A California patient who appears to be America's first case of a coronavirus transmission of unknown origin has prompted two major questions: How was she exposed to the virus, and who else might have it?
California public health officials on Thursday said they are trying to find those answers through contact tracing, a process that entails tracking down anyone in recent weeks who might have had contact with the patient, a woman whose identity they are not revealing.
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Dr. Sonia Angell, director of the state's Department of Public Health, said at a news conference that since Wednesday — when the test came back positive for the coronavirus — local, state and federal health officials have been "contacting any individuals who might have been exposed, and they're isolating them."
This is not the first instance of the coronavirus in the U.S., or even in California, but it is the first time a patient in this country has no clear connection to another sick person.
Experts say that in this case, contact tracing is the right approach to stave off "community spread," which is when a virus starts circulating within a local community and the source of infection is unclear.
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