SEOUL—It may be called the Middle East respiratory syndrome (MERS), but at the moment the respiratory disease is spreading far more fear in East Asia than in the Middle East. An outbreak of the deadly virus has set many people in Korea on edge, especially since it is related to SARS, which took a heavy toll in Asia in 2003 and killed more than 700 people worldwide. More than 1000 schools and kindergartens here have temporarily closed, many people are wearing facemasks, and camels in several zoos have been quarantined.
None of these measures make much sense, scientists say. The index case infected health care workers, patients, and family members at the hospitals he was treated at, but nothing suggests there is a risk of being infected at school or on the street. Although camels are believed to be the main reservoir for the virus in the Middle East, the virus was brought to Korea in May by a 68-year-old business traveler who had visited four Middle Eastern countries; there is no reason to believe camels in Korea are spreading the disease. “People need to understand that this virus is not circulating in the community in Korea,” says Peter Ben Embarek, the World Health Organization’s (WHO's) point person on MERS. (To epidemiologists, "in the community" means outside hospitals.)
Korean authorities have tallied 36 MERS cases, including three fatalities. WHO has praised Korea for continuously sharing the number of new patients as they are diagnosed, but there has been little information to put those numbers into context. "There is an urgent need to provide the public with background information about this disease that is new and mysterious to them,” Ben Embarek says. In Saudi Arabia, where the virus does occasionally spread outside hospitals, schools are open and no one is panicking, he points out. "Numbers are important, but we have to do more than that, both at the national level and the international level."
Communication appears to be a problem all around. While politicians comment frequently on the outbreak, few scientists involved have spoken out publicly. When the Korean Centers for Disease Control and Prevention (KCDC) was faced with a barrage of criticism and questions today, its response was to close its Twitter account to the public. Numerous emails from ScienceInsider to KCDC and the Ministry of Health have gone unanswered over the last few days. The fact that two of three fatal MERS cases weren't diagnosed until after the patients' deaths has not inspired confidence either.
Ben Embarek says that the virus has been sequenced in Korea and that the sequence may soon be uploaded into a public database so that researchers can compare it to MERS viruses isolated elsewhere and spot any differences. That should happen soon, says Hakim Djaballah, the head of the Institut Pasteur Korea. “There is supposed to be a sequence, but it is nowhere to be found," Djaballah says. Attempts by Malik Peiris at The University of Hong Kong to sequence the virus from a Korean patient who traveled to China have been unsuccessful, Djaballah says. “There is very little virus from that patient.” (Peiris could not immediately be reached for comment.)
Djaballah suspects that mutations in the virus are helping it spread more easily than before. “Thirty-six cases in less than a month is a lot. This virus seems to be highly contagious,” he says. Others are less convinced of that. “I’m not expecting any big changes,” says virologist Christian Drosten of the University of Bonn in Germany. One reason: Unlike other RNA viruses, MERS has proofreading enzymes, meaning its genome changes very little over time. And even if there was a change, it would not be immediately clear how important it is to the spread of the virus, Drosten warns.
In tweets this morning, epidemiologist David Fisman of the University of Toronto in Canada said suspicions of mutations crop up often when MERS spreads rapidly, but rarely pan out. Major hospital outbreaks have happened before without any apparent changes in the virus's genetic material.
Without sequence information, scientists have one other clue to go on: the first Korean patient. If the source of his infection can be found, and it turns out to be something other than camels, that would be a hint that Korea is really battling a new strain. The man visited Saudi Arabia, Qatar, the United Arab Emirates, and Bahrain; experts have retraced his steps in three of these countries in detail but nothing indicates that he had contact with camels or other animals, Ben Embarek says. "At this point in time it is still a mystery how he got infected.”
Update, 4 June, 11:30 p.m.: ScienceInsider has received a reply about sequencing the virus from the Korean CDC: "We have successfully isolated the virus, and full genome sequencing of the isolate has been completed. We are planning a press release later today. We shared our full sequence with U.S. CDC for the analysis and will send our samples today to U.S. CDC.”