Coronavirus – Credit CDC PHIL
# 8731
Earlier this week the CDC’s EID Journal published a dispatch on a 2013 family cluster of MERS-CoV infection that began in Qatar and migrated to Tunisia (see WHO Coronavirus (nCoV) Update On Tunisian Cases). This cluster consisted of a 66 year old father, and his two adult children, although initially the father tested negative for the virus.
Volume 20, Number 9—September 2014
Dispatch
Family Cluster of Middle East Respiratory Syndrome Coronavirus Infections, Tunisia, 2013
Fekri Abroug , Amine Slim, Lamia Ouanes-Besbes, Mohamed-Ali Hadj Kacem, Fahmi Dachraoui, Islem Ouanes, Xiaoyan Lu, Ying Tao, Clinton Paden, Hayat Caidi, Congrong Miao, Mohammed Mohammed Al-Hajri, Mokhtar Zorraga, Wissem Ghaouar, Afif BenSalah, Susan I. Gerber, and World Health Organization Global Outbreak Alert and Response Network Middle East Respiratory Syndrome Coronavirus International Investigation Team
AIn 2013 in Tunisia, 3 persons in 1 family were infected with Middle East respiratory syndrome coronavirus (MERS-CoV). The index case-patient’s respiratory tract samples were negative for MERS-CoV by reverse transcription PCR, but diagnosis was retrospectively confirmed by PCR of serum. Sequences clustered with those from Saudi Arabia and United Arab Emirates.
Most readers of this blog are aware that respiratory samples (sputum, swabs, etc.) are normally tested for evidence of viral shedding (usually by rRT-PCR) when active MERS-CoV infection is suspected, and sometimes convalescent serum is collected and checked for antibodies several weeks after infection.
Although primarily thought of as a `respiratory’ disease, MERS-CoV infection is also known to produce severe systemic illness, with the virus showing a decided affinity for the kidneys.
Which opens up a third avenue for MERS-CoV testing; using PCR testing of blood serum to look for signs of viremia (or `viraemia’), aka - replication of the virus in the bloodstream.
As you might expect, all of this gets a bit technical, so who better to take us through the process than Dr. Ian Mackay?
Follow the link to read:
Thursday, 12 June 2014
MERS-CoV in the blood....
The Middle East respiratory syndrome coronavirus (MERS-CoV) is, at its core, a respiratory virus. Well, as far as we know it is anyway. But, like other respiratory viruses (see an earlier post on rhinoviruses), MERS-CoV can be detected in the blood....a so-called "viraemia". In some cases this is identified in other virus infections in parallel with the viral load being generally high, perhaps indicating that virus is replicating beyond the body's ability to contain and control it at the site of initial replication.
Perhaps, and MERS-CoV may be a good example of this, so-called extra-respiratory spread of a respiratory virus occurs when it has a penchant for blood vessel cells (they present its receptor or have something in their cellular machinery that aids virus replication) or some other ability to specifically get beyond the respiratory tract.
