Not in the United States - but it is my understanding that AIDS is common in heterosexual people in areas hardest hit, like sub-Saharan Africa. Some countries have infections as high as 20%, which seems very likely to include more straight people than gay people.

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.