Higher Concentration of HIV RNA in Rectal Mucosa Secretions than in Blood and Seminal Plasma, among Men Who Have Sex with Men, Independent of Antiretroviral Therapy

High levels of human immunodeficiency virus (HIV) in rectal secretions and semen likely increase the risk of HIV transmission. HIV-infected men who have sex with men made 2–3 study visits, over 4 weeks, to assess rectal, seminal, and plasma levels of HIV RNA. Mixed-effects models estimated the effect of factors on HIV shedding. Twenty-seven (42%) of 64 men were receiving antiretroviral therapy (ART); regardless of ART use, median HIV RNA levels were higher in rectal secretions (4.96 log10 copies/mL) than in blood plasma (4.24 log10 copies/mL) or seminal plasma (3.55 log10 copies/mL; P< .05, each comparison). ART was associated with a 1.3-log10 reduction in rectal HIV RNA in a model without plasma HIV RNA; with and without plasma RNA in models, ART accounted for a >1-log10 decrease in seminal HIV RNA levels. Thus, controlling for plasma HIV RNA, ART had an independent effect on seminal, but not rectal, HIV levels.