The pneumonia outbreak was first reported in Wuhan City, central China's Hubei Province, in December. Experts have attributed the outbreak to a novel coronavirus that has since spread across China and abroad.

Here is what we know so far:

- Confirmed cases: Over 9,000 in China, over 90 abroad

- Deaths: 213

- Human-to-human transmission confirmed

- Health experts say the virus has the potential to mutate

- 31 provinces, autonomous regions and municipalities on the Chinese mainland have launched Level I emergency response.