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What are outbreaks, epidemics and pandemics?

What are outbreaks
SPEAKER 1: Hello, I’m Dr David Muscatello. And I’m going to talk to you about what are outbreaks, epidemics, and pandemics.
Suppose you come down with measles. Measles is an infectious disease that we don’t see very often anymore. That’s because of immunisation. Measles is a highly infectious disease that spreads very easily between people.
You might get a fever. It might be followed a few days later by a rash. A week later, your friend gets a fever and a rash. Then another friend of yours and some other friends of your friend who you don’t even know get the disease.
It looks like you’re part of an infectious disease outbreak. Outbreaks of infectious diseases that can make people seriously unwell are of great concern to health authorities around the world. Health officials try to prevent and control outbreaks of infectious diseases.
Outbreaks can occur in families, the community, institutions like hospitals, schools, childcare centres, and age care facilities. You may only need as few as three cases of the disease to have an outbreak. But if the disease always occurs sporadically in the community then it may not be an outbreak because some occurrence of the disease is expected. If the disease is usually unknown in the area or has not occurred for a long time then even a single case could mean an outbreak. If the outbreak spreads to the wider community or an entire country, it can be called an epidemic. The terms outbreak and epidemic are often used interchangeably.
An epidemic is formally defined as an increase in the incidence of an infectious disease above the level usually expected for the time and the place.
A pandemic is an epidemic that extends over large areas of the globe. Examples of recent outbreaks and epidemics include the ebola epidemic that affected several countries in Africa. An epidemic of Zika virus is currently spreading across the central region of the Americas. It’s being transmitted by both mosquitoes and humans. The most recent pandemic declared by the World Health Organisation was due to the pandemic influenza A H1N1 virus which is thought to have originated from pigs. That means it was a zoonotic disease. A zoonotic disease is a disease that spreads from animals to humans.
In this presentation you will be learning about what an outbreak or epidemic of infectious disease is and some examples of these. You will also learn about how epidemics become pandemics and about diseases that transmit from animals to human.
After watching this video, discuss the answer to the following questions in the comments section below:
  • Have you heard about any infectious disease outbreaks occurring in your country at the moment?
  • How do you think it started?
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