You claim the majority of HIV patients in the United States are heterosexual. Do you have any evidence of this? It cuts against everything I have ever read on the topic and everything I and other people in this thread can churn up.
The United States only has a fraction of the world's HIV or AIDS cases, so it seems plausible that worldwide straight people could still represent the majority of cases.
It does seem difficult to get reliable estimates outside the US & Europe, though.