More than 680 people in South Korea are isolated after having contact with patients infected with a virus that has killed hundreds of people in the Middle East, health officials said Monday.

South Korea has reported 17 cases of Middle East Respiratory Syndrome (MERS) since diagnosing the country's first case last month in a man who had traveled to Saudi Arabia.

South Korea's cases have connections to the first patient, either medical staff who treated him or patients who stayed near the man at the hospital before he was diagnosed and isolated.

Also, the son of one of the patients ignored doctor's orders to cancel a trip to China, where he was diagnosed as that country's first MERS case last week. China isolated the South Korean man at a hospital, and Hong Kong authorities said Sunday that 18 travelers were being quarantined because they sat near him, but they were not showing symptoms.

South Korean Health Ministry official Kwon Jun-wook told reporters Monday that 682 people who had close contact with the patients, such as their family members and their medical staff, were isolated at their homes or state-run facilities to prevent the spread of the disease.

Ministry officials said the number could rise.

MERS was discovered in 2012 and has mostly been centered in Saudi Arabia. It belongs to the family of coronaviruses that includes the common cold and SARS, and can cause fever, breathing problems, pneumonia and kidney failure. The virus has spread primarily through contact with camels, but it can also spread from human fluids and droplets.

There have been 1,167 cases of the virus worldwide and 479 of the patients have died, according to the European Center for Disease Prevention and Control.