Principles of Disease and Epidemiology

A comprehensive set of flashcards covering key concepts in pathology, infection, disease, and epidemiology.

Pathology

The study of disease caused by pathogens and the relationship between pathogen and host.

Etiology

The study of the cause (origin) of a disease; the causative agent responsible for the disease.

Pathogenesis

The development of disease, involving structural and functional changes in the host.

Infection

Invasion or colonization of the body by pathogens, which can lead to disease.

Infectious disease

A disease caused by pathogens.

Non-infectious disease

A disease not caused by pathogens, such as diabetes and cancer.

Resident microbiota

Microorganisms that are always present in and on the human host.

Transient microbiota

Microorganisms that occupy the body temporarily; they can be removed by washing or bathing.

Symbiosis

The relationship between a microbe and the host, indicating who benefits.

Commensalism

A relationship where one organism benefits and the other is unaffected.

Mutualism

A relationship where both organisms benefit from each other.

Parasitism

A relationship where one organism benefits at the expense of the other.

Koch’s Postulates

A series of criteria to establish a causative relationship between a microbe and a disease.

Incidence

The number of new cases of a disease that develop in a specific time period.

Prevalence

The total number of cases of a disease at a given time.

Sporadic disease

A disease that occurs occasionally with no predictable pattern.

Endemic disease

A disease that is constantly present in a population.

Epidemic disease

A disease that affects a large number of people in a short period.

Pandemic disease

A global outbreak of a disease.

Acute disease

A disease with rapid onset but short duration.

Chronic disease

A disease that develops slowly and lasts for a long time.

Latent disease

A disease where the causative agent is inactive for a time but can reactivate.

Herd immunity

Protection of an entire population through vaccinations.

Local infection

An infection limited to a small area of the body.

Systemic infection

An infection that spreads throughout the body.

Primary infection

The initial infection that causes illness.

Secondary infection

Infection caused by opportunistic pathogens following a primary infection.

Predisposing factors

Factors that increase susceptibility to disease.

Incubation period

The time interval between initial infection and the first signs and symptoms.

Prodromal period

The initial phase of mild symptoms following the incubation period.

Period of illness

The phase where severe signs and symptoms are present.

Period of decline

The phase where signs and symptoms are decreasing.

Convalescence

The recovery period where the body returns to its pre-disease state.

Reservoir of infection

The continual source of infection, where pathogens reside.

Human reservoirs

Humans that harbor pathogens, including carriers with no symptoms.

Animal reservoirs

Pathogens that are usually found in animals, which can transmit to humans.

Non-living reservoirs

Pathogens found in contaminated inanimate objects like soil and water.