This is in the UK not Ireland.
Personally I suspect that if Irish statistics are anything to go on, that much of this may be due to people already infected entering the UK, largely from Sub-Saharan Africa. I refer to this study in the Lancet in the UK, showing Black gay men are more than twice as likely to have HIV-AIDS as whites. http://www.aidsmap.com/Black-gay-men-in-the-UK-almost-twice-as-li etc ...
I did have a friend in the past who had lived with HIV since the early 1990s and when I knew him he told me his viral load was tiny, as if it wasn't present in his blood, and that doctors told him he was in the top 1% of healthy HIV patients. Recently though my mother told me he was in hospital I think with cancer (not sure it's cancer though - he is a heavy smoker). I don't know if that has anything to do with the HIV.
I think the success of anti-HIV drugs in preventing it progressing to AIDS may be making some complacent.