A panel of experts at the World Health Organization is debating whether the increase in MERS virus cases in the Arabian Peninsula and its global spread amount to a "public health emergency of international concern" that warrants greater awareness and precautions. 

Worldwide, the MERS virus has sickened more than 530, including 145 deaths since September 2012, according to WHO. It was in late March that the 200-cases mark was crossed.

"It's pretty clear we're not seeing all of the cases, we're not hearing about all of the cases and also we're now seeing seeding from places like Saudi Arabia to other countries," said Dr. Michael Gardam, director of infection prevention and control at the University Health Network in Toronto.

"I think for certain parts of the world, in particular Saudi Arabia, I think now is the time given the amount of spread to other countries that they should be issuing travel advisories. That doesn't mean you say you shouldn't go there, but that they should make it very clear that there are potential concerns if you go there, and we should be looking for people coming back, especially if they have symptoms."

Symptoms of Middle East respiratory syndrome include cough, fever and sometimes fatal pneumonia. It is caused by the MERS coronavirus, a cousin of the SARS or severe acute respiratory syndrome coronavirus that killed around 800 people worldwide after first appearing in China in 2002. Coronaviruses are also a cause of the common cold.

Mideast Saudi Virus

An electron microscope image shows novel coronavirus particles, also known as the MERS virus, colourized in yellow. (National Institute of Allergy and Infectious Diseases-Rocky Mountain Laboratories/Associated Press)

WHO said its assistant director general for health security, Keiji Fukuda, will hold a news conference on Wednesday to announce the conclusions of the meeting.

In Canada and the U.S., the advice to the general public remains that the threat is low and standard precautions for a respiratory virus apply, such as frequent hand washing, avoiding someone who is coughing and sneezing, and staying home when sick.

Tuesday’s announcement by health officials in Florida that two Orlando health-care workers are showing symptoms of a flu-like illness serves as a reminder for health-care workers everywhere to be on the alert for potential MERS patients, particularly in those with a travel history to the Arabian Peninsula, Canadian and U.S. doctors say.

"There’s certainly lots of business travel between our country and the Middle East, so I would actually be surprised if we don’t have an imported case or two," said Dr. Mary Vearncombe, who was in charge of infection control at Toronto’s Sunnybrook Hospital during the SARS outbreak.

The case fatality rate for MERS is about 27 per cent, something doctors need to be careful about, Vearncombe said. Fortunately, the virus isn’t efficient at spreading person to person in households.

For health-care workers, masks, eye protection, gown and gloves are recommended when treating patients with respiratory viruses.

MERS Cases

With files from CBC's Kim Brunhuber, Reuters and The Canadian Press