SEOUL (Reuters) - South Korean health officials on Sunday reported 14 more cases of Middle East respiratory syndrome (Mers), bringing the total in the country's outbreak to 64, and said a fifth person infected with the virus had died.

South Korea's outbreak of the often-deadly Mers virus, first reported on May 20, is the largest outside the Middle East, prompting public fear and questions over the government's initial response.

The patient who died was a 75-year-old man who had been in the same Seoul hospital emergency room where a total of 17 people, including two medical staff, are believed to have been infected with Mers, South Korea's Health Ministry said.

Of the 14 new cases, 10 were at the same Seoul hospital. All of the confirmed South Korean infections have taken place in health-care facilities, officials have said.

First identified in humans in 2012, Mers is caused by a coronavirus from the same family as the one that triggered severe acute respiratory syndrome. But Mers has a much higher death rate at 38 per cent, according to World Health Organization (WHO) figures.

The South Korean Mers outbreak is traced to a man who returned from a business trip to the Middle East. His wife, who was also infected, has recovered and became the first in the outbreak to be discharged from the hospital, officials said on Saturday.

There has been no sustained human-to-human transmission, but the worst-case scenario is the virus changes and spreads rapidly, as Sars did in 2002-2003 when it killed about 800 people around the world.

South Korea's new cases bring the total number globally to about 1,208, based on WHO data, with at least 444 related deaths.