Pandemics: Recent Past
- Dr Jyoti Jalan
- Jun 7, 2020
- 5 min read
Updated: Jul 23, 2024
It takes just one person to start an outbreak, further risking a pandemic.
A viral trend is anything that makes everyone talk about it at a given time, be it a hairstyle, a handbag, a dance video, or a hashtag. The worst thing to go viral, no doubt, is a pandemic disease. Humans have long dealt with disease outbreaks, some of which even brought their villages on the verge of extinction. While we are at the center of COVID-19 pandemic (the viral virus) currently, here’s a brief on the extent of other pandemics that have occurred over the last century.
1. Spanish Flu - 1918-1920
Recently marking its 100th anniversary, the 1918–19 influenza pandemic was the most devastating epidemic in modern history, infecting about one-third world population.
Cause: influenza A subtype virus H1N1
Cases: ~500 million
Deaths: ~50 million worldwide
Place of Origin: NOT Spain. And there is no universal consensus on the place of origin. As Spain was a neutral zone during World War I and had a more liberal media, the early and accurate accounts of flu outbreak were first reported in Spain, and with that the nickname “Spanish Flu” adhered. Spread: 1918 was the year of World War I still being at large and also of its end. So, despite the limited transport services then, the massive troop movements and overcrowding accelerated the spread.
Factors that contributed to the enhanced lethality:
Limited medical technology, with no intensive care support and mechanical ventilation, and non-existing diagnostic tests for influenza infection. In fact, doctors and scientists had little to no knowledge of real agents of influenza.
At the time, there was no vaccine against influenza. Moreover, antibiotics and antiviral drugs were not developed by then (Penicillin was discovered in 1928, and the first antiviral drug came into clinical use in the 1960s).
Healthcare plans were also finite, with no coordinated pandemic management planning.
Many influenza deaths were caused by complicating secondary bacterial pneumonia.
A unique feature: Higher than expected mortality in the healthy young adult group (20-40years) was a contrasting characteristic of this pandemic. Although the exact reason remains unexplained, some of the hypotheses include:- an overactive immune system (cytokine storm) damaging the body's own cells while fighting the virus; dysregulated immune responses increased the susceptibility to secondary bacterial pneumonia.
Intervention: mostly non-pharmaceutical such as good personal hygiene, use of disinfectants, quarantine, and less social gatherings. However, the overall application was uneven. (We understand this too well right now, don’t we?)
2. Asian Flu - 1957-1958
First identified in China, Asian flu was caused by the H2N2 strain which was a recombination of avian influenza and human influenza viruses.
Cause: influenza A subtype virus H2N2
Cases: ~500 million
Deaths: ~2-4 million
Place of Origin: Guizhou, China
Spread: In the first 3 months of its first appearance, it had disseminated in various parts of Asia, including Hong Kong, Singapore, India, and Taiwan, later on reaching the UK and the US.
Around 3% of cases had secondary complications with pneumonia and bronchitis, with a 0.2% mortality.
Intervention: The swift development of a vaccine against the H2N2 virus by Dr. Maurice Hilleman, improved medical facilities, and the presence of antibiotics to treat secondary infections controlled the spread and mortality rate significantly.
3. Hong Kong Flu - 1968-1970
Descending from the strains of H2N2 virus of 1957, the H3N2 viruses have evolved rapidly and become the leading cause of seasonal influenza illness in the last 50 years.
Cause: influenza A subtype virus H3N2
Cases: ~400 million
Deaths: ~1 million
Place of Origin: Hong Kong
Spread: After the first reported case in Hongkong, it only took 17 days before the outbreak of flu was reported in Singapore. And in the next 3 months, it had spread across South Asia, Europe, Australia, and the US. This pandemic circulated in two waves between 1968-1970.
It carried a low death rate of 0.5%; a large part of the population that had gone through the Asian flu in 1957 had gained some immunity against the N2 virus.
Intervention: This pandemic that took place exactly after 50 years of Spanish flu, was managed efficiently owing to substantial medical care advancements, vaccination, the advent of antiviral medications, and the treatment of secondary infections with even more effective antibiotics.
4. Swine Flu - 2009-2010
Since the second appearance of the H1N1 virus in 2009 as swine flu (first being in 1918 as Spanish flu), the H1N1 virus has become one of the common circulating seasonal influenza viruses requiring vaccination.
Cause: influenza A subtype virus H1N1
Cases: ~700 million
Deaths: >200,000
Place of Origin: Veracruz, Mexico
Spread: Swine flu started in Mexico in March 2009 and was declared as a pandemic by WHO on June 11, 2009. Within a year, the new strain of the H1N1 virus had spread rapidly, in two waves, and infected 700 million to 1 billion people with swine flu across the globe.
The flu infected 11-21% of the world population with a 0.03% fatality rate. Uncomplicated cases exhibited similar symptoms as that of seasonal flu. Pulmonary complications were more commonly seen in individuals with already underlying respiratory conditions and obesity.
Unlike seasonal influenza, the 2009 pandemic affected the younger age group more. This feature exhibits similarity to the 1918-19 H1N1 illness.
Intervention: Antiviral drugs (Oseltamivir or Zanamivir) were prescribed to people with flu symptoms and the at-risk groups. By November 2019, more than 65 million doses of pandemic H1N1 vaccination were administered across the globe, preventing millions of illnesses. A vaccine against H1N1 is now included in the annual flu vaccination.
Preparedness : Undoubtedly, there has been a significant reduction in the death rates with every pandemic and epidemics over the years. Credit goes to the highly active healthcare sector and the brilliant technological experts who together as a force continue to ameliorate lives through advanced medical equipment & pharmaceuticals, comprehensive data collections & researches, and awareness via information & communication. Nevertheless, with an increasing world population and the introduction of novel viruses like Covid-19, the risk of exposure remains high and overall impact unpredictable.
Extras:
Both Spanish flu (1918) and Hong Kong flu (1968) likely originated in China according to several research journals. However, there is no certainty about this.
2009- along with being the year of the swine flu pandemic, also brought many epidemics such as Cholera in Zimbabwe, Dengue fever in Bolivia, Gujarat Hepatitis B outbreak in India, and meningitis in West Africa.
Smallpox- killed more than 500 million in its last 100 years of existence(1877-1977) before being certified as 'globally eradicated' in 1980.
HIV/AIDS- since the beginning of this ‘global epidemic’, 75 million people have been infected, and 32 million have died so far.
References:
Comments