Chapter 16 study guide Flashcards
(44 cards)
The field of _____ concerns the geographical distribution and timing of infectious disease occurrences and
how they are transmitted and maintained in nature, with the goal of recognizing and controlling outbreaks.
epidemiology
The state of being diseased is called
morbidity
The_______ can be expressed as the number of diseased individuals out of a standard number of individuals
in the population, such as 100,000, or as a percent of the population.
morbidity rate
A _____rate can be expressed as the percentage of the population that has died from a disease or as the number of deaths
per 100,000 persons (or other suitable standard number).
mortality
is the number, or proportion, of individuals with a particular illness in a given population at a point in
time.
prevalence
is the number or proportion of new cases in a period of time.
incidence
diseases that are seen only occasionally, and usually without geographic concentration, are called ?
ex. tetanus, rabies, and plague
sporadic diseases
Diseases that are constantly present (often at a low level) in a population within a particular geographic region are
called
ex. malaria
endemic disease
Diseases for which a larger than expected number of cases occurs in a short time within a geographic region are
called
ex. influenza
epidemic
An ______ that occurs on a worldwide scale is called a pandemic disease
ex. HIV/AIDS and novel influenzas virus
pandemic
The main national public health agency in the United States is __________, an agency of the Department of Health and Human Services.
CDC
was a British physician known as the father of epidemiology for determining the source of
the 1854 Broad Street cholera epidemic in London.
Jon Snow
In an _______, data are gathered from study participants through measurements (such as physiological
variables like white blood cell count), or answers to questions in interviews (such as recent travel or exercise
frequency).
observational study
_________ gather data from the past on present-day cases. Data can include things like the medical
history, age, gender, or occupational history of the affected individuals.
retrospective studies
are typically retrospective and compare a group of individuals with a disease to a similar
group of individuals without the disease.
case control studies
follow individuals and monitor their disease state during the course of the study. Data on the
characteristics of the study subjects and their environments are gathered at the beginning and during the study so
that subjects who become ill may be compared with those who do not.
prospective studies
involve manipulation of subjects, they are typically more difficult and sometimes impossible
for ethical reasons.
experimental studies
can be living organisms or nonliving sites. Nonliving reservoirs can include soil and water in the environment. These
may naturally harbor the organism because it may grow in that environment. These environments may also become
contaminated with pathogens in human feces, pathogens shed by intermediate hosts, or pathogens contained in the
remains of intermediate hosts.
reservoirs
For pathogens to persist over long periods of time they require ____ where they normally reside.
reservoirs
A ____ is contaminated with the pathogen and can mechanically transmit it to another host; however, a passive
carrier is not infected.
passive carrier
For example, a health-care professional who fails to wash his hands after seeing a patient
harboring an infectious agent could become a passive carrier, transmitting the pathogen to another patient who
becomes infected.
passive carrier
is an infected individual who can transmit the disease to others
active carrier
For example, _______ may transmit the disease during the
incubation period (before they show signs and symptoms) or the period of convalescence (after symptoms have
subsided).
active carriers
Active carriers who do not present signs or symptoms of disease despite infection are called
asymptomatic carriers
