Fourteen new cases of Middle East Respiratory Syndrome -- one of them a pregnant woman -- were confirmed Thursday, bringing the total number of cases to 122.
One of the 122 confirmed cases, a South Korean male, is being monitored by Chinese authorities since he arrived in the Chinese city of Guangdong in late May.
The South Korean outbreak is the biggest outside of Saudi Arabia, where the little-understood virus was first detected in 2012.
So far, 10 people in South Korea have died after contracting MERS and more than 3,800 people have been placed under quarantine. More than 950 people have been released from quarantine after they tested negative for MERS.
The situation led South Korea's central bank to unexpectedly cut interest rates Thursday, out of concern that an outbreak of MERS will dampen growth and spending.
The Bank of Korea trimmed its key interest rate a quarter percentage point to 1.5% due to "concerns following the MERS outbreak about contractions in domestic demand activities such as consumption and in economic sentiment," a statement read.
A day earlier, South Korean President Park Geun-hye's office announced that she had canceled her trip scheduled for Sunday to the United States in order to address the situation.