A pandemic happens when an infectious and highly contagious epidemic disease affects every continent in the world.
Check out the 9 biggest epidemics and pandemics that marked history. The order chosen is in accordance with the most current (coronavirus), followed by those that most affected humanity.
1. Coronavirus
- Virus: SARS-COV-2
- Outbreak Period: 2019-2020
- Number of deaths: about 2.2 million people (February 2021)
Coronavirus is a pandemic that hit the world population at the end of 2019 and 2020. The given name "COVID-19" is the combination of the terms Corona, Virus and Disease (disease, in English), plus the year 2019.
It is worth remembering that the coronavirus is a family of viruses, and the cause of the disease COVID-19 is the virus identified as SARS-COV-2. The acronym SARS stands for Severe Acute Respiratory Syndrome.
The disease was identified at the end of 2019 in China, more precisely in the city of Wuhan, and has spread to other countries on all continents. This virus began to infect bats and later humans.
This disease attacks the lungs, leading patients to severe respiratory failure, which can result in death.
In the beginning, the illness includes the symptoms of a normal flu, but it can progress to cases of severe pneumonia. Note that the most affected people are over 60 years old.
2. Tuberculosis
- Bacterium: Koch's Bacillus
- Outbreak Period: 1850-1950
- number of deaths: about 1 billion people
It was in the mid-nineteenth century that tuberculosis began to affect a large part of the population. This disease caused by a bacterium, the bacillus of Koch, is also called pulmonary phthisis because it affects the lungs, causing severe symptoms of respiratory failure. However, the disease can also affect other organs of the body such as bones, skin and lymph nodes.
When affected by the disease, people begin to have bouts of acute coughing with blood and pus. Until the mid-twentieth century, tuberculosis affected people in different parts of the world and it is estimated that it killed about 1 billion individuals. Although controlled, it is still present in some countries around the world, especially the underdeveloped ones.
Understand more about this bacterial disease: Tuberculosis.
3. Smallpox
- Virus: Orthopoxvirus variolae
- Outbreak Period: 430 a. Ç. (first outbreak)
- Number of deaths: 300 million people approximately
Smallpox is a disease caused by the Orthopoxvirus variolae virus, with symptoms similar to those of normal flu (fever and body aches), plus vomiting and skin ulcers.
Several smallpox outbreaks have occurred in human history, the first of which occurred in 430 BC. Ç. in Greece. It is estimated that at that time ⅓ of the Greek population died.
Later, it was the turn of the Romans and with the great navigations in the 15th century, the disease arrived in America. It was only in the 18th century that the disease began to be controlled with the creation of the smallpox vaccine by Edward Jenner.
In the 20th century, more precisely in the 80s, when it killed more than 300 million people, this disease was considered eradicated from the planet.
Read more about this disease: Smallpox.
4. Spanish flu
- Virus: Influenza
- Outbreak Period: 1918-1920
- Number of deaths: between 20 and 40 million people
The Spanish flu was one of the biggest pandemics in history that hit the world population in 1918, at the end of the First World War and remained until 1920.
It got its name because Spain was one of the countries hardest hit at the beginning of the outbreak. Influenza is the name given to the virus of this disease that has infected around 500 million people worldwide.
The number of deaths is not certain, but it is estimated that this flu has killed between 20 and 40 million people worldwide. In Brazil, the country's president at the time, Rodrigues Alves, died. Note that a variation of this same virus, known as H1N1, returned to the population in 2009.
Read more about Spanish flu.
5. Black Plague
- Bacterium: Yersinia pestis
- Outbreak Period: 1347-1353
- Number of deaths: 25 million people approximately
It was in the 14th century, during the Middle Ages, that the Black Death, also called the bubonic plague, devastated the European and Asian population. It had its origin in the Orient, in Mongolia, and was spread by commercial ships that carried out work between the two continents.
Caused by bacteria, this disease first hit mice and then passed to humans by infected fleas that had bitten the animals.
The symptoms were similar to a bad flu, but with swelling of the lymph nodes and the presence of blisters of pus and blood throughout the body.
The biggest problem that made this disease reach great proportions was in the conditions of sanitation and hygiene at the time.
It is estimated that in Europe, ⅓ of the population died, that is, around 25 million people between the years 1347 and 1353.
Understand better about the history and characteristics of the disease:
- Black Death: what was it, summary, symptoms and mask
- Bubonic Plague: what it is, symptoms and transmission
6. AIDS (HIV)
- Virus: HIV
- disease outbreak: 1980
- Number of deaths: 20 million people approximately
AIDS, which stands for Acquired Immunodeficiency Syndrome (Acquired Immunodeficiency Syndrome), is a disease caused by the HIV virus that affects the immune system, attacking the T-CD4 lymphocytes, which are essential for the body's defenses.
Its transmission occurs during sexual intercourse, and also through blood transmission caused, above all, by the use of injectable drugs. In addition, pregnant women who have the virus can pass to their children during pregnancy.
To date, a cure for this disease has not been discovered. Patients control the disease and strengthen the immune system. It is estimated that more than 20 million people worldwide have died of AIDS.
Learn more about this disease: AIDS.
7. Typhus
- Bacterium: Rickettsia prowazekii
- Outbreak Period: 1918-1922
- Number of deaths: about 3 million people
It was in the 15th century that typhus began to reach the population, but it was after the first world war that this disease affects most people, killing about 3 million individuals in 5 years (1918 to 1922).
It is transmitted through contaminated lice, which were found in rats at the time. Therefore, this disease is also closely related to the Black Death, which also spread because of the lice that bit the rats and became infected.
With this, it is clear that typhus spread at a time when the sanitation it was one of the few concerns of the population. The symptoms of typhus are initially similar to those of flu, but with the presence of a rash.
8. Cholera
- Bacterium: Choleric vibrio
- Outbreak Period: 1817-1824
- Number of deaths: 30 thousand people approximately
Bacterial infectious disease that has had several outbreaks in human history, the largest of which occurred in the nineteenth century. It is estimated that around 30,000 people died from this disease.
Cholera is mainly caused by the lack of basic sanitation, generated by water and food contaminated by the bacteria.
The main symptom is diarrhea, leading the person to great dehydration. Currently, this disease still affects many people in the world, especially in underdeveloped countries, where sanitation is precarious.
Want to know more? See also the text about Cholera.
9. Swine Flu (H1N1)
- Virus: Influenza type A
- Outbreak Period: 2009-2010
- Number of deaths: about 20 thousand people
In 2009, the H1N1 flu, type A influenza or swine flu, started in Mexico and soon spread around the world. It was called swine flu as it was first identified in pigs.
The outbreak of this virus-caused respiratory disease lasted until 2010 and reached about 207 countries worldwide.
It is estimated that, in this period, 9,000 people died. The groups that present the greatest risk of contamination are children, pregnant women and the elderly.
Very contagious disease, it has symptoms similar to those of the common flu: fever, cough and body aches. It is estimated that around 20,000 people have died from this disease worldwide.
Learn more about The flu.
Also read about:
- Virus Diseases
- Diseases caused by bacteria
