A California coronavirus patient believed to be the first U.S. case from "unknown" exposure was not tested for several days because federal health officials believed he did not meet the criteria, officials say.The patient was transferred to UC Davis Medical Center on Feb. 19, according to a staff memo from Dr. David Lubarsky, the CEO of University of California, Davis, Health."Upon admission, our team asked public health officials if this case could be COVID-19. We [...]