The mysterious new coronavirus that emerged in the Middle East and has killed 11 people is potentially more deadly than Sars and also more "promiscuous" - able to infect many different species - University of Hong Kong research has found.
Unlike Sars (severe acute respiratory syndrome), the new coronavirus can affect many different organs in the body and kills cells rapidly, the researchers say.
The source of the new infection is still unknown, but the virus appears to have originated in bats, a team of European experts wrote in the journal mBio.
The HKU research listed animals including monkeys, pigs, civet cats and even rabbits that could be hosts of the virus before it found its way to humans. Lead researcher Yuen Kwok-yung, a microbiologist, said this meant the source of human infection would be difficult to trace.
The World Health Organisation announced yesterday that the disease had killed two more people - a 73-year-old from the United Arab Emirates and a Briton who had visited Saudi Arabia and Pakistan - bringing the death toll to 11. The WHO has confirmed 17 cases to date.
Yuen told the South China Morning Post that the virus could cause a deadly pandemic if it mutated further. "It could be more virulent [than Sars]", he said. "The Sars coronavirus infects very few human cell lines. But this new virus can infect many types of human cell lines, and kill cells rapidly."
The findings, tested in human cell lines, suggest the virus could cause widespread organ infection. It could attack the lower airway, liver, kidneys and intestines as well as tissue macrophages - cell clusters that "eat" bodily debris such as dead cells.
The report, published by the Journal of Infectious Diseases this week, says the new virus "is markedly different" from the other non-Sars human coronaviruses that usually have little ability to move among different cells, and cause self-limiting upper respiratory tract infections.
This may explain why patients with the new coronavirus can suffer multiple organ failure, resulting in a high mortality rate of 56 per cent - in contrast to 11 per cent for Sars.
Yuen said: "The Sars coronavirus infected very few animal cell lines. It was finally traced to bats and civets. But we may have a very hard time, as this new virus seems to be much more promiscuous."
Yuen said, however, that the new virus did not appear to be very infectious, as it tended to infect lower respiratory cells instead of upper respiratory ones like Sars, but this pattern might change as the virus mutated.
"We still have a lot to do before we can learn more about this virus," Yuen said. "Cell line cultures and even animal models may not completely reflect what [it] can do to humans. But this is certainly another step forward."
The Health Department yesterday held a "desktop drill" to test the government's preparedness for a possible outbreak of novel coronavirus.
Additional reporting by McClatchy-Tribune