Of course, HIV is a lot like this. A single infectious particle can be fatal. And, as with the West Nile-like virus, it doesn't respect geographic borders. But in contrast to the West Nile-like virus, HIV changes rapidly. If we don't stop HIV everywhere in the world, we've stopped it nowhere.
Women are at particular risk worldwide.
In the United States, one in three new cases of HIV infection now occurs in a woman. It is also the topic of an article in this issue by Dr Tracy Wilson. Simply put, there is a tendency for bad things in an epidemic to get worse, increasing the range and severity of that outbreak. We know that these are important issues because the rate of HIV infection, which had been declining markedly in the United States for several years, is no longer declining at such a rate. The risk for becoming infected is particularly high among adolescents.