Toronto SARS expert Dr. Allison McGeer arrived in the Middle Eastern country on Wednesday, travelling at the request of the kingdom's government, a source revealed.
The outbreak, which involves at least 13 cases, has ratcheted up worry about the coronavirus, the World Health Organization acknowledged in an update on the virus, which is from the same family as the SARS coronavirus.
"The reappearance of this virus and the pattern of transmission currently being observed in Saudi Arabia increase the level of concern regarding this novel pathogen," the statement said.
"The questions of the exposures that result in human infection, the mode of transmission, the source of the virus and the extent of infection in the community urgently need to be answered and are being actively pursued by the Ministry of Health of Saudi Arabia."
In addition to McGeer, two officials of the World Health Organization were in or travelling to the country to meet with senior officials of the ministry of health in the capital, Riyadh.
"It's likely they will also visit al Hofuf," WHO spokesperson Gregory Hartl said. He would not reveal the names of the WHO personnel.
The news came on the same day as France reported it had confirmed a case in one of its citizens, a 65-year-old man who got sick in late April after travelling to Dubai in the United Arab Emirates. His infection was confirmed May 7.
It was reported that the man was in the Middle Eastern country on a package tour, a fact that suggests his case may help disease investigators in their efforts to track down the source of the virus. That key fact has to date evaded detection.
Piecing together possible exposures with this coronavirus has been tough. Of the 31 confirmed cases, 18 have died. Of the others, many remain in hospital in critical condition, often on breathing machines. So questioning cases about what they did in the days before they fell ill can be difficult or impossible.
But the activities of a tour are generally highly regimented. A schedule should be available outlining where the group went, what type of activities or events they took in, what and where they ate as well as whether they had any animal contacts and what those animals were. With a tour, there are built-in witnesses and likely photos and videos documenting the man's activities.
"I think this could be a very important case," said infectious diseases expert Michael Osterholm.
"I would think that it would be probably one of the best opportunities (to help find the source), because it would be so highly scripted," he added. "Animal contacts, etc., they should know that. ... In this case, they should be able to go back day by day and say: 'Exactly what did you do what day?'
"This is not someone living in the environment. It's not someone who is an animal caretaker. It's not someone who is working in a health-care facility in the area. So it really should give you what we would call more the kind of rare exposure phenomenon."
Saudi Arabia announced last week that it had confirmed a group of seven new cases in al Hofuf, in the eastern part of the country. Five of those patients were already dead when the announcement was made.
At least some of the cases had received care in a dialysis clinic at Al-Moosa Hospital and it appears that some person-to-person transmission of the virus occurred there.
In the days that followed, the numbers in al Hofuf climbed to 13 cases and seven deaths, making it the largest confirmed cluster of infections with the new virus to date.
In April 2012, 13 people in a Jordanian hospital came down with a mysterious illness which was only later recognized as having been caused by the new coronavirus. Stored samples from two fatal cases in that cluster later tested positive for the virus; the WHO considers the 11 survivors probable cases. Ten of these people were health-care workers.
Infections in hospitals played a key role in the spread of SARS during the 2003 outbreak, which is why the WHO and others are keeping such a close eye out for infections in health-care workers or among patients in hospitals.
McGeer, who contracted SARS during the early days of Toronto's outbreak, is head of infection control at Toronto's Mount Sinai Hospital and was heavily involved in the city's SARS response. That experience is likely why the Saudi government consulted her on this outbreak. She was not immediately available for comment on the role she might play in the investigation.
The WHO said at least two of the infections at al Hofuf involve family members of a dialysis patient, suggesting person-to-person spread may have occurred outside the hospital setting too. This "raises a concern about potential broader transmission in the community," the WHO's statement said.
There has been at least one other situation in which the virus is known to have been transmitted person to person — among three members of an extended family in Britain. The first case in that cluster got sick while travelling in Saudi Arabia. There have been several other clusters of cases where person-to-person spread is suspected, including the Jordanian hospital outbreak.
The majority of cases — 23, with 14 deaths — have been reported by Saudi Arabia. The WHO considers the man who sparked the British cluster a Saudi case because he fell ill while visiting there. The two family members he infected are recorded as British cases.
People are known to have contracted the virus in Jordan, Qatar, Saudi Arabia and the U.A.E., Britain, Germany and now France have also seen cases, but they have been in people who were either transferred by air ambulance to European hospitals, contracted the virus while travelling in the Middle East or, in the case of the British cluster, were infected by someone who contracted the virus in an affected country.
Though the existence of the new virus was first discovered late last June, it is still not known how people are becoming infected. The genetic sequence of the virus suggests it probably originated in bats. But the WHO has warned that people looking for the source should not assume exposure to bats or bat excreta are to blame.
The possibility remains that other species of animals are infected and are serving as a bridge that brings the virus to people. Research into the origin of the SARS outbreak suggested a bat coronavirus came to infect some small animals — mainly civet cats — which were sold in live animal markets in China. These animals were the source of the human outbreak.
The Public Health Agency of Canada is also helping in the response to the coronavirus. Spokesperson Stephane Shank says two of the agency's staff are part of an informal working group of technical experts that the WHO has drawn together to advise it on the new coronavirus.
— with files from The Associated PressSuggest a correction