Updated Feb. 21, 11:46 a.m. ET
Last month, a British man went to a conference in Singapore, then on a ski trip to the French Alps.
What he didn't know when he arrived in the Alps was that he was infected with the virus behind the COVID-19 outbreak.
During his stay at a ski village, it appears he infected 11 other people, who subsequently traveled on to the U.K. and Spain, the World Health Organization says.