How many people have caught Ebola – and how many have died?
There has never been an Ebola outbreak on the scale of the current one; more than three times as many people are known to have died in this outbreak as died in all previous outbreaks put together.
Going by the raw numbers, it would appear that the "case fatality rate" – that is, the percentage of people who die after contracting the disease – is lower than in many previous outbreaks. At just under 50%, it would suggest that a bigger proportion of patients have survived Ebola than in all but three other outbreaks.
However, even that marginally hopeful sign may be optimistic. The chart above is based on current World Health Organisation figures, which the WHO openly says will underestimate the real figures by a significant amount due to the difficulty in tracking cases in regions where the health infrastructure has been overwhelmed. A study published in the New England Journal of Medicine found a case fatality rate of 70.8% up to 14 September when looking at only cases with "definitive recorded clinical outcomes".
The real figure for the number of cases and deaths in the epidemic to date could be twice as large as the figures shown above.
There has never been an Ebola outbreak on the scale of the current one; more than three times as many people are known to have died in this outbreak as died in all previous outbreaks put together.
Going by the raw numbers, it would appear that the "case fatality rate" – that is, the percentage of people who die after contracting the disease – is lower than in many previous outbreaks. At just under 50%, it would suggest that a bigger proportion of patients have survived Ebola than in all but three other outbreaks.
However, even that marginally hopeful sign may be optimistic. The chart above is based on current World Health Organisation figures, which the WHO openly says will underestimate the real figures by a significant amount due to the difficulty in tracking cases in regions where the health infrastructure has been overwhelmed. A study published in the New England Journal of Medicine found a case fatality rate of 70.8% up to 14 September when looking at only cases with "definitive recorded clinical outcomes".
The real figure for the number of cases and deaths in the epidemic to date could be twice as large as the figures shown above.
There has never been an Ebola outbreak on the scale of the current one; more than three times as many people are known to have died in this outbreak as died in all previous outbreaks put together.
Going by the raw numbers, it would appear that the "case fatality rate" – that is, the percentage of people who die after contracting the disease – is lower than in many previous outbreaks. At just under 50%, it would suggest that a bigger proportion of patients have survived Ebola than in all but three other outbreaks.
However, even that marginally hopeful sign may be optimistic. The chart above is based on current World Health Organisation figures, which the WHO openly says will underestimate the real figures by a significant amount due to the difficulty in tracking cases in regions where the health infrastructure has been overwhelmed. A study published in the New England Journal of Medicine found a case fatality rate of 70.8% up to 14 September when looking at only cases with "definitive recorded clinical outcomes".
The real figure for the number of cases and deaths in the epidemic to date could be twice as large as the figures shown above.
How bad could it get?
How badly has Ebola hit healthcare workers?
One reason Ebola is such a worrying disease is that, transmitted as it is by bodily fluids and close contact with the sick, it tends to hit healthcare workers especially hard. In the current outbreak, according to the most recent available figures for healthcare worker cases, almost 5% of those who have contracted Ebola have been healthcare workers. This is both cruel – killing those who tried to help others – and potentially very damaging to efforts to contain the epidemic.
However, it could be even worse: In the SARS outbreak of 2003, over 21% of those infected (1,706 out of 8,096) were healthcare workers.
One reason Ebola is such a worrying disease is that, transmitted as it is by bodily fluids and close contact with the sick, it tends to hit healthcare workers especially hard. In the current outbreak, according to the most recent available figures for healthcare worker cases, almost 5% of those who have contracted Ebola have been healthcare workers. This is both cruel – killing those who tried to help others – and potentially very damaging to efforts to contain the epidemic.
However, it could be even worse: In the SARS outbreak of 2003, over 21% of those infected (1,706 out of 8,096) were healthcare workers.
One reason Ebola is such a worrying disease is that, transmitted as it is by bodily fluids and close contact with the sick, it tends to hit healthcare workers especially hard. In the current outbreak, according to the most recent available figures for healthcare worker cases, almost 5% of those who have contracted Ebola have been healthcare workers. This is both cruel – killing those who tried to help others – and potentially very damaging to efforts to contain the epidemic.
However, it could be even worse: In the SARS outbreak of 2003, over 21% of those infected (1,706 out of 8,096) were healthcare workers.
Is Ebola the biggest killer in Africa?
As critical as the situation in Guinea, Liberia and Sierra Leone is, Ebola is still not the biggest killer in the area – yet. In just those three countries alone, diseases such as malaria, HIV/AIDS, tuberculosis, and meningitis caused more deaths in 2012 (the most recent year for which we have figures) than Ebola is known to have caused in the outbreak to date. More deaths also result from babies dying at birth and malnutrition.
Obviously, this will change if the epidemic continues, or the current figures are revised upwards due to underreporting.
When you look at Africa as a whole, HIV is by far the biggest killer – and the effect of Ebola so far is dwarfed by many of the continent's biggest causes of death (plus many others not shown on the chart above, such as respiratory infections and diarrhoeal diseases). Crucially, unlike Ebola, several of these mass-scale killers are already preventable or curable.
As critical as the situation in Guinea, Liberia and Sierra Leone is, Ebola is still not the biggest killer in the area – yet. In just those three countries alone, diseases such as malaria, HIV/AIDS, tuberculosis, and meningitis caused more deaths in 2012 (the most recent year for which we have figures) than Ebola is known to have caused in the outbreak to date. More deaths also result from babies dying at birth and malnutrition.
Obviously, this will change if the epidemic continues, or the current figures are revised upwards due to underreporting.
When you look at Africa as a whole, HIV is by far the biggest killer – and the effect of Ebola so far is dwarfed by many of the continent's biggest causes of death (plus many others not shown on the chart above, such as respiratory infections and diarrhoeal diseases). Crucially, unlike Ebola, several of these mass-scale killers are already preventable or curable.
As critical as the situation in Guinea, Liberia and Sierra Leone is, Ebola is still not the biggest killer in the area – yet. In just those three countries alone, diseases such as malaria, HIV/AIDS, tuberculosis, and meningitis caused more deaths in 2012 (the most recent year for which we have figures) than Ebola is known to have caused in the outbreak to date. More deaths also result from babies dying at birth and malnutrition.
Obviously, this will change if the epidemic continues, or the current figures are revised upwards due to underreporting.
When you look at Africa as a whole, HIV is by far the biggest killer – and the effect of Ebola so far is dwarfed by many of the continent's biggest causes of death (plus many others not shown on the chart above, such as respiratory infections and diarrhoeal diseases). Crucially, unlike Ebola, several of these mass-scale killers are already preventable or curable.
Is Ebola as contagious as people say?
Should the US be panicking over Ebola?
Let's put it this way: There are places much worse off than America. Not only is it isolated by an ocean from the source of the outbreak, meaning only a handful of cases have appeared there so far, but it has medical infrastructure that is overwhelmingly better equipped to deal with cases that do arrive than the worst affected countries. To take just two measures of healthcare infrastructure quality, the US has the highest per-capita spending on health of any country in the world (even after you adjust for things being more expensive in the US), and it has almost 25 times as many physicians per person than even the best equipped country at the centre of the outbreak.
A major reason Ebola has spread so virulently through Guinea, Liberia, and Sierra Leone is that those countries' already-rickety medical systems have been overwhelmed. That is incredibly unlikely to happen in any wealthy Western country.
Let's put it this way: There are places much worse off than America. Not only is it isolated by an ocean from the source of the outbreak, meaning only a handful of cases have appeared there so far, but it has medical infrastructure that is overwhelmingly better equipped to deal with cases that do arrive than the worst affected countries. To take just two measures of healthcare infrastructure quality, the US has the highest per-capita spending on health of any country in the world (even after you adjust for things being more expensive in the US), and it has almost 25 times as many physicians per person than even the best equipped country at the centre of the outbreak.
A major reason Ebola has spread so virulently through Guinea, Liberia, and Sierra Leone is that those countries' already-rickety medical systems have been overwhelmed. That is incredibly unlikely to happen in any wealthy Western country.
Let's put it this way: There are places much worse off than America. Not only is it isolated by an ocean from the source of the outbreak, meaning only a handful of cases have appeared there so far, but it has medical infrastructure that is overwhelmingly better equipped to deal with cases that do arrive than the worst affected countries. To take just two measures of healthcare infrastructure quality, the US has the highest per-capita spending on health of any country in the world (even after you adjust for things being more expensive in the US), and it has almost 25 times as many physicians per person than even the best equipped country at the centre of the outbreak.
A major reason Ebola has spread so virulently through Guinea, Liberia, and Sierra Leone is that those countries' already-rickety medical systems have been overwhelmed. That is incredibly unlikely to happen in any wealthy Western country.
The data sets used in this post are available here, with sources.
docs.google.com
This post will be updated periodically as the figures for the Ebola outbreak change. Last update: 27 October 2014.