Washington, Feb 29 (IANS): The Santa Clara County Public Health Department in Northern California has confirmed a second coronavirus case of unknown origin, bringing the total number of infections in the US to 60.

On Friday, Santa Clara health officials said a female senior with chronic health conditions was found to be infected with COVID-19 when she was treated for a respiratory illness, reports Xinhua news agency.

The county's Public Health Laboratory received the specimens on Thursday and performed the testing.

The patient had no known travel history nor exposure to any other infected people.

The health department said it has been working to identify the contacts and understand the extent of exposures relating to the new patient.

The woman was the third case of COVID-19 confirmed in Santa Clara, but she was different from the previous two cases where the two patients had a history of travelling to China or exposure to infected individuals.

"This new case indicates that there is evidence of community transmission but the extent is still not clear," said Sara Cody, director of the Santa Clara Public Health Department.

Health officials said the department will conduct community surveillance to determine the extent of local transmission.

On Wednesday, the Centers for Disease Control and Prevention confirmed the first case of person-to-person transmission of coronavirus in the country.