The U.S. CDC has issued a new warning.
The organization warned of the possibility of a community-based spread of the coronavirus.
The potential infection occurred after a person who did not have relevant travel history was exposed to a known patient.
The infection was detected in California, bringing the total number of COVID-19 cases in the United States to 15.
According to Reuters, community spread is the spread of an illness for which the source of infection is unknown.