The Korea Centers for Disease Control and Prevention (KCDC) has confirmed four more patients as of Thursday morning, bringing the total to 23 cases.

The 20th confirmed case is a 41-year-old Korean woman who is a family member of the 15th patient. The KCDC transported her to Armed Forces Capital Hospital Wednesday after her test result showed positive under self-quarantine. The 15th confirmed patient is known to have either visited or worked at "The Place," the section of Korean stores in the International Fashion Center in Wuhan, China.

The 21st patient is a 59-year-old Korean female who contacted the sixth patient and quarantined herself, responding positively to the test. She was transferred to the Seoul National University Hospital Wednesday. The 22nd patient, confirmed early Thursday, is a 46-year-old Korean man who is a family member of the 16th patient. He also showed a positive result to the test in self-quarantine. He was moved to the Chosun University Hospital in Gwangju.

The 16th and 18th patients were confirmed of infection after returning from their travel to Thailand last month.

The 23rd patient is a 58-year-old Chinese woman who entered Korea on Jan 23. Her test response was positive and escorted to a nationally designated isolation facility on Thursday morning after a public health center confirmed she had a fever.

The KCDC will release epidemiological information after finishing the survey and continue to conduct preventive measures.