Published Date: 2013-05-16 16:30:42
Archive Number: 20130516.1717833
Date: Wed 15 May 2013
Source: Journal of Virology [summ., edited]
http://jvi.asm.org/content/early/2013/05/08/JVI.01244-13.abstract
[Ref:
de Groot RJ and members of the ICTV Study Group of the ICTV: Middle
East Respiratory Syndrome Coronavirus (MERS-CoV): Announcement of the
Coronavirus Study Group. J. Virol. doi:10.1128/JVI.01244-13]
----------------------------------------------------------------------
During
the summer of 2012, in Jeddah, Saudi Arabia a hitherto unknown
coronavirus was isolated from the sputum of a patient with acute
pneumonia and renal failure. The infection appears to be geographically
linked -- at least for now -- to the Middle East, in particular the
Arabian Peninsula.
Since the initial discovery, isolates of the
virus have been described in the scientific literature, databases, and
popular press under various names (such as, human betacoronavirus 2c
EMC, human betacoronavirus 2c England-Qatar, human betacoronavirus 2C
Jordan-N3, betacoronavirus England 1) with novel coronavirus (NCoV) as
the one used most often. As this lack of uniformity in virus
nomenclature complicates communication both in the research field and
with health-care authorities, governments and the general public, the
Coronavirus Study Group (CSG) of the International Committee on Taxonomy
of Viruses (ICTV) took the lead to address this issue. After careful
consideration and broad consultation, the CSG has decided to call the
new coronavirus "Middle East Respiratory Syndrome Coronavirus"
(MERS-CoV).
This name is endorsed by the discoverers of the virus
and other researchers that pioneered MERS-CoV studies, by the World
Health Organization and by the Saudi Ministry of Health. We strongly
recommend the use of this name in scientific and other communications.
New MERS-CoV isolates or variants detected by RT-PCR may be provided
with an affix, analogous to convention in influenza virus nomenclature
(host/country of origin + strain identification number/year; such as,
MERS-CoV Hu/Jordan-N3/2012).
Within the subfamily _Coronavirinae_
(family _Coronaviridae_), this novel virus is a representative of a new
yet-to-be established species in lineage C of the genus
_Betacoronavirus_, which currently only includes the species
_Tylonycteris bat coronavirus HKU4_ and _Pipistrellus bat coronavirus
HKU5_. The novel coronavirus seems most closely related to as yet
unclassified viruses from insectivorous European and African bats in the
_Vespertilionidae_ and _Nycteridae_ families, respectively. The
epidemiological data available suggest that the infection is primarily
zoonotic in nature. [Interested readers should access the original
document to view the phylogenetic relationships among members of the
subfamily _Coronavirinae_ and the relative taxonomic status of MERS-CoV.
- Mod.CP]. A rooted Neighbor-Joining tree was generated from amino acid
sequence. The tree shows the four main monophyletic clusters,
corresponding to genera _Alpha-, Beta- Gamma- and Deltacoronavirus_, and
the position of MERS-CoV.
The scarce epidemiological data
available suggest that the infection is primarily zoonotic in nature
with limited human-to-human transmission. From what is already know of
coronavirus biology and from the accumulating evidence for this
particular virus, bats appear to be the natural host, and it would be
tempting to assume that these animals are also the immediate source.
However, this is difficult to reconcile with the fact that most patients
were unlikely to have been exposed directly to bats, or with the close
genetic relationship between the human isolates, indicative of a recent
bottleneck. A more likely scenario is that a single variant from a
spectrum of related betacoronaviruses in bats successfully crossed over
to and rapidly established itself in (an) intermediate animal host
species (at least in the Middle East), with subsequent incidental
spill-over into the human population. Such spill over events would be
facilitated through frequent intermediate host-human interactions and
perhaps through viral adaptations acquired during the initial species
jump. Although at present, there is no evidence for sustained community
transmission, the obvious concern is that the virus may take the next
step and adapt to efficient human-to-human transmission.
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[Interested
readers should access the original document to read the full text and
view the illustration showing Phylogenetic relationships among members
of the subfamily _Coronavirinae_ and the taxonomic position of MERS-CoV,
available via http://jvi.asm.org/content/early/2013/05/08/JVI.01244-13.abstract.
As
the epidemiology and host preference of this virus are still
incomplete, it seems prudent to refrain from labeling MERS-CoV as a
"human coronavirus", at least for the time being. Accordingly,
henceforth ProMED-mail will adopt the new nomenclature recommended by
the Coronavirus Study Group of the ICTV. - Mod.CP]
http://www.promedmail.org/direct.php?id=20130516.1717833
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