Sunday, 13 April 2014

Professor Ali Mohamed Zaki on MERS-CoV: camels a secondary concern to person-to-person spread

There have been a seemingly continual and growing stream of Middle East respiratory syndrome coronavirus (MERS-CoV) cases of late, with a particular emphasis on what seem to be increasing numbers of healthcare worker infections, a possibly younger age group and less severe disease.

Professor Ali Mohamed Zaki, Faculty of Medicine, Ain Shams University, Cairo Egypt recently spoke to this in an MBC 2 TV interview. 

I asked Prof. Zaki by email on Friday if he could cover what he said in that interview. He kindly replied with the following.....
"..more cases in humans appeared in hospitals in Jeddah, which may indicate increased virus transmission from man to man due to mutation in the genome leading to virus adaptation. This event may be associated with loss of some virulence elements in the virus."
This could be a possibility but not one we can check very easily right now because there are very few MERS-CoV sequences, complete or partial, on the public sequence databases from cases in 2014.

Prof. Zaki went on to talk about camels in the context of MERS-CoV clusters of person-to-person transmission seemingly on the rise among this flurry of cases in recent months. Prof Zaki noted that...

"..since the virus now is transmitted easily between humans, the role of camels may become less important."
Still, there was a heartening sign indicating some real intent to prevent the citizens and workers of the Kingdom Saudi Arabia (KSA) from acquiring MERS-CoV infections this week. The Governor of Jeddah, Prince Mishal Bin Majed, ordered a clamp down on camel breeding in the city, removal of camels from the streets and direction on the selling of camel milk.[1] Also something about vegetables, but perhaps best we move on from that one.[1] 

A very hard look at infection control and prevention education and its practices in hospitals and ambulance settings is overdue in the KSA. Also needed are some more detailed molecular investigations into the virus itself. It is essential to monitor this slowly growing epidemic to ensure that the viral culprit hasn't undergone any significant changes. Such change may convey upon it the ability to spread more efficiently among people, perhaps, as Prof. Zaki notes, resulting in less severe pathology. Of more concern though is that enhanced spread, without any change in clicnial outcome will put at much greater risk the sizable proportion of older males with comorbidities that reside in the KSA. 

Or course its possible that the rash of cases we are seeing are just due to:

  • Increased exposure to the source
  • Change(s) in seasons
  • Changes in camel, bat or other animal's breeding habits
  • Changes to tests or testing
  • Changes to the way reporting is conducted. 
One thing is certain though, the quality and depth of information accompanying the KSA Ministry of Health MERS-CoV press releases is as poor as ever, if not worse than usual.

I sincerely thank Prof. Zaki for taking the time to reply to my email. Prof Zaki was instrumental in discovering the MERS-CoV during his time working in the Kingdom of Saudi Arabia. I have previously reviewed his role in this and related issues. [2,3,4]

I also thank Mike Coston for picking up on the TV interview that led me to contact Prof. Zaki.

Further reading...
  1. Camels to be off streets as precaution against MERS
    http://www.saudigazette.com.sa/index.cfm?method=home.regcon&contentid=20140408201249
  2. Happy 1st birthday Middle East respiratory syndrome coronavirus (MERS-CoV)
    http://virologydownunder.blogspot.com.au/2013/09/happy-1st-birthday-middle-east.html
  3. Questions about MERS, MTAs and mistakes.
    http://virologydownunder.blogspot.com.au/2013/08/questions-about-mers-mtas-and-mistakes.html
  4. Dr Ziad Memish discusses MERS in the Kingdom of Saudi Arabia (KSA)
    http://virologydownunder.blogspot.com.au/2013/08/dr-ziad-memish-discusses-mers-in.html