Global health officials will decide Thursday whether to declare a public health emergency over the coronavirus as cases multiply in Wuhan, China.

“The continued increase in cases and the evidence of human-to-human transmission outside China are of course both deeply concerning,” Tedros Adhanom Ghebreyesus, World Health Organization director-general, said Wednesday of his decision to hold a meeting. “Although the numbers outside China are still relatively small, they hold the potential for a much larger outbreak.”