14B Principles of Disease and Epidemiology - Reservoirs and Transmission

This set of vocabulary flashcards covers principles of disease transmission, reservoirs of infection, nosocomial infections, emerging diseases, and the fundamentals of epidemiology as presented in the lecture notes.

Reservoir of infection

Continual sources of infection in the environment.

Carriers

Human reservoirs that may have inapparent infections or latent diseases, such as Typhoid Mary.

Zoonoses

Diseases that occur primarily in wild and domestic animals and can be transmitted to humans.

Nonliving Reservoirs

Environmental sources of infection, primarily soil, food, and water, which can harbor pathogens like Botulism and Tetanus.

Direct Contact Transmission

A mode of disease transmission that requires close association between an infected host and a susceptible host.

Droplet Transmission

Transmission of disease via airborne droplets that travel less than $1\,\text{meter}$, typically involving particles greater than $5\,\mu\text{m}$ in diameter.

Indirect Contact Transmission

The spread of a pathogen by nonliving objects called fomites.

Fomite

A nonliving object, such as a tissue, towel, or needle, that can transmit an infectious agent from a reservoir to a host.

Airborne Transmission

The spread of infectious agents by droplet nuclei (particles smaller than $5\,\mu\text{m}$) that travel more than $1\,\text{meter}$ from the source.

Horizontal Transmission

The direct transmission of a virus from host to host, not associated with the infection of offspring during pregnancy.

Vertical Transmission

The transmission of a virus from one generation to the next through congenital infection.

Vehicle Transmission

The transmission of disease by an inanimate reservoir such as food, water, or dust.

Vectors

Arthropods, specifically fleas, ticks, and mosquitoes, that carry pathogens from one host to another.

Mechanical Transmission

The passive transport of pathogens on an insect's feet or other body parts.

Biological Transmission

An active process in which a pathogen reproduces within a vector before being transmitted to another host.

Nosocomial Infections

Infections acquired specifically as a result of a hospital stay, affecting $5-15\%$ of all hospital patients.

Compromised Host

An individual whose resistance to infection is impaired by disease, therapy, or burns.

MRSA

Methicillin-Resistant Staphylococcus aureus, a major cause of nosocomial infections emerging in the early 1990s.

VRSA

Vancomycin-resistant Staphylococcus aureus, a highly resistant strain first identified in 2002.

Emerging Infectious Diseases (EIDs)

Diseases that are new, increasing in incidence, or showing a potential to increase in the near future.

Epidemiology

The science that studies where and when diseases occur and how they are transmitted in populations.

Descriptive Epidemiology

A type of epidemiology involving the collection and analysis of data regarding the occurrence of disease, often retrospective as practiced by John Snow.

Analytical Epidemiology

The comparison of a diseased group and a healthy group to determine the cause of a disease, pioneered by Florence Nightingale.

Case Control Method

An analytical epidemiological approach that compares a group with a disease against a group without it.

Cohort Method

An analytical epidemiological approach that compares a group with a specific exposure against a group without that exposure.

Experimental Epidemiology

The study of a disease using controlled experiments, such as those conducted by Semmelweis.

Nationally Notifiable Diseases

A list of specific diseases that clinicians are required by law to report to local, state, and national health offices.

CDC

Centers for Disease Control and Prevention; the U.S. agency that collects and analyzes epidemiological info and publishes the MMWR.

Morbidity

The incidence or number of cases of a specific notifiable disease.

Mortality

The number of deaths resulting from notifiable diseases.

Morbidity Rate

$$\frac{\text{number of people affected}}{\text{total population in a given time period}}$$

Mortality Rate

$$\frac{\text{number of deaths from a disease}}{\text{total population in a given time period}}$$

WHO

World Health Organization; a specialized agency of the United Nations responsible for international public health and global health standards.