Wanaitwa wakenya. I think what they may have observed is the apparent weight gain in HIV +ve patients who are on HAART, which is expected anyway as the viral load goes down and general immunity improves. So some might probably have extrapolated that to mean the drugs directly cause weight gain in the said patients and is now 'exploiting' the same ostensibly to 'fatten' chicken.

@Mukiri, I have come across a similar argument in the past. Thing is though, exposure to sub-therapeutic doses of such drugs cannot be ruled out, with the consequent development of resistance to such drugs.

At a place closer to me, there have been persistent claims of some commercial poultry farmers who inject their chicken with what I suspect to be some hormone in an apparent move to fatten and hasten their maturity. It however is quite secretive and I've so far not been able to identify the nature of whatever it is they inject their chicken with.