Kingdom's chief scientist says he hopes they will answer questions about how virus passes from animals to humans
Saudi Arabia says it has recruited patients for a crucial study on the source of the deadly MERS virus, acknowledging it is late but pledging more work on the epidemic after international criticism of its slow response.
Scientists and global public health experts have faulted Saudi Arabia's response for allowing the spread of the Middle East Respiratory Syndrome (MERS) virus, which has now killed nearly 300 people inside the kingdom.
Among Riyadh's failings has been the lack of a type of research known as a "case-control" study, which compares the histories of people with a disease to a "control group" of people who do not have it, to try to determine what causes it.
The kingdom's chief scientist, Tariq Madani, said the study was now under way, having so far enrolled the first 10 "cases" - people who had the disease and either died or recovered - alongside 40 "controls" to compare them with. Ideally, the study would look at 20 cases and 80 controls, he said.
He hoped it would at last answer questions about how the virus passes from animals to humans, where it can cause respiratory disease and fever, and kills more than a third of people known to contract it.
The World Health Organisation (WHO) and other critics say the Saudi failure to properly investigate the causes of the disease, including the absence of a case-control study, contributed to the virus taking hold there and spreading via travellers to some 20 countries around the world.
Madani, named two months ago to head a scientific advisory board at a new health ministry Command and Control Centre (CCC) to handle MERS, said the case-control study was a central part of a "180 degree" reversal in policy, to step up the fight against the disease and make the response more transparent.
"(This) should have been done long ago, but unfortunately it wasn't. So it was the top priority research project we started with," he said in a telephone interview from Jeddah.
"It will answer many questions regarding the risk factors for acquiring MERS - particularly in the primary cases where there is no clear source of infection such as contact with somebody else with MERS."
Saudi Arabia sacked its previous health minister in April and his deputy in May as negative domestic opinion and global concern grew about the response to MERS.
Madani said the new control centre at the health ministry was coordinating the response across government departments and laboratories, and with international partners.
"Until two months ago, I was one of the scientists who had a lot of concerns about what was going on in the kingdom - a lack of transparency, the lack of a case-control study, etc," he said.
"I was appointed two months ago to address all of these concerns, and now we have changed 180 degrees. We are fully committed to transparency, our research agenda is open to everybody to comment on and to help with."
To help determine how MERS spreads from animals to humans, the case-control study is designed to exclude "secondary cases" of people who were likely to have caught it from other human patients, Madani said.
"Our target was to identify the primary cases by excluding those who had contact with people with MERS or who visited healthcare facilities, and even those who had contact with somebody who visited a healthcare facility, or those who had contact with somebody who had an unexplained respiratory illness that might have been MERS," he said.
The team conducting the study includes several international scientists - including experts who helped develop the WHO's guidance for a case-control study on MERS, which was issued to affected countries in March.
The WHO's guidance calls for including only adults in the study, and says data should be stored in a secure database in the country in which it is collected and that individuals' identities should be protected.
The 22-page guidance also includes almost four pages of questions that study subjects or their relatives should be asked about contact with animals: For example, whether during a visit to a farm with livestock they fed animals, cleaned animal housing or farm equipment, slaughtered animals, assisted with animal births, milked camels, or kissed or hugged camels.
Madani said the case-control study was the centrepiece of a 25-study research agenda, including analyses of interactions between humans and animals, detailed studies of outbreaks in hospitals, and investigation into what treatment strategies are likely to be the most effective.
"We have developed a research agenda of 25 research projects, and 16 of them are currently underway," he said, adding that some 120 scientists in are working on the MERS projects in the kingdom.
"We are trying to mobilise our resources to address and answer questions that have not been answered until now, and also to give support and the best care to patients with MERS."