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Pandemics&Epidemics - Coggle Diagram
Pandemics&Epidemics
Epidemic
What causes an epidemic?
Introduction of a new disease- Many epidemics begin when a new disease in introduced to a population. This occurred when the Europeans brought smallpox to the Americans killing as much as 90% of the native population.
Lower resistance to a disease- Sometimes famine and poor nutrition can cause a population to have lower resistance to a disease causing an epidemic. Natural disasters and wars.
Increased virulence of the disease- Sometimes the pathogen (germ) that causes a disease may change and become more virulent. This means that the pathogen mutates to become more harmful or severe, and can more easily infect people and make them sick.
Natural disasters and wars can trigger the start of epidemics by causing infected water, bringing in new diseases, and lowering the resistance to disease of the population by making environmental changes or limited medical supplies/assistance.
Infected food and water- One way an epidemic can begin is if the food or water gets infected with disease. If the local water supply of a city gets infected, then a number of people of the city will become sick, starting an epidemic.
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How do they end?
Fewer hosts- When an epidemic first starts out it can attack the weakest and most susceptible people. These people may die or survive. If these people survive they may build up immunities to the disease. Over time, the disease finds fewer and fewer hosts it can easily attack. Eventually the epidemic slows down and comes to an end.
Seasonal- Some diseases are seasonal. The flu, for example, is spread more easily during the winter and tends to dies out come spring time.
Even though epidemics can spread quickly and kill millions of people, they eventually do come to an end. There are different reason why an epidemic may end:
Fewer carriers- Sometimes the carriers of the disease may become inactive. An example of this is malaria that is transmitted by mosquitoes. Mosquitoes becomes inactive during the cold weather or winter.
Pandemic
What is a pandemic?
A pandemic is an epidemic that has spread across a large region, typically across multiple continents or worldwide. Examples of pandemic diseases include typhus, influenza, the Bubonic Plague (Black Death), malaria, smallpox, and Coronavirus.
Six Stages of a Pandemic The World Health Organization (WHO) describes six stages of a pandemic virus:
There are small clusters of the disease found, but it is not spreading rapidly.
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The virus has spread to at least two countries, and a full-fledged pandemic is imminent.
The virus is found in animals, but not in humans.
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