In fact, they argue that what is different here is that cases are being reported thoroughly and promptly by Korean authorities and in the local media. That has not been the pattern with outbreaks in Middle Eastern countries where the virus originates.
"I think we're all aware of the fact that we're seeing this in much more real time than we have those (outbreaks) on the Arabian Peninsula," said Michael Osterholm, who heads the University of Minnesota's Center for Infectious Diseases Research and Policy and who helped investigate MERS outbreaks in the United Arab Emirates.
"That could add to the sense that there's something different happening here."
As of late Monday, 25 cases had been confirmed and two infected people had died. One person who was a contact of a case broke quarantine last week and travelled via Hong Kong to southern China. Once there, he was diagnosed with the disease.
The outbreak was sparked when a man who had travelled in four Middle Eastern countries returned to South Korea in early May. He was not sick at the time, but by mid-month was symptomatic and seeking care. He was seen at two clinics and in two hospitals before being diagnosed with Middle East respiratory syndrome.
Since then a steady stream of secondary cases has materialized including patients who shared a hospital room or a ward with the first case, family members who visited those patients and health-care workers. On Monday, Korean officials announced they had found some tertiary cases — people infected not by the first man, but by patients he had infected.
Still, all this has been observed before, said Peter Ben Embarek, the World Health Organization's point person for MERS.
"We have seen many of these similar hospital outbreaks in KSA (the Kingdom of Saudi Arabia) and the Emirates," he said. Those two countries have recorded the vast majority of the nearly 1,200 confirmed MERS cases to date.
In fact, Ben Embarek noted there is currently a hospital outbreak in the Saudi city of Hufof, and the case count there is steadily rising. "In a sense it's not very different."
Ben Embarek noted South Korea has agreed to share viruses from its outbreak so that scientists can look to see if genetic changes might be responsible for the virus's behaviour.
MERS is caused by a coronavirus. It is related to the virus that caused SARS, which jumped from animals to people and triggered a large international outbreak in 2003. Toronto was the site of one of the largest SARS outbreaks, and was the only location outside of Asia to record hundreds of cases.
Since MERS first emerged three years ago, there have been fears the virus would take off like SARS did, sparking widespread disease. But although occasional cases have been exported — to France, Britain, the United States and Germany among other countries — there hasn't been a substantial outbreak outside the Middle East until now.
It is important to investigate the South Korean outbreak, because it could signal something has changed, said Dr. Allison McGeer, an infectious diseases expert. But McGeer said, so far, she thinks South Korea is experiencing what Middle Eastern countries have seen with hospital outbreaks.
"It's a coronavirus. Something bad could be happening. But I haven't seen anything in this yet that says to me anything other than 'Oh, shoot, another hospital outbreak,'" said McGeer, who heads infection control at Toronto's Mount Sinai Hospital.
McGeer battled SARS, surviving a bout with the virus. In 2013, she travelled to Saudi Arabia to investigate and help contain a large hospital outbreak in the city of Al-Ahsa.
That outbreak, which McGeer described as "really well managed", produced around 30 cases. And a huge surge of cases in Saudi Arabia in April and May of 2014 was fuelled by much larger hospital outbreaks in Riyadh, she said.
The numerous hospital outbreaks that have occurred have taught the world how to cope with MERS.
"There's very good evidence now from multiple countries in the Middle East that MERS outbreaks are containable," McGeer said.
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