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A WHO team tries to solve the mystery of where SARS-CoV-2 came from and how it jumped on humans.
Where he came from? How did it spread? Could it be related to the consumption of bushmeat? When exactly did the contagious virus jump to humans? Is there a possibility that someone did it in a laboratory from which it escaped?
Covid-19 or SARS-CoV-2 has killed more than 1.6 million people, left millions more out of work, and confined families to their homes. However, the world is unsure of the origins of the pathogen.
Researchers agree that the virus is zoonotic, meaning that humans contracted it from an animal.
A team of experts from the World Health Organization (WHO) will travel to China next month. His field research covers Wuhan, the city where the first cases of a pneumonia-like illness were first reported a year ago.
Linking the chain of events that brought the virus from the animal kingdom to cities is crucial to preventing future outbreaks. But the process is not easy, especially when it comes to wild animals.
“Tracking a disease in the wild can be challenging. An animal carcass must be fresh enough to isolate the pathogen, ”says Dr. Prayag HS, a veterinarian from the Indian state of Karnataka, who researches big cats in their natural habitat.
“In most cases what happens is that when we go to the place, the animal is almost in a state of decomposition. The terrain and the fact that sometimes large areas have to be covered, it is difficult to recover the body ”.
Wuhan, China, could have reported the first cases of Covid-19, but that does not mean the virus originated there. (AP)
Not enough clues
A coronavirus, which matches 96.2 percent sequence homology to SARS-CoV-2, has been identified in bats in China’s Yunnan province.
The way a zoonotic disease is normally transmitted is that it jumps from a reservoir animal to an intermediate species, which then transmits it to humans. Bats are known to be reservoirs for different viruses, including the Hendra virus, which killed horses and people in Australia in 1994.
But a specific reservoir for SARS-CoV-2 has not yet been identified and the route of transmission remains a mystery even though scientists have found traces of the new coronavirus in cats, ferrets, hamsters, mink and other animal species.
A live virus, and not just antibodies, needs to be extracted from a bat to show that it is indeed the reservoir.
Two-thirds of all infectious diseases in humans come from animals and three-fourths of all come from wildlife. The source of some of the deadliest zoonotic diseases continues to elude researchers.
Epidemiologists spent four decades collecting and analyzing samples from mammals, birds and reptiles, but have not been able to find the source of the deadly Ebola virus.
The animal reservoir behind the outbreak of severe acute respiratory syndrome (SARS), like Ebola, is still unknown, according to the WHO.
Scientists on the 10-member WHO team heading to China have previously worked on identifying sources of other viruses. Dr Marion Koopmans, a virologist from the Netherlands, helped establish that dromedaries were an intermediate host for the virus that causes MERS, another type of coronavirus.
The WHO says that Wuhan could have reported the first cases, but that does not necessarily mean that the virus could not have appeared first elsewhere.
Some countries identified Covid-19 cases weeks before the first was officially reported, and unpublished reports of positive sewage samples could suggest that the virus may have circulated undetected for some time, it says.
The Ebola virus has killed thousands in Africa. However, its origin remains unknown. (AP file)
Denials
Outgoing United States President Donald Trump has repeatedly blamed China for the spread of Covid-19 by delaying the release of information after the virus outbreak. Beijing denies delaying the issue.
China is also wary of the WHO’s focus on Wuhan. Earlier this month, the state-owned Global Times published stories saying the virus could have originated elsewhere.
Geopolitics and the fact that multiple vaccines have hit the market have overshadowed the debate about the origin of Covid-19.
Experts say it is important to discover how the virus reached humans to prepare for future outbreaks.
Infectious zoonotic diseases like Covid-19, which spread from person to person, such as a forest fire, are very rare.
For example, rabies, caused by an animal bite, is very lethal but not transmitted. Ebola, HIV, SARS, MERS, and now Covid-19 are just a few examples where viruses have spread due to human interaction. HIV started out as a zoonosis, but later morphed into a human-only strain.
What is alarming is that these infectious outbreaks have emerged one after another over the past 40 to 50 years; pathogens that have lived in the animal kingdom for thousands of years are only now spreading to humans.
“Why is that? This is a million dollar question,” Prayag says.
“But I do believe that if you follow the law of nature, nothing goes wrong. I think at some point we became greedy. Humans have cut down trees and destroyed the ecosystem. Now nature tells us: ‘Look, you are not the boss, I am the boss.’
Source: TRT World
