Twenty-one days: the maximum incubation period for Ebola Virus Disease. That means if you have come into contact with the virus but have no symptoms by day twenty two, then you are clear.

Forty two days: the incubation period x 2, and the period it takes for a country to be officially considered clear of the disease. If no new suspected cases are reported for 42 days, the outbreak is over.

Today, Wednesday 13th August 2014, is a big day for me ... it has been twenty-one days since I left Liberia, and for the first time I know beyond a doubt that I am Ebola-free. Not everyone is so lucky. In my first 14 days of incubation in the comfort of my Southampton home, the number of cases in Liberia more than doubled from 249 on 23rd July to 554 on 6th August. Of these cases, 294 people had died. The country is in a state of emergency, schools are closed, roads are blocked, communities are quarantined and attempts to bring the disease under control are being crippled by widespread fear.

So for another 21 days I am going to write a blog post every day to raise awareness of the grim challenge confronting Liberians, and to raise funds to support the Red Cross, who I work with collaboratively in my normal life as a PhD social researcher, and who are at the front line fighting the worst known Ebola outbreak in history.

Saturday 23 August 2014

Tracking the spread

It’s day 11, and this post marks the half-way point through my 21 days of blogging about Ebola, so I decided it’s time for a review of the situation in countries that are affected – and at the same time to clarify definitions that are used to talk about cases.

The figures that we hear reported about the number of cases of Ebola include suspected, probable and confirmed cases.  But what is the difference between these?  Well, following the WHO’s guidelines, a suspected case could be any one of the four following scenarios:

(1) Someone who suffers from a sudden high fever and has had contact with a suspected, probable or confirmed case of Ebola, or with a dead or sick animal.

(2) Someone with sudden onset of high fever who has at least three of Ebola’s symptoms:
  • Headaches
  • Vomiting
  • Loss of appetite
  • Diarrhoea
  • Lethargy
  • Stomach pain
  • Aching muscles or joints
  • Difficulty swallowing
  • Breathing difficulties
  • Hiccups

(3) Someone with inexplicable bleeding.

(4) Someone who dies suddenly and inexplicably.

A probable case is a suspected case that has been evaluated by a clinician, OR who has died and had contact with a confirmed Ebola sufferer.

A confirmed case means that laboratory tests have confirmed that the disease really is Ebola.

The thing is, Ebola in its early stages looks a lot like other common diseases in sub-Saharan Africa – particularly Malaria and Typhoid - and there is not always a clinician or a laboratory to hand to examine the case.  When you look at data about Ebola it’s important to understand that it includes these three categories of cases, as otherwise it seems peculiar that sometimes the number of cases seems to go down ever so slightly, rather than up.  The reason for this is that, following laboratory testing, occasionally cases are reclassified.

The graph below tracks the number of (suspected, probable and confirmed) cases of Ebola between 10th June and the WHO’s most recent report, released yesterday, which includes figures up to 20th August.



The outbreak began in Guinea, and although the number of cases appears to be climbing in all countries, the rate of transmission is highest in Sierra Leone and Liberia.  If you look just at the two week period up to 20th August, during this time the number of cases in Nigeria rose from 13 to 16 – that is an increase of 23%.  The number of cases in Guinea also increased by 23%, from 495 to 607 cases.  The number of cases in Sierra Leone jumped from 717 to 910, an increase of 27%.  In Liberia, where transmission is most out of control, the number of cases rocketed from 554 to 1082 – that is an increase of 95% in a fortnight.


Perhaps that is why the President of Médecins Sans Frontières (MSF) commented in a statement just over a week ago that the regional international effort needs to pay particular attention to Liberia if we are to stop the spread of Ebola.

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