Difference Between an Epidemic and a Pandemic
What is an Epidemic?
An epidemic is defined as an outbreak of disease that spreads quickly and affects many individuals at the same time.A disease can be declared an epidemic when it spreads over a wide area and many individuals are taken ill at the same time.If the spread escalates further, an epidemic can become a pandemic, which affects an even wider geographical area and a significant portion of the population becomes affected.
What is a Pandemic?
A pandemic is a type of epidemic (one with greater range and coverage), an outbreak of a disease that occurs over a wide geographic area and affects an exceptionally high proportion of the population. While a pandemic may be characterized as a type of epidemic, you would not say that an epidemic is a type of pandemic.
What to know about Epidemic
Epidemic, which may be traced to the Greek epidḗmios (“within the country, among the people, prevalent (of a disease)”), may carry broader meanings, such as “excessively prevalent,” “contagious,” or “characterized by very widespread growth or extent” (often used in a non-medical sense).
Epidemics happen frequently, but many people aren’t familiar with them unless they’re directly affecting their home region, Trivedi says. A few examples of epidemics include:
- The Zika virus outbreak that occurred in 2016 and 2017. Zika is spread by mosquitoes in tropical areas and in travelers returning from those areas. Although most people have mild or no symptoms when they contract Zika, the virus can cause microcephaly, a serious birth defect, in women who are pregnant. In 2016, there were 5,168 cases with symptoms reported in the U.S., according to the CDC. By 2019, there were only 19 reported cases in the U.S.
- The Ebola outbreak that occurred in 2014 to 2016 in West Africa was the largest outbreak of the disease, the World Health Organization reports. (The Ebola virus was originally discovered in 1976 in what is now the Democratic Republic of Congo.) The 2014 to 2016 epidemic began in Guinea and moved to Sierra Leone and Liberia. There also was an outbreak in the Democratic Republic of Congo in 2018/2019. Ebola can frequently kill if it’s not treated. A total of 28,600 cases and 11,325 deaths took place from Ebola in 2014 to 2016, the CDC reports.
- The severe acute respiratory syndrome (SARS) virus that spread in Asia beginning in 2003 was an epidemic. SARS is part of the coronavirus family of diseases. Around the world, 8,098 people became sick from SARS and 774 died. Although SARS did spread outside of Asia, it was associated with travel from the affected countries.
- Flu epidemics. Some areas of the U.S. (or other countries) may experience a flu epidemic if the number of cases rises beyond the norm. Trivedi’s hospital did not experience a flu epidemic this most recent flu season, but they did see a rise in cases – by as much as 2% during one week alone in January. Among those with the flu, 73% had not received a flu vaccine. “That’s not an epidemic, but it became larger scale,” Trivedi says. “It could become an epidemic.” Epidemics can be avoided when people practice safe hygiene such as washing their hands and staying home when sick.
For an epidemic to stop, the number of cases needs to go down. This is often tied into stopping how it’s transmitted.
What to know about Pandemic
Pandemic is less often encountered in a broad and non-medical sense, but does have additional senses, including “affecting the majority of people in a country or a number of countries”, “found in most parts of the world and in varied ecological conditions,” and “of or relating to common or sensual love” (in this last sense the word is usually capitalized). Pandemic comes from the Greek pandēmos (“of all the people”), which itself is from pan- (“all, every”) and dēmos (“people”)
Before a disease becomes a pandemic, it has to reach a few other levels, says Rodney Rohde, who is an honorary professor of international studies and associate director for the Translational Health Research Initiative at Texas State University in San Marcos, Texas.
Here are those levels, in increasing severity, according to the CDC:
- Sporadic, used to describe when a disease is happening infrequently and irregularly.
- Endemic, or something that’s a constant presence in a geographic area. For instance, there are tropical parts of the world where the mosquito-borne infection malaria is endemic.
- Epidemic, which is a sudden increase in the number of cases and is more than what’s expected for an area.
- Finally, there’s pandemic, such as COVID-19.
Some previous examples of pandemics include:
- The Spanish flu (H1N1 virus) of 1918. (Fans of the “Twilight” series may remember that Edward Cullen almost died during the Spanish influenza pandemic.) About 500 million people – a third of the population around the globe – were sick from the Spanish flu. A total of 50 million people or more died from it around the world, according to the CDC. The first people identified with it in the U.S. were military personnel.
- In 1968, there was a pandemic caused by an influenza A (H3N2) virus that killed a million people worldwide, including 100,000 in the U.S. There have been other flu pandemics in the past century, including the H1N1 pandemic in 2009. Although the WHO declared an end to the H1N1 pandemic in August 2010, the virus still circulates seasonally during flu season.
A pandemic may sound scarier than an epidemic, but it all depends on where you live. “A pandemic is more concerning for the world, but if you live where there is an epidemic going on, that’s just as concerning for you,” says Dr. Shira Doron, hospital epidemiologist at Tufts Medical Center and an associate professor at Tufts University in Boston.
You also may be concerned about both an epidemic and a pandemic if you live with a pre-existing condition, such as diabetes or COPD, that could make you more vulnerable to get a contagious infection.
Just like with an epidemic, a pandemic is over when the high number of cases diminishes. Making the decision to say that a pandemic is no longer present can be difficult. “I empathize with the WHO, CDC and others who are working during difficult times while trying to hit a constantly moving target,” Rohde says.
Is Coronavirus said to be an Epidemic or Pandemic?
COVID-19 is now a pandemic, as WHO director-general Tedros Adhanom Ghebreyesus declared during a media briefing on Wednesday, March 11. The decision to declare a pandemic is not one made lightly, Ghebreyesus added.
As of March 12, there are more than 118,000 cases in 114 countries; and nearly 4,613 people have died from it, according to the WHO. More than 90% of the cases are in four countries – China, South Korea, Italy and Iran – two of which (China and South Korea) have declining numbers of cases. There are 77 countries with no cases; 55 countries have 10 cases or less.
On Monday, March 9, Ghebreyesus said that the threat of a pandemic was “very real,” but had not yet called it a pandemic.
Decisions made by governments, businesses, communities, families and individuals can change and influence what happens with the new coronavirus disease, he adds. “If countries detect, test, treat, isolate, trace and mobilize their people in the response, those with a handful of cases can prevent those cases (from) becoming clusters, and those clusters (from) becoming community transmission,” Ghebreyesus says.
Doron echoes some of Ghebreyesus’s sentiments. “Referring to this epidemic as a pandemic should not be interpreted as implying that COVID-19 is a bad pandemic, or that widespread fatalities are expected,” Doron says.
For the most up-to-date information on the new coronavirus disease, check with the CDC, WHO, and your local department of health, Romero advises.