A new virus in the Middle East has sickened more than 180 people and killed an alarming 43 percent of them. But scientists haven't been sure where the virus originates or how people catch it.
Scientists have gotten close to pinning down the origin of Middle East Respiratory Syndrome, a dangerous respiratory disease that emerged in Saudi Arabia 17 months ago. It turns out the MERS virus has been circulating in Arabian camels for more than two decades, scientists report in a study published Tuesday.
So far MERS has sickened more than 180 people, killing at least 77 of them — an alarming 43 percent. But scientists haven't been sure where the virus came from or how people catch it.
A report in the journal mBIO suggests the virus is ubiquitous among Saudi Arabiandromedary camels, the one-humped variety. The animals get the virus when they're young, and it often doesn't make them sick.
"We now know the answers to several questions," says the report's senior author, Ian Lipkinof Columbia University. "First, this virus infection is very common in camels. It probably occurs early in these camels. So this is a reservoir that is constantly replenishing itself. It can go directly from camels to humans, with no need for adaptation in another animal. And there's a lot of virus."
"This really confirms that this is a camel virus," says virologist Marion Koopmans of Erasmus University, who wasn't involved in the study.
Koopmans and her team had previously found the MERS virus in camels as far afield as Africa and the Canary Islands. But the current study, she says, ends the discussion about whether camels get the virus from people. "It shows this virus is circulating in camels, period," Koopmans tells Shots.
At the same time, the new data leave other questions unanswered and even deepen some of the mystery around MERS.
The symptoms of MERS — often a life-threatening lung infection — can look similar to regular pnuemonias. So one question is whether people have been getting the virus for decades without anyone noticing or diagnosing it.
"What argues against that," Koopmans says, "is genetic sequence data from viruses picked up in people indicating that the virus emerged around mid-2012, not before that. That does not add up to infections having gone on for a long time, but that's still an open question."
Via Dr. Stefan Gruenwald