You’ve probably heard it. There’s an ongoing Ebola virus epidemic in West Africa, which so far has claimed over 4,000 lives. While various news sites have been going into overdrive with the press coverage, both with extensive, pernicious coverage and speculation on the potential threat to the Western world, and the gargantuan task faced by healthcare workers in West Africa.

Much discussion has been devoted to how dangerous Ebola virus really is. Both the WHO and CDC have made it abundantly clear that the Ebola virus does not pose a major health risk to developed nations with modern healthcare systems. But the threat to West Africa is very real, with the humanitarian NGO Medicine Sans Frontières declaring that unless an international effort is secured, the outbreak will worsen and expand for months to come.

Despite this, many people have tried to put the outbreak in context. In the last few days, this image has been making the rounds on social media:

AfricasKillers

As you can see, it purportedly shows the burden of Ebola is much smaller when compared to other diseases. This message has an important consequence, that many of the ‘big killers’ are curable or can be managed, unlike Ebola virus which, at present, has no cure and only experimental therapies exist. It is an appealing notion to the utilitarians who may wish to maximise their relief effort through donations to combat the more manageable, and deadlier, diseases.

Unfortunately the truth, as always, is in the data. The image above shows yearly deaths due to disease across the whole of Africa. Considering the Ebola virus outbreak is only seriously affecting three countries so far, Liberia, Sierra Leone and Guinea, this is hardly a fair comparison. So I’ve gone back to compare the disease burden of Ebola against the other ‘big killers in Africa’ in those three countries:

WestAfrica1

Malaria, TB and HIV are still significant problems, but Ebola is not the paltry, minor killer shown in the previous graph. Instead, it hovers at around half the number of deaths of those two diseases and equivalent to hunger. Now, ‘hunger’ is a difficult concept to categorise, and the WHO prefers deaths attributed to nutritional deficiency, so we have gone with that. Also note numbers for nutritional deficiency are somewhat out-dated, from 2008, and big progress has been made against infant malnutrition since then, particularly in Sierra Leone.

The numbers for Ebola are also conservative and ignore that the outbreak is currently ongoing and likely to lead to more deaths before the year is out. More impressively, we can also include the most common killer in all three countries, as categorised by the WHO:

WestAfrica2

Diarrhoea, particularly in children under the age of 1, is by far the greatest killer in these three West African nations. So the original image is an excellent example of cherry-picking your data, by excluding perinatal complications such as diarrhoea and collapsing data across the whole African continent, instead of the relevant countries for this outbreak.

It is difficult to compare the real, day-to-day impact of such diseases on the ground. Unlike malaria, TB or even HIV, the Ebola epidemic has had a devastating human, social and economic impact in West Africa. While other diseases may cause a greater number of deaths, and should be tackled as vigorously as Ebola, we must not obfuscate the point with bad graphics. The best kind of healthcare response is an informed one, and for that we need responsible, clear and objective data.

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Rates of Ebola virus infection and death in the current outbreak are being produced by the WHO and frequently updated on the relevant Wikipedia page. The WHO also keeps excellent public and readable statistics on health worldwide, including their 2012 report on the burden of disease showing country-by-country statistics.

For those looking a more in-depth look at the nuts and bolts of Ebola, transmission and mechanisms of infection, I highly recommend this episode of the podcast This Week In Virology.

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