Friday, 25 December 2015

Avian influenza A(H7N9) virus case data in humans: more chicken scratchings

This is an example of a 2015 case announcement from the World Health Organization (WHO). I think it aims to provide information on some avian influenza A(H7N9) cases that occurred in China.

From WHO Disease Outbreak News (DON) at
http://www.who.int/csr/don/15-june-2015-avian-influenza-china/en/
I suppose it does do that in the most basic sense. Yes, if you were a casual electronic browser to the WHO disease outbreak news site (...get out more!) then you would learn of 15 additional human cases of disease presumably due to H7N9 infection. Twenty percent of these cases died and this happened within a month. 

But consider these questions for a moment:

  1. Why would you visit the WHO to learn of this, if you were not seeking some actual detail and evaluation of risk?
  2. If you were a casual browser, I expect you would come away from this with some out-of-context concerns about a bolus of cases in such a short period, spanning a wide age range and occurring across considerable geographic distance. Should you be worried? Is this the precursor to some larger outbreak? Each difficult to answer from this very small cross-section of information.
  3. These public data are relied upon by some when they write papers or release infectious disease reports - so why not include key - yet deidentified - demographic detail in a line list format - remember MERS-CoV in South Korea anyone? That WHO list [4] was messy [5] but it was a step forward for those outside the WHO network who wanted free, publicly available basic data, quickly
In my opinion, the premier emerging disease tracking and publishing - at least in terms of accessible, basic, rapid, searchable, freely accessible and up-to-date emerging infectious disease information - is the team at FluTrackers. Keep your predictive modelling - I'd trade it all in for a clone army of these guys any day! The FluTrackers line list on H7N9 includes some of these cases[6]...and as you can see in the snippet below, even their scouring of the media from China does not help to fill in the data gaps on these cases...
From FluTrackers' H7N9 line list at
https://flutrackers.com/forum/forum/china-h7n9-outbreak-tracking/143874-flutrackers-2013-15-human-case-list-of-provincial-ministry-of-health-government-confirmed-influenza-a-h7n9-cases-with-links?t=202713 [6]
So why does the WHO bother with this information at all? I can't speak for them. But one reason may be because it is relied upon by those who study and prepare for the emergence of new or re-emergence of old infectious agents.[1] These people consume this sort of information to track what's happening outside their own back yard and to weigh the risks that a new bug may come knocking at the gate thanks to a speedy international plane flight. But when the host country is slow or perhaps even reticent to identify key case details, a knowledge gap emerges and may widen. This particular gap has been growing since 2014's H7N9 3rd wave. Perhaps since the 2nd wave.

When sufficient - or any - detail is lacking, then it comes down to the public to look for any answers they seek...by themselves. In this case, that has been FluTrackers & Co; this source has proven itself very worthy for this and for other viral threat monitoring, but cannot be expected to fill this need indefinitely.[2,3]

H7N9 is a good example of an absence of obvious change to the flow of information that the world's public, citizen scientists and its more professional scientists receive about new infectious threats. And this is all a bit strange because I was sure we'd heard a lot about the need to do much, much better on this sort of tracking and chatting in 2014/5 during one of the biggest modern moments of being "caught with our pants down" - the Ebola virus disease epidemic.

Time and viruses wait for no person. Be faster.

Ho. Ho. Ho.

References...

  1. http://ecdc.europa.eu/en/publications/Publications/RRA-Influenza-A-H7N9-update-four.pdf
  2. http://www.ncbi.nlm.nih.gov/pubmed/24885692
  3. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4140362/pdf/jphr-2012-2-e29.pdf
  4. http://www.who.int/emergencies/mers-cov/MERS-CoV-cases-rok.pdf?ua=1
  5. http://virologydownunder.blogspot.com.au/2015/06/matching-mers-case-identification.html
  6. https://flutrackers.com/forum/forum/china-h7n9-outbreak-tracking/143874-flutrackers-2013-15-human-case-list-of-provincial-ministry-of-health-government-confirmed-influenza-a-h7n9-cases-with-links?t=202713