Coronavirus vs. Other Pandemics: What’s the Difference?
Here’s how COVID-19 compares to other global outbreaks (and why it may be okay to worry a little less).
While we all stocked up on disinfectant and practiced social distancing, the World Health Organization (WHO) was busy declaring the fast-spreading novel coronavirus/COVID-19 a pandemic (a.k.a. an epidemic that has spread across countries and continents). But this kind of global outbreak is nothing new, say experts—since 1967 the world has experienced nine epidemics and pandemics that varied in severity and impact. Here’s how COVID-19 stacks up with each one.
But First, What Is a Pandemic?
Unlike an epidemic, a pandemic affects people worldwide. It is the result of a new virus or strain of viruses, so people have little (if any) immunity against it. It spreads quickly, and in addition to higher death numbers, causes a ton of social disruption, economic loss, and general hardship.
According to Rashid A. Chotani, M.D., a professor of epidemiology at the University of Nebraska Medical Center, while COVID-19 is causing disease in multiple countries, it has a very low “crude fatality rate”—approximately 3.52%—compared to previous outbreaks.
Crude fatality rate (CFR) is based on some math that involves factoring in the total cases and total deaths, which means COVID-19’s already low CFR will continue to drop as more cases are confirmed.
COVID-19 vs. Marburg (crude fatality rate: 80%)
Marburg virus was first detected in 1967 in the German city of Marburg, as well as Frankfurt, Germany and Belgrade, Serbia. The virus causes a severe type of illness called a haemorrhagic fever that can be accompanied by bleeding. Bats are considered natural carriers of the virus, but the first outbreak was tied to a lab working with African green monkeys. While both Marburg and coronavirus can cause a fever, coronavirus symptoms include cough and shortness of breath while Marburg symptoms include severe headache and malaise, and often some form of bleeding.
COVID-19 vs. Ebola (crude fatality rate: 40.40%)
The Ebola virus disease (EVD) first struck in 1976 and there have been occasional outbreaks in the decades since, primarily in Africa. In 2014, the virus killed over 11,000 people in West Africa.
While more lethal, Ebola is considered less contagious than coronavirus and is transmitted mainly by bodily fluids (coronavirus can be spread through droplets from coughs and sneezes).
COVID-19 vs. Hendra (crude fatality rate: 57%)
Hendra virus (HeV) originated in 1994 in Hendra, a suburb of Brisbane, Australia, after an outbreak of respiratory and neurologic diseases in horses and humans. Like coronavirus, it’s presumed that HeV’s natural reservoir (where it came from) was bats. The main difference between HeV and coronavirus is its spread—coronavirus is a global pandemic, while HeV didn’t move outside of Australia.
COVID-19 vs. H5N1/Bird Flu (crude fatality rate: 52.8%)
First identified in 1997, H5N1, otherwise known as “avian flu” or “bird flu,” is a type of influenza virus that causes a highly infectious, severe respiratory disease in birds. Human cases of H5N1 are rare and not very easy to transmit from person to person.
However, when a person does become infected, the mortality rate is high. Unlike coronavirus, which is easily spread between people, almost all cases of H5N1 infection in people have been associated with close contact with infected live or dead birds, or H5N1-contaminated environments.
COVID-19 vs. H7N9/Bird Flu (crude fatality rate: 39.3%)
While H7N9 is another type of avian influenza, this variety had never been seen in animals or humans until it was found in March 2013 in China. Unlike coronavirus, which is easily spread between humans, most cases of human infection with H7N9 virus have reported recent exposure to live poultry or potentially contaminated environments, like live animal markets.
This virus isn’t easily transmittable between people. The mortality rate is much higher than what’s been observed in COVID-19 and most other pandemics, but there has only been a total of 1,568 cases in three countries.
COVID-19 vs. Nipha (crude fatality rate: 77.6%)
Like several other major viruses, Nipha originated in bats (viruses that spread from animals to humans are called zoonotic viruses). But Nipha, which was identified in 1998, can also be transmitted through contaminated food or directly between people. Like coronavirus, Nipha can manifest as an asymptomatic infection in some people. However, in other cases, it can cause acute respiratory illness and fatal encephalitis (inflammation of the brain). Unlike coronavirus, which has spread globally, Nipha has caused only a few known outbreaks in Asia.
COVID-19 vs. SARS (crude fatality rate: 9.6%)
There was an outbreak of severe acute respiratory syndrome (SARS) in 2003 that resulted in more than 8,000 cases and 800 deaths. Also known as SARS-CoV, the infection has an 86% similarity with SARS-CoV-2, aka coronavirus. Both viruses likely originated in bats and the main transmission route is thought to be respiratory droplets.
Experts say, however, that despite the many similarities, the trajectory of the viruses looks different. Although 26 countries reported SARS cases in 2003, most were concentrated in five regions and were eventually eradicated through quick isolation of patients and strict quarantines. Coronavirus has impacted 96 countries and counting.
COVID-19 vs. H1N1/Swine Flu (crude fatality rate: 17.4%)
“Although swine flu does not typically affect humans, there was a pandemic in 2009–2010, the first flu pandemic in more than 40 years,” says Dr. Chotani. The illness was caused by a then-new flu virus known as H1N1 that was a combination of swine, avian (bird), and human genes that mixed together in pigs and spread to humans. The 2009 H1N1 pandemic caused over 284,000 deaths (201,200 respiratory deaths and another 83,300 deaths from cardiovascular disease) and sickened 1,632,258 people worldwide. Researchers at the CDC estimated that 80% of those who died from H1N1 were younger than 65, which is a contrast to coronavirus in which most deaths have occurred in people over 60, especially individuals who have a chronic disease.
COVID-19 vs. MERS-CoV (crude fatality rate: 34.4%)
Like SARS, the Middle East Respiratory Syndrome (MERS) coronavirus, COVID-19 is one of seven types of known human coronaviruses that has a zoonotic origin. Although MERS had a much higher mortality rate than SARS or COVID-19, there were significantly fewer cases of it during the outbreak in 2012 when it spread to 27 countries in Europe, Africa, Asia, and North America. However, it did not completely disappear like SARS and it appeared all year long with cases that peaked in the winter season.
How Bad Could Coronavirus Get?
“We do not have the full picture yet,” says Jan Carette, virologist and associate professor of microbiology and immunology at Stanford.
“The CFR is dependent on the total number of cases and the diagnostic kits are not readily available,” adds Dr. Chotani. A lot of cases are going undiagnosed, and while that might not exactly make you feel better, it does mean that we’re likely overestimating fatality. “Furthermore, based on the data from China, around 50% of COVID-19 cases are asymptomatic and 80% do not require medical intervention, with around 5% requiring hospitalization and 1% requiring intensive unit beds and ventilators,” says Dr. Chotani.
Italy and Coronavirus: BBC [March 10, 2020]. Coronavirus: Italy extends emergency measures nationwide.
Ebola History: CDC [n.d.] 40 Years of Ebola Virus Disease around the World. cdc.gov/vhf/ebola/history/chronology.html
Pandemic of 1918: CDC [March 20, 2019]. 1918 Pandemic (H1N1 virus). cdc.gov/flu/pandemic-resources/1918-pandemic-h1n1.html
Coronavirus Clinical Guidance: CDC [March 7, 2020]. Interim Clinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19). cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html
Public Health Practice: CDC [May 18, 2012]. Principles of Epidemiology in Public Health Practice, Third Edition, An Introduction to Applied Epidemiology and Biostatistics. cdc.gov/csels/dsepd/ss1978/lesson3/section3.html
About the Flu: CDC [June 11, 2019]: 2009 H1N1 Pandemic (H1N1pdm09 virus). cdc.gov/flu/pandemic-resources/2009-h1n1-pandemic.html
H1N1 Deaths: CIDRAP [Jun 27, 2012]. CDC estimate of global H1N1 pandemic deaths: 284,000. cidrap.
Marburg Bleeding and Fever: WHO [n.d.]. Marburg Haemorrhagic Fever.
Ebola Facts: WHO [February 10, 2020]. Ebola virus disease.
Human Animal Viruses: WHO [n.d.]. FAQs: H5N1 influenza.
Nipha Virus Info: WHO [n.d.]. Nipha virus infection.
Bird Flu Info: WHO [n.d.]. Avian influenza A(H7N9) virus.
COVID-19 Containment: Wilder-Smith, A. [March 5, 2020]. Can we contain the COVID-19 outbreak with the same measures as for SARS? The Lancet.