Las grandes epidemias y pandemias - Historia y resumen en mapas

Summary

This script chronicles the evolution of human settlement and agriculture, leading to the emergence of infectious diseases. It details significant historical pandemics, such as the Plague of Athens, the Antonine Plague, the Justinian Plague, the Black Death, and the Spanish flu, highlighting their impact on civilizations. It also discusses the spread of diseases like leprosy, syphilis, and cholera, and the medical advancements that arose in response, including the development of vaccines. The script concludes with the emergence of modern pandemics like HIV/AIDS and COVID-19, emphasizing the ongoing struggle against infectious diseases, particularly affecting impoverished populations.

Takeaways

• 🏡 Around 9000 BCE, humans transitioned from a nomadic hunter-gatherer lifestyle to a settled agricultural one, primarily in Mesopotamia, leading to the development of animal husbandry and increased disease transmission.
• 🌱 The close proximity between humans and animals facilitated the spread of diseases, which, along with increased food production, led to the growth of communities, cities, and the emergence of trade routes and wars, further spreading contagious diseases.
• 📚 The first epidemics are likely undocumented, but early records such as religious texts and Egyptian papyri mention them, with the first pandemic possibly occurring around 430 BCE, known as the Plague of Athens.
• 🤒 The Plague of Athens, still unidentified, is said to have originated in Ethiopia and spread to Egypt, Libya, and the Mediterranean basin, affecting Athens during wartime and contributing to a significant population loss.
• 😷 The Antonine Plague around 165 CE, likely a smallpox pandemic, emerged in Mesopotamia and spread with military movements, killing millions and impacting the Roman Empire significantly.
• 🦇 The first recorded bubonic plague pandemic, the Plague of Justinian, began in 541 CE, spreading from Central Asia to the Byzantine Empire and affecting trade and military expansion, with long-term effects on the empires involved.
• 🏥 Leprosy, a bacterial disease, is mentioned in ancient texts and likely originated in East Africa, spreading through trade routes and affecting densely populated areas of Europe.
• 💀 The Black Death, the second bubonic plague pandemic, originated in Central Asia and spread across Europe, with the Genoese traders contributing to its dissemination, causing massive mortality rates.
• 🛶 The Columbian Exchange following the voyages of Columbus and da Gama led to the introduction of Old World diseases to the New World, with smallpox being particularly devastating to indigenous populations.
• 🧬 The evolution of medicine saw advancements like the smallpox vaccine, developed after observing that cowpox carriers were immune to smallpox, leading to the eradication of the disease over two centuries.
• 🌐 Globalization has facilitated the rapid spread of diseases like COVID-19, which was declared a pandemic by the WHO in March 2020, highlighting the ongoing challenges of containing infectious diseases in an interconnected world.

Q & A

What significant shift in human lifestyle occurred around 9000 BCE?

Around 9000 BCE, humans gradually transitioned from a hunter-gatherer lifestyle to a settled one, with the development of agriculture and animal husbandry, primarily in Mesopotamia.

How did the close proximity of animals to humans during this period affect disease transmission?

The close proximity between animals and humans facilitated the transmission of diseases, leading to the emergence of new infectious diseases.

What event is considered the first pandemic according to a Greek historian's account?

The first pandemic, known as the Plague of Athens, occurred around 430 BCE. It is still unidentified but is believed to have originated in Ethiopia and spread to the Mediterranean basin.

How did the Plague of Athens impact the ongoing war between Athens and Sparta?

The Plague of Athens killed 25 to 30% of Athens' population, which contributed to the victory of Sparta in the ongoing war.

What is the Antonine Plague, and what were its effects on the Roman Empire?

The Antonine Plague, likely a smallpox pandemic, appeared around 165 CE in Mesopotamia and spread quickly to the west. It resulted in the deaths of 5 million people and significantly affected the Roman Empire.

How did the Justinian Plague affect the Byzantine Empire and its military expansion?

The Justinian Plague, starting in 541 CE, affected the Byzantine Empire's capital, Constantinople, and its military troops, interrupting the empire's expansion and contributing to its eventual decline.

What is the Black Death, and how did it spread across Europe?

The Black Death, the second bubonic plague pandemic, originated in Central Asia and spread across Europe, particularly affecting densely populated areas and poor populations. It was spread by rats and fleas and later by infected individuals.

What role did the Catholic Church play in the treatment of leprosy during the Middle Ages?

The Catholic Church considered lepers as already dead and isolated them in leprosariums, ranging from simple huts to more established facilities in cities, where they were completely cut off from the outside world.

How did the discovery of the Americas and the subsequent increase in global trade affect the spread of diseases?

The discovery of the Americas and increased global trade led to the exchange of diseases between the Old and New Worlds. The Old World introduced diseases like smallpox to the New World, which had devastating effects on the indigenous populations.

What was the significance of the smallpox vaccine developed in the late 18th century?

The smallpox vaccine, developed after observing that individuals with cowpox were protected from smallpox, was the first vaccine and marked a significant advancement in medicine, eventually leading to the eradication of smallpox in two centuries.

How did the Spanish flu pandemic of 1918 impact the world during World War I?

The Spanish flu pandemic, which began during World War I, infected a third of the world's population and resulted in approximately 50 million deaths, spreading globally due to the movement of soldiers and civilians.

What is the current status of HIV/AIDS as a pandemic, and how has it affected the global population?

HIV/AIDS, which was identified in 1983, is considered a pandemic since 2005. It has claimed the lives of around 30 million people in the past 30 years, and currently, nearly 40 million people live with HIV.

How did the COVID-19 pandemic start, and what was the World Health Organization's response?

The COVID-19 pandemic likely started in November 2019 with the transmission of the SARS-CoV-2 virus from animals to humans in Wuhan, China. The World Health Organization declared it a pandemic on March 11, 2020, due to its rapid global spread.

Outlines

00:00

🏺 Early Agricultural Transition and the Dawn of Epidemics

This paragraph discusses the transition of humans from a hunter-gatherer lifestyle to a settled agricultural one around 9000 BCE, primarily in Mesopotamia. The development of agriculture and animal husbandry led to increased proximity between humans and animals, facilitating the spread of diseases. The growth in food production led to the rise of communities, towns, and cities, along with the emergence of trade routes and warfare, which in turn facilitated the spread of contagious diseases. Although historical records are scarce, the first epidemics and possibly pandemics are believed to have occurred during this time, with the first pandemic documented by a Greek historian around 430 BCE, known as the Plague of Athens. This disease, unidentified to this day, originated in Ethiopia and spread across the Mediterranean, severely affecting Athens during a time of war and siege, contributing to a significant portion of the population's death and aiding Sparta's victory. The paragraph also mentions the Antonine Plague around 165 CE, likely a smallpox pandemic, and the first recorded bubonic plague pandemic, the Plague of Justinian, in 541 CE, both of which had profound impacts on the Roman Empire and the Byzantine Empire, respectively.

05:04

😷 The Black Death and the Spread of Leprosy

The Black Death, the second bubonic plague pandemic, is the focus of this paragraph. Originating in Central Asia, it spread across the continent, notably affecting Europe. The disease was particularly devastating to densely populated areas, killing an estimated 200 million people worldwide, which included nearly half of Europe's population. The continent took two centuries to recover demographically. The paragraph also discusses the leprosy, a bacterial disease mentioned in ancient texts, which likely originated in East Africa and spread through trade routes. Poor hygiene and living conditions in Europe facilitated the spread of leprosy, which was particularly impactful on the poor. Measures of exclusion were taken against those affected, with the Catholic Church viewing lepers as already dead, leading to their isolation in leper colonies.

10:04

🌐 Global Exploration and the Exchange of Diseases

This paragraph details the impact of global exploration on the spread of diseases. With the arrival of Christopher Columbus in the Americas and Vasco da Gama's maritime route to the Indies, commercial exchanges intensified between populations with different immunities. The Old World introduced a dozen unknown diseases to the New World, with smallpox being particularly devastating to the indigenous populations. Conversely, a particularly virulent form of syphilis was imported from America to Europe. Additionally, tropical diseases like yellow fever and malaria spread globally through trade routes. The paragraph also highlights the evolution of medicine in response to these diseases, with the development of the first vaccine for smallpox by Edward Jenner in 1796, which eventually led to the eradication of the disease in two centuries.

🌍 The Cholera Pandemics and the Spanish Influenza

The paragraph discusses the cholera pandemics, which began in 1817 near Bengal and spread across Asia, Africa, and Europe, with five subsequent pandemics affecting the world. It also covers the third and final bubonic plague pandemic, which started in 1855 in China and spread globally via ships. The discovery of the bacteria responsible for the plague and the role of rat fleas in its transmission led to the creation of a serum and measures to limit infections. The paragraph then shifts to the topic of influenza, with the first major pandemic, the Russian flu of 1889-1890, and the devastating Spanish flu of 1918, which infected a third of the world's population and resulted in approximately 50 million deaths. Subsequent pandemics, such as the Asian flu in 1957 and the Hong Kong flu in 1968, are also mentioned.

🦠 The Emergence of HIV/AIDS and the COVID-19 Pandemic

This final paragraph addresses the emergence of HIV/AIDS, which originated from chimpanzees to humans through hunting and slowly spread to become a pandemic by 2005. The identification of the HIV virus by the Pasteur Institute in 1983 and the subsequent development of prevention methods and treatments have helped to curb the disease, which has claimed approximately 30 million lives in the past 30 years. The paragraph concludes with the probable transmission of the SARS-CoV-2 virus from animals to humans in Wuhan, China, in late 2019, leading to the COVID-19 pandemic declared by the World Health Organization in March 2020. The paragraph also notes the ongoing impact of other diseases such as endemic plague, cholera, leprosy, seasonal flu, and malaria, which continue to claim many lives, particularly affecting poor and remote populations.

Keywords

💡Cultivation

Cultivation refers to the practice of growing plants and raising animals for food, which marks a significant shift from a nomadic hunter-gatherer lifestyle to a settled agricultural one. In the video, the development of agriculture and animal husbandry, particularly in Mesopotamia, is highlighted as a pivotal moment in human history that led to increased food production and the rise of communities and cities.

💡Zoonosis

Zoonosis is the transmission of diseases from animals to humans. The video script mentions how the close proximity between animals and humans due to cultivation and animal husbandry facilitated the transmission of zoonotic diseases, which became a significant factor in the emergence of new infectious diseases.

💡Epidemic

An epidemic is a widespread occurrence of an infectious disease in a community at a particular time. The video discusses the likely emergence of the first epidemics around 9000 BCE, possibly leading to pandemics, which are widespread epidemics across multiple regions. The script uses the term to illustrate how human settlements and trade routes facilitated the spread of diseases.

💡Pandemic

A pandemic is an epidemic that has spread over several countries or continents, affecting a large number of people. The video provides examples of pandemics such as the Plague of Athens in 430 BCE and the Antonine Plague around 165 CE, showing how these events had profound impacts on ancient societies and their development.

💡Bubonic Plague

Bubonic Plague is a severe bacterial infection caused by the bacterium Yersinia pestis, which is transmitted through the bite of infected fleas that live on small mammals, particularly rats. The video describes the Justinian Plague, the first known pandemic of bubonic plague, which began in Asia Central and spread through trade routes, causing massive death tolls and impacting the Byzantine Empire.

💡Leprosy

Leprosy, also known as Hansen's disease, is a chronic infectious disease caused by the bacteria Mycobacterium leprae. The video mentions leprosy as an ancient bacterial disease that likely originated in East Africa and spread through trade routes. It discusses how leprosy was a significant health issue in densely populated areas of Europe, affecting the poor and leading to social isolation and stigmatization.

💡Black Death

The Black Death, also known as the bubonic plague, was one of the most devastating pandemics in human history. The video describes it as the second pandemic of bubonic plague, which originated in Central Asia and spread across Europe, causing an estimated 200 million deaths and significantly altering the demographic and social landscape of the continent.

💡Quarantine

Quarantine refers to the practice of isolating people or animals that have been exposed to a contagious disease to prevent its spread. The video mentions the establishment of quarantine measures in Venice, where ships had to wait for 40 days before entering the port, marking the invention of quarantine as a public health strategy to control the spread of diseases like the plague.

💡Smallpox

Smallpox is a contagious and often deadly infectious disease caused by the variola virus. The video discusses how smallpox was introduced to the New World by Europeans, causing devastating effects on indigenous populations who had no immunity to the disease. It also highlights the development of the first vaccine for smallpox, which eventually led to its eradication.

💡Cholera

Cholera is an acute intestinal infection caused by the bacterium Vibrio cholerae, which is transmitted through contaminated water or food. The video describes cholera as a bacterial infection that has caused multiple pandemics, with the first pandemic starting in 1817 near Bengal and spreading globally. Cholera outbreaks are often associated with poor sanitation and lack of access to clean water.

💡HIV/AIDS

HIV (Human Immunodeficiency Virus) is the virus that causes AIDS (Acquired Immunodeficiency Syndrome), a condition in which the immune system is severely damaged, making the body more susceptible to infections and diseases. The video explains the origins of HIV, its transmission from chimpanzees to humans, and the subsequent global spread of AIDS. It also discusses the impact of HIV/AIDS on global health and the efforts to prevent and treat the disease.

💡COVID-19

COVID-19 is the disease caused by the SARS-CoV-2 virus, which emerged in late 2019 and led to a global pandemic. The video mentions the rapid spread of COVID-19 due to globalization and international travel, resulting in the World Health Organization declaring it a pandemic in March 2020. The term is used to illustrate the ongoing challenges of infectious disease outbreaks in the modern world.

Highlights

Around 9000 BCE, humans transitioned from a hunter-gatherer lifestyle to a settled agricultural one, primarily in Mesopotamia, leading to the development of animal husbandry and facilitating the spread of diseases.

Increased food production led to the growth of communities, towns, and cities, and the emergence of trade routes and early wars, which in turn facilitated the spread of contagious diseases.

The first epidemics are likely to have occurred around this time, possibly including the first pandemics, which are widespread disease outbreaks across large geographical areas affecting different populations.

The first recorded epidemics are mentioned in religious texts and some Egyptian papyri, with the development of writing allowing for historical accounts, such as the Greek historian's account of the first pandemic around 430 BCE.

The Plague of Athens, unidentified to this day, is considered the first pandemic, originating in Ethiopia and spreading to Egypt, Libya, and the Mediterranean basin, significantly impacting Athens during wartime and contributing to a Spartan victory.

The Antonine Plague around 165 CE, likely a smallpox pandemic, emerged in Mesopotamia and spread rapidly westward following military movements, killing 5 million people and affecting the Roman Empire significantly.

The Justinian Plague in 541 CE marked the first known bubonic plague pandemic, starting in Central Asia and spreading through trade routes to the Byzantine Empire, severely affecting Constantinople and halting the empire's expansion.

The Black Death, the second bubonic plague pandemic, originated from Central Asian steppes and spread across the continent, with the Genoese traders in Caffa contributing to its spread to European port cities.

Leprosy, a bacterial disease mentioned since antiquity, likely originated in East Africa and spread through trade routes to Asia and Europe, with poor populations being the most affected.

The Black Death led to the death of 200 million people worldwide in four years, significantly impacting the population and taking two centuries for Europe to recover demographically.

The introduction of quarantine measures, such as the 40-day waiting period for ships in Venice, was a preventive action against the spread of diseases like the Black Death.

The arrival of European explorers in the Americas brought a dozen unknown diseases to the New World, with smallpox being particularly devastating to the indigenous populations.

The development of the smallpox vaccine by Edward Jenner marked a significant advancement in medicine, with the vaccine eventually leading to the eradication of smallpox within two centuries.

Cholera, a bacterial infection affecting humans through contaminated food or water, caused severe diarrhea and dehydration, leading to high mortality rates in densely populated and unsanitary conditions.

The Spanish flu, the most devastating pandemic of the 20th century, infected a third of the world's population and resulted in approximately 50 million deaths, highlighting the rapid global spread of diseases during wartime.

The HIV/AIDS pandemic, which became recognized as a global health crisis in 2005, has claimed the lives of around 30 million people in the past 30 years, with nearly 40 million people currently living with HIV.

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, exemplifies the rapid spread of diseases facilitated by globalization, being declared a pandemic by the World Health Organization on March 11, 2020.

Despite medical advancements, diseases like plague, cholera, leprosy, seasonal flu, and malaria continue to claim many lives, with poor and remote populations remaining the most affected by these epidemics and pandemics.

Transcripts

Alrededor de 9000 antes de Cristo, los humanos pasan gradualmente

de un estilo de vida de caza-recolección a un estilo de vida sedentario.

Se desarrolla la agricultura y la ganadería, principalmente en Mesopotamia al principio.

La nueva proximidad entre animales y humanos facilita la transmisión de enfermedades.

La producción alimentaria aumenta, las comunidades, los pueblos y luego las ciudades se desarrollan,

rutas comerciales emergen y las primeras guerras aparecen.

Todo esto facilita la propagación de nuevas enfermedades contagiosas.

Aunque no hay suficientes huellas históricas o documentación,

las primeras epidemias probablemente tienen lugar en este momento y tal vez incluso las primeras pandemias,

es decir, la extensión de una epidemia a diferentes pueblos en grandes áreas geográficas.

Las primeras epidemias están relatadas en libros religiosos y en ciertos papiros egipcios.

Gracias al desarrollo de la escritura, el relato de un historiador griego

permite situar una primera pandemia alrededor del año 430 ante Cristo.

Llamada la peste de Atenas, la enfermedad aún no está identificada.

Según el relato y, por lo tanto, el punto de vista griego, la enfermedad aparece en Etiopía,

se extiende a Egipto y Libia y luego a la cuenca del Mediterráneo.

Atenas y Esparta y sus aliados están en guerra.

Atenas, que recibe muchos refugiados, está sitiada.

Demasiado densamente poblada y en condiciones deficientes de higiene,

la peste de Atenas se desarrolla en la ciudad y mata del 25 al 30% de la población,

lo que facilita la victoria espartana.

Alrededor del año 165, cuando la cuenca del Mediterráneo está dominada por el Imperio Romano,

aparece la peste antonina, que es probablemente una pandemia de viruela.

Aparece en Mesopotamia y se extiende rápidamente hacia el oeste tras los movimientos militares.

La enfermedad mata a 5 millones de personas de una población mundial de 200 a 250 millones.

El Imperio Romano está muy afectado.

En los siglos siguientes, otras epidemias lo debilitan aún más,

lo que probablemente tiene un impacto en la caída del Imperio romano de Occidente.

En el año 541, comienza la primera pandemia conocida de peste bubónica.

Es una bacteria que infecta a pequeños mamíferos, principalmente ratas, y sus pulgas.

Las pulgas pueden en algunos casos morder a los humanos y transmitirles la bacteria.

Si la infección llega a los pulmones, se vuelve muy contagiosa entre los humanos.

Según estudios recientes, la peste de Justiniano comienza en Asia Central

y luego se propaga por las rutas comerciales terrestres y marítimas hacia el Imperio Bizantino.

Su capital, Constantinopla, está muy afectada.

Ya que la ciudad es una encrucijada comercial, la enfermedad se propaga por toda la cuenca del Mediterráneo.

Las tropas militares bizantinas desplegadas en el oeste están contaminadas,

interrumpiendo la expansión del imperio.

En Roma, mata al Papa Pelagio II.

Ya sometidos a duras pruebas por la pandemia,

los imperios bizantino y sasánida en Mesopotamia se agotan en una guerra.

Más al sur, esto beneficia a los árabes que entablan conquistas para difundir el Islam.

El Imperio Sasánida se derrumba mientras que el Imperio Bizantino es considerablemente reducido.

La peste de Justiniano se cobra entre 30 y 100 millones de víctimas en dos siglos.

La lepra es una enfermedad bacteriana mencionada en los textos desde la antigüedad.

Según estudios recientes, se originó probablemente en el África oriental

y se propagó a través de Egipto a Asia y Europa a lo largo de las rutas comerciales.

A medida que Europa se puebla densamente, es muy probable que las cruzadas a Jerusalén

acelerarán la propagación de la lepra en el continente.

La mala higiene, la falta de alcantarillado y las viviendas mal ventiladas favorecen la

transmisión de la enfermedad, que sin embargo no es muy contagiosa.

Las poblaciones pobres son las más afectadas.

Se toman medidas de exclusión contra los enfermos.

La religión católica considera que los leprosos ya están muertos.

Están aislados en leproserías, que pueden ser una simple cabaña a la salida de un pueblo

o un establecimiento en las ciudades.

Los enfermos deben terminar sus vidas allí, completamente aislados del mundo exterior.

La Peste Negra es la segunda pandemia de peste bubónica.

Originaria de las estepas de Asia Central, se propaga en todo el continente.

A orillas del Mar Negro, los guerreros de la Horda de Oro asedian el puesto comercial

genovés de Caffa.

Debilitados por la peste, catapultan sus muertos a la ciudad para propagar la enfermedad.

Las ratas probablemente también contaminan la ciudad.

Después del fracaso del asedio, los marineros genoveses reanuden el comercio en toda Europa,

extendiendo la peste a las ciudades portuarias.

La enfermedad se propaga entonces tierra adentro.

Sólo una gran parte de Polonia, Bohemia y Hungría se salva.

La peste se desarrolla particularmente en zonas densamente pobladas y golpea con mayor

fuerza a las poblaciones pobres, desnutridas e insalubres.

Los médicos están abrumados.

En cuatro años, la enfermedad causa 200 millones de muertes en el mundo, incluyendo poco menos

de la mitad de la población europea.

El continente necesitará dos siglos para volver a la demografía que existía antes

de la enfermedad.

La peste negra es endémica, lo que significa que hace varias reapariciones locales en los siglos siguientes.

Aparecen medidas preventivas, en particular en Venecia, donde los barcos deben esperar

40 días antes de entrar en el puerto para asegurarse de que no hay enfermos.

Es la invención de las cuarentenas.

En Europa, la construcción de nuevos barcos más eficientes permite primero a los españoles

y portugueses ampliar sus exploraciones.

Con Cristóbal Colón llegando a América y Vasco da Gama abriendo una ruta marítima

hacia las Indias a lo largo de las costas africanas, los intercambios comerciales se

intensifican rápidamente entre pueblos aislados entre sí y con diferentes inmunidades.

El Viejo Mundo importa una docena de enfermedades aún desconocidas en el Nuevo Mundo.

La viruela es particularmente devastadora entre los amerindios.

Las epidemias diezman pueblos enteros incluso antes de la llegada de los colonos europeos.

A la inversa, una forma particularmente virulenta de sífilis, una infección de transmisión

sexual, se importa de América a Europa.

Además, las rutas comerciales propagan enfermedades tropicales por el mundo como la fiebre amarilla

y el paludismo, también llamado malaria, a través de los mosquitos que acompañan

a los barcos.

Frente a los estragos de las muchas enfermedades, la medicina evoluciona.

En 1768, John Fewster, un boticario inglés, nota que los hombres portadores del virus

de la vacuna, una enfermedad peligrosa para el ganado pero no para los humanos, están

protegidos del virus de la viruela.

Unos años más tarde, el virus de la vacuna se inyecta en la población para contrarrestar

la viruela, es la primera vacuna.

Esta vacuna evoluciona y la enfermedad es erradicada en dos siglos.

El cólera es una infección bacteriana que sólo afecta a los humanos por la ingestión

de alimentos o agua contaminados.

La enfermedad causa una diarrea grave que lleva a una deshidratación severa.

Sin tratamiento, la mitad de los casos muere después de unas horas o unos días.

La enfermedad se propaga con mayor facilidad en las zonas densamente pobladas y en condiciones

de higiene deficientes.

La primera pandemia comienza en 1817 en las cercanías de Bengala y se extiende a Asia,

África y hasta las puertas de Europa.

Cinco pandemias de cólera siguen golpeando al mundo entero.

En 1855, al oeste de Yunnan en China, comienza la tercera y última pandemia de peste bubónica.

Se extiende lentamente a la ciudad portuaria de Hong Kong, desde donde se propaga por los

barcos a los puertos del mundo en pocos años.

Pero esta vez, biólogos y médicos franceses descubren la bacteria responsable de la enfermedad

y el papel de la pulga de la rata en su propagación.

Se crea un suero y se toman medidas para desguazar los barcos, lo que limita el número de infecciones,

principalmente en los países desarrollados.

Las Indias Británicas sin embargo están muy afectadas, con unos 10 millones de muertos,

mientras que China tiene 2 millones de víctimas.

La gripe es una enfermedad infecciosa difícil de contener porque está causada por cuatro

tipos diferentes de virus que pueden mutar rápidamente y causar nuevas epidemias.

La primera gran pandemia de gripe, llamada gripe rusa, se produce en 1889 y 1890 desde

las estepas euroasiáticas hasta toda Europa y tan lejos como el continente americano.

Pero es sobre todo la segunda pandemia de gripe, conocida como la gripe española, la

más devastadora, mientras la Primera Guerra Mundial aún está en marcha.

En los Estados Unidos, el virus muta y se vuelve muy virulento.

Transportada por soldados a Europa, la enfermedad se extiende por todo el mundo al final de

la Primera Guerra Mundial.

Un tercio de la población mundial está infectada, y alrededor de 50 millones de personas mueren

por ella.

En 1957, una nueva pandemia llamada Gripe Asiática comienza en el sudeste de China

y se extiende por el mundo desde Hong Kong.

En 1968, una cuarta pandemia reaparece en Hong Kong y mata a un millón de personas.

Originario de África central, han pasado alrededor de 60 años desde que el virus que causa el SIDA

se ha transmitido de los chimpancés a los humanos a través de la caza.

El virus se propagó entonces lentamente hasta llegar a Leopoldville en el Congo Belga, desde

donde se propagó siguiendo los ríos y los ferrocarriles.

Tras la independencia del país, el virus se extiende por todo el continente.

En 1964, el regreso de trabajadores haitianos contaminados la extiende a América del Norte,

en particular a los Estados Unidos en 1970.

En 1983, en París, el Instituto Pasteur identifica el virus del VIH que causa el SIDA, la enfermedad

debilita el sistema inmunológico y, por lo tanto, facilita el desarrollo de otras infecciones.

El SIDA se propaga entonces por el mundo hasta que es calificado como pandemia en 2005.

La prevención, el tratamiento y los anticonceptivos permiten frenar la enfermedad, que se ha cobrado

la vida de alrededor de 30 millones de personas en los últimos 30 años.

Hoy en día, unos 40 millones de personas viven con el VIH.

En noviembre de 2019, es probable que el virus SARS CoV 2 se transmite

de animales a humanos en Wuhan, China.

Aprovechando la globalización, la nueva enfermedad se propaga muy rápidamente, de modo que el

11 de marzo de 2020 la Organización Mundial de la Salud califica la epidemia de pandemia.

Además, a pesar de los grandes progresos de la medicina, otras enfermedades siguen

cobrando muchas víctimas.

La peste sigue siendo endémica y reaparece regularmente, la última epidemia en 2017

afectó a Madagascar y las Seychelles.

Desde 1961 una séptima pandemia de cólera está en curso, que todavía se cobra unas

100.000 víctimas cada año, según la OMS.

Actualmente hay poco menos de 3 millones de leprosos en el mundo, mientras que la gripe

estacional mata a unas 500.000 personas.

El paludismo o la malaria mata tantas personas cada año, la gran mayoría de ellas son niños

en el África subsahariana.

Las poblaciones pobres y remotas siguen siendo las principales víctimas de estas epidemias y pandemias.