The death toll from Middle East respiratory syndrome, or MERS, rose to 19 Tuesday in South Korea as the number of infections increased by eight to 162, Yonhap News Agency reported. Of the three deaths Tuesday, two of the individuals had no prior medical condition, including the youngest person to die of the disease so far, a 49-year-old. Four of the 19 dead had no prior medical condition.

The disease has put South Korea on edge. Since patient zero walked into a hospital with a cough and a fever about a month ago, 2,200 schools were shut down -- though just 475 remain closed -- and as many as 2,800 people have been isolated to stop the spread of the respiratory disease. People are avoiding public spaces like malls and movie theaters, and when they do go out, they make sure to wear thin surgical masks covering mouth and nose.

Patient zero was a 68-year-old man who had traveled recently to the Middle East. He reportedly had been on a trip to four countries in the region. As of June 9, there were more than 1,000 cases of MERS in Saudi Arabia since 2012 when the disease was first identified.

The 2012 MERS outbreak in Saudi Arabia can be traced back to a single-humped camel in the Arabian peninsula. Before the 2012 diagnosis, preserved biological material can place a camel with the disease as far back as 1992. There is no vaccination for the disease, which kills around 36 percent of those it infects. The outbreak isn't isolated to the Middle East and South Korea, either: it was reported Tuesday a man died from the disease in Germany.