History of Medicine Pandemics Part 3 - History of the most marking Pandemics.pdf

HISTORY OF MEDICINE AND PANDEMICS Dima Karam Fall 2022 These lectures offer insights into medicine’s past, ask what has shaped contemporary medicine, highlighting the evolution in medical theory, understandings of how the body works, how disease occurs and advances in treatment. The course will al...

HISTORY OF MEDICINE AND PANDEMICS Dima Karam Fall 2022 These lectures offer insights into medicine’s past, ask what has shaped contemporary medicine, highlighting the evolution in medical theory, understandings of how the body works, how disease occurs and advances in treatment. The course will also address essential medical breakthroughs so that you have a firm general grasp of major advances in the history of medicine. We will follow a chronological order to cover the following periods: Session 1: ★ classical antiquity ★ arab and medieval medicine Session 2: ★ early modern ★ 20th and 21st century medicine Session 3: ★ History of the most marking pandemics Learning outcomes On successfully completing the lectures you will be able to: 1. Understand and demonstrate the broad sweep of medicine’s development throughout history, and possess the skills needed to understand evaluate, contextualise and communicate effectively your knowledge of medical history. 2. Demonstrate knowledge in essential medical breakthroughs throughout history 3. Engage with the underlying issues associated with the evolution of how disease and health were understood throughout history, to gain an ability to evaluate and interpret these changes within their specific historical context 4. Be able to contextualise medical advances within the state of science at a particular period to be able to project what future developments may bring to the practice and project a physician’s role in that context History of the most marking pandemics Difference between outbreak, epidemic & pandemic Political terms not just medical Pandemics death toll History of Pandemics in a timeline Is Covid-19 still a pandemic? Difference between Pandemic, Epidemic, and Outbreak? ★ The World Health Organization declared COVID-19 a pandemic in March 2020. This was a landmark event. We heard a mix up of 3 important words every day: outbreak, epidemic and pandemic ★ Simply put, the difference between these three scenarios of disease spread is a matter of scale. Outbreak ★ Small, but unusual. By tracking diseases over time and geography, epidemiologists learn to predict how many cases of an illness should normally happen within a defined period of time, place and population. An outbreak is a noticeable, often small, increase over the expected number of cases. ★ Imagine an unusual spike in the number of children with diarrhea at a daycare. One or two sick kids might be normal in a typical week, but if 15 children in a daycare come down with diarrhea all at once, that is an outbreak. ★ When a new disease emerges, outbreaks are more noticeable since the anticipated number of illnesses caused by that disease was zero. Monkeypox is an example of an outbreak. Last June, Lebanon reported new hepatitis A outbreak in Tripoli. While disease is endemic to Lebanon, that outbreak was larger than normal. ★ When health authorities detect an outbreak, an investigation starts to determine exactly who is affected and how many have the disease. This information helps figure out how best to contain the outbreak and prevent additional illness. Epidemic ★ Bigger and spreading. ★ An epidemic is an outbreak over a larger geographic area. ★ When people in places outside of Wuhan began testing positive for infection with SARS-CoV-2, epidemiologists knew the outbreak was spreading, a likely sign that containment efforts were insufficient or came too late. ★ This was not unexpected, given that no treatment or vaccine was yet available. But widespread cases of COVID-19 across China meant that the Wuhan outbreak had grown to an epidemic.  Pandemic International and out of control. In the most classical sense, once an epidemic spreads to multiple countries or regions of the world, it is considered a pandemic. However, some epidemiologists classify a situation as a pandemic only once the disease is sustained in some of the newly affected regions through local transmission. To illustrate, a sick traveler with COVID-19 who returns to the U.S. from China doesn’t make a pandemic, but once they infect a few family members or friends, there’s some debate. If new local outbreaks ensue, epidemiologists will agree that efforts to control global spread have failed and refer to the emerging situation as a pandemic. Terms are political, not just medical ★ Epidemiologists are principally concerned with preventing disease, which may be fundamentally different than the broader concerns of governments or international health organizations. ★ The WHO has declared only two pandemics in history – for influenza in 1918 and for influenza H1N1 in 2009. For weeks, epidemiologists had been calling the coronavirus a pandemic. From an epidemiological perspective, the WHO’s declaration was overdue. In March 2020, the official numbers counted an excess of 120,000 cases in at least 114 countries. Eight countries, including the U.S., have more than 1,000 cases each, and community spread has been documented in several U.S. states. ★ Pandemic is the highest level of global health emergency and signifies widespread outbreaks affecting multiple regions of the world. However, the WHO statements remained hopeful that the pandemic can be controlled and the damage minimized by taking immediate aggressive steps.  Terms are political, not just medical ★ The formal declaration of COVID-19 or any other infectious disease as pandemic tells governments, agencies and aid organizations worldwide to shift efforts from containment (contact tracing, quarantine) to mitigation (social distancing, travel restrictions, hand hygiene, school closures). ★ It has economic, political and societal impacts on a global scale, and the WHO takes extreme care when making this determination. ★ It usually is a historical event. Pandemics: Death Toll: Highest to Lowest not updated. Pandemics: Death Toll as % of Population covid 19 is in the top 8.  Pandemics that changed history ★ So in the realm of infectious diseases, a pandemic is the worst case scenario. When an epidemic spreads beyond a country’s borders, that’s when the disease officially becomes a pandemic. ★ Communicable diseases existed since humankind’s hunter-gatherer days, but the shift to agrarian communities (cultivating land) 10,000 years ago increased the scale and spread of these diseases dramatically. It created communities that made epidemics more possible. ★ Widespread trade created new opportunities for human and animal interactions that sped up epidemics. ★ Malaria, tuberculosis, leprosy, influenza, smallpox and others first appeared during this period. ★ The more civilized humans became, with larger cities, more exotic trade routes, and increased contact with different populations of people, animals, and ecosystems – the more likely pandemics would occur.  Here are some of the major pandemics that have occurred over time: Name Time period Type / Pre-human host Death toll Antonine Plague 165-180 Believed to be either smallpox or 5M measles Japanese smallpox epidemic 735-737 Variola major virus 1M Plague of Justinian 541-542 Yersinia pestis bacteria / Rats, 30-50M fleas Black Death 1347-1351 Yersinia pestis bacteria / Rats, 200M fleas New World Smallpox Outbreak 1520 – onwards Variola major virus 56M Great Plague of London 1665 Yersinia pestis bacteria / Rats, 100,000 fleas Italian plague 1629-1631 Yersinia pestis bacteria / Rats, 1M fleas Cholera Pandemics 1-6 1817-1923 V. cholerae bacteria 1M+ Third Plague 1885 Yersinia pestis bacteria / Rats, 12M (China and India) fleas Yellow Fever Late 1800s Virus / Mosquitoes 100,000-150,000 (U.S.) Major pandemics that have occurred over time: Name Time period Type / Pre-human host Death toll Russian Flu 1889-1890 Believed to be H2N2 (avian 1M origin) Spanish Flu 1918-1919 H1N1 virus / Pigs 40-50M Asian Flu 1957-1958 H2N2 virus 1.1M Hong Kong Flu 1968-1970 H3N2 virus 1M HIV/AIDS 1981-present Virus / Chimpanzees 25-35M Swine Flu 2009-2010 H1N1 virus / Pigs 200,000 SARS 2002-2003 Coronavirus / Bats, Civets 770 Ebola 2014-2016 Ebolavirus / Wild animals 11,000 MERS 2015-Present Coronavirus / Bats, camels 850 COVID-19 2019-Present Coronavirus – Unknown 6.5M (Johns Hopkins University (possibly pangolins) estimate as of September 13, 2022) Timeline of ravaging pandemics: Despite the persistence of disease and pandemics throughout history, there’s one consistent trend over time – a gradual reduction in the death rate. Healthcare improvements and understanding the factors that incubate pandemics have been powerful tools in mitigating their impact. 430 B.C.: Athens The earliest recorded pandemic. The disease passed through Libya, Ethiopia and Egypt, to Greece. As much as two-thirds of the population died. The symptoms included fever, thirst, bloody throat and tongue, red skin and lesions. The disease, suspected to have been typhoid fever. 165 A.D.: Antonine Plague The Antonine plague was possibly an early appearance of smallpox throughout the Roman empire. Symptoms included fever, sore throat, diarrhea and, if the patient lived long enough, pus-filled sores. Timeline of ravaging pandemics: 541 A.D.: Justinian Plague First appearing in Egypt, the Justinian plague spread through Palestine and the Byzantine Empire, and then throughout the Mediterranean. The plague changed the course of the empire, caused massive economic struggle and is also credited with creating an apocalyptic atmosphere that spurred the rapid spread of Christianity. Recurrences over the next two centuries eventually killed about 50 million people, 26% of the world population. It is believed to be the first significant appearance of the bubonic plague, which features enlarged lymphatic gland and is carried by rats and spread by fleas. 11th Century: Leprosy Though it had been around for ages, leprosy grew into a pandemic in Europe in the Middle Ages, numerous leprosy-focused hospitals were built to accommodate the vast number of victims. A slow-developing bacterial disease that causes sores and deformities, can be fatal if not treated with antibiotics, leprosy was believed to be a punishment from God that ran in families.  Timeline of ravaging pandemics: 1350: The Black Death Responsible for the death of 1/3rd of the world population, this second large outbreak of the bubonic plague possibly started in Asia and moved west in caravans. Entering through Sicily in 1347 A.D. it spread throughout Europe rapidly. Dead bodies became so prevalent that many remained rotting on the ground and created a constant stench in cities. Killed 30-50% of europe’s population, took more than 200 years for the continent population to recover. 1492: The Columbian Exchange/Smallpox Following the arrival of the Spanish in the Caribbean, diseases such as smallpox, measles and bubonic plague were passed along to the native populations by the Europeans. With no previous exposure, these diseases devastated indigenous people, with as many as 90% dying throughout the north and south continents.In 1520, the Aztec Empire was destroyed by a smallpox infection. Research in 2019 even concluded that the deaths of some 56 million Native Americans in the 16th and 17th centuries, largely through disease, may have altered Earth’s climate as vegetation growth on previously tilled land drew more CO2 from the atmosphere and caused a cooling event.  Timeline of ravaging pandemics: 1500-1800: Smallpox In Europe, smallpox killed 400,000 people annually. The first ever vaccine was created to ward off smallpox at the end of th 18th c. 1855: The Third Plague Pandemic Starting in China and moving to India and Hong Kong, the bubonic plague claimed 15 million victims. Initially spread by fleas during a mining boom in Yunnan, the plague is considered a factor in the Parthay rebellion and the Taiping rebellion. India faced the most substantial casualties, and the epidemic was used as an excuse for repressive policies that sparked some revolt against the British. The pandemic was considered active until 1960 when cases dropped below a couple hundred. 1918: Spanish Flu The avian-borne flu caused in 50 million deaths worldwide, the 1918 flu was first observed in Europe, the United States and parts of Asia before swiftly spreading around the world (no universal consensus regarding where the virus originated). At the time, there were no effective drugs or vaccines to treat this killer flu strain. Wire service reports of a flu outbreak in Madrid in the spring of 1918 led to the pandemic being called the “Spanish flu.” The flu threat disappeared in the summer of 1919 when most of the infected had either developed immunities or died.  Timeline of ravaging pandemics: 1981: HIV/AID ★ First identified in 1981, highly infectious AIDS destroys a person’s immune system, resulting in eventual death by diseases that the body would usually fight off. ★ AIDS was first observed in American gay communities but is believed to have developed from a chimpanzee virus from West Africa in the 1920s. The disease, which spreads through certain body fluids, moved to Haiti in the 1960s, and then New York and San Francisco in the 1970s. ★ Treatments have been developed to slow the progress of the disease, but 35 million people worldwide have died of AIDS since its discovery, and a cure is yet to be found. 2003: SARS small impact on fatality but it helped by teaching how to keep other diseases under control. ★ First identified in 2003 after several months of cases, Severe Acute Respiratory Syndrome has possibly started with bats, spread to cats and then to humans in China, followed by 26 other countries, infecting 8,096 people, with 774 deaths. ★ Quarantine efforts proved effective and by July, the virus was contained and hasn’t re-appeared since. ★ SARS was seen by global health professionals as a wake-up call to improve outbreak responses, and lessons from the pandemic were used to keep diseases like H1N1, Ebola and Zika under control. Timeline of ravaging pandemics: COVID-19 2019: COVID-19 On March 11, 2020, the World Health Organization announced that the COVID-19 virus was officially a pandemic after barreling through 114 countries in three months and infecting over 118,000 people. And the spread wasn’t anywhere near finished. COVID-19 caused by SARS-CoV-2, a novel coronavirus strain had not been previously found in people. Symptoms include respiratory problems, fever and cough, and can lead to pneumonia and death. Like SARS, it’s spread through droplets in the air produced when an infected person coughs or sneezes. The 1st reported case in China appeared November 17, 2019, in the Hubei Province, but went unrecognized. Eight more cases appeared in December with researchers pointing to an unknown virus. Many learned about COVID-19 when Chinese ophthalmologist Dr. Li Wenliang defied government orders and released safety information to other doctors. The following day, China informed WHO and charged Li with a crime. Li died from COVID-19 just over a month later.  2019: COVID-19 The virus spread beyond Chinese borders to nearly every country in the world. By December 2020, it had infected more than 75 million people and led to more than 1.6 million deaths worldwide. Funding and political will in the United States and around the world accelerated the development of vaccines to fight the virus and by December 11, 2020, the FDA issued an Emergency Use Authorization for the use of the first COVID-19 vaccine. A week later the FDA approved a second, and by February 2021, Americans had access to three approved vaccines. By December 2021, 71% of the U.S. population had received at least one dose of a COVID-19 vaccine. Sept 2022: 68% of the world population has received at least one dose of a COVID-19 vaccine. Only 22.4% of people in low-income countries have received at least one dose. Lebanon: 50%, similar to Egypt, Cyprus by comparison 75%. 2019: COVID-19 The Omicron variant which emerged late last year causes less severe disease. Deaths from COVID-19 last week were the lowest since March 2020, as reported by WHO. On Sep 15th, the head of the WHO announced the world has never been in a better position to end the COVID-19 pandemic, his most optimistic outlook yet on the health crisis which has killed over six million people. "We are not there yet. But the end is in sight," That was the most upbeat assessment from the UN agency since it declared an international emergency in January 2020 and started describing COVID-19 as a pandemic three months later. Is Covid-19 still a pandemic? The WHO expects there to be future waves of infections, potentially at different time points throughout the world caused by different sub-variants of Omicron or even different variants of concern With over 1 million deaths this year alone, the pandemic remains an emergency globally and within most countries. The COVID-19 summer wave, driven by Omicron BA.4 and BA.5, showed that the pandemic is not yet over as the virus continues to circulate in Europe and beyond The WHO's next meeting of experts to decide whether the pandemic still represents a public health emergency of international concern is due in October. The U.S. health department is set to renew the status of COVID-19 as a public health emergency again in mid-October for what experts expect is the last time before it expires in January 2023. U.S. health officials have said that the pandemic is not over, but that new bivalent vaccines mark an important shift in the fight against the virus. They predict that a single annual vaccine like the flu shot should provide a high degree of protection and return the country closer to normalcy. Urbanization and spread of disease ★ Urbanization in the developing world is bringing more and more rural residents into denser neighborhoods, while population increases are putting greater pressure on the environment. As more people have moved to cities, population density, human encroachment and increased global interconnectivity have contributed to the spread of infectious diseases. ★ Air travel also has not only enhanced the interconnectedness of our world but has also accelerated the transmission of viruses and infectious diseases between cities. ★ When forests are cleared to make space for residential, commercial and agricultural purposes, habitats of a variety of animals are disturbed or destroyed. These human activities can bring us closer to isolated ecosystems which we wouldn’t necessarily have made contact with in the past, potentially exposing us to new pathogens that normally reside in animals and can then jump to humans. ★ 60% of reported emerging infectious diseases globally are zoonotic. Primates and bats have consistently been hosts for past viruses which have turned into epidemics and pandemics meaning they can also be vectors of future infectious diseases with pandemic potential. In order to manage this impending threat to global health, we need better understanding, surveillance and prevention of zoonotic diseases. Further readings: o End of COVID pandemic is 'in sight' -WHO chief: https://www.reuters.com/business/healthcare-pharmaceuticals/who-chief-says-en d-sight-covid-19-pandemic-2022-09-14/ o Pandemics That Changed History: https://www.history.com/topics/middle-ages/pandemics-timeline o Visualizing the History of Pandemics: https://www.visualcapitalist.com/history-of-pandemics-deadliest/ o Surviving a Pandemic, in 1918 https://daily.jstor.org/surviving-a-pandemic-in-1918/ o How the Plague Reshaped the World https://daily.jstor.org/how-the-plague-reshaped-the-world/ o The Origin of Quarantine https://daily.jstor.org/origin-of-quarantine/