AN SCI 320 FINAL

A state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity.

Health

A condition of a living animal or plant body or one of its parts that impairs normal function, typically manifested by distinguishing signs and symptoms.

Disease

A person's subjective experience of their symptoms, what the patient brings to their health care provider.

Illness

A social and cultural conception of a condition, influenced by cultural beliefs and reactions such as fear or rejection.

Sickness

A philosophical approach defining health and disease based on a natural class of organisms and normal function within that class.

Naturalism

Defines disease as deviancy from a more desirable state of affairs, reflecting values in the use of health and disease terms.

Normativism

Condition is a disorder if it causes harm judged by cultural standards and results in the inability of internal mechanisms to perform their natural function.

Hybrid Theories

Presence of resident microbes in contact with the body, essential for health and not causing disease under normal circumstances.

Colonization

Microorganisms residing in specific body sites without causing disease, essential for health by preventing infections and enhancing immune defenses.

Normal Flora

Condition where an infectious agent penetrates host defenses, leading to damage or disruption of tissues and organs.

Infection

Objective evidence of a disease that can be detected or measured by someone else.

Signs

Subjective evidence of a disease that must be described by the individual suffering from it.

Symptoms

The complete set of signs and symptoms associated with a specific disease.

Syndrome

The study and analysis of patterns, causes, and effects of disease and health-related factors in populations, essential for public health decision-making.

Epidemiology

the total number or proportion of cases or events or conditions in a given population

Prevalence

the number of new cases during a specified time period

Incidence

number of people affected with certain diseases during a given period of time

Morbidity rate

number of deaths in a population due to a certain disease during a given period of time

Mortality rate

the percentage of people with a specific disease that dies from that disease

Case-fatality rate

number of people affected by a disease divided by the number of people with a specific exposure

Attack rate

a relatively steady frequency over a long period of time in a particular geographic locale

Endemic

when occasional cases are reported at irregular intervals

Sporadic

increasing prevalence of a disease beyond what is expected

Epidemic

epidemic across countries and continents

Pandemic

the average number of new infections generated by one infection in a completely susceptible population

Basic Reproductive Number (R0)

estimates the average number of secondary cases per infectious case in a population made up of both susceptible and non-susceptible hosts

Effective Reproductive Number (R)

the time between the same stage of illness in successive clinical cases in a chain of transmissions

Serial Interval

the theory that microorganisms can cause diseases

Germ Theory

different shapes of bacteria including Coccus, Coccobacillus, Bacillus, Cocobacillus, Vibrio, and Spiral

Bacterial Shapes

components like Flagella, Pili/Fimbriae, and Bacterial Cell Wall Structure

Bacterial Cell Structure

a technique to differentiate bacteria into Gram-positive and Gram-negative based on cell wall properties

Gram Staining

the process of bacterial cell division

Bacterial Reproduction

a survival mechanism of certain bacteria under stressful conditions

Bacterial Endospore Formation

True pathogen and Opportunistic pathogen

Types of Bacterial Pathogen

the process of bacteria binding to host cells or tissues

Bacterial Adhesion

penetration of host cells and tissues by bacteria

Bacterial Invasion

production of toxins by bacteria

Bacterial Toxigenicity

factors that contribute to the pathogenicity of bacteria

Virulence Factors

highly structured microbial communities enmeshed in a self-produced slime matrix

Biofilm

The process by which bacteria adhere to surfaces and secrete a matrix to form a protective community.

Biofilm Formation

The ability of bacteria to resist the effects of antibiotics or toxins.

Antimicrobial Resistance

Categorization of viruses based on nucleic acid type, capsid symmetry, envelope presence, and virion dimensions.

Viral Classification

The process by which viruses replicate within host cells, including uncoating, transcription, protein synthesis, and assembly.

Viral Replication

The stages of reproduction and development in protozoa, involving asexual and sexual reproduction methods.

Protozoan Life Cycles

The active, feeding stage of most protozoa associated with pathogenesis.

Trophozoite

The process where some protozoa encase themselves in a protective wall for survival and transmission.

Cyst Formation

Various ways protozoa spread, including direct contact, fecal-oral route, vector-borne, and predator-prey transmission.

Mode of Transmission

Strategies used by parasites to evade immune detection, such as antigenic masking and intracellular location.

Protozoan Escape Mechanisms

The mechanisms through which protozoa cause damage to cells, tissues, and organs, leading to disease manifestations.

Protozoan Pathogenesis

Condition where the host's immune system is weakened, making them susceptible to secondary infections by other pathogens.

Immunosuppression

A parasitic protozoan that can cause infections in immunocompromised individuals, pregnant women, and fetuses.

Toxoplasma Gondii

Diseases of warm-blooded animals caused by fungi.

Mycoses

Eukaryotic organisms genetically more closely related to animals than plants, with about 1.5 million species, of which only 300 are pathogenic.

Fungal Pathogens

Includes Candida and Cryptococcus genera, causing diseases in humans and animals, with Candida being the most clinically relevant fungal group.

Yeast (Unicellular Fungi)

Diverse organisms found in soil and decaying vegetation, including Aspergillus and mucorales, causing rhino-sinusitis and pulmonary infections.

Molds (Multicellular Fungi)

Can exist as molds or yeasts, causing subacute pulmonary infections, and include pathogens like Blastomyces and Histoplasma.

Dimorphic Fungi

Nocardia and actinomycetes, originally thought to be fungi, causing subacute and chronic infections in immunocompromised individuals.

Bacteria which Masquerade as Fungi

Include the use of antibiotics, immunosuppressive drugs, cancer chemotherapy, corticosteroids, and environmental factors like warm, moist areas.

Risk Factors for developing fungal infections

Include superficial and cutaneous mycoses, mucocutaneous mycoses, subcutaneous mycoses, and systemic (deep) mycoses, each with distinct clinical presentations and treatments.

Classifications of Fungal Infections

Transmissible spongiform encephalopathies caused by infectious prions, leading to fatal neurodegenerative conditions.

Prion Diseases (TSEs)

Refers to the life cycle of Enterobius Vermicularis (pinworm) with a direct transmission route.

Simple (direct) Life Cycle

Involves multiple hosts in the life cycle, such as Paragonium westermani (Lung Fluke) and Fasciola Hepatica (Liver Fluke).

Complex Life Cycle

A prion disease identified in Papua New Guinea, characterized by neurodegeneration, initially linked to endocannibalism.

Kuru

Commonly known as Mad Cow Disease, a fatal neurodegenerative disease affecting cattle.

Bovine Spongiform Encephalopathy (BSE)

Proteinaceous infectious particles causing TSEs, resistant to degradation, leading to brain damage and fatal outcomes.

Prions

Study of the body's defense against infections, including innate and adaptive immune responses.

Immunology

Components that protect mucosal surfaces, prevent infections, and maintain immune balance in the gut.

Mucosal Immune System

Germline-encoded receptors recognizing microbial patterns, triggering immune responses.

Pattern Recognition Receptors (PRRs)

Rapid, nonspecific defense mechanisms against pathogens, involving cells like neutrophils, eosinophils, and macrophages.

Innate Immunity

Ability to move in response to chemical signals

Chemotactic capability

"Professional" antigen presenting cells that present antigens to T and B cells

Dendritic Cell

Recognize elements of most pathogenic microbes and initiate antimicrobial responses

Toll Like Receptors

Intracellular receptors that detect bacterial peptidoglycan and activate inflammatory responses

NOD Like Receptors

Intracellular receptors involved in viral recognition and defense mechanisms

RIG-I and MDA-5

Series of plasma proteins that amplify antimicrobial responses

Complement System

Cytokine-induced changes in protein synthesis during infection

Acute phase response

Proteins that interfere with viral replication and stimulate immune responses

Interferon

Present peptides to CD8+ T cells for killing virus-infected cells

MHC Class I Molecules

Present antigens to CD4+ T cells to activate macrophages and B cells

MHC Class II Molecules

The ability of the immune system to recognize and tolerate self-antigens to prevent autoimmunity.

Immune Tolerance

The process by which T cells are stimulated by antigen-presenting cells (APCs) to proliferate and differentiate.

T Cell Activation

The maturation process of B cells from fetal liver or bone marrow to become functional immune cells.

B Cell Development

Different types of immunoglobulins (Ig) such as IgG, IgM, IgA, IgD, and IgE, each with unique functions and properties.

Antibody Classes

The process by which B cells recognize antigens, undergo clonal expansion, and differentiate into plasma cells to produce antibodies.

B Cell Activation

The transfer of antibodies from mother to offspring via placenta, colostrum, or breast milk to provide temporary protection.

Maternal Transfer of Immunity

The administration of vaccines to induce an immune response and establish immune memory against specific pathogens for disease prevention.

Vaccination

The process by which B cells change the class of antibodies they produce, influenced by T helper cells to tailor immune responses.

Class Switching

The distinction between the initial immune response to an antigen (primary)

the stronger, faster response upon re-exposure (secondary).

Primary vs Secondary Immune Response

Additional vaccine doses given after the primary vaccination to enhance immune memory and maintain protective antibody levels.

Boosting

Individual:Focuses on decreasing severity of clinical signs after exposure, limiting pathogen replication/spread, preventing mortality, increasing infectious dose needed for illness, and reducing shedding.

Goals of Vaccination

Population Level:Aims to establish herd immunity by protecting unvaccinated individuals through immunizing a critical portion of the population.

Goals of Vaccination

Vaccines containing weakened pathogens that replicate in the recipient, stimulating both humoral and cellular immunity.

Attenuated Whole-Agent Vaccines

Vaccines with pathogens unable to replicate, primarily stimulating humoral immunity, and often requiring booster doses for adequate immunity.

Inactivated Whole-Agent Vaccines

Vaccines breaking viruses into components, expressing purified proteins to stimulate antibody production, lacking viral genomes, and being expensive.

Subunit Vaccines

Non-specific immune system stimulators enhancing vaccine response through depot, surface, and inflammation effects.

Adjuvants

Complete elimination of all organisms and viruses by chemical or physical means.

Sterilization

Chemical agent applied to inanimate objects to kill most pathogenic microbes, not effective against bacterial spores.

Disinfectant

Antibiotics inhibiting bacterial growth, reversible at low concentrations, and examples include sulfonamides and tetracyclines.

Bacteriostatic

Antibiotic discovered by Alexander Fleming, disrupting bacterial cell wall synthesis by interfering with linking enzymes.

Penicillin

The lowest concentration of a drug that inhibits the growth of a pathogen.

Minimal Inhibitory Concentration (MIC)