Infection Flashcards
Allergy’s
- Exaggerated response against noninfectious environmental substances
Hypersensitivity Reactions
- Inappropriate responses by the immune system
AutoImmunity
- Misdirected response against the body’s own cells
Alloimmunity
- Misdirected response against beneficial foreign tissues, such as transfusions or transplants
Factors Influencing Infection
-Communicability
- Ability to spread from one individual to another and cause disease
Ex. Measles and Pertussis spread very easily
-HIV has lower communicability
Factors Influencing Infection
-Immunogenicity
- Ability of pathogens to induce an immune response
Factors Influencing Infection
-Infectivity
- Ability of the pathogen to invade and multiply in host
Factors Influencing Infection
-Mechanism of Action
- Manner in which the microorganism damages tissues
Factors Influencing Infection
-Pathogenicity
- Ability of an agent to produce disease – depends on all of the above mentioned:
- communicability
- immunogenicity
- infectivity
- mechanism of action
Factors Influencing Infection
-Portal of Entry
- Route by which a pathogenic microorganism infects the host
- Direct Contact
- Inhalation
- Ingestion
- Insect “bites”
Factors Influencing Infection
-Toxigenicity
- Ability to produce soluble toxins or endotoxins
- factors that greatly influence virulence
Factors Influencing Infection
-Virulence
- Capacity of pathogen to cause severe disease
Classes of Infectious Microorganisms
- Bacteria
- Viruses
- Fungi
- Parasites
Pathogens Defense Mechanisms
-All Defenses
- Prevents Phagocytosis
- Changes surface antigens
- Hides
- Fast proliferation
- Produce Toxins
Pathogens Defense Mechanisms
-Changes surface antigens
- Adds surface antigens or causes major changes to surface antigens (antigenic Drift/Shift)
Antigenic Shift
- A major change in the genetic makeup of an organism, usually resulting from gene reassortment or occurring when different species share genetic material.
Ex. Influenza Virus Type A is the most common example of an organism that undergoes antigenic shift
Antigenic Drift
- A minor change in the protein marker or antigen on an organism.
- Ex. Influenza virus change from year to year
- Vaccinations against the virus have to be adapted annually to combat changes
Pathogens Defense Mechanisms
-Hides
- The pathogen hides inside the cell
Pathogens Defense Mechanisms
-Fast Proliferation
- Quickly multiplies to surpass the development of the protective response
Pathogens Defense Mechanisms
-Produce Toxins
- Produces toxins that destroy neutrophils
Pathogens Defense Mechanisms
-Prevent Phagocytosis
- Produce thick capsules of protein and carbohydrates to prevent phagocytosis
Pathogen
-Site of Entry
- Skin and mucous membrane
- Alimentary, GU and Respiratory Tracts
- Eyes and ears
Pathogen
-Route of Entry
- Direct Contact
- Inhalation
- Ingestion
- Vector bite
Pathogen
-Mechanism of Infection
- Adhesion
- Enzyme release
- Phagocytic escape
- Acid resistance
Pathogen for Each Entry Point
-Skin
- Chickenpox
Pathogen Entry Points
-Lungs
- Measles
2. TB
Pathogen Entry Points
-GU
- Gonorrhea
- AIDS
- Hepatitis B
- Yellow Fever
Infection
- Bacterial/Viral
- Clinical Manifestations
- Fever
- Body aches
- Lymph node enlargement