which supposedly started with the experiments of the king of
Pontus, Mithridates VI Eupator (r. 120–63 b.c.e.), took root
in Rome during the fi rst century c.e., mainly with Androma-
chos, the chief physician of the emperor Nero (r. 54–68 c.e.).
Th e most signifi cant medicine resulting from this strat-
egy was the so-called theriac. First created as a medicine
against venoms and poisons, it also was used as a broad-spec-
trum medicine thanks to its wide range of ingredients (among
them, opium and the fl esh of the viper). Many of those ingre-
dients were credited with the properties of producing heat.
Th e preparation resulting from their mixing purportedly had
the property of burning the matter that provoked the disease
(whatever the nature of the disease or the matter). Th anks
to this supposed property, the use of theriac was expanded
to prevention. In the case of epidemics the compound was
taken to protect against contagion. Th e principle underlying
such use led to other preventive measures, such as spread-
ing perfumed plants and substances credited with a warming
property to burn the miasmas believed to be responsible for
epidemic diseases and their diff usion.
THE AMERICAS
BY CARYN E. NEUMANN
Infectious disease is one of the greatest killers in human his-
tory. But while ancient civilizations in the Americas created
works that paid tribute to other aspects of life, few reports
of disease have survived the passage of the centuries. Mean-
while, much of the modern literature about the Americas
depicts the pre-European contact world as a disease-free par-
adise. It was not. Pandemic disease killed ancient Americans
as it killed other ancient people.
Ancient hunter-gatherers in the Americas were relatively
free from the acute, epidemic infectious diseases that later
took a toll on more advanced agrarian societies. Many acute
infectious diseases require large numbers of susceptible in-
dividuals to support their chains of transmission, which are
characterized by brief and rapid stages of infection. In an-
cient food-foraging groups, populations of no more than 200
to 300 persons would not have been large enough to sustain
such a chain of transmission. If introduced, these acute infec-
tions would have run their courses and then died out. From
the perspective of natural selection, pathogens (disease-caus-
ing agents) that live inside the body of a host for an extended
period of time (such as those that cause typhoid and amoebic
dysentery) would have been favored. Infections (like measles)
that spread rapidly and immunize a majority of the popu-
lation in one epidemic would have been rare or absent. As
populations became more sedentary, they were felled by dev-
astating epidemics of smallpox and measles.
It is not clear whether malaria, another of the great an-
cient killers, was present in the New World. Malaria histori-
cally has been one of the greatest plagues of human societies.
When it does not kill, it leaves a victim weakened. Malaria
is found in the present-day Americas, but it is still uncertain
whether the disease existed in the Americas before the arrival
of Columbus. No Native American population of the present
day has elevated frequencies of any of the genetic mutations
that confer degrees of resistance to malaria in so many Old
World populations.
Other plagues can be clearly identifi ed. Paleopatholo-
gists, scientists who study disease in prehistoric populations,
have fi lled in gaps in the knowledge of the history of pandemic
disease in the Americas by using various types of evidence
to describe disease patterns of ancient populations. By look-
ing at pottery, these scientists have determined that epidemic
leishmaniasis (a skin disorder caused by a protozoan carried
by sand fl ies) was present in ancient Latin America. Pottery
from Peru and Ecuador, dating to about 100 b.c.e., indicates
the presence of facial ulceration, scarring, and malformation
of the mucous membranes among the pre-Inca. Such signs
are an indication of epidemic leishmaniasis. In more severe
forms the disease strikes the liver, lymphatic system, and
spleen, causing lesions, anemia, and death.
Much of the evidence for the presence of disease in the
New World is based on data obtained from research on ar-
chaeological human skeletal remains. One of the limitations
in studying infectious disease in such samples is that acute
diseases are rarely expressed in the skeleton. Almost all infec-
tious diseases are chronic diseases, meaning that most of the
great epidemics which have punctuated human history will
leave, at best, nonspecifi c and indirect evidence in a skeletal
sample. Th e infectious diseases that do aff ect the skeleton are
those caused primarily by bacteria, but even these infectious
organisms rarely aff ect the skeleton unless there is long-term
survival with the disease.
Paleopathologists have examined skeletal evidence to
conclude that tuberculosis, venereal syphilis, yaws (a bacte-
rial skin infection marked by red skin eruptions and joint
pain), and bejel (endemic syphilis) were present in the ancient
Americas. Tuberculosis has been identifi ed in several prehis-
toric Andean populations. Th e earliest evidence for tubercu-
losis in the Americas comes from Chile and dates to about
290 b.c.e. It has not been found in ancient peoples of North
America. Tuberculosis is a chronic disease caused by the mi-
croorganism Mycobacterium tuberculosis. In cases from de-
fi ned geographical areas, most people in each generation are
initially infected in early childhood, typically from inhaling
pathogen-laden droplets expelled by sick individuals. If gen-
eral levels of health are good, more than half of those infected
will never show any clinica l sy mptoms of disease. Individua ls
with weakened immune systems will become visibly ill and
may die. If death does not occur, the bacteria may become
walled up within fi brous capsules in the body and can remain
viable for decades. Severe stress in later life may prompt a re-
currence of tuberculosis.
Yaws and bejel are usually acquired as childhood dis-
eases, with transmission typically occurring in play groups.
Syphilis is acquired from the mother or through sexual trans-
mission, with an onset that usually begins aft er childhood.828 pandemics and epidemics: The Americas