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Source and Spread of the Virus

Chinese health authorities first posted the full genome of the 2019-nCoV in GenBankexternal icon, the NIH genetic sequence database, and in the Global Initiative on Sharing All Influenza Data (GISAIDexternal icon) portal which has helped with detection of this virus. CDC is posting the full genome of the 2019-nCoV viruses detected in U.S. patients to GenBank as sequencing is completed.

2019-nCoV is a betacoronavirus, like MERS and SARs, both of which originate in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal source.

Early on, many patients in the outbreak of 2019-nCoV in Wuhan, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. Later, a growing number of patients reportedly did not have exposure to animal markets, indicating person-to-person spread. Chinese officials report that sustained person-to-person spread in the community is occurring in China. Person-to-person spread has been reported outside China, including in the United States and other countries.

Situation in U.S.

Imported cases of 2019-nCoV infection in travelers have been detected in the U.S.  Person-to-person spread of 2019-nCoV also has been seen among close contacts of returned travelers from Wuhan, but at this time, this virus is not currently spreading in the community in the United States.

The U.S. government has taken unprecedented steps related to travel in response to the growing public health threat posed by this new coronavirus, including suspending entry in the United States of foreign nationals who recently have visited China. Measures to detect this virus among those who are allowed entry into the United States (U.S. citizens, residents and family) who recently have been in China also are being implemented.

Illness Severity

Both MERS and SARS have been known to cause severe illness in people. The complete clinical picture with regard to 2019-nCoV is not fully understood. Reported illnesses have ranged from mild to severe, including resulting in death. Learn more about the symptoms associated with 2019-nCoV.

There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.