Coronavirus
Coronavirus

WEHRE DID COVID-19 COME FROM

“When the house is burning down is not the time to start looking for where the matches were”

Stephen Morse

Professor of Epidemiology

Columbia University’s Mailman School of Public Health.

With the advent of coronavirus pandemic in 2020, the world came to a standstill with lockdowns, restrictions and jamming of the day to day activities. The chaos and fear caused by Covid-19 had people burrowing in their nests, awaiting a vaccine or miracle to save them from the brutal and lethal attacks of the virus. Wherein medics and scientists worked conjointly, day and night, to come up with a cure to the disease, researchers probed deeper to unravel the origin of the virus and many theories have been presented in this regard. With World Health Organization (WHO) taking a lead to lay out policies, define emergencies and devise plans to minimize the loss of precious lives caused by this monster, it also brought together a team of intrigued scientists to investigate the roots of where this virus stemmed from.

In this regard, both the WHO taskforce as well as researchers, virologists, microbiologists, epidemiologists and scientists took upon themselves to investigate and find the first cases of the virus, be that in human or in animals. Essentially, this query was and is of great significance because once the origin is exposed, it will be much easier for the scientists to dig out the sources, environmental factors and associated phenomena that became a cause of this spread globally like a fire. As per majority of these studies, the first reported cases emerged in China, in the city of Wuhan, prior this epidemic grew into a pandemic. However, the researchers believe that the virus had started incubating in December, 2019. Furthermore, it cannot be said with conviction that its origin lies in China because detection of the presence of a substance someplace does not equate to its origination from the same place. Many researches in this context point out that the cases of infection prior December, 2019 may have gone unnoticed and started making its mark with noteworthy infected humans rushing for hospitals for medical aid. In order to support this claim, the virologists also studied the blood samples and waste water from that period and discovered traces of the coronavirus in those. However, owing to the lack of substantial evidence, the researchers relied upon the genetic analysis of coronavirus, in order to determine its family tree. This in-depth research was the need of the hour so that the dynamics of virus transmission, its evolution and associated clusters may be established.

The one common fact unanimously agreed upon by most of the researchers is the animal origination of this virus. However, how the same was transmitted to humans is still a matter of scientific debate. Many studies have attributed bats as the main reservoir of coronavirus whereas some associate an intermediary animal like pangolins to be the probable carrier to humans. WHO investigators hinted upon a protein ACE2 that could act as a virus receptor for both animals and humans, through which COVID19 clasps onto cells. However, many conspiracy theory analysts and forecasters also ascribed the origination of coronavirus to a deliberate leakage from a biosafety laboratory in Wuhan, resulting in an international outbreak. However, China has vehemently denied the accusations time and again, even regarding its accidental escape. With the lapse of more than a year since the pandemic first emerged, it can be safely said that it is not man-made and that the components of its genome were already present in bats and generally, in the nature around us. However, despite being key to preventing further spread of coronavirus related diseases, the origination of coronavirus is a mystery that will take years of scientific probe to resolve. By understanding the mechanism of its spread, however, epidemiologists will be better able to suggest the necessary measures so as to avoid an onslaught of its new variants.

As per many scientific studies, the previously known diseases caused by coronaviruses like MERS (Middle East respiratory syndrome) and SARS (Severe Acute Respiratory Syndrome) also occurred due to its animal transmission to humans. Virologists point out that bats in specific are host to various varieties of coronavirus and had historically also played a major role in causing MERS and SARS infections in humans. For COVID-19 as well, bats are the primary suspects of coronavirus transmission with pangolins serving as a possible but not proven link. Such diseases are generally referred to as zoonotic diseases wherein the outbreak is associated to an animal-human transmission and health authorities make it a point to separate the public from such animals that may probably pose a health risk or infection hazard. In order to unearth its emergence and source of origin, the genome of the virus causing pneumonia like symptoms was researched upon in January 2020 by WHO team. The studies identified that the SARS variant of coronavirus outbreak had also emerged in China in 2013 which was followed by MERS, both being associated with the ‘wet market’ of China where various species of animals were stored prior sale to the food industry. Thorough investigations of COVID-19 genetics point out that its genome is 96% similar to the virus that causes infections in a community of bats that exchange this chromosomal material with each other. Research also suggested that these coronaviruses have been circulating unobserved with bats for years and alterations in that spike protein are evidenced to change gene codes, thereby causing infections.

Where the virus came from is a pressing question on everyone’s mind and people have been looking for answer to the same online. But there are numerous myths going around the Internet. One widespread rumor is that the coronavirus has originated from people consuming bat soup in China. But this assumption is false and the exact birthplace of this virus is still unidentified. However, in recent times bats have been the cause of diseases which can spread to humans through increased interaction with bats, consumption of bats and additional exotic animals and augmented trade of caged bats in markets. These circumstances have changed bats’ interactions with humans and have been causing viruses. Resultantly, many people believe that the new coronavirus came from bat meat because when COVID-19 was first identified, a video of a woman eating bat soup went viral thereby sparking rumors that bat soup consumption in China caused the outbreak. However, the clip was filmed in 2016, long before the first COVID-19 cases were diagnosed.

In actuality, coronaviruses are a large family of viruses that affect many different mammals, including bats, cats, camels, cattle etc. Some kinds of coronaviruses also affect humans but most of those viruses cause upper-respiratory illnesses. Although it is rare for animal coronaviruses to spread to people but this had unfortunately occurred with the new coronavirus that caused COVID-19. It has been confirmed that the outbreak stemmed from a wholesale meat market in Wuhan. The virus was found in the area where live animals were stocked. But this does not mean that the virus originated inthe market. It only means the market played a role in dissemination of the virus. One of the research studies also found that out 14 of the first 41 people confirmed to have COVID-19 didn’t visit the wet market, hence suggesting the presence of other sources.

According to a study, it is possible that bats with the new coronavirus were introduced to the market. This might have allowed recombination, or viruses exchanging genetic material to create a new virus. Therefore, bats may have played a role in the COVID-19 outbreak. But it likely wasn’t through the consumption of bat soup. However till date, the exact source of the new coronavirus hasn’t been confirmed and scientists are developing a plan to track the source.

Besides bats and pangolins, another animal associated with COVID-19 origination and transmission is the snake but the evidence in this regard is vague and flawed. It is not yet known whether the new coronavirus spread directly from bats to humans, or via another animal. More recently strong genetic similarities have been found between SARS and COVID-19 and several viruses infecting pangolins. Although the bat viruses are more similar to human SARS and COVID-19 than the pangolin viruses, there are several reasons why the pangolin link is receiving special attention. One is that the sequences of the spike protein genes in SARS and COVID-19 and in pangolin viruses are particularly close. Another is that pangolins are widely sold in live animal markets in China where they are more likely than bats to come into contact with humans.

The coronavirus that conquered the world came from a thumb-sized bat tucked inside a remote Chinese cave. Of this much, scientists are convinced.  Exactly how and when it fled the bat to begin its devastating flight across the globe remain open questions. The Wuhan fish market, seen asa likely breeding ground for the virus, has been scrubbedand shuttered. But the effort is worth it, infectious disease experts said. Understanding the journey of SARS and COVID-19 may provide insights into how the relationship between humans and animals led to the pandemic, as well as other disease outbreaks, including Ebola, Zika and many strains of flu. These are emerging diseases that breach the barrier between animals and humans and cause devastation in human populations. It is an absolute requirement to understand that interface and what is driving that dynamic and what specific issues resulted in diseases breaching that barrier.

The chain of events that led to the worst pandemic in a century started with a tiny, insect-eating mammal with a mundane name, the intermediate horseshoe bat. The species is part of a family of bats that act as natural reservoirs for coronaviruses, notorious for how easily they mutate and can be transmitted from species to species. The bats aren’t bothered by the viruses. The animals they pass them onto aren’t always so lucky. Humans are one of those animals. This happens all the time; a virus harmlessly infects one creature, then finds its way to another, mutates and becomes something new. The newly mutated virus can be insignificant but annoying (like common colds, some of which are caused by coronaviruses) or devastating and deadly (like smallpox).

There’s really not a clear tree where we have forensic evidence to point to exactly where it came from. It looks like it’s a bat-derived virus, and there’s a big question mark after that. Scientists simply don’t do enough surveillance of bats and coronavirus to tell. There’s really not a clear tree where we have forensic evidence to point to exactly where it came from. It looks like it’s a bat-derived virus, and there’s a big question mark after that. Some researchers say the virus most likely came directly from bats, possibly infecting miners who work in bat-infested caves or people exposed to bat feces. Others say it more likely spent some time infecting another animal species before leaping to humans. 

Despite a persistent conspiracy theory that SARS and COVID-19 was developed in a lab, perhaps an infectious disease lab in Wuhan, there’s no evidence to support the claim and plenty to counter it. In March 2019, a group of researchers found the virus most closely resembled bat viruses and was not man-made. Their analyses clearly showed that SARS and COVID-19 are not a laboratory construct or a purposefully manipulated virus.

However, wild animal markets and consumption of wildlife continue to pose dangers and global surveillance and drugs that can treat a wide spectrum of viruses will help to address all coronaviruses. In summary, current data indicate that COVID-19 originated directly or indirectly from a bat coronavirus, but these findings remain suggestive rather than conclusive because genetic and other investigations are still at a preliminary stage. There is substantial diversity among SARS-like coronaviruses circulating in bats and other animals and the identification of precisely where the virus originated will need further sampling and surveillance of animals. After the emergence of SARS and MERS (and other zoonotic diseases) there were calls for restrictions on wildlife consumption by humans and the sale of wild animals in live markets. These recommendations are being restated during the current COVID-19 pandemic; whether they are justified on these grounds depends on knowing the animal origin of SARS-CoV-2 and how it entered the human population.

About Zahid Shaukat

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