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  • The coronavirus pandemic makes a big impact

  • Around the world schools and offices are being closed, events are cancelled and hospitals are getting worried of being overloaded

  • This may seem like a movie, but it is all very real

  • This is the evolution of Coronaviruses

  • Coronaviruses are a group of related viruses that cause diseases in mammals and birds including pigs, camels, chickens, cows, cats, horses and humans

  • Most coronaviruses seem to originate from bats

  • But why bats?

  • Bats can fly, live in packed colonies and have a strong immune system

  • Their immune system could drive viruses to replicate faster

  • So, when the virus jumps to mammals or humans with a weaker immune system it can easily cause severe illness or even death

  • Sometimes coronaviruses can jump to other animal species or humans

  • The new coronavirus, SARS-CoV-2, that causes the disease called COVID-19, is thought to have originated from bats that may have infected pangolins before infecting humans

  • Previously, in 2012, another coronavirus causing MERS has jumped from bats to dromedaries before infecting humans

  • And similarly in 2002 the SARS coronavirus used civet cats as an intermediate host before infecting humans

  • A lot is still uncertain about these viruses and their origin

  • Viruses are so small that even with normal microscopes we can't see them

  • This makes them a kind of invisible threat

  • And their ability to mutate rapidly is also why it is very difficult to make a vaccine

  • It may take more than a year before there is a vaccine for COVID-19

  • A corona pandemic that most people haven't heard about is PED, Porcine Epidemic Diarrhea

  • The PED virus didn't infect humans, but killed approximately 7 million of pigs in the United States within one year

  • This is notable since pigs already live in a kind of lock-down, housed in different pens and with limited travel and strict hygiene to prevent transmission between farms

  • Still, the PED virus spread across the US

  • This was because the virus was extremely contagious and could survive up to 28 days on equipment and surfaces

  • By contrast, we may consider ourselves lucky, in a way, that the COVID-19 virus can probably only survive outside humans for up to three days

  • It is also surprising that the mortality rate of PED decreases with age

  • While the mortality rate for COVID-19 increases with age

  • In total there are 7 strains of human coronaviruses

  • Generally they produce mild symptoms of the common cold

  • However, three viruses can cause severe diseases

  • These are SARS, MERS and COVID-19

  • SARS and COVID-19 originated in China, and MERS was first discovered in Saudi Arabia

  • All of these diseases are similar in many ways

  • The transmission is mostly from person-to-person by a droplet spread when someone coughs or sneezes

  • Most infected people first get a high fever

  • Other symptoms for COVID-19 are dry cough, tiredness as well as some less common symptoms

  • Some people for all of these diseases develop a more serious illness featuring pneumonia

  • Pneumonia is an infection in the lungs

  • The air sacs may fill with fluid or pus, causing cough, fever, chills and difficulty breathing

  • The SARS outbreak mostly affected Asia and resulted in 8,000 cases in 2002 and 2003

  • MERS mostly affected the Middle East and resulted in 2,500 cases in 2012 until now

  • MERS is still active although currently there isn't an outbreak

  • The pandemic of COVID-19 already affected most of the world with more than 540,000 cases as of march the 27th

  • The mortality rates are very different

  • SARS has a mortality rate of 10%, MERS as high as 34% and COVID-19 between 3 and 4%

  • This resulted in 774 deaths for SARS, 866 death for MERS and more than 24,000 deaths for COVID-19 so far

  • COVID-19 is easily the scariest of the three and we've no idea where it will end

  • One thing we do know is that everyone must contribute to control how much the virus will spread

  • Step 1, Hygiene: wash your hands frequently with soap, cough in your elbow and avoid touching your face

  • Step 2, Social distancing: keep distance, stay home as much as possible and avoid crowded places especially if you've any symptoms

  • This way we make sure our healthcare systems have enough capacity to help all the sick people and less people will die

  • The only way we can overcome this pandemic is by working together globally

The coronavirus pandemic makes a big impact

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B1 中級 美國腔

冠状病毒的进化(Evolution of Coronaviruses (Animation))

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    joey joey 發佈於 2021 年 05 月 28 日
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