The stars are a few
powerful individuals—presidents, monarchs, dictators—whose actions can shift a
society's development one way or another.
But some influential
actors are nasty and ruthless—and microscopic.
In his book Twelve Diseases That Changed
Our World, Irwin Sherman, a professor emeritus of biology at
the University of California Riverside, describes how bacteria, parasites, and
viruses have swept through cities and devastated populations, felled great
leaders and thinkers, and in their wake transformed politics, public health,
and economies.
U.S.News & World Report spoke with Sherman about how 12 key diseases—smallpox, tuberculosis, syphilis, AIDS, influenza,bubonic
plague, cholera, malaria, yellow fever,
two noninfectious diseases (hemophilia
and porphyria), and the plant disease behind the Irish Potato Famine—have
altered history.
Sherman also answered our
questions about how the threat of
disease outbreaks is
affecting our world today.
1. Smallpox.
It's the only infectious
disease that has been eradicated through vaccination.
The medical science of
vaccination was a direct result of the devastating effects of smallpox.
Essentially, studies of
immunity and vaccines emerged from studies of smallpox. That gives hope that
other diseases, too, will be eradicated by similar means.
2. Tuberculosis.
The struggle against TB
stimulated some of the first quests for antibiotics.
The disease most likely
promoted pasteurization, which heats and kills TB and other pathogens that can
contaminate milk.
The infectious nature of
tuberculosis also prompted the building of sanitariums, where people could be
isolated and treated.
3. Syphilis.
Once treated with heavy
metals like mercury, which had devastating effects on patients, syphilis
inspired the discovery of chemotherapeutic agents.
The sexually transmitted
disease prompted chemotherapy pioneer Paul Ehrlich to look for what he called a
magic bullet, which turned out to be the drug salvorsan.
The history of many drugs
can be traced to Ehrlich's work with dye materials that stained not only
fabrics but organisms as well, spurring him to look for drugs that could bind
to and kill parasites.
4. HIV/AIDS.
"You can't talk
about infectious diseases without discussing AIDS," Sherman declares.
While today's chemotherapy
cocktails—when available—are effective at reducing the number of AIDS-related
deaths, it's a disease that also can be controlled by what he calls the most difficult
intervention: behavioral control. "It's also a disease that is modern and
yet has its parallels with the past in the kind of reactions that populations
have when there's an unforeseen epidemic," he says.
5. Influenza.
Few diseases have had such
widespread effects on the number of deaths in the modern world as the flu,
which remains a major threat worldwide despite the existence of vaccines
against it.
The disease very likely
influenced the course of World War I by sickening and killing soldiers and straining
military healthcare systems.
Some have suggested that
President Wilson's negotiations during the Treaty of Versailles were affected
by the influenza infection he had at the time.
6. Bubonic plague.
Quarantine—the isolation
of infected or potentially infected people as a way to stem the spread of
disease—developed from Europeans' long and storied history with bubonic plague.
Sherman notes parallels
between popular reactions to the plague in medieval times and reactions to
HIV/AIDS in the modern era. Fear and ignorance, anxiety, prejudice, isolation,
and panic can all result from not understanding the nature of a disease, he
says.
7. Cholera.
Spread via paltry or
nonexistent sewage systems and lack of clean water, cholera was—and still
is—rampant in many parts of the world.
But improvements in
sanitation have reduced cholera's impact in a number of regions.
The power of epidemiology
allowed 19th-century English physician John Snow to deduce that the disease was
present in the water, even though the bacterium wasn't identified until many
years later.
8. Malaria.
One of the most lethal
infectious diseases in history, malaria causes over 300 million cases worldwide
and up to 3 million deaths a year.
It's one of the earliest
examples of the importance of controlling vectors—animal or insect carriers (in
this case, mosquitoes)—in preventing the transmission of disease.
One of the reasons
Europeans managed to colonize Africa, according to Sherman, was that they
utilized quinine, an antimalarial drug derived from the bark of the cinchona
tree.
9. Yellow fever.
Although vanquished in
some countries, this mosquito-borne disease hasn't been eradicated and probably
never will be, says Sherman.
The disease influenced the
building of the Panama Canal, the Louisiana Purchase, and, in fact, the
pre-World War II development of the southern United States. "The
stereotypes of the lazy, drawling southerner and the energetic, bright
northerner were typical characterizations due to disease or the absence of
disease," Sherman says. "In the North, mosquitoes couldn't survive
overwintering, so there wasn't yellow fever. In the South, on the other hand,
you had a population that was either decimated or debilitated by the
disease."
10. Hemophilia and 11. Porphyria.
As genetic blood
disorders, hemophilia and porphyria had serious effects on the crowned heads of
Europe.
According to Sherman, the
rise of Spanish dictator Francisco Franco can be traced to the lack of an heir
to the throne because of hemophilia.
Another example is the
collapse of the Romanov dynasty in Russia, which was due to hemophilia in the
family.
The czar was debilitated
and couldn't take over, setting the stage for the rise of the Bolsheviks.
Many of the British
monarchs were unable to manage their kingdoms because of porphyria, which can
cause a variety of mental problems, like hallucination, paranoia, and anxiety.
Some describe George III's
treatment of his American subjects, which helped to trigger the American
Revolution, as being in part affected by his porphyric attacks.
12. Potato blight (cause of the Irish Potato
Famine).
Sherman expanded the range
of maladies to indicate to readers that diseases affect not only humans but
also sometimes what we eat.
Potato blight had a
profound impact because it devastated a staple food that fed much of Ireland in
the mid-1800s.
Other plant diseases could
have similarly far-reaching consequences today, says Sherman.
Many agricultural
economies focus on a particular crop, so a single disease could be a big
threat—and a major historic force.
The Irish famine
influenced America by generating an influx of Irish immigrants to U.S. cities;
those newcomers expanded the Democratic Party, participated in the development
of labor unions, and molded the nation's character in numerous other ways.
Source: USNews
