The death toll from a coronavirus outbreak which started in Wuhan has soared to 106 while nearly 1,300 new cases have been confirmed, the Chinese authorities reported today (28 Jan). The total number of confirmed cases now stood at close to 4,200 in China.
Experts haven’t yet confirmed the animal species that enabled it to spread to people, but they have some guesses. According to a report from Business Insider, scientists in China compared the genetic code of the Wuhan coronavirus to other coronaviruses and found it to be most similar to two bat coronavirus samples.
“There’s an indication that it’s a bat virus,” Vincent Munster, a scientist at Rocky Mountain Laboratories, told Business Insider. “We know a fair amount of viruses on the World Health Organization’s Blueprint list of priority diseases have either a direct or indirect link with bats,” he added.
Some researchers also thought that a population of bats could have infected snakes, which passed the virus to humans as they were being sold at the Huanan Wholesale Seafood Market in Wuhan.
Coronaviruses are said to be zoonotic diseases, meaning they spread from animals to people. Because wet markets put people and animals in close contact, it can be easy for a virus to make an inter-species jump.
“Poorly regulated live-animal markets mixed with illegal wildlife trade offer a unique opportunity for viruses to spill over from wildlife hosts into the human population,” the Wildlife Conservation Society said in a statement last week.
Bats harbor significantly higher proportion of zoonotic viruses than all other mammals
It has been observed that coronavirus in saliva and feces from bats can infect other animals, and indirectly transmit to humans. “Bats and birds are considered reservoir species for viruses with pandemic potential,” Bart Haagmans, a virologist at the Erasmus Medical Center in Rotterdam, Netherlands, told Business Insider. “Because these viruses have not been circulating in humans before, specific immunity to these viruses is absent in humans,” he added.
In the 70s, at least three other pandemics, not counting SARS, have been traced back to bats. The creatures were the original source of Ebola, which has killed 13,500 people in multiple outbreaks since 1976; Middle Eastern respiratory syndrome, better known as MERS, which can be found in 28 countries; and the Nipah virus, which has a 78% fatality rate.
In 2017, the National Institutes of Health (NIH), an agency under the U.S. Department of Health, conducted a comprehensive analysis of mammalian host-virus relationships. It demonstrated that bats harbor a significantly higher proportion of zoonotic viruses than all other mammals. Bats can also fly, making them ideal carriers across large geographical areas, easily reaching human population. For example, the bat population in a Yunnan cave where NIH researchers were taking samples from, lived just over one kilometer from the nearest village.
In another study by NIH in March last year, it predicted there would be more outbreaks of large-scale disease in China linked to coronaviruses. It said, “During the past two decades, three zoonotic coronaviruses have been identified as the cause of large-scale disease outbreaks – Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and Swine Acute Diarrhea Syndrome (SADS).”
“They have common characteristics, such as they are all highly pathogenic to humans or livestock, their agents originated from bats, and two of them originated in China,” it added. “Thus, it is highly likely that future SARS- or MERS-like coronavirus outbreaks will originate from bats, and there is an increased probability that this will occur in China.”
Nine months after the publication of the NIH report, Wuhan virus emerged and started to ravage China, resulting in locking down of multiple Chinese cities.
The World Health Organization has so far not declared the outbreaks of the disease caused by Wuhan virus a global public-health emergency, since China has quarantined Wuhan and other cities to stop the virus’ spread. But on last Sunday, WHO has corrected its assessment of the outbreak to be at a very high risk in China, high in regional level and high at the global level, it had previously labelled the outbreak as moderate risk.