Thai health officials Thursday said a 75-year-old man from the Middle East was confirmed to have MERS, the country\’s first case after a deadly outbreak of the virus hit South Korea.

Thai health officials Thursday said a 75-year-old man from the Middle East was confirmed to have MERS, the country's first case after a deadly outbreak of the virus hit South Korea.

"(The man) is from a Middle Eastern country. The (test) results confirmed that he has Middle East Respiratory Syndrome (MERS)," said Rajata Rajatanavin, Thailand's Public Health Minister, adding the patient had arrived in the kingdom with his family three days ago.

Thailand had investigated around 20 people for the virus, all of who tested negative.

MERS has spread at an alarmingly rapid pace in South Korea since the first case was diagnosed on May 20, infecting 165 in what is the largest outbreak outside Saudi Arabia and prompting a major public health scare.

Earlier on Thursday World Health Organization chief Margaret Chan had expressed guarded optimism over South Korea's ability to contain the MERS outbreak, saying it was now "on a very good footing" after an initially slow response to the virus which has killed 23 people.