The biggest write-ups of teh CAS are from, in order, the Neo-Anarchist's Guid eto North America, Shadows Across North America, and Dirty Tricks.
Australia's original write-up is in Target: Awakened Lands, but had been mentioned at least in passing a few times before and since.
Africa... *sigh* ... Africa is criminally underused. A few of us are working on that, but it's not a major source of attention at this time. (You can start to see hints in Chrome Flesh, however.)
In previous editions, Africa was either "Tribal warfare" in Nigeria, "Radioactive Wasteland" for Libya, "Elves" for South America, and "Deepest Darkest" for most of the rest. It's ... it's been treated really, really badly over the years. Absolute shame. I know it isn't exactly a gaming Mecca (Hah, because Mecca is in ... okay, nevermind...) but there should be a lil' love sent that-a-way, right?