Ebola transmission rate in current outbreak, similar to previous outbreaks..

If there is any positive news in the West African ebola outbreak it is that an analysis of transmission rates are consistent with those of previous outbreaks in central Africa. The reason that this is not bad news is that given the 350-400 mutations of abola virus found in the current epidemic, the same routes of transmission are likely the only ones occurring.

Meanwhile, in the DRC......

the WHO reports a doubling of the case number to 62, with a current case fatality rate(CFR) of 58%. Of course, it is not known just how many of those infected are still in danger of being added to the CFR.

If you read the first linked to article, you will not that the individual transmission rate climbed from 1.4 to 1.7 in a month. That may not sound like a huge difference, but over time the numbers continually diverge. Do the simple math over say 20 generations of infection. The small difference in the starting condition leads to a huge difference in outcomes. Additionally, since the infection rate ramped up dramatically in but one month, it is unlikely to stay at the same rate. The current infection rate may be higher or lower. The simple month long growth in infection rate is--at least on the surface--very troubling.

I did a straight line analysis of the two transmission rates to 19 generations after patient zero. Here are the results for a 1.4 transmission rate:

1 2nd 1.4 3rd 1.96 4th 2.77 5th 3.84 6th 5.38 7th 7.53 8th 10.55 9th 14.77 10th 20.68 11th 29.0 12th 40.6 13th 56.84 14th 79.5 15th 111.3 16th 155.8 17th 218.1 18th 305.3 19th 427.5 20th 598.5

And for a 1.7 transmission rate:

1 2nd 1.7 3rd 2.9 4th 8.4 5th 14.3 6th 24.31 7th 41.3 8th 119.4 9th 195.5 10th 332.35 11th 565 12th 960.5 13th 1632.9 14th 2776 15th 4719 16th 8022 17th 13637 18th 23183 19th 39411 20th 67000

That is quite sobering. Oh, the math isn't perfect as I rounded some figures lest I get lots of noise on the right side of the decimal point.

This simple math applies to interest rates as well. That's all it really is. Of course epidemics do not progress like this forever. I just wanted to illustrate the very basic data as pointed to in this article.

I am just a lay lackey. My little exercise does point to a potentially very bad outcome should the infection rate continue to progress at the higher rate.