Previous pandemics declared by World Health Organisation (WHO) since the 20th Century (info graphic)
Pandemics of the 21st century
Swine flu (2009-2010)
The pandemic was caused by an H1N1 virus strain. In March 2009, the virus was found to be transmitted among people fast. This resulted in respiratory infections with mild to severe symptoms. The initial cases were reported in Southern California, USA. The virus, which was a subtype of swine influenza virus, spread over the course of one year across the globe. The Centre for Disease Control and Prevention (CDC), USA, Department of Health and Human Services, estimated that around 60.8 million cases were reported and around 12469 people died in the US because of the H1N1 virus. Additionally, they estimated that 151700-575400 people died due to it during the first year.
Covid-19 (2019-till date)
The novel coronavirus (SARS-COV-2) causes severe respiratory disorders transmitting the disease now called Covid-19. In December 2019, the virus was first noticed in the Wuhan city of China. Wuhan is one of the most significant locations in China from where the country’s import and export business is controlled. Soon the virus spread to Italy, Spain, Iran, and the USA. Till date, more than 4,155,288 cases have been reported and around 282,780 patients have died worldwide. The pandemic has also led to a terrible financial crisis as most of the countries affected by the virus had to call for lockdown leading to sudden closure of major sectors and industries.
Pandemics of the 20th century
Spanish Flu (1918-1919)
Spanish Flu was caused due to the H1N1 influenza A virus that infected 500 million people, which was around one-third of the world’s population. The CDC also estimated that the death toll was about 50 million worldwide. From Europe to the US, the flu wreaked havoc over the world’s economy just after the First World War ended. A delayed circulation of information and consciousness regarding the disease is considered to be responsible for that stage of transmission. The first wave of Spanish Flu was mild but the second wave reacted quite fatally, killing the infected body within few hours to days. The virus after generating symptoms of the skin turning blue and the ungs filling up with fluid, suffocated the patients to death.
Asian Flu (1957-1958)
During the initial days of 1957, in East Asia an H2N2 influenza A virus emerged causing the Asian Flu that later spread across the globe. According to the CDC, the virus ended its deadly global march killing 1.1 million people worldwide. The virus emerged in Guizhou, China, originating from mutation in wild ducks combining with a pre-existing human strain. Rheumatic heart disease was the most troubling factor of Asian Flu. The pandemic took almost a decade to disappear completely remaining as an epidemic after 1958. But it was a pandemic that experienced the first opportunity to observe vaccination.
Hong Kong Flu (1968)
A new influenza H3N2 virus rang the alarm in Hong Kong only 10 years agter the Asian Flu. People aged more than 60 years were mostly affected by the virus. As per the CDC, the number of deaths due to this was around 1 million across the globe including about 1, 00,000 deaths in the USA. The virus differed from the Asian Flu virus by the HA antigen, however, it retained the same NA antigen (N2). Due to the similar antigen, the virus was recognised by mankind’s immunity system that could produce antibodies as an immune response. The virus still transmits worldwide as a seasonal influenza A virus.
Information sources: The World Health Organisation (WHO) and the Centre for Disease Control and Prevention (CDC), USA, Department of Health and Human Services.
- Compiled by Kuntala Sarkar