What is a disease?
- A specific disorder or illness
- “Not at ease”
A disease with a living agent is a/an ________ disease.
Infectious
A disease with a nonliving agent is a/an __________ disease.
Non-Infectious
What are five categories of non-infectious diseases?
- Nutritional
- Metabolic
- Trauma
- Toxic Materials
- Congenital Defects
What are six types of infectious disease agents?
- Bacteria
- Virus
- Prions
- Protozoa
- Fungi
- Parasites
What is the infectious disease process?
- Enter Host
- Multiply
- Evade hose defenses
- Harm Host
What are three disease determinants?
- Environment
- Host
- Pathogen (the agent)
Genotype, species, age, and breed are examples of the ________ disease determinant.
Host
Virulence and pathogenicity are characteristics of the ________ disease determinant.
Agent
Location, climate, housing, and management are examples of the __________ disease determinant.
Environment
_________ is the severity of the disease or degree of pathogenicity.
Virulence
What is the ability to cause disease in certain environments or at a certain temperature?
Pathogenicity
For an infectious disease, what does it mean to be contagious?
Animal to animal transfer
For an infectious disease, what does it mean to be non-contagious?
Environmental to animal transfer
What are four portals of entry for a disease?
- Ingestion
- Inhalation
- Cutaneous penetration
- Ascending infection
What are two indirect transmissions of disease, and two direct transmissions of disease?
- Vectors 1. Cough
2. Fomites 2. Touch
What are vectors?
Organism that transmits a particular disease or parasite from one animal to another (mosquito)
What are Fomites?
Inanimate objects that transmit a particular disease for parasite from one animal to another (boots).
What are demics?
Relating to a population or area
What is it called when the rate of disease in a population is greater than expected?
Epidemic
__________ is when a disease is maintained at a relatively constant rate in the population without the need for external input.
Endemic
What is an epidemic of worldwide distribution called?
Pandemic
The host parasite interaction in which neither parties are harmed and one may benefit is called what?
Commensalism
The host parasite interaction in which one organism lives at the expense of another is called what?
Parasitism
The host parasite interaction in which both organisms benefit is called what?
Mutualism
For parasites to be successful, they must _______ with the host.
Co-evolve
What is the objective of pathogens?
To reproduce
What is Infectious Dose (ID)?
The minimal number of pathogens needed to establish a disease
What is ID50?
The number of organisms required to produce an infection in 50% of the test animals.
What is Lethal Dose 50 (LD50)?
The number of organisms or toxin required to cause death in 50% of the test animals
_________ Pathogens are associated only with disease.
Obligate
_________ or _________ pathogens are associated with the normal flora of pathogens in the body.
Opportunistic or Potential
Why is Mannheim Hemolytic an opportunistic pathogen?
Is it found in the normal flora of pathogens in the nasal cavity of healthy cattle. However, it can cause shipping fever when the host is compromised.
The normal flora of bacteria is greater than the number of cells in the body. What is something that can upset the normal flora?
Antibiotics
Pathogenic Microbes that are characterized by frontal assault have what?
- short incubation
- rapid clinical signs
- intimate transmission
Pathogenic microbes that are characterized by stealth assaults have what?
- Lengthy incubation
- slow onset of signs
- Environmental transmission
In humans, what is an example of a pathogenic microbe with a stealth assault?
-HIV
In a final (definitive) host, what happens to the parasite?
It reaches sexual maturity or replicates
A ________ parasite host is one that is essential for the lifecycle of the pathogen and is a temporary environment for development.
Intermediate
A _______ parasite host harbors pathogens that infect others.
Reservoir
What is immunity?
The ability of the body to defend against foreign micro-organisms.
What are the two types of immunity?
Adaptive and innate
Adaptive immunity can be subdivided into two categories. What are they?
Natural and artificial
Natural and artificial adaptive immunity can each be further divided into two subcategories. What are they?
Passive and Active
Give an example of passive natural adaptive immunity?
- maternal (question on notes)
Give an example of active natural adaptive immunity.
You get the infection once, and build up resistance to it.
Give and example of adaptive artificial passive immunity?
Cow passes antibodies to calf through mile that were supplemented to her.
Give an example of adaptive artificial active immunity?
Immunization through vaccination
_______ immunity is the first line of defense that you are born with. It is inherent to the host and no prior exposure to disease is needed to have this immunity.
Innate
_______ immunity is attained due to exposure to disease.
Acquired/Adaptive
What is an example of innate immunity dealing with physiologic barriers?
-pH of the stomach, body temperature
What is an example of innate immunity dealing with anatomic barriers?
Epithelial surfaces (skin and hair)
What is an example of innate immunity dealing with mechanical barriers?
Urinary pH and flushing action
What is an example of innate immunity dealing with phagocytic barriers?
Macrophages and neutrophils
What are examples of innate immunity dealing with inflammatory barriers?
Dilated leading blood vessels allow delivery of inflammatory cells and proteins to the site of injury/infection
What are examples of dermal immunity? Is this immunity innate or adaptive?
-Cell turnover
-pH
-Proteins/lipids
Innate
Nasal hairs, turbulence, and much-ciliary escalator are all examples of what body system’s immunity? Is this adaptive or innate?
- Upper Respiratory
- Innate
What parts of the body have a normal flora of bacteria?
Gut, dermal, vagina
What does the normal flora do in the body?
- Occupies attachment sites
- Produce by-products that are competitive
Where in the body does the flushing action take place?
Urinary tract, mammary gland, nasal secretion
Where in the body does the pH help keep infection out?
Mouth, urine, and stomach
What are the secretory products of the body?
- Mucous
- Enzymes
- Inron Chelators
- Anti-Toxins
What are the cardinal signs of inflammation?
- Heat
- Redness
- Swelling
- Pain
- Loss of function
What is the innate cellular response when cells are damaged?
- Damaged cells release chemotactic factors and cytokines
- Blood vessels near the site of injury dilate and become leaky
- Phagocytic cells such as macrophages and neutrofils are attracted to the site of injury and experience chemotaxis
- Heat, redness, and inflammation occur
- The inflammatory cells release more cytokines
What does chemotactic mean?
Chemicals that attract
What is chemotaxis?
Movement in response to a chemical stimulus
What are cytokines?
Chemical messengers between cells; how cells talk to each other
Where do viruses replicate?
Only inside cells
______ are polypeptides that are produced and secreted by cells containing viruses which help to prevent the spread of the virus by protecting other cells. They are a special type of cytokine.
Interferons
__________ are a type of lymphocyte that can recognize and destroy cells that are infected by viruses. They are part of the innate and acquired immune response.
Natural Killer (NK) cells
What two things are part of the immune response for viruses?
- Interferons
2. NK cells