In addition, the Republic of Korea Air Force announced that one of its chief master sergeants has been quarantined and tested positive for MERS infection in an initial test at a military medical facility. The officer has to undergo another set of tests to be finally confirmed as a MERS patient by the Health Ministry’s Center of Disease Control.If confirmed, it would be the first MERS case in the Korean military.Following the announcement, about 100 soldiers at the Osan Air Base in Pyeongtaek, Gyeonggi Province, have been quarantined. The sergeant is currently asymptomatic, according to the Republic of Korea Air Force. The base is near a United States Air Force base.The officer had been hospitalized with a fracture at a civilian facility where the first confirmed MERS patient had stayed, before returning to the base.Among the five newly confirmed patients, two of them stayed at the facility as patients where more than 20 had already been confirmed as infected by the first patient.Among the two health care workers who have been newly confirmed as MERS patients, one of them is believed to have been infected by the first patient at the same facility where more than 20 infection cases took place. The other treated the 14th confirmed patient at a medical clinic where the first confirmed patient had briefly stayed as well.The remaining new patient is believed to have been infected by the 16th patient who visited a total of three hospitals while infected, including the one where he stayed with the first patient.As of Thursday morning, more than 700 schools and kindergartens have decided to cancel classes to prevent possible infection among school children. MERS has killed two people since the first case was confirmed on May 20 and led to the isolation of more than 1,300 people.By Claire Lee ( dyc@heraldcorp.com