The new MERS virus, which has infected 64 people and killed 38 of them, is mostly spread in hospitals and it will take special care to prevent bigger outbreaks, experts reported on Wednesday.

An investigation into the outbreak in Saudi Arabia showed 21 people were infected as patients who unknowingly went from one clinic to another, spreading the virus. It can spread quickly in the hospital if strict precautions are not taken – including isolating patients, putting masks on both the patients and the health care workers and strict hand hygiene, the researchers reported in the New England Journal of Medicine.

“We saw transmission (between) health care facilities because people would go from one to another and it would not be recognized,” said Dr. Trish Perl of Johns Hopkins University in Baltimore.

The problem is there’s not a great test yet for the virus so it’s not always easy to tell who has it, Perl and colleagues reported.

The new virus is called MERS, for Middle East Respiratory Syndrome Coronavirus. It is a distant cousin of SARS, the severe acute respiratory syndrome virus that infected 8,000 people globally, killing nearly 800 of them before it was stopped in 2003.

Coronaviruses are a big family and they usually cause common cold-like symptoms in people. But in some cases they can cause very severe infections – and MERS is one of these.

Scientists are keeping a very close eye on MERS. “We cannot afford to have another SARS,” Perl told NBC News. It’s already been reported in Saudi Arabia, Qatar, Jordan, Britain, France, Germany and Italy – carried by travelers. And some of those sick have infected other people in the other countries – notably a French patient who infected a roommate in the hospital.

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Perl and colleagues visited a hospital in Al-Hasa in eastern Saudi Arabia, where one outbreak sickened 23 people in April and May. Out of 217 people living in the same homes as the patients, five became infected, while two hospital workers did.

“A total of 21 of the 23 cases were acquired by person to person transmission in hemodialysis units, intensive care units or in-patient units in three different health care facilities,” Perl’s team wrote.

Perl and colleagues – including Dr. Allison McGeer of the University of Toronto, who was herself infected by SARS in 2003 -- needed to find out how the virus spread. Because tests for MERS are not very accurate, patients had to be tested over and over before there was a positive test, Perl’s team reported.

Once it was clear the virus was spreading, however, hospital officials tightened up their routine and the spread stopped.

“They had aggressive hand hygiene, which is key,” Perl said. “We know that proper hand hygiene reduces respiratory viruses by 30 percent.” They also started better use of alcohol-based hand sanitizer, she said. “These are not particularly difficult viruses to kill,” she said.

Patients with respiratory symptoms were isolated or kept together and away from other patients. Those getting dialysis wore masks and were spread out a bit more than usual from one another. “These are basic tenets for what we would do for influenza or SARS,” Perl said. “People might consider them onerous but they are common-sense things.”

MERS has not been seen in the United States, although a handful of travelers have been tested for the virus. Perl said the facilities in Saudi Arabia weren’t much different from similarly rural clinics in the United States. “The place is clean,” she said. “The technology that was available there was similar to what we might find here.”

The researchers were not able to determine if MERS spreads before people start showing symptoms. They also couldn’t say if the virus was spread in the air, or in droplets that might be spread between people who are very close to one another or by touching surfaces.

"Our investigation showed some surprising similarities between MERS and SARS. Both are very deadly viruses and easily transferred between people, and even between health care facilities," Perl said.

As with SARS, some people seem to spread the virus more easily than others, she added.

Now it is too soon to say if MERS is going to spread as widely as SARS did, Perl says. SARS spread slowly within China for weeks or months before travelers carried it globally. In one notorious instance, an infected traveler became sick and threw up in a Hong Kong hotel. He infected seven other people, who eventually carried the virus to Canada, Vietnam, Singapore and elsewhere in Hong Kong.

It could happen again, Perl says. “We have to be careful because we don’t totally know what to expect,” she said. “The one thing I have learned in this business is that respiratory viruses are very difficult to predict.”

The World Health Organization and the U.S. Centers for Disease Control and Prevention say anyone returning from the Middle East with severe acute respiratory infections should be isolated and tested for MERS. Health care workers who care for them need to use special precautions, including gowns and face masks.



