Virgin soil epidemics
Encyclopedia
Virgin soil epidemic refers to an epidemic
resulting from the introduction of a disease into a place where it does not occur or spread naturally. Virgin soil epidemics have occurred with European colonization, particularly during the Age of Discovery
, when European explorers and colonialists brought diseases to "New World
" lands in the Americas, Australia and Pacific Islands
.
When a population has not had contact with a particular pathogen, individuals in that population have not built up any immunity
to that organism, and have not received immunity passed from mother to child. Epidemiologist Francis Black has suggested that some isolated populations may not have mixed enough to become as genetically heterogeneous as their colonizers, which would also have affected their natural immunity. Consequently when a previously unknown disease is introduced to such a population, there is an increase in the morbidity and mortality rate
s; historically this increase has often been devastating, and always noticeable.
Diseases introduced to the Americas by European colonizers—and their African slaves—include smallpox
, yellow fever
, measles
and malaria
, as well as new strains of typhus
and influenza
.
Virgin soil epidemics also occurred in the Old World
prior to the Age of Discovery. For example, the Romans
spread smallpox
through new populations in Europe and the Middle East in the 2nd century AD, and the Mongols
brought the bubonic plague
to Europe and the Middle East in the 14th century.
Epidemic
In epidemiology, an epidemic , occurs when new cases of a certain disease, in a given human population, and during a given period, substantially exceed what is expected based on recent experience...
resulting from the introduction of a disease into a place where it does not occur or spread naturally. Virgin soil epidemics have occurred with European colonization, particularly during the Age of Discovery
Age of Discovery
The Age of Discovery, also known as the Age of Exploration and the Great Navigations , was a period in history starting in the early 15th century and continuing into the early 17th century during which Europeans engaged in intensive exploration of the world, establishing direct contacts with...
, when European explorers and colonialists brought diseases to "New World
New World
The New World is one of the names used for the Western Hemisphere, specifically America and sometimes Oceania . The term originated in the late 15th century, when America had been recently discovered by European explorers, expanding the geographical horizon of the people of the European middle...
" lands in the Americas, Australia and Pacific Islands
Pacific Islands
The Pacific Islands comprise 20,000 to 30,000 islands in the Pacific Ocean. The islands are also sometimes collectively called Oceania, although Oceania is sometimes defined as also including Australasia and the Malay Archipelago....
.
When a population has not had contact with a particular pathogen, individuals in that population have not built up any immunity
Immunity (medical)
Immunity is a biological term that describes a state of having sufficient biological defenses to avoid infection, disease, or other unwanted biological invasion. Immunity involves both specific and non-specific components. The non-specific components act either as barriers or as eliminators of wide...
to that organism, and have not received immunity passed from mother to child. Epidemiologist Francis Black has suggested that some isolated populations may not have mixed enough to become as genetically heterogeneous as their colonizers, which would also have affected their natural immunity. Consequently when a previously unknown disease is introduced to such a population, there is an increase in the morbidity and mortality rate
Mortality rate
Mortality rate is a measure of the number of deaths in a population, scaled to the size of that population, per unit time...
s; historically this increase has often been devastating, and always noticeable.
Diseases introduced to the Americas by European colonizers—and their African slaves—include smallpox
Smallpox
Smallpox was an infectious disease unique to humans, caused by either of two virus variants, Variola major and Variola minor. The disease is also known by the Latin names Variola or Variola vera, which is a derivative of the Latin varius, meaning "spotted", or varus, meaning "pimple"...
, yellow fever
Yellow fever
Yellow fever is an acute viral hemorrhagic disease. The virus is a 40 to 50 nm enveloped RNA virus with positive sense of the Flaviviridae family....
, measles
Measles
Measles, also known as rubeola or morbilli, is an infection of the respiratory system caused by a virus, specifically a paramyxovirus of the genus Morbillivirus. Morbilliviruses, like other paramyxoviruses, are enveloped, single-stranded, negative-sense RNA viruses...
and malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
, as well as new strains of typhus
Typhus
Epidemic typhus is a form of typhus so named because the disease often causes epidemics following wars and natural disasters...
and influenza
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae , that affects birds and mammals...
.
Virgin soil epidemics also occurred in the Old World
Old World
The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....
prior to the Age of Discovery. For example, the Romans
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....
spread smallpox
Smallpox
Smallpox was an infectious disease unique to humans, caused by either of two virus variants, Variola major and Variola minor. The disease is also known by the Latin names Variola or Variola vera, which is a derivative of the Latin varius, meaning "spotted", or varus, meaning "pimple"...
through new populations in Europe and the Middle East in the 2nd century AD, and the Mongols
Mongol Empire
The Mongol Empire , initially named as Greater Mongol State was a great empire during the 13th and 14th centuries...
brought the bubonic plague
Bubonic plague
Plague is a deadly infectious disease that is caused by the enterobacteria Yersinia pestis, named after the French-Swiss bacteriologist Alexandre Yersin. Primarily carried by rodents and spread to humans via fleas, the disease is notorious throughout history, due to the unrivaled scale of death...
to Europe and the Middle East in the 14th century.
External links
- http://ocw.mit.edu/courses/science-technology-and-society/sts-005-disease-and-society-in-america-fall-2005/lecture-notes/lec_3.pdf