new Zealand, etc. might
Contagious Ecthyma: reporting?
not required
Etiological Classification of Contagious Ecthyma
viral
Lymphocytic Choriomeningitis: abbreviation?
LCM
Lymphocytic Choriomeningitis: agent?
Lymphocytic Choriomeningitis Virus (LCMV)
Lymphocytic Choriomeningitis: reservoir?
� Wild house mice
� Domestics: mice go into cage and spread it
Lymphocytic Choriomeningitis: occurence?
� worldwide?
� ____________ _______________ making hard to determine incidence rates or prevalence by geographical regions
� Europe, Americas, Australia, Japan
� Under-reported making hard to determine incidence rates or prevalence by geographical regions
Lymphocytic Choriomeningitis: transmission?
� found in?
� Humans & pet rodents?
� Virus found in saliva, urine, and feces of infected wild mice. Shed virus for duration of life while remaining sub-clinical
� Other rodents, especially hamsters, not natural reservoir BUT can become infected
� Humans contract more from wild mice than pe
Lymphocytic Choriomeningitis most common transmission route?
in utero
Lymphocytic Choriomeningitis in animals: signs? (x4)
� Naturally infected mice show no clinical signs
� Mice infected in utero, Often runted
� Adults: acute immune-mediated diseases
� Hamsters: Weight loss, tremors, seizures
Lymphocytic Choriomeningitis in animals: Diagnosis? (x2)
� Serology/bloodwork
� PCR (polymerase chain reaction)
Lymphocytic Choriomeningitis in animals: Treatment & prognosis
� Supportive therapy in the case of a pet rodent
� High mortality
Lymphocytic Choriomeningitis in humans is a _____________ illness
Bi-phasic febrile illness
Lymphocytic Choriomeningitis in humans: signs and symptoms STAGE 1
� lasts how long?
� common symptoms?
� uncommon symptoms?
Initial phase
� Last up to a week
� Fever, malaise, lack of appetite, muscle aches, headache, nausea, vomiting
� Less frequently - sore throat, cough, joint pain, testicular pain, salivary gland pain
Lymphocytic Choriomeningitis in humans: signs and symptoms STAGE 2
Secondary phase
� Following a few days of recovery - symptoms of meningitis; characteristics of encephalitis
� Hydrocephalus
� Myelitis
� Myocarditis
What is Encephalitis?
inflammation of brain
What is Hydrocephalus?
water on brain
What is Myelitis?
spinal cord inflammation
What is Myocarditis?
heart muscle inflammation
Lymphocytic Choriomeningitis in humans: onset?
Onset 8-13 days after exposure
Lymphocytic Choriomeningitis in humans: Diagnosis STAGE 1 (x3)
� leukopenia (decreased WBCs)
� thrombocytopenia (decreased platelets)
� liver enzymes elevated
What is leukopenia?
decreased WBCs
What is thrombocytopenia?
decreased platelets
Lymphocytic Choriomeningitis in humans: Diagnosis STAGE 2 (x2)
� leukocytosis (increased WBCs)
� decrease in glucose levels in cerebrospinal fluid (spinal tap)
What is leukocytosis?
increased WBC
Lymphocytic Choriomeningitis in humans: Treatment (x3) & Prognosis
� Hospitalization and supportive therapy based on severity
� Anti-inflammatory drugs- steroids
� Anti-viral drugs
� Mortality less than 1%
Etiological Classification of Lymphocytic Choriomeningitis?
viral
Lymphocytic Choriomeningitis in humans: Prevention (x2)
� Avoid contact with wild mice
� Take precautions handling pet rodents
Acute Viral Encephalitis: common name?
Rabies
Acute Viral Encephalitis: Agent?
� RNA virus
� Lyssavirus
Acute Viral Encephalitis: Reservoir? (x6)
Dogs, fox, coyotes, skunks, raccoons, bats, etc.
Acute Viral Encephalitis: Occurence/Mortality
� Worldwide?
� ____-____deaths/year mostly in _____________ _______________.
� Worldwide in humans
� 40-70K deaths/year mostly in developing countries
Acute Viral Encephalitis: Transmission?
� what are the two cycles?
� Virus is abundant in __________.
� Most cases caused by _____________________. can be ______ or ______.
� Virus can be _____________. Example: ___________
� Two Cycles: urban and sylvatic
� Virus is abundant in saliva
� Most cases caused by bite from infected animals BUT indirect or direct
� Virus can be aerosolized - ex: bat caves
Acute Viral Encephalitis: Transmission? Urban
transmitted by dogs; accounts for most human cases
Acute Viral Encephalitis: Transmission? Sylvatic
circulates among wild carnivores and bats; causes spillover infections of dogs, cats, livestock
Acute Viral Encephalitis in Animals: two types
Furious & Paralytic
Acute Viral Encephalitis in Animals: Furious
� Signs?
� occurs in?
� dogs, cats, wild mammals
1) Agitated, restless, excitable in early stage
2) Aggressive phase follows. bites others and self
3) Profuse salivation (paralysis of throat muscles); bark turns to a hoarse growl
4) Convulsions and paralysis occur before death
Acute Viral Encephalitis in Animals: Paralytic
� Signs?
� occurs in?
� cattle
1) Initially muscles of head and neck affected
2) Difficulty swallowing
3) Paralysis spreads to extremities - generalizes - death follows
Acute Viral Encephalitis in Animals: Diagnosis
� Behavioral changes; history
� Immunofluorescence on brain tissue- after euthanasia
Acute Viral Encephalitis in Animals: Treatment
Euthansia
Acute Viral Encephalitis in Humans: Incubation
Incubation period variable - onset 3-8 weeks after exposure up to years later
Acute Viral Encephalitis in Humans: Signs and Symptoms
� Discomfort and irritation in area of bites
� Sensory changes, apprehension, headaches, low grade fever; lethargy
� Salivation increases
� Paralysis - not wanting to drink or swallow water. Convulsions and other mental disturbances are terminal events
Acute Viral Encephalitis in Humans: Prognosis
� Death from resp failure 2-8 days after onset
Acute Viral Encephalitis in Humans: Diagnosis
� Presumptive Dx - immunofluorescence of skins sections from back and neck, not always accurate
� Post-mortem exam and testing of brain tissue
Acute Viral Encephalitis in Humans: Treatment
� Almost always fatal!
� Once clinical disease has developed there is not effective Tx options
� Supportive therapy
Acute Viral Encephalitis: Prevention for Animals
� Pre-exposure vaccine
� Rabies laws are state and county contingent
Acute Viral Encephalitis: Prevention for Humans
� Pre-exposure vaccine
� Post-exposure vaccine
Acute Viral Encephalitis: report?
must report!
Etiological Classification of Acute Viral Encephalitis?
Viral
Etiological Classification of Toxoplasmosis?
parasitic
Scientific Name of Toxoplasmosis Agent?
Toxoplasmosis gondii
Toxoplasmosis: Agent?
Toxoplasmosis gondii: obligate intra-cellular sporozoan parasite
Toxoplasmosis: Reservoir?
intermediate hosts?
� Domestic cats only known definitive host
� Sheep, goats, swine, cattle, and chickens - intermediate hosts that carry infective stage encysted in muscle tissue
Toxoplasmosis: Occurrence?
� Worldwide
� Livestock - depends on # cats in pasture (too many is bad idea)
� Up to ______% human adults seropositive (exposed to it)
� _____% of domestic cats in some countries are seropositive
� Up to 70% human adults seropositive (exposed to it)
� 60% of domestic cats in some countries are seropositive
Toxoplasmosis: Transmission in Animals?
� Other animals become infected when consume infected soil or contaminated material
Toxoplasmosis: Transmission in Humans?
� Primary infection/transmission - eating raw/undercooked meats (esp pork or mutton); fecal-oral route
� Congential infection/transmission - transplacental; primary infection during pregnancy; parasite infects fetus; highest risk of contraction 1st and 2n
Toxoplasmosis in Animals: signs?
� Subclinical w/little morbidity or mortality in most
� Sheep - abortion; congenital dz that results in fetal mortality
� Cats - subclinical BUT kittens - diarrhea, hepatitis, pneumonia
Toxoplasmosis in Animals: diagnosis? (x2)
� Fecal floats
� Serological tests for some species (cats)
Toxoplasmosis in Animals: treatment? Prognosis?
� None if subclinical
� Supportive therapy for kittens
� Abx (especially sulfur drugs) to inhibit repro
� After primary infection - cat sheds oocysts in feces for 1-2 weeks
� Oocysts become infective 1-5 days after being passed; can survive in soil for ab
Toxoplasmosis in Humans: Signs and symptoms
� Immunocompetent adults - asymptomatic; sometimes mono-nucleosis type illness
� Oocysts can stay in muscle tissue- reactivate if become compromised
Cerebral toxoplasmosis - AIDS patients; _____ die
� Cerebral toxoplasmosis - AIDS patients; 10% die
Congenital Toxoplasmosis
� what is it?
� 1st trimester: _____ fetuses become infected; _____ severe
� 2nd trimester: ____ fetuses become infected; ____ severe. what happens?
� 3rd trimester: what happens
� 1st trimester - 17% fetuses become infected; 80% severe
� 2nd trimester - 25% fetuses become infected; 30% severe; abortion or premature birth
� 3rd trimester - fewer cases; CNS and eye infections/deformities; encephalitis; hydrocephalus; blindness; men
Toxoplasmosis in Humans: Diagnosis
� Clinical signs/history of exposure
� Serology tests
Toxoplasmosis in Humans: Treatment
� None for healthy people
� Pregnant woman with primary infections - special drug to prevent fetal infection
�Infants/immunocompromised - folic acid plus anti-toxoplasmal drugs
Toxoplasmosis Prevention
� Wash hands after cleaning litter boxes, gardening wear gloves
� Pregnant woman and immunocompromised - serology done to see if they have a titer against Toxo - if not, avoid handling cat feces, eating undercooked or raw meat
Toxoplasmosis: Reportable? Vaccine?
no. no
Etiological Classification of Avian Chlamydiosis?
Bacterial
Scientific name of Avian Chlamydiosis?
Ornithosis/Psittacosis
Avian Chlamydiosis: agent?
� Chlamydophila psittaci
� Obligate, intra-cellular gram negative bacteria
� Unique biphasic repro cycle - only one phase is infectious
Avian Chlamydiosis: agent scientific name?
Chlamydophila psittaci
Avian Chlamydiosis: reservoir?
Birds - especially psittacines (parrot); doves, pigeons, poultry
Avian Chlamydiosis: occurence?
� ___% wild psittacines
� ____-___% - feral pigeon pop. may be carriers
� Worldwide
� 1% wild psittacines
� 50-90% - feral pigeon pop. may be carriers
� Exotic bird owners/breeders, zoo staff, avian quarantine station workers
Avian Chlamydiosis: Transmission?
� Dried feces/nasal secretions and feather dust - aerosolized
� Cleaning cages
� Sneezing and wing flapping
Avian Chlamydiosis in Animals: Signs
� Peracute, acute, chronic strains
� Subclinical carriers
� Depression, anorexia, yellow/green diarrhea, conjunctivitis: eyes infected looking, nasal discharge, respiratory issues
Avian Chlamydiosis in Animals: Diagnosis
� Difficult depending on strain and stage
� Dead birds - impression smears of organs
� Live birds - ELISA; cultures (fecal and oral); may be negative if early stage of dz
Avian Chlamydiosis in Animals: Treatment & Prognosis
� Morbidity and mortality depend on strain
� Abx - clinical cases; sometimes longer than 45 days
� Supportive therapy
Avian Chlamydiosis in Humans: Signs and Symptoms
� Incubation 1-4 weeks
� Onset sudden or gradual
� Fever, chills, headache, muscle aches, URI, LRI
� Elderly - more severe. Such as encephalitis, hepatitis, arthritis, thrombophlebitis (vessels in legs swell. VERY painful)
Avian Chlamydiosis in Humans: Treatment and Prognosis
� Most cases _______, recovery in__________ w/ Tx
� Fatality rate ____________
� Most cases mild, recovery in 7-10 days w/ Tx
� Fatality rate less than 1%
� Abx
� Supportive therapy
Avian Chlamydiosis in Humans: Diagnosis
� Hx (history): do they have birds?
� Serology
� Cultures - blood or sputum (saliva)
Avian Chlamydiosis: Prevention
� 30 day quarantine - only rules out New Castle Dz
� 30 day Won't rule out Ornithosis - Infected birds can look healthy but shed dz
� Masks, gloves, protective clothing
� Cage papers - wet with ammonia, away from birds first.
Avian Chlamydiosis: vaccine, report?
� No vaccine for birds or humans
� MUST report to local health authorities
Etiological Classification of Salmonellosis
bacterial
Salmonellosis: Disease vs. Bacteria?
Disease (salmonellosis) vs bacteria (salmonella)
Salmonellosis: Agent
� Rod shaped, gram negative bacteria
� Many different strains named according to area first isolated
Salmonellosis: Agent scientific name
Salmonella enteritidis
Salmonellosis: Reservoir
� Warm AND cold blooded animals
� Domestic AND wild
� Reptiles - turtles, snakes, iguanas - subclinical carriers
� Chicks
Salmonellosis: Occurence
� Common in humans and animals; worldwide
� Human - food-borne or water-borne
� Major cause of GI illness/diarrhea
� Highest incidence- infants, young children, immunocompromised, elderly
� Occupational exposure
Salmonellosis: Transmission
� Consumption of contaminated foods (poultry, eggs, milk)
� Fecal-oral route
� Indirect contact - touching contaminated food/water bowls
� Bacteria can remain viable for months in dried feces
Salmonellosis in Animals: signs
� Clinical - weakness, fever, recumbency, diarrhea
� Young animals more often. Ex: calves
� Chronic carrier states (reptiles) - fecal carriage rates exceed 90%
Salmonellosis in Animals: diagnosis
� Clinical - isolate organism from blood or internal organs at necropsy
� Chronic carrier - cultures from rectum, cloaca, feces
Salmonellosis in Animals: treatment
� Clinical only - Abx; supportive therapy
Salmonellosis in Humans: signs/symptoms & prognosis
� Acute enterocolitis within 12-36 hours after ingestion
� Headache, abdominal pain, diarrhea, nausea, sometimes fever
� Most cases resolves untreated in a few days
� Rarely fatal except children, elderly, immunocompromised
� Meningitis and/or septicemia
Salmonellosis in Humans: Diagnosis
� Fecal cultures
� Blood if septic
Salmonellosis in Humans: Treatment
� Rarely give _____ . they ______________
� ____ if severe
� ____________________ - hydration!
� however, no ________________ because __________________________________________.
� Rarely Abx - prolong shedding
� Abx if severe
� Supportive therapy - hydration!; however no anti-diarrheals because you want disease to pass as quickly as possible.
Salmonellosis: Prevention
� HANDWASHING!!!!!!!!!!!!!
� Gloves!!!!!!!!!
� Young children, pregnant woman should NOT handle reptiles or young chicks
Salmonellosis: Report?
must report to local health authorities
Dermatophytosis: Etiological Classification?
Mycotic
Dermatophytosis: Common name
Tinea/Ringworm
Dermatophytosis: Agents?
Microsporum canis, Trichophyton mentagrophytes, Trichophyton verrucosum
Dermatophytosis Agents: Trichophyton mentagrophytes. Is what?
Ringworm of beard
Dermatophytosis Agents: Microsporum canis
Humans and animals; usually scalps or bodies of people
Dermatophytosis Agents: Trichophyton verrucosum
Face and upper body
Dermatophytosis: Reservoir for Canis?
Canis - carried by dogs and cats
Dermatophytosis Reservoir for Mentagrophytes:
Mentagrophytes - wild mice and rats; dogs; cats; horses; sheep; rabbits; guinea pigs
Dermatophytosis Reservoir for Verrucosum?
Verrucosum - cattle; sheep; other ruminants
Dermatophytosis: Occurence?
� Worldwide (human and animal)
� occupational
Dermatophytosis: Transmission
� Direct or indirect contact
Dermatophytosis in Animals: Signs
� Canis - 90% of cats no visible lesions - BUT if they do - on face and paws; dogs anywhere on body
� Cattle - small grayish/white scaly patches with hairloss on face/head (thickens/scaby)
Dermatophytosis in Animals: Diagnosis
� UV light on hairs: will be fluorescent
� Culture hairs
Dermatophytosis in Animals: treatment
� Betadine
� Topical
� Oral
Dermatophytosis in Humans: signs and symptoms
� Scaly patches, baldness, brittle hair
� Raised red circular lesion
Dermatophytosis in Humans: diagnosis
� Same as in animals
Dermatophytosis in Humans: treatment
� Same as in animals
Dermatophytosis: Prevention
� Avoid contact
� Hygiene!
Dermatophytosis: Vaccine? reportable?
� yes, for cats and cattle
� not reportable.
The Five Stages of Zoonotic Diseases: Stage 1
The pathogen is present in animals, but does not effect humans under normal conditions.
Stage 1 Example?
Feline distemper
The Five Stages of Zoonotic Diseases: Stage 2
The pathogen can be transmitted from animals to humans, but it cannot spread from human to human.
Stage 2 Example?
Nipah Virus
The Five Stages of Zoonotic Diseases: Stage 3
The pathogen can be transmitted from animals to humans and can pass between humans. However, the pathogen is not well adapted to humans and the pathogen will die out after a few cycles of transmission.
Stage 3 Example?
Ebola Virus
The Five Stages of Zoonotic Diseases: Stage 4
The pathogen can be transmitted from animals to humans and can pass between humans. It can adapt to living in humans for long periods of time without going back to animal hosts.
Stage 4 Example?
Cholera
The Five Stages of Zoonotic Diseases: Stage 5
A pathogen that exclusively infects humans. The pathogen may have co-evolved with humans or colonized humans recently and evolved into a specialized human pathogen.
Stage 5 Example?
HIV