Thinking About Ebola

At this stage in what may be a series of events of worldwide importance, I think it’s appropriate to consider a few alternative scenarios dispassionately. Before I begin it might be helpful to define a few terms: epidemic, endemic, and pandemic. If you know Greek, their meanings are obvious but classical educations have become rare.

We characterize a disease as “epidemic”, literally “among the people”, when there is a outbreak of an infectious disease in a large number of people over a short period of time. A disease is “endemic”, literally “in the people”, when it is maintained within a population at a more or less stable rate permanently. For example, chickenpox is endemic in the United States. A disease is said to be “pandemic”, literally “all of the people”, when there is global outbreak of a disease affecting a significant number of people.

Here are some scenarios I think are worth thinking about:

• Worldwide Ebola pandemic
• Ebola becomes endemic outside Africa
• Ebola becomes endemic in sub-Saharan Africa
• Ebola becomes endemic in West Africa
• Ebola epidemic outside West Africa
• Ebola epidemic in West Africa
• Ebola outbreak outside West Africa

There are other possibilities that could be considered but that list hits the high spots. Now let’s put a little flesh on these scenarios and do a bit of speculating about their likelihoods.

Worldwide Ebola pandemic

I think this is extremely unlikely. I have no way of calculating the costs of this taking place but they would be vast. Half of the world’s population would die.

Ebola becomes endemic outside Africa

I think this is unlikely.

Ebola becomes endemic in sub-Saharan Africa

I think this is somewhat unlikely. If it takes place it will be a consequence of inaction in stemming the epidemic in West Africa, the weak economies and institutions in sub-Saharan Africa, and indifference on the part of the developed world. The costs of this scenario both in human and economic terms would be large.

Ebola becomes endemic in West Africa

This is a substantial and significant fear and the longer the epidemic in West Africa continues the more likely it becoming endemic will become. I think this is slightly likely.

Ebola epidemic outside West Africa

I think this is somewhat unlikely. If it does take place, it will be a consequence of allowing the epidemic in West Africa to continue and is most likely to take place in countries with weak economies and institutions.

Ebola epidemic in West Africa

Since there is already an ongoing epidemic in Guinea, Liberia, and Sierra Leone, this is now a certainty.

Ebola outbreak outside West Africa

Sadly, since there are has already been a small outbreak in the United States, this, too, is now a certainty. It should debunk the notion that an outbreak in the United States is impossible but interested parties are already trying to spin the truth away, a practice that I think increases the likelihood of future outbreaks rather than reducing their likelihood. IMO the outbreak was caused by reckless behavior on the part of professionals. We can only hope that the professionals will be chastened by the experience but I see no signs of that yet.

Note that these scenarios operate along several different planes, i.e. geographic extent, duration, number of cases, and cost. Also note that as the last-mentioned scenarios increase in likelihood the scenarios mentioned earlier become more likely, too. So, for example, if Ebola becomes endemic in West Africa, it will become harder (and more expensive) to prevent it from becoming endemic in sub-Saharan Africa more generally.

That’s why I think that we need to undertake a somewhat more muscular effort in Guinea, Liberia, and Sierra Leone that we presently have. As of this writing we have fewer than 1,000 troops there and they are insufficiently trained to deal with Ebola cases themselves.

They are better prepared to build hospitals but hospitals won’t staff and equip themselves. Not only the United States but France, the United Kingdom, Germany, and China should be making significant commitments of money, materiel, and people in West Africa.

The United States Navy has two hospital ships capable of treating 1,000 patients each and eight Wasp class amphibious assault vehicles capable of treating 600 patients each. These are, in effect, large mobile modern hospitals, fully staffed and equipt. Should some of these existing resources be deployed there? That’s a question. I’m not in the Navy and I don’t know the complications or issues involved.