Hugo Guevara, Public Health Microbiologist Supervisor, shows a tray used to hold flu samples at the California Public Health Laboratory in Richmond, Calif.
Hugo Guevara, Public Health Microbiologist Supervisor, shows a tray used to hold flu samples at the California Public Health Laboratory in Richmond, Calif. on Tuesday, Jan. 28, 2014. (Kristopher Skinner/Bay Area News Group) ( Kristopher Skinner )