South Korea's tally of patients suffering from Middle East Respiratory Syndrome has risen to seven.
Authorities say one person who may have been infected as slipped away from voluntary home quarantine and taken a trip to China.
Yang Byung-kook, director of the Korea Centres for Disease Control and Prevention, breaks down the latest figure at a press conference.
"The tally of infected patients rose to seven, six among them caught the virus from the first confirmed case. There was no additional infection caused by secondary infected patients."
The Health Ministry said the son of the second confirmed victim of the outbreak, who was himself being observed for possible infection, broke voluntary home quarantine and left South Korea for China.
"We confirmed on May 27 that a suspected patient of Middle East Respiratory Syndrome (MERS) left for China on May 26. Under international health regulations, we notified the World Health Organization for the Western Pacific region and China's Health Ministry to take him in to be examined and treated."
Yang added Chinese authorities are investigating the whereabouts of the suspected victim.
First identified in humans in 2012, MERS is caused by a coronavirus from the same family as the one that triggered China's deadly
2013 outbreak of Severe Acute Respiratory Syndrome.
There is no cure or vaccine.
