Officially, HAI stands for healthcare associated infection these days. Healthcare because, as we've already seen, it doesn't have to be a hospital per se that is the root of the infection. Associated because there's never very much proof that such infections come from particular places. If it's MRSA, sure they'll genetically fingerprint the isolate so that they can type it and work our where you fit within the context of any outbreak, but a chest infection probably won't be followed up like that. Plus, as you say, it might be an infection caught in hospital...from your own husband, who happens to carry MRSA or Neiserria menigitidis (one of the bacteria which will cause menigitis, and which is carried in the noses of 10% of people). The trouble with people in hospital is that, generally speaking, they are ill. Which means that any bug, which when encountered by you or I would be taken care of in a flash by our immune system, can cause serious infection. Incidentally, hand washing isn't the way forward. Soap and water involves the mechanical removal of organisms. Most people aren't very good at it. Alcohol handrubs kill organisms on any surface of the hands they touch, can be used as you walk through a ward, and are less drying to the skin. Believe you me, it's no surprise that healthcare workers don't wash their hands as much as they should- you try washing your hands every ten minutes for a nine hour day. They'll be red and raw by the end of it. Hand Hygiene. Very Important. rant over.