The new coronavirus has killed more than 3,000 people. Over 95,000 cases have been confirmed as of Wednesday. More than 90% of those are in China, though the outbreak has spread to 81 other countries.

The virus emerged at the end of December in the city of Wuhan, which is home to 11 million people. The US reported its first death from the virus on Saturday — a man in his 50s in Washington state. Nine other deaths were reported in Washington state, and one death was reported in California.

More than 150 cases have been confirmed in the US, including 46 people who were quarantined on the Diamond Princess cruise ship in Japan then flown back to the US. Another three confirmed cases are evacuees from Wuhan who were quarantined upon arrival in the US.

The US has also reported several likely cases of "community spread" — patients who had no known exposure to the virus and no travel history in China. These include two cases in California, four in Washington state, and one in Washington County, Oregon.

On February 25, officials at the Centers for Disease Control and Prevention (CDC) said Americans should "prepare for the expectation that this might be bad."

The CDC is asking any citizens returning from five countries — China, South Korea, Italy, Japan, or Iran — who develop a fever, cough, or shortness of breath to seek medical help and self-isolate. US citizens have been advised to avoid all nonessential travel to China, South Korea, Italy, and Iran. Foreign nationals who've been in China within the prior 14 days are currently not allowed to enter the US.

This map shows the current travel warnings:

The virus causes a disease called COVID-19. Most patients develop a fever, cough, and shortness of breath. A recent study from the Chinese Center for Disease Control found that around 80% of coronavirus cases in China have been mild.

Most deaths so far have been reported in the Hubei province, where Wuhan is located. Authorities put the province on lockdown to prevent the spread of the virus; all transportation in and out of Wuhan has been halted.

Airports around the world are screening passengers for the virus and many countries have evacuated citizens and employees from China.

Read more:

The US has confirmed 60 coronavirus cases. Here's what we know about all the US patients.

How the 'failed' quarantine of the Diamond Princess cruise ship started with 10 coronavirus cases and ended with more than 690

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