Unexplained infections with a near 50% mortality rate should never be taken lightly and the latest evidence, from 2 new cases in France, that the new Coronavirus EMC (nCoV EMC – also now called Middle East Respiratory Syndrome Coronavirus (MERS-CoV) [1] ) can be transmitted person-to-person is worthy of note. [2]  However, the circumstances of transmission are unusual.  As with the Manchester/Birmingham cases in the UK in February,[3] transfer has only been seen among people of unknown health status in hospital conditions.  This is clearly NOT person-to-person transmission “on the street” and indicates no real change in the behavior of the virus when compared to what we know already. Importantly it does not indicate adaptation of any kind and the most pressing issue is still the source of these infections and how they were acquired by the primary cases.  It’s pretty clear that the primary host for the virus is a Bat but whether contamination occurs directly or via an animal host, goats and camels have been suggested although I have seen no evidence for them being involved, is wholly unknown.  A clue to the pattern of infection observed might be the evidence acquired over 20 years on another Bat borne virus that causes occasional human infection, Nipah virus. Cases of Nipah infection have been simmering away since its original identification in 1998, killing 21 people this year alone in Bangladesh.[4]  The virus finds its way to man via foodstuffs contaminated with Bat saliva or urine and person-to-person contact has been recorded. Rather like H5N1 avian influenza however it has never become a truly humanized virus and local infections remain the norm. The only reason it is not on the front pages along with nCoV EMC is that i) it is not new and ii) it is not a coronavirus so has no relationship with SARS, the (relatively) recent experience of which provides a spook factor. I am not being blasé about emerging viruses, they are dangerous and risk assessments need to be done to reduce the chance of becoming infected, but they are not a unique occurrence and are likely to continue as they have done in the past. [5]  The current nCoV EMC concern is understandable but there is little evidence to suggest it is any more than an example of one of these occasional zoonotic infections.

The Nipah experience might offer some useful thinking about a possible route for infection, via contaminated foodstuffs consumed widely in the Middle East, fresh dates for example. Intermittent contamination and widespread distribution coupled with a short product half-life would mean this could be very hard to pin down but it is doubtless something epidemiology teams are now considering. It is likely, I think, that evidence from past emerging virus outbreaks has something to say about this one.