The three camels which have tested positive with #MERS in #Qatar were detected in a barn linked to two confirmed human infections
— WHO (@WHO) November 28, 2013
Further, some very interesting titbits from a Twitter exchange this evening.
Firstly Prof. Marion Koopmans, Head of Virology at the Laboratory for Infectious Diseases of the National Institute of Public Health in the Netherlands confirmed that this was the MERS-CoV and not something requiring lengthy sentences filled with "probable" and "MERS-CoV-like"...
@MackayIM working on it. Qatari's are fast, samples came in last weekend, but yes, confirmed..and that for the most useful conclusions to be drawn from any sequencing being undertaken..
— Marion Koopmans (@MarionKoopmans) November 28, 2013
@arambaut @mackayim Yes, but requires sufficient sequence of sufficient quality. We are working on it
— Marion Koopmans (@MarionKoopmans) November 28, 2013
..but that despite all sorts of great leaps in technology, not to mention in distance-spanning scientific collaborations, things don't just happen overnight.
We should all be mindful that there are many steps between taking a (hopefully adequate) sample(s) from a human or animal, and reaching any useful conclusion about how the molecularly characterized virus might have travelled (human to dromedary, vice versa or via some other vector or intermediate)...
@arambaut @mackayim Yes, but we DO need some time. We are 4 days into the labwork. ;>)
— Marion Koopmans (@MarionKoopmans) November 28, 2013
As Prof Andrew Rambaut, Institute of Evolutionary Biology, University of Edinburgh, noted...
@MarionKoopmans @mackayim Indeed - I don't think people realise how much work it is to sequence these (and how much work to get good seqs).
— Andrew Rambaut (@arambaut) November 28, 2013
And on the subject of whether the new sequences will lead to an indication of which direction this particular cluster of infections is travelling i.e. from human-to-camel or camel-to-human, Prof. Rambaut had this thought on following the viral genome's sequence variations (polymorphisms)...
@MackayIM @marionkoopmans Look for polymorphisms that are not fixed in the putative donor but fixed in the recipient...
— Andrew Rambaut (@arambaut) November 28, 2013
This is all really great to watch. A fast and fruitful collaboration between sample holders and laboratory researchers, expert in their fields.
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| Click on image to enlarge. Those POS for a fragment of MERS-CoV or MERS-CoV-like virus sequence are highlighted in red. Whether there are other intermediates remains to be confirmed. |
At this point, I believe (and it is just a belief) that the camel is looking good for a source of MERS-CoV acquisition by humans. Is it an endemic camel virus? Well, we still have the knowledge that bats seem to harbour a lot of CoVs, and there is that pesky Taphozus perforatus sequence discovered from earlier in the year. It looked an awful lot like a fragment of the MERS-CoV genome. Baboons - I'm holding out for them to be the link between bats and camels...but that is a hope in the absence of any data whatsoever!
Today's confirmation of a cluster of 3 POS camels among 14 represents 21% of the animals POS in a single area.
If we consider this to be human-to-camel transmission, then this would be a much steeper proportion of positives than we normally see when we look at studies of close contacts of human MERS cases. Camels must be very susceptible to MERS-CoV infection because human contact testing just does not show this level of onward transmission. More susceptible to humans? No, I think we're getting closer to confirming that it's a camel-to-human thing...but we are not there yet.
Work continues, but today was a significant day and one in which I give thanks for the ability of people from all over the world to work together towards common goals in preventing human disease.
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