A US citizen evacuated from China amid the coronavirus outbreak was mistakenly released from a San Diego hospital on Monday, after officials were told by the US Centers for Disease Control and Prevention (CDC) the person was in the clear.

The CDC subsequently advised that the patient had in fact tested positive for the virus.

The patient arrived last week on a flight carrying US citizens evacuated from China and was one of four admitted to UC San Diego and held in isolation.

After authorities said on Sunday tests on the four people for coronavirus came back negative, the individual was discharged to quarantine quarters at Marine Corps Air Station Miramar.

In a short statement on Monday, UC San Diego Health said it had been advised by CDC officials that “further testing revealed that one of the four patients tested positive”.

“The confirmed positive patient was returned to UC San Diego Health for observation and isolation until cleared by the CDC for release,” the hospital said.

The patient and another from Miramar were being held in isolation units at UC San Diego facilities and said to be “doing well” with “minimal symptoms”.

The CDC did not immediately comment on the new case, which would be the 13th in the US after a patient was confirmed in Wisconsin last Wednesday.

The previously confirmed cases in Arizona, California, Illinois, Massachusetts, Washington and Wisconsin are all said to be “doing well”.

“The ones who were sicker have improved,” Dr Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, said last week.

It was not immediately clear how long the San Diego patient was circulating inside quarantine after initial tests came back negative, what route the evacuee took out of the hospital, or which of two hospital locations they were held at.

A total of 232 US citizens and family members are serving 14-day government-mandated quarantine after arriving on the Miramar base from China.

China’s national health commission said on Tuesday the death toll had reached 1,016, up 108 from the day before, including 103 in Hubei province and the first time more than 100 deaths had been reported in one day. A total of 42,638 people have been infected in China, the commission said.