Global health officials have warned the coronavirus outbreak that has killed more than 1,100 people and sickened about 45,500 could get worse before it gets better. As of Tuesday, there were only two clusters of the virus outside of China; a significant one on a cruise ship docked in Japan and a handful of cases in southern England. At least 174 people from the cruise have been diagnosed with the disease, and hundreds more were being tested.

But while those foreign disease clusters grew this week, China said the number of new cases confirmed inside the country had declined for two days in a row. As of Wednesday, China had 1,114 deaths from the disease, now officially named COVID-19. The only other fatality has been in the Philippines.

While the declining infection rate in China could indicate that draconian control measures implemented by the country are helping, the chief scientist for the World Health Organization has warned it’s still possible that many cases are lurking around the world undetected, so more localized outbreaks could emerge. If that happens, what is still considered a Chinese epidemic could grow into a global pandemic.

The U.S. still had only 13 confirmed cases as of Wednesday, and the CDC said none of them had suffered severe symptoms.

The WHO gathered top disease specialists Tuesday for a second day of brainstorming in Geneva, to try and answer questions about the new disease. The agency’s boss opened the meetings with a plea for global unity against “a common enemy that does not respect borders or ideologies.”