How is COVID-19 Different from SARS and MERS?

During the early stages of its spread in the United States you likely heard the majority of people referring to the current pandemic as Coronavirus. Now everyone is calling it COVID-19. Why? No, it’s not to improve sales of Corona beer, which people still aren’t buying. Its because Coronavirus is a broader term that also encompasses other older versions of a related virus. Coronaviruses are a family of viruses that infect animals, and in some cases, these viruses spread to humans. The primary examples of these that you may have heard of are MERS-CoV and SARS-CoV. The current 2019 Coronavirus is referred to as SARS-CoV-2, commonly, COVID-19. All of these Coronaviruses have their origin in bats.

MERS-CoV was first reported in 2012 in Saudi Arabia, though later investigation determined it likely actually started in Jordan. Either way, the MERS-CoV cases originated in the Middle Eastern Region, earning it its name, Middle East Respiratory Syndrome. MERS-CoV has similar symptoms to COVID-19, fever, cough and shortness of breath. All of the cases reported for this Coronavirus were associated with travel from the Middle East, including an outbreak of the virus in Korea in 2015 In 2014, two cases of MERS-CoV were reported in the United States from healthcare workers who had been to Saudi Arabia. They fully recovered and did not spread the virus to anyone else.

Severe acute respiratory syndrome (SARS) was first reported in 2003 in Asia and spread to countries in North America, South America, and Europe. According to the World Health Organization (WHO), a total of 8,098 people worldwide became sick with SARS during the 2003 outbreak. Of these, 774 died. There were only 8 cases in the United States. There were no more cases after 2004, and like MERS, the US cases were all people who had traveled abroad.

774 people died from SARS. The deathtoll for COVID-19 meanwhile has now reached over 50,000 according to a recent article from the Washington Post. So, what is the difference between the current Coronavirus and the ones from the past two decades? First, the two viruses are not the same. They are related, but they are not the same virus, so the illnesses they cause are different things. SARS was actually more deadly, meaning a higher percentage of people who got it died, but it was much less infectious than COVID-19, and COVID-19 has surpassed the number of people who died from SARS because it has now infected many more people.

Healthline reports, a major difference between SARS and COVID-19 is that SARS symptoms were severe, making it pretty obvious who had it, making contact tracking and containment of infected people easier. Another important difference is the ability of these different viruses to spread. It took SARS six months for cases to exceed 5,000 in mainland China. COVID-19 did that in just one month. The CDC pages for both SARS and MERS report that there was no ongoing spreading beyond those who had direct contact with it by traveling abroad. This has not been the case with COVID-19. The CDC reports ongoing community spread. Community spread means “people have been infected and it is not known how or where they became exposed”. Due to the highly contagious nature of COVID-19 measures such as social distancing are extremely important to help slow the spread of the virus.

To learn more about the new Coronavirus, COVID-19, check out NSH’s COVID-19 resources page. The page contains links for laboratory professionals related to disinfection, laboratory precautions, as well as important updates from health agencies.












The National Society for Histotechnology is a professional member organization for individuals actively involved in the histology profession. NSH has over 3,000 members worldwide, and is the leading provider of histology focused continuing education.  



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