Middle East respiratory syndrome has killed 58 humans since the MERS coronavirus (MERS-CoV) was first detected in 2012—a mortality rate of nearly 50 percent. Researchers have suspected that bats and camels were the source of the virus, and new data published today (October 10) in Virology Journal add weight to the former as the original reservoir of the disease.
“Our analysis suggests that an evolutionary lineage leading to the current MERS-CoV co-evolved with bat hosts for an extended time period, eventually jumping species boundaries to infect humans, perhaps through an intermediate host,” Jie Cui, the lead author of the paper and an evolutionary virologist at the University of Sydney in Australia, said in a press release.
Cui and his colleagues scrutinized the mRNA sequences of the cell surface receptor, DPP4, which MERS uses to break into the host cell. They found a higher ratio of nonsynonymous-to-synonymous nucleotide substitutions among the sequences of DPP4 from five bat species compared to DPP4 sequences in nearly all of the 27 other mammals analyzed—an indication of adaptive evolution, possibly to escape entry by MERS. The findings “accord with the growing body of data that the newly emerged MERS-CoV ultimately has a bat-origin,” the authors wrote in their report.I feel like my excellent Del Rey Books editor Owen Lock in my science-fiction writing days, who when I pitched him on a new idea for a novel, would say: "What's at stake?"
So MERS originated in bats, and I originated in the French Hospital in New York City; how does either fact advance our understanding of the present problem?
Humans and bats rarely interact, even to the extent of getting a bat in one's hair. However MERS got to us, it was through some other intermediary. It's a small scandal that we have yet to find that intermediary.
And that's what's at stake: Something emerged in the environment of the city of Zarqa in the spring of 2012, and especially in its hospital. Within months it had emerged again in a couple of Gulf states and exploded in the Kingdom of Saudi Arabia. Something in all this vast but geographically limited region could infect someone seriously enough to put the person in hospital, where the virus could then flourish.
When SARS did the same thing in 2003, the source was found in civet cats being consumed in "wild taste" Chinese restaurants. Shutting down the sale of the poor creatures effectively shut down the epidemic. When we find the civet cats of the MERS outbreak, we will have a chance of shutting it down as well.
And that's what's at stake in the present problem.