A pandemic () is an
epidemic
An epidemic (from Greek ἐπί ''epi'' "upon or above" and δῆμος ''demos'' "people") is the rapid spread of disease to a large number of patients among a given population within an area in a short period of time.
Epidemics of infectious d ...
of an
infectious disease
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable d ...
that has spread across a large region, for instance multiple
continents or worldwide, affecting a substantial number of individuals. A widespread
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...
disease with a stable number of infected individuals is not a pandemic. Widespread endemic diseases with a stable number of infected individuals such as recurrences of
seasonal influenza are generally excluded as they occur simultaneously in large regions of the globe rather than being spread worldwide.
Throughout
human history
Human history, also called world history, is the narrative of humanity's past. It is understood and studied through anthropology, archaeology, genetics, and linguistics. Since the invention of writing, human history has been studied t ...
, there have been a number of pandemics of diseases such as
smallpox
Smallpox was an infectious disease caused by variola virus (often called smallpox virus) which belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) ce ...
. The most fatal pandemic in
recorded history
Recorded history or written history describes the historical events that have been recorded in a written form or other documented communication which are subsequently evaluated by historians using the historical method. For broader world hi ...
was the
Black Death—also known as
The Plague
Plague or The Plague may refer to:
Agriculture, fauna, and medicine
*Plague (disease), a disease caused by ''Yersinia pestis''
* An epidemic of infectious disease (medical or agricultural)
* A pandemic caused by such a disease
* A swarm of pe ...
—which killed an estimated 75–200 million people in the 14th century.
The term had not been used then but was used for later epidemics, including the
1918 influenza pandemic—more commonly known as the Spanish flu.
Current pandemics include
HIV/AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...
and
COVID-19
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease quickl ...
.
Definition
A pandemic is an
epidemic
An epidemic (from Greek ἐπί ''epi'' "upon or above" and δῆμος ''demos'' "people") is the rapid spread of disease to a large number of patients among a given population within an area in a short period of time.
Epidemics of infectious d ...
occurring on a scale that crosses international boundaries, usually affecting people on a worldwide scale.
A disease or condition is not a pandemic merely because it is widespread or kills many people; it must also be infectious. For instance,
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...
is responsible for many deaths but is not considered a pandemic because the disease is not
contagious—i.e. easily transmittable—and not even simply
infectious.
In 2009, the
World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level o ...
(WHO) dropped the words "with enormous numbers of deaths and illness" from their definition. In 2008, it also dropped the requirement of an "influenza pandemic" to be a new sub-type with a simple reassortant virus, meaning that many seasonal flu viruses now could be classified as pandemic influenza.
The word comes from the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
παν- ''pan-'' meaning "all", or "every" and δῆμος ''demos'' "people".
Assessment
Stages
The World Health Organization previously applied a six-stage classification to describe the process by which a novel
influenza virus moves from the first few infections in humans through to a pandemic. It starts when mostly animals are infected with a virus and a few cases where animals infect people, then moves to the stage where the virus begins to be transmitted directly between people and ends with the stage when infections in humans from the virus have spread worldwide. In February 2020, a WHO spokesperson clarified that "there is no official category
or a pandemic
Or or OR may refer to:
Arts and entertainment Film and television
* "O.R.", a 1974 episode of M*A*S*H
* Or (My Treasure), a 2004 movie from Israel (''Or'' means "light" in Hebrew)
Music
* ''Or'' (album), a 2002 album by Golden Boy with Mis ...
.
During the 2009 influenza pandemic, Dr. Keiji Fukuda, Assistant Director-General ''ad interim'' for Health Security and Environment, WHO said "An easy way to think about pandemic... is to say: a pandemic is a global outbreak. Then you might ask yourself: 'What is a global outbreak?' Global outbreak means that we see both the spread of the agent... and then we see disease activities in addition to the spread of the virus."
In planning for a possible influenza pandemic, the WHO published a document on pandemic preparedness guidance in 1999, which was revised in 2005 and 2009. It defined phases and appropriate actions for each phase in an ''aide-mémoire'' titled ''WHO pandemic phase descriptions and main actions by phase''. The 2009 revision, including descriptions of a pandemic and the phases leading to its declaration, was finalized in February 2009. The 2009 H1N1 virus pandemic was neither on the horizon at that time nor mentioned in the document. All versions of this document refer to influenza. The phases are defined by the spread of the disease;
virulence
Virulence is a pathogen's or microorganism's ability to cause damage to a host.
In most, especially in animal systems, virulence refers to the degree of damage caused by a microbe to its host. The pathogenicity of an organism—its ability to ...
and
mortality are not mentioned in the current WHO definition, although these factors have previously been included.
In 2014, the United States
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georg ...
introduced an analogous framework to the WHO's pandemic stages titled the Pandemic Intervals Framework.
It includes two pre-pandemic intervals,
* Investigation
* Recognition
and four pandemic intervals,
* Initiation
* Acceleration
* Deceleration
* Preparation
It also includes a table defining the intervals and mapping them to the WHO pandemic stages.
Severity
In 2014, the United States Centers for Disease Control and Prevention adopted the
Pandemic Severity Assessment Framework (PSAF) to assess the severity of pandemics.
The PSAF superseded the 2007 linear
Pandemic Severity Index, which assumed 30% spread and measured
case fatality rate
In epidemiology, case fatality rate (CFR) – or sometimes more accurately case-fatality risk – is the proportion of people diagnosed with a certain disease, who end up dying of it. Unlike a disease's mortality rate, the CFR does not take int ...
(CFR) to assess the severity and evolution of the pandemic.
Historically, measures of pandemic severity were based on the case fatality rate.
However, the case fatality rate might not be an adequate measure of pandemic severity during a pandemic response because:
* Deaths may lag several weeks behind cases, making the case fatality rate an underestimate
* The total number of cases may not be known, making the case fatality rate an overestimate
* A single case fatality rate for the entire population may obscure the effect on vulnerable sub-populations, such as children, the elderly, those with chronic conditions, and members of certain racial and ethnic minorities
* Fatalities alone may not account for the full effects of the pandemic, such as absenteeism or demand for healthcare services
To account for the limitations of measuring the case fatality rate alone, the PSAF rates the severity of a disease outbreak on two dimensions: clinical severity of illness in infected persons; and the transmissibility of the infection in the population.
Each dimension can be measured using more than one metric, which are scaled to allow comparison of the different metrics. Clinical severity can instead be measured, for example, as the ratio of deaths to hospitalizations or using genetic markers of virulence. Transmissibility can be measured, for example, as the
basic reproduction number R
0 and
serial interval The serial interval in the epidemiology of communicable (infectious) diseases is the time between successive cases in a chain of transmission.
The serial interval is generally estimated from the interval between clinical onsets (if observable), in ...
or via underlying population immunity. The framework gives guidelines for scaling the various measures and examples of assessing past pandemics using the framework.
Management
The basic strategies in the control of an outbreak are containment and mitigation. Containment may be undertaken in the early stages of the outbreak, including
contact tracing
In public health, contact tracing is the process of identifying persons who may have been exposed to an infected person ("contacts") and subsequent collection of further data to assess transmission. By tracing the contacts of infected individua ...
and isolating infected individuals to stop the disease from spreading to the rest of the population, other public health interventions on infection control, and therapeutic countermeasures such as
vaccinations which may be effective if available. When it becomes apparent that it is no longer possible to contain the spread of the disease, management will then move on to the mitigation stage, in which measures are taken to slow the spread of the disease and mitigate its effects on society and the healthcare system. In reality, containment and mitigation measures may be undertaken simultaneously.
A key part of managing an infectious disease outbreak is trying to decrease the epidemic peak, known as "
flattening the curve".
This helps decrease the risk of health services being overwhelmed and provides more time for a vaccine and treatment to be developed.
A broad group of the so-called non-pharmaceutical interventions may be taken to manage the outbreak.
In a flu pandemic, these actions may include personal preventive measures such as hand hygiene, wearing face-masks, and self-quarantine; community measures aimed at
social distancing
In public health, social distancing, also called physical distancing, (NB. Regula Venske is president of the PEN Centre Germany.) is a set of non-pharmaceutical interventions or measures intended to prevent the spread of a contagious dise ...
such as closing schools and canceling mass gatherings; community engagement to encourage acceptance and participation in such interventions; and environmental measures such as cleaning of surfaces.
Another strategy, suppression, requires more extreme long-term non-pharmaceutical interventions to reverse the pandemic by reducing the
basic reproduction number to less than1. The suppression strategy, which includes stringent population-wide social distancing, home isolation of cases, and household quarantine, was undertaken by
China during the
COVID-19 pandemic
The COVID-19 pandemic, also known as the coronavirus pandemic, is an ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The novel virus was first identified ...
where entire cities were placed under lockdown; such a strategy may carry with it considerable social and economic costs.
Current pandemics
HIV/AIDS
Although the WHO uses the term "global epidemic" to describe
HIV
The human immunodeficiency viruses (HIV) are two species of '' Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immu ...
(), as HIV is no longer an uncontrollable outbreak outside of Africa, some authors use the term "pandemic".
HIV originated in Africa, and spread to the United States via Haiti between 1966 and 1972.
AIDS is currently a pandemic in Africa, with infection rates as high as 25% in some regions of southern and eastern Africa. In 2006, the HIV prevalence among pregnant women in
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring count ...
was 29%. Effective education about safer sexual practices and
bloodborne infection precautions training have helped to slow down infection rates in several African countries sponsoring national education programs. There were an estimated 1.5 million new infections of
HIV/AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...
in 2020. there have been about a total of 32.7 million deaths related to HIV/AIDS since the epidemic started.
COVID-19
SARS-CoV-2
Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a No ...
, a new strain of
coronavirus, was first detected in the city of
Wuhan, Hubei Province
Wuhan (, ; ; ) is the capital of Hubei Province in the People's Republic of China. It is the largest city in Hubei and the most populous city in Central China, with a population of over eleven million, the ninth-most populous Chinese city and ...
, China, in December 2019. It caused a pandemic of cases of an acute respiratory disease, which is referred to as
coronavirus disease 2019
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease quickly ...
(COVID-19).
More than 200 countries and territories have been affected by COVID-19, with major outbreaks occurring in
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
,
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eigh ...
,
India
India, officially the Republic of India ( Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the ...
,
Mexico
Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...
,
Peru
, image_flag = Flag of Peru.svg
, image_coat = Escudo nacional del Perú.svg
, other_symbol = Great Seal of the State
, other_symbol_type = Seal (emblem), National seal
, national_motto = "Fi ...
, South Africa,
Western Europe
Western Europe is the western region of Europe. The region's countries and territories vary depending on context.
The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the ancient Mediterranean ...
, and the United States.
On 11 March 2020, the World Health Organization characterized the spread of COVID-19 as a
pandemic, marking the first global pandemic since the
2009 swine flu pandemic
The 2009 swine flu pandemic, caused by the H1N1 influenza virus and declared by the World Health Organization (WHO) from June 2009 to August 2010, is the third recent flu pandemic involving the H1N1 virus (the first being the 1918–1920 Spa ...
.
As of 15 November 2022, the number of people infected with COVID-19 has reached more than 635 million worldwide. The current death toll is 6,611,456. It is believed that these figures underestimate true totals as testing did not commence in the initial stages of the outbreak and many people infected by the virus have no or only mild symptoms so may not have been tested. Similarly, the number of deaths may also be understated as fatalities may have not been tested or are attributed to other conditions.
This was especially the case in large urban areas where a non-trivial number of patients died while in their private residences.
Major outbreaks in countries
Notable outbreaks
Plague
In human
history
History (derived ) is the systematic study and the documentation of the human activity. The time period of event before the History of writing#Inventions of writing, invention of writing systems is considered prehistory. "History" is an umbr ...
, it is generally
zoonoses
A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a bacterium, virus, parasite or prion) that has jumped from a non-human (usually a vertebrate) to a human. ...
such as
influenza
Influenza, commonly known as "the flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptom ...
and tuberculosis which constitute most of the widespread outbreaks, resulting from the
domestication
Domestication is a sustained multi-generational relationship in which humans assume a significant degree of control over the reproduction and care of another group of organisms to secure a more predictable supply of resources from that group. A ...
of animals. There have been many particularly significant epidemics that deserve mention above the "mere" destruction of cities:
*
Plague of Athens (430 to 426 BC): During the
Peloponnesian War,
typhoid fever
Typhoid fever, also known as typhoid, is a disease caused by '' Salmonella'' serotype Typhi bacteria. Symptoms vary from mild to severe, and usually begin six to 30 days after exposure. Often there is a gradual onset of a high fever over severa ...
killed a quarter of the Athenian troops and a quarter of the population. This disease fatally weakened the dominance of
Athens
Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital city, capital and List of cities and towns in Greece, largest city of Greece. With a population close to four million, it is also the seventh List ...
, but the sheer virulence of the disease prevented its wider spread; i.e. it killed off its hosts at a rate faster than they could spread it. The exact cause of the plague was unknown for many years. In January 2006, researchers from the
University of Athens analyzed
teeth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, te ...
recovered from a
mass grave
A mass grave is a grave containing multiple human corpses, which may or may Unidentified decedent, not be identified prior to burial. The United Nations has defined a criminal mass grave as a burial site containing three or more victims of executi ...
underneath the city and confirmed the presence of
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...
responsible for typhoid.
*
Antonine Plague (165 to 180 AD): Possibly measles or smallpox brought to the Italian peninsula by soldiers returning from the Near East, it killed a quarter of those infected, up to five million in total.
*
Plague of Cyprian (251–266 AD): A second outbreak of what may have been the same disease as the Antonine Plague killed (it was said) 5,000 people a day in
Rome
, established_title = Founded
, established_date = 753 BC
, founder = King Romulus ( legendary)
, image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, Italy).svg
, map_caption ...
.
*
Plague of Justinian
The plague of Justinian or Justinianic plague (541–549 AD) was the first recorded major outbreak of the first plague pandemic, the first Old World pandemic of plague, the contagious disease caused by the bacterium ''Yersinia pestis''. The d ...
(541 to 549 AD): The first recorded outbreak of
bubonic plague
Bubonic plague is one of three types of plague caused by the plague bacterium ('' Yersinia pestis''). One to seven days after exposure to the bacteria, flu-like symptoms develop. These symptoms include fever, headaches, and vomiting, as ...
started in
Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Med ...
and reached
Constantinople
la, Constantinopolis ota, قسطنطينيه
, alternate_name = Byzantion (earlier Greek name), Nova Roma ("New Rome"), Miklagard/Miklagarth ( Old Norse), Tsargrad ( Slavic), Qustantiniya (Arabic), Basileuousa ("Queen of Cities"), Megalopolis ( ...
the following spring, killing (according to the Byzantine chronicler
Procopius
Procopius of Caesarea ( grc-gre, Προκόπιος ὁ Καισαρεύς ''Prokópios ho Kaisareús''; la, Procopius Caesariensis; – after 565) was a prominent late antique Greek scholar from Caesarea Maritima. Accompanying the Roman ge ...
) 10,000 a day at its height, and perhaps 40% of the city's inhabitants. The plague went on to eliminate a quarter to half the
human population
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture ...
of the known world.
*
Black Death (1331 to 1353): The total number of deaths worldwide is estimated at 75 to 200 million. Eight hundred years after the last outbreak, the
plague returned to Europe. Starting in Asia, the disease reached the Mediterranean and western Europe in 1348 (possibly from Italian merchants fleeing fighting in
Crimea
Crimea, crh, Къырым, Qırım, grc, Κιμμερία / Ταυρική, translit=Kimmería / Taurikḗ ( ) is a peninsula in Ukraine, on the northern coast of the Black Sea, that has been occupied by Russia since 2014. It has a p ...
), and killed an estimated 20 to 30 million Europeans in six years; a third of the total population, and up to a half in the worst-affected urban areas. It was the first of a cycle of European
plague epidemics that continued until the 18th century. There were more than 100 plague epidemics in Europe during this period. The disease recurred in England every two to five years from 1361 to 1480. By the 1370s, England's population was reduced by 50%. The
Great Plague of London
The Great Plague of London, lasting from 1665 to 1666, was the last major epidemic of the bubonic plague to occur in England. It happened within the centuries-long Second Pandemic, a period of intermittent bubonic plague epidemics that origi ...
of 1665–66 was the last major outbreak of the
plague in England and killed approximately 100,000 people, 20% of London's population.
*
Third plague pandemic (1855): Starting in China, it spread into India, where 10 million people died. During this pandemic, the United States saw its first outbreak: the
San Francisco plague of 1900–1904. Today, sporadic cases of
plague still occur in the western United States.
* The 1918–1920
Spanish flu
The 1918–1920 influenza pandemic, commonly known by the misnomer Spanish flu or as the Great Influenza epidemic, was an exceptionally deadly global influenza pandemic caused by the H1N1 influenza A virus. The earliest documented case wa ...
infected half a billion people
around the world, including on remote
Pacific islands
Collectively called the Pacific Islands, the islands in the Pacific Ocean are further categorized into three major island groups: Melanesia, Micronesia, and Polynesia. Depending on the context, the term ''Pacific Islands'' may refer to one of ...
and in the
Arctic
The Arctic ( or ) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada ( Yukon, Northwest Territories, Nunavut), Danish Realm ( Greenland), Finland, Iceland ...
—killing 20 to 100 million.
Most influenza outbreaks disproportionately kill the very young and the very old, but the 1918 pandemic had an unusually high mortality rate for young adults. It killed more people in 25 weeks than AIDS did in its first 25 years. Mass troop movements and close quarters during World WarI caused it to spread and
mutate faster, and the susceptibility of soldiers to the flu may have been increased by stress,
malnourishment and
chemical attacks. Improved transportation systems made it easier for soldiers, sailors and civilian travelers to spread the disease.
Encounters between European explorers and populations in the rest of the world often introduced epidemics of extraordinary virulence. Disease killed part of the native population of the
Canary Islands
The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Mo ...
in the 16th century (
Guanches
The Guanches were the indigenous inhabitants of the Canary Islands in the Atlantic Ocean some west of Africa.
It is believed that they may have arrived on the archipelago some time in the first millennium BCE. The Guanches were the only nativ ...
). Half the native population of
Hispaniola
Hispaniola (, also ; es, La Española; Latin and french: Hispaniola; ht, Ispayola; tnq, Ayiti or Quisqueya) is an island in the Caribbean that is part of the Greater Antilles. Hispaniola is the most populous island in the West Indies, and t ...
in 1518 was killed by smallpox.
Smallpox
Smallpox was an infectious disease caused by variola virus (often called smallpox virus) which belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) ce ...
also ravaged Mexico in the 1520s, killing 150,000 in
Tenochtitlán alone, including the emperor, and in
Peru
, image_flag = Flag of Peru.svg
, image_coat = Escudo nacional del Perú.svg
, other_symbol = Great Seal of the State
, other_symbol_type = Seal (emblem), National seal
, national_motto = "Fi ...
in the 1530s, aiding the European conquerors.
Measles killed a further two million native Mexicans in the 17th century. In 1618–1619, smallpox wiped out 90% of the
Massachusetts Bay Native Americans. During the 1770s, smallpox killed at least 30% of the
Pacific Northwest
The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...
Native Americans. Smallpox epidemics in
1780–1782 and
1837–1838 brought devastation and drastic depopulation among the
Plains Indians
Plains Indians or Indigenous peoples of the Great Plains and Canadian Prairies are the Native American tribes and First Nation band governments who have historically lived on the Interior Plains (the Great Plains and Canadian Prairies) o ...
. Some believe the death of up to 95% of the
Native American population of the
New World
The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. ...
was caused by Europeans introducing
Old World
The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by th ...
diseases such as smallpox, measles and influenza. Over the centuries, Europeans had developed high degrees of
herd immunity to these diseases, while the
indigenous peoples
Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...
had no such immunity.
Smallpox
Smallpox was an infectious disease caused by variola virus (often called smallpox virus) which belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) ce ...
, introduced by European settlers in 1789 to the
Australian continent, devastated the
Australian Aboriginal population, killing up to 50% of those infected with the disease during the first decades of colonisation. It also killed many New Zealand
Māori. In 1848–49, as many as 40,000 out of 150,000
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only ...
ans are estimated to have died of
measles,
whooping cough and
influenza
Influenza, commonly known as "the flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptom ...
. Introduced diseases, notably smallpox, nearly wiped out the native population of
Easter Island
Easter Island ( rap, Rapa Nui; es, Isla de Pascua) is an island and special territory of Chile in the southeastern Pacific Ocean, at the southeasternmost point of the Polynesian Triangle in Oceania. The island is most famous for its nearl ...
. Measles killed more than 40,000
Fijians, approximately one-third of the population, in 1875, and in the early 19th century devastated the
Great Andamanese population. The
Ainu
Ainu or Aynu may refer to:
*Ainu people, an East Asian ethnic group of Japan and the Russian Far East
*Ainu languages, a family of languages
**Ainu language of Hokkaido
**Kuril Ainu language, extinct language of the Kuril Islands
**Sakhalin Ainu la ...
population decreased drastically in the 19th century, due in large part to infectious diseases brought by Japanese settlers pouring into
Hokkaido
is Japan, Japan's Japanese archipelago, second largest island and comprises the largest and northernmost Prefectures of Japan, prefecture, making up its own List of regions of Japan, region. The Tsugaru Strait separates Hokkaidō from Honshu; th ...
.
Researchers concluded that
syphilis was carried from the New World to Europe after
Columbus
Columbus is a Latinized version of the Italian surname "''Colombo''". It most commonly refers to:
* Christopher Columbus (1451-1506), the Italian explorer
* Columbus, Ohio, capital of the U.S. state of Ohio
Columbus may also refer to:
Places ...
's voyages. The findings suggested Europeans could have carried the nonvenereal tropical bacteria home, where the organisms may have mutated into a more deadly form in the different conditions of Europe. The disease was more frequently fatal than it is today. Syphilis was a major killer in Europe during the
Renaissance
The Renaissance ( , ) , from , with the same meanings. is a period in European history marking the transition from the Middle Ages to modernity and covering the 15th and 16th centuries, characterized by an effort to revive and surpass id ...
. Between 1602 and 1796, the
Dutch East India Company sent almost a million Europeans to work in Asia. Ultimately, fewer than a third made their way back to Europe. The majority died of diseases. Disease killed more British soldiers in India and South Africa than war.
As early as 1803, the
Spanish Crown organized a mission (the
Balmis expedition) to transport the
smallpox vaccine to the
Spanish colonies
The Spanish Empire ( es, link=no, Imperio español), also known as the Hispanic Monarchy ( es, link=no, Monarquía Hispánica) or the Catholic Monarchy ( es, link=no, Monarquía Católica) was a colonial empire governed by Spain and its predec ...
, and establish mass vaccination programs there. By 1832, the federal government of the United States established a smallpox vaccination program for Native Americans. From the beginning of the 20th century onwards, the elimination or control of disease in tropical countries became a driving force for all
colonial
Colonial or The Colonial may refer to:
* Colonial, of, relating to, or characteristic of a colony or colony (biology)
Architecture
* American colonial architecture
* French Colonial
* Spanish Colonial architecture
Automobiles
* Colonial (1920 a ...
powers. The
sleeping sickness epidemic in Africa was arrested due to mobile teams systematically screening millions of people at risk. In the 20th century, the world saw the biggest increase in its
population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using ...
in human history due to a drop in the
mortality rate
Mortality rate, or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of d ...
in many countries as a result of
medical advances. The
world population
In demographics, the world population is the total number of humans currently living. It was estimated by the United Nations to have exceeded 8 billion in November 2022. It took over 200,000 years of human prehistory and human history, ...
has grown from 1.6 billion in 1900 to an estimated 6.8 billion in 2011.
Cholera
Since it became widespread in the 19th century, cholera has killed tens of millions of people.
*
1817–1824 cholera pandemic. Previously restricted to the
Indian subcontinent
The Indian subcontinent is a physiographical region in Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian Ocean from the Himalayas. Geopolitically, it includes the countries of Bangladesh, Bhutan, India ...
, the pandemic began in
Bengal
Bengal ( ; bn, বাংলা/বঙ্গ, translit=Bānglā/Bôngô, ) is a geopolitical, cultural and historical region in South Asia, specifically in the eastern part of the Indian subcontinent at the apex of the Bay of Bengal, predom ...
, then spread across India by 1820. 10,000 British troops and thousands of Indians died during this pandemic. It extended as far as China,
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
(where more than 100,000 people succumbed on the island of
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...
alone) and the
Caspian Sea
The Caspian Sea is the world's largest inland body of water, often described as the List of lakes by area, world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad s ...
before receding. Deaths in the Indian subcontinent between 1817 and 1860 are estimated to have exceeded 15 million. Another 23 million died between 1865 and 1917.
Russian deaths during a similar period exceeded 2million.
*
1826–1837 cholera pandemic. Reached Russia (see
Cholera Riots), Hungary (about 100,000 deaths) and Germany in 1831, London in 1832 (more than 55,000 persons died in the United Kingdom), France, Canada (
Ontario
Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...
), and United States (New York City) in the same year, and the Pacific coast of
North America by 1834. It is believed that more than 150,000 Americans died of cholera between 1832 and 1849.
[The 1832 Cholera Epidemic in New York State. p. 2]
By G. William Beardslee
*
1846–1860 cholera pandemic
The third cholera pandemic (1846–1860) was the third major outbreak of cholera originating in India in the nineteenth century that reached far beyond its borders, which researchers at UCLA believe may have started as early as 1837 and lasted ...
. Deeply affected Russia, with more than a million deaths. A two-year outbreak began in England and Wales in 1848 and claimed 52,000 lives. Throughout Spain, cholera caused more than 236,000 deaths in 1854–55. It claimed 200,000 lives in Mexico.
*
1863–1875 cholera pandemic
The fourth cholera pandemic of the 19th century began in the Ganges Delta of the Bengal region and traveled with Haj, Muslim pilgrims to Mecca. In its first year, the epidemic claimed 30,000 of 90,000 pilgrims. Cholera spread throughout the Middle ...
. Spread mostly in Europe and Africa. At least 30,000 of the 90,000
Mecca
Mecca (; officially Makkah al-Mukarramah, commonly shortened to Makkah ()) is a city and administrative center of the Mecca Province of Saudi Arabia, and the holiest city in Islam. It is inland from Jeddah on the Red Sea, in a narrow val ...
pilgrims were affected by the disease. Cholera killed 90,000 people in Russia in 1866.
* In 1866, there was an outbreak in North America. It killed some 50,000 Americans.
[
* 1881–1896 cholera pandemic. The 1883–1887 epidemic cost 250,000 lives in Europe and at least 50,000 in the Americas. Cholera claimed 267,890 lives in ]Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eigh ...
(1892); 120,000 in Spain; 90,000 in Japan and 60,000 in Persia
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkme ...
.
* In 1892, cholera contaminated the water supply of Hamburg
Hamburg (, ; nds, label=Hamburg German, Low Saxon, Hamborg ), officially the Free and Hanseatic City of Hamburg (german: Freie und Hansestadt Hamburg; nds, label=Low Saxon, Friee un Hansestadt Hamborg),. is the List of cities in Germany by popul ...
, and caused 8,606 deaths.
* 1899–1923 cholera pandemic
The sixth cholera pandemic (1899–1923) was a major outbreak of cholera beginning in India, where it killed more than 800,000 people, and spreading to the Middle East, North Africa, Eastern Europe and Russia.
History
According to Leonard Ro ...
. Had little effect in Europe because of advances in public health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals". Analyzing the det ...
, but Russia was badly affected again (more than 500,000 people dying of cholera during the first quarter of the 20th century). The sixth pandemic killed more than 800,000 in India. The 1902–1904 cholera epidemic claimed more than 200,000 lives in the Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
.
* Seventh cholera pandemic (1961–present). Began in Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
, called El Tor after the new biotype responsible for the pandemic, and reached Bangladesh
Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the List of countries and dependencies by population, eighth-most populous country in the world, with a population exceeding 165 million pe ...
in 1963, India in 1964, and the Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...
in 1966. The pandemic thereafter reached Africa in 1971 and the Americas in 1991. As of March 2022, the World Health Organization continues to define this outbreak as a current pandemic, noting that cholera has become endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...
in many countries. In 2017, WHO announced a global strategy aimed at this pandemic with the goal of reducing cholera deaths by 90% by 2030.
Dengue fever
Dengue is spread by several species of female mosquitoes of the Aedes type, principally ''A. aegypti''. The virus has five types; infection with one type usually gives lifelong immunity to that type, but only short-term immunity to the others. Subsequent infection with a different type increases the risk of severe complications. Several tests are available to confirm the diagnosis including detecting antibodies to the virus or its RNA.
Influenza
* The Greek physician Hippocrates
Hippocrates of Kos (; grc-gre, Ἱπποκράτης ὁ Κῷος, Hippokrátēs ho Kôios; ), also known as Hippocrates II, was a Greek physician of the classical period who is considered one of the most outstanding figures in the history o ...
, the "Father of Medicine", first described influenza in 412BC.
* The first influenza pandemic to be pathologically described occurred in 1510. Since the pandemic of 1580, influenza pandemics have occurred every 10 to 30 years.
* The 1889–1890 pandemic was attributed to influenza at the time but more recent research suggests it may have been caused by human coronavirus OC43. Also known as Russian Flu or Asiatic Flu, it was first reported in May 1889 in Bukhara
Bukhara (Uzbek language, Uzbek: /, ; tg, Бухоро, ) is the List of cities in Uzbekistan, seventh-largest city in Uzbekistan, with a population of 280,187 , and the capital of Bukhara Region.
People have inhabited the region around Bukhara ...
, Uzbekistan
Uzbekistan (, ; uz, Ozbekiston, italic=yes / , ; russian: Узбекистан), officially the Republic of Uzbekistan ( uz, Ozbekiston Respublikasi, italic=yes / ; russian: Республика Узбекистан), is a doubly landlocked co ...
. By October, it had reached Tomsk
Tomsk ( rus, Томск, p=tomsk, sty, Түң-тора) is a city and the administrative center of Tomsk Oblast in Russia, located on the Tom River. Population:
Founded in 1604, Tomsk is one of the oldest cities in Siberia. The city is a not ...
and the Caucasus
The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia (country), Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range ...
. It rapidly spread west and hit North America in December 1889, South America in February–April 1890, India in February–March 1890, and Australia in March–April 1890. The H3N8 and H2N2
Influenza A virus subtype H2N2 (A/H2N2) is a subtype of ''Influenza A virus''. H2N2 has mutated into various strains including the "Asian flu" strain (now extinct in the wild), H3N2, and various strains found in birds. It is also suspected of c ...
subtypes of the influenza A virus
'' A virus'' (''IAV'') causes influenza in birds and some mammals, and is the only species of the genus ''Alphainfluenzavirus'' of the virus family '' Orthomyxoviridae''. Strains of all subtypes of influenza A virus have been isolated from wil ...
have each been identified as possible causes. It had a very high attack and mortality rate
Mortality rate, or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of d ...
, causing around a million fatalities.
* The "Spanish flu
The 1918–1920 influenza pandemic, commonly known by the misnomer Spanish flu or as the Great Influenza epidemic, was an exceptionally deadly global influenza pandemic caused by the H1N1 influenza A virus. The earliest documented case wa ...
", 1918–1920. First identified early in March 1918 in U.S. troops training at Camp Funston, Kansas
Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to ...
. By October 1918, it had spread to become a worldwide pandemic on all continents, and eventually infected about one-third of the world's population
In demographics, the world population is the total number of humans currently living. It was estimated by the United Nations to have exceeded 8 billion in November 2022. It took over 200,000 years of human prehistory and history for the ...
(or ≈500 million persons). Unusually deadly and virulent, it persisted in pandemic form for at least two years before settling into more endemic patterns. Within six months, some 50million people were dead; some estimates put the total number of fatalities worldwide at over twice that number. About 17million died in India, 675,000 in the United States, and 200,000 in the United Kingdom. The virus that caused Spanish flu was also implicated as a cause of encephalitis lethargica
Encephalitis lethargica is an atypical form of encephalitis. Also known as "sleeping sickness" or "sleepy sickness" (distinct from tsetse fly-transmitted sleeping sickness), it was first described in 1917 by neurologist Constantin von Econom ...
in children. The virus was recently reconstructed by scientists at the CDC studying remains preserved by the Alaskan permafrost
Permafrost is ground that continuously remains below 0 °C (32 °F) for two or more years, located on land or under the ocean. Most common in the Northern Hemisphere, around 15% of the Northern Hemisphere or 11% of the global surfac ...
. The 2009 pandemic H1N1 virus has a small but crucial structure that is similar to the Spanish flu.
* The " Asian flu", 1957–58. An H2N2
Influenza A virus subtype H2N2 (A/H2N2) is a subtype of ''Influenza A virus''. H2N2 has mutated into various strains including the "Asian flu" strain (now extinct in the wild), H3N2, and various strains found in birds. It is also suspected of c ...
virus was first identified in China in late February 1957 but not recognized globally until after an outbreak in Hong Kong
Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China (abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delta i ...
in April. From there, it spread throughout Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...
and the greater continent during the spring and throughout the Southern Hemisphere during the middle months of the year, causing extensive outbreaks. By the end of September, nearly the entire inhabited world had been infected or at least seeded with the virus. The Northern Hemisphere experienced widespread outbreaks during the fall and winter, and some parts of the world saw a second wave during this time or in early 1958. The pandemic caused about two million deaths globally.
* The "Hong Kong flu
The Hong Kong flu, also known as the 1968 flu pandemic, was a flu pandemic whose outbreak in 1968 and 1969 killed between one and four million people globally. It is among the deadliest pandemics in history, and was caused by an H3N2 strain of ...
", 1968–70. An H3N2 virus was first detected in Hong Kong in July 1968 and spread across the world, lasting until 1970. This pandemic exhibited a more "smoldering" pattern as compared with other influenza pandemics, with uneven impact in different places over time. Its course at first resembled that of the 1957 pandemic, but after a couple of months its spread faltered; the virus did not immediately result in extensive outbreaks in some places, despite repeated introductions. The United States notably experienced an intense epidemic during the 1968–1969 flu season, the first with the pandemic virus, while European and Asian countries were relatively less affected. During the 1969–1970 season, however, the United States was much less affected, while Europe and Asia experienced extensive outbreaks of the pandemic virus. In the Southern Hemisphere, Australia experienced a pattern more akin to Europe and Asia, with a more severe second wave. This pandemic killed approximately one million people worldwide.
* The " 1977 Russian flu", 1977–79. An H1N1 virus was first reported by the Soviet Union in 1977. The pandemic caused an estimated 700,000 deaths worldwide and mostly affected the younger population.
* The " Swine flu", 2009–10. An H1N1 virus first detected in Mexico in early 2009. Estimates for the mortality of this pandemic range from 150 to 500 thousand.
Typhus
Typhus
Typhus, also known as typhus fever, is a group of infectious diseases that include epidemic typhus, scrub typhus, and murine typhus. Common symptoms include fever, headache, and a rash. Typically these begin one to two weeks after exposure. ...
is sometimes called "camp fever" because of its pattern of flaring up in times of strife. (It is also known as "gaol fever", "Aryotitus fever" and "ship fever", for its habits of spreading wildly in cramped quarters, such as jails and ships.) Emerging during the Crusades
The Crusades were a series of religious wars initiated, supported, and sometimes directed by the Latin Church in the medieval period. The best known of these Crusades are those to the Holy Land in the period between 1095 and 1291 that were ...
, it had its first impact in Europe in 1489, in Spain. During fighting between the Christian Spaniards and the Muslims in Granada
Granada (,, DIN: ; grc, Ἐλιβύργη, Elibýrgē; la, Illiberis or . ) is the capital city of the province of Granada, in the autonomous community of Andalusia, Spain. Granada is located at the foot of the Sierra Nevada mountains, at the c ...
, the Spanish lost 3,000 to war casualties, and 20,000 to typhus. In 1528, the French lost 18,000 troops in Italy, and lost supremacy in Italy to the Spanish. In 1542, 30,000 soldiers died of typhus while fighting the Ottomans in the Balkans.
During the Thirty Years' War
The Thirty Years' War was one of the longest and most destructive conflicts in European history, lasting from 1618 to 1648. Fought primarily in Central Europe, an estimated 4.5 to 8 million soldiers and civilians died as a result of battl ...
(1618–1648), about eight million Germans were killed by bubonic plague and typhus. The disease also played a major role in the destruction of Napoleon's ''Grande Armée
''La Grande Armée'' (; ) was the main military component of the French Imperial Army commanded by Emperor Napoleon Bonaparte during the Napoleonic Wars. From 1804 to 1808, it won a series of military victories that allowed the French Empi ...
'' in Russia in 1812. During the retreat from Moscow, more French military personnel died of typhus
Typhus, also known as typhus fever, is a group of infectious diseases that include epidemic typhus, scrub typhus, and murine typhus. Common symptoms include fever, headache, and a rash. Typically these begin one to two weeks after exposure. ...
than were killed by the Russians. Of the 450,000 soldiers who crossed the Neman on 25 June 1812, fewer than 40,000 returned. More military personnel were killed from 1500 to 1914 by typhus than from military action.[War and Pestilence](_blank)
''Time''. In early 1813, Napoleon raised a new army of 500,000 to replace his Russian losses. In the campaign of that year, more than 219,000 of Napoleon's soldiers died of typhus.[ Typhus played a major factor in the Great Famine of Ireland. During ]World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...
, typhus epidemics killed more than 150,000 in Serbia
Serbia (, ; Serbian: , , ), officially the Republic of Serbia (Serbian: , , ), is a landlocked country in Southeastern and Central Europe, situated at the crossroads of the Pannonian Basin and the Balkans. It shares land borders with Hung ...
. There were about 25 million infections and 3million deaths from epidemic typhus in Russia from 1918 to 1922. Typhus also killed numerous prisoners in the Nazi concentration camps
From 1933 to 1945, Nazi Germany operated more than a thousand concentration camps, (officially) or (more commonly). The Nazi concentration camps are distinguished from other types of Nazi camps such as forced-labor camps, as well as concen ...
and Soviet prisoner of war camps during World WarII. More than 3.5 million Soviet POWs died out of the 5.7 million in Nazi custody.
Smallpox
Smallpox
Smallpox was an infectious disease caused by variola virus (often called smallpox virus) which belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) ce ...
was a contagious disease caused by the variola virus. The disease killed an estimated 400,000 Europeans per year during the closing years of the 18th century. During the 20th century, it is estimated that smallpox was responsible for 300–500 million deaths. As recently as the early 1950s, an estimated 50 million cases of smallpox occurred in the world each year. After successful vaccination campaigns throughout the 19th and 20th centuries, the WHO certified the eradication of smallpox in December 1979. To this day, smallpox is the only human infectious disease to have been completely eradicated, and one of two infectious viruses ever to be eradicated, along with rinderpest
Rinderpest (also cattle plague or steppe murrain) was an infectious viral disease of cattle, domestic buffalo, and many other species of even-toed ungulates, including gaurs, buffaloes, large antelope, deer, giraffes, wildebeests, and w ...
.
Measles
Historically, measles was prevalent throughout the world, as it is highly contagious. According to the U.S. National Immunization Program
The National Center for Immunization and Respiratory Diseases (NCIRD), formerly known as the National Immunization Program until April 2006, is charged with responsibility for the planning, coordination, and conduct of immunization activities in ...
, by 1962 90% of people were infected with measles by age 15. Before the vaccine was introduced in 1963, there were an estimated three to four million cases in the U.S. each year.[Center for Disease Control & National Immunization Program. Measles History, article online 2001. Available from https://www.cdc.gov/measles/about/history.html] Measles killed around 200 million people worldwide over the last 150 years.[ In 2000 alone, measles killed some 777,000 worldwide out of 40 million cases globally.
Measles is an endemic disease, meaning it has been continually present in a community, and many people develop resistance. In populations that have not been exposed to measles, exposure to a new disease can be devastating. In 1529, a measles outbreak in ]Cuba
Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribbea ...
killed two-thirds of the natives who had previously survived smallpox. The disease had ravaged Mexico, Central America
Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...
, and the Inca civilization.
Tuberculosis
One-quarter of the world's current population has been infected with '' Mycobacterium tuberculosis'', and new infections occur at a rate of one per second.World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level o ...
(WHO)
Tuberculosis Fact sheet No. 104—Global and regional incidence.
March 2006, Retrieved on 6 October 2006. About 5–10% of these latent infections will eventually progress to active disease, which, if left untreated, kills more than half its victims. Annually, eight million people become ill with tuberculosis, and two million die from the disease worldwide.[ Centers for Disease Control]
Fact Sheet: Tuberculosis in the United States.
17 March 2005, Retrieved on 6 October 2006. In the 19th century, tuberculosis killed an estimated one-quarter of the adult population of Europe; by 1918, one in six deaths in France were still caused by tuberculosis. During the 20th century, tuberculosis killed approximately 100 million people. TB is still one of the most important health problems in the developing world. In 2018, Tuberculosis became the leading cause of death from an infectious disease, with roughly 1.5 million deaths worldwide.
Leprosy
Leprosy, also known as Hansen's disease, is caused by a bacillus, '' Mycobacterium leprae''. It is a chronic disease with an incubation period of up to five years. Since 1985, 15 million people worldwide have been cured of leprosy.
Historically, leprosy has affected people since at least 600 BC. Leprosy outbreaks began to occur in Western Europe around 1000 AD. Numerous ''leprosoria'', or leper hospitals
Leprosy, also known as Hansen's disease (HD), is a long-term infection by the bacteria ''Mycobacterium leprae'' or ''Mycobacterium lepromatosis''. Infection can lead to damage of the nerves, respiratory tract, skin, and eyes. This nerve damage ...
, sprang up in the Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...
; Matthew Paris estimated that in the early 13th century, there were 19,000 of them across Europe.
Malaria
Malaria
Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or deat ...
is widespread in tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
and subtropical regions, including parts of the Americas, Asia, and Africa. Each year, there are approximately 350–500 million cases of malaria. Drug resistance
Drug resistance is the reduction in effectiveness of a medication such as an antimicrobial or an antineoplastic in treating a disease or condition. The term is used in the context of resistance that pathogens or cancers have "acquired", that is, ...
poses a growing problem in the treatment of malaria in the 21st century, since resistance is now common against all classes of antimalarial drugs, except for the artemisinins.
Malaria was once common in most of Europe and North America, where it is now for all purposes non-existent. Malaria may have contributed to the decline of the Roman Empire
The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post- Republican period of ancient Rome. As a polity, it included large territorial holdings around the Medite ...
. The disease became known as " Roman fever". '' Plasmodium falciparum'' became a real threat to colonists and indigenous people
Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...
alike when it was introduced into the Americas along with the slave trade. Malaria devastated the Jamestown colony and regularly ravaged the South and Midwest of the United States. By 1830, it had reached the Pacific Northwest. During the American Civil War
The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by state ...
, there were more than 1.2 million cases of malaria among
soldiers of both sides. The southern U.S. continued to be affected by millions of cases of malaria into the 1930s.
Yellow fever
Yellow fever
Yellow fever is a viral disease of typically short duration. In most cases, symptoms include fever, chills, loss of appetite, nausea, muscle pains – particularly in the back – and headaches. Symptoms typically improve within five days. In ...
has been a source of several devastating epidemics. Cities as far north as New York, Philadelphia, and Boston were hit with epidemics. In 1793, one of the largest yellow fever epidemics in U.S. history killed as many as 5,000 people in Philadelphia—roughly 10% of the population. About half of the residents had fled the city, including President George Washington.
Another major outbreak of the disease struck the Mississippi River Valley in 1878, with deaths estimated at 20,000. Among the hardest-hit places was Memphis, Tennessee, where 5,000 people were killed and over 20,000 fled, then representing over half the city's population, many of whom never returned. In colonial times, West Africa became known as "the white man's grave" because of malaria and yellow fever.
Concerns about future pandemics
In a press conference on 28 December 2020, Dr. Mike Ryan, head of the WHO Emergencies Program, and other officials said the current COVID-19 pandemic is "not necessarily the big one" and "the next pandemic may be more severe." They called for preparation. The WHO and the UN, have warned the world must tackle the cause of pandemics and not just the health and economic symptoms.
The October 2020 'era of pandemics' report by the United Nations
The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a centre for harmonizi ...
' Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, written by 22 experts in a variety of fields, said the anthropogenic destruction of biodiversity
Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic ('' genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity' ...
is paving the way to the pandemic era and could result in as many as 850,000 viruses being transmitted from animals—in particular birds
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
and mammals
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fu ...
—to humans. The "exponential rise" in consumption and trade of commodities such as meat, palm oil
Palm oil is an edible vegetable oil derived from the mesocarp (reddish pulp) of the fruit of the oil palms. The oil is used in food manufacturing, in beauty products, and as biofuel. Palm oil accounted for about 33% of global oils produced fr ...
, and metals, largely facilitated by developed nations, and a growing human population, are the primary drivers of this destruction. According to Peter Daszak
Peter Daszak is a British zoologist, consultant and public expert on disease ecology, in particular on zoonosis. He is the president of EcoHealth Alliance, a nonprofit non-governmental organization that supports various programs on global healt ...
, the chair of the group who produced the report, "there is no great mystery about the cause of the Covid-19 pandemic or any modern pandemic. The same human activities that drive climate change and biodiversity loss
Climate change has adversely affected both terrestrial and marine ecosystems, and is expected to further affect many ecosystems, including tundra, mangroves, coral reefs, caves etc. Increasing global temperature, more frequent occurrence ...
also drive pandemic risk through their impacts on our environment." Proposed policy options from the report include taxing meat production and consumption, cracking down on the illegal wildlife trade, removing high-risk species from the legal wildlife trade, eliminating subsidies to businesses that are harmful to the natural world, and establishing a global surveillance network.
In June 2021, a team of scientists assembled by the warned that the primary cause of pandemics so far, the anthropogenic destruction of the natural world through such activities including deforestation
Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then land conversion, converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban area, urban ...
and hunting
Hunting is the human practice of seeking, pursuing, capturing, or killing wildlife or feral animals. The most common reasons for humans to hunt are to harvest food (i.e. meat) and useful animal products ( fur/ hide, bone/ tusks, horn/ a ...
, is being ignored by world leaders.
Antibiotic resistance
Antibiotic-resistant microorganisms, which sometimes are referred to as " superbugs", may contribute to the re-emergence of diseases that are currently well controlled. For example, cases of tuberculosis that are resistant to traditionally effective treatments remain a cause of great concern to health professionals. Every year, nearly half a million new cases of multidrug-resistant tuberculosis (MDR-TB) are estimated to occur worldwide. China and India have the highest rate of multidrug-resistant TB. The World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level o ...
(WHO) reports that approximately 50 million people worldwide are infected with MDR TB, with 79 percent of those cases resistant to three or more antibiotics. In 2005, 124 cases of MDR TB were reported in the United States. Extensively drug-resistant tuberculosis ( XDR TB) was identified in Africa in 2006 and subsequently discovered to exist in 49 countries, including the United States. There are about 40,000 new cases of XDR-TB per year, the WHO estimates.
In the past 20 years, common bacteria including ''Staphylococcus aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often posit ...
'', '' Serratia marcescens'' and Enterococcus, have developed resistance to various antibiotics
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ...
such as vancomycin, as well as whole classes of antibiotics, such as the aminoglycosides and cephalosporins. Antibiotic-resistant organisms have become an important cause of healthcare-associated (nosocomial) infections (HAI). In addition, infections caused by community-acquired strains of methicillin-resistant ''Staphylococcus aureus'' ( MRSA) in otherwise healthy individuals have become more frequent in recent years.
Pandemic preparedness
Early development of vaccines may be one way to prepare for future pandemics that couldn't get prevented. In 2021, scientists called for accelerated efforts in the development of broadly protective vaccines, especially a universal coronavirus vaccine that durably protects not just against all SARS-CoV-2 variants but also other coronaviruses, including already identified animal coronaviruses with pandemic potential. Other components may include measures related to disease surveillance for detecting pathogens (including early warning systems), data collection and modelling to enable tracing and explaining the spread of pathogens, improvements to public-health guidance and communication, and the development of relevant therapies, including therapies beyond vaccines.
Climate change
Overpopulation
Encroaching into wildlands
Concerning diseases
Viral hemorrhagic fevers
Viral hemorrhagic fevers such as Ebola virus disease, Lassa fever, Rift Valley fever, Marburg virus disease, Severe fever with thrombocytopenia as well as Argentine, Bolivian, Brazilian, Crimean-Congo and Venezuelan hemorrhagic fevers are highly contagious and deadly diseases, with the theoretical potential to become pandemics. Their ability to spread efficiently enough to cause a pandemic is limited, however, as transmission of these viruses requires close contact with the infected vector, and the vector has only a short time before death or serious illness. Furthermore, the short time between a vector becoming infectious and the onset of symptoms allows medical professionals to quickly quarantine
A quarantine is a restriction on the movement of people, animals and goods which is intended to prevent the spread of disease or pests. It is often used in connection to disease and illness, preventing the movement of those who may have been ...
vectors, and prevent them from carrying the pathogen elsewhere. Genetic mutations could occur, which could elevate their potential for causing widespread harm; thus close observation by contagious disease specialists is merited.
Coronaviruses
Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East respiratory syndrome (MERS-CoV) and severe acute respiratory syndrome (SARS-CoV-1). A new strain of coronavirus (SARS-CoV-2) causes Coronavirus disease 2019
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease quickly ...
, or COVID-19, which was declared as a pandemic by the WHO on 11 March 2020.
Some coronaviruses are zoonotic, meaning they are transmitted between animals and people. Detailed investigations found that SARS-CoV-1 was transmitted from civet cats to humans and MERS-CoV from dromedary camels to humans. Several known coronaviruses are circulating in animals that have not yet infected humans. Common signs of infection include respiratory symptoms, fever
Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...
, cough
A cough is a sudden expulsion of air through the large breathing passages that can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three ph ...
, shortness of breath, and breathing difficulties. In more severe cases, an infection can cause pneumonia, acute respiratory distress syndrome
Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin col ...
, kidney failure, and even death. Standard recommendations to prevent the spread of infection include regular hand washing, wearing a face mask, going outdoors when meeting people, and avoiding close contact with people who have tested positive regardless of whether they have symptoms or not. It is recommended that people stay two meters or six feet away from others, commonly called social distancing.
= Severe acute respiratory syndrome
=
After the SARS outbreak, in 2003 the Italian physician Carlo Urbani (1956–2003) was the first to identify severe acute respiratory syndrome (SARS
Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the severe acute respiratory syndrome coronavirus (SARS-CoV or SARS-CoV-1), the first identified strain of the SARS coronavirus species, '' s ...
) as a new and dangerously contagious disease, although he became infected and died. It is caused by a coronavirus dubbed SARS-CoV-1. Rapid action by national and international health authorities such as the World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level o ...
helped to slow transmission and eventually broke the chain of transmission, which ended the localized epidemics before they could become a pandemic. However, the disease has not been eradicated and could re-emerge. This warrants monitoring and reporting of suspicious cases of atypical pneumonia.
Influenza
Wild aquatic birds are the natural hosts for a range of influenza A viruses. Occasionally, viruses are transmitted from these species to other species, and may then cause outbreaks in domestic poultry or, rarely, in humans.
= H5N1 (Avian flu)
=
In February 2004, avian influenza virus was detected in birds in Vietnam
Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making it ...
, increasing fears of the emergence of new variant strains. It is feared that if the avian influenza virus combines with a human influenza virus (in a bird or a human), the new subtype created could be both highly contagious and highly lethal in humans. Such a subtype could cause a global influenza pandemic, similar to the Spanish flu
The 1918–1920 influenza pandemic, commonly known by the misnomer Spanish flu or as the Great Influenza epidemic, was an exceptionally deadly global influenza pandemic caused by the H1N1 influenza A virus. The earliest documented case wa ...
or the lower mortality pandemics such as the Asian flu and the Hong Kong flu.
From October 2004 to February 2005, some 3,700 test kits of the 1957 pandemic influenza virus, H2N2, were accidentally spread around the world from a lab in the U.S.
In May 2005, scientists urgently called upon nations to prepare for a global influenza pandemic that could strike as much as 20% of the world's population.
In October 2005, cases of the avian flu (the deadly strain H5N1) were identified in Turkey. EU Health Commissioner Markos Kyprianou said: "We have received now confirmation that the virus found in Turkey is an avian flu H5N1 virus. There is a direct relationship with viruses found in Russia, Mongolia, and China." Cases of bird flu were also identified shortly thereafter in Romania, and then Greece. Possible cases of the virus have also been found in Croatia, Bulgaria, and the United Kingdom.
By November 2007, numerous confirmed cases of the H5N1 strain had been identified across Europe. However, by the end of October, only 59 people had died as a result of H5N1, which was atypical of previous influenza pandemics.
Avian flu cannot be categorized as a "pandemic" because the virus cannot yet cause sustained and efficient human-to-human transmission. Cases so far are recognized to have been transmitted from bird to human, but as of December 2006 there had been few (if any) cases of proven human-to-human transmission. Regular influenza viruses establish infection by attaching to receptors in the throat and lungs, but the avian influenza virus can attach only to receptors located deep in the lungs of humans, requiring close, prolonged contact with infected patients, and thus limiting person-to-person transmission.
Zika virus
An outbreak of Zika virus
''Zika virus'' (ZIKV; pronounced or ) is a member of the virus family '' Flaviviridae''. It is spread by daytime-active '' Aedes'' mosquitoes, such as ''A. aegypti'' and ''A. albopictus''. Its name comes from the Ziika Forest of Uganda, wh ...
began in 2015 and strongly intensified throughout the start of 2016, with more than 1.5 million cases across more than a dozen countries in the Americas
The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World.
Along with th ...
. The World Health Organization warned that Zika had the potential to become an explosive global pandemic if the outbreak was not controlled.
Economic consequences
In 2016, the commission on a Global Health Risk Framework for the Future estimated that pandemic disease events would cost the global economy over $6 trillion in the 21st century—over $60 billion per year. The same report recommended spending $4.5 billion annually on global prevention and response capabilities to reduce the threat posed by pandemic events, a figure that the World Bank Group raised to $13 billion in a 2019 report. It has been suggested that such costs be paid from a tax on aviation rather than from, e.g., income taxes, given the crucial role of air traffic in transforming local epidemics into pandemics (being the only factor considered in state-of-the-art models of long-range disease transmission ).
The COVID-19 pandemic is expected to have a profound negative effect on the global economy, potentially for years to come, with substantial drops in GDP accompanied by increases in unemployment noted around the world. The slowdown of economic activity early in the COVID-19 pandemic had a profound effect on emissions of pollutants and greenhouse gases. The reduction of air pollution, and economic activity associated with it during a pandemic was first documented by Alexander F. More for the Black Death plague pandemic, showing the lowest pollution levels in the last 2000 years occurring during that pandemic, due to its 40 to 60% death rate throughout Eurasia.
See also
* Asian Flu of 1957
* Biological hazard
* Compartmental models in epidemiology
* Crowdmapping Crowdmapping is a subtype of crowdsourcing by which aggregation of crowd-generated inputs such as captured communications and social media feeds are combined with geographic data to create a digital map that is as up-to-date as possible on events ...
* Disease X
* European Centre for Disease Prevention and Control (ECDC)
* Hong Kong Flu
The Hong Kong flu, also known as the 1968 flu pandemic, was a flu pandemic whose outbreak in 1968 and 1969 killed between one and four million people globally. It is among the deadliest pandemics in history, and was caused by an H3N2 strain of ...
of 1968
* Immunization
Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an infectious agent (known as the immunogen).
When this system is exposed to molecules that are foreign to the body, called ''non-s ...
* Mathematical modelling of infectious disease
* Medieval demography
* Mortality from infectious diseases
* Pandemic fatigue
* Pandemic severity index
* Public health emergency of international concern
A public health emergency of international concern (PHEIC) is a formal declaration by the World Health Organization (WHO) of "an extraordinary event which is determined to constitute a public health risk to other States through the internatio ...
* Super-spreader
* Syndemic
* Tropical disease
* Timeline of global health
* Twindemic
Twindemic and tripledemic (or tridemic) are terms used during the COVID-19 pandemic, referring to the possibility of a severe flu season happening alongside an increase in cases of COVID-19 during the fall and winter of 2020 and 2021, as well as ...
* Vaccination
* WHO pandemic phases
Notes
References
Further reading
*
*
* Brook, Timothy; et al. "Comparative pandemics: the Tudor–Stuart and Wanli–Chongzhen years of pestilence, 1567–1666" ''Journal of Global History'' (2020) 14#3 pp 363–379 emphasis on Chinese history, compared to England
* Eisenberg, Merle, and Lee Mordechai. "The Justinianic Plague and Global Pandemics: The Making of the Plague Concept." ''American Historical Review'' 125.5 (2020): 1632–1667.
*
*
*
* McKenna, Maryn, "Return of the Germs: For more than a century drugs and vaccines made astounding progress against infectious diseases. Now our best defenses may be social changes", ''Scientific American
''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it i ...
'', vol. 323, no. 3 (September 2020), pp. 50–56. "What might prevent or lessen hepossibility f a virus emerging and finding a favorable human hostis more prosperity more equally distributed – enough that villagers in South Asia need not trap and sell bats to supplement their incomes and that, low-wage workers in the U.S. need not go to work while ill because they have no sick leave." (p. 56.)
* Quammen, David, "The Sobbing Pangolin: How a threatened animal may be linked to the ovid-19pandemic's beginnings", ''The New Yorker
''The New Yorker'' is an American weekly magazine featuring journalism, commentary, criticism, essays, fiction, satire, cartoons, and poetry. Founded as a weekly in 1925, the magazine is published 47 times annually, with five of these issue ...
'', 31 August 2020, pp. 26–31. "More field research is needed .. More sampling of wild animals. More scrutiny of genomes. More cognizance of the fact that animal infections can become human infections because humans are animals. We live in a world of viruses, and we have scarcely begun to understand this one COVID-19 ">COVID-19.html" ;"title="COVID-19">COVID-19 (p. 31.)
*
External links
WHO , World Health Organization
Past pandemics that ravaged Europe
Pandemic Influenza
at CDC
European Centre for Disease Prevention and Control
TED-Education videoHow pandemics spread
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Biological hazards
Doomsday scenarios
Economic problems
Future problems
Global health
Health disasters
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