Introduction To Zoonotic Diseases Flashcards
Zoonoses: definition, transmission types
Diseases/infections naturally transmitted between animals and humans
Includes transmission from “animal to man” & “man to animal”
Anthropozoonosis: definition, examples (5)
Animal to human infection
Rabies, brucellosis, cat scratch disease
Bat to human COVID
Pig to human influenza
Zooanthroponosis: definition, examples (3)
Human to animal infection
Tuberculosis to elephants
Influenza to ferrets
Human to mink COVID
Examples of what are NOT zoonoses (4)
Poisoning/envenomation
Bites, scratches
Allergies
Anthroponoses
Situations/places where zoonosis can occur (6)
-Farm sites: farmers, farm help, etc. where people are in close contact with livestock or their byproducts (e.g., milk, placenta)
- Animal processing facilities: workers at slaughterhouses and processing plants
-Forestry/outdoors: people who frequent wildlife habitat for professional or recreational reasons
- Recreation: contact with pets or wildlife in an urban environment
- Laboratories/clinics: health care personnel and laboratory technical specialists who handle specimens, tissues, carcasses
-Emergencies: those affected by catastrophes, refugees, or temporarily living in crowded or high stress situations
Agent: definition, characteristics
Organism causing disease
Can act alone or with other organisms
Infections can be transient or persistent
Reservoir aka
Carrier
Reservoir: definition
Source of persistence in nature and infection in new hosts
Amplifier aka
intermediate host
Amplifier: definition, characteristics
High levels of agent replication
Closer human contact vs reservoir
Asymptomatic infections often
Most commonly associated with vector borne diseases
Amplifier most commonly associated with what kind of diseases
Vector borne
Dead end host: definition, characteristics
Agent doesn’t replicate to level necessary for further transmission (don’t infect feeding mosquitos anymore)
Often asymptomatic infections
Associated with vector borne diseases
Zoonotic infectious agents: bacteria (5)
Anthrax
Brucellosis
Lepto
Plaque
Q fever
Zoonotic infectious agents: viruses (5)
COVID
Influenza
Monkey pox
Rabies
West Nile
Zoonotic infectious agents: fungi (3)
Dermatophytes
Histoplasmosis
Basidiobolus
Zoonotic infectious agents: prions
Mad cow disease
Zoonotic infectious agents: parasites (protozoal)
Toxoplasma
Giardia
3 types of parasites
Protozoal
Helminths
Arthropods
Zoonotic infectious agents: parasites (helminths)
Baylisascaris
Trichinella
Zoonotic infectious agents: parasites (arthropods)
Scabies
Is every animal species associated with a zoonosis
Yes
Dogs and cats are reservoir species for (4)
Rabies, roundworms, ringworm
Cat scratch disease
Livestock are reservoir species for (4)
Salmonella
E. coli
Brucellosis
Q fever
Birds and poultry are reservoir species for (3)
Avian influenza
Chlamydiosis
Cryptococcus
Reptiles/fish/amphibians are reservoir species for (2)
Salmonella
Mycobacterium
Wildlife are reservoir species for (4)
Rabies
Hantavirus
Plague
Tularemia
4 routes of zoonotic disease transmission
Direct contact
Indirect contact
Foodborne
Vector borne
How zoonotic diseases are transmitted: direct contact
Infected tissue
Bite wounds
Body fluids (Urine, feces, saliva ; Milk, semen)
How zoonotic diseases transmitted: indirect contact
Fomites = food and water dishes (objects likely carrying infection)
Aerosol = coughing, sneezing, bedding, dander
How zoonotic disease transmitted: vectorborne
Rodents
Mosquitos
Fleas
Ticks
SIR model of pathogenesis
SUSCEPTIBLE—> incubation period —> INFECTED/symptomatic —> transmission —> RECOVERED, REMOVED OR DEAD (immune, carriers, or remain susceptible)
How many known zoonotic diseases are there
250
Number of national notifiable zoonotic diseases
25
Number of reported cases of rabies per year
55,000
Which disease has the greatest number of reported cases per year
Leptospirosis
Are reported or unreported case numbers higher
Unreported
Number of unreported salmonella cases per year
1 million
Number of unreported campylobacter cases per year
1.3 million
Costs of zoonotic diseases (2)
Cost to human health = lost productivity, loss of life
Economic costs = treatment, import/export restrictions, loss of trade and tourism
Focus of traditional health management
Treating sick animals
Vet called to farm
Directed at medical treatment vs prevention
Herd health management approach focuses on
Prevention = ID risk factors for disease, more proactive
Herd health management approach: definition
Optimizes the health, welfare, and production in a population of animals (e.g., beef or dairy cattle, swine, or poultry) through systematic analysis
of relevant data and through regular objective observations of the animals and their environment, such that informed, timely decisions are made to adjust and improve herd management over time
Herd health management approach: objectives (5)
• Optimize health status by preventing health, production, and reproductive problems
• Optimize productivity by improving herd management practices
• Optimizes animal welfare and ecological quality of the
environment
• Optimize the quality and safety of dairy and meat products
• Optimize the profitability of the enterprise
Which 2 government organizations classify reportable diseases
State department of agriculture
USDA/APHIS
Main responsibilities of state department of agriculture and USDA/APHIS (3)
Animal health and welfare
Classify reportable diseases
Animal import/export requirements
World organization for animal health: responsibilities (4)
Set disease prevention and control measures
Point of contact for disease occurrence
Ensure members have access to necessary tools to respond to disease threats
Foster onehealth approach across borders
Agroterrorism definition
The deliberate introduction of animal or plant disease for the purpose of generating fear, causing economic loss, or undermining social stability
Government agencies/departments responsible for protection against agroterrorism (4)
• Department of Homeland Security
• USDA Animal and Plant Health Inspection Service (APHIS)
• USDA Food Safety Inspection Service (FSIS)
• USDA Agricultural Research Service (ARS)
3 likely agroterrorism agents
Newcastle disease
Rift valley fever
Highly pathogenic avian influenza
3 confirmed cases of agroterrorism
1997 - rabbit hemorrhagic disease virus in New Zealand
1985- screwworm along Mexico/Us border
1952 - milk bush sap poisoned cattle in Kenya
Emerging infection definition
a new or newly identified pathogen or syndrome, or one that has resulted in new manifestations of an infectious disease
Re emerging/resurging infection definition
a previously identified or known
pathogen that is increasing in incidence, expanding to new geographical areas, or affecting new populations or species
General characteristics/trends of emerging diseases (5)
Largely zoonotic
Bacteria or rickettsia
Increasing in frequency
More commonly vector borne and drug resistant
Emerging hotspots in tropical areas
What percent of emerging diseases are due to bacteria
54
Emerging diseases are commonly from what sources
Bacteria
Wildlife
Examples of emerging diseases (5)
Ebola
Campylobacter
Mad cow disease
COVID
E. coli
Examples of re emerging zoonotic diseases (6)
Rabies
West Nile
Giardia
Tuberculosis
Salmonella
Mpox
Sequence of who report to who for zoonotic diseases
Individual —> state —> UDSA —> WOAH
