There are many instances in history wherein contagious diseases were spread by viruses that travel from animals to humans – but we don’t seem to have learnt anything.
For wet markets, live animals are usually slaughtered next to each other. Last year, the World Health Organization (WHO) were told on New Year’s Eve of a cluster of cases of unknown causes of pneumonia in Wuhan City, China Province of Hubei.
The Wuhan novel coronavirus (WN-CoV) was described in January of this year as a new respiratory disease that was previously unseen in humans. In trying to contain this epidemic, more than 20 million residents have been locked down in Wuhan and other towns, with public transport closed.
What is the situation internationally?
Many people affected are in China, but cases from other countries have been reported: Thailand, the USA, Australia, Singapore, Taiwan, Malaysia, South Korea, Japan, France, Vietnam, Nepal, Canada, Cambodia, Sri Lanka, Germany, and Bavaria.
As of January 27, the total number of cases confirmed by China increased to 4,515, up from 2,835 a day before. One hundred six people have died at the time of writing, but if the infection spreads before symptoms appear, the death tolls are likely to rise considerably.
UPDATE: January 29, the epidemic killed 132 people and infected nearly 6,000 people in China.
What are coronaviruses?
Coronaviruses are a common type of virus that cause mild illnesses, such as common cold, but may cause more severe problems, such as severe acute respiratory syndrome.
Where did they come from?
The new virus is thought to have originated in a crowded so-called ‘wet market’ in Wuhan, selling marmots, birds, dogs, pigs, badgers, rabbits, bats, snakes, wolf pups, cicadas, scorpions, bamboo rats, squirrels, foxes, salamanders, turtles, crocodiles and civet cats. Live wild and farmed animals are packed next to each other in crowded cages – think of it as an all-you-can-eat infectious disease smorgasbord.
We’ve seen it with HIV / AIDS, Ebola, Zika, avian influenza (bird flu), and SARS before, all of which originated in animals. Ebola emerged from the monkeys, contaminated with bats, and then consumed in the African forests by farmers.
The 2003 SARS epidemic, which killed 774 people, was believed to be caused by an animal virus, again perhaps from bats, which spread to civet cats and infected humans in southern China’s Guangdong province.
Despite this, wild animal markets were only temporarily banned, and now there are out and trading again.