ENC 1101 Definition-Concept Essay The purpose of this essay .docx

ENC 1101 Definition-Concept Essay
The purpose of this essay is to give you the opportunity to
develop a viewpoint on a word and its representation within a
particular context or situation. First, you will closely observe
different representations of the word and consider several
viewpoints and perspectives. After considering those various
perspectives, you will develop and articulate your own unique
interpretation and definition of a word, and then support your
definition with explanation, description, and research.
Characteristics of the Definition Essay
A successful essay
provides an engaging introduction of the example to prepare the
context for the word itself with respect to your audience
narrows the definition of the word by providing a specific thesis
at the end of your introduction
makes use of description and examples through close
observation in supporting paragraphs to support the thesis
includes specific details and evidence from secondary sources
creates an objective stance by the use of third-person voice
integrates quotations from secondary sources
conforms to MLA guidelines for source documentation and
format.
Topic: Please define one of the below terms:
Beauty
Courage
Femininity
Friendship
Greed
Happiness
Leadership

Love
Masculinity
Patriotic
Smart
Successful
As you define your selected term, consider the following
questions:
What is an appropriate definition of the term?
What are characteristics society often associates with the term?
Is there a characteristic you think should not be associated with
the term?
How does the media (e.g., television, movies, news, social
media, etc.) often portray the “term”?
Are there positive connotations of the term?
Are there any negative connotations of the term?
Is the term defined differently in other cultures?
Should society rethink the use of the term?
Is the term overused?
Are there instances in which another term should be used to
articulate a point?
As you write your essay, do not try to answer all of the
questions in your essay. I suggest that you consider these
questions as you define your term (concept).
Length of Paper: at least 3 pages
Important Reminders
Do not write a personal narrative about yourself or someone you
know. The focus of this essay should be on the term, concepts,
and characteristics.
Reference and cite at least three secondary sources in your
essay. One of your sources should come from the TCC database.
You may reference and cite a dictionary, but you should count a
dictionary as a fourth source. Also, do not cite Wikipedia as a

source.
Do not write in second person (e.g., you, your, yourself, or
imperative sentence).
MAKE SURE YOUR PAPER HAS A TITLE. YOUR TITLE IS
NOT THE REWORDING OF THE PROMPT. YOUR TITLE
SHOULD REFLECT YOUR THESIS, OR THE PREMISE OF
YOUR ESSAY!!!!!!!
Submission:
Please do not email your final papers!
Please remember to attach all rough drafts with your
submissions.
Please remember to save an electronic version of the paper to
your TCC drive.
Other reminders: Font Times Roman / Size 12; Double Spaced;
Include Page Numbers (top right corner of page); and NO
COVER PAGE. Your first page should look like this:
(Insert Page Number Using the Word Program) Doe 1
(Top left, Single Space; some teachers might ask you to place it
on top right and double space)
Jane Doe (Your name)
ENC 1101.Reference # (the class and the reference)
K. Thompkins (my name)
November 28, 2018 (Date the paper is due)
If You Want to Feel Funky, Feel Free. But Please Don’t Spread
that Funk on Me: Social Commentary in Today’s Comedy
Routines (Sample Title)
Introduction (Length for this essay: 1-2 paragraphs)
Provides background information about the topic
Defines any key terms

Establishes a context for the paper
Includes a thesis statement
Body of essay (Length for this class: 3-4 paragraphs)
Develops the thesis by discussing main points
Introduces the first main point with a topic sentence
Provides supporting details and examples
Engages / Explores the topic
Possible Organizational Pattern:
Identify characteristic (Topic sentence)
Define characteristic
Discuss characteristic in terms of its importance to being a hero
Cite examples of people who or professions that exhibit these
heroic characteristic
Close reiterating the importance of the characteristic to being a
hero
Transition to the next paragraph
Conclusion (Length for this class: 1-2 paragraphs
Summarizes the discussion
Asks the reader to consider other ways of approaching the topic
for future exploration
Brings closure to the topic
Works Cited
If you have any other questions, please see me during my office
hours, or email me.
Thank You! And Happy Drafting!!!
6 Epidemiology

Microgen/iStock/Thinkstock
Learning Outcomes
After reading this chapter, you should be able to
• Explain epidemiology and its use in public health.
• Outline methods for disease surveillance.
• Compare descriptive and analytic epidemiology.
• Apply the 13 epidemiological steps to investigations.
© 2019 Bridgepoint Education, Inc. All rights reserved. Not for
resale or redistribution.
182
Section 6.1 What Is Epidemiology?
Understanding how, when, and why disease occurs is crucial for
successful public health ini-
tiatives. This chapter will demonstrate how studying the
incidence, distribution, and control
of disease contributes to the field of community health.
Epidemiology is important because
many circumstances that produce adverse health effects among
community residents occur
at the population level; thus, it is vital to take a population
perspective when examining indi-
vidual health outcomes in the community. For example, people
in communities surrounded

by high traffic volume are likely to suffer from respiratory
issues because of the exhaust par-
ticles in the air. A city susceptible to frequent cloud cover and
very few sunny days, such as
Seattle, Washington, might struggle more with mental
health/depression. The study of how,
when, and why disease occurs focuses on the health of
populations, and, in this respect, it dif-
fers from clinical medicine’s involvement with individual
patients.
In fact, epidemiology provides a method-
ological foundation for the entire public
health field by embracing a spectrum of
tools for studying health and illness. These
methodologies include natural experiments,
descriptive and analytic study designs (e.g.,
cross-sectional, case-control, cohort, and
experimental), and mapping technologies.
Epidemiologic research findings help develop
hypotheses that can be applied to the health
of the community and the study of potential
causal relationships.
Epidemiologic research is likened to detective
work because the causes of many diseases—
especially when they first appear—are
unknown. Some examples are hantavirus in national parks,
periodic episodes of foodborne
illnesses, West Nile virus, and the resurgence of whooping
cough (pertussis). This chapter
presents epidemiologic procedures and methodologies that aid
in unraveling the causes of
mysterious disease outbreaks and health conditions that can
afflict community members.

6.1 What Is Epidemiology?
Epidemiology is the study of the occurrence and distribution of
illnesses, injuries, and dis-
eases in specific populations. It also includes the study of the
factors that influence illnesses,
diseases, and injuries in an effort to help reduce or eliminate the
problem.
Epidemiology is a discipline that describes, quantifies, and
finds possible causes, or deter-
minants, for health phenomena in populations. Determinants are
also known as etiological,
or causal, factors. Recall that a determinant of health is a factor
that affects health either
negatively or positively. For example, economic status is
considered a determinant. Those
with more money seem to have better health outcomes than
those with less money, making
income also a determinant of health. Other examples of
determinants or etiological factors
are behavioral, such as smoking (negative) or physical activity
(positive). Smoking is a factor
in the development of arteriosclerosis, which is a poor health
outcome. Physical activity can
ward off obesity and obesity-related diseases, which is a good
health outcome.
PBFloyd/iStock/Thinkstock
Epidemiologists study the how, when,
and why of a disease outbreak by using
different methods of investigation, including
experiments and mapping.

183
The results of epidemiologic studies aid public health
practitioners in their quest to control
health problems such as disease outbreaks. Like much of public
health, epidemiology is inter-
disciplinary because it operates within other fields, including
clinical medicine, biostatistics,
toxicology, the social sciences, and genetics. One example of
this interdisciplinary approach
is the application of genetics and the Human
Genome Project to epidemiology in order to con-
duct research on the genetic bases for breast and
ovarian cancer. The Human Genome Project began
in 1990 as an international effort to understand the
sequence of chemicals in DNA and to identify and
map the thousands of genes in the human genome.
Researchers delivered a complete map in 2003,
propelling further genomic research and explora-
tion into medical applications. Epidemiologists are
using that information to uncover the link between
genes and certain cancers, such as breast cancer.
History
The history of epidemiology extends over many centuries,
beginning with the contributions
of the ancient Greeks during the classical period. Some of the
landmarks in the history of epi-
demiology overlap with the history of public health. Recall the
historically noteworthy and
frightening epidemics that threatened the very existence of

humanity, which were detailed
in Chapter 1. These epidemics included the Black Death, which
occurred between 1346 and
1352, and the great influenza pandemic that coincided with
World War I early in the 20th
century. Significant historical developments in epidemiology
included Edward Jenner’s devel-
opment of an effective vaccine against smallpox, and Robert
Koch’s work that led to the iden-
tification of microbial agents in human disease. In 1928,
Alexander Fleming discovered that
certain molds had antibiotic properties. As a result of this
research, the antibiotic penicillin
became available at the end of World War II. Table 6.1 lists
several other important mile-
stones in the history of epidemiology.
Jupiterimages/Stockbyte/Thinkstock
Physical activity is an example of a
determinant or etiological factor that
can positively affect one’s health.
Table 6.1: Key events in the history of epidemiology
Date Event Significance
400 BCE Hippocrates publishes On Airs, Waters, and
Places
Implies that the physical environment is
associated with human illness
1662 John Graunt publishes Natural and Political
Observations
Pioneers work in vital statistics (data that

pertain to births and deaths)
Mid-1800s John Snow investigates a cholera outbreak
in London
Uses the method of natural experiment to
examine the causes of cholera
1964 The surgeon general’s report Smoking and
Health is published
States that smoking is the cause of lung
cancer
1974 The Lalonde Report, A New Perspective on
the Health of Canadians, is published
Initiates large community health studies;
community interventions are implemented
184
Hippocrates Links Environment and Illness
In 400 BCE, the Greek physician Hippocrates suggested in his
treatise On Airs, Waters, and
Places that disease could be linked with a person’s physical
environment—marking perhaps
the earliest instance that logic, rather than mysticism, was used
to explain an illness’s origin

(Friis & Sellers, 2009). Hippocrates wrote that the seasons, the
influence of the sun, the qual-
ity of water, and the elevation at which people live were factors
in health.
John Graunt Describes Trends in Vital Statistics
In 1662, John Graunt published Natural and Political
Observations Mentioned in a Following
Index, and Made Upon the Bills of Mortality, more commonly
referred to as simply Observa-
tions. Graunt described various details of birth and death data,
including seasonal variations
and infant mortality. Public health historians regard Graunt’s
work as among the first to
organize mortality data in tables in order to discern trends in
births and deaths from spe-
cific causes (Friis & Sellers, 2009). Refer to Spotlight on Public
Health Figures for more about
Graunt’s contributions to public health.
Spotlight on Public Health Figures:
John Graunt (1620–1674)
Who is John Graunt?
John Graunt was born in 1620 to a storekeeper
in England. He was the oldest of eight children.
He initially worked as a shopkeeper like his
father but eventually became involved in
politics for the city of London. Despite his
lack of formal education, he found mortality
statistics interesting and wrote a book called
Natural and Political Observations Mentioned
in a Following Index, and Made Upon the Bills
of Mortality. In this book, Graunt analyzed
London’s “bills of mortality”—basically a list of
the dead—and was the first to use this kind of

data to identify trends and draw conclusions.
What was the political climate at
the time?
During Graunt’s adulthood, Britain was prospering. The
economy was strong, and trade and
colonization were extending across the globe. It was also
considered the age of intellectual
advances, and the time period produced a number of thinkers
such as poets John Milton and
John Dryden, philosophers such as John Locke and Thomas
Hobbes, and scientists such as
Isaac Newton and Robert Boyle.
(continued)
evryka23/iStock/Thinkstock
John Graunt was fascinated by
statistics. He wrote Observations,
which helped set up a framework for
tracking vital population statistics.
185
John Snow Maps Cholera Outbreak
Chapter 1 described the work of John Snow, who, during the
mid-19th century, investigated
a cholera epidemic in London, eventually linking the epidemic
to contaminated water sup-

plies (Snow, 1855). His classic observational study reflects
many of the features of modern
epidemiologic inquiry, including mapping the location of
instances of disease and tabulating
fatalities. The natural experiment described in Snow on Cholera
(Frost, 1936/1965), which
includes two papers by John Snow and a biographic memoir,
reported how changing to a
cleaner water source reduced the occurrence of cholera. Despite
the absence of knowledge
about the nature of microbial agents during his time, Snow
made numerous insightful discov-
eries that could be applied subsequently to the control of
epidemics.
Smoking and Lung Cancer Linked
The 1964 surgeon general’s report Smoking and Health stated
that cigarette smoking is a cause
of lung cancer in men (U.S. Department of Health and Human
Services, 1964). This report
caused a global reaction when it first appeared. The report listed
five “criteria of judgment”
John Graunt (1620–1674) (continued)
What was his contribution to public health?
Long before epidemiology was a science, the field of statistical
collection was known as
the science of demography. John Graunt is considered the
founder of this field, making him
the greatest demographer of his time. His Observations was the
first organized analysis of
vital statistics in London, which had been collected over a 70-
year period following the
Black Plague. Graunt soon realized that his research could be

used to make projections of
population figures. Graunt was the first to publish the fact that
more boys than girls are born
to a population, but the mortality rate for males is far greater.
This was the beginning of the
use of vital statistics in research and later in epidemiology and
public health.
What motivated him?
Because the political climate of the time in Britain was one of
intellectual advancement,
Graunt was strongly encouraged to pursue whatever field
interested him. He was fascinated
with statistics—in particular, the number of deaths from the
Great Plague, which ended
before his birth. It was his fascination with those deaths that
prompted him to keep a count
of them and other incidents of mortality around the nation.
Sources: John Graunt facts. (2010). In Encyclopedia of World
Biography. Retrieved from http://biography.yourdictionary.com
/john-graunt
Sommerville, J. P. (2018). Britain in the seventeenth century.
Retrieved from https://faculty.history.wisc.edu/sommerville/351
/england.htm
http://biography.yourdictionary.com/john-graunt
http://biography.yourdictionary.com/john-graunt
https://faculty.history.wisc.edu/sommerville/351/england.htm
https://faculty.history.wisc.edu/sommerville/351/england.htm
186

that were used to judge the statistical causal significance of the
association between smok-
ing and lung cancer. These criteria were strength of association,
time sequence, consistent
relationship upon repeated exposure to smoking, specificity of
association, and coherence of
explanation. The authors of the report said that accumulated
research conducted up to the
time of the report tended to support these five criteria of
judgment in testing causal associa-
tions between this health behavior and morbidity due to lung
cancer. Refer to Spotlight on
Public Health Figures for more about Luther Terry, the surgeon
general when the Smoking and
Health report was published.
Luther Terry (1911–1985)
Who is Luther Terry?
Luther Terry was born in 1911 in Alabama. He
earned a bachelor’s degree from Birmingham-
Southern College in 1931 and his medical degree
from Tulane University, Louisiana, in 1935. John
F. Kennedy appointed him U.S. surgeon general in
1961, and shortly after that, Terry made it his life
mission to end the nation’s smoking habit. He had
been a smoker himself, quitting in 1963. A year
later, he delivered a staggering health report on the
effects of smoking.
What was the political climate at
the time?

The 1960s were a time of political change and revolution. The
decade ushered in an era
of protest, including the civil rights movement, female activism,
and protests against the
war in Vietnam. The American political system was also shaken
when John F. Kennedy
was assassinated in 1963. There was a significant amount of
unrest. Terry’s tackling of the
smoking habit was nothing short of a miracle. Given the unrest
and changes occurring in the
nation, it was difficult for contemporary politicians to focus on
one particular issue. Terry’s
points about smoking made it through the noise and began an
era of reduced tobacco use.
What was his contribution to public health?
Terry was the first to conclusively determine that smoking
caused various diseases. Since his
report, smoking has been recognized as a risk factor for various
diseases, including illnesses
from secondhand smoke. Terry’s actions led to a number of
other reports on the dangers
of smoking. His efforts also spurred the development of the
Federal Cigarette Labeling and
Advertising Act of 1965, which required warning labels on
cigarettes, and the Public Health
Cigarette Smoking Act of 1969, which modified that label to
read, “Warning: Excessive
Cigarette Smoking Is Dangerous to Your Health,” in addition to
other terminology currently
seen on tobacco package labels. This was a major milestone, as
smoking was viewed and
advertised as glamorous at the time.
(continued)

Associated Press
Luther Terry was a surgeon
general. He devoted much of his
professional career to reducing
tobacco use among the population.
187
Levels of Disease
The history of epidemiology portrays the humble beginnings of
how humans have discovered
diseases and learned to identify and track those diseases. Public
health is so intertwined with
identifying, tracking, and stopping both infectious and chronic
diseases that epidemiology
has grown into its own field.
Epidemiologists use a variety of terms to refer to outbreaks. A
sporadic outbreak occurs
when diseases break out infrequently and irregularly, cluster
outbreaks are the constant
presence of a disease or infectious agent within a population,
and hyperendemic outbreaks
are a high level of disease occurrence (CDC, 2012a).
The following terms identify the levels to which disease can
spread:
• An epidemic is a widespread occurrence of a disease.

Typically, epidemics occur
when a disease-causing agent is present in adequate numbers to
cause illness or
disease across a large geographic area. A good example is
seasonal influenza in the
United States.
• A pandemic refers to an epidemic that has spread across
several countries or conti-
nents, affecting significant numbers of people. The Black Death
(bubonic plague of
the 15th century) was a pandemic.
• An endemic is the constant presence of a disease in a
population within a specific
geographic area. One example is the Ebola outbreak in West
Africa. The disease was
prevalent in West Africa, but not elsewhere in the world.
Luther Terry (1911–1985) (continued)
What motivated him?
His own battle with nicotine addiction was the most motivating
factor for Terry. After he quit,
he wanted to urge the rest of the nation’s smokers to do the
same. In his famous surgeon
general’s report Smoking and Health, he conclusively
determined that smoking caused
cardiovascular disease, emphysema, and lung cancer. He based
his conclusions on more than
7,000 peer-reviewed articles on the topic, asserting that they
provided more than sufficient
evidence to conclude smoking was the cause.
Sources: Campbell, S. L. (2018). Social climate of the 1960s in

America. Retrieved from https://classroom.synonym.com/social-
climate
-1960s-america-22162.html
Flannery, M. A. (2017). Luther Terry. Retrieved from
http://www.encyclopediaofalabama.org/article/h-1241
Society and life in the 1960s. (n.d.). In English Online.
Retrieved from http://www.english-
online.at/history/1960s/society-and-change
-in-the-sixties.htm
U.S. National Library of Medicine. (n.d.). The reports of the
surgeon general: The 1964 report on smoking and health.
Bethesda, MD:
Author. Retrieved from
https://profiles.nlm.nih.gov/ps/retrieve/Narrative/NN/p-nid/60
https://classroom.synonym.com/social-climate-1960s-america-
22162.html
https://classroom.synonym.com/social-climate-1960s-america-
22162.html
http://www.encyclopediaofalabama.org/article/h-1241
http://www.english-online.at/history/1960s/society-and-change-
in-the-sixties.htm
http://www.english-online.at/history/1960s/society-and-change-
in-the-sixties.htm
https://profiles.nlm.nih.gov/ps/retrieve/Narrative/NN/p-nid/60
188
Many current and historical examples of epidemics exist,
including recent epidemics of influ-

enza, whooping cough, and foodborne illnesses. In order to
monitor the presence of epidemic
disease, local and state public health departments and the CDC
have implemented surveil-
lance systems. These involve the periodic reporting of
conditions, known as reportable and
notifiable diseases, and compiling statistics on their occurrence.
When the incidence of a
reportable disease such as influenza exceeds statistical limits,
this event suggests that an epi-
demic is underway.
Epidemiological Measures
Public and community health epidemiologists as well as
researchers use measures of disease
occurrence for a variety of purposes. These include identifying
epidemics and other health
problems, assessing the effectiveness of prevention programs or
interventions, finding health
disparities, and showing associations between exposures and
health outcomes. Fundamental
measures discussed in this section are summarized in Table 6.2.
Table 6.2: Review of common epidemiologic measures
Measure Description
Count Total number of cases of the disease or other health
phenomenon being studied
Ratio The relationship between two comparable amounts
Proportion A type of ratio; may be expressed as a percentage,
indicating the part of a whole
Prevalence A measure of disease occurrence meaning the total

number of cases of disease
Point prevalence The frequency of disease or other condition at
a given point in time
Case fatality rate Number of deaths caused by disease among
those who have the disease during a
specified period
Incidence A count of new cases of disease among a group
within a specified period
Rate A measure that includes time as a part of the denominator
Incidence rate A disease’s rate of development within a group
during a specified period
Mortality rate The number of deaths during a given year divided
by the size of a reference
population (or denominator) during the middle of the year in
question
General Measures
The simplest and most commonly used quantitative measure in
epidemiology is a count,
which is the total number of cases of the disease or other health
phenomenon being studied.
One example could be the number of falls in a nursing home
during a 1-month period.
A ratio shows the relationship between two comparable
amounts. For example, a sex ratio
would compare the number of male cases to female cases. A
ratio can also be expressed as a
value, when the first quantity is divided by the second. For
example, the sex ratio of births in

the United States is greater than 1, indicating that more boys
than girls are born.
189
A proportion is a type of ratio and may be expressed as a
percentage, indicating the part of a
whole. For example, only a small proportion of graduates fails
to find employment.
Prevalence and Incidence
Two examples of more complex epidemiologic measures are
prevalence and incidence—two
terms that are often used incorrectly in the professional
literature. Prevalence is a measure
of disease occurrence, meaning the total number of cases of a
disease. Point prevalence is
the frequency of a disease or other condition at a given point in
time. For example, the preva-
lence of influenza or pertussis is the number of cases of that
disease in a population. Point
prevalence is a proportion. A point prevalence example would
be the number of influenza
cases reported on December 15, 2017. If there were 50 cases of
influenza reported on that
date and there were 1,000 total cases of influenza reported for
the winter of 2017–2018, the
point prevalence is 50/1,000 for December 15.

Incidence refers to a count of new cases of disease among a
group within a specified period.
An example of incidence is the number of new cases of
influenza that occur within a time
interval such as a 2-week period.
Rates
A rate is a measure that includes time as a part of the
denominator. It consists of a numerator
(the frequency of new cases of disease during a specified
period) and a denominator, which is
a unit size of population. The population could be of a
community, a state, or an entire country.
To calculate a rate, one must consider two points in
time: the beginning of the period and the end of the
period during which the new cases occur. Rates are
expressed as numbers per unit size of population
(e.g., 10 per 1,000 persons in a population or some
other number per unit size of population). Inci-
dence, for example, can be expressed as a rate. If 10
people in a given population get the flu in November
(which has 30 days), the incidence of flu is 10:30,
or 10 cases every 30 days, which is equal to 1 case
every 3 days. (Note that prevalence is never a rate.)
An incidence rate describes a disease’s rate of
development within a group during a specified
period. This rate uses only the frequency of new
cases that occur during a time period in the numer-
ator. Consequently, individuals who already have
the disease are not included in the numerator. The
denominator for incidence rates is the population
at risk: those who are capable of developing the
disease either because they are not immune or
for some other reason. An incidence rate includes

(1) a numerator—the number of new cases, (2) a
Karen Kasmauski/SuperStock
To determine the case fatality rate for
a disease, such as hantavirus, which
is thought to be spread by deer mice,
divide the number of infected patients
by the number of infected patient
deaths, and then multiply that number
by 100.
190
Section 6.2 Disease Surveillance
denominator—the population at risk, and (3) time—the period
during which the cases
amass. Again, imagine a population of 100 people. During
influenza season 2017–2018, 20
people from September through February get sick. In this case,
then, the rate of influenza for
that season was 20:100, or 1:5.
The mortality rate is the number of deaths during a given year
divided by the size of a refer-
ence population (or denominator) during the middle of the year
in question. For example,
if there is a community with 1,000 people and 10 died in 2017,
then the mortality rate was
10:1,000, or 1 in 100.

The case fatality rate refers to the number of deaths caused by a
disease among those who
have the disease during a specified period. To better understand
this concept, consider this
example: If 50 people became infected with hantavirus and 8 of
them died, the case fatality
rate would be (8 ÷ 50) × 100 = 16%.
6.2 Disease Surveillance
There are several data sources for tracking and monitoring
diseases across the United States.
These sources provide information on a variety of levels to help
monitor the health of the
nation. While there are numerous sources available for
epidemiology, this section will focus
on these key resources: the National Notifiable Diseases
Surveillance System, Vital Statistics
Reports, morbidity surveys, U.S. Census data, and case
registries.
The National Notifiable Diseases Surveillance System
By legal statute, physicians and other health care providers
must report cases of diseases
known as reportable and notifiable diseases. The reporting
individuals send the information
to local agencies such as health departments, from which it
flows to state and federal levels.
Notifiable disease reporting at the community level protects the
public’s health by ensuring
the proper identification and follow-up of cases of disease.
These diseases are usually infec-
tious and communicable ones that might endanger a population.
The reportable and notifi-
able diseases in the United States are the following:
• Anthrax

• Arboviral diseases
• Botulism
• Cholera
• Hepatitis
• Human immunodeficiency virus (HIV)
• Meningococcal disease
191
• Rabies
• Salmonellosis
• Tuberculosis
Reportable and notifiable disease reports contain official
statistics in tabular and graphical
form. Statistics are collected and compiled from reports sent by
state health departments and
U.S. territories to the National Notifiable Diseases Surveillance
System, which is operated by
the CDC in collaboration with the Council of State and
Territorial Epidemiologists.
Vital Statistics Reports
The types of information in this category include data collected
on vital events (births and
deaths) by the vital registration system of the United States.
Statistics derived from the vital
registration system are computed from the data that are
collected routinely on all births

and deaths that occur in the United States. For instance, birth
certificate data are needed
to calculate birth rates. In addition, this information may also
contain data about a range
of conditions that could affect newborn children, including
conditions present during preg-
nancy, congenital malformations, obstetric procedures, birth
weight, length of gestation, and
the demographic background of mothers. Death certificate data
in the United States include
demographic information about the deceased person and
information about the cause of
death, including the immediate cause and contributing factors
(Friis & Sellers, 2009).
Morbidity Surveys for the Population
Morbidity surveys are procedures for collecting information on
the health status of a pop-
ulation group by using self-administered questionnaires,
interviews, and direct examina-
tions of participants (Friis & Sellers, 2009). They are designed
to determine the frequency of
chronic and acute diseases and disability, to obtain
measurements of bodily characteristics, to
conduct physical examinations and laboratory tests, and to
probe other health-related char-
acteristics of special concern to those who sponsor the survey.
Two examples are the National
Health Interview Survey and the Behavioral Risk Factor
Surveillance System.
Conducted by the National Center for Health Statistics, the
National Health Interview Sur-
vey (NHIS) is a household health interview survey that has been
collecting data on a broad
range of health topics since 1957 (CDC, 2017q).

The Behavioral Risk Factor Surveillance System (BRFSS) is the
world’s largest ongoing
telephone health survey system. BRFSS began collecting
information on risk behaviors and
tracking health conditions in the United States in 1984 (CDC,
2017q). Results from the BRFSS
have provided data to track a community’s health status, access
to health care, and progress
toward achieving state and national health objectives.
192
U.S. Census Data
The Census Bureau is an invaluable resource for
characteristics of the United States population. Cen-
sus data provide information about the denomina-
tors used in the calculation of measures of morbid-
ity and mortality. Recall that a denominator is the
number of parts into which the whole is divided.
For example, it is important to know how many
people exist in a population to determine mortality
and incidence rates. If 10 people died of lung can-
cer in a city but the actual population of the city is
unknown, then that number doesn’t reveal much.
However, if 10 died of lung cancer in a population
of 1 million, then we know that the rate is 10:1 mil-
lion, which is relatively low. But, if the city under

review has 50 total residents, then 10 deaths out of 50 is
significant because 1 in 5 would
have died of lung cancer. That would raise a red flag for
epidemiologists to investigate such
a high rate of lung cancer.
The decennial (10-year) census counts every resident in the
country. Census 2010, the most
recent census to date, provides detailed information about the
country’s entire population,
including the variables of age, sex, race, and ethnicity, as well
as housing characteristics and
household information (United States Census Bureau, 2010).
Researchers can extract this
information from census data sets in order to describe the
sociodemographic and other char-
acteristics of a specific community.
Case Registries
A registry is a centralized database for collection of information
about a particular disease.
Registries are used commonly for the compilation of statistical
data on cancer, although other
types of disease registries exist. Two examples of population-
based registries include the
Sudden Unexpected Infant Death (SUID) Case Registry and the
Sudden Death in the Young
(SDY) Case Registry. Epidemiologists use census data
combined with registry data to deter-
mine significance. If a population of 100 reported 20 deaths to
the SUID registry, then the rate
is 20:100 or 1:5. However, if those 20 SUID reports came from
a population of 1.2 million, the
rate is 20:1,200,000 or 1:60,000, a rate that is not nearly as
significant as 1 in 5. The SUID
registry has 18 monitored sites across the United States (Figure

6.1).
jcamilobernal/iStock/Thinkstock
The United States Census occurs every
10 years. The census helps collect
valuable information about population
variables such as age, sex, and housing
characteristics.
193
Section 6.3 Descriptive and Analytic Epidemiology
6.3 Descriptive and Analytic Epidemiology
Epidemiology is divided into two categories. Descriptive
epidemiology uses descriptive stud-
ies or cases to describe the occurrence of disease, and analytic
epidemiology uses analytic
studies or cases to identify the causes of disease.
Descriptive Epidemiology
One of the most useful applications of epidemiology,
descriptive epidemiology is the char-
acterization of disease occurrence in populations according to
classifications by person,
place, and time variables. It identifies that something has
occurred among a specific group in
a specific location, but not necessarily how or why it occurred.
It has three broad objectives:
Figure 6.1: SUID Registry monitoring sites

The CDC routinely monitors sudden unexpected infant deaths
and sudden death in the young through
case registries.
Note: CDC supports SUID monitoring at 18 awardee sites,
covering 30% of all SUID cases in the United States.
Source: Adapted from “SUID and SDY Case Registries,” by
Centers for Disease Control and Prevention, 2018
(https://www.cdc.gov
/sids/CaseRegistry.htm).
HI
TX
CA
NV
OR
WA
ID
MT
WY
UT
AK
AZ NM OK

KSCO
NE
SD
ND
WI
MN
IL
IA
MO
AR
LA
MS AL GA
FL
SC
NCTN
KY
MI
IN OH
PA
NY

WV VA
MA
NH
RI
DE
NJ
CT
MD
MEVT
States that participate in the SUID Case Registry
States and cities/counties that participate in both
the SUID and SDY Case Registries
https://www.cdc.gov/sids/CaseRegistry.htm
https://www.cdc.gov/sids/CaseRegistry.htm
194
1. Permit evaluation and comparisons of trends in health and
disease among popu-
lations or subpopulations (these can include countries and
subgroups within
countries)

2. Provide a basis for planning, provision, and evaluation of
health services in order to
facilitate the efficient allocation of resources
3. Identify problems to be studied by analytic methods and to
suggest areas that may be
fruitful for investigation
Person Variables
Person variables are among the most important descriptive
epidemiologic variables. Age, one
such type of variable, is useful for showing the distribution of
health outcomes. One way to
classify age is according to 10-year intervals; larger age
categories are used as well (e.g., chil-
dren and teenagers, young adults, older adults, and the elderly).
Age is related to many health
outcomes, including morbidity and mortality from infectious
diseases, chronic diseases, unin-
tentional injuries, and disabilities. For example, chronic
diseases (cancer, heart disease, and
diabetes) affect the elderly more frequently than the young.
Another example of age effects
is the tendency for cancer mortality to increase linearly with
age. In comparison, the leading
cause of mortality among younger individuals is unintentional
injuries. From this informa-
tion, epidemiologists can see that younger individuals die far
more than any other age divi-
sion of unintentional injuries. This provides information on
“who.” Once this type of data is
known, more investigation can commence on the “why.”
Many outcomes in morbidity and mortality reflect sex or gender
differences. One example

of sex differences is in overall mortality, which is higher for
males than for females for all
causes. Men also have higher mortality rates than women for
cancer of the lung and bronchus.
Although men have higher rates of mortality, the reverse is true
for morbidity rates, which
for many acute and chronic conditions are higher for women
than for men. An example of sex
differences in deaths from lightning strikes in the United States
shows a significantly higher
number of male deaths versus female. Figure 6.2 breaks this
down not only by gender, but
also by age, state, day of the week, and month. The more detail
an epidemiologist can acquire,
the more information can be determined on potential risk
factors, which may include catego-
ries such as age, location, and day/week of the month. In some
reports, data are broken down
by the hour of the day of lightning strike occurrences.
One of the more well-developed systems for classifying race has
been implemented by the
United States Census Bureau. This system uses five categories
plus a “some other race” cat-
egory. Respondents to the 2010 Census questionnaire could
self-identify their racial group
membership and also select more than one racial group. The
racial categories used in the
2010 questionnaire were White, Black or African American,
American Indian or Alaska
native, Asian, and native Hawaiian or other Pacific Islander.
Respondents were also requested
to indicate whether they were of Hispanic origin; persons of
Hispanic origin could be of any
race. For example, Hispanics can also be classified as Black,
White, or Asian depending on the

race with which they identify themselves.
195
Figure 6.2: Lightning strike fatalities demographics
Gender differences are often visible when examining morbidity
and mortality rates, such as those
presented in these lightning strike fatality demographics.
Epidemiologists can use data to determine
patterns and identify potential risk factors.
* Due to rounding, percentages may not add up to 100%.
** Known fatalities to date.
Note: Monthly averages are based on a 10-year average from
2007 to 2016. Due to rounding, the sum of monthly averages
may not meet the yearly averages.
Source: Adapted from “U.S. Lightning Deaths in 2017,” by
National Weather Service, 2017
(http://www.lightningsafety.noaa.gov
/fatalities.shtml).
AL
CO
FL

NC
OH
PR
TX
3
2
5
2
1
1
2
F
M
1 (6%)
15 (94%)
Age*
2017 Lightning Fatality Demographics
Day of week*

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year
2017
0
0
0
0
2

1
8
3
2
16**
16
0
0
2
3
1
4
12
13
3
0
0
1

39
15
0
0
0
2
4
11
5
4
1
27
14
0
0
0
0
5
3

9
5
3
1
0
26
13
0
0
0
1
5
2
6
4
5
23
12
0

0
1
2
0
3
13
6
2
1
28
11
0
0
0
0
1
5
9
6

4
1
0
0
26
10
0
0
0
0
4
7
11
4
2
1
0
0

29
09
0
0
1
1
2
12
10
3
4
1
0
0
34
08
1
1
0

0
2
9
14
0
1
0
0
0
28
07
0
0
1
1
5
12
10
9

5
2
0
0
45
10 Yr Avg
0
0
1
1
3
7
10
5
3
1
0
0

31*
By month
GenderState
0–9
10–19
20–29
30–39
40–49
50–59
60–69
70–79
80–89
1 (6%)
1 (6%)
3 (19%)
6 (38%)
2 (13%)
0 (0%)
2 (13%)

0 (0%)
1 (6%)
2 (13%)
2 (13%)
4 (25%)
4 (25%)
1 (6%)
2 (13%)
1 (7%)
Sun
Mon
Tues
Wed
Thu
Fri
Sat

http://www.lightningsafety.noaa.gov/fatalities.shtml
http://www.lightningsafety.noaa.gov/fatalities.shtml
196
The United States is becoming increasingly diverse with respect
to race and ethnicity. Racial
characteristics are associated with substantial variations in
several indices of morbidity and
mortality, such as birth rates. One application of data on racial
differences in health outcomes
is to identify health disparities and develop community
programs for groups at greatest risk
of adverse health outcomes. For example, statistics in Figure
6.3 show that Black people are
killed far more through homicide than all other races. Of
interest, through 2014, there was a
general decline in homicide trends for non-Hispanic White, non-
Hispanic Black, and Hispanic
populations (Minino, 2017). Then, a significant increase
occurred between 2014 and 2015.
In 2015, homicide rates were 5.7 deaths per 100,000 for the
total population, 20.9 for non-
Hispanic Blacks, 4.9 for Hispanics, and 2.6 for non-Hispanic
Whites (Minino, 2017). Epidemi-
ologists use this type of information to track health disparities
and racial discriminations. In
light of the recent homicides of Black people that have been in
the news over the past several
years, this information becomes critical not only for health
research but also to assist law
enforcement in determining a focus of racial tensions.

Figure 6.3: Age-adjusted rates for homicides by race/ethnicity,
U.S. 1999–2015
Displaying the data in this graph by race/ethnicity makes it
evident that homicides of Black individuals
spiked between 2014 and 2015. Epidemiologists can use this
type of data to identify racial differences
in health outcomes, identify risk factors, and share their
research with other organizations to help
communities address potential issues.
Source: Adapted from “QuickStats: Age-Adjusted Rates for
Homicides by Race/Ethnicity – United States, 1999–2015,” by
A. Minino, 2017,
Morbidity and Mortality Weekly Report, 66(31), 839
(https://www.cdc.gov/mmwr/volumes/66/wr/mm6631a9.htm).
1999
25
20
15
10
5
0
2001
Year
R

at
e
p
er
1
0
0,
0
0
0
st
an
d
ar
d
p
o
p
u
la
ti
o
n
2003 2005 20092007 2011 2013 2015

All races/origins White, non-Hispanic Black, non-Hispanic
Hispanic
The person variable of socioeconomic status is defined by type
of occupation, income level,
and amount of formal education. Individuals who have higher
income and education levels
and are employed in occupations such as the learned professions
have a higher socioeco-
nomic status on average than those who are lower with respect
to these three characteristics.
Low socioeconomic status is associated with higher rates of
morbidity from infectious and
https://www.cdc.gov/mmwr/volumes/66/wr/mm6631a9.htm
197
chronic conditions and generally a greater frequency of adverse
health outcomes in compari-
son with high socioeconomic status. The association between
low socioeconomic status and
health disparities is discussed in Chapter 2.
Marital status—whether one is single or nonmarried, married, or
unmarried but living with
a partner—has been found to be a factor in health. Rates of
morbidity and mortality vary
according to marital status, and evidence has suggested that

married adults tend to be health-
ier overall than nonmarried adults.
Another person variable is immigrant status. Migration is
related to patterns of chronic dis-
ease and life expectancy. When persons immigrate to a new
country, often they acquire the
health-related characteristics of the inhabitants of the host
country, perhaps as a result of
changes in diet and lifestyle. The process of adopting the
cultural practices of the host coun-
try is known as acculturation. For example, Japanese
immigrants (a low-risk group for coro-
nary heart disease in their home country) who relocated to the
United States and became
acculturated had a higher incidence of coronary heart disease
than immigrants who were less
acculturated. The health-related aspects of immigration are
significant for the many Ameri-
can communities that have large immigrant populations.
Finally, religious background affects personal lifestyle
characteristics and consequently is
associated with variations in morbidity and mortality. For
example, the adherents of some
religious groups (e.g., Seventh-day Adventists who practice
vegetarianism) have lower rates
of cancer and chronic disease mortality in comparison with the
general population.
Place Variables
The variable of place includes international, within-country,
regional, and local patterns in
health outcomes. Within-country variations can be subdivided
further into urban and rural
comparisons. The United States Census Bureau defines

urbanization by using geographic
locations called metropolitan statistical areas (MSAs), which
are urbanized areas based on
the number of inhabitants in a particular area. An MSA is a
geographical region with a rela-
tively high population density at its core and close economic
ties throughout the area. It is
typically centered around a single city that wields substantial
influence on the region (e.g.,
Chicago).
Conditions that show regional variations include Lyme disease,
obesity, HIV infections, and
many others. Among the causes of these variations are
differences in climate, local environ-
mental conditions, socioeconomic status, lifestyle and cultural
factors, and availability of
health care services. For example, local physical environmental
conditions may be conducive
to the survival of microbes and disease vectors. By examining
location, epidemiologists can
begin identifying similar characteristics within a certain region
to determine the cause or fac-
tors connected with an outbreak. Another example is the
distribution of obesity in the United
States. Figure 6.4 shows that obesity is concentrated in states in
the deep South, including
Arkansas, Louisiana, Mississippi, and Alabama. This
information shows epidemiologists a
regionalized view of factors that can contribute to obesity.
Knowing about these concentra-
tions in specific Southern states, epidemiologists can examine
social, environmental, and
economic factors associated with those areas—such as culture,
lifestyle, climate, and health
resources—to determine how to tackle the problem.

198
Time Variables
The epidemiologic variable of time includes the following time
trends: secular (long term),
seasonal, clustering, and epidemic. Investigations of time
variation help to identify changing
patterns in morbidity and mortality, demonstrate the success of
preventive efforts for chronic
and other diseases, and signal the occurrence of epidemics.
Secular trends are the gradual
change in the frequency of a disease over long periods of time.
A great example is polio. After
the introduction of the vaccination against the disease, the
frequency over time dropped. This
is an example of a time epidemic. For disease investigations,
epidemiologists can look at the
incidence rates over a period before or after an incident to
determine if the incident was the
cause. Chapter 2 discussed this in relation to the Flint water
crisis. Over time, there was an
increase in waterborne illnesses after Flint switched its water
source to the Flint River.
Cycle fluctuations also occur in terms of time. Typically,
cyclical fluctuations reflect seasonal
patterns in the occurrence of diseases such as allergies or
seasonal influenza. Tracking a dis-

ease by time can provide insights into an epidemiological
investigation that can lead to a
cause and, eventually, a resolution.
Analytic Epidemiology
Analytic epidemiology is the process of using data gathered by
descriptive experts to
study patterns suggesting causes of diseases and other health
conditions. While descriptive
Figure 6.4: Adult obesity by state, 2016
Obesity is greater in the Southern states, giving epidemiologists
a geographic focal point to review
factors in the area that might influence obesity.
Source: “Adult Obesity in the United States,” by Trust for
America’s Health and Robert Wood Johnson Foundation, 2017
(https://
stateofobesity.org/adult-obesity/). Copyright 2017, Robert
Wood Johnson Foundation. Adapted with permission from the
Robert
Wood Johnson Foundation.
HI
TX
CA
NV
OR
WA

ID
MT
WY
UT
AK
AZ NM OK
KS
CO
NE
SD
ND
WI
MN
IL
IA
MO
AR
LA
MS AL GA
FL

SC
NCTN
KY
MI
IN OH
PA
NY
WV VA
MA
NH
RI
DE
NJ
CT
MD
DC
MEVT
20%–24.9%
25%–29.9%
30%–34.9%
35%+

https://stateofobesity.org/adult-obesity/
https://stateofobesity.org/adult-obesity/
199
Section 6.4 Applying Epidemiology to Community Health
epidemiology tells who, what, where, and when, analytic data
are used to discover the “how”
and “why” factors in investigation. Why did a disease occur?
How did it happen? Analytic epi-
demiologists might ask questions like:
• Do toxic chemicals cause cancer?
• What is the effect of diet on heart disease and diabetes?
For the most part, analytic epidemiologic studies use
observational studies such as case-
control studies and cohort studies. In a case-control study,
subjects are enrolled on the basis
of whether they have had the disease to determine if there is an
association between the
disease and potential causal factors. Cohort study subjects are
enrolled based on their mem-
bership in a controlled subpopulation or category of the
population (e.g., racial groupings).
Analytic epidemiologists also make use of intervention studies,
which test the effectiveness
of a particular program or product.
An example of an analytic epidemiological study

may involve taking a group of students and measur-
ing their BMI and dietary habits for breakfast. Then,
an intervention that includes a healthier option
for the school breakfast program is added, and the
researchers monitor BMI and dietary habits again
after a period of time to see if changes occurred.
They are seeking to determine whether the inter-
vention makes a difference.
It is important to realize that one of the goals of epi-
demiologic research is to portray the frequency and
patterns of disease occurrence in the population
and link them with specific exposures. An exposure
(sometimes called an independent variable) is the
potential causal factor in an epidemiologic study.
Exposures can include many factors, including
environmental, lifestyle, and economic categories,
as well as medical treatments and genetic traits. In
order to examine the occurrence of disease outbreaks and
environmentally caused diseases
in the population, the field of epidemiology uses several
characteristic study designs. Because
this text does not focus on public health research, study
methodologies will not be discussed.
For investigative techniques used by epidemiologists, it is
important to have a basic but not
necessarily a full working knowledge of the terminology.
6.4 Applying Epidemiology to Community Health
The British epidemiologist Jerry Morris wrote the Uses of
Epidemiology in 1957. This classic
book was a product of a time in Britain’s history when there
was growing recognition of the
importance of social and economic factors in health. Morris’s
visionary account of the seven
uses of epidemiology (Table 6.3) remains relevant to modern

community health issues.
Wavebreakmedia/iStock/Thinkstock
Data gathered during an analytic
epidemiology study that examines
how breakfast affects children’s
BMI measurements could be
used to determine if changes to
breakfast dietary habits affect BMI
measurements.
200
Table 6.3: The seven uses of epidemiology*
1. Study the history of the health of populations
2. Diagnose the health of the community
3. Study the working of health services
4. Estimate individual risks
5. Identify syndromes
6. Complete the clinical picture
7. Search for causes

* Green shaded items are discussed in the text.
Source: Adapted from “Uses of Epidemiology,” by J. N. Morris,
2007, in
International Journal of Epidemiology, 36, 1165–1172.
Four Uses of Epidemiology
Four of Morris’s seven uses of epidemiology are directly
relevant to the field of community
and public health. The other three revolve around medical care
and health services, which are
outside of the scope of public health. These four uses of
epidemiology in the community and
public health realm include studying historical trends in health,
describing the health of the
community, assessing individual risks, and examining the
causes of disease in the community.
Studying Historical Trends
The historical use of epidemiology refers to the study of time
trends in health and illness. One
example of the historical use of epidemiology is the study of
changes in disease frequency,
or secular trends, over long time periods (Morris, 2007). In
general, chronic conditions have
replaced acute infectious diseases as the major causes of
morbidity and mortality in contem-
porary industrialized societies. With respect to the health of the
community, it is apparent
that chronic health conditions such as obesity, nutritional
deficiency, and heart disease have
now become major challenges to the population’s health,
although infectious diseases remain
important causes of morbidity and mortality.
Describing the Health of the Community

Describing the health of a community pertains to the
identification of demographics, behav-
ioral risks, and environmental factors in a community that affect
health-related outcomes.
Using epidemiology to describe the health of a community
relates to Healthy People 2020’s
overarching goals:
1. Attain high-quality, longer lives free of preventable disease,
disability, injury, and
premature death.
2. Achieve health equity, eliminate disparities, and improve the
health of all groups.
3. Create social and physical environments that promote good
health for all.
4. Promote quality of life, healthy development, and healthy
behaviors across all life
stages. (HealthyPeople.gov, 2018)
201
Categories of variables that affect community health include
demographic and social compo-
sition, community infrastructure, and environmental
characteristics. Refer to A Closer Look
for more detailed information regarding these variables and how
they could affect the health

of a community.
A Closer Look: Variables and Community Health
Demographic and social variables: Those in poorer communities
often suffer greater ill health
and shorter life expectancies. These variables include the
following:
• Age and sex distribution
• Socioeconomic status
• Family structure, including marital status and number of
single-parent families
• Racial, ethnic, and religious composition
Variables related to community infrastructure: Poorer facilities
and physical environments
directly and indirectly affect health behaviors and subsequently
the risk of developing
chronic disease. Some of these variables include the following:
• Availability of social and health services, including hospitals,
emergency rooms, and
community clinics
• Quality of housing stock, including presence of lead-based
paint and asbestos
• Social stability (residential mobility), such as community
policing and employment
opportunities
Health-related outcome variables: These outcome variables
measure dimensions of health
status in the community. These include the following:

• Homicide and suicide rates
• Infant mortality rate
• Mortality from selected conditions
• Scope of chronic infectious diseases
• Alcoholism and substance abuse rates
• Teenage pregnancy rates
• Occurrence of sexually transmitted diseases
• Birthrate
Environmental variables: The physical environment can provide
factors that adversely affect
or improve the health of a population. These include the
following:
• Air pollution from stationary and mobile sources
• Access to parks and recreational facilities
• Availability of clean water
• Availability of markets that supply healthful groceries
• Number of liquor stores and fast food outlets
• Nutritional quality of foods and beverages vended to
schoolchildren
• Soil levels of radon
Source: Adapted from Epidemiology for Public Health Practice
(4th ed.), by R. H. Friis and T. A. Sellers, 2009, Sudbury, MA:
Jones &
Bartlett.
202

Estimating Individual Risk
Epidemiologic methods are linked closely with the field of risk
assessment, which seeks to
identify and analyze potential hazards and fallout should a
hazard occur. In environmental
risk assessment, epidemiological studies can be used to estimate
potential health risk factors
in the environment and how they are related, or associated. An
example of this is projections
about the probability of developing lung cancer among smokers
versus nonsmokers.
Searching for Causes
Among the most important uses of epidemiology is
uncovering the causes, or etiology, of disease. When
describing the causes of disease, epidemiologists
employ exposures and risk factors. Epidemiologic
research explores possible associations among
exposures and health outcomes through the appli-
cation of appropriate study designs, measures, and
other methodologies. The correct study design can
provide insight into whether an observed associa-
tion is due to chance or is a causal association. A
classic example of using epidemiology to study the
etiology of disease is research on smoking and lung
cancer. Smoking is a risk factor for lung cancer, and
understanding the disease etiology will help a cli-
nician prescribe the most effective preventive or
therapeutic interventions.
The findings of epidemiologic research also aid in policy
development by providing meth-
odological skill sets and contributing to the fund of information
needed to guide informed
decision-making. Backed by supportive, evidence-based

epidemiologic research, policy actors
are able to introduce health-related policies that protect the
community’s health. Legislators
and government officials are charged with the responsibility of
creating policies and enacting
and enforcing many laws that have substantial impacts on public
health. Moreover, following
the adoption of desired health policies and programs, public
health professionals can apply
epidemiologic methods to the evaluation of program
effectiveness.
An example of health policies that have been implemented in a
community comes from the
California city of Long Beach, which enacted a no-smoking
ordinance, LBMC 8.68 (City of
Long Beach, 2013). Within the past decade, the city of Long
Beach has created smoke-free
indoor public areas, including bars and restaurants, pool halls,
office buildings, and elevators
and laundry rooms. No-smoking areas include parks, beaches,
bus stops, farmer’s markets,
and areas within 20 feet of state, county, and city buildings. The
rationale for this ordinance
stemmed from evidence that linked adverse health effects with
secondhand cigarette expo-
sure. In 2011, the state of California passed Senate Bill (SB)
332. This bill “prohibits any per-
son from smoking a cigarette, cigar, or other tobacco-related
product, or from disposing of
cigarette butts, cigar butts, or any other tobacco-related waste,
within a playground” (Califor-
nia Legislation Senate Bill 332, 2011, para. 1). Furthermore, SB
332 authorizes landlords to
prohibit smoking on, in, or near their buildings.

Kallista Images/SuperStock
The pink in this CT scan represents
cancerous growth in the lungs of
a 54-year-old man. In the quest to
discover the etiology of lung cancer,
epidemiological researchers could
identify smoking as a major risk factor.
203
Epidemiological Investigations
There are 13 critical steps that epidemiologists take when
working on an outbreak investi-
gation (Table 6.4). Investigations take time because
epidemiologists must be thorough and
include every element possible for a solid conclusion. If they
are wrong, then the disease
continues to spread and lives are at stake.
Prepare for Fieldwork
Field investigators must have the appropriate scientific
knowledge, supplies, and equipment to
go into the field prior to embarking on an investigation outside
of the office. If material samples
such as blood samples or soil samples are required, the
investigator must take collection units
as well as storage cases for these elements. Other such
equipment may include personal protec-
tive devices such as gloves, face masks, and heavy clothing to

protect themselves against con-
tracting a viral agent. Finally, epidemiologists need to have an
action plan before they enter the
field. Typically, managers and operations directors will help the
field worker with such a plan;
however, the field investigator must be a good manager as well.
Most investigations are done as
a team. Each role must be clearly outlined and differentiated so
there is no duplication of efforts.
This will also help to ensure every element on the investigation
plan is covered.
Table 6.4: Epidemiological steps of an outbreak investigation
1. Prepare for fieldwork
2. Establish the existence of an outbreak
3. Verify the diagnosis
4. Construct a working case definition
5. Find cases systematically and record information
6. Perform descriptive epidemiology
7. Develop hypotheses
8. Evaluate hypotheses epidemiologically
9. As necessary, reconsider, refine, and re-evaluate hypotheses
10. Compare and reconcile with laboratory and/or
environmental studies
11. Implement control and prevention measures

12. Initiate or maintain surveillance
13. Communicate findings
Source: Adapted from “Lesson 6: Investigating an Outbreak,”
by Centers for Disease Control and
Prevention, in Principles of Epidemiology in Public Health
Practice: An Introduction to Applied
Epidemiology and Biostatistics (3rd ed.), 2016
(https://www.cdc.gov/ophss/csels/dsepd/ss1978
/lesson6/section2.html).
https://www.cdc.gov/ophss/csels/dsepd/ss1978/lesson6/section2.
html
https://www.cdc.gov/ophss/csels/dsepd/ss1978/lesson6/section2.
html
204
Establish the Existence of an Outbreak
One of the first tasks of the field investigator is to determine if
there truly is an outbreak and/
or epidemic. This is typically done by looking at descriptive
information that has been pre-
sented, such as numbers of people affected, ages, gender, and
geographic locations. As noted
earlier, an epidemic is when the occurrence of a disease is more
than expected in a given
area or among a specific population. An epidemic may also
occur if there is an outbreak of an

unknown illness that has yet to be diagnosed. While the latter
may not be a formal epidemic,
caution is always advised, as emerging diseases could cause
epidemics or even pandemics. A
good example is the Zika virus, a newly emerging disease that
U.S. epidemiologists investi-
gated in order to protect the nation’s health. Once the
establishment of an outbreak is final-
ized, a field investigation is launched.
Verify the Diagnosis
In many cases, this step is performed at the same time as Step 2
(establishing that an out-
break actually occurred). Investigators typically review any
clinical or laboratory results and
consult with laboratory technicians on accuracy of testing and
final outcomes. Then, inves-
tigators will often visit one of the individuals with the disease,
if that person is alive. Talking
directly with the victims of an outbreak can help provide a
better understanding of how and
where they were affected.
Construct a Working Case Definition
A case definition is a standard set of criteria for deciding
whether someone actually has the
illness or disease under review. This means that the definition
would include the descriptive ele-
ments of person, place, and time, as described earlier in this
chapter. In addition, the symptoms
of the victim are noted and compared with those of others who
have the disease to review simi-
larities or differences (if any). For example, the case definition
of meningococcal disease (menin-
gitis) is listed as “an illness with sudden onset of fever (>38.0
degrees C) and one or more of the

following: neck stiffness, altered consciousness, other
meningeal sign or petechial or puerperal
rash” (CDC, 2016f, Step 4, para. 4). Any time an epidemiologist
goes out to investigate any out-
break, the case definition must be determined and understood so
as to identify all victims.
Find Cases Systematically and Record Information
With a solid case definition, it is much easier for
epidemiologists to identify new cases when
they are in the field. Usually, this case definition assists health
care providers such as doctors
and nurses in the identification process. Often, this definition is
publicized to the media to
help locate individuals who may not realize they have the
disease. Recording the informa-
tion becomes more important for documentation purposes and
may help with the location
of Patient 0, or the first person to have contracted the disease.
Information collected from
each person who falls within the case definition includes name,
address, phone number, age,
sex, race, occupation, signs and symptoms displayed, and risk
factor information. Risk factor
information includes where patients were over a specific time
frame, what they ate or drank,
and what elements they were exposed to, such as pollutants.
This information can provide
common variables among all affected to help home in on the
root cause or to find Patient 0.

205
Perform Descriptive Epidemiology
In this step, the investigator writes and
maps out the information that has been
given during the prior stages. This is a criti-
cal step because after summarizing the col-
lected data, the epidemiologist has a com-
prehensive characterization of the outbreak,
trends over time, location of the disease
outbreak, and who specifically was affected.
This characterization often provides clues
about the cause of the disease. The measles
outbreak at Disneyland in California was
discovered based on descriptive epidemiol-
ogy. Every person affected by this outbreak
had a connection to the amusement park,
but it wasn’t until the field epidemiologist
summarized all of the investigative materi-
als that this connection was discovered.
Develop Hypotheses
Hypotheses, proposed explanations that are a starting point for
further investigation, are gen-
erated in a number of ways. At this stage, the investigator
considers the disease characteris-
tics itself. If it is a known agent, such as measles, the
investigator will review the disease’s
normal transmission, the hosts, the agents, and the risk factors
for contracting the disease.
In the Disneyland case, descriptive epidemiology was able to
pinpoint where the exposure
occurred, and the hypothesis assisted in determining why it
happened: lack of herd immunity.

Evaluate Hypotheses Epidemiologically
Sometimes, more than one hypothesis is determined. At this
time, the field investigator must
critically examine the hypotheses and evaluate the plausibility
of each one. In the measles out-
break at Disneyland, the investigators likely considered the
plausibility of a measles outbreak.
They would have taken childhood vaccinations into
consideration as well as laws and opt-out
laws. Because of information available to epidemiologists, such
as the numbers of unvacci-
nated children, and percentages of children congregating at
Disneyland, epidemiologists could
have actually predicted an outbreak at some point. However,
because measles had been con-
sidered eradicated, it was not on anyone’s radar at the time of
the epidemic. In other cases,
circumstances are not as straightforward. The investigators must
look at observed patterns
from past outbreaks (if they exist) and how the disease
transmission occurs. By comparing
past experiences, epidemiologists can focus on the plausibility
of their hypotheses. Sometimes
there is time to conduct a study to further test the hypotheses
that are suggested; however,
when dealing with viral diseases (diseases with a fast spread
rate or that are deadly), there is
often no time. Researching the literature for past experiences is
the best option at this point.
Marc Rasmus/imageBROKER/SuperStock
Descriptive epidemiology helped investigators
determine that all of the patients affected by
the 2014–2015 measles outbreak had recently
visited the Disneyland Resort in California.

206
Reconsider, Refine, and Re-evaluate Hypotheses
In some cases, when the hypotheses lead to a roadblock,
epidemiologists need to start over and
perhaps look in a different direction. In analytical
epidemiology, this is often the case. Sometimes,
meeting with patients again, visiting their homes, and rehashing
details can reveal new informa-
tion. Field investigators must continuously focus on the
questions that remain unanswered in
order to get to the root problem. It is much like unpeeling an
onion one layer at a time.
Compare and Reconcile With Laboratory and Environmental
Studies
Once an epidemiologist has a working hypothesis, the next step
is to return to the laboratory
or bring in scientific specialists to verify and test the
hypothesis. Consider John Snow and the
cholera outbreak in London. If waterborne illness is suspected,
then a laboratory can confirm
that information. In Snow’s time, individuals were clearly
affected with cholera, so he would
have been the one to suggest testing the main water source (the
Broad Street Pump). This
would have been solid proof that everyone who drank the water
coming from that pump was

getting sick, causing the outbreak. As noted in Chapter 1, there
were no tests of the pump;
however, had such an outbreak occurred today, laboratory
testing would have taken place
during this phase of the process.
Implement Control and Prevention Measures
At this stage, epidemiologists have now identified the disease
and the cause and understand
what is needed to control it. The goal is to control the outbreak
so that no other individu-
als become infected. In John Snow’s time, the control was the
removal of the pump handle.
Today, if there were a cholera outbreak, the entire water source
would be shut off. The point
is the same: control and stop the outbreak. Then, put prevention
measures into place. Dur-
ing the Flint, Michigan, water crisis, the control was to stop
using water from the Flint River.
The prevention was the return to using the Detroit water system.
Some interventions are not
that easy to realize. Blocking the transmission of an infectious
disease seems easier in today’s
world; however, what about the epidemic of obesity? There is
not a one-size-fits-all control
and prevention measure for this type of epidemic. That is why
the crisis still exists today.
Initiate or Maintain Surveillance
Once control and prevention measures have been implemented,
actions must be monitored
to ensure they worked. In the case of the Flint, Michigan, water
crisis, the water system from
Detroit was reinstated, but the water quality is still being
monitored for disease. In addition,
cleanup efforts of the Flint River are part of the surveillance

project. It is also important to
note that even if a root cause is found and a control is put into
place, that does not mean the
disease is eradicated. For the Disneyland measles outbreak,
epidemiologists are still monitor-
ing the nation’s incidence of the disease beyond California. It is
easier to halt a disease when
it is discovered early than to wait until it becomes a pandemic.
207
Summary & Resources
Communicate Findings
The last step involves communicating the investigation results
and protective measures to all
stakeholders. Stakeholders include those affected by the
disease, those who may have been in
the community at the time of the outbreak but did not contract
the disease, the health care
providers who treated the illnesses, and outside communities.
Investigators put together a full
written report on their investigation and their final tasks for
control and prevention. From there,
it is typically the public relations personnel from the
investigating agency (typically the CDC)
who put together the communications to the public and others
who need to have the details.
Now that the 13 steps of the epidemiological investigation
process have been outlined, exam-

ine the reading located at the end of this chapter to follow an
actual case where the steps were
used. Can you spot the process of the 13 steps along the way?
Summary & Resources
Chapter Summary
Epidemiology is a fundamental discipline of public health
focusing on the study of diseases and
disease outbreaks. As early as the 400s BCE, humans were
showing signs of understanding the
interconnectedness of the environment and disease in human
beings. Hippocrates wrote that the
seasons, the influence of the sun, the quality of water, and the
elevation at which people live are
factors in health. The field became more recognizable after the
work of John Snow on the mitiga-
tion of cholera in London in the mid-1800s. Epidemics are
widespread occurrences of a disease,
such as annual influenza. An endemic is specific to a
population, such as the Ebola outbreak in
West Africa. Pandemics are diseases that rage across several
countries.
Public health professionals have a variety of tools that help with
disease surveillance. These sys-
tems provide data on incidence rates of a plethora of diseases as
well as statistics such as birth and
death rates. U.S. Census data is used for more than just
counting the population. The information
is also used by epidemiologists to help identify descriptive
statistics such as gender, race, and age
across the country. Other sources of data used for disease
surveillance include the National Notifi-
able Diseases Surveillance System, the National Health
Interview Survey, and case registries.

Descriptive epidemiology characterizes the disease occurrence
by person, place, and time
variables (i.e., the who, what, where, and when concepts).
Analytic epidemiology takes these
descriptive elements and analyzes them to determine trends or
patterns of a disease within a
population (i.e., the how and why concepts). Using this
information, epidemiologists convert
data to various proportions and rates. The measures used to
determine statistical data and
its significance in a population include count, ratio, proportion,
prevalence, and incidence.
There are seven uses of epidemiology, four of which are
particularly relevant to public health:
studying historical trends, describing the health of a
community, estimating individual risk,
and searching for causes.
208
Summary & Resources
Epidemiological sources and measurements are applied to actual
investigations of diseases
and outbreaks. There are 13 steps followed by all
epidemiological investigators: prepare for
fieldwork, establish the existence of an outbreak, verify the
diagnosis, construct a working
case definition, find cases systematically and record
information, perform descriptive epide-

miology, develop hypotheses, evaluate those hypotheses, refine
the hypotheses, compare and
reconcile with laboratory tests and/or environmental studies,
implement control and pre-
vention measures, maintain or initiate surveillance, and then
communicate the findings. The
process seems tedious; however, it is effective in determining
causes and resolutions.
Critical Thinking and Review Questions
1. Describe the field of epidemiology and its importance to
public health.
2. Describe two surveillance systems that epidemiologists use to
obtain information to
track diseases.
3. Consider the annual influenza strain in the United States,
using the steps of the epi-
demiological investigation. How would you determine the
spread of the virus?
4. What would the Behavioral Risk Factor Surveillance System
be used for?
5. Explain John Graunt’s role in vital statistics.
6. State the seven uses of epidemiology and then describe the
four key uses outlined in
this chapter. Why are they important for epidemiologists?
7. Consider your own community. What types of determinants
in the environment
would cause poor health outcomes? What about positive health
outcomes?
8. What types of diseases would epidemiologists be interested
in investigating by con-

currently factoring in variables of both time and age?
9. In the “11 blue men” reading, describe the key symptoms of
the men. How did
knowledge of these symptoms help with the investigation?
10. In the “11 blue men” reading, what was the final culprit, and
how was it finally
discovered?
Additional Resources
Principles of Epidemiology in Public Health Practice, Third
Edition
https://www.cdc.gov/ophss/csels/dsepd/ss1978/index.html
This source offers a self-guided course on epidemiology from
the Centers for Disease Control
and Prevention.
Survey and data collection systems at the Centers for Disease
Control and Prevention
https://www.cdc.gov/nchs/surveys.htm
Review national surveys collected routinely by the CDC.
https://www.cdc.gov/ophss/csels/dsepd/ss1978/index.html
https://www.cdc.gov/nchs/surveys.htm
209

Summary & Resources
Key Terms
analytic epidemiology The process of
using data gathered by descriptive experts to
study patterns suggesting causes of diseases
and other health conditions.
Behavioral Risk Factor Surveillance Sys-
tem The world’s largest ongoing telephone
health survey system. BRFSS began collect-
ing information on risk behaviors and track-
ing health conditions in the United States in
1984.
case definition A standard set of criteria
for deciding whether someone actually has
the illness or disease under review.
case fatality rate The number of deaths
caused by disease among those who have
the disease during a time period.
case-control study A type of study where
subjects are enrolled on the basis of whether
they have had a disease to determine
whether there is an association between the
disease and exposure.
cluster outbreaks A constant presence
of a disease or infectious agent within a
population.
cohort study A type of study where sub-
jects are enrolled based on their member-
ship in a controlled subpopulation or cat-

egory of the population.
count The total number of cases of the
disease or other health phenomenon being
studied.
descriptive epidemiology The character-
ization of disease occurrence in populations
according to classifications by person, place,
and time variables.
epidemiology The study of the occurrence
and distribution of illnesses, injuries, and
diseases in specific populations.
exposure The potential causal factor in an
epidemiologic study (sometimes called an
independent variable).
hyperendemic outbreaks Outbreaks that
involve a high level of disease occurrence.
incidence A count of new cases of disease
among a group within a specified period.
Flu activity and surveillance at the Centers for Disease Control
and Prevention
https://www.cdc.gov/flu/weekly/fluactivitysurv.htm
This source offers weekly reports on influenza surveillance
activities from epidemiologists at
the CDC.
Health in disadvantaged neighborhoods
https://youtu.be/e48K4RN2nrI

Watch this California Newsreel video for a closer look at how
one’s neighborhood can influ-
ence his or her overall health.
https://www.cdc.gov/flu/weekly/fluactivitysurv.htm
https://youtu.be/e48K4RN2nrI
210
Summary & Resources
incidence rate Describes a disease’s rate of
development within a group during a speci-
fied period.
intervention studies Types of studies that
test the effectiveness of a particular program
or product.
morbidity surveys Means of collecting
information on the health status of a popula-
tion group by using self-administered ques-
tionnaires, interviews, and direct examina-
tions of participants.
National Health Interview Survey A
household health interview survey that has
been collecting data on a broad range of
health topics since 1957. A type of morbidity
survey.
Patient 0 The first person to have con-

tracted a disease.
point prevalence The frequency of disease
or other condition at a given point in time.
prevalence A measure of disease occur-
rence meaning the total number of cases of
disease.
proportion A type of ratio. May be
expressed as a percentage, indicating the
part of a whole.
rate A measure that includes time as a part
of the denominator.
ratio The relationship between two compa-
rable amounts.
secular trends Changes in disease fre-
quency over long periods of time.
sporadic outbreak An outbreak of a dis-
ease that occurs infrequently and irregularly.
211
Reading
Reading
The following story is an actual case that occurred in 1944. The

text is written in the first
person by an epidemiologist (Berton Roueché) investigating the
case of 11 men who came
to a local hospital with unusual blue coloration. It provides a
real-world example of how the
steps of an epidemiological investigation are followed and how
conclusions are drawn along
the way. These steps are critical in order to come to an accurate
conclusion about a potential
epidemic or health crisis in a community.
11 BLUE MEN:
AN EPIDEMIOLOGICAL INVESTIGATION
At about eight o’clock on Monday morning, September 25,
1944, a ragged,
aimless old man of 82 collapsed on the sidewalk on Dey Street,
near the Hud-
son Terminal. Innumerable people must have noticed him, but
he lay there
alone for several minutes, dazed, doubled up with abdominal
cramps, and in
an agony of retching. Then a policeman came along. Until the
policeman bent
over the old man, he may have supposed that he had just a sick
drunk on his
hands; wanderers dropped by drink are common in that part of
town in the
early morning. It was not an opinion that he could have held for
long. The old
man’s nose, lips, ears, and fingers were sky-blue. The
policeman went to a
telephone and put in an ambulance call to Beekman-Downtown
Hospital, half
a dozen blocks away. The old man was carried into the

emergency room there
at 8:30. By that time, he was unconscious and the blueness had
spread over
a large part of his body. The examining physician attributed the
old man’s
morbid color to cyanosis, a condition that usually results from
an insufficient
supply of oxygen in the blood, and also noted that he was
diarrheic and in a
severe state of shock. The course of treatment prescribed by the
doctor was
conventional. It included an instant gastric lavage, heart
stimulants, bed rest,
and oxygen therapy. Presently, the old man recovered an
encouraging, if pain-
ful, consciousness and demanded, irascibly and in the name of
God, to know
what had happened to him. It was a question that, at the
moment, nobody
could answer with much confidence.
For the immediate record, the doctor made a free-hand diagnosis
of carbon-
monoxide poisoning—from what source, whether an automobile
or a gas
pipe, it was, of course, pointless even to guess. Then, because
an isolated
instance of gas poisoning is something of a rarity in a section of
the city as
crammed with human beings as downtown Manhattan he and his
colleagues
in the emergency room braced themselves for at least a couple
more victims.
Their foresight was promptly and generously rewarded. A
second man was
rolled in at 10:25. Forty minutes later, an ambulance drove up

with three more
212
Reading
11 Blue Men: An Epidemiological Investigation (continued)
men. At 11:20, two others were brought in. An additional two
arrived during
the next 15 minutes. Around noon, still another was admitted.
All of the nine
men were also elderly and dilapidated, all had been in misery
for at least an
hour, and all were rigid, cyanotic, and in a state of shock. The
entire body of
one, a bony, 73-year-old consumptive named John Mitchell, was
blue. Five of
the nine, including Mitchell, had been stricken in the Globe
Hotel, a sunless,
upstairs flophouse [cheap hotel] at 190 Park Row, and two in a
similar place,
called the Star Hotel, at 3 James Street. Another had been found
slumped in
the doorway of a condemned building on Park Row not far from
City Hall Park,
by a policeman. The ninth had keeled over in front of the
Eclipse Cafeteria, at
6 Chatham Square. At a quarter to seven that evening, one more
aged blue
man was brought in. He had been lying, too sick to ask for help,

on his cot in
a cubicle in the Lion Hotel, another flophouse, at 26 Bowery,
since 10 o’clock
that morning. A clerk had finally looked in and seen him.
By the time this last blue man arrived at the hospital, an
investigation of the
case by the Department of Health, to which all outbreaks of an
epidemiologi-
cal nature must be reported, had been under way for 5 hours. Its
findings thus
far had not been illuminating. The investigation was conducted
by two men.
One was the Health Department’s chief epidemiologist, Dr.
Morris Green-
berg, a small, fragile, reflective man of 57, who is now acting
director of the
Bureau of Preventable Diseases; the other was Dr. Ottavio
Pellitteri, a field
epidemiologist, who, since 1946, has been administrative
medical inspector
for the Bureau. He is 36 years old, pale, and stocky, and has a
bristling black
mustache. One day, when I was in Dr. Greenberg’s office, he
and Dr. Pellitteri
told me about the case. Their recollection of it is,
understandably, vivid. The
derelicts were the victims of a type of poisoning so rare that
only 10 previous
outbreaks of it had been recorded in medical literature. Of
these, two were
in the United States and two in Germany; the others had been
reported in
France, England, Switzerland, Algeria, Australia, and India. Up
to September
25, 1944, the largest number of people stricken in a single

outbreak was four.
That was in Algeria, in 1926.
The Beekman-Downtown Hospital telephoned a report of the
occurrence to
the Health Department just before noon. As is customary, copies
of the report
were sent to all the Department’s administrative officers. “Mine
was on my
desk when I got back from lunch,” Dr. Greenberg said to me. “It
didn’t sound
like much. Nine persons believed to be suffering from carbon-
monoxide poi-
soning had been admitted during the morning, and all of them
said that they
had eaten breakfast at the Eclipse Cafeteria, at 6 Chatham
Square. Still, it was
a job for us. I checked with the clerk who handles assignments
and found that
Pellitteri had gone out on it. That was all I wanted to know. If it
amounted to
213
Reading
anything, I knew he’d phone me before making a written report.
That’s an
arrangement we have here. Well, a couple of hours later I got a

call from him.
My interest perked right up.”
“I was at the hospital,” Dr. Pellitteri told me, “and I’d talked to
the staff and
most of the men. There were 10 of them by then, of course.
They were sick as
dogs, but only one was in really bad shape.”
“That was John Mitchell,” Dr. Greenberg put in. “He died the
next night. I
understand his condition was hopeless from the start. The
others, including
the old boy who came in last, pulled through all right. Excuse
me, Ottavio, but
I just thought I’d get that out of the way. Go on.”
Dr. Pellitteri nodded. “I wasn’t at all convinced that it was gas
poisoning,” he
continued. “The staff was beginning to doubt it, too. The
symptoms weren’t
quite right. There didn’t seem to be any of the headache and
general dopiness
that you get with gas. What really made me suspicious was this:
Only two or
three of the men had eaten breakfast in the cafeteria at the same
time. They
had straggled in all the way from seven o’clock to 10. That
meant that the
place would have had to be full of gas for at least three hours,
which is pre-
posterous. It also indicated that we ought to have had a lot more
sick people
than we did. Those Chatham Square eating places have a big
turnover. Well, to
make sure, I checked with Bellevue, Gouverneur, St. Vincent’s,

and the other
downtown hospitals. None of them had seen a trace of cyanosis.
Then I talked
to the sick men some more.
“I learned two interesting things. One was that they had all got
sick right after
eating. Within 30 minutes. The other was that all but one had
eaten oatmeal,
rolls, and coffee. He ate just oatmeal. When 10 men eat the
same thing in the
same place on the same day and then all come down with the
same illness . . .
I told Greenberg that my hunch was food poisoning.”
“I was willing to rule out gas,” Dr. Greenberg said. A folder
containing data on
the case lay on the desk before him. He lifted the cover
thoughtfully, then let
it drop. “And I agreed that the oatmeal sounded pretty
suspicious. That was
as far as I was willing to go. Common, ordinary, everyday food
poisoning—
I gathered that was what Pellitteri had in mind—wasn’t a very
satisfying
answer. For one thing, cyanosis is hardly symptomatic of that.
On the other
hand, diarrhea and severe vomiting are, almost invariably. But
they weren’t
in the clinical picture, I found, except in two or three of the
cases. Moreover,
the incubation periods—the time lapse between eating and
illness—were
extremely short. As you probably know, most food poisoning is
caused by

214
Reading
eating something that has been contaminated by bacteria. The
usual offend-
ers are the staphylococci—they’re mostly responsible for boils
and skin infec-
tions and so on—and the salmonella. The latter are related to
the typhoid
organism. In a staphylococcus case, the first symptoms rarely
develop in
under two hours. Often, it’s closer to five. The incubation
period in the other
ranges from 12 to 36 hours. But here we were with something
that hit in 30
minutes or less. Why, one of the men had got only as far as the
sidewalk in
front of the cafeteria before he was knocked out. Another fact
that Pellitteri
had dug up struck me as very significant. All of the men told
him that the ill-
ness had come on with extraordinary suddenness. One minute
they were feel-
ing fine, and the next minute they were practically helpless.
That was another
point against the ordinary food-poisoning theory. Its onset is
never that fast.
Well, that suddenness began to look like a lead. It led me to

suspect that some
drug might be to blame. A quick and sudden reaction is
characteristic of a
great many drugs. So is the combination of cyanosis and shock.”
“None of the men were on dope,” Dr. Pellitteri said. “I told
Greenberg I was
sure of that. Their pleasure was booze.” “That was O.K.,” Dr.
Greenberg said.
“They could have got a toxic dose of some drug by accident. In
the oatmeal,
most likely. I couldn’t help thinking that the oatmeal was
relevant to our prob-
lem. At any rate, the drug idea was very persuasive.”
“So was Greenberg,” Dr. Pellitteri remarked with a smile.
“Actually, it was the only explanation in sight that seemed to
account for every-
thing we knew about the clinical and environmental picture.”
“All we had to do now was prove it,” Dr. Greenberg went on
mildly. “I asked
Pellitteri to get a blood sample from each of the men before
leaving the hospi-
tal for a look at the cafeteria. We agreed he would send the
specimens to the
city toxicologist, Dr. Alexander O. Gettler, for an overnight
analysis. I wanted to
know if the blood contained methemoglobin. Methemoglobin is
a compound
that’s formed only when any one of several drugs enters the
blood. Gettler’s
report would tell us if we were at least on the right track. That
is, it would give
us a yes-or-no answer on drugs. If the answer was yes, then we

could go on
from there to identify the particular drug. How we would go
about that would
depend on what Pellitteri was able to turn up at the cafeteria. In
the mean-
time, there was nothing for me to do but wait for their reports.
I’d theorized
myself hoarse.”
Dr. Pellitteri, having attended to his bloodletting with
reasonable dispatch,
reached the Eclipse Cafeteria at around five o’clock. “It was
about what I’d
215
Reading
expected,” he told me. “Strictly a horse market, and dirtier than
most. The sort
of place where you can get a full meal for 15 cents. There was a
grind house
on one side, a cigar store on the other, and the ‘L’ overhead.
Incidentally, the
Eclipse went out of business a year or so after I was there, but
that had noth-
ing to do with us. It was just a coincidence. Well, the place
looked deserted
and the door was locked. I knocked, and a man came out of the

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