Coronavirus reaches the US: Everything we know about the deadly virus

A virus that has infected over 400 people and caused nine deaths has reached the US. Here's everything we know about the mysterious new disease.

A never-before-seen virus, detected in the central Chinese city of Wuhan, has claimed nine lives and infected hundreds of Chinese citizens with a pneumonia-like illness, according to China's National Health Commission. It was first reported to the World Health Organization on Dec. 31, 2019 and has been under investigation since.

WHO indicates there are still many unknowns, but Chinese scientists have linked the disease to a family of viruses known as "coronaviruses," the same family as the deadly SARS and MERS viruses.

Scientists are yet to fully understand how destructive the new virus, dubbed 2019-nCoV, might be. Researchers and investigators are just beginning to understand where it originated, how it is transmitted, how far it has spread and what symptoms patients present with.

As of Jan. 21, case numbers have skyrocketed to over 440 in China and abroad. Chinese authorities also confirmed health workers have been infected with virus, suggesting it has achieved human-to-human transmission.

As a result, authorities are taking steps to guard against its spread and the WHO will convene an Emergency Committee to explore whether the virus constitutes a public health emergency on Wednesday, Jan. 22.