In South Africa, you can get ARVs free through the government if your CD4 count is below a certain level or you are classified as having progressed from HIV to AIDS. To be classified as having AIDS, you must have an illness that only people with weak immune systems can get.

If you're HIV+ it's a good idea to have your CD4 count tested regularly so that you can go on treatment as soon as you need it. If you wait until you are really ill, it'll take a lot longer for the treatment to make you better (and in fact may not work at all – some people die because they waited too long for treatment).