A "SARS-like" virus that has sparked a health alert by killing nine of the 15 people known to have contracted it infects the body via a docking point in lung cells, a study said Wednesday.
Tests on lab cells have highlighted a key entry point for the new virus and suggest bats may be a natural reservoir for it, investigators said.
The novel virus has been designated hCoV-EMC, meaning human coronavirus-Erasmus Medical Centre, after the Dutch health institution that spotted it.
First detected last year, it is a cousin of Severe Acute Respiratory Syndrome (SARS), which triggered a scare 10 years ago when it erupted in Southeast Asia, leaping to humans from an animal host.
But hCoV-EMC appears to be more lethal, killing nine out of 15 patients who have been treated for it in the Middle East and Britain. Multiple organ failure, especially the kidneys, has been a hallmark of the disease.
Reporting in the journal Nature, virologists at EMC said the virus latches onto a receptor called DPP4 on smooth cells in the airways.
The common pipistrelle bat shares the same receptor, they said.
The finding points to bats as a natural source for the virus, although it is also theoretically possible that humans transmit the virus to bats, the study said.
And, the paper cautioned, it is also possible that other animal species act as an intermediary between bats and humans.
The discovery opens up pathways towards a potential vaccine or drug to combat hCoV-EMC, the researchers said.
In a commentary also carried by Nature, US microbiologists Tom Gallagher and Stanley Perlman said that on present evidence, hCoV-EMC "can be transmitted from human to human, (but) fortunately this seems to occur infrequently."
Further work should determine whether the disease "is truly rare and always severe, or alternatively, is widespread but generally mild and therefore not detected."