Friday, 11 April 2014

When 2 - 2 = 2: Ebola case numbers in Sierra Leone

I've been having a little trouble following some aspects of the World Health Organization's (WHO) updates on the Zaire ebolavirus outbreak. There have been a few things - tiny little things - that have made it more confusing for a simple chap like me to track. One of them follows.

Don't get me wrong; this is not a criticism of the fantastic job the social comms team (@HaertlG, @setiogi and @MonikaGehner and no doubt many others I am completely ignorant of) have been doing. I've openly congratulated these guys before, and do so again here; they get so much information out on so many topics to so many endpoints...staggering. The 2014 #ebola communication has been an stunning process/event/big-word-full-of-respect-awe-and-bigness to behold from the outside looking in. It should be a shining example of a multifaceted social media education, updating and mobilisation campaign.

Tonight however, I write about the case numbers from Sierra Leone...and I'm essentially "typing out loud" to work through my confusion here so I forgive you for reading no further.

Lets go back (wavy hands)...


Ebola virus disease, West Africa – update

WHO, 01-Apr-14
The Ministry of Health of Sierra Leone is maintaining a high level of vigilance following the deaths of 2 probable cases of EVD in one family who died in Guinea and their bodies repatriated to Sierra Leone. To date, active surveillance activities have identified no new suspected cases and all contacts of the deceased have remained well.
http://www.who.int/csr/don/2014_04_01_ebola/en/


Ebola virus disease, West Africa – update
WHO, 02-Apr-14
There has been no change in the situation in Sierra Leone following the deaths of 2 probable cases of EVD in one family who died in Guinea and their bodies repatriated to Sierra Leone. As this is a rapidly changing situation, the number of reported cases and deaths, contacts under medical observation and the number of laboratory results are subject to change due to enhanced surveillance and contact tracing activities, ongoing laboratory investigations and consolidation of case, contact and laboratory data.
http://www.who.int/csr/don/2014_04_02_ebola/en/


Ebola virus disease, West Africa – update

WHO, 05-Apr-14
There has been no change in the situation in Sierra Leone following the deaths of 2 probable cases of EVD in one family who died in Guinea and their bodies repatriated to Sierra Leone. The office of the Chief Medical Officer (CMO) is coordinating all operations involving suspected cases of Ebola as well as the follow-up investigations. Enhanced surveillance and public education activities are continuing.
http://www.who.int/csr/don/2014_04_05_ebola/en/


Ebola virus disease, West Africa – update

WHO, 07-Apr-14
There has been no change in the epidemiological situation of EVD in Sierra Leone. The Ministry of Health and Sanitation of Sierra Leone has confirmed that 2 suspected cases of viral haemorrhagic fever are laboratory confirmed as Lassa fever which is endemic in Sierra Leone.
http://www.who.int/csr/don/2014_04_07_ebola/en/

Ebola virus disease, West Africa – update
WHO, 10-Apr-14
Although the epidemiological situation in Sierra Leone remains unchanged, the Ministry of Health and Sanitation (MOHS) continues to lead intensive EVD preparedness activities.
http://www.who.int/csr/don/2014_04_07_ebola/en/


Okay. Cool. So what was all that for?

WHO's super-human Tweeter and communicator, Gregory Härtl (also called Head of Public Relations/Social Media for the WHO) posted a Tweet today...

What I didn't understand was where these 2 cases from Sierra Leone had come from? See-toldya I was a simple chap.

So by listing them out, it seems they must be the 2 suspected cases - highlighted in yellow in the 07-Apr update above. 

They were 2 cases distinct from the the 2 fatal EVD cases in Sierra Leone. As it turns out those 2 fatal cases will forever remain "probable EVD cases" because they died and were not sampled. As Gregory Hartl Tweeted...
If you'd like to read more of a timeline about these two - have a look at a very detailed analysis prepared by Cedric Moro (@Moro_Cedric).

This case study also confirms that at least some of the EVD cases will not ever be getting a laboratory confirmation as I wondered about in my Ebola virus sampling issues post 09-Apr. Not only do EVD case numbers change, occasionally in slippery ways, but there are also occasions when they won't ever change despite us wanting them too. If I was a pedant this could drive me to insane.