	Generational Dynamics
	Forecasting America's Destiny ... and the World's

\| HOME \| WEB LOG \| COUNTRY WIKI \| COMMENT \| FORUM \| DOWNLOADS \| ABOUT \|

Generational Dynamics Web Log for 30-Oct-2014
30-Oct-14 World View -- World Health Organization says Ebola outbreak is 'in decline'

Web Log - October, 2014

30-Oct-14 World View -- World Health Organization says Ebola outbreak is 'in decline'

Unanswered questions about the spread of Ebola

This morning's key headlines from GenerationalDynamics.com

World Health Organization says Ebola outbreak is 'in decline'
Unanswered questions about the spread of Ebola
Comparing the Ebola location maps

World Health Organization says Ebola outbreak is 'in decline'

World Health Organization (WHO) assistant director Bruce Aylward said that "We're seeing a reversal of that rapid rate of increase to the point that there seems to be a decline right now."

He added, "Getting a slight decrease in the number of cases on a day-to-day basis, versus getting this thing closed out, is a completely different ball game." This is a highly ambiguous statement. It could mean that the total number of cases is declining, meaning the number of new cases is now smaller than the number of people who are recovering or dying. Or it could mean that the number of NEW cases has declined, which would mean that the number of new cases is no longer growing exponentially, but has leveled off.

Or it could mean that the number of new cases is still growing exponentially, but at a smaller exponential rate.

The figures that I derived from the WHO situation reports (see the next item, below) seems to indicate this latter interpretation. A couple of months ago I was hearing that the number of Ebola cases doubled every 3 weeks. The figures I derived indicate that the number doubles every 4.7 weeks which is exponential growth at a slower rate.

A couple of weeks ago I wrote "19-Oct-14 World View -- Forecasting the Ebola endgame and Global Risk". I identified several continuing risks about Ebola -- that there could easily be new outbreaks anywhere in the world in megacities, slums and war zones. None of that is changed by Aylward's statement, and I'm pretty sure that he wouldn't disagree with me. Reuters

Unanswered questions about the spread of Ebola

There has been very little Ebola spread out of the three countries in West Africa. This has led me to wonder if perhaps I was missing something.

The World Health Organization publishes Ebola Situation Reports every few days.

I went to the most recent situation report (PDF), dated October 25, 2014. The following table depicts the total numbers of infections and deaths:

+---------------+--------------+--------- +
| Country       | # infections | # deaths |
+---------------+--------------+--------- +
| Guinea        | 1553         | 926	  |
| Liberia       | 4665         | 2705	  |
| Sierra Leone  | 3896         | 1281	  |
| Mali          | 1            | 1	  |
| Nigeria       | 20           | 8	  |
| Senegal       | 1            | 0 	  |
| Spain         | 1            | 0	  |
| U.S.          | 4            | 1	  |
+---------------+--------------+--------- +
| Total         | 10141        | 4922	  |
+---------------+--------------+--------- +

IT seems strange that the only large numbers of cases are in the original countries (Guinea, Liberia, Sierra Leone), and that the only cases outside of Africa were in Spain and U.S. It doesn't make sense to me that Ebola hasn't spread to other countries in Africa, and that there haven't been individual cases in other countries in Europe or Asia or Latin America.

Comparing the Ebola location maps

So, in order to do further analysis, I went back to WHO's original situation report (PDF), dated August 29, 2014, and I compared some of the numbers in the two reports, in order to get an estimate of the growth rate in the number of cases.

If you take the total number of infections -- 3052 on August 29, and 10141 on October 25 -- and do a computation, then you get that the number of infections doubles every 4.7 weeks, which is a little more than a month (4.25 weeks per month).

If you apply this rate to the number of infections, you get 40K by Jan 1, 80K by Feb 1, 160K by Mar 1, and so forth. But can that doubling rate be sustained? The WHO announcement that the outbreak is "in decline" would seem to indicate that it can't be sustained.

So next, I extracted the Ebola location maps from the two reports.

Here's the August 29, 2014, map:

Ebola location map, 29-Aug-2014 (WHO)

Ebola location map, 29-Aug-2014 (WHO)

Here's the October 25, 2014, map:

Ebola location map, 25-Oct-2014 (WHO)

Ebola location map, 25-Oct-2014 (WHO)

Comparing these two maps, you can see that most infections were in the west, but they've apparently been moving eastward, apparently stopping at the borders of Mali and Côte d'Ivoire. This is not credible. These country borders are porous, and tribal boundaries do not correspond to national boundaries. It's not credible that the spread of Ebola has stopped dead at these country borders.

We recently had the news story of the two year old infected baby who was carried on a bus all the way from Liberia to the western border of Mali almost to the eastern border, with multiple stops, including a two-hour stop in Bamako. Other than the death of the 2 yo, we haven't heard anything more about Ebola in Mali. ( "25-Oct-14 World View -- Two-year-old baby in Mali dies after spreading Ebola")

At least a few cases of Ebola must surely have spread into these Mali and Côte d'Ivoire, on the border with Liberia, without our being aware of it. If this is true -- and I don't see how it could not be true -- then there must be unreported cases in these countries.

If there are individual cases in the U.S. and Spain, then there must be unreported individual cases in other countries. Consider the following:

Cuba has sent hundreds of medical professionals to West Africa.
China has thousands of workers in the region.

If there have been Ebola cases in the U.S. and Spain, it's hard to believe that Cuba and China would be immune to Ebola cases. What's different about Cuba and China is that if either has an outbreak of Ebola in either country, it would be covered up and we'd never know, until the outbreak became extremely serious. (This is what happened in China with the SARS outbreak ten years ago.)

There are plenty of people, including migrant workers, who go back and forth between Africa and their home countries, including Asia and Latin America. Some countries are so undeveloped that officials might not even know there's an Ebola outbreak until it had spread for several days.

So there are a lot of unanswered questions about what's going on. There must be or will be many unreported cases of Ebola, in West Africa and elsewhere; it's not credible to believe otherwise.

Finally, returning to the question of whether the Ebola outbreak is "in decline," one possibility is that it's really in decline, and another possibility is that the only thing that's declining is the number of reported cases, with sharp increases in the number of unreported cases. We should have definite answers by the end of the year. WHO Ebola Situation Reports

(Comments: For reader comments, questions and discussion, see the 30-Oct-14 World View -- World Health Organization says Ebola outbreak is 'in decline' thread of the Generational Dynamics forum. Comments may be posted anonymously.) (30-Oct-2014) Permanent Link
Receive daily World View columns by e-mail
Donate to Generational Dynamics via PayPal

Web Log Pages

Current Web Log

Generational Dynamics Web Log for 30-Oct-2014 30-Oct-14 World View -- World Health Organization says Ebola outbreak is 'in decline'

World Health Organization says Ebola outbreak is 'in decline'

Unanswered questions about the spread of Ebola

Comparing the Ebola location maps

Web Log Pages

Generational Dynamics Web Log for 30-Oct-2014
30-Oct-14 World View -- World Health Organization says Ebola outbreak is 'in decline'