Global pandemic COVID – 19 is pulling the brakes on the entire planet. In the face of it, the whole world is consistently experiencing rocketed numbers of daily cases and deaths, lock downed towns, collapsing economies, etc.
What is a pandemic?
We have witnessed how Wuhan’s novel coronavirus outbreak has transformed itself into a deadly contagious pandemic within a couple of months. After considering its severity and alarming levels of spread, WHO characterized COVID-19 as a pandemic on 11th March 2020. What makes pandemic differ from an outbreak or epidemic? In simpler words, terms outbreak, epidemic and pandemic denote the transitional states of an infectious disease based upon its severity. “Outbreak” is referred to as the sudden rise of infected cases beyond the anticipated level. The term “epidemic” stands when an outbreak reaches to a status where a large number of individuals in a community or geographical region become affected. When the infection exceeds the territorial margins and begins to spread over multiple countries it is given the name “pandemic” to indicate the global threat.
History of early pandemics in a nutshell
Since the prehistoric days, plagues and pandemics have functioned as key stressors in shaping human civilizations. In the ancient world, as the human civilizations expanded, infectious outbursts have occurred from time to time. With the widened land and maritime trade routes, interactions between different ethnic communities were flourished, paving the way for infectious diseases to sweep through all accessible corners of the planet becoming pandemics. The first recorded pandemic in the history runs back to 430 B. C during the “Peloponnesian war” where Spartans laid siege on Athenian walls. From then onwards, pages of history books are filled with long lists of pandemics that hammered humanity ruthlessly. Fallen empires, shifted capitals and abandoned townships, ignited riots and rivalries; throughout the historical timescale, pandemics have always altered the way of life in humans.
Even in a summary about early pandemics, the name “Yersinia pestis” can never be pass unmentioned. This single bacterium species is responsible for life losses than any civil war or natural disaster could account for. Although there were several recurring outbreaks caused by this bacterium, Justinian plague and Black death were the most outrageous pandemics. Justinian plague (541 – 542 A.D.) which marked the decline of mighty Byzantine empire, is considered as the first significant outbreak of bubonic plague accounting for deaths between 30 – 50 million. The second outbreak of bubonic plague, “Black death” (1346 -1353) converted the European continent into a mass graveyard and wiped out nearly one third to half of the world’s population. Its gigantic death toll of nearly 200 million is ranked first in the history of pandemics
Major pandemics in the last century
A quick glance to recent past can point out a few major pandemics. Three out of it is influenza pandemics occurred between the intervals of several decades.
Spanish flu (1918 – 1920)
Recorded as the first and worst pandemic of the 20th century. It was caused by an A(H1N1) virus. Spanish flu infected 500 million people, nearly one-third of the world’s population. According to the past reports high mortality rates were observed in individuals of the age groups lower than 5 years, between 20 -40 years and 65 years or above. Absence of an effective drug or vaccine against the viral strain triggered the death toll up to 50 million. Control efforts of the virus was limited to non-pharmaceutical interventions such as isolation, quarantine, use of disinfection etc.
Asian flu (1957 – 1958)
Asian flu pandemic was the second major influenza pandemic to occur within the 20th century. It is believed to be originated in the East Asia region and expanded to the world subsequently. A virus named as influenza A subtype H2N2 was the causative agent of this pandemic which was originating from strains of avian influenza and human influenza viruses. In comparison to Spanish flu, this particular pandemic was mild and accounted for 1.1 million deaths worldwide. Availability of antibiotics to treat secondary infections and development of a vaccine against H2N2, assisted in pulling down the pandemic.
Hong Kong flu (1968 – 1970)
The third global outbreak of influenza pandemic was initiated by the subtype H3N2 of the influenza A virus. It is suspected that virus H3N2 evolved from the strain of the H2N2 virus that gave rise to Asian flu pandemic through the process called antigenic shift. Even though the infection was mild in terms of past pandemics it was highly contagious and claimed about 1 to 4 million lives.
HIV (1981 – till present)
Acquired immune deficiency syndrome (AIDS) was first identified in 1981 as an infection caused by HIV. It transmits through contaminated body fluids and destroys one’s immune system leading to eventual death. AIDS developed into a pandemic at the end of the 20th century and since then it is accounted for about 32 million deaths.
Swine flu (2009 – 2010)
Categorized as another influenza pandemic, Swine flu happened to be the first pandemic of the 21st century. It was caused by a new strain of H1N1 originated in Mexico. Unlike many other pandemics, swine flu susceptible group excluded elderly people, posing threat predominantly on individuals below 65 years. For this pandemic, the death toll was limited between 151,700 and 575,400 owing to an effectively developed vaccine.
History repeats in novel pathways. In the history of humanity, this is our first encounter with a pandemic sparked by coronavirus. Although SARS and MERS were initiated from the same family of coronavirus they were efficiently contained, and pandemic status was kept at bay. Unfortunately, up to date we are weaponless against COVID -19. Although our death toll is below the count of many pandemics it is still ongoing and expected to project further. Until an effective vaccine emerge, we are left with old day control practices such as isolation, quarantine and use of disinfection to fight the virus.
Story credits
https://www.livescience.com/worst-epidemics-and-pandemics-in-history.html
https://www.visualcapitalist.com/history-of-pandemics-deadliest/
https://www.who.int/emergencies/diseases/novel-coronavirus-2019/events-as-they-happen
https://www.cdc.gov/flu/pandemic-resources/1918-pandemic-h1n1.html
https://www.britannica.com/event/Asian-flu-of-1957
https://www.history.com/topics/middle-ages/pandemics-timeline
