Public Health Final Exam

define zoonoses

diseases/infections naturally transmitted between animals and humans; includes animal to human and human to animal

define anthropozoonosis + an example

animal to human infection, rabies

define zooanthroponosis + an example

human to animal infection, influenza to ferrets

zoonoses are NOT

poisoning/envonomation, bites, scratches, allergies, anthroponoses (ppl to ppl disease)

6 situations where zoonosis may occur

farm sites→close contact w/ livestock or their byproduct

animal processing facilities→slaughterhouses

forestry/outdoors→frequent wildlife habitat contact

recreation→ contact w/ pets or wildlife in general

labs/clinics→ handling specimens, tissues, carcass

emergencies→ catastrophes/natural disasters, refugees

define agent

the organism causing disease, can act alone or in concert w/ other organisms, infections can be transient or persistent

define reservoir

“carrier”, source of persistence in nature and infection in new hosts, may or may not have symptoms of infection, may be the environment itself

define amplifier

intermediate host, high levels of agent replication, often in closer human contact than a reservoir, asymptomatic infections in many cases, most commonly associated w/ vector borne diseases

define dead end host

agent that does not replicate to the level necessary for further transmission, asymptomatic infections in many cases but in some cases severe disease is possible, often associated w/ vector borne diseases

bacterial zoonotic infectious agents

anthrax, brucellosis, lepto, plague, q fever

viral zoonotic infectious agents

covid19, flu, monkeypox, rabies, west nile virus

fungal zoonotic infectious agents

dermatophytes, histoplasma, basidiobolus

prions zoonotic infectious agents

prion=a misfolded protein that can transmit its misfolded shape onto normal variants of the same protein

mad cow disease

parasitic zoonotic infectious agents

protozoal (toxoplasma, giardia)

helminths (baylisascaris, trichinella)

arthropods (scabies “mange”)

are all animal species associated w/ a zoonosis?

YES, each species is a reservoir species for varying diseases

dogs and cats are reservoir species for what diseases

rabies, roundworm, ringworm, cat scratch disease

livestock is a reservoir species for what diseases

salmonella, e.coli, brucellosis, q fever

birds and poultry are reservoir species for what diseases

avian flu, chlamydiosis, cryptococcus

reptiles, fish, & amphibians are reservoir species for what diseases

salmonella, mycobacterium

wildlife is a reservoir species for what diseases

rabies, hantavirus, plague, tularemia

options for life cycles of zoonotic diseases

single vertebrate host/reservoir species

multiple vertebrate host/reservoir species

more than one vertebrate/invertebrate host/reservoir species

routes of zoonotic disease transmission- direct contact

infected tissue, bite wounds, body fluids

routes of zoonotic disease transmission- indirect contact

fomites from food/water dishes, aerosol

routes of zoonotic disease transmission- foodborne

contaminated food and water

routes of zoonotic disease transmission- vectorborne

rodents, mosquitos, fleas, ticks

do agents vary in their potential to infect humans

yes

what are the transition states of disease transmission

SIR model of pathogenesis

S- susceptible

I- infected/symptomatic

R- recovered, removed, or dead

between S and I = incubation period

I & R= transmission of disease stages

what is the importance of zoonoses

there are over 250 known zoonotic diseases, there are 25 notifiable at a national level, 61% of known human pathogens, 75% of new and emerging infectious diseases

what zoonoses have the most reported cases year worldwide per year

rabies, leishmaniasis, cysticerosis, brucellosis, leptospirosis

\
leptospirosis → 10 million; *the most*

in reported cases of zoonoses in the US in 2015, what disease had the highest amount of cases

salmonellosis, with 55,108 :O

followed by campylobacter with 54,556

estimations including unreported cases increases this to 1 million, and campylobacter to 1.3 million

*rabies had only 2!*

what are the costs of zoonotic diseases

costs to human health

\-lost productivity

\-loss of life

economic costs

\-direct/indirect costs of prophylaxis and tx

\-cost of import/export restrictionos

\-loss of trade and tourism

traditional health management focuses on

treatment of sick animals

\-vet called to farm to tx sick p, directed at medical treatment and less towards prevention

what is the Herd Health Management (HHM) Approach

optimizes the health, welfare, and production in a population of animals (cattle, swine, 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 focuses on

prevention of disease in the herd and minimizing infectious disease

\-based on the identification of risk factors for disease

>agent, animal, environmental

\-more proactive approach to health management

\-does not eliminate traditional management approaches

objectives of herd health management approach

optimizes:

\-health status by preventing health, production, and reproductive problems

\-productivity by improving herd management practices

\-animal welfare and ecological quality of the environment

\-the quality and safety of dairy and meat products

\-the profitability of the enterprise

animal health governance organizations

state department of agriculture, usda/aphis, world organization for animal health

role of state department of agriculture

state vet- dr. ryan walker

animal health & welfare regulations

classifying reportable disease

animal import/export requirements

role of usda/aphis

chief vet officer- dr. rosemary sifford

area vet in charge (AVIC)

animal health and welfare regulations

classifying reportable disease

animal import/export requirements

role of world organization for animal health

director- dr. monique eloit

sets disease prevention and control standards

serves as point of contact for disease occurence

ensures members have access to all the tools necessary to respond to disease threats

foster a one health approach across borders

what is agroterrorism

the deliberate introduction of animal or plant disease for the purpose of generating fear, causing economic loss, or undermining social stability, highly contagious & easy to hide

what departments/agencies are responsible for protection against agroterrorism

department of homeland security

USDA APHIS

USDA FSIS

USDA Agricultural Research Service (ARS)

what are the likely agroterrorism agents

agents listed under the WOAH List A

\-foot and mouth disease

\-african swine fever

\-classical swine fever

\-swine vesicular disease

\-peste des petits ruminants

\-lumpy skin disease

\-exotic bluetongue disease

\-african horse sickness

\-newcastle disease\*\*

\-rinderpest

\-contagious bovine pleuropneumonia

\-rift valley fever\*\*

\-sheep/goat pox

\-highly pathogenic avian flu\*\*

(listed in order of importance)

\*\*= zoonotic disease

1997 confirmed case of agroterrorism

introduction of rabbit hemorrhagic disease virus into new zealand

1985 confirmed case of agroterrorism

introduction of screwworm among livestock near the mexico/us border

1952 confirmed case of agroterrorism

poisoning of cattle in kenya with milk bush sap by political insurgents

define emerging infectious diseases

a new or newly identified pathogen or syndrome, or one that has resulted in new manifestations of an infectious disease

define re-emerging (or resurging) infectious diseases

previously identified or known pathogen that is increasing in incidence, expanding to new geographical areas, or affecting new populations or species

general characteristics of emerging diseases

largely zoonotic, \~54% of them are often bacteria or rickettsia, increasing in frequency, more commonly vector borne & drug resistant, emerging hotspots in tropical areas

define zoon

animal

define nosos

disease

define anthro

human

when an individual vet reports to the state, where does the info go

the state reports to usda, which then reports to the WOAH

why did death rates slowly increase from 1980-2000

in 1978, there was the first HIV outbreak and then there were huge numbers of cases of transmission (via blood transfusion)

what are the factors of disease emergence

genetic/biological factors, physical environment, ecological factors, social/political/economical factors, infectious agents, domestic animals, humans, wildlife

factor of disease emergence: genetic & biological → the why, answer= the how

microbial adaptation and change

host susceptibility to infection

factor of disease emergence: physical environment → the why,

answer= the how

climate & weather

urbanization & land use (there is an increase in world pop living in urban areas, projected to be 60% by 2030) (land use for concentrated animal feeding operations)

factor of disease emergence: ecological → the why, answer= the how

changing ecosystem

human demographics and behavior

factor of disease emergence: social, political, economical → the why, answer= the how

international travel & commerce

technology & industry

breakdown of public health measures

poverty & social inequality

lack of political will

war and famine

intent to harm

global trade in exotic animals

has the total # of fda approved antimicrobial agents for human use increased or decreased over time

decreased

public health measures, statistics

infant mortality

\-1960: us ranked 12th

\-2019: us ranked 33rd

maternal mortality rate (deaths/100k live births)

\-during 1951-3: us ranked 1st

\-2018: us ranked 55th

life expectancy at birth

\-1950: us ranked 7th

\-2020: us ranked 46th

in the 20th century, us life expectancy ==**increased**== by 30 years

\-only 5 of which are attributable to better health care

annual figures of global trade of exotic animals

4 million birds, 640,000 reptiles, 40,000 primates, illegal trade is unknown but guessed to be around 4-6 billion

what are factors that promote zoonoses transmission

frequent contact (ppl-animal, animal-animal, habitat loss, vector expansion)

animal husbandry & health (nontraditional pets, intensive production systems → feedlots)

personal hygiene (lack of)

globalization (increased domestic and intentional travel of ppl animals and products)

number of pet species in the US, increasing on the daily

poultry, with 440 million

followed by cattle at 90 million, cats with less than 70 million, pigs at 66 million, dogs with less than 60 million, and horses at 9 million

what are the strategies for mitigating future disease emergence

**novel vaccines & delivery systems**

**address antimicrobial resistance as a national priority**

**grow one health practitioners and research teams**

\-teach vigilance as well as diagnostics

\-surveil for emergence in developing regions

**build predictive capability**

\-sustains changes in political will better than reactionary capabilities

**reduce effects of poverty and inequality**

\-ensure prevention and response utilize current technology

crude death rate for infectious disease trends

was trending downwards/decreasing, peaked at the influenza pandemic, decreased again thanks to end of transmission of plague + use of abx (penicillin), but eventually increased post 1980 due to HIV transmission

human focused prevention of disease strategies focuses on protecting who

primary concern= high risk groups

\-immunocompromised, those with hiv/aids, hx of cancer or chronic disease, elderly, pregnant woman, children, frequent travels

\-occupation (making them high risk) → livestock producers/stockmen, vets, zookeepers, lab techs

human focused prevention of disease strategies

good hygiene, PPE/barrier precautions, food preparation, avoiding contact w/ secretions and excretions of pets and other animals, vector mitigation (preventing exposure), avoid problem foods

animal focused prevention of disease strategies

control programs (wellness exams of p, vax, restrictions)

mitigation of dietary factors (hunting/raw meat diets)

parasite & vector control

screening & treatment (for intestinal parasites for ex)

have rabies cases in dogs/cats/cattle increased or decreased

decreased!

site specific focused prevention of disease strategies

**public settings**

\-childcare/schools, pet stores, petting zoos

>consider handwashing, plates and cups, contact w/

ground

\
**health care facilities: therapy animals**

\-enroll in animal assisted intervention programs to help ensure human and animal safety

\-vaccinated, healthy, free of internal and external parasites, eating commercial, cooked food

\-society for healthcare epidemiology of america published guidelines (no standards exist for zoonotic disease prevention)

\-avoid contact w wounds or medical devices

\
**veterinary clinics & hospitals**

\-NASPHV 2015 compendium of vet standard precautions

\-accessible handwashing & available PPE

\-environmental infection control

\-special attention to bites/scratch preventions

\-employee health plan w/ well defined policies

when a client is suspected to have a zoonotic disease, who do you report it to

their healthcare provider

when a client is suspected to have a zoonotic disease, which patients require that you communicate directly w/ the healthcare provider

immunocompromised, children, and nursing facilities clients

what is the primary cause of immunodeficiency

congenital acquisition (\~1 in 500 ppl)

\-100s of cases identified

\-manifested by recurrent or persistent infections or developmental delay

what is the secondary cause of immunodeficiency

immune system damaged later in life

\-due to age, malnutrition, infection/disease, medical treatments

immunocompromised populations: children

children under 5 are at risk

makes up \~6.5% of us population

they have poor hygiene → always something in their mouth

immunocompromised populations: eldery

adults older than 65

makes up 13% of us population

less than 45% own pets

immunocompromised populations: pregnant women

they experience immune changes

immunocompromised populations: hiv/aids individuals

1\.1 million + ppl in the us

good news- life expectancy has increased

bad news- more time for zoonotic susceptibility of the disease

immunocompromised populations: chronically diseased

cancer and diabetes hinder an effective immune response

55% of ppl who experienced chemotherapy own pets

immunocompromised populations: long term medical treatments

individuals who have had cancer chemotherapies or antiinflam drugs long term tend to be classified as immunocomp & easily susceptible to disease

what age of animals are more likely to be infected/infectious w/ zoonotic disease

young animals

what are the high risk species that are more likely to carry zoonotic disease

reptiles, some birds, non-human primates, exotic species, wildlife

consider those animals that also dont bite/scratch

special risk situations of human-animal contact

during routine care

\-raw meat diets promote shedding of salmonella and e.coli

\-fecal contact while cleaning litter box (toxoplasma)

\-cleaning reptile habitats, aquariums, and bird cages

animals in public settings

occupational exposures

animal bites

\-children are at greatest risk

what are the important zoonoses for immunocompromised clients

bartonella henselae (cat scratch disease)

toxoplasma gondii (toxoplasmosis)

methicillin resistant staphylococcus aureus (mrsa)

chlamydophila psittaci (avian chlamydiosis)

mycobacterium speciese (tb, leprosy, etc)

lymphocytic choriomenigitis virus (LCM)

what are prevention methods for preventing zoonotic disease in the immunocompromised client

urge consultation w/ a health care provider

discuss human implications of zoonotic dx with owners

specific guidance topics (via pamphlets, videos, etc)

should immunocompromised clients keep their pets

yes! in most cases

benefits to immunocompromised clients keeping their pet

physical and mental benefits

\-increased companionship

\-decreased depression, anxiety, triglycerides, blood pressure, loneliness (in general)

\-increased physical activity and socialization (for the elderly)

\-increased confidence and happiness (in children)

how to prevent zoonotic disease in pets

via diet, vet care, and grooming + flea control

diet

\-feed a reputable commercial diet (no raw diet or milk)

\-provide clean fresh water

\-discourage/prevent hunting and keep cats inside

vet care

\-annual exams

\-new pet exam asap

\-utd on vax, deworming, routine care

\-examine and treat ill pets asap

grooming + flea control

\-bathe brush and comp prn

\-keep environments, bedding, feeding areas clean

risks of immunocompromised clients keeping their pet

more susceptible to opportunistic pathogens

disease may be more virulent or present in ppl

affected person is likely to transmit the disease to others

what are the 2 major classifications of immunodeficiency + who may also be considered immunocomp

primary (congenital) & secondary (hiv, cancer)

elderly, pregnant women, children

according to the az health department, what zoonotic disease is investigated the most

rabies @ 39%

dollowed by brucellosis and hanta virus at 11% each

arizona one health focuses on

\-the presence of these zoonotic diseases in AZ, which are exacerbated by diversity in wildlife species, disparities across communities, extreme climates, varying topography, and close proximity to an international border

\-extreme weather events (flash floods, wildfires, drought, dust storms) encouraging animals to seek refuge in environments closely inhabited by people

tularemia facts

\-occurs in north america, europe, soviet union, china, japan

\-occurs year round in the US, incidence is higher in adults in early winter due to contact with rabbits during hunting season

\-in children, it is more common during the summer when tick & fleas are abundant

\-accidental transmission in lab settings is poss (third most common reported lab associated bacterial infection)

tularemia in az

\-circulates naturally among rabbits and rodents and usually found in areas above 3,000 feet

\-cases in az have been related to exposure to a rabbit or rabbit carcass, a dog that was exposed to a rabbit, skinning an elk, and poss insect bites

tularemia agent

Francisella tularensis

\-a gram negative bacterium

***considered a potential bioterrorism weapon***

tularemia epidemiology

**incubation period**: avg 3-5 days, but ranges from 1-14 days

**period of communicability**: not directly transmitted from person to person but the drainage from lesions are potentially infectious; flies can remain infectious for 14 days and ticks can remain infectious throughout their lifetime

**susceptibility & resistance:** all ages are susceptible and long term immunity follows infection however reinfection has occured and been reported

tularemia clinical diagnosis

clinical dx is supported by evidence or hx of a tick or deerfly bite, exposure to tissues of a mammalian host of Francisella tularensis, or exposure to potentially contaminated water

symptoms of tularemia

sudden fever, chills, headaches, diarrhea, muscle aches, joint pain, dry cough, progressive weakness, pneumonia, chest pain, bloody sputum

without treatment: infection could progress to respiratory failure, shock, and death

symptoms are dependent upon the site of infection and route of transmission

glandular form: enlarged lymph nodes draining form inoculation site

pneumonic form: severe, acute pneumonia

typhoidal form: severe fever, chills, malaise

rodents are rarely symptomatic

what is the differential diagnosis of tularemia

plague

distinct clinical forms of tularemia

ulcerglandular

glandular

oculoglandular

oropharyngeal

pneumonic

typhoidal