SEOUL • A South Korean man has been diagnosed with the potentially deadly Middle East Respiratory Syndrome (Mers) and is being treated at a hospital in Seoul, the Korea Centres for Disease Control and Prevention (KCDC) has said.

The 61-year-old patient had been on a business trip to Kuwait from Aug 16 to Sept 6, and returned to Seoul via the United Arab Emirates last Friday, according to the KCDC.

This is the first time since July 2015 that an outbreak of Mers has been reported in South Korea, Reuters reported.

"As far as we know, 20 people, including flight attendants and medical staff, have been in close contact with the patient and they are under isolation at home," KCDC director Jeong Eun-kyeong told a press briefing yesterday.

The patient visited a local hospital during his stay in Kuwait for diarrhoea, which recurred on his way back home, the Yonhap news agency reported.

He was rushed to the emergency room of Samsung Medical Centre in Seoul after he arrived at Incheon International Airport.

He has then transferred to Seoul National University (SNU) Hospital, where he tested positive for the disease.

Dr Kim Nam-jung,who is treating the patient at the SNU Hospital, said the man is not in a critical condition now but warned that his condition could deteriorate in the next one to two weeks "judging from our experiences from the previous outbreak".

The infectious disease swept South Korea in 2015, leading to 38 fatalities. Mers is thought to be carried by camels and most of the known human-to-human transmission cases have occurred in healthcare settings.