title: Contribution of Anal Sex to HIV Prevalence Among Heterosexuals: A Modeling Analysis.
abstract: Anal intercourse is reported by many heterosexuals, and evidence suggests that its practice may be increasing. We estimated the proportion of the HIV burden attributable to anal sex in 2015 among heterosexual women and men in the United States. The HIV Optimization and Prevention Economics model was developed using parameter inputs from the literature for the sexually active U.S. population aged 13-64. The model uses differential equations to represent the progression of the population between compartments defined by HIV disease status and continuum-of-care stages from 2007 to 2015. For heterosexual women of all ages (who do not inject drugs), almost 28% of infections were associated with anal sex, whereas for women aged 18-34, nearly 40% of HIV infections were associated with anal sex. For heterosexual men, 20% of HIV infections were associated with insertive anal sex with women. Sensitivity analyses showed that varying any of 63 inputs by ±20% resulted in no more than a 13% change in the projected number of heterosexual infections in 2015, including those attributed to anal sex. Despite uncertainties in model inputs, a substantial portion of the HIV burden among heterosexuals appears to be attributable to anal sex. Providing information about the relative risk of anal sex compared with vaginal sex may help reduce HIV incidence in heterosexuals.
authors.affiliation: Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 1600 Clifton Road, MS E-37, Atlanta, GA, 30329, USA. aoleary@cdc.gov.
authors.forename: Ann
authors.identifier: http://orcid.org/0000-0001-8129-3121
authors.initials: A
authors.lastname: O'Leary
authors.affiliation: Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 1600 Clifton Road, MS E-37, Atlanta, GA, 30329, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: DiNenno
authors.affiliation: RTI International, Research Triangle Park, Durham, NC, 27709, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Honeycutt
authors.affiliation: RTI International, Research Triangle Park, Durham, NC, 27709, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Allaire
authors.affiliation: RTI International, Research Triangle Park, Durham, NC, 27709, USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Neuwahl
authors.affiliation: RTI Health Solutions, Research Triangle Park, Durham, NC, 27709, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Hicks
authors.affiliation: Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 1600 Clifton Road, MS E-37, Atlanta, GA, 30329, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Sansom
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000517:prevention & control; D020010:Heterosexuality / Q000523:psychology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012309:Risk-Taking; D012725:Sexual Behavior; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: Anal intercourse; HIV; Heterosexual