Friday, 20 June 2014

Ebola Virus Disease: Country contributors in 2014 West African outbreak...

Data are based on WHO DONs (see latest, [1]). Lines use the numbers on the vertical  axis on the left. The percentages are the proportion of fatal cases at the time point indicated.
Click on image to enlarge.

As the Ebola Virus Disease (EVD) outbreak in West Africa continues [1], and grows larger, I thought it worth looking at which countries have contributed cases lately. 

  • In late May, Guinea started to see a new, and since then steady, ascension in the number of suspected / probable / confirmed cases and and deaths. 
  • In early June, a big jump occurred in Sierra Leone. 
  • In Liberia there was a rise not in cases, but in fatalities; for a while Liberia had an unusually low proportion of fatal cases (PFC), at just 8%, then something happened to the numbers and it climbed to the higher proportion we expect from Ebola virus.

As I noted last night,[2] and Maia Majumder has also noted on her blog [3] and via a very nice story by the Toronto Star's Jennifer Yang,[4] the PFC for this outbreak is lower than that seen in a number of previous EVD outbreaks (see last night's post for related charts from me [2]). In fact it has been lower than that from other outbreaks at all preceding data points in 2014. Of course this lower PFC, still sitting at a horrible 64%, may just be an artefact of the outbreak not being over yet, and the dust probably still being in the air and yet to settle. 

The PFC may rise as more information is gathered and testing completed, post-outbreak. It it may also be that due to the quick deployment of experts in healthcare, education and laboratory analysis, and perhaps new or different supportive methods, that this outbreak is not taking as many lives as previous outbreak have. But I can't speak authoritatively on any of that.

A reminder:
The chart above, as with all on VDU, is made for general interest only. It is also freely available for anyone's use, just cite the page and me please. It may be that I have misinterpreted the language in the reports (sometimes a little tricky to wade through) or miscalculated some totals based on the way data have been presented. 
There are very country-specific differences in what gets presented to/via the World Health Organization's Disease Outbreak News which make this process less clear than it could be. I recommend you have a read and compare the data from each of the 3 countries for yourself to understand these issues. 
As I've talked about previously,[5] these numbers are all volatile for a variety of reasons, some Ebola-specific, so regard this chart for its trends only.

References...

  1. Ebola virus disease, West Africa – update | 18-June-2014
    http://www.who.int/csr/don/2014_06_18_ebola/en/
  2. West African Ebola virus disease (EVD) outbreak flares up in late May and in early June...
    http://virologydownunder.blogspot.com.au/2014/06/west-african-ebola-virus-disease-evd.html
  3. Ebola 2014: Fatality & Lab-Confirmation Charts
    http://maimunamajumder.wordpress.com/2014/06/19/ebola-2014-fatality-lab-confirmation-charts/
  4. The Ebola outbreak that refuses to die
    http://www.thestar.com/news/the_world_daily/2014/06/the_ebola_outbreak_that_refuses_to_die.html
  5. Ebola virus disease and lab testing...http://virologydownunder.blogspot.com.au/2014/04/ebola-virus-disease-and-lab-testing.html