Sunday, September 7, 2014

Ebola: How Many Will Die?

It's a crude question, one that turns an international tragedy into a football score. Part of the fascination that Ebola holds for people is the death toll, and news outlets love to tally the stats as we see the bodies accumulate, though from our safe spectator perch in the US.

So I'm not precisely thrilled to frame this entry by focusing primarily on raw numbers, but there's a reason for it if you'll bear with me for a few grafs. It arises from a comment in this recent Salon post by Andrew Leonard. Leonard refers to the WHO estimates that the outbreak may infect as many as 20,000 people, resulting in a death toll of perhaps half that, and then quotes an infectious disease physician who thinks that the WHO's estimate is low "by an order of magnitude."

I was that doctor, and at the moment I'm still standing by my general assertion that 20,000 cases is a dramatic underestimate. Here's some very basic reasoning:

One: disease surveillance in Sierra Leone and Liberia, the two hardest-hit countries, is minimal in some small areas and non-existent everywhere else. The population of these two nations is about ten million people, and that number appears to be reasonably accurate based on 2008 Liberian census data published by the UN. But the report hides a telling fact: that such a census basically wasn't possible without substantial outside help from the international community. After the census ended, those people left, and Liberia was left to its own devices for surveillance. In other words, Liberia doesn't have much internal monitoring resources, for population, or disease, or any other kind of demographic information. Tracking sick people of any kind is beyond their capacity at the moment, and it is only marginally better in Sierra Leone. The international effort is coming, but coming slowly out of an appropriate abundance of precaution that the aid groups are taking to ensure the safety of their staff.

Two: so when we see these numbers of Ebola cases, we're really only seeing the cases that are coming to attention, and we know that there are more cases out there. Many locals are terrified that Ebola treatment facilities are just death mills or worse, are probably keeping their loved ones at home, "hiding" them from official eyes. This has caused Sierra Leone to take the unprecedented step of placing the entire country under quarantine so that officials may conduct a house-to-house search for three days in an attempt to dig a trench to stop the fire from spreading. (MSF, more commonly called "Doctors Without Borders" in the US, heaps skepticism on this plan here.)

Three. when patients are coming to attention, they are trying to mask their symptoms. This is probably how Rick Sacra, the latest American doctor to become infected, contracted the virus. Sacra was not working with Ebola patients, but was rather providing care in an obstetric ward. He was--one hopes--careful enough to check his patients' temperatures before administering care. But anyone can make a fever go away for a few hours with some Tylenol, although they are no less infectious during this period.

Four. combine these three factors and witness a lethal virus on the loose in a densely packed neighborhood like West Point in Monrovia, which has a population of 50,000--or maybe 75,000, or maybe 100,000 depending on your source--and one can only currently guess at the results. Just by sheer concentration, the outbreak has the potential to flourish into the thousands in West Point alone. West Point was cordoned off during the last week of August, and the level of paranoia and misunderstanding there is profound, to the point that locals attacked an Ebola quarantine center, taking away infected patients as well as bed linens and other material covered in the body fluids of probable patients. This single act almost certainly consigned dozens, perhaps hundreds, perhaps thousands, to death in West Point.

Five. people are doing everything they can to flee outbreak areas, and while many of these people may not be infected, all it takes is one infected person to bring disease to an entirely new place. The Nigerian government did a remarkable job containing the outbreak after Liberian Patrick Sawyer brought Ebola to that country in his own effort to outrun the virus. (Sawyer, the article notes, was trying to fly to the United States for treatment, having a ticket that would bear him to Minnesota. Surely that would have grabbed Americans' attention in an entirely different way, and I'm somewhat amazed that this wasn't really broadcast by the US media.) They thought that they had contained it, only to discover that one of their own medical personnel had carried the outbreak from Lagos to Port Harcourt as he fled the government-imposed quarantine.

When viewed on a region-wide scale, these factors suggest to me that we're not even close to some semblance of control over this situation. More than 20 million people live in the three most severely afflicted countries of Guinea, Sierra Leone, and Liberia, and there's no evidence that the outbreak is even slowing down. So I simply don't understand where the 20,000 figure came from, and I wouldn't be surprised that we've already passed that number as I write this. Indeed, at least one academic adept at statistics notes a best case scenario that is not quite double the WHO estimate, with a "medium" estimate close to my casual remark that WHO has underestimated by an order of magnitude, and a "nightmare" scenario that I'm too terrified to repeat--look for yourself.

So why obsess about numbers? Because we're possibly looking at the societal collapse of a good-sized chunk of West Africa unless we appreciate the scale of this disaster. Comparing this to, say, the Haiti earthquake may be too generous. Think more like Rwanda in the early 90s or Cambodia in the 70s: a complete disintegration of anything resembling order, replaced by fear, distrust, and quite likely violence. At the moment, I still think there's a chance to contain this and avoid this kind of total breakdown. But the window is closing, and I'm not yet sensing the level of alarm in government responses that will be required to stop it.


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