Health authorities are trying to reach more than 200 people who may have come into contact with Thailand's second Middle East Respiratory Syndrome patient, who remained in stable condition on Monday.
Dr Amnuay Gajeena, director-general of the Department of Disease Control, said 239 people had crossed paths with the Omani patient. Thirty-two have been located and placed under watch or quarantine for 14 days.
The group includes passengers aboard the same flight the 71-year-old Omani arrived in Thailand, as well as staff at his hotel and hospital. Forty of the people were considered at high risk of infection, Dr Amnuay said.
The patient's son, as well as a Thai woman seated next to him on the plane, and the taxi driver who picked him up at Suvarnabhumi airport were quarantined in an isolation ward, he said.
All the persons in possible contact with the patients have been identified but 207 have yet to be reached. All would be watched for two weeks, the incubation period for Mers, the minister said.
The Omani and his son arrived in Thailand on Friday. He was admitted at Bumrungrad Hospital in Bangkok early Saturday.
A week prior to his arrival, he had received treatment at a hospital in Oman but his condition had not improved and he flew to the country with a fever and cough.
He was transferred to the Public Health Ministry's Bamrasnaradura Infectious Diseases Institute in Nonthaburi province Saturday evening after his Mers infection was confirmed at Bumrungrad.
Dr Amnuay said that the patient's condition remained stable on Monday but he still had a mild fever and cough. However, he could eat and walk.
Public Health Minister Piyasakol Sakolsatayadorn said on Monday that the patient needed considerable oxygen supplies.
The first Mers case in Thailand also was an Omani man, aged 75. He was confirmed with the disease in mid-June. He was cured at the Bamrasnaradura Infectious Diseases Institute and released in early July.
As of Monday, the World Health Organization reported 1,626 Mers patients in 26 countries of whom 586 had died.