The doctor who discovered a new Sars-like virus says it will probably trigger an epidemic at some point, but not necessarily in its current virulent form.
The new strain of coronavirus (nCoV) that Ali Mohamed Zaki found last year, related to one that caused the outbreak of Severe Acute Respiratory Syndrome (Sars) in 2003, has killed at least 18 people in the Middle East and Europe.
On Sunday, the World Health Organisation said it seemed likely the new virus, which can cause coughing, fever and pneumonia, could be passed between humans, but only after prolonged, close contact.
Zaki, an Egyptian virologist who identified the new virus last June in a patient at the hospital where he was working in Jeddah, Saudi Arabia, noted in a telephone interview on Monday that no one else at that hospital had been infected at the time.
Hospital cases of human-to-human transmission
More recently, there has been a cluster of cases in a hospital in Hofuf in Saudi Arabia's Eastern province, as well as a case of transmission between two patients sharing a hospital room in France.
Zaki, now working at Ain Shams university in Cairo, said the virus was probably mutating. "From what is going on, it seems it is going step-by-step to become more easily transmitted," he told Reuters.
But he said doctors and authorities were in a better position to deal with an outbreak than they had been with Sars because the new virus had been identified relatively early:
"Now we have the virus before the epidemic happened - and I think it will happen - and we have tools to diagnose it."
Lessons of Sars
Sars emerged in Asia and took several months to mutate into a highly contagious form, eventually killing 775 people as it swept across the world in 2003 before being contained by isolation measures and a broad public health campaign.
Zaki noted that it was unclear whether the new virus, which has been fatal in more than half of the 32 confirmed severe cases so far, would still remain as lethal if it became more contagious.
But he said authorities should prepare for the worst and apply standard infection controls such as isolation, just as they did with Sars, noting that Saudi Arabia has a large population of expatriate workers who could spread the disease around the world.
Furthermore, Saudi Arabia draws millions of pilgrims to the Muslim holy cities of Mecca and Medina for the annual haj pilgrimage, which next takes place in October.
Virus spreading outside Saudi Arabia
"The possibility of transmitting the virus outside Saudi Arabia? I think, yes, there is a great possibility because many people are working in Saudi Arabia, many people are visiting Saudi Arabia for religious tourism," Zaki said.
Michael Baker, of the department of public health at the University of Otago in Wellington, New Zealand, agreed that the new virus could turn into a serious threat.
"The arrival of Sars in 2003 reminded us that entirely new human infections can emerge without warning and develop into global epidemics that may be difficult to control," he said in an emailed comment. (Additional reporting by Mohamed Zaki in Cairo and Kate Kelland in London; Editing by Kevin Liffey)