BEIJING, May 29  -- A man from the Republic of Korea (ROK) has tested positive for the deadly Middle East Respiratory Syndrome (MERS) in south China's Guangdong Province, health authorities confirmed on Friday.

The man, 44, flew from the ROK to Hong Kong on Tuesday and entered Huizhou City via Shenzhen, according to the National Health and Family Planning Commission.

He had close contact with MERS patients at home and expressed discomfort as early as May 21.

Huizhou health authorities put the man under observation in isolation early on Thursday morning and also isolated people who had close contact with him. Of 38 known contacts, no unusual findings have been reported so far, the commission said.

The man reported a high temperature of 39.5 degrees Celsius and a chest X-ray showed lesions on his lungs, indicating possible infectious pneumonia, it said.

The patient is the son of the third confirmed MERS case in the ROK and the brother of the ROK's fourth confirmed case.

He Jianfeng, an official with the Guangdong Provincial Center for Disease Control and Prevention, said it could not rule out the possibility of other people having caught the disease from the patient, as he had taken long-distance buses, stayed in hotels and attended conferences before he was put under observation.

He also suggested those returning from the Middle East go to doctors if they showed symptoms such as fever.

MERS is a respiratory illness caused by a new type of corona virus. The first case was identified in Saudi Arabia in 2012. There is no vaccine or treatment for the disease, which has a fatality rate of 40.7 percent.