STIs in a multi-site sample of high-risk, substance-using MSM: Baseline results from Project MIX Gordon Mansergh, PhD National STD Prevention Conference March 2008 - Chicago The findings and conclusions in this report are those of the author and do not necessarily represent the views of the Centers for Disease Control and Prevention

Overview Study Background Sample Characteristics STIs & Associated Factors Summary & Implications

Substance-using MSM in the U.S. Background Substance use is associated with sexual risk for STI transmission among MSM Heightened STIs among MSM samples in this decade Objective Better understand factors associated with reported STIs among high risk, substance-using MSM

Project MIX Study Group CDC (Division of HIV/AIDS Prevention) – Gordon Mansergh, Steve Flores, Raekiela Taylor, Cathy Zhang, David Purcell, Pilgrim Spikes, other data management and analysis staff et al. Chicago (UIC & Howard Brown Health Center) – David McKirnan, Jenny Hopwood et al. Los Angeles (Health Research Association) – Sharon Hudson, Bobby Gatson et al. New York City (NY Blood Center & NY Academy of Medicine) – Beryl Koblin, Victoria Frye, Krista Goodman et al. San Francisco (San Francisco DPH) – Grant Colfax, Tim Matheson et al.

Project MIX Uniqueness Large, multi-city sample with very high risk eligibility: Unprotected anal sex with a man in the past 6 months Anal sex with a man while drunk or high in the past 6 months Diverse participant “mix”: HIV+ and HIV- men Over-sampled Black and Latino men Different substances of choice and patterns of use Variety of income and education levels, and age groups Variety in non/gay identification and born in US

Methods Recruitment: staff outreach, ads, and snowball in 2005-6 Measurement: ACASI self-reported demographic and behavioral characteristics at Baseline HIV status STIs in past 12 months Substance use during most recent anal sex encounter with non-primary partner in past 3 months Analysis: Multivariate logistic regression for STIs (models include all listed variables)

Table 1. Baseline sample characteristics for Project MIX (n=1540) Sample Characteristics % (n) --------------------------------------------------------------------------------- HIV-status (self-reported)# Negative 44 (685) Positive 47 (724) Unknown 9 (131) Sexual orientation (self-reported)# Gay/homosexual/queer 84 (1288) Bisexual 14 (221) Other 2 (31) Race/ethnicity White 38 (589) Black 32 (492) Latino 19 (293) Other 11 (166) Age group (years) 18-29 27 (409) 30-39 34 (525) 40+ 39 (606) Education High school diploma or less 32 (484) Some post-high school education 34 (529) College degree or higher 34 (527) Study site Chicago 27 (411) Los Angeles 23 (356) New York City 23 (362) San Francisco 27 (413) Born outside United States 14 (223) -------------------------------------------------------------------------------- #For subsequent analyses: HIV-unknowns are combined with HIV-negative men; bisexuals are combined with “other” self-identification

Table 2. Self-reported STIs at baseline for Project MIX (n=1540) Reported having an STI in the past 12 months: 33% any STI 13% gonorrhea 11% syphilis 8% Chlamydia 14% other/undetermined STI

Table 3. Behavior during most recent anal sex encounter with a non-primary partner for Project MIX at baseline (n=1540) Behavioral Characteristics % (n) ------------------------------------------------------------------------------------------ Sexual risk behavior Unprotected receptive (URA) 39 (600) HIV-discordant URA (DURA) 21 (326) Unprotected insertive (UIA) 37 (563) HIV-discordant UIA (DUIA) 19 (291) Substance use before or during sex 77 (1108) Alcohol 58 (893) Other drug 58 (892) Marijuana 23 (352) Methamphetamine 18 (285) Poppers/amyl nitrite 13 (208) Crack 13 (206) Cocaine 9 (139) Viagra/Cialis/Levetra 8 (119) Other drugs 12 (189) Multi-substance use (>1 substance) 46 (710) ---------------------------------------------------------------------------------------------------------- Substances with <5% use prevalence were combined into “other” substance use, #Age groups used to categorize partners as Younger or Older than the respondent were 18-29, 30-39, and 40 or more years old.

Table 4a. Sample characteristics and reported STIs in the past 12 months at baseline for Project MIX participants (n=1540) Variables associated with STIs in past 12 months (multivariate results ----------------------------------------------------------------------------------------- Any STI Sample Characteristics OR (CI) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Reported HIV-status Positive 1.6 (1.2-2.0) Negative/unknown (ref) Reported sexual orientation Gay/homosexual Bisexual/other (ref) Race/ethnicity Black Latino Other White (ref) Age group (groups) 18-29 1.5 (1.1-2.0) 30-39 40+ (ref) Education HS diploma or less Some post-HS educ College deg or more (ref) Born in United States Not born in US (ref) Substance use during last sex with a non-primary partner Alcohol use 0.7 (0.6-0.9) No alcohol use (ref) Drug use No drug use (ref) Multi-substance use (2+) No multi-subst use (ref) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- STI, sexually-transmitted infection; multivariate analyses include all variables listed; OR=Adjusted Odds Ratio; CI=95% confidence interval

Table 4b. Sample characteristics and reported STIs in the past 12 months at baseline for Project MIX participants (n=1540) Variables associated with STIs in past 12 months (multivariate results) ----------------------------------------------------------------------------------------- Any STI Gonorrhea Sample Characteristics OR (CI) OR (CI) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Reported HIV-status Positive 1.6 (1.2-2.0) 1.6 (1.1-2.2) Negative/unknown (ref) Reported sexual orientation Gay/homosexual Bisexual/other (ref) Race/ethnicity Black Latino Other White (ref) Age group (groups) 18-29 1.5 (1.1-2.0) 1.7 (1.1-2.6) 30-39 40+ (ref) Education HS diploma or less Some post-HS educ College deg or more (ref) Born in United States Not born in US (ref) Substance use during last sex with a non-primary partner Alcohol use 0.7 (0.6-0.9) No alcohol use (ref) Drug use No drug use (ref) Multi-substance use (2+) No multi-subst use (ref) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- STI, sexually-transmitted infection; multivariate analyses include all variables listed; OR=Adjusted Odds Ratio; CI=95% confidence interval

Table 4c. Sample characteristics and reported STIs in the past 12 months at baseline for Project MIX participants (n=1540) Variables associated with STIs in past 12 months (multivariate results) ----------------------------------------------------------------------------------------- Any STI Gonorrhea Syphilis Sample Characteristics OR (CI) OR (CI) OR (CI) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Reported HIV-status Positive 1.6 (1.2-2.0) 1.6 (1.1-2.2) 3.9 (2.6-5.9) Negative/unknown (ref) Reported sexual orientation Gay/homosexual Bisexual/other (ref) Race/ethnicity Black 1.6 (1.0-2.5) Latino Other White (ref) Age group (groups) 18-29 1.5 (1.1-2.0) 1.7 (1.1-2.6) 30-39 40+ (ref) Education HS diploma or less Some post-HS educ College deg or more (ref) Born in United States Not born in US (ref) Substance use during last sex with a non-primary partner Alcohol use 0.7 (0.6-0.9) 0.5 (0.4-0.8) No alcohol use (ref) Drug use No drug use (ref) Multi-substance use (2+) No multi-subst use (ref) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- STI, sexually-transmitted infection; multivariate analyses include all variables listed; OR=Adjusted Odds Ratio; CI=95% confidence interval

Table 4d. Sample characteristics and reported STIs in the past 12 months at baseline for Project MIX participants (n=1540) Variables associated with STIs in past 12 months (multivariate results) ----------------------------------------------------------------------------------------- Any STI Gonorrhea Syphilis Chlamydia Sample Characteristics OR (CI) OR (CI) OR (CI) OR (CI) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Reported HIV-status Positive 1.6 (1.2-2.0) 1.6 (1.1-2.2) 3.9 (2.6-5.9) Negative/unknown (ref) Reported sexual orientation Gay/homosexual Bisexual/other (ref) Race/ethnicity Black 1.6 (1.0-2.5) 0.5 (0.3-1.0) Latino Other White (ref) Age group (groups) 18-29 1.5 (1.1-2.0) 1.7 (1.1-2.6) 30-39 40+ (ref) Education HS diploma or less Some post-HS educ College deg or more (ref) Born in United States Not born in US (ref) Substance use during last sex with a non-primary partner Alcohol use 0.7 (0.6-0.9) 0.5 (0.4-0.8) No alcohol use (ref) Drug use No drug use (ref) Multi-substance use (2+) No multi-subst use (ref) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- STI, sexually-transmitted infection; multivariate analyses include all variables listed; OR=Adjusted Odds Ratio; CI=95% confidence interval

Summary & Implications These are indeed high risk MSM to be targeted for risk reduction (i.e., UA and STIs) HIV+ status is associated with several STIs, particularly syphilis Younger age is associated with gonorrhea Black race is associated with syphilis, and white race with Chlamydia Implications Even among very high risk, substance-using MSM, subgroups of men should be targeted with STI risk reduction messages However, all MSM who use substances during sex could potentially benefit from risk reduction efforts

? gmansergh@cdc.gov