Healthcare

GLOBAL INVESTOR 2.12 — 09
Medical milestones
From germs
to genes
The history of humankind is also the history of medical achievement. Aided increasingly by
technology, the last two hundred years in particular represent an astonishing array of intellectual
and practical breakthroughs in understanding the human body, the nature of disease and
how to treat it. Yet “health for all” remains an elusive goal that depends as much on wise and
effective public health policy as on medical innovation.
Bernardino Fantini, medical historian, University of Geneva
Listen to this article on Global Investor’s Knowledge Platform:
At the end of the first millennium (current era), human population
growth began to trace a steady upward curve that even the devastating
plague epidemics of the 14th and 17th centuries could only temporarily
interrupt. By the turn of the 19th century, the size and age structure
of populations – at least in the industrialized world – reflected a sustained,
fundamental alteration in living standards and longer lifetimes.
Today, life expectancy in developed countries has increased from 33
years two centuries ago to 80 years. In certain low-income regions,
however, life expectancy remains very low. And in some countries it
is even decreasing. In 1971, Abdel Omran coined the term “epidemiological
transition” to describe these demographic changes, which
result from socioeconomic developments and innovations in medical
theory and treatment over time.
In pre-scientific medicine, as in folk medicine, no link existed
between cause and effect. Moreover, so many different causes might
be evoked to explain a disease (air, food, bad behavior) that it was
impossible to propose a simple therapy for it. At the beginning of the
19th century, an influential school of thinking then current in Parisian
hospitals showed that to the contrary, diseases were unique entities
with specific characteristics associated with equally specific anatomical
lesions. These lesions could be distinguished by analyzing their
symptoms, identifying their clinical signs and directly observing them
in the bodies of patients at autopsy. Replacing the idea of multiple
causality with a single, specific cause changed the way knowledge
about disease is acquired and ushered in the age of scientific medicine.
In 1847, Ignaz Semmelweis discovered that an infectious agent transmitted
by midwives and doctors was the cause of high mortality in
maternity wards and could be eliminated by assiduous hand washing.
The London cholera epidemic of 1854 led John Snow to geographically
plot clusters of cases, which pointed to a public water pump as
the source of the outbreak . The revolution arising from
the work of Louis Pasteur and Robert Koch on “germ theory” rounded
out the explanation of the cause of disease. The theory suggested
that a contagious or infectious disease is due to the continued and
constant presence of a specific germ (micro-organism) that causes
disease in a person. That germ is the specific and necessary cause >