• Ann Falco

COVID-19: Its History and Origin


In 2019, the novel coronavirus swept across the world causing a global pandemic. The pandemic continues as many countries are faced with new surges of infections and variant strains of the virus. Amidst the research, news, and published literature, many people still ask the question “where did this virus actually come from?


History of COVID-19

The current COVID-19 pandemic is caused by a virus called Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The coronavirus is named for the crown-like spikes that are present on the surface of the virus. This virus originates from a large family of viruses that are common in humans and several other species of animals, including cattle, camels, cats, and bats. The World Health Organization (WHO) named the disease that caused the pandemic as coronavirus disease 2019, abbreviated as COVID-19. In this new name, the ‘CO’ stands for ‘corona’, ‘VI’ for ‘virus’, and ‘D’ for disease. Prior to this, the disease was referred to by scientists as 2019 novel coronavirus or 2019-nCoV.


The CDC states that there are many types of coronaviruses that affect humans, some of which cause common mild upper-respiratory tract illnesses. COVID-19, however, is caused by a novel (new) coronavirus that has not previously been seen in humans. As mentioned by the CDC, COVID-19 is caused by a new coronavirus that was first identified in Wuhan, China, in December 2019. The virus was discovered in patients with severe respiratory disease. Scientists do not know the exact source of the current outbreak of COVID-19; however, it is suggested that it originally came from an animal, likely a bat. The genetic sequences (DNA) identified from patients in the United States are similar to the genetic sequences that China initially reported, suggesting a likely single, recent emergence of this virus from an animal reservoir.



Origin of COVID-19

Coronaviruses are zoonotic pathogens (an organism that can produce disease) originating in animals and transferred to humans through direct contact. A virus that is regularly transmitted from an animal to a human is called a zoonotic virus. All coronaviruses that caused epidemics (including COVID-19) are believed to have originated in bats. Research determined that bats are the main hosts (carriers) of many coronaviruses. However, in several cases, the viruses were transmitted to humans through an intermediate animal host. Many researchers suspect that COVID-19 emerged from the seafood markets in Wuhan, China. Several of the earlier reported cases of COVID-19 were linked to the seafood markets in that specific area. Evolutionary analysis of the COVID-19 virus revealed that it is most similar to the bat SARS-like coronaviruses, and for the similarity, it was named SARS-CoV-2.

The World Health Organization (WHO) reports that all SARS-CoV-2 isolated from humans to date are closely related genetically to coronaviruses that have been isolated from bat populations, specifically, bats from the genus Rhinolophus. This close genetic relation suggests that the ecological origin is from the bat populations. Bats in the Rhinolophus genus are commonly found across Asia, Africa, the Middle East, and Europe. SARS-CoV-2 is not genetically related to other known coronaviruses found in farmed or domestic animals. Genetic sequencing data suggests that the start of the outbreak resulted from a single point introduction in the human population around the same time that the coronavirus was initially reported in humans in Wuhan, China.


Investigations that were conducted to further understand the epidemiology of COVID-19 and the original source of the outbreak discovered a direct link to a seafood market in Wuhan City, where seafood, wild, and farmed animal species were sold. Several of the initial patients were either stall owners, market employees, or regular visitors to this market. Additionally, environmental samples obtained from the market tested positive for SARS-CoV-2, further corroborating that the market was the source of the outbreak or played a major role in the initial development of the outbreak.


Now that scientists have a better understanding of the genetic sequencing of the virus and its origin, this information could provide more insight into the viral transmission and reveal potential therapeutic agents. Antiviral drugs are used to interfere with the viral replication machinery in the target cells. Given that viruses have similar actions of infection, many studies suggest the use of successful antiviral drugs for the treatment of COVID-19. Additionally, the use of antimalarial drugs Chloroquine and Hydroxychloroquine have been reported to show promising results against SARS-CoV-2. Hydroxychloroquine has been associated with a safer clinical profile making it the prioritized drug to treat malaria, viruses, and autoimmune conditions. Currently, the use of hydroxychloroquine is part of many approved COVID-19 treatment protocols, especially in combination with other antibiotics and antiviral drugs. These medical advances and discoveries provide a bright outlook for virus treatment and together they will help scientists better control viral outbreaks in the future.

 

Speaking Plainly:

  • This virus originates from a large family of viruses that are common in humans and several other species of animals, including cattle, camels, cats, and bats.

  • There are many types of coronaviruses that affect humans, some of which cause common mild upper-respiratory tract illnesses.

  • Genetic sequencing data suggests that the start of the outbreak resulted from a single point introduction in the human population around the same time that the coronavirus was initially reported in humans in Wuhan, China.

  • Samples obtained from a seafood market in Wuhan, China tested positive for coronavirus, further corroborating that the market was the source of the outbreak.

  • Many studies suggest the use of successful antiviral drugs for the treatment of COVID-19. Additionally, the use of antimalarial drugs Chloroquine and Hydroxychloroquine have been reported to show promising results against SARS-CoV-2. These medical advances and discoveries provide a bright outlook for virus treatment and together they will help scientists better control viral outbreaks in the future.