Wednesday, 12 February 2014

H7N9 snapdate; the number of surviving and fatal human cases...

Click on image to enlarge.
A quick resurrection of a chart which hasn't been updated in 4-months. 

Interesting that the average/median values have not changed too much except perhaps that the deaths have slid a little further towards the older age band. You can still see the older version on my dedicated H7N9 page here for comparison. 


But please note: there are a number of fatal cases not listed here because they could not be identified. 


I currently have data for 58 fatal cases since Feb-2013. This value is roughly supported by a recent ECDC report so clearly we're all in the dark. But the list may be missing at least 19 cases. Some of those are definitely missing as the total comes from official China sources in 2013 which is not supported by public case data. But in 2014, China's media report have reported a higher fatal case load than we can see from released numbers. 31 deaths in 2014 and 46 deaths in 2013 = 77 total deaths; written 2-days ago in the South China Morning Post


No-one seems to be making consistent note of H7N9 deaths in 2014. 


Sporadic mentions of this total or that total flutter around but little is being confirmed officially and regularly. 


Similarly, toward the end of H7N9's Wave 1, identification of fatal cases became hit-and-miss and they became detached; cases were initially identified by sex, age and locale at illness onset, but not linked to their deaths. 


Apparently the World Health Organisation can only take a passive role here as it awaits case information to be collated form the Provinces and municipalities and passed to Beijing and then it. That;s not a criticism of WHO, but I cannot understand why fatality data are so hard to consistently extract when all the other information is available. 


Its not as though no fatality data are available; there are linked data for 19 deaths in 2014, so why not the rest? 


Why not an assertion that there are not more deaths? 


It's really just about linkage and defining the outcome of the infection. 


Cases don't have to be identifiable to be reported on. 


Cases have already been laboratory confirmed as H7N9 positive. 


And why not summarize hospital discharges while we're about it? That's key to understanding the true case fatality ratio (CFR) rather than the proportion of fatal cases (PFC defined here) which, unlike the CFR, does not require knowledge of the entire course of the clinical disease to be calculated.


It is always about data and communication thereof when we seek to understand emerging infectious diseases and outbreaks. Don't have it, can't fully understand what's happening.


Sources...

  1. South China Morning Post article
    http://www.scmp.com/news/china/article/1425289/january-worst-month-chinas-human-h7n9-outbreak