A total of 61 people have been isolated after South Korea's last Middle East respiratory syndrome patient, who had been recovering from the disease after being released Oct. 3, was rehospitalized Sunday and tested positive again for the virus, according to the Health Ministry.
The quarantined individuals include the patient's family members, hospital inpatients and their guardians and medical professionals.
However, the chance of them being infected by the virus from the particular patient is "very low," according to medical professionals and the government.
"It seems like a very small amount of the virus particles that had been incubating inside the patient's body has been detected," said Dr. Kim Ik-joong from the Seoul National University Hospital.
Following the Health Ministry's announcement, a local news outlet accused the Samsung Medical Center, where the patient contracted the disease while staying at its emergency facility in May, of not recognising the patient when he visited the hospital again Sunday after experiencing a high fever.
According to the report, he was treated at the hospital's emergency room, instead of a quarantine facility, and may have exposed the virus to other patients in the room.
The 35-year-old patient was moved to Seoul National University Hospital's special quarantine facility Sunday, the same day he visited the SMC, after showing signs of MERS.
He tested positive for the virus while staying at the Seoul National University Hospital on Monday.
The patient was South Korea's 80th confirmed MERS case, and the last to recover and be released from the hospital.
The patient, who has also been suffering from cancer, was first exposed to the virus while staying at the Samsung Medical Center in May.
He was confirmed as a MERS patient on June 7, and received treatment at a quarantine facility until his release on Oct. 3. Before his release, he tested negative for the virus two consecutive times.
In response to the accusations, SMC said while it is true that the patient was treated at its emergency room, he was placed in a special facility "located inside the emergency property."
"The patient has been visiting our hospital mostly for cancer treatment," said Park Jung-eun from the hospital.
"When he arrived (on Sunday), the only symptom he had was fever. We placed him in a special room, where only one patient can stay, inside the emergency facility regardless, and all of the medical professionals wore protective gear."
The hospital was the largest infection source of the MERS outbreak in South Korea, which has claimed 36 lives since May.
A total of 91 Koreans were reported to have contracted the virus at the hospital in Seoul, accounting for 49 per cent of all confirmed cases in the country.
Last month, the hospital vowed to invest 100 billion won (S$121 million) to revamp its emergency facilities and come up with vaccines for the virus as part of its post-MERS plan.
On Monday, just hours before the Health Ministry announced the rehospitalization of the MERS patient, the SMC said it was replacing its president, Dr. Song Jae-hoon, with Dr. Kwon O-jung, as part of measures to better deal with infectious diseases in future.
Korean authorities declared a de facto end to the outbreak of MERS on July 28. The Health Ministry had initially planned to announce the official end of MERS for the country on Oct. 29.