Coronavirus: What is 'community spread’ and what do we do about it?

A person in northern California being treated for the novel coronavirus (COVID-19) could be the first case of “community spread” in the United States.

Health officials say they are investigating the person, who is a resident of California's Solano County, located between Sacramento and San Francisco. The person had no known exposure to the virus through travel or close contact with a person who is known to have the virus, California Department of Public Health officials said.

“Community spread” means the virus is circulating among the local community and infecting people without an obvious source of the infection – such as a person who is already ill with the virus – according to the Centers for Disease Control and Prevention.

The CDC is continuing to look for the source of the patient’s infection. It's "possible" that the individual "may have been exposed to a returned traveler who was infected,” the CDC said in the statement.

The other known cases of CODI-19 in the U.S. can be tracked to someone who traveled outside of the U.S. or who has been in contact with someone who did.

The California patient has not traveled outside of the U.S. and had not appeared to have had contact with someone who did.

“It’s the first signal that we could be having silent transmission in the community,” Lawrence Gostin, director of the World Health Organization Collaborating Center on National and Global Health Law, told The Los Angeles Times. “It probably means there are many more cases out there, and it probably means this individual has infected others, and now it’s a race to try to find out who that person has infected.”

Community spread could be caused by contact with surfaces that have the virus on them. Health officials suggest that people remember to wash hands as a defense against the virus, stay away from people who are coughing or sneezing and stay home if you are feeling ill.