As a word, coronavirus was limited to researchers and doctors. The trail of deaths that Covid-19 continues to leave behind across the globe has made coronavirus a fearful word. More than 46 lakh people have died of complications caused by the coronavirus infection. This particular coronavirus is named SARS-CoV-2.
Now, a study has found that coronavirus spillover from bats, the natural reservoir of the virus, is common to the tune of 4 lakh infections every year. The new report paints a grim picture of the situation on the ground indicating that lakhs of people may be infected with coronaviruse, the same family to which SARS-CoV-2 belongs and the one which causes Covid-19.
The study was conducted by EcoHealth Alliance and Singapore’s Duke-NUS Medical School. It found that on an average close to 4 lakh such infections occur each year.
However, most of these cases go unnoticed, the researchers said. The reason: these infections trigger mild or no symptoms at all in the infected persons.
Another factor is that these infections aren’t easily transmitted from one person to another as happened in the case of Covid-19.
The study, however, raises a serious concern about spillover events that could lead to human-to-human transmission of the virus and possibly resulting in yet another deadly coronavirus pandemic.
“This is probably the first attempt to estimate how often people are infected with SARS-related coronaviruses from bats,” Edward Holmes, an evolutionary biologist at the University of Sydney who wasn’t involved in the research told Bloomberg.
The study published in a preprint in medRxiv has found that some bat SARS-related coronaviruses (SARSr-CoVs) could infect people directly and that their spillover is more frequent than previously recognised. Researchers estimate that “an average of 4,00,000 people per year are likely infected with bat-origin coronaviruses related to SARS-CoV and SARS-CoV-2 in southern China and Southeast Asia alone.”
Bats are very common mammals and play a vital role in most ecological systems around the world, EcoHealth Alliance, which conducted the study, said. They come into frequent contact, not just with humans, but with other wild and domestic animals presenting ample opportunity for viral spillover.
“The best way to prevent outbreaks and pandemics is to prevent that initial spillover and to equip medical systems and clinicians in high-risk hotspot areas to recognise cases and control outbreaks before they get out of hand,” it said.
The organisation said that 14 million (1.4 crore) people worked in the wildlife trade in China as recently as 2016 and that each of these people came into regular contact with animals and this was likely to increase the overall risk of spillover and spread.
Researchers hope that the analyses would allow the scientific community to design better intervention measures, increase surveillance, contact tracing in case another spillover event happens.
Meanwhile, several countries are investigating the origins of the coronavirus, which was first reported in China about two years ago. US President Joe Biden recently said that China was withholding “critical information” on the origins of Covid-19 after the US intelligence community said it did not believe the virus was a bio-weapon but remained split on whether it escaped from a lab.
The US intelligence has ruled out that the coronavirus was developed as a weapon, and most agencies assess with “low confidence” it was not genetically engineered.
The intelligence and the scientific communities remain divided on the pathogen’s origins, with four agencies and the National Intelligence Council judging in favour of natural exposure to an animal as the likely explanation, and one agency favouring the lab leak theory.