Population Size Estimates for Men who Have Sex with Men and Persons who Inject Drugs

Abstract

Understanding geographic variation in the numbers of men who have sex with men (MSM) and persons who inject drugs (PWID) is critical to targeting and scaling up HIV prevention programs, but population size estimates are not available at generalizable sub-national levels. We analyzed 1999-2010 National Health and Nutrition Examination Survey data on persons aged 18-59 years. We estimated weighted prevalence of recent (past 12 month) male-male sex and injection drug use by urbanicity (the degree to which a geographic area is urban) and US census region and calculated population sizes. Large metro areas (population ≥1,000,000) had higher prevalence of male-male sex (central areas, 4.4 % of men; fringe areas, 2.5 %) compared with medium/small metro areas (1.4 %) and nonmetro areas (1.1 %). Injection drug use did not vary by urbanicity and neither varied by census region. Three-quarters of MSM, but only half of PWID, resided in large metro areas. Twothirds of MSM and two-thirds of PWID resided in the South and West. Efforts to reach MSM would benefit from being focused in large metro areas, while efforts to reach PWID should be delivered more broadly. These data allow for more effective allocation of funds for prevention programs.KEYWORDS HIV infection, Men who have sex with men, Persons who inject drugs, Risk factors, Gay and bisexual men

Vital Signs: Trends in HIV Diagnoses, Risk Behaviors, and Prevention Among Persons Who Inject Drugs — United States

“…Although acquired immune deficiency syndrome (AIDS) diagnoses among PWID have decreased approximately 90% since their peak in 1993 (1), and only an estimated 0.3% of the U.S. population has injected drugs in the past 12 months (2), approximately 9% of HIV infections diagnosed in recent years are among PWID (3). Although HIV diagnoses among PWID have decreased over time (3), recent increases in acute hepatitis C virus (HCV) infections (4), which are frequently associated with injection drug use, suggest this progress could be negatively affected by increases in opioid (5) and heroin (6) use.…”

Applying National Estimates of Adults With Indications for Pre-Exposure Prophylaxis to Populations of Men Who Have Sex With Men and People Who Inject Drugs in Colorado: Modeling Study (Preprint)

“…At the county level, estimates for recent male-male sexual activity ranged from 1.1% of adult males in nonmetro counties to 4.4% of adult males in large central metro counties. [9] We compared these findings with estimates produced by Grey et al which suggested that 2.4% of the adult male population nationally had a history of sex with men in the past 12 months, and that 3.8% of men in Colorado had had sex with a man in the past 5 years. Male-male sexual activity in Colorado in the past 12 months was not described in the paper by Grey et al County-level estimates ranged from 1% to 6.8% in nonmetro and large central metro counties, respectively.…”

“…[8][9][10][11] The review yielded two publications that described population proportions of PWID, one of which specifically characterized percentage of the populations with history of injection drug use in the past 12 months. [9,12] (See Table 2 for details of the reviewed publications.) The estimates most applicable to our analysis were described by Oster et al, which suggested that 2.5% of the male population nationally and 3% of the males in the Western U.S. had a history of sex with men in the past 12 months.…”

“…Estimates of recent injection drug use at the county urbanicity levels ranged from 0.3% in the large central metro counties to 0.5% in the nonmetro counties. [9] …”

“…[5,8,9] This exclusion is likely to lead to an underestimation of the prevalence of recent injection drug use, thereby leading to an underestimate of the number of PWID with indications for PrEP. A revised estimate of prevalence of PWID that accounts for homeless and incarcerated populations would be of great benefit.…”