Thanks Kreedo, and I'm so sorry that you've experienced the same, it's terrifying and heartbreaking. If your son's kidneys came back after 16 days there's a very good chance he'll make a full recovery. We were told that if DD's started working within two weeks of the HUS and reanl failure, it was unlikely there would be any long-term damage. Sadly, her kidneys didn't start working at all until after five weeks. When she was taken into PICU her creatinin levels were 300+, they plateaued out at 70, giving her 30% function around 8 months later. Six months ago, they had dropped to 57, giving her 40% function, something her consultant didn't think would happen (how we put all our faith in them when they deliver good news, but want them to be wrong when the news is bad) but her consultant has warned that the latest bloods may show an increase to the mid-60s, simply because she's growing so well (a blessing in itself since, I'm sure you are aware, kidney patients tend not to develop very well). Please don't read anything into the creatinin/function equations though, as DD's consultant always says, creatinin is simply a marker and they take lots of other factors into consideration before coming up with a kidney function diagnosis (how well the child is growing, how well they're eating, their general energy levels, how the kidneys are developing - your son should have a kidney ultrasound a year after the HUS to determine if they are growing with his body, DD's are, thank goodness - potassium levels etc).
Please come back and let me know how your son is doing. I met lots of parents of kidney patients at GOSH, but all of the children had been born with problems, none, like DD, had developed problems because of this awful and seemingly random syndrome. When I asked one of DD's doctors he told me that they don't know why, of all the children who get a chest infection, i.e. pneumonia, in a miniscule percentage, it mutates into HUS. His exact words were: 'Maybe some children have something in their genetic make-up that allows the HUS to take hold, or maybe it's just terrible bad luck, we simply don't know'. I do know that there's three types of HUS, off pneumonia, off e-coli, and then the HUS that seems to develop out of nowhere. The first two have the worst immediate effects, but the best long-term prognosis.
Anyway, I could go on about this forever, so I'll stop myself now. I hope your little boy makes a full recovery. If there's anything you want to know about meds etc, I'll share with you what I know.