11 Sep 2014

The terrifying mathematics of Ebola

Ebola treatment facilities in Monrovia, the Liberian capital, are now so overwhelmed they are turning away up to 30 infected people every day according the medical charity Medecins sans Frontieres.

Given the rate at which the virus is spreading, it says the virus will soon be having an “apocalyptic” impact on the country and its neighbours unless there is a dramatic increase in international assistance.

“It could get very bad indeed,” said Prof John Edmunds, an epidemiologist at the London School of Hygiene and Tropical Medicine. “And I mean you can’t rule out some sort of nightmare doomsday scenario.”

“But the quicker we react and put interventions in place, the better chance we’ve got of avoiding something really, really serious.”

The leading epidemiologist is studying the spread of the virus in Monrovia, where the outbreak is now most intense. He has told Channel 4 News that based on the current rate of spread and lack of power to control it, it has the potential to infect the majority of the population of the country.

Getting a real handle on how fast the virus us spreading is becoming impossible. Official statistics are largely based on admissions and deaths in Ebola treatment facilities, from which people are now being turned away.

But based on data from recent weeks, researchers estimate each case in the community could be giving rise to about 1.5 more cases. “That means each case that is turned away generates more than one new case,” said Edmunds. And then you’re looking at an ongoing epidemic that could permeate right through society unless we do something to stop it right now.”

“The doubling time of this epidemic is about two weeks, so if we are overwhelmed with our resources right now, it’s going to be twice as bad in two weeks’ time.”

Last night the Bill and Melinda Gates Foundation pledged $50m to support the emergency response to Ebola. In recent days the US government has committed an additional $185m towards equipment and 100 medical personnel.

The British government also announced this week that it would build a 62-bed field hospital to help with the outbreak in Sierra Leone. The US says its commitment has added an additional 1,000 beds. However the World Health Organisation has estimated an additional 1,000 Ebola treatment beds are needed in Monrovia alone.

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7 reader comments

  1. neil says:

    Number of cases has been exponential since beginning of July ( roughly doubling every 2 weeks). WHO say their could be up to 20,000 cases. I cannot see why it would not go into the millions and spread to every shanty town in Africa.

  2. anon says:

    could your news team in Scotland ask our ‘leaders’ why they haven’t woken up to the seriousness of this situation and are not back in London, discussing with the relevant officials on how to send the large amount of extra help needed so urgently by these suffering people? This has to be done immediately. This is so shameful, is it going to be like the people on the mountain begging for help again, with journalists doing their best to highlight the suffering and our leaders doing nothing,
    until really pushed to do so? Is this leadership -no, is this caring? !!!!!!!! it is disgusting.

  3. Joe Grossman says:

    I fully support all comments calling for more assistance. I do not understand why the major powers have not flown-in more field hospitals and developed protocols to staff these facilities and supply the intravenous fluids needed as well as the barrier protections. Simply committing to giving money is not enough.
    The situation is shameful. Too little and maybe, even, too late.
    If one looks back at articles from June and even earlier, highly responsible persons were saying that the epidemic was “out of control.” Three months later, not even close to half as much as needs to be done has been accomplished.
    There were some statistics released today by WHO.
    In there Situation Report 3, it shows the total new cases reported in each of the past four weeks in the five countries with the major problem, Guinea, Liberia, Sierra Leone, Nigeria and Senegal.
    Epidemiological Week Ending – new cases, approximately, in one week
    May 18 10
    May 25 25
    June 25 100
    Aug 10 180
    Aug 17 400
    Aug 24 505
    Aug 31 490
    Sept 7 690
    [approximation from reading off of a graph of total cases reported]
    In the week ending September 7, we see about 290 more cases reported in one week as reported in the week ending three weeks prior. This is about a 70 percent increase [290 divided by 400] in three weeks, though it is not long enough to establish a trend.
    For example, the previous week showed about a 20 percent increase [90/400] in two weeks.
    However, if go back to four weeks previous, ending August 10, we see a 280 percent increase in new cases reported [510/180].
    If we go back 13 weeks, we see about 25 new cases, being reported. This means that about 26 TIMES as many were reported last week as three months ago.
    If go back to the middle of May, 2014, we see more than 50 times as many cases being reported now in one week.
    This is why headlines are screaming “exponential.”
    The meaning of some of the additional data WHO released today [Sept 12] is not as clear.
    Perhaps news reporters will decipher the meaning of the total cases and total deaths as reported in today’s situation report as compared with the previous situation reports.
    For those in the media who are studying the matter closely, you will be wondering about the deaths reported by WHO in their Situation Reports on September 5, 6 and 7th.

  4. will says:

    people talk about ebola like its not a big deal because, according to WHO, the # of affected is only in about 5000, compared to malaria, which infects millions. Moreover, apparently the disease has spread fairly slowly – taking many months to reach about 500 infections a week. WHO acknowledge their figures significantly underestimate the number of infected, but it issues them anyways.

    of course, even if WHO’s figures are somewhat accurate, the problem is just getting worse. I can’t understand why the UN and US is doing so little.

  5. Martin says:

    I have been following this for a number of months and have been amazed and appalled by the lack (of all) governments concern and action.
    The mainstream press seem to prefer to talk about bombing people rather than trying to save them.
    I’m beginning to think the press had been deliberately silenced in some quarters.
    I also believe that this would never have been allowed to fester if if had been white westerners suffering this way. This is doubly puzzling since the president of the United States is an Afro American.
    Because of inaction we are facing a near impossible task of controlling this deadly virus in Africa, and virus mutation is happening already.
    Wake up all those in positions of power, you may not have much longer to effect change.

  6. Will says:

    I too have been charting the outbreak based on the numbers the WHO is giving. I do this with a simple XL spread sheet chart and use the logarithmic axis. This makes it vary easy to measure and project the growth of ebola. I recommend you do this. I am not able to find any totals later that August 31. If you find a newer source, please advice.

    However, my chart shows the epidemic doubling every 4 weeks, not every two.

    I would also like to point out that the mortality rate of %54 is not correct. If new infections stopped tomorrow, those already infected will continue to die over the next month.

  7. Russ says:

    I don’t understand why every small country is not helping out. I also don’t understand why the people in west Africa are so ignorant about the disease and how to prevent its spread. I don’t think the disease is the fault of the US, but many west Africans think it is an American plot to experiment on them. Ignorance has its costs.

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