PARIS:  Researchers in Britain and Saudi Arabia said on Friday that gene profiling of the MERS virus had provided insights, but no answer, as to how the mysterious microbe spreads.
Reporting online in The Lancet, the scientists said they had assembled a family tree of the coronavirus causing Middle East Respiratory Syndrome (MERS), using samples taken from 21 patients in Saudi Arabia.
With the exception of a cluster of cases in the eastern town of al-Hasa, the focal point of the outbreak is the Saudi capital, they said.
“These results suggest the circulating virus in Saudi Arabia is centred around Riyadh, with sporadic excursions to other centres,” they said.
The probe reiterated the theory that the virus — called MERS-CoV by scientists — probably leapt to humans from animals.
The genetic history of the virus suggests repeat infections may have occurred since then, but what the animal source was, or is, remains unclear, it said.
Tests are being carried on mammals in Saudi Arabia ranging from camels and bats to goats.
The cluster in al-Hasa, in contrast, shows that viral strains there were closely related, which is consistent with spread from human to human.
The samples in Riyadh have a broad genetic diversity, the paper said.
This could mean that the virus is being transmitted through an animal source that is continuously being brought in from elsewhere, it said.
Alternatively, it may be down to the fact that the capital is the country’s biggest population centre, which makes it more vulnerable to human-to-human transmission of the virus. “Transmission of this virus appears to be more complicated than anticipated,” Alimuddin Zumla, a professor at University College London, who helped lead the Lancet study, said in a press release.–AFP