What is a pandemic?
- Simply put, a pandemic is a measure of the spread of a disease.
- When a new disease spreads over a vast geographical area covering several countries and continents, and most people do not have immunity against it, the outbreak is termed a pandemic.
- It implies a higher level of concern than an epidemic, which the US Centers for Disease and Control Prevention (CDC) define as the spread of a disease in a localised area or country.
- There is no fixed number of cases or deaths that determine when an outbreak becomes a pandemic.
- The Ebola virus, which killed thousands in West Africa, is an epidemic as it is yet to mark its presence on other continents.
- Other outbreaks caused by coronaviruses such as MERS (2012) and SARS (2002), which spread to 27 and 26 countries respectively, were not labelled pandemics because they were eventually contained.
Which outbreaks have been declared pandemics in the past?
- A major example is the Spanish flu outbreak of 1918, which killed between 20-50 million.
- Cholera pandemics have been declared multiple times between 1817 and 1975.
- In 1968, a pandemic was declared for H3N2 that caused about a million deaths.
- The last pandemic declared by the WHO was in 2009, for H1N1.
Does the declaration change the approach to the disease?
- Describing the situation as pandemic does not change WHO’s assessment of the risk posed by the virus. However, the categorization as a pandemic can lead to more government attention.
- The categorization by WHO indicates the risk of disease for countries to take preventive measures.
- It will help improve funding by international organisations to combat coronavirus.
Difference Between Endemic, Epidemic, Outbreak and Pandemic:
- AN EPIDEMIC is a disease that affects a large number of people within a community, population, or region.
- A PANDEMIC is an epidemic that’s spread over multiple countries or continents.
- ENDEMIC is something that belongs to a particular people or country.
- AN OUTBREAK is a greater-than-anticipated increase in the number of endemic cases. It can also be a single case in a new area. If it’s not quickly controlled, an outbreak can become an epidemic.
Epidemic vs. Pandemic
- A simple way to know the difference between an epidemic and a pandemic is to remember the “P” in the pandemic, which means a pandemic has a passport. A pandemic is an epidemic that travels.
Epidemic vs. Endemic
- An epidemic is actively spreading; new cases of the disease substantially exceed what is expected.
- More broadly, it’s used to describe any problem that’s out of control, such as “the opioid epidemic.”
- An epidemic is often localized to a region, but the number of those infected in that region is significantly higher than normal.
- For example, when COVID-19 was limited to Wuhan, China, it was an epidemic. The geographical spread turned it into a pandemic.
- Endemics, on the other hand, are a constant presence in a specific location.
- Malaria is endemic to parts of Africa. Ice is endemic to Antarctica.
Endemic vs. Outbreak
- Going one step farther, an endemic can lead to an outbreak, and an outbreak can happen anywhere.
- Last summer’s dengue fever outbreak in Hawaii is as an example. Dengue fever is endemic to certain regions of Africa, Central and South America, and the Caribbean. Mosquitoes in these areas carry dengue fever and transmit it from person to person.
- But in 2019 there was an outbreak of dengue fever in Hawaii, where the disease is not endemic. It’s believed an infected person visited the Big Island and was bitten by mosquitoes there.
- The insects then transferred the disease to other individuals they bit, which created an outbreak.
You can see why it’s so easy to confuse these terms. They’re all related to one another and there’s a natural ebb and flow between them as treatments become available and measures for control are put in place — or as flare-ups occur and disease begins to spread.