Aidsmap reports that “Gay and other MSM [men who have sex with men] are the group most affected by HIV in the US. Many gay men use recreational drugs, often during sex, and previous research has shown a relationship between consumption of drugs or alcohol and increased HIV risk.”
Is it then not reasonable to assume that the substance abuse rather than the subsequent sexual activity is the more pertinent factor leading to HIV positivity? And if that is the case, it can be argued that the drugs rather than HIV infection are detrimental to the immune system.
Western gay men’s draw to drug abuse likely stems from an imbibed hedonistic culture that arose from social exclusion; though gay liberation emancipated homosexual men, it was a revolution trapped in barbed wire because of a muted handshake from conservative heterosexuals.
In the East, homosexuality is largely hidden and ignored, thus you can’t face prejudice for something you hide, and overarching cultural norms also buffer against substance abuse. Thus, no rampant HIV/AIDS epidemic in Muslim countries.