Just five days after announcing that the outbreak of Middle East respiratory syndrome in South Korea was showing signs of losing steam, the nation’s health authorities revoked their stance and warned more cases may be identified in the future.

Seoul reported four more MERS cases Wednesday, while announcing that it placed 298 more people under quarantine to prevent possible infection.

The Health Ministry also reported the nation’s first MERS case that occurred outside of hospitals, which may be a sign that community transmissions of the disease have taken place in the country.

As of Wednesday afternoon, the virus has killed 27 people and infected 179. No deaths were reported on the same day, although 16 patients are currently in unstable condition. Meanwhile, 13 more patients have been discharged from hospitals, raising the total number of recovered individuals to 67.

A total of 3,103 people -- an increase from 2,805 the day before -- were under quarantine Wednesday, while the fatality rate of the disease remained at 15 percent.

Concerns have been rising as it was revealed on Tuesday that the 173rd patient, a 70-year-old caregiver, visited three different medical clinics before being hospitalized at the Hallym University Medical Center in Seoul, where she was eventually diagnosed with MERS.

“We thought the MERS spread was showing signs of slowing until Sunday,” Kwon Deok-cheol from the Health Ministry. “But right now we can’t say we are still thinking the same way as more clinics have been newly infected by the virus.” 

The nation’s first MERS case that occurred outside of hospitals has been also reported. According to health authorities, the 175th patient is believed to have been infected by his late wife, the 118th patient, who died from MERS on June 13, before she was admitted to the hospital.

His late wife was infected by the 14th patient while caring for her husband, who had been hospitalized for pneumonia at the Good Morning Hospital in Pyeongtaek, Gyeonggi Province, from May 23-29. After being discharged, he and his 67-year-old wife were placed under quarantine together at home until June 10, the day the wife was officially diagnosed with MERS. She died three days later.

The 175th patient, 75, had been asymptomatic even after his wife’s death, but started experiencing a fever on June 21. He was officially diagnosed with MERS earlier this week. Considering the maximum incubation period of MERS is 14 days, the Health Ministry said it is most likely that the 175th patient was infected by his late wife at home, not at the hospital in Pyeongtaek.

While fears have been escalating over the possibility of community-transmission of MERS, the World Health Organization assured on Friday that the risk to the general public was low.

“Even if transmission spills over into the general community, such cases are not likely to sustain further transmission,” Dr. Margaret Chan, director general of WHO, told reporters in Seoul last week.

The Health Ministry also announced on Wednesday that the Samsung Medical Center, where 48 percent of all confirmed patients were exposed to the virus, will continue to be partially shut down indefinitely.

The Seoul-based facility, which was initially shut down on June 13, had been scheduled to resume its services on Wednesday.

Since June 13, the hospital has been banned from performing any surgical procedures except for in an emergency, as well as receiving new patients and visitors. Its emergency room has been completely shut down.

“It’s a joint decision made by the government and civil medical experts,” said Kwon from the Health Ministry.

“We’ve decided that it would be safer to keep the hospital closed especially after we learned that the 137th patient, an ambulance worker, continued to work in and out of the hospital while showing MERS symptoms from June 2-10.”

Health authorities have also decided to temporarily shut down Konkuk University Medical Center in Seoul, where the 76th MERS patient stayed from June 16-19 and infected four others so far.

Authorities are urging those who visited the Hallym University Medical Center in Seoul from May 17-22, Mok Cha-su internal medicine clinic (223 Sangil-dong, Gangdong-gu, Seoul) from June 10-11, Bon otolaryngology clinic (391 Godeok-ro, Gangdong-gu, Seoul) on June 15 and Gangdong neurosurgery clinic (45-24 Myeongil-dong Gangdong-gu, Seoul) on June 16 to let their doctors know that they may have been exposed to the virus should they seek medical help for any symptoms or diseases.

They are also asked to report to the authorities immediately should they experience MERS-like symptoms, including a high fever, coughing and shortness of breath, by calling 120 or contacting the nearest public health center.

By Claire Lee (dyc@heraldcorp.com)