These statistics are very questionable. Certain diseases are counted as AIDS whether the HIV virus is present or not.
I would guess that a very substantial percentage, probably a majority, of these deaths are due to war, starvation, misgovernment, and the general decay of living conditions throughout most parts of Africa. Greedy politicians, socialist economic policies, and the spread of Islam don't help.
TB is a huge percentage of this #.
I agree that some of the numbers are dubious, claiming 40% of people in some countries seems a bit hard to believe credible. However even if the numbers are only 5%, the thing that must be kept in mind is that in Africa, most of sub sahara africa there is no treatment for HIV.. other than symptomatic treatement until they die... meaning once infected your life expectency is but a few years in most cases.
So if 1 in 20 has the disease, and they die every 2 years, it doesn't take a mathematician to figure out, your population is going to be decimated inside of a decade or two... imagine if every year 5% of american's died of just 1 disease.... and this repeated itself every single year...
The nations with the highest birth rates per 1000 people are barely at 5%.. the United states has only 1.4% birth rate per year...
You have nothing but a declining population if the numbers are merely at 5% annually... no nation could continue to exist with just that mortality rate annually for all causes of death... let alone 1 disease alone.
So while the numbers are dubious in some reports, the reality is, there is little doubt at this point that subsahara Africa at this point is suffering pandemic from HIV.