A 35-year-old man who was the last Middle East Respiratory Syndrome (Mers) patient to be cleared of the disease in the outbreak that killed 36 people in the country earlier this year has tested positive again for the virus, the country's Health Ministry said yesterday.

The man, labelled Patient No. 80, was admitted to Seoul National University Hospital (SNUH) on Sunday with a high fever.

He was rediagnosed with Mers yesterday, just nine days after he was discharged as Mers-free.

A total of 61 people who had come into contact with him, including four family members, medical staff and paramedics, have been quarantined, the Health Ministry said.

The Korea Centers for Disease Control and Prevention said it believed that the man may not be highly contagious as he was found to have only a "minuscule" amount of the virus, according to the Yonhap News Agency .

The man had earlier gone to another hospital - Samsung Medical Centre (SMC) - on Sunday with fever symptoms, and was referred to SNUH.

The patient was being treated for lymphoma when he was first diagnosed with Mers on June 7 and warded at SMC.

He was moved to SNUH on July 3, and discharged on Oct 3, after testing negative for the virus on Oct 1.

South Korea was hit by the largest outbreak of Mers outside the Middle East in the middle of this year, with 186 cases and more than 16,000 people quarantined.

The first Mers patient was diagnosed on May 20 at Pyeongtaek St Mary's Hospital, in Gyeonggi province outside Seoul.

No new cases have been reported since July.

But plans by the government to declare the country Mers-free on Oct 29 will now have to be shelved.

The Mers outbreak took a huge toll on the country's economy, with the retail and tourism sectors badly hit as people stayed home and tourists cancelled their vacations.

The government was criticised for its initial slow response and lack of transparency.

President Park Geun Hye scolded health officials for their "insufficient" action and vowed all-out measures to contain the spread of the virus.

This time, the Health Ministry was quick to react, sending out a media statement just hours after the 35-year-old man tested positive again for Mers.

It also named all the hospitals he had visited.

Last month, the government said it would pay a total of 100 billion won (S$121 million) to 133 medical institutions that were affected by the Mers outbreak.

Pyeongtaek St Mary's Hospital, the epicentre of the outbreak, received 1.1 billion won.

Mers was first reported in Saudi Arabia in 2012.

There is no vaccine or treatment available, and the fatality rate is about 36 per cent globally.