Tuesday 15 July 2014

Middle East respiratory syndrome coronavirus (MERS-CoV) daily numbers...

Because I miss my charts, this is a quick one, made the old fashioned way (Excel and Adobe Illustrator).
MERS-CoV detections by date of illness onset (orange; when available, otherwise date of hospitalization or reporting) or by reporting date only (blue), each day since 22-March-2014. 
Click on image to enlarge.
A few things to note from this chart:

  • I've arbitrarily chosen to bracket the Jeddah-2014 outbreak as starting in the week beginning 17-March-2014 (MERS Week #106) and ending in the week beginning 19-May-2014 (MERS Week #114). There don't seem to be Jeddah-originating cases in the week after that, and case numbers are low (<5/day, similar to the same period in 2013) from then onwards...although this is not an exact science. For example, does one count those cases from the Al Qunfudah cluster that were moved to Jeddah hospitals? But it's a guide.
  • This chart has the daily case numbers (orange) based mostly on the date of illness onset. This highlights (again) the ongoing paucity of recent MERS-CoV detections which is great news for the Kingdom of Saudi Arabia (KSA). The map below previously posted here, does highlight an interesting questions. How are the small number of cases reported in June/July so widespread and where are the infections being acquired from? It's not spring (the camel calving hypothesis suggests human cases take off during the active birthing period; perhaps this is just the "ticking over", non-Spring norm for animal>>human acquisitions?) and there are no hospital outbreaks. Is this community spread? All the indicators we have point away from that. It is also a very busy time in the KSA right now with Ramadan having attracted visitors for some weeks. We have not yet seen cases appearing among those with underlying illness, an indicator or sentinel population for MERS outbreaks because they show the more obvious result of an infection. So these cases must be ongoing sporadic camel (or other animal, including goats which appeared in the recent WHO disease outbreak news) to human acquisition. Right? I'm looking forward to some widespread camel testing results from the KSA and some human seroprevalence studies would be very relevant too. Not sure what's taking so long for the latter to appear.
  • The plot of detection based on date of reporting (blue) is somewhat messed up by the found113 detections for which we have no date breakdown (see here for more detail or search VDU for found113). This means the detection all get assigned into 3-June, the date the KSA Ministry announced them. Yuck. It looks like those details are never going to materialize either. At least, my personal efforts to get date data from Prof Tariq Madani have failed, despite his public assurance that more detailed data could be made available to scientists who wanted it, and the WHO seem to have moved on to posting more contemporary cases in detail, skipping over the same level of detail for the found113.
The very good news is that Ramadan has not coughed up a plague of new MERS cases. The bad news is, we still don't really know the source of the cases that have been continuing to emerge in the KSA. Without knowing that we really don't have a handle on this disease, or this virus, at all.

Location of June/July MERS-CoV detections in the KSA.
Click on map to enlarge.

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