A total of 175 people were exposed to Thailand's only case of Mers and the patient's condition has improved, according to the Public Health Ministry.
In an updated statement on Saturday afternoon, the ministry said it had been in touch with all 175 and had instructed them to stay away from public spaces and for medical personnel to monitor their health.
Also on Saturday, South Korea's health ministry said that no new cases of Middle East Respiratory Syndrome (Mers) had been recorded, for the first time in 16 days, and there were no more deaths.
The deadly disease, which was first identified in Saudi Arabia, has killed 24 people and infected 166 people in Korea since it was detected there last month.
On Friday, Public Health Minister Rajata Rajatanavin told reporters that the chances of a Mers outbreak in Thailand like the one in South Korea were low.
"Health authorities were able to isolate the patient very quickly before he could travel any further and infect others. The patient spent most of his time in hospitals," he said.
The virus was first detected in Thailand in a 75-year-old man from Oman who had travelled to Bangkok for treatment of a heart condition.
On Thursday, the man was moved from Bumrungrad Hospital to an infectious diseases facility in Nonthaburi.
Three relatives of the man are also being kept in isolation rooms at the institute and had tested negative for the virus, said Surachet Satiniramai, acting permanent secretary at the ministry.
"The condition of the Mers patient is better overall," he said. "The chest x-rays show improvement and he can eat soft food."
Authorities have said it had taken nearly four days to confirm the illness.
Doctors at Bumrungrad said on Friday that it had quarantined 58 staff members but that there was no sign of panic and no patients at the hospital had asked for transfers.
Mers was first identified in humans in Saudi Arabia in 2012 and the majority of cases have been in the Middle East. Isolated cases have cropped up in Asia before the South Korean outbreak.