Why do homosexual men contract HIV/AIDS more often?
Three main reasons: 1) there are fewer of them (no citation needed) 2) they tend to have more sexual partners than heterosexuals for shorter periods of time 3) male on male sodomy or just sodomy in general carriers a several fold higher risk of HIV transmission than vaginal sex.
I don’t need to cite reason number one since it should be obvious, even in countries where male homosexuality is legally and socially accepted, that there are far fewer male homosexual pairings than heterosexuals couples.
Now reason number two might be a little less obvious but homosexual males tend to have sex earlier than heterosexuals males and report ‘longer periods of partnership acquisition, a higher prevalence of partnership concurrency, and more age disassortative mixing than heterosexuals.’
Male homosexuals report a median of 2-4x as many sexual partners as heterosexual men within the last year and almost 7x as many before 40 years of age:
At all ages, heterosexual men and women reported a median of 1 partner in the past year, while MSM reported a median of 4 partners in UMHS and 2–3 male partners in SEA. MSM reported significantly more lifetime partners than heterosexual men and women at all ages (p<0.01 for each age group). The median lifetime number of sex partners among those aged 18–24 was 4 in heterosexuals and 15 in UMHS MSM, and among persons age 35–39, was 10 and 67, respectively. (The SEA did not ask about lifetime number of partners.)
And they will be much more likely to find new sexual partners in their 30′s when most heterosexual couples have paired off:
among participants aged 35–39, 50.0% of heterosexual men and 68.2% of heterosexual women reported that at least 5 years had passed since the start of their most recent partnership. Only 11.2% of UMHS MSM and 14.2% of SEA MSM in the same age range reported this. Consequently, MSM in each age group reported longer periods of new partner acquisition than heterosexuals, defined as the amount of time from sexual debut to the start of the most recently formed partnership. Because the age-specific means for heterosexual men and women, and MSM in both surveys, were so similar (within 1–3 years), we combined the data for these respective groups. Among participants ages 35–39, MSM reported an average of 20.2 years of new partner acquisition compared with 11.9 years among heterosexuals. This difference between heterosexuals and MSM increased linearly with age (p<0.01 for interaction).
Homosexual men are the vast majority of HIV cases even with higher rates of condom use.
There is a simple reason for this: sodomy carries a several fold higher transmission risk not negated by higher rates of condom use.
From Stanford Medicine:
“A meta-analysis exploring the risk of HIV transmission through unprotected anal sex was published in 2010.The analysis, based on the results of four studies, estimated the risk through receptive anal sex (receiving the penis into the anus, also known as bottoming) to be 1.4%. (This means that an average of one transmission occurred for every 71 exposures.)”
“A meta-analysis of 10 studies exploring the risk of transmission through vaginal sex was published in 2009.4 It is estimated the risk of HIV transmission through receptive vaginal sex (receiving the penis in the vagina) to be 0.08% (equivalent to 1 transmission per 1,250 exposures).”
This is the actual study published in the International Journal of Epidemiology