The Centers for Disease Control and Prevention (CDC) today confirmed that the 2019 Novel Coronavirus (2019-nCoV) has spread between two people in the United States, representing the first instance of person-to-person spread with this new virus here.
Previously, all confirmed U.S. cases had been associated with travel to Wuhan, China, where an outbreak of respiratory illness caused by this novel coronavirus has been ongoing since December 2019. However, this latest 2019-nCoV patient has no history of travel to Wuhan, but shared a household with the patient diagnosed with 2019-nCoV infection on January 21, 2020.
Recognizing early on that the 2019-nCoV could potentially spread between people, CDC has been working closely with state and local partners to identify close contacts of confirmed 2019-nCoV cases. Public health officials identified this Illinois resident through contact tracing. Both patients are in stable condition.
“Given what we’ve seen in China and other countries with the novel coronavirus, CDC experts have expected some person-to-person spread in the U.S.,” said CDC director Robert R. Redfield, M.D. “We understand that this may be concerning, but based on what we know now, we still believe the immediate risk to the American public is low.”
Limited person-to-person spread with 2019-nCoV has been seen among close contacts of infected travelers in other countries where imported cases from China have been detected. The full picture of how easily and sustainably the 2019-nCoV spreads is still unclear. Person-to-person spread can happen on a continuum, with some viruses being highly contagious (like measles) and other viruses being less so.
MERS and SARS, the other two coronaviruses that have emerged to cause serious illness in people, have been known to cause some person-to-person spread. With both those viruses, person-to-person spread most often occurred between close contacts, such as healthcare workers and those caring for or living with an infected person. CDC has been proactively preparing for the introduction of 2019-nCoV in the U.S. for weeks, including:
• First alerting clinicians on January 8 to be on the look-out for patients with respiratory symptoms and a history of travel to Wuhan, China.
• Developing guidance for preventing 2019 novel coronavirus (2019-nCoV) from spreading to others in homes and communities.
• Developing guidance for clinicians for testing and management of 2019-nCoV, as well as guidance for infection control of patients hospitalized or being evaluated by a health care provider.
CDC is working closely with Illinois health officials and other local partners. A CDC team has been on the ground since the first 2019-nCoV-positive case was identified and is supporting an ongoing investigation to determine whether further spread with this virus has occurred.
It is likely there will be more cases of 2019-nCoV reported in the U.S. in the coming days and weeks, including more person-to-person spread. CDC will continue to update the public as we learn more about this coronavirus. The best way to prevent infection is to avoid being exposed to this virus. Right now, 2019-nCoV has not been found to be spreading widely in the United States, so CDC deems the immediate risk from this virus to the general public to be low. However, risk is dependent on exposure, and people who are in contact with people with 2019-nCoV are likely to be at greater risk of infection and should take the precautions outlined in CDC’s guidance for preventing spread in homes and communities.
For the general public, no additional precautions are recommended at this time beyond the simple daily precautions that everyone should always take. It is currently flu and respiratory disease season, and CDC recommends getting vaccinated, taking everyday preventive actions to stop the spread of germs, and taking flu antivirals if prescribed. Right now, CDC recommends travelers avoid all nonessential travel to China.