Why do gay and bisexuals have the highest rates of hiv infection?

More partners: Gay or bisexual couples are not more prone to hiv except as explained by more partners; monogomous partners have the same risk as heterosexual couples, very very low ted butler md.

Unsafe anal sex: The rectal mucosa is especially vulnerable to infection by the HIV virus. This is part, but by no means all, of the answer. Hiv was first discovered in gay-bi subcultures where promiscuity and lack of barrier protection allowed widespread infection. Being bi or gay by itself does not put one at any extra risk; the danger is entirely in the behaviors.