I think the reason that no countries come to usa with aide, is that it generally doesn't need it. Money, the country has abundances, food the same, military supplies, well, I dont even need to comment on this, medical supplies, the country has plenty. If a disaster like this was to happen in Britain today for instance, it would not require aide. The same with Germany, Sweden, France, most of the larger European countries. Australia would be in the same situation. If the disaster was great enough, then medical aide would probably be required, but for a disaster of magnitude that the USA has endured in the last few decades, it would not.
And it also comes down to another thing... does the US government actually request assistance? I'm not sure if they do so can't make a firm comment, but I get the impression that the government has enough faith in their capabilities that they do not request it, and if it is offered, they probably kindly decline.