The number of people diagnosed with Middle East Respiratory Syndrome (MERS) in South Korea continued to remain unchanged at 186 on Friday, with the death toll also staying flat for nearly three weeks.

The country's death toll from the disease remained at 36 for the 20th consecutive day, the Ministry of Health and Welfare said.

Out of the 186 people diagnosed so far, 138 have been discharged from hospitals following complete recoveries.

The remaining 12 are still hospitalized, but 11 of them have already tested negative for MERS, according to ministry officials.

Most of them are only recovering from complications caused by MERS.

In addition to those diagnosed, 45 other people were in isolation as suspected cases. The number surged from nine on the previous day.

Since the country reported its first case on May 20, nearly 16,700 people have been subject to isolation for possible infection after coming in close contact with MERS patients.

The number of people in isolation dipped to zero earlier in the week.

The 45 people currently in isolation include two people who showed possible symptoms of MERS following their recent trips to Middle Eastern countries. The rest are those who later came in close contact with them.

MERS is a viral respiratory syndrome that was first reported in Saudi Arabia in 2012.

The disease has since affected over 1,300 people throughout the world, but most of the cases have been linked to Saudi Arabia and other Middle Eastern countries.

South Korea has the second-largest number of MERS cases in the world after Saudi Arabia, which has reported over 1,000 cases since 2012.

Still, the fatality rate of the disease in South Korea remains at 19.4 percent, while the rate for the rest of the world is around 40 percent.