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Friday, February 15, 2019

Pandemic

From Wikipedia, the free encyclopedia

The 1918–1919 "Spanish flu" pandemic resulted in dramatic mortality worldwide.
 
A pandemic is an epidemic of disease that has spread across a large region; for instance multiple continents, or even worldwide. This may include communicable and noncommunicable diseases

A widespread endemic disease that is stable in terms of how many people are getting sick from it is not a pandemic. Further, flu pandemics generally exclude recurrences of seasonal flu. Throughout history, there have been a number of pandemics, such as smallpox and tuberculosis. One of the most devastating pandemics was the Black Death, which killed over 75 million people in 1350. The most recent pandemics include the HIV pandemic as well as the 1918 and 2009 H1N1 pandemics.

Definition and stages

Advice (in French and English) for travelers on risks of epidemics abroad. Posters from the Charles De Gaulle airport, Paris, 2016.
 
A pandemic is an epidemic occurring on a scale which crosses international boundaries, usually affecting a large number of people. Pandemics can also occur in important agricultural organisms (livestock, crop plants, fish, tree species) or in other organisms. 

The World Health Organization (WHO) has a six-stage classification that describes the process by which a novel influenza virus moves from the first few infections in humans through to a pandemic. This starts with the virus mostly infecting animals, with a few cases where animals infect people, then moves through the stage where the virus begins to spread directly between people, and ends with a pandemic when infections from the new virus have spread worldwide and it will be out of control until we stop it.

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 is responsible for many deaths but is not considered a pandemic because the disease is not infectious or contagious.

In a virtual press conference in May 2009 on the 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 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, revised in 2005 and in February 2009, defining phases and appropriate actions for each phase in an aide memoir entitled WHO pandemic phase descriptions and main actions by phase. The 2009 revision, including definitions of a pandemic and the phases leading to its declaration, were finalized in February 2009. The pandemic H1N1 2009 virus 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 and mortality are not mentioned in the current WHO definition, although these factors have previously been included.

Current pandemics

HIV and AIDS

HIV originated in Africa, and spread to the United States via Haiti between 1966 and 1972. AIDS is currently a pandemic, with infection rates as high as 25% in southern and eastern Africa. In 2006, the HIV prevalence rate among pregnant women in South Africa was 29.1%. 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. Infection rates are rising again in Asia and the Americas. The AIDS death toll in Africa may reach 90–100 million by 2025.

Pandemics and notable epidemics through history

There have been a number of significant pandemics recorded in human history, generally zoonoses which came about with domestication of animals, such as influenza and tuberculosis. There have been a number of particularly significant epidemics that deserve mention above the "mere" destruction of cities:
  • Plague of Athens, 430 BC. Possibly typhoid fever killed a quarter of the Athenian troops, and a quarter of the population over four years. This disease fatally weakened the dominance of Athens, 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 recovered from a mass grave underneath the city, and confirmed the presence of bacteria responsible for typhoid.
Bubonic plague victims in a mass grave from 1720–1721 in Martigues, France
  • Antonine Plague, 165–180 AD. Possibly smallpox brought to the Italian peninsula by soldiers returning from the Near East; it killed a quarter of those infected, and up to five million in all. At the height of a second outbreak, the Plague of Cyprian (251–266), which may have been the same disease, 5,000 people a day were said to be dying in Rome.
  • Plague of Justinian, from 541 to 750, was the first recorded outbreak of the bubonic plague. It started in Egypt, and reached Constantinople the following spring, killing (according to the Byzantine chronicler Procopius) 10,000 a day at its height, and perhaps 40% of the city's inhabitants. The plague went on to eliminate a quarter to a half of the human population that it struck throughout the known world. It caused Europe's population to drop by around 50% between 550 and 700.
  • Black Death, from 1331 to 1353. The total number of deaths worldwide is estimated at 75 million people. Eight hundred years after the last outbreak, the plague returned to Europe. Starting in Asia, the disease reached Mediterranean and western Europe in 1348 (possibly from Italian merchants fleeing fighting in Crimea), 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 in 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 of 1665–66 was the last major outbreak of the plague in England. The disease killed approximately 100,000 people, 20% of London's population.
  • The third plague pandemic started in China in 1855, and spread to India, where 10 million people died. During this pandemic, the United States saw its first outbreak: the San Francisco plague of 1900–1904. Today, isolated cases of plague are still found in the western United States.
Aztecs dying of smallpox, Florentine Codex (compiled 1540–1585)
 
Encounters between European explorers and populations in the rest of the world often introduced local epidemics of extraordinary virulence. Disease killed part of the native population of the Canary Islands in the 16th century (Guanches). Half the native population of Hispaniola in 1518 was killed by smallpox. Smallpox also ravaged Mexico in the 1520s, killing 150,000 in Tenochtitlán alone, including the emperor, and Peru in the 1530s, aiding the European conquerors. Measles killed a further two million Mexican natives 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 Native Americans. Smallpox epidemics in 1780–1782 and 1837–1838 brought devastation and drastic depopulation among the Plains Indians. Some believe that the death of up to 95% of the Native American population of the New World was caused by Old World diseases such as smallpox, measles, and influenza. Over the centuries, the Europeans had developed high degrees of immunity to these diseases, while the indigenous peoples had no such immunity.

Smallpox devastated the native population of Australia, killing around 50% of Indigenous Australians in the early years of British colonization. It also killed many New Zealand Māori. As late as 1848–49, as many as 40,000 out of 150,000 Hawaiians are estimated to have died of measles, whooping cough and influenza. Introduced diseases, notably smallpox, nearly wiped out the native population of Easter Island. In 1875, measles killed over 40,000 Fijians, approximately one-third of the population. The disease devastated the Andamanese population. Ainu population decreased drastically in the 19th century, due in large part to infectious diseases brought by Japanese settlers pouring into Hokkaido.

Researchers concluded that syphilis was carried from the New World to Europe after Columbus' 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. Between 1602 and 1796, the Dutch East India Company sent almost a million Europeans to work in Asia. Ultimately, only less than one-third made their way back to Europe. The majority died of diseases. Disease killed more British soldiers in India than war.

As early as 1803, the Spanish Crown organized a mission (the Balmis expedition) to transport the smallpox vaccine to the Spanish colonies, 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 onward, the elimination or control of disease in tropical countries became a driving force for all colonial 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 in human history due to lessening of the mortality rate in many countries due to medical advances. The world population has grown from 1.6 billion in 1900 to an estimated 7 billion today.

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 pandemic began in Bengal, then spread across India by 1820. 10,000 British troops and countless Indians died during this pandemic. It extended as far as China, Indonesia (where more than 100,000 people succumbed on the island of Java alone) and the Caspian Sea before receding. Deaths in the Indian subcontinent between 1817 and 1860 are estimated to have exceeded 15 million persons. Another 23 million died between 1865 and 1917. Russian deaths during a similar period exceeded 2 million.
  • 1826–1837 cholera pandemic. Reached Russia, 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), and United States (New York City) in the same year, and the Pacific coast of North America by 1834. It is believed that over 150,000 Americans died of cholera between 1832 and 1849.
  • 1846–1860 cholera pandemic. Deeply affected Russia, with over 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.
  • 1863–75 cholera pandemic. Spread mostly in Europe and Africa. At least 30,000 of the 90,000 Mecca pilgrims fell victim to the disease. Cholera claimed 90,000 lives in Russia in 1866.
  • In 1866, there was an outbreak in North America. It killed some 50,000 Americans.
  • 1881–96 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 (1892); 120,000 in Spain; 90,000 in Japan and 60,000 in Persia.
  • In 1892, cholera contaminated the water supply of Hamburg, and caused 8,606 deaths.
  • 1899–1923 cholera pandemic. Had little effect in Europe because of advances in public health, 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 over 200,000 lives in the Philippines.
  • 1961–75 cholera pandemic. Began in Indonesia, called El Tor after the new biotype responsible for the pandemic, and reached Bangladesh in 1963, India in 1964, and the USSR in 1966. Since then the pandemic has reached Africa, South America, and central America.

Influenza

World Health Organization influenza pandemic alert phases
  • The Greek physician Hippocrates, the "Father of Medicine", first described influenza in 412 BC.
  • The first influenza pandemic was recorded in 1580, and since then, influenza pandemics occurred every 10 to 30 years.
  • The 1889–1890 flu pandemic, also known as Russian Flu, was first reported in May 1889 in Bukhara, Uzbekistan. By October, it had reached Tomsk and the Caucasus. 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 subtypes of the Influenza A virus have each been identified as possible causes. It had a very high attack and mortality rate, causing around a million fatalities.
  • The "Spanish flu", 1918–1919. First identified early in March 1918 in US troops training at Camp Funston, Kansas. 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 (or ≈ 500 million persons). Unusually deadly and virulent, it ended nearly as quickly as it began, vanishing completely within 18 months. In six months, some 50 million were dead; some estimates put the total of those killed worldwide at over twice that number. About 17 million died in India, 675,000 in the United States and 200,000 in the UK. The virus was recently reconstructed by scientists at the CDC studying remains preserved by the Alaskan permafrost. The H1N1 virus has a small, but crucial structure that is similar to the Spanish Flu.
  • The "Asian Flu", 1957–58. An H2N2 virus caused about 70,000 deaths in the United States. First identified in China in late February 1957, the Asian flu spread to the United States by June 1957. It caused about 2 million deaths globally.
  • The "Hong Kong Flu", 1968–69. An H3N2 caused about 34,000 deaths in the United States. This virus was first detected in Hong Kong in early 1968, and spread to the United States later that year. This pandemic of 1968 and 1969 killed approximately one million people worldwide
. Influenza A (H3N2) viruses still circulate today.

Typhus

Typhus is sometimes called "camp fever" because of its pattern of flaring up in times of strife. (It is also known as "gaol fever" and "ship fever", for its habits of spreading wildly in cramped quarters, such as jails and ships.) Emerging during the Crusades, it had its first impact in Europe in 1489, in Spain. During fighting between the Christian Spaniards and the Muslims in Granada, 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 (1618–1648), about 8 million Germans were killed by bubonic plague and typhus. The disease also played a major role in the destruction of Napoleon's Grande Armée in Russia in 1812. During the retreat from Moscow, more French military personnel died of typhus 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 1500–1914 by typhus than from military action. In early 1813, Napoleon raised a new army of 500,000 to replace his Russian losses. In the campaign of that year, over 219,000 of Napoleon's soldiers died of typhus. Typhus played a major factor in the Irish Potato Famine. During World War I, typhus epidemics killed over 150,000 in Serbia. There were about 25 million infections and 3 million deaths from epidemic typhus in Russia from 1918 to 1922. Typhus also killed numerous prisoners in the Nazi concentration camps and Soviet prisoner of war camps during World War II. More than 3.5 million Soviet POWs died out of the 5.7 million in Nazi custody.

Smallpox

Smallpox 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.

Measles

Historically, measles was prevalent throughout the world, as it is highly contagious. According to the U.S. National Immunization Program, 90% of people were infected with measles by age 15. Before the vaccine was introduced in 1963, there were an estimated 3–4 million cases in the U.S. each year. 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 that 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 killed two-thirds of the natives who had previously survived smallpox. The disease had ravaged Mexico, Central America, and the Inca civilization.

Tuberculosis

One-third of the world's current population has been infected with Mycobacterium tuberculosis, and new infections occur at a rate of one per second. About 5–10% of these latent infections will eventually progress to active disease, which, if left untreated, kills more than half of its victims. Annually, 8 million people become ill with tuberculosis, and 2 million people die from the disease worldwide. 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.

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 leprosaria, or leper hospitals, sprang up in the Middle Ages; Matthew Paris estimated that in the early 13th century, there were 19,000 of them across Europe.

Malaria

Malaria is widespread in tropical and subtropical regions, including parts of the Americas, Asia, and Africa. Each year, there are approximately 350–500 million cases of malaria. Drug resistance 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 disease became known as "Roman fever". Plasmodium falciparum became a real threat to colonists and indigenous 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, there were over 1.2 million cases of malaria among soldiers of both sides. The southern U.S. continued to be afflicted with millions of cases of malaria into the 1930s.

Yellow fever

Yellow fever 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. In colonial times, West Africa became known as "the white man's grave" because of malaria and yellow fever.

Concern about possible future pandemics

Viral hemorrhagic fevers

Viral hemorrhagic fevers such as Ebola virus disease, Lassa fever virus, Rift Valley fever, Marburg virus and Bolivian hemorrhagic fever 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 only has 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 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.

Antibiotic resistance

Antibiotic-resistant microorganisms, sometimes referred to as "superbugs", may contribute to the re-emergence of diseases which 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 (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, Serratia marcescens and Enterococcus, have developed resistance to various antibiotics 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.

SARS

In 2003 the Italian physician Carlo Urbani (1956–2003) was the first to identify severe acute respiratory syndrome (SARS) as a new and dangerously contagious disease, although he became infected and died. It is caused by a corona virus dubbed SARS-CoV. Rapid action by national and international health authorities such as the World Health Organization 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. It 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, 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, 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 Asian Flu virus were accidentally spread around the world from a lab in the US.

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 yet 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 have been very 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 only attach 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 began in 2015 and strongly intensified throughout the start of 2016, with over 1.5 million cases across more than a dozen countries in the Americas. The World Health Organisation warned that Zika had the potential to become an explosive global pandemic if the outbreak was not controlled.

Economic consequences of pandemic events

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 also recommended spending $4.5 billion annually on global prevention and response capabilities to reduce the threat posed by pandemic events.

Biological warfare

In 1346, the bodies of Mongol warriors who had died of plague were thrown over the walls of the besieged Crimean city of Kaffa (now Theodosia). After a protracted siege, during which the Mongol army under Jani Beg was suffering the disease, they catapulted the infected corpses over the city walls to infect the inhabitants. It has been speculated that this operation may have been responsible for the arrival of the Black Death in Europe.

The Native American population was devastated after contact with the Old World by introduction of many fatal diseases. In a well documented case of germ warfare involving British commander Jeffery Amherst and Swiss-British officer Colonel Henry Bouquet, their correspondence included a proposal and agreement to give smallpox-infected blankets to Indians in order to "Extirpate this Execrable Race". During the siege of Fort Pitt late in the French and Indian War, as recorded in his journal by sundries trader and militia Captain, William Trent, on June 24, 1763, dignitaries from the Delaware tribe met with Fort Pitt officials, warned them of "great numbers of Indians" coming to attack the fort, and pleaded with them to leave the fort while there was still time. The commander of the fort refused to abandon the fort. Instead, the British gave as gifts two blankets, one silk handkerchief and one linen from the smallpox hospital to two Delaware Indian dignitaries. A devastating smallpox epidemic plagued Native American tribes in the Ohio Valley and Great Lakes area through 1763 and 1764, but the effectiveness of individual instances of biological warfare remains unknown. After extensive review of surviving documentary evidence, historian Francis Jennings concluded the attempt at biological warfare was "unquestionably effective at Fort Pitt"; Smallpox after Pontiac's Rebellion killed 400,000–500,000 (possibly even up to 1.5 million) Native Americans.

During the Sino-Japanese War (1937–1945), Unit 731 of the Imperial Japanese Army conducted human experimentation on thousands, mostly Chinese. In military campaigns, the Japanese army used biological weapons on Chinese soldiers and civilians. Plague fleas, infected clothing, and infected supplies encased in bombs were dropped on various targets. The resulting cholera, anthrax, and plague were estimated to have killed around 400,000 Chinese civilians.


Spores of weaponized anthrax were accidentally released from a military facility near the Soviet closed city of Sverdlovsk in 1979. The Sverdlovsk anthrax leak is sometimes called "biological Chernobyl". In January 2009, an Al-Qaeda training camp in Algeria was reportedly wiped out by the plague, killing approximately 40 Islamic extremists. Some experts said that the group was developing biological weapons, however, a couple of days later the Algerian Health Ministry flatly denied this rumour stating "No case of plague of any type has been recorded in any region of Algeria since 2003".

In popular culture

Pandemics appear in multiple fiction works. A common use is in disaster films, where the protagonists must avoid the effects of the plague, for example zombies

Literature
Film
Television
  • Helix (2014–2015), a television series that depicts a team of scientists from the Centers for Disease Control and Prevention who are tasked to prevent pandemics from occurring.
  • The Last Man on Earth (2015–), a television series about a group of survivors after a pandemic has wiped out most life (humans and animals) on Earth
  • 12 Monkeys (2015–), a television series that depicts James Cole, a time traveler, who travels from the year 2043 to the present day to stop the release of a deadly virus.
  • Survivors (1975–1977), classic BBC series created by Terry Nation. The series follows a group of people as they come to terms with the aftermath of a world pandemic.
  • Survivors (2008), BBC series, loosely based on the Terry Nation book that came after the series, instead of a retelling of the original TV series.
  • The Last Train 1999 written by Matthew Graham
Games
  • Pandemic (2008), a cooperative board game in which the players have to discover the cures for four diseases that break out at the same time.
  • Plague Inc. (2012), a smartphone game clone from Ndemic Creations, copied from the original Pandemic Web browser Flash game from Dark Realm Studios
  • The Last of Us (2013), a post-apocalyptic survival game on PS3 and PS4 by Naughty Dog.
  • Tom Clancy's The Division (2015) A video game about a bioterrorist attack that has devastated the United States and thrown New York into anarchy.

Globalization and disease

From Wikipedia, the free encyclopedia

Globalization, the flow of information, goods, capital, and people across political and geographic boundaries, allows infectious diseases to rapidly spread around the world, while also allowing the alleviation of factors such as hunger and poverty, which are key determinants of global health. The spread of diseases across wide geographic scales has increased through history. Early diseases that spread from Asia to Europe were bubonic plague, influenza of various types, and similar infectious diseases.

In the current era of globalization, the world is more interdependent than at any other time. Efficient and inexpensive transportation has left few places inaccessible, and increased global trade in agricultural products has brought more and more people into contact with animal diseases that have subsequently jumped species barriers (see zoonosis).

Globalization intensified during the Age of Exploration, but trading routes had long been established between Asia and Europe, along which diseases were also transmitted. An increase in travel has helped spread diseases to natives of lands who had not previously been exposed. When a native population is infected with a new disease, where they have not developed antibodies through generations of previous exposure, the new disease tends to run rampant within the population.

Etiology, the modern branch of science that deals with the causes of infectious disease, recognizes five major modes of disease transmission: airborne, waterborne, blood borne, by direct contact, and through vector (insects or other creatures that carry germs from one species to another). As humans began traveling over seas and across lands which were previously isolated, research suggests that diseases have been spread by all five transmission modes.

Travel patterns and globalization

The Age of Exploration generally refers to the period between the 15th and 17th centuries. During this time, technological advances in shipbuilding and navigation made it easier for nations to explore outside previous boundaries. Globalization has had many benefits, for example, new products to Europeans were discovered, such as tea, silk and sugar when Europeans developed new trade routes around Africa to India and the Spice Islands, Asia, and eventually running to the Americas

In addition to trading in goods, many nations began to trade in slavery. Trading in slaves was another way by which diseases were carried to new locations and peoples, for instance, from sub-Saharan Africa to the Caribbean and the Americas. During this time, different societies began to integrate, increasing the concentration of humans and animals in certain places, which led to the emergence of new diseases as some jumped in mutation from animals to humans. 

During this time sorcerers' and witch doctors' treatment of disease was often focused on magic and religion, and healing the entire body and soul, rather than focusing on a few symptoms like modern medicine. Early medicine often included the use of herbs and meditation. Based on archeological evidence, some prehistoric practitioners in both Europe and South America used trephining, making a hole in the skull to release illness. Severe diseases were often thought of as supernatural or magical. The result of the introduction of Eurasian diseases to the Americas was that many more native peoples were killed by disease and germs than by the colonists' use of guns or other weapons. Scholars estimate that over a period of four centuries, epidemic diseases wiped out as much as 90 percent of the American indigenous populations.

In Europe during the age of exploration, diseases such as smallpox, measles and tuberculosis (TB) had already been introduced centuries before through trade with Asia and Africa. People had developed some antibodies to these and other diseases from the Eurasian continent. When the Europeans traveled to new lands, they carried these diseases with them. (Note: Scholars believe TB was already endemic in the Americas.) When such diseases were introduced for the first time to new populations of humans, the effects on the native populations were widespread and deadly. The Columbian Exchange, referring to Christopher Columbus's first contact with the native peoples of the Caribbean, began the trade of animals, and plants, and unwittingly began an exchange of diseases.

It was not until the 1800s that humans began to recognize the existence and role of germs and microbes in relation to disease. Although many thinkers had ideas about germs, it was not until Louis Pasteur spread his theory about germs, and the need for washing hands and maintaining sanitation (particularly in medical practice), that anyone listened. Many people were quite skeptical, but on May 22, 1881 Pasteur persuasively demonstrated the validity of his germ theory of disease with an early example of vaccination. The anthrax vaccine was administered to 25 sheep while another 25 were used as a control. On May 31, 1881 all of the sheep were exposed to anthrax. While every sheep in the control group died, each of the vaccinated sheep survived. Pasteur’s experiment would become a milestone in disease prevention. His findings, in conjunction with other vaccines that followed, changed the way globalization affected the world.

Effects of globalization on disease in the modern world

Modern modes of transportation allow more people and products to travel around the world at a faster pace; they also open the airways to the transcontinental movement of infectious disease vectors. One example is the West Nile Virus. It is believed that this disease reached the United States via “mosquitoes that crossed the ocean by riding in airplane wheel wells and arrived in New York City in 1999.” With the use of air travel, people are able to go to foreign lands, contract a disease and not have any symptoms of illness until after they get home, and having exposed others to the disease along the way. 

As medicine has progressed, many vaccines and cures have been developed for some of the worst diseases (plague, syphilis, typhus, cholera, malaria) which people suffer. But, because the evolution of disease organisms is very rapid, even with vaccines, there is difficulty providing full immunity to many diseases. Finding vaccines at all for some diseases remains extremely difficult. Without vaccines, the global world remains vulnerable to infectious diseases. 

Evolution of disease presents a major threat in modern times. For example, the current "swine flu" or H1N1 virus is a new strain of an old form of flu, known for centuries as Asian flu based on its origin on that continent. From 1918–1920, a post-World War I global influenza epidemic killed an estimated 50–100 million people, including half a million in the United States alone. H1N1 is a virus that has evolved from and partially combined with portions of avian, swine, and human flu.

Globalization has increased the spread of infectious diseases from South to North, but also the risk of non-communicable diseases by transmission of culture and behavior from North to South. It is important to target and reduce the spread of infectious diseases in developing countries. However, addressing the risk factors of non-comunicable diseases and lifestyle risks in the South that cause disease, such as use or consumption of tobacco, alcohol, and unhealthy foods, is important as well.[9]

Specific diseases

Plague

Bubonic plague is a variant of the deadly flea-borne disease plague, which is caused by the enterobacteria Yersinia pestis, that devastated human populations beginning in the 14th century. Bubonic plague is primarily spread by fleas that lived on the black rat, an animal that originated in south Asia and spread to Europe by the 6th century. It became common to cities and villages, traveling by ship with explorers. A human would become infected after being bitten by an infected flea. The first sign of an infection of bubonic plague is swelling of the lymph nodes, and the formation of buboes. These buboes would first appear in the groin or armpit area, and would often ooze pus or blood. Eventually infected individuals would become covered with dark splotches caused by bleeding under the skin. The symptoms would be accompanied by a high fever, and within four to seven days of infection, more than half the victims would die. During the 14th and 15th century, humans did not know that a bacterium was the cause of plague, and efforts to slow the spread of disease were futile. 

The first recorded outbreak of plague occurred in China in the 1330s, a time when China was engaged in substantial trade with western Asia and Europe. The plague reached Europe in October 1347. It was thought to have been brought into Europe through the port of Messina, Sicily, by a fleet of Genoese trading ships from Kaffa, a seaport on the Crimean peninsula. When the ship left port in Kaffa, many of the inhabitants of the town were dying, and the crew was in a hurry to leave. By the time the fleet reached Messina, all the crew were either dead or dying; the rats that took passage with the ship slipped unnoticed to shore and carried the disease with them and their fleas.

Within Europe, the plague struck port cities first, then followed people along both sea and land trade routes. It raged through Italy into France and the British Isles. It was carried over the Alps into Switzerland, and eastward into Hungary and Russia. For a time during the 14th and 15th centuries, the plague would recede. Every ten to twenty years, it would return. Later epidemics, however, were never as widespread as the earlier outbreaks, when 60% of the population died.

The plague has never died out. From 1896–1918 the plague swept through India, taking the lives of over 12.5 million people. Between 1906 and 1914, the Plague Research Commission was created, and published supplements to the Journal of Hygiene.

Measles

Measles is a highly contagious airborne virus spread by contact with infected oral and nasal fluids. When a person with measles coughs or sneezes, he releases microscopic particles into the air. During the 4- to 12-day incubation period, an infected individual shows no symptoms, but as the disease progresses, the following symptoms appear: runny nose, cough, red eyes, extremely high fever and a rash. 

Measles is an endemic disease, meaning that it has been continually present in a community, and many people developed resistance. In populations that have not been exposed to measles, exposure to the new disease can be devastating. In 1529, a measles outbreak in Cuba killed two-thirds of the natives who had previously survived smallpox. Two years later measles was responsible for the deaths of half the indigenous population of Honduras, and ravaged Mexico, Central America, and the Inca civilization.

Historically, measles was very prevalent throughout the world, as it is highly contagious. According to the National Immunization Program, 90% of people were infected with measles by age 15, acquiring immunity to further outbreaks. Until a vaccine was developed in 1963, measles was considered to be deadlier than smallpox. Vaccination reduced the number of reported occurrences by 98%. Major epidemics have predominantly occurred in unvaccinated populations, particularly among nonwhite Hispanic and African American children under 5 years old. In 2000 a group of experts determined that measles was no longer endemic in the United States. The majority of cases that occur are among immigrants from other countries.

Typhus

Typhus is caused by rickettsia, which is transmitted to humans through lice. The main vector for typhus is the rat flea. Flea bites and infected flea feces in the respiratory tract are the two most common methods of transmission. In areas where rats are not common, typhus may also be transmitted through cat and opossum fleas. The incubation period of typhus is 7–14 days. The symptoms start with a fever, then headache, rash, and eventually stupor. Spontaneous recovery occurs in 80–90% of victims. 

The first outbreak of typhus was recorded in 1489. Historians believe that troops from the Balkans, hired by the Spanish army, brought it to Spain with them. By 1490 typhus traveled from the eastern Mediterranean into Spain and Italy, and by 1494, it had swept across Europe. From 1500–1914, more soldiers were killed by typhus than from all the combined military actions during that time. It was a disease associated with the crowded conditions of urban poverty and refugees as well. Finally, during World War I, governments instituted preventative delousing measures among the armed forces and other groups, and the disease began to decline. The creation of antibiotics has allowed disease to be controlled within two days of taking a 200 mg dose of tetracycline.

Syphilis

Syphilis is a sexually transmitted disease that causes open sores, delirium and rotting skin, and is characterized by genital ulcers. Syphilis can also do damage to the nervous system, brain and heart. The disease can be transmitted from mother to child.

The origins of syphilis are unknown, and some historians argue that it descended from a twenty-thousand-year-old African zoonosis. Other historians place its emergence in the New World, arguing that the crews of Columbus’s ships first brought the disease to Europe. The first recorded case of syphilis occurred in Naples in 1495, after King Charles VIII of France besieged the city of Naples, Italy. The soldiers, and the prostitutes who followed their camps, came from all corners of Europe. When they went home, they took the disease with them and spread it across the continent.

Smallpox

Smallpox is a highly contagious disease caused by the Variola virus. There are four variations of smallpox; variola major, variola minor, hemorrhagic, and malignant, with the most common being variola major and variola minor. Symptoms of the disease including hemorrhaging, blindness, back ache, vomiting, which generally occur shortly after the 12- to 17-day incubation period. The virus begins to attack skin cells, and eventually leads to an eruption of pimples that cover the whole body. As the disease progresses, the pimples fill up with pus or merge. This merging results in a sheet that can detach the bottom layer from the top layer of skin. The disease is easily transmitted through airborne pathways (coughing, sneezing, and breathing), as well as through contaminated bedding, clothing or other fabrics.

It is believed that smallpox first emerged over 3000 years ago, probably in India or Egypt. There have been numerous recorded devastating epidemics throughout the world, with high losses of life. 

Smallpox was a common disease in Eurasia in the 15th century, and was spread by explorers and invaders. After Columbus landed on the island of Hispaniola during his second voyage in 1493, local people started to die of a virulent infection. Before the smallpox epidemic started, more than one million indigenous people had lived on the island; afterward, only ten thousand had survived.

During the 16th century, Spanish soldiers introduced smallpox by contact with natives of the Aztec capital Tenochtitlan. A devastating epidemic broke out among the indigenous people, killing thousands.

In 1617, smallpox reached Massachusetts, probably brought by earlier explorers to Nova Scotia, Canada.” By 1638 the disease had broken out among people in Boston, Massachusetts. In 1721 people fled the city after an outbreak, but the residents spread the disease to others throughout the thirteen colonies. Smallpox broke out in six separate epidemics in the United States through 1968.

The smallpox vaccine was developed in 1798 by Edward Jenner. By 1979 the disease had been completely eradicated, with no new outbreaks. The WHO stopped providing vaccinations and by 1986, vaccination was no longer necessary to anyone in the world except in the event of future outbreak.

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. Symptoms often include irritation or erosion of the skin, and effects on the peripheral nerves, mucosa of the upper respiratory tract and eyes. The most common sign of leprosy are pale reddish spots on the skin that lack sensation.

Leprosy probably originated in India, more than four thousand years ago. It was prevalent in ancient societies in China, Egypt and India, and was transmitted throughout the world by various traveling groups, including Roman Legionnaires, Crusaders, Spanish conquistadors, Asian seafarers, European colonists, and Arab, African, and American slave traders. Some historians believe that Alexander the Great's troops brought leprosy from India to Europe during the 3rd century BC. With the help of the crusaders and other travelers, leprosy reached epidemic proportions by the 13th century. 

Once detected, leprosy can be cured using multi-drug therapy, composed of two or three antibiotics, depending on the type of leprosy. In 1991 the World Health Assembly began an attempt to eliminate leprosy. By 2005 116 of 122 countries were reported to be free of leprosy.

Malaria

On Nov. 6, 1880 Alphonse Laveran discovered that malaria (then called "Marsh Fever") was a protozoan parasite, and that mosquitoes carry and transmit malaria. Malaria is a protozoan infectious disease that is generally transmitted to humans by mosquitoes between dusk and dawn. The European variety, known as "vivax" after the Plasmodium vivax parasite, causes a relatively mild, yet chronically aggravating disease. The west African variety is caused by the sporozoan parasite, Plasmodium falciparum, and results in a severely debilitating and deadly disease.

Malaria was common in parts of the world where it has now disappeared, as the vast majority of Europe (disease of African descent are particularly diffused in the Empire romain) and North America . In some parts of England, mortality due to malaria was comparable to that of sub-Saharan Africa today. Although William Shakespeare was born at the beginning of a colder period called the "Little Ice Age", he knew enough ravages of this disease to include in eight parts. Plasmodium vivax lasted until 1958 in the polders of Belgium and the Netherlands. In the 1500s, it was the European settlers and their slaves who probably brought malaria on the American continent (we know that Columbus was suffering from this disease before his arrival in the new land). The Spanish Jesuit missionaries saw the Indians bordering on Lake Loxa Peru used the Cinchona bark powder to treat fevers. However, there is no reference to malaria in the medical literature of the Maya or Aztecs. The use of the bark of the "fever tree" was introduced into European medicine by Jesuit missionaries whose Barbabe Cobo who experimented in 1632 and also exports, so that the precious powder s' also called "Jesuit powder" . A study in 2012 of thousands of genetic markers for Plasmodium falciparum samples confirmed the African origin of the parasite in South America (Europeans themselves have been affected by this disease through Africa): it borrowed from the mid-sixteenth century and the mid-nineteenth the two main roads of the slave trade, the first leading to the north of South America (Colombia) by the Spanish, the second most leading south (Brazil) by Portugueses. 

Parts of the Third World are more affected by malaria than the rest of the world. For instance, many inhabitants of sub-Saharan Africa are affected by recurring attacks of malaria throughout their lives. In many areas of Africa, there is limited running water. The residents' use of wells and cisterns provides many sites for the breeding of mosquitoes and spread of the disease. Mosquitoes use areas of standing water like marshes, wetlands, and water drums to breed.

Tuberculosis

The bacterium that causes tuberculosis, Mycobacterium tuberculosis, is generally spread when an infected person coughs and another person inhales the bacteria. Once inhaled TB frequently grows in the lungs, but can spread to any part of the body. Although TB is highly contagious, in most cases the human body is able to fend off the bacteria. But, TB can remain dormant in the body for years, and become active unexpectedly. If and when the disease does become active in the body, it can multiply rapidly, causing the person to develop many symptoms including cough (sometimes with blood), night sweats, fever, chest pains, loss of appetite and loss of weight. This disease can occur in both adults and children and is especially common among those with weak or undeveloped immune systems.

Tuberculosis (TB) has been one of history’s greatest killers, taking the lives of over 3 million people annually. It has been called the "white plague". According to the WHO, approximately fifty percent of people infected with TB today live in Asia. It is the most prevalent, life-threatening infection among AIDS patients. It has increased in areas where HIV seroprevalence is high.

Air travel and the other methods of travel which have made global interaction easier, have increased the spread of TB across different societies. Luckily, the BCG vaccine was developed, which prevents TB meningitis and miliary TB in childhood. But, the vaccine does not provide substantial protection against the more virulent forms of TB found among adults. Most forms of TB can be treated with antibiotics to kill the bacteria. The two antibiotics most commonly used are rifampicin and isoniazid. There are dangers, however, of a rise of antibiotic-resistant TB. The TB treatment regimen is lengthy, and difficult for poor and disorganized people to complete, increasing resistance of bacteria. Antibiotic-resistant TB is also known as "multidrug-resistant tuberculosis." "Multidrug-resistant tuberculosis" is a pandemic that is on the rise. Patients with MDR-TB are mostly young adults who are not infected with HIV or have other existing illness. Due to the lack of health care infrastructure in underdeveloped countries, there is a debate as to whether treating MDR-TB will be cost effective or not. The reason is the high cost of "second-line" antituberculosis medications. It has been argued that the reason the cost of treating patients with MDR-TB is high is because there has been a shift in focus in the medical field, in particular the rise of AIDS, which is now the world's leading infectious cause of death. Nonetheless, it is still important to put in the effort to help and treat patients with "multidrug-resistant tuberculosis" in poor countries.

HIV/AIDS

HIV and AIDS are among the newest and deadliest diseases. According to the World Health Organization, it is unknown where the HIV virus originated, but it appeared to move from animals to humans. It may have been isolated within many groups throughout the world. It is believed that HIV arose from another, less harmful virus, that mutated and became more virulent. The first two AIDS/HIV cases were detected in 1981. As of 2013, an estimated 1.3 million persons in the United States were living with HIV or AIDS, almost 110,000 in the UK  and an estimated 35 million people worldwide are living with HIV”.

Despite efforts in numerous countries, awareness and prevention programs have not been effective enough to reduce the numbers of new HIV cases in many parts of the world, where it is associated with high mobility of men, poverty and sexual mores among certain populations. Uganda has had an effective program, however. Even in countries where the epidemic has a very high impact, such as Swaziland and South Africa, a large proportion of the population do not believe they are at risk of becoming infected. Even in countries such as the UK, there is no significant decline in certain at-risk communities. 2014 saw the greatest number of new diagnoses in gay men, the equivalent of nine being diagnosed a day.

Initially, HIV prevention methods focused primarily on preventing the sexual transmission of HIV through behavior change. The ABC Approach - "Abstinence, Be faithful, Use a Condom". However, by the mid-2000s, it became evident that effective HIV prevention requires more than that and that interventions need to take into account underlying socio-cultural, economic, political, legal and other contextual factors.

Ebola

The Ebola outbreak, which was the 26th outbreak since 1976, started in Guinea in March 2014. The WHO warned that the number of Ebola patients could rise to 20,000, and said that it used $489m (£294m) to contain Ebola within six to nine months. The outbreak was accelerating. Medecins sans Frontieres has just opened a new Ebola hospital in Monrovia, and after one week it is already a capacity of 120 patients. It said that the number of patients seeking treatment at its new Monrovia center was increasing faster than they could handle both in terms of the number of beds and the capacity of the staff, adding that it was struggling to cope with the caseload in the Liberian capital. Lindis Hurum, MSF's emergency coordinator in Monrovia, said that it was humanitarian emergency and they needed a full-scale humanitarian response. Brice de la Vinge, MSF director of operations, said that it was not until five months after the declaration of the Ebola outbreak that serious discussions started about international leadership and coordination, and said that it was not acceptable.

Leptospirosis

Leptospirosis, also known as field fever is an infection caused by Leptospira. Symptoms can range from none to mild such as headaches, muscle pains, and fevers; to severe with bleeding from the lungs or meningitis. Leptospira is transmitted by both wild and domestic animals, most commonly by rodents. It is often transmitted by animal urine or by water or soil containing animal urine coming into contact with breaks in the skin, eyes, mouth, or nose. The countries with the highest reported incidence are located in the Asia-Pacific region (Seychelles, India, Sri Lanka and Thailand) with incidence rates over 10 per 1000,000 people s well as in Latin America and the Caribbean (Trinidad and Tobago, Barbados, Jamaica, El Salvador, Uruguay, Cuba, Nicaragua and Costa Rica). However, the rise in global travel and eco-tourism  has led to dramatic changes in the epidemiology of leptospirosis, and travelers from around the world have become exposed to the threat of leptospirosis. Despite decreasing prevalence of leptospirosis in endemic regions, previously non-endemic countries are now reporting increasing numbers of cases due to recreational exposure  International travelers engaged in adventure sports are directly exposed to numerous infectious agents in the environment and now comprise a growing proportion of cases worldwide.

Non-communicable disease

Globalization can benefit people with non-communicable diseases such as heart problems or mental health problems. Global trade and rules set forth by the World Trade Organization can actually benefit the health of people by making their incomes higher, allowing them to afford better health care. While it has to be admitted making many non-communicable diseases more likely as well. Also the national income of a country, mostly obtained by trading on the global market, is important because it dictates how much a government spends on health care for its citizens. It also has to be acknowledged that an expansion in the definition of disease often accompanies development, so the net effect is not clearly beneficial due to this and other effects of increased affluence. Metabolic syndrome is one obvious example. Although poorer countries have not yet experienced this and are still suffering from diseases listed above.

Child abandonment

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Child_abandonment ...