On 28 June, the novel Middle East respiratory syndrome
coronavirus (Mers-nCV) took its 41st victim.
The 49-year-old man, who had been airlifted from Qatar to Guy's
and St Thomas' hospital in September, had been suffering
from kidney failure and
lung damage caused by the virus.
7 July saw two more Saudis lose their lives to the virus. In February of this year there
were only ten
confirmed cases and five deaths, that number now stands at 77
cases and 44 deaths.
Mers-nCV has arisen from a normally benign family of viruses,
because of their crown-like appearance under electron
microscopy. Mers-nCV is far more deadly. Around 50
percent of patients confirmed to have been infected with
the virus have died.
"Most adults [in Europe] will have evidence of being infected by
a coronavirus at some time," says Dr Jake Dunning, a doctor of
infectious diseases at Imperial College London's National Heart and
Lung Institute. A normal coronavirus would usually be
indistinguishable to an ordinary cold.
Reports about the new virus started to appear in September 2012.
Affecting mainly older men with preexisting medical conditions, it
causes Sars-like symptoms, though it should be emphasised that it
is not Sars. These symptoms include shortness of breath, coughing
and fever. More serious symptoms include diarrhoea and vomiting,
severe lung damage and organ failure
All of the initial cases were in the Middle East, particularly
in Saudi Arabia, where the majority of victims have lived, and Jordan, where it
is believed to have originated. Cases have been identified in
France, Germany, Italy, Tunisia, the UK, United Arab Emirates and
Qatar. Unlike with Sars, where the animal "reservoir" source was
identified fairly quickly, we still don't know the "reservoir" of
"We don't know how humans are getting infected," says Dunning.
The virus' nearest genetic neighbour is a bat
coronavirus, but it's not clear if this is the source of
Though there is currently no vaccine, the virus thankfully
doesn't spread easily between humans. Outbreaks have been mainly
confined to hospital settings and family interactions. A study in
England Journal of Medicine examined a cluster of hospital
outbreaks in Saudi Arabia, detailing how the virus spread through
wards following the admission of "Patient A", but in the general
population the virus has had little impact: "we haven't seen
sustained transmission outside of these small clusters," says
On the other hand, it's primarily the serious cases that attract
attention. It's possible that milder, non-lethal infections of
Mers-nCV have occurred in the wider population, but haven't been
spotted. Although it's not clear exactly how the virus spreads, the
evidence suggests that it is from close contact with infected
persons, though infection via contaminated surfaces may also be
Genetic analysis has traced the
evolution of the virus to mid-2011 and a recent report in the Lancet raised the possibility that
Mers-nCV could be dying out. The report attempted to estimate the
reproduction number, which is the number of people that an infected
person is likely to spread the virus to. This suggests that in its
current form, the virus doesn't have epidemic potential.
However, Dunning is quick to urge caution. "In the early days of
Sars, there may have been a similar pattern before it really took
off," he says.
He concedes that Sars took much less time to spread widely,
which suggests that Mers may not do the same, but says that with
millions of people heading to Saudi Arabia in October for Hajj,
there's still a risk that Mers could be spread via international
travel. Air travel famously helped Sars spread across the globe,
infecting 8,000 people and resulting in the deaths of 774 of those
"Those of us who are experienced in outbreaks are not letting
our guard down," says Dunning.