Scientists are still trying to determine the origin of the coronavirus, but the predominant theory is that it began in a food market in Wuhan, China.
So-called "wet markets" — usually a jumble of stalls carrying produce, seafood, some farmed meat — are found across China, as well as in many other parts of the world. The problem is that these wet markets sometimes also carry live animals — occasionally including illegal, sometimes exotic, wildlife — bought and slaughtered on the spot, increasing chances for the spread of disease.