THE LARGEST PANDEMICS THROUGHOUT HISTORY AND ITS CONSEQUENCES

Fernando Alcoforado*

This article aims to present the great pandemics throughout history, pointing out how they originated, pointing out its origins and causes, the characteristic symptoms of the disease, its impact on society with the solutions adopted by medicine for its eradication, as well as the threats of new pandemics in the world such as around plague, measles and influenza, respiratory infections that are transmitted by birds and caused by unknown agents, the so-called “disease X” on the radar of WHO- World Health Organization, the possibility of an unprecedented microbe doing damage and, lastly, multi-resistant bacteria and fungi.

It is important to note three medical terms that define the spread of disease: outbreak, epidemic and pandemic. The WHO - World Health Organization defines as an outbreak the sudden appearance of a disease with a constancy higher than normal in a given region. An epidemic comprises a major outbreak that affects several regions of a municipality, a state or a country. A pandemic is the worst case. To receive this classification, it is necessary for an infectious disease to manifest globally, that is, on all continents.

The greatest pandemics throughout history like bubonic plague (1333), cholera (1817), tuberculosis (1850), smallpox (1896), Spanish flu (1918), HIV (1980), swine flu H1N1 (2009) and Coronavirus (2019), the threats of new pandemics in the world and the importance of vaccines to fight viruses and bacteria are described below:

1. Bubonic plague

Bubonic plague originated in Asia is caused by the bacterium Yersinia pestis, which was transmitted to people by infected mice and fleas. The disease is called bubonic plague because it is characterized by swelling of the lymph system ganglia, which are known as buboes, which are inflamed nodules that usually form in the groin after the flea leaves the rat and bites the human. Some symptoms appear before these rashes. They are: high fever, severe headaches and bodily pain, poor appetite, nausea and vomiting. Less common and more dangerous is pneumonic plague that occurs in patients who have already suffered from bubonic plague. It can be transmitted from person to person, by secretions and droplets in the air. There, it triggers severe pneumonia, which evolves fast. Among the signs are chest pain, difficulty breathing and coughing up blood. In the most severe version, septicemic plague, there is necrosis in the hands and feet. The risk of death is very high.

Bubonic plague arrived in Europe by ships arriving from Asia across the Mediterranean Sea. The initial condition for the establishment of the bubonic plague was the invasion of Europe by the Indian black rat (now rare). It is estimated that approximately 50 million to 100 million people died from 1333 to 1351, that is, about one third of the world population at the time. The world population did not return to pre-plague levels until the 17th century. The Bubonic plague or black plague has generated several religious, social and economic impacts and consequences, drastically affecting the course of European history. The enormous mortality caused a shortage of labor for landowners, causing the old feudal system, which forced people to work on a master's land to pay their rent, to start to collapse.

Bubonic plague continued to appear intermittently and on a small scale throughout Europe until it practically disappeared from the continent in the early 19th century. Assuming someone shows up at the hospital with symptoms of the plague, the first step is to isolate it completely. The disease - whether by breathing, by blood or by the secretion that comes out of the bubo - is quite contagious. The suspect patient must stay in a separate unit, and the professionals who will deal with him should wear special clothing, goggles and special masks that filter out small particles. Treatment is done with antibiotics, which are most effective if applied within 15 hours after symptoms appear. Prevention of the disease basically consists of the adoption of habits of hygiene and public health, which was quite precarious in Europe at the time when the pandemic occurred.

2. Cholera

The first global cholera epidemic occurred in 1817. Cholera is caused by an infection in the intestine caused by the bacterium vibrio cholerae. The bacteria causes the cells lining the intestine to produce a large amount of fluids that cause diarrhea and vomiting. The infection spreads when food or water is contaminated with feces or vomit from a person infected with the disease. The supply of contaminated water or food can cause massive outbreaks of the disease in a short period of time, especially in overcrowded areas, such as slums or refugee camps. The disease causes severe diarrhea in the individual, who dies of dehydration. The disease has had several other regional and global epidemics and has not yet been eradicated. According to the WHO (World Health Organization), from 100 to 120 thousand people die in the world every year contaminated by cholera. Treatment is based on antibiotics, as it is a bacterial disease, but its prevention is effective with access to basic sanitation.

3. Tuberculosis

Tuberculosis is an ancient disease of mankind, as signs of contamination have been found in skeletons more than seven thousand years old. The disease attacks the respiratory system and has claimed millions of victims worldwide. Tuberculosis is caused by the bacterium Mycobacterium tuberculosis, known as Koch's bacillus. The tuberculosis outbreak occurred from 1850 to 1950 and only started to be controlled after the discovery of the causative agent. Highly contagious, the disease is transmitted from person to person and, although it is currently considered to be controlled, it mainly affects poor countries. During the outbreak of tuberculosis, it is estimated that more than 1 billion people died from the disease. The cure came only when Alexander Fleming discovered penicillin in 1928.

4. Smallpox

Smallpox is a disease that has been present since antiquity in human history. Caused by the Orthopoxvirus variolae virus, the main symptoms are: fever, rashes in the throat, mouth and face. The risk of death from the disease is 30%, being higher in babies. It is estimated that from 1896 to 1980, more than 300 million people died from smallpox in the world. The colonization of the Americas at the end of the 15th century killed indigenous populations with smallpox transmitted by the colonizers as the biggest killer. Other deadly diseases resulting from the colonization of the Americas included measles, influenza, bubonic plague, malaria, diphtheria, typhus and cholera. A study by scientists at University College London, UK, showed that European expansion saw the population of the Americas drop from 60 million people (about 10% of the world population at the time) to just 5 or 6 million in a hundred years. The last case of the disease was registered in October 1977, which led the WHO to certify smallpox as eradicated in the 1980s. The eradication of the disease occurred as a result of a mass vaccination campaign that took place worldwide. The vaccine against the disease was discovered by Edward Jenner in 1796.

5. Spanish flu

Caused by the Influenza virus, Spanish flu spreads through the air. This epidemic at the beginning of the 20th century was called "Spanish Flu" because the outbreak started more intensely in Spain. However, the virus did not originate in Spanish lands. The theory most accepted by scholars on the subject is that the Spanish flu would have appeared in military training camps in the United States. That's because the first cases of the disease were also recorded there. Another element that reinforces that the Spanish flu appeared in the United States is that it spread throughout Europe shortly after American soldiers were sent to the war front in the First World War on that continent. Thus, the contact of contaminated soldiers with people in various places allowed the spread of the disease throughout Europe. It is estimated that more than 50 million people worldwide died from this pandemic. Some more alarmist estimates suggest that this number may have reached the total of 100 million dead. 1/3 of the world's population is believed to have been affected by the pandemic.

The Spanish flu spread in three waves of contagion between March 1918 and May 1919. Among these waves, the second, which started in August 1918, was the worst of them, as it was the most contagious, causing the death of millions of people. In the second wave of the disease, which occurred between August and December 1918, Asia, Africa, Central and South America were affected. The second wave of the spread of the Spanish flu made the situation alarming in several parts of the planet because the number of infected people soared and the symptoms registered became very serious, which contributed to the mortality rate to increase significantly. Those who became ill had fever, body pain, runny nose, cough, among other symptoms.

In the most severe cases, patients had severe respiratory problems, digestive and cardiovascular problems. Doctors sought to treat patients in the best possible way because medical knowledge at the time was still very limited. The doctors and scientists of the period did not know what caused the disease, as microscopes were unable to see the virus that caused Spanish flu. Microscopes could only observe bacteria, microorganisms larger than a virus. Some countries have failed to take the necessary preventive measures to combat Spanish flu and the result has been catastrophic.

The Spanish flu arrived in Brazil around September 1918 and spread to large centers, especially in Salvador, S?o Paulo and Rio de Janeiro. The city of S?o Paulo, for example, may have had up to 350 thousand infected people, which represented more than half of the population of the S?o Paulo capital, and a total of 5,331 people died. Rio de Janeiro - at the time the capital of Brazil - recorded about 12,700 deaths, which represented 1/3 of the total deaths in the country. Important personalities of the time were affected, such as Rodrigues Alves, elected president of the Republic in 1918, but he did not assume because he died. It is estimated that 35 thousand Brazilians died in this pandemic - among them, President Rodrigues Alves, in 1919.

The alarming number of cases of Spanish flu in Brazil meant that the Brazilian health system, which was not public, could not support the number of sick people. There was a lack of beds and doctors to attend to the number of sick people, making it necessary to improvise beds and hospitals to care for people. To prevent the disease from spreading further, the order of the authorities was to order the closure of bars, factories, schools, theaters, etc. The number of deaths in a short time also exceeded the burial capacity that local cemeteries could carry out. There were not enough coffins and the gravediggers worked frantically. Even the removal of people from work was ordered to prevent the spread of Spanish flu. In Rio de Janeiro, the Congress and the Senate were closed and, in Salvador, the local press reflected the spread of the disease throughout the city. This resulted in the banning of some public services, as well as a ban on the holding of public events, including festivities and religious services

As there was no way to cure the disease - the doctors used some medications to alleviate the symptoms and wait for the patient's body to react. The authorities' recommendations were for people to avoid crowds, wash their hands frequently and avoid physical contact. As Influenza is a virus that is constantly changing, there is no completely effective treatment for it. However, there are flu vaccines that prevent a new outbreak of Spanish flu.

6. HIV

HIV (Human Immunodeficiency Virus) was declared pandemic after 1980, when the first cases emerged. The virus leads to the occurrence of AIDS (Acquired Immunodeficiency Syndrome) and attacks the immune system, responsible for defending the body from infections and diseases. Considered an STI (Sexually Transmitted Infection), HIV is transmitted through blood, sperm, vaginal discharge and breast milk contaminated with the virus. Despite starting more than 30 years ago, the HIV pandemic has not yet been closed, as the disease is recurrent in many regions of the world. This fact can be explained because a cure for the disease has not yet been discovered.

Since the beginning of the pandemic, it is estimated that more than 22 million people have died from illnesses and complications caused by AIDS, such as tuberculosis and infections. Although there is still no cure for HIV, current treatment is highly effective and can even lower the viral load to undetectable levels, which contributes to the life expectancy of a person with HIV being similar to that of a person who don't have the disease.

7. Swine Flu - H1N1

This epidemic was caused by a mutation of the Influenza virus that until then inhabited only pigs, also affecting humans. For this reason, it was given the name "Swine Flu". This epidemic spread around the world in a few days, bringing symptoms similar to those of a strong flu. Between 2009 and 2010, it is estimated that 17 to 18 thousand people died worldwide as a result of this epidemic, which would have started to spread in Mexico. Many people died about 48 hours after the first symptoms. The discovery of vaccines against the virus prevented further outbreaks from occurring. However, the virus continues to mutate and affect people in isolation worldwide.

8. Coronavirus

Coronaviruses are a viral family known to science since the 1960s, responsible for causing mild respiratory infections in humans and animals. In December 2019, a new modality of these viruses began to spread very quickly from China, causing a global pandemic. This virus spreads very quickly and causes death mainly among people considered to be at risk - elderly, people with respiratory diseases, diabetics, heart and other chronic diseases.

To date, there are more than 1.5 million confirmed cases and 88,982 deaths worldwide (04/09/2020). In Brazil, there are 25,262 infected and 1,532 deaths (04/14/2020). Brazil, as well as several countries, has adopted measures to restrict the movement of people. Quarantine covers the closing of shops and public offices, suspension of classes and closing of borders. According to experts, social isolation is the best measure to stop the spread of the virus.

What are the similarities between Coronavirus and other pandemics of the past? The greatest similarity of Coronavirus is with the Spanish flu, whose measures adopted at the beginning of the 20th century were similar to those currently being adopted in the fight against Coronavirus. At that time, the increasing number of Spanish flu cases in Brazil caused the Brazilian health system, which was not public, to collapse. There was a lack of beds and doctors to attend to the number of sick people, making it necessary to improvise beds and hospitals to care for people. To prevent the disease from spreading further, the order of the authorities was to determine the use of masks and the closure of bars, factories, schools, theaters, etc. The number of deaths in a short time also exceeded the burial capacity that local cemeteries could carry out. It is this scenario that seeks to prevent it from occurring at the moment in Brazil with Coronavirus with the imperative need for social isolation recommended by the WHO - World Health Organization.

In the 14th century, the bubonic plague or black plague generated a panic in the population much like what we are now experiencing with Coronavirus. People were isolated, no one took to the streets, afraid to come into contact with miasmas, poisonous gases that are supposed to be behind the disease. The most optimistic estimates suggest that an immunizer or vaccine against Coronavirus will be available within 18 or 24 months. This should be the solution to this problem in the long run. Until the emergence of the vaccine that would act in prevention and a drug that is able to cure the Coronavirus patient, the population must wear masks if they go out on the streets and maintain total social isolation.

9. The threat of new pandemics in the world

Experts point out that there are other threats of pandemics such as the return of the bubonic plague, especially in countries lacking basic sanitation and with poor public cleaning services and the measles that returned after being eradicated in the world. The bubonic plague can again become a pandemic. The WHO came to classify it as a reemerging infection in 2018, after registering 3,248 cases worldwide between 2010 and 2015, with 584 deaths. The WHO warned that the number could be higher, as there is a tendency of underreporting and animals that carry Yersinia pestis that exist on all continents, except for Oceania. In Brazil, the last record of bubonic plague in humans is 2005. However, as the infection persists in wild rodents, plague should be considered a “potential danger”, according to the Ministry of Health. In Brazil, there are two natural foci of the bubonic plague bacteria: the Northeast region and the municipality of Teresópolis, in Rio de Janeiro. Even the United States handles occasional cases. In 2015, there were 11, with three deaths.

Another virus that must be monitored constantly is influenza, responsible for the flu that undergoes important mutations frequently and, each one, has the potential to create a new epidemic until the immune system learns to defend itself. This is one of the reasons why the composition of influenza vaccines changes annually. There are also respiratory infections that are transmitted by birds and caused by unknown agents. The WHO even has a category called “disease X” on its radar. It serves to alert health professionals about the possibility of an unprecedented microbe doing damage. Finally, multi-resistant bacteria and fungi. These are a very serious problem that has been increasing.

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* Fernando Alcoforado, 80, awarded the medal of Engineering Merit of the CONFEA / CREA System, member of the Bahia Academy of Education, engineer and doctor in Territorial Planning and Regional Development by the University of Barcelona, university professor and consultant in the areas of strategic planning, business planning, regional planning and planning of energy systems, is author of the books Globaliza??o (Editora Nobel, S?o Paulo, 1997), De Collor a FHC- O Brasil e a Nova (Des)ordem Mundial (Editora Nobel, S?o Paulo, 1998), Um Projeto para o Brasil (Editora Nobel, S?o Paulo, 2000), Os condicionantes do desenvolvimento do Estado da Bahia (Tese de doutorado. Universidade de Barcelona,https://www.tesisenred.net/handle/10803/1944, 2003), Globaliza??o e Desenvolvimento (Editora Nobel, S?o Paulo, 2006), Bahia- Desenvolvimento do Século XVI ao Século XX e Objetivos Estratégicos na Era Contemporanea (EGBA, Salvador, 2008), The Necessary Conditions of the Economic and Social Development- The Case of the State of Bahia (VDM Verlag Dr. Müller Aktiengesellschaft & Co. KG, Saarbrücken, Germany, 2010), Aquecimento Global e Catástrofe Planetária (Viena- Editora e Gráfica, Santa Cruz do Rio Pardo, S?o Paulo, 2010), Amaz?nia Sustentável- Para o progresso do Brasil e combate ao aquecimento global (Viena- Editora e Gráfica, Santa Cruz do Rio Pardo, S?o Paulo, 2011), Os Fatores Condicionantes do Desenvolvimento Econ?mico e Social (Editora CRV, Curitiba, 2012), Energia no Mundo e no Brasil- Energia e Mudan?a Climática Catastrófica no Século XXI (Editora CRV, Curitiba, 2015), As Grandes Revolu??es Científicas, Econ?micas e Sociais que Mudaram o Mundo (Editora CRV, Curitiba, 2016), A Inven??o de um novo Brasil (Editora CRV, Curitiba, 2017), Esquerda x Direita e a sua convergência (Associa??o Baiana de Imprensa, Salvador, 2018, em co-autoria) and Como inventar o futuro para mudar o mundo (Editora CRV, Curitiba, 2019).