Is it true that homosexuals are more likely to transmit diseases like hiv-1 and hiv-2 sexually?

HIV: Is due to annal intercourse. This causes significant annal mucosal injury, micro tears which is a easy port of entry to HIV and other std or bacteria (your own stool bacteria- causing anal abscess). Reality is that any one is prone to hiv. All it needs is a port of entry (thru' broken mucosa or skin). Anal intercourse is an easier port of injury due to above reason.

Depends: In sub-saharan africa most cases of hiv/aids are heterosexually transmitted. Hiv can be transmitted by both homo- & heterosexuals via anal or vaginal intercourse or by IV drug users sharing needles.

No, but depends: No, it is not necessarily true that homosexuals are more likely to transmit hiv-1 and hiv-2 sexually. It ultimately comes down to the risk behavior of the specific sexual act that leads to HIV infection. Unprotected anal intercourse is the most risky, but whether that occurs with two men or a man and woman, the risk is the same. Unprotected vaginal intercourse is less risky followed by oral sex.