The 14-day quarantine of the 68 people who were in contact with the Mers victim from Oman ended Wednesday night, a health official said.
Dr Opart Karnkawinpong, deputy director-general of the Department of Disease Control, said on Wednesday that 16 people with high risk of infection and 52 others with low risk of infection had passed the standard 14-day quarantine period. Those in the high risk category would undergo physical checkups and final laboratory tests to ensure they are completely free of the Middle East Respiratory Syndrome before their discharge on Thursday.
"There are two risk situations for Thailand from Mers. One involves contact with a patient with symptoms and the other comes from people arriving from areas with the epidemic. The first risk has been contained and will vanish tomorrow," Dr Opart said.
There were also changes in the risk posed by visitors arriving from countries with Mers outbreaks. Dr Opart said the situation was improving in South Korea because the number of patients was not growing.
However, the number of Mers patients in Saudi Arabia was increasing and Thai travellers to the Middle Eastern country were being advised on self-protection, Dr Opart said.
He said the Omani Mers patient, the only case to be reported in Thailand, was continuing to improve at Bamrasnaradura Infectious Diseases Institute in Nonthaburi province on Wednesday.
The 75-year-old man was no longer coughing, but he was being retained in isolation because he still needed treatment for his chronic illness. The condition of his three relatives was normal, Dr Opart said.
The Omani man arrived on June 15 for treatment of a heart condition at Bumrungrad Hospital in Bangkok. His Mers infection was confirmed on June 18.
Dr Opart said that as of June 26, there were 1,356 Mers patients in 26 countries and 484 of them had died. In South Korea, as of June 27, there were 182 patients and 33 of them had died.
From Jan 1 to June 30 this year, 134 people showing signs of viral infection arrived in Thailand from countries with the Mers outbreak -- 70 from South Korea and 64 from the Middle East. Samples from the people were tested and they were cleared.