NIAIDResearchers may have found a source for the first reported human case of Middle East respiratory syndrome (MERS), which is caused by a coronavirus that has infected more than 100 people in the region and killed 49. A sequence fragment derived from an Egyptian tomb bat matches viral RNA isolated from a Saudi Arabian man who died from the virus in June 2012, according to a report published this week in Emerging Infectious Diseases.
The 182-nucleotide fragment was found in a fecal sample from a bat of the species Taphozous perforatus, which was captured within 7.5 miles of the victim’s home. The bat-derived sequence was identical to the corresponding section of viral RNA isolated from the victim.
But some researchers note that the short stretch of nucleotides is not enough to establish that the bat- and human-derived viruses are one and the same. Marion Koopmans, an epidemiologist at the National Institute for Public Health and the Environment in the Netherlands, told ScienceNOW that the findings indicate that bats are a reservoir of the virus. However, she added, the RNA snippet comes from a relatively non-variable region of the viral genome.
“There’s still potential for it to be relatively distant if we had the complete genome,” Andrew Rambaut, who studies molecular evolution at the University of Edinburgh, told The Canadian Press.
The RNA fragment was likely so short because the bat samples thawed after being opened in customs en route to study coauthor Ian Lipkin’s virology lab at Columbia University. Lipkin noted that while bats may play a role in human MERS, there are likely other missing links in the chain of transmission.
“There have been so many cases of MERS described in the Middle East where we cannot make a direct link with bats,” he told ScienceNOW. “So there is likely to be an intermediate host.”
Some MERS victims have reported contact with camels, which appear to be susceptible to the virus, implicating the animals as potential disease transmitters.