Comprehensive coverage

Corona has been declared a worldwide epidemic - what is the difference between a disease outbreak, an epidemic and a global disease?

Simply put, the difference is in the dimensions. The worldwide corona epidemic is enormous on a historical scale

Image: The corona virus was first diagnosed in Wuhan province, China, at the end of 2019 and spread rapidly around the world. This map is updated as of March 5, 2020. Source: CDC
Image: The corona virus was first diagnosed in Wuhan province, China, at the end of 2019 and spread rapidly around the world. This map is updated as of March 5, 2020. Source: CDC

(Update to the news by Avi Blizovsky, 11/3/2020)

Now it's official. The World Health Organization today (Wednesday) declared the corona as a worldwide epidemic (pandemic). The chairman of the organization, Tedros Adhanom Ghebreyesus, said at a press conference in Geneva, Switzerland, that the extent of the spread of the virus has reached a level where it can be defined as such. He further added that despite repeated warnings and ringing of all possible bells, not all countries have taken the necessary measures to contain the outbreak of the epidemic and therefore it has become a global epidemic. It was also reported today that the Biological Institute in Ness Ziona is working on developing a vaccine for Corona, but its trial will last several months.

What is the difference between an outbreak, an epidemic and a global epidemic?

Rebecca Fisher, professor of epidemiology at the University of Texas addressed the various definitions in an article she published yesterday (9/3).

I would like to dispel the ambiguity prevailing in the public in understanding the terms "disease outbreak", "epidemic" and "global epidemic" (pandemic). The difference is in the dimensions.

A disease outbreak is small, but unusual. Through long-term geographic surveillance after disease outbreaks, epidemiologists learn to anticipate how many cases will occur in a certain period in a certain place and among a certain population. An outbreak is an abnormality in morbidity above the expected, usually small.
Expect a higher than normal number of children who get diarrhea in the dorms. When one or two get sick in one week it's normal, but if 15 get sick at once - it's an outbreak.

When a new disease appears, outbreaks are easier to spot because the expected morbidity was zero. An example of this is the number of cases of pneumonia that unexpectedly spiked among people who visited the seafood and animal market in Wuhan, China. Today it is understood that they were caused by an outbreak of a new type of corona virus, known today as SARS-CoV-2.

When health authorities notice an outbreak, an investigation is launched to determine who is affected and how many patients there are. Authorities are using this information to map out ways to contain the outbreak and prevent further illnesses.
An epidemic is greater than an outbreak in terms of the number of patients and the size of the area where there is morbidity.

An epidemic is basically an outbreak in a larger geographical area. When people outside of Wuhan tested positive for the coronavirus, epidemiologists realized that the outbreak was spreading. This indicates that the containment efforts were not enough or started too late. This is not surprising, since there is still no treatment for the disease or a vaccine against it. The spread of the disease throughout China meant that the outbreak was an epidemic.

A global epidemic is international and uncontrolled.

When an epidemic spreads to many countries or to many regions of the world, it is considered a global epidemic. However, there are epidemiologists who define an epidemic as such only when there is local infection within the new areas.
For example, a sick traveler returning to the US from China does not create a global epidemic, but when it infects family and friends, it is something else. If there are local outbreaks, epidemiologists will agree that efforts to control global spread have failed and it is already a global epidemic.

The terms have a political meaning and not just a medical one

Epidemiologists deal first and foremost with disease prevention. This does not necessarily align with the broad interests of governments and international medical organizations.
When these words are written, the World Health Organization assesses the risk of global spread of the corona virus as "very high". This is the highest level of risk in the rating, one below the declaration of a global pandemic. In other words, the World Health Organization is still optimistic and hopes that if far-reaching measures are taken, it will be possible to contain the local outbreaks.
But the author of this article, along with other scientists and public health authorities, already see the current situation as a global epidemic. The official numbers are over a hundred thousand cases in close to a hundred countries. Also, community spread has been documented in the US and everywhere. According to the classic definition, it is a global epidemic.
Previous declarations of the corona virus or any other infectious disease as a global epidemic instruct governments, agencies and aid organizations around the world to divert efforts from containment to relief. This has economic, political and social consequences on a global scale.
An official announcement should not incite fear or lead to the hoarding of masks. It does not mean that the virus has become more violent or deadly. Nor did your risk of infection increase.
With that said, this is a historic event.

For an article in The Conversation

More of the topic in Hayadan:
The new corona virus: the last epidemic to hit the human race
No country in the world is prepared to deal with the corona virus, and most of them are unable to receive data in real time
The spread of the corona virus is a breeding ground for conspiracy theories. Why is it dangerous?

Shushi Bloch also participated in the preparation of the news, who helped translate Prof. Fisher's article.

We are appealing to additional volunteers to help us update the surfers of the science website and science enthusiasts in Israel with the latest details related to the corona epidemic, from reliable sources, and which can be used according to copyright laws. Please contact or through the scholar's Facebook page.

3 תגובות

  1. What is most amazing is that there is no reference to the severity of the disease, but only to its spread.
    There is a difference between a disease that causes 4% death among those infected with it, compared to a disease from which only 0.1% of those infected die.
    And if, for example, no one dies from the disease, but it spreads very quickly - should we take serious measures just because of the rate of spread of the virus?

  2. The most significant step you didn't mention was that they took away human freedom and every day it gets worse

  3. Sorry, I didn't understand the criteria for distinguishing between an epidemic and a disease and a global disease.
    If you have already gone to explain the matter then go to the end and give numbers.
    How many people will get sick for it to be defined as an epidemic/disease/global disease?
    How many foci should there be to define a global epidemic/disease? How many patients is this considered a focal point?
    What are the criteria for a very high spread risk? What are the criteria for high risk? For medium/low risk?
    Is the intensity of the disease taken into account in the above definitions? Let's say a disease that ends in sneezing can also be considered a global epidemic/disease? And if not, then what is the meaning of these criteria in themselves when trying to build a policy based on these definitions?

    These are not just questions, because based on these definitions the State of Israel was arrested and hundreds of thousands of people lost their headquarters.

    If you look at the numbers locally as well as globally, it seems that the corona virus is much less common and dangerous than the flu, and still measures have been taken that have catastrophic significance for the Israeli economy and the world.
    The question is whether these definitions are accurate and reflect the problem.
    The follow-up question is to what extent the problem that arises corresponds to the steps taken (this is beyond the scope of this article, but food for thought).

Leave a Reply

Email will not be published. Required fields are marked *

This site uses Akismat to prevent spam messages. Click here to learn how your response data is processed.