Tuesday, 20 June 2017

Working for health can make you sick....

Below is a quick look at the percentage of total Middle East respiratory syndrome coronavirus (MERS-CoV) cases reported each week that are listed as being healthcare workers (HCWs).



The sources of the numbers used in this graph.

These data are curated by me for this blog in my spare time and are compiled from the Kingdom of Saudi Arabia'a Ministry of Health (MOH) daily reports, the World Health Organization (WHO) disease outbreak notifications (and relatively new line lists) and from the FluTrackers line list

I use the same numbering as FluTrackers use in an attempt to produce at least two lists that agree on numbering and content. 

Some other things to note about this graph..

Each of the pink "spikes" is a percentage calculated by dividing the number of MERS-CoV laboratory confirmed HCW by ALL of the MERS-CoV laboratory-confirmed cases that were reported in that same week... 
Sometimes there might be just 1 HCW and 1 patient - which would give a pretty big looking 50% positive (1 divided by 2). But clearly, it is just 1 HCW. 

So proportion (%) alone is not a whole lot of use sometimes. One needs to know the denominator (the bottom number of a fraction) to get a gauge of how big the problem really is. 

The current June hospital outbreak in Saudi Arabia includes three facilities in Saudi Arabia according to the WHO and the MOH.[1,2] From the 47-year old male reported on the 1st June as an index case in one facility, there have been about 44 secondary MERS-CoV detections (cases) in Riyadh. 

Of the 44 MERS cases, 26 are listed as HCWs; 18 of 25 HCW MERS cases occurring in a single week (week beginning 5th June) and accounting for the 72% spike seen at the end of the graph above. 

Just to confuse things, there were 3 distinct hospital outbreaks that occurred previously,  in April and May, but it's not clear whether they contribute any cases to the June tally.[3]

Why can't we have nice things?

There has been no other successful effort, by anyone, to produce a single public MERS case list with a universally agreed upon numbering scheme that contains useful but deidentified case detail, that everyone could refer to and use. The same applies to the influenza A (H7N9) virus as well. This has only been achieved by public volunteer bloggers; FluTrackers and this blog. Pretty poor when you think on it.

References...

  1. http://www.cidrap.umn.edu/news-perspective/2017/06/who-details-saudi-mers-clusters-outbreak-grows
  2. http://www.who.int/csr/don/13-june-2017-mers-saudi-arabia/en/
  3. http://www.cidrap.umn.edu/news-perspective/2017/06/who-reports-3-saudi-hospital-mers-clusters-new-cases-uae-qatar