Transcript HIV/STD Risk Behaviors in Methamphetamine User Networks Steve

HIV/STD Risk Behaviors in
Methamphetamine User
Networks
Steve Shoptaw, Ph.D.
Pamina Gorbach, Dr.P.H.
UCLA
Objectives
Examine diffusion of HIV and STDs through
sexual networks of drug using and non-drug
using, high-risk individuals in Los Angeles
County at the:
• Individual-level
• Partner-level
Among:
– Men who have sex with men (MSM)
– Men who have sex with men and women
(MSM/W)
AND
Their partners….
Overview
• Stimulant use, particularly
methamphetamine use, effects the
transmission of HIV and STDs in Los
Angeles County and the urban Western
U.S.
• Methamphetamine is a “sex drug” that
facilitates commission of HIV-related
sexual risk behaviors in MSM and
MSM/W
– Injection risks are a relatively minor
component of the spread of HIV in the West
The Los Angeles AIDS Epidemic:
Cumulative Male AIDS Cases
MSM
Los Angeles*
76%
United States**
57%
MSM and IDU
7%
8%
IDU
6%
24%
Other
11%
11%
Percent HIV+
Methamphetamine and HIV in MSM:
A time-to-response association?
100
90
80
70
60
50
40
30
20
10
0
Probability
Sample1
Street
Recreational Outpatient Residential5
Outreach2
User3
Drug free4
I was so tweaked…..
…I didn’t care how he screwed me.
Why Methamphetamine for MSM?
• Methamphetamine use and increase in sexual
libido among MSM and MSM/W first noted in
1970s
– Increased energy
– Decreased appetite
– Euphoria
– Psychomotor agitation
– Heightened interest in sex
– Delayed orgasm – longer and rougher sex
episodes
• Potential for this group to be “bridge” for
infectious disease to general population
Drug Use and Infection Risks for
MSM and MSM/W
• Incidence of HIV infection among San Francisco
MSM is 1.2-2% per 100 ppy (Stall et al., 2000)
– Incidence in Seattle STD clinic is 26% per 100 ppy
(Golden, 2003)
• Local and national increases in infectious diseases
and risk behaviors among MSM and MSM/W
•  gonorrhea
•  risk behaviors among HIV- and HIV+ (Craib et
al., 2000) and among MSM on HAART (Vanable
et al., 2003)
• Caucasians prefer methamphetamine; men of color
prefer alcohol; cocaine
Factors Effecting STI/HIV
Transmission among Drug Users
for Any Sexual Event
• The risk behaviors (± IDU, vaginal/anal
sex, with/without barriers,
insertive/receptive, using drug/not)
• The partnership (1° partner/not,
monogamous/concurrent, gender and
sexual network characteristics)
• The social context (high risk
environment/not)
How do Partnership Dynamics
Influence HIV/STD Transmission?
?
• Types of partnerships
• Condom use
• Partnership dynamics
• Drug use
• Concurrency
• Disease transmission
Study Approach
• Collect biomarkers and self-report data from
index participants and their sexual partners
to model the diffusion of STIs/HIV among
drug users
• Analysis proposes triangulation of
biomarkers (blood, urine for HIV, gonorrhea,
syphilis, methamphetamine, cocaine, opiates,
marijuana) to provide prevalence, incidence
on STI/HIV
• Qualitative information describes
partnerships
• Modeling to evaluate movement of infections
and drug use
Representative Sampling Cohort
Design (N=1,200)
Index Participants and Nominated Participants
Drug-using MSM/W and
(n=240)
Sexual Partners
(96 males, 96 females)
Drug-using MSM
and
Sexual Partners
(n=240)
(96 males)
Non-drug-using MSM/W and
(n=240)
Baseline
STD/Drug
Self-Report
Sexual Partners
(96 males, 96 females)
6 Months
Drug Self-Report
12 Months
STD/Drug
Self-Report
Design Discussion
• Observing infectious disease, sex risks, and
partnership factors among MSM and
MSM/W drug users over time in
representative cohorts allows accuracy in
predicting spread of HIV/AIDS in Los Angeles
region
• Non-drug using MSM/W comparison group
• One-year observation period for completion of
the study within time and budget
• Small, ego-centered networks have limits, but
can be completed
– Ethnography may provide description on larger
networks
Network Structure and HIV/STDs
• Individual and partnership-level data
can provide sufficient data to model
spread of STDs in a full network (Eames
et al., 2002)
• Integration of ethnographic, self-report,
and biological markers using modeling
– CASI to measure amount of behaviors
– Ethnography to capture meaning of
behaviors
– Biomarkers to detect drug use, STD/HIV
status
Enrollment of MSM, MSM/W
• Relatively public places frequented
by the men (strolling areas) or highrisk venues (bathhouses, sex clubs,
parks, bookstores)
• STD clinics
• Representative sampling plan
• 18-20 men enrolled weekly plus their
sexual partners
Eligibility Criteria: Index Participants
• Behaviorally identified MSM, MSM/W
– Drug users must self-report monthly use over
past 6 months and on 2+ occasions in past 30
days
– Alcohol users must report 5+ drinks per
drinking day at least monthly and on 2+
occasions in past 30 days
• Willing to provide at least 1 or 2 (for
MSM/W, 1 male, 1 female) sexual partners
with information about contacting study
staff to consider enrolling
Partner Participants
• Maximum of 480 participants; 120 female
• Must be male or female sexual partner of
an index participant
– No known methods for implementing a
probability-based sampling frame for
partners
– May select for stable partners, though >25%
of partnerships among youth seen in STD
and FP clinics dissolve in 3 months; 60% in 1
year; 8-9 weeks average duration (Gorbach,
2003)
Two Sites
(1) Hollywood, West Hollywood,
Silverlake areas of Los Angeles
– Highest concentrations of MSM and
MSM/W of color in Los Angeles
County
(2) Long Beach, Belmont Shore areas
Venue based sampling to occur at L.A.
County and Long Beach STD clinics