and tuberculosis, that current preventive meas-
ures target.
Literacy A key platform of public health edu-
cation efforts is the presentation of information
through written materials such as posters, hand-
out informational sheets, brochures, and display
placards. Some studies suggest that up to two
thirds of English-speaking individuals lack the
functional literacy level to understand the content
of these materials, complete health and risk
assessment tools such as surveys and question-
naires, or follow written care instructions after
procedures such as surgery. In regions where
there are high concentrations of non-English-
speaking populations, health education materials
and basic health questionnaires are often available
in the dominant languages of such populations.
However, most people who do not understand
materials the doctor gives them will not say so.
Aging of the US population In 1900, less than
4 percent of the American population—3 million
people—was over the age of 65. In 2000, 35 mil-
lion Americans, nearly 13 percent of the popula-
tion, were age 65 and older, a 10-fold increase
over the span of a century. By 2030 the US
Bureau of the Census projects that 30 percent of
the population—70 million people—will be over
age 65. Given the rise in the frequency of health
conditions such as cancer, cardiovascular disease,
and diabetes as well as the conditions relatively
specific to the older population such as
ALZHEIMER’S DISEASE and PARKINSON’S DISEASE, the
potential demand for health-care services may
quadruple. Efforts to reduce the likelihood for pre-
ventable health conditions takes on increasing sig-
nificance within this scenario.
Access to care and mechanisms of delivery
Though 85 percent of Americans have private or
public health insurance, 15 percent do not. In a
delivery model predicated on insurance as primary
payer, insurance coverage determines access to
care. People who do not have health insurance
have difficulty receiving health-care services and
often are then more seriously ill when they do
receive care. Health experts worry that lack of
access to appropriate health-care services, includ-
ing preventive measures such as immunization,
increases the risk for outbreaks of infectious dis-
eases. Of particular concern are SEXUALLY TRANSMIT-
TED DISEASES (STDS), tuberculosis, hepatitis, and
HIV/AIDS, all of which have significant public
health ramifications.Breakthrough Research and Treatment Advances
At the start of the 20th century doctors marveled at
the notion that living organisms so small only the
magnification of a microscope revealed their exis-
tence caused the many diseases that ravaged entire
populations. Perhaps the most profound break-
through in preventive medicine at the start of the
21st century is the mapping of the HUMAN GENOME.
Within reach, and in various stages of research and
development, are “smart” drugs that target specific
substances in the body and pharmacogenomic
products that will “turn off” predisposing genetic
factors for diseases such as HYPERTENSION (high
BLOOD PRESSURE), diabetes, and certain cancers. GENE
THERAPYholds the promise of manipulations that
may end diseases such as CYSTIC FIBROSIS.
No longer the venue of science fiction is the
field of molecular medicine, in which doctors can
redirect cell function. In 2001, after 10 years of
intensive research, a multidisciplinary team of sci-
entists finished decoding the human genome. The
unprecedented achievement revealed startling and
revolutionary insights into the functions of the
human body. The offshoot Microbial Genome Pro-
gram, initiated in 1994, continues to unravel the
genetic encoding of the organisms that function at
the most foundational level of organic existence.
In the space of a century, medicine has come from
identifying the existence of the MICROBEto under-
standing the most intimate details of its functions.
Yet even as technology ushers health care into
the 21st century and beyond, the challenges of the
previous century linger. Infectious illnesses,
though different from those that plagued earlier
generations, remain at the forefront of preventive
medicine. The first Nobel Prize in Medicine or
Physiology was awarded to Emil von Behring in
1901 for discovering the cause of one of the time’s
most deadly diseases, diphtheria. The 1997 award
went to Stanley Prusiner for his discovery of
another new pathogen, the infectious PRION. The
most rampant infection in the world, HIV/AIDS,
remains incurable. Preventive medicine is on a
new, yet familiar, path as the current millennium
moves forward.4 Preventive Medicine