Feliciano Morelos, 19, a farmworker from Oaxaca state in Mexico, was being held in a jail cell equipped with special air filters so other inmates do not breathe the same air, according to the District Attorney's office.
Tuberculosis, which is deadly if not diagnosed early and treated, is caused by bacteria and transmitted through droplets spread by coughing and sneezing.
Morelos is believed to be the first person jailed in Santa Barbara County for disobeying an isolation order from a public health officer and endangering public safety, officials said.
"He was really posing a very serious public health risk," said Paige Batson, the county's disease control and prevention manager.
Authorities say Morelos refused on two occasions to remain quarantined. He told the Santa Barbara News-Press for Sunday's editions that he left quarantine at his uncle's urging and did not realize he was not supposed to leave.
"I didn't understand the laws here. I won't escape again," he said. He told the paper he hoped to be moved to a hospital.
Health officials believe he infected 56 people, mostly family members in California and Washington. Nine people have developed an active case of the disease.
A total of 14,871 cases of active TB were reported in the United States last year, according to the Centers for Disease Control and Prevention. About 2 million people around the world die annually of TB.