Monday, 5 May 2014

Ebola virus disease (EVD) West Africa update for 02-May, WHO-AFRO update...

Click on image to enlarge.
Thankfully the latest World Health Organisation update includes figures for Liberia. The last West Africa update did not, so I didn't post a chart.

Summary..

Total suspected/probable/confirmed cases: 244
Total suspected/probable/confirmed deaths: 162 (66.4%)
Total lab confirmations: 133 (54.5% of 227)

These figures are very important for two reasons...


Firstly they show a drop in suspect/probable cases after data scrubbing by the Liberian Ministry of Health and Social Welfare. This reinforces that the outbreak is being well controlled.;The date of isolation of the most recent confirmed cases is 30-April from Conakry and Guekedou (Guinea).


Secondly there has been a concomitant rise in the proportion of fatal cases of EVD due toZaire ebolavirus (see the percentages above the orange line in the chart). This is not because the numbers have jumped, it's because the denominator has shrunk for the relevant calculation:

No. EVD fatalities/No. total susp/prob/conf cases.
We've known this rise in proportion was coming because it was highly likely that case numbers would change as the dust settles and the susp/prob EVD patient numbers get discarded because they are found to be infected by something else; clinically similar disease, but not because of infection with Zaire ebolavirus. I've written about it previously if you'd like some background.

With the use of more antibody testing, the numbers will continue to change, as they always do in outbreaks.

This will be my last update on this outbreak linked to the WHO-AFRO announcements unless anything major happens.

A reminder - the chart above is made for general interest. It may be that I have misinterpreted the language in the report (sometimes a little tricky to wade through these reports) but the trends should still be informative even if a number or data point is out of place.



Sources...

  1. http://www.who.int/csr/don/don_updates/en/
  2. http://reliefweb.int/report/liberia/unicef-liberia-ebola-virus-disease-sitrep-20-2-may-2014
  3. http://virologydownunder.blogspot.com.au/2014/04/ebola-virus-disease-and-lab-testing.html