Introduction to Epidemiology and Pathogenesis - Vocabulary Flashcards

Vocabulary flashcards covering key epidemiology and pathogenesis terms from the lecture notes.

Sporadic

A single case of infectious disease or a collection of cases unrelated in time to other episodes of the same disease.

Endemic

Habitual presence or constant frequency (baseline) of a disease within a given geographical area.

Epidemic

The occurrence of an infectious disease in a community or region that is clearly in excess of the normal expectancy (statistics).

Pandemic

The spread of an infectious disease throughout continents.

Morbidity

The frequency of sickness of a specific disease in a population.

Mortality

The frequency of deaths in a population; death rate.

R0 (R-naught)

An indicator of how contagious a disease is in a population; on average, how many people one infected person can infect in a population where all persons are susceptible to infection.

Reservoir

Source of an infectious agent where the pathogen normally resides (humans, animals, or the environment).

Direct Transmission

Immediate transfer of infectious agent from reservoir to host without an intervening intermediary.

Vehicle

Nonliving material capable of transmitting a virus or other pathogen (e.g., water, air, fomites).

Infection

Colonization with successful replication and proliferation of the microorganism within the host tissues.

Pathogenesis

The sequence of events during the development of clinical disease, including how cells and tissues are injured.

Virulence

The degree of pathogenicity; how strongly a pathogen can cause disease (virulent vs avirulent).

Virulence Factors

Genetic and host-related elements that contribute to a pathogen’s ability to cause disease (e.g., virulence genes, host susceptibility, route of infection, dose).

Pathogenicity

The overall ability of a microbe to cause disease; encompasses virulence and other factors.

Koch’s Postulates

A set of criteria to establish etiology: the microorganism is found in diseased but not healthy individuals, can be cultured, causes disease in a susceptible animal, and can be re-isolated from the animal.

Tropism

Preference of a pathogen for specific cell types, tissues, or organs; determines target organ localization.

Congenital vs Neonatal Infections

Congenital: acquired in utero (transplacental); Neonatal: acquired at birth or shortly after.

Emergence Factors

Factors contributing to emergence of infectious diseases: social behavior changes, population growth, travel, mutation, and climate change.

Stages of Pathogenesis

Entry into the host, dissemination, localization to target tissues, interaction with the immune response, and tissue injury leading to disease.

factors that affect emergence of infectious agent

social behaviourpopulation growth mutation climate change

kochs postulates

A series of criteria used to establish a causal relationship between a microbe and a disease, including isolation of the microbe, cultivation, inoculation into a healthy host, and recovery of the microbe.