The coronavirus spreading in China and the SARS outbreak of 2003 have two things in common: Both are from the coronavirus family, and both started in wet markets.
At such markets, outdoor stalls are squeezed together to form narrow lanes, where locals and visitors shop for cuts of meat and ripe produce. A stall selling hundreds of caged chickens may abut a butcher counter, where uncooked meat is chopped as nearby dogs watch hungrily. Vendors hock skinned hares, while seafood stalls display glistening fish and shrimp.
Wet markets put people and live and dead animals — dogs, chickens, pigs, snakes, civets, and more — in constant close contact. That makes it easy for a virus to jump from animal to human.
On Wednesday, authorities in Wuhan, China — where the current outbreak started — banned the trade of live animals at wet markets. The specific market where the outbreak is believed to have begun, the Huanan Seafood Market, was shuttered on January 1. The coronavirus that emerged there has so far killed 25 people and infected more than 830.
“Poorly regulated, live animal markets mixed with illegal wildlife trade offer a unique opportunity for viruses to spillover from wildlife hosts into the human population,” the Wildlife Conservation Society said in a statement.
Coronaviruses are zoonotic diseases, meaning they spread to people from animals. In the case of SARS, and likely this Wuhan coronavirus outbreak as well, bats were the original hosts. The bats then infected other animals, which transmitted the virus to humans.
Here’s what Chinese wet markets look like.