Dr Suwannachai Wattanayingcharoen, director-general of the Department of Disease Control, said on Friday (February 7) there were now 615 people in Thailand suspected of carrying the 2019-nCoV coronavirus.

The number of confirmed cases remained unchanged at 25, with 16 being treated in hospital and the other nine recovered and released.

Suwannachai attributed the rise in suspected cases to updated criteria generating more details and redefining the term “suspected”.

The Thais flown home this week from China’s central Hubei province, where the virus outbreak began, fall into two categories, he said – four people suspected of being infected but awaiting lab tests to verify earlier indications they were safe, and the rest, by far the most, who appear healthy but will remain under observation for more than another week.

Two of the returnees have begun showing signs of infection and now occupy isolation rooms at hospitals in Chonburi and Sattahip, he said.

Mental Health Department chief Dr Kiattiphum Wongrajit said the 138 returnees were all feeling stress and three were showing symptoms of depression. The mental condition of all returnees is being continuously monitored, he said.

Suwannachai said an infected Chinese tourist being treated at Rajavithi Hospital in Bangkok has improved, while a 70-year-old Thai bus driver remains on a ventilator because he also has tuberculosis.