Encyclopedia of Environmental Science and Engineering, Volume I and II

COMMUNITY HEALTH 175

Official public health services provide some sickness

care but are legally charged to assure that all citizens have

safe and healthy environments in which to live and work.

Health departments must respond to complaints from anyone

within their jurisdiction, and their officers are expected to act

promptly to abate health dangers. These agencies have a duty

to intervene and a right to enter whenever a hazard exists that

threatens the community’s health. Although actual physical

entry can legally be obtained only by permission or by war-

rant, health departments have long been considered to have

a right to enter any dispute that involves community health.

In this respect, official health departments are truly safety

agencies equal to fire or police departments.

In addition to this unique legal status, the health offi-

cer is a member of the central staff or cabinet of the chief

elected official and provides advice on health matters. The

mayor, county executive, or governor can direct that health

officer to begin appropriate corrective actions whenever the

public health is endangered. To help in fulfilling statutory

and directed functions, health departments have four essen-

tial community functions: Epidemiology, disease prevention,

needed services, rescue and protection.

EPIDEMIOLOGY

The importance of epidemiology, or the knowledge of a dis-

ease that exists in a community, was clearly stated as early

as 1879 in a Baltimore City health ordinance that began with

this statement: “It shall be the duty of the Commissioner of

Health, from time to time to make a circuit of observation to

the several parts of the city and its environs” to detect dangers

to health and promptly order their correction. This legal charge

codified the duty of the health officer personally or through

delegated agents to gather information about the healthiness

of the community or its inhabitants. Often known as “shoe

leather epidemiology,” this direction is similar to a military

axiom that tells commanders to “go to the sound of the guns,”

to go where troubles exists. Further, the Baltimore ordinance

directed the health commissioner to take immediate steps to

correct noxious conditions and to report to the mayor with

advice on further actions needed to maintain a healthy city.

All of these steps are a part of epidemiology, or wisdom

“among a people.” Health departments collect information

about communicable diseases, analyze reports of births and

deaths, follow trends in accidental injuries and childhood

development, and provide annual summaries of the health

of a community. Possibly the earliest example of modern

measurement of health statistics occurred in 1882 when

vital records of Baltimore, MD, and Washington, DC, were

analyzed by sensing punch cards. John Shaw Billings, who

would later design the Johns Hopkins Hospital and the New

York Public Library, asked an electrical engineer, Herman,

Hollerith, to devise a means of electrically sensing and count-

ing the holes in a series of punch cards that contained census

information about the respective populations. This venture

was successful and the information obtained is listed in the

annual reports of the 1880 U.S. census for the two cities.

Gathering health facts and analyzing them is such a distinc-

tive health department function that a well-known national

health officer once urged that they be named “Departments

of Epidemiology” to emphasize this importance.^7

The discipline of epidemiology determines and analyzes

the distribution and dynamics, or changing characteristics,

of diseases in human populations. Physical health in a com-

munity is measured inversely by the incidence of a disease

or injury over time or its prevalence at any given moment

or time period.^8 The lower the incidence or prevalence, the

better the community’s epidemiologic health. Health offi-

cers utilize epidemiology to determine where, how and why

disease exists in their communities. Other measures of the

impact of diseases on community health are found in statis-

tics of morbidity and mortality, as well as a disease intensity

in a neighborhood, where a disease is spreading, and any

deaths as noted by gender, age, and race. Epidemiology is a

basic tool for allocation of departmental protective and pre-

ventive resources and services.

Health departments gather and analyze data supplied

in reports to central agencies received from physicians and

health care workers who are required by law to so report on

official forms each occurrence of certain human diseases, at

least 52 of which must be reported to the U.S. Centers for

Disease control. Reporting enables health officials to deploy

public health workers and resources who can act to limit the

spread of infection to susceptible inhabitants. A health officer

can require that patients with certain communicable diseases

can be isolated in a single household, or order a community-

wide investigation of food poisoning or a measles outbreak

in local schools that is preliminary to focused prevention.

When spread of a disease can be minimized by vaccination,

localized or mass specific inoculation programs are offered

to all persons at risk, some of whom may also require spe-

cific antibiotic therapy as prophylactic against infection.

DISEASE PREVENTION

The first case of an infectious disease, the “index case,” is

the well-spring of epidemiology (Sartwell). Certain diseases

spread rapidly in a community and cause severe economic

loss if workers are incapacitated or children are disabled by

severe complications. Infections like measles and rubella

(German measles), are no longer accepted as unavoidable

risks to children but have been markedly reduced by protec-

tive vaccines. Poliomyelitis has nearly been eliminated in the

Americas and small pox has in fact been eliminated from the

world by mass immunizations.^9 Epidemic cholera appeared

in Peru in the last decade and spread through neighboring

countries, and Lyme disease was identified several decades

ago in New England; recent findings show that it also has a

world-wide distribution. Diseases are spread easily by tour-

ists and business people who return to homes by air, unwit-

tingly carrying early infections of exotic diseases. These

may include malaria, typhus, hemorrhagic dengue fever, and

others, many of which require prompt public health attention

to minimize or eliminate transmission to U.S. residents.

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