By many measures, the Corona virus sweeping through the world today is considerably less deadly to individual humans than the Ebola virus that swept through the Mano River Union countries of West Africa six years ago. The Case Fatality Rate, CFR, of Corona has been variously estimated at anywhere from 0.5% to 2 or 3% in the population as a whole, with elderly patients having higher mortality and young patients lower. The CFR of Ebola, in the early stages of the West African epidemic was well over 50%, and over the entire epidemic the CFR was calculated at about 40% .  All these figures should be taken with a small pinch of salt, as it can be quite difficult to determine the true CFR, probably more so for Corona than for Ebola. Also, and naturally, the CFR of disease depends on what treatment, if any, is applied to the disease. Thus CFR of Ebola treated in hospital might be very different from that of untreated Ebola. And CFR of Ebola treated in Western hospitals MIGHT be different from that of Ebola treated in Sierra Leonean hospitals. More on the extreme importance of estimating the CFR below.


So if it is relatively benign, at least compared to Ebola, exactly how has Corona managed to bring the entire world economy crashing to its knees in a few short weeks? How has it wreaked this havoc? After all, Ebola travelled all over the world, to the rest of West Africa, to Europe and America, and was relatively easily stamped out wherever it went. Corona  apparently and somewhat counterintuitively, by its relative mildness, is able to more easily work its way into the human population and cause greater overall damage even though it is less deadly to any one individual.  It is less visible, it inspires less fear, and so it moves around with greater ease. The majority of those infected apparently show no, or only mild, symptoms. They move around spreading infection, unsuspected and unsuspecting. To the best of our knowledge, Ebola, with its attendant vomiting and bleeding and diarrhoea, never came close to the lowliest President. In this short period though, the world has learnt that Corona has come quite close to a good number of world leaders including Brazilian President Bolsonaro, UK Prime Minister Boris Johnson (today tested positive), and US President Donald Trump. In a very short period of time Corona has demonstrated its ability to reach the high and mighty. The world has responded with lockdowns, mass quarantining, travel restrictions and school closures. Interestingly much of this is precisely the response that the WHO and other experts told us NOT to impose during Ebola. It is the first reaction of frightened people and governments all over the world, but it MAY be justified by Corona's devilish sneakiness.

What if Corona lasts a year?  Ebola lasted almost two. Can the world afford to shut down for a year? Or two? Many of West Africa's poor can not afford a shut down of even a day. The US and other Western administrations are putting together financial assistance programs for their citizens worth hundreds of billions of dollars, to support them during a period of enforced layoffs. These kinds of programs are clearly beyond the reach of African governments. During Ebola people for the most part went to work. There were one or two nation wide lockdowns, but as the epidemic dragged on more and more people advised themselves that in a choice between starvation and the risk of Ebola, it was wiser to accept that risk. However, this is a different virus, and the risks are different.

So how did we defeat Ebola, especially after the virus had scattered widely around the three Mano River Union countries? The WHO, MSF, which was a key player, and other experts, consistently advocated targetted measures and public education as opposed to mass restrictions. It's safe to say that surveillance, contact tracing and targetted quarantining were key factors in the ultimate victory. Targetted measures are generally far cheaper than nation-wide restrictions and thus can be maintained far longer, even indefinitely, from a financial point of view. Also from a national psychological point of view. Of the billions of dollars the West is contemplating to support its citizens, just one billion dollars would buy a great deal of surveillance and contact tracing, even at Western labour rates. In 2015 we spent a considerable amount of time trying to figure out how Liberia so dramatically turned around its Ebola position, which at one point was truly desperate even viewed from Sierra Leone, and emerged Ebola-free many months before its neighbours. The only explanation we could find was greatly increased contact tracing.

Now it may be that by Corona's very nature, its relative mildness and consequent rapid spread, surveillance and contact tracing are less effective than they were with Ebola. In which case the pendulum swings more towards the mass lockdowns that are currently the favoured strategy. This is a different virus; the strategies that worked against Ebola MAY not be the best strategies to fight Corona, but it's worthwhile reminding ourselves what those strategies were.

The Case Fatality Rate, CFR During Ebola I wrote several articles on the extreme importance of the Case Fatality Rate. In a thought-provoking article on Corona case fatality, John Ioannidis points out that tens of thousands die from influenza annually in the US. This is accepted as routine, with little comment. In West Africa and Africa, many thousands die from malaria every year. We try to reduce the number, but the fact is this continues to happen every year and we accept it. So, cold and hard as it may seem, we do accept a certain number of deaths a year from disease. The core issue then with Corona is how many are going to die. These are additional deaths, and every additional death is one too many, but still, IF we are going to lose one thousand from Corona and fifty thousand from malaria, then malaria remains by far the greater problem. IF malaria is by far the greater problem then substantially more of our scarce health resources should be directed towards the problems of malaria.

As Ioannidis makes clear in his article, determining the true CFR of Corona at this point is problematic. This is where the reactions of governments around the world can appear panicky. It appears that a large and undetermined number of people have been infected with the virus without falling ill or showing serious symptoms. To get an accurate picture of the situation this number needs to be determined. But, but, BUT the mortality figures coming out of Italy and Spain give great pause for thought. 500, 600, 800 dead from "corona-related illnesses" in one day. How can this be? When the dust settles, what will this mean for the CFR? How many cases in Italy thus far, how many deaths?  3,405 deaths from 41,000 cases (March 19).  OK this gives a provisional CFR of 8.3%. (March 27, 80,589 cases, 8,215 deaths, CFR = 10.2%)  "Provisional" because the outbreak is ongoing, perhaps not even yet at its peak. Many of those infected cases may not survive, which would mean the calculated CFR would actually increase after all the cases resolve. What's the overall CFR for all countries? The World Health Organisation gives 8,700 deaths from 209,000 cases (March 19) .  This gives a CFR of 4.2% including the reportedly resolved situation in Woobay, where the pandemic is said to have begun (March 27, 465,915 cases, 21,031 deaths, CFR = 4.5%). In Woobay where it all began and which is at a later stage of progression, how many cases, how many deaths? 3,248 deaths from 80,967 cases (March 20). This gives a CFR of 4.0%.  In the USA 82,100 cases, 1,195 deaths (March 27) gives a CFR of 1.5%. Why the huge differences in CFR? And - the key question - how many had mild or no symptoms of Corona, did not report to the authorities and thus were not counted in the total cases. No one knows for sure. And this number would move the CFR down. Each one percent downward movement in CFR indicates a "saving" of tens, hundreds of thousands of lives.