Several studies have shown that actions to prevent HIV infection prior to exposure reduce HIV infection in men who have sex with men and transgender women by 44%. These preventative actions include tenofovir disoproxil fumarate and emtricitabine oral drug therapies. This study assessed adherence to these therapies, sexual behaviors, and STI and HIV infection in men who have sex with men and transgender women in STI clinics in San Francisco, Miami, and Washington, D.C. They tested the blood concentration of the drugs, number of sex partners, instances of unsafe sex, and HIV infection. At follow-up visits, 80% of participants had levels of the drug that would be sufficient to protect them from infection. African American populations and those in Miami were less likely to have sufficient blood concentration. Populations with stable housing and those who had more than two unsafe sex partners within the last three months were more likely to have sufficient blood concentration. The study concluded that the more a participant acts on risky behaviors, the more likely they are to be adherent to the preventative therapies.
I was pleasantly surprised by the results of the study. I was expecting the people who have risky behaviors to be less inclined to prevent infection simply because they were participating in the risky behaviors. It bodes well in regards to the HIV epidemic that these people are working to prevent infection, though in a perfect world, all people participating in these behaviors would be adherent to preventative therapies.