Uganda will likely release their 2014 Census results tomorrow.
The last census in 2002 had a population of 24.5 million.
This year, the count should come in at ca. 34-38 million.
A growth rate of 3-4% annually ...
Relative population growth rates in some parts of Africa are actually not decreasing, but increasing - not to mention absolute growth numbers.
There is absolutely no reason to think Africa is the exception to the demographic transition.
Fertility rates are declining in Africa along with death rates. Id be more concerned about the middle east as far as population growth is concerned. Oil has afforded them a major youth bulge that will still be alive when the oil runs out there.
I'm not saying that Africa is the exception to the demographic transition, it's just happening way too slowly (the fertility rates are going down only very slowly), which means absolute population growth is still raging on at a much higher speed due to the greater and greater base population.
Also, there are some countries like Niger, Mali, Chad, Uganda etc. where fertility rates have barely changed at all in the past decades or even risen (Niger). Mostly because of patriarchal structures, polygamy and of course poverty and a lack of education + fanatic US evangelicals. It looks like not a lot can be done here. And they are already living in a region (Sahel) that is slowly turning into a desert. Niger for example is projected to have a population of 100 Mio. by 2050, up from 17 Mio. now, so that's going to be a massive (food) problem + migration streams (to where eventually ? Europe). But family planning is a no-go for most of the people there, especially the ignorant men.
The Middle-East is the same ticking time bomb.