NEW DELHI :
As more countries caution their citizens about travelling to China following a new coronavirus outbreak, there is a growing concern why the world’s most populous country is emerging as a hotbed of new diseases.
The latest outbreak is a respiratory illness caused by a new strain of coronavirus, which has so far infected over 400 people across central China, spreading from the city of Wuhan, where the first case was identified on 31 December 2019, and killing at least 17. As per the latest reports, the virus has travelled to Japan, South Korea, Thailand and the US.
Scientists are yet to find how the virus jumped from animals to humans. However, initial investigations point to the sale of live animals at the seafood market in Wuhan.
“Nobody can say how this new virus must have infected humans. In case of SARS, bats were said to be reservoirs of the virus, which transmitted it to civets and then to humans. But, we got no clear answers till the end," Delhi-based virologist Dr Shobha Broor said.
The SARS outbreak in 2003 was linked to the animal market in China and the H7N9, which spread in China in 2013, was linked to a market of live birds.
“China sees a lot of unsafe animal-human interaction, which is behind the spread of most of these zoonotic viruses, which transmit from animals to humans. And, unlike India, the animal markets (wet markets) have live animals, which are kept in closed space and culled for fresh meat. These places are frequented by a lot of people and are a hotbed of infections; so if one human gets infected, it will only spread," added Dr Broor.
High population density and developed transport links aid rapid spread of viruses.
The new disease has emerged barely six years after the East Asian country reported world’s first-ever case of an avian influenza virus infecting humans. The H7N9 virus, which normally circulates among birds, was never found to have infected humans until China recorded its first case in March 2013. The infections rose to 144, killing 50.
Much earlier, in November 2002, China saw one of the most deadly outbreaks—Severe Acute Respiratory Syndrome (SARS-CoV)—caused by a coronavirus. It travelled to 37 countries, infecting 8,098 people and killing 774 in eight months.
In 2016, too, a new strain of coronavirus was identified in China that killed 25,000 piglets, though it did not infect humans.
As of Wednesday, the source of the new viral outbreak remains under investigation and researchers have not identified the animal species that might have harboured the virus.