Friday, 21 February 2014

H7N9 deaths jump significantly....

Click on image to enlarge.
Twitter was buzzing this morning with news that several sources had announced a new total number of deaths in human cases of H7N9 infection.

It was not a total surprise that there were more deaths than we had heard about, and that is for several reasons:
  • In Wave 1, Spring 2013 in South east China, there had been a greater proportion of deaths than we have seen in Wave 2. That's seemed unusual.
  • After Wave 1, the proportion of fatal cases (PFC; see background here) sat up as high as 33%. Wave 2's high case numbers but few reported deaths had lowered that to 18% at one point. If the virus hadn't changed and human-to-human transmission had not changed then that was incongruous
  • The media were reporting higher numbers than we had data for in early Feb and in late Jan, Xinua reported 26 deaths in Zhejiang alone for 2014 - this far outstripped any publicly data available
So now we see that the tally is 112 fatal H7N9 cases among people infected with a laboratory confirmed H7N9 virus, since the outbreak began in 2013; that tally includes both waves of human cases. That makes the PFC among the 361 confirmed human cases at 31%. 

So this one new piece of news has bumped up the PFC by 10%. From 1:5 (22% last week) to nearly 1:3 cases dying after acquiring infection. 

Thankfully, H7N9 is not spreading efficiently among humans (or chickens according to reports). But these are numbers to care about.

For comparison, my Excel sheet has 64 cases with data that I can cross-check (I believe that agrees with the FluTracker's count also). 

The last media update I looked at had a tally of 77 fatal outcomes

So we have between 35-48 people have died without any ability for anyone outside China to link them to:
  • their age
  • when they became ill
  • where they were
  • how they may have acquired their infection
  • their sex
  • time to hospitalization and diagnosis
  • length of stay in hospital 
  • what contacts they had and how they have fared. 
I think that this is a ball that has been not just been dropped, but buried in a hole and covered over with feathers. I'm disappointed by such a gaping data loss. And don't get me started about the absence of H7N9 sequences from 2014 cases!

Sources...
  1. SCMP with higher death tallies than public data indicated
    http://www.scmp.com/news/china/article/1425289/january-worst-month-chinas-human-h7n9-outbreak
  2. Xinhua lists 26 deaths in Zhejiang alone for 2014
    http://news.xinhuanet.com/english/china/2014-01/21/c_133060657.htm
  3. VDU blog on missing deaths
    http://virologydownunder.blogspot.com.au/search?q=deaths+h7n9
  4. Mike Coston's Aviann Flu Diary take one the new data, with other sources
    http://afludiary.blogspot.fr/2014/02/chinas-moh-h7n9-fatalities-higher-than.html?m=1&utm_source=dlvr.it&utm_medium=twitter
  5. FluTracker's thread with links to eth WHO report
    http://www.flutrackers.com/forum/showthread.php?p=525996#post525996
  6. China's Ministry of Agriculture report of enlarged H7N9 death tally
    http://translate.google.com/translate?u=http%3A%2F%2Fwww.moa.gov.cn%2Fgovpublic%2FSYJ%2F201402%2Ft20140220_3791429.htm&hl=en&langpair=auto|en&tbb=1&ie=UTF-8
  7. The WHO report under the "vaccines" section
    http://www.who.int/influenza/vaccines/virus/recommendations/201402_recommendation.pdf?ua=1