Download Increased Sexual Risk Behavior and High HIV Seroincidence

Increased Sexual Risk Behavior and High HIV
Seroincidence among Drug-Using Low-Income
Women with Primary Heterosexual Partners
James M. McMahon, Ph.D.1
Stephanie Tortu, Ph.D.2
Enrique R. Pouget1
Rahul Hamid1
Leilani Torres1
1
2
National Development & Research Institutes, New York, NY
Tulane University School of Public Health & Tropical Medicine, New Orleans, LA
Funding provided by NIH/NIDA grants R01DA10864,
R01DA12805 and R01DA15641
Study Background & Objectives:
• Heterosexual transmission of HIV continues to rise
among women in many parts of the world.
• Previous research has shown that characteristics of
sexual partnerships have an important influence on
HIV risk among women.
• This study examined HIV risk among women drugusers in East Harlem, NYC, to assess women’s
relative risk from different types of sexual partners.
• The findings from this study will help inform the
development of HIV prevention programs tailored to
women’s specific risk partnerships.
Study Setting: East Harlem, NYC
Population size:
Total 117, 000
Racial/Ethnic Composition:
Hispanic 52%
Black Non-Hispanic 36%
White Non-Hispanic 7%
Social/Health Statistics:
Completed high school 56%
Unemployed 17%
Receive public assistance 37%
Income below poverty line 40%
HIV seroprevalence 4.8%
Infant mortality rate 9.7 per 1000 births
Hospitalizations due to drug use 724 per 100,000
East Harlem (“El Barrio”), New York City:
East Harlem HIV Risk Studies Involving Drug-Using
Women and Heterosexual Couples
Study I (DUSC)
Study II (CAR)
Women Drug Users
in Social Context
S. Tortu, PI
A. Neaigus, Co-I
Couples at Risk
Time frame
1996 - 1999
2000 - 2003
Sample
601 drug-using women
353 drug-using women and
their primary partners
Eligibility
>18; female; current use of
crack, cocaine or heroin (IDU
or non-IDU); sexually active
>18; female and male primary
partners; current use of crack,
cocaine or heroin (IDU or nonIDU); sexually active
Recruitment
Street-recruited, clientreferral
Female targeted, streetrecruited, client-referral
Data collection
Survey on demographics, health, sex & drug risk,
risk context & partnerships; all offered HIV, HBV, HCV
counseling and testing
Study
S. Tortu, PI
J.M. McMahon, Co-I
DUSC & CAR Sample Descriptors
Study I
(DUSC)
N= 601 women
Study II
(CAR)
N= 353 couples
Black Non-Hispanic:
Hispanic:
White Non-Hispanic:
55%
39%
6%
40%
44%
13%
Median Age:
Completed High School:
Unemployed:
Homeless:
39
49%
88%
12%
40
F: 47% M: 60%
87%
16%
crack:
Non-IDU cocaine:
heroin:
60%
29%
46%
F: 56% M: 46%
24%
F: 50% M: 44%
IDU (mostly heroin):
27%
37%
HIV and Hepatitis B and C Seroprevalence
Pathogen
HIV
HBV
HCV
Study I
Study II
Study II
Women
Women
Men
23.3%
22.1%
22.0%
(119/510)
(74/335)
(75/341)
52.4%
43.1%
47.8%
(220/420)
(128/297)
(144/301)
43.1%
51.5%
52.7%
(182/422)
(153/297)
(159/301)
Operational Definitions of Sexual Partnerships:
• Primary Male Partner (PMP):
Legal or common-law husband or steady
primary boyfriend of at least one year.
• Sex Exchange Partner:
A sexual partner with whom sex was
exchanged directly for money or drugs.
• Casual Sex Partner:
A sexual partner who is neither a primary
nor exchange partner (e.g., one-time sex
partner or regular casual sex partner).
Concurrent Sexual Partnerships (DUSC n=601):
Prior 6 months self-reported
71%
46%
Primary
41%
Casual
11%
16%
6%
8%
13%
Exchange
5%
32%
Percent Consistent Condom Use by Partner Type
Studies on U.S. Urban Populations
Location/Source
Primary
Casual
Exchange
Time Frame
East Harlem (Tortu-DUSC)
25
43
75
Last intercourse
East Harlem (Tortu-CAR)
22
-
-
Philadelphia (Watkins)
27
52
80
Washington, DC (Williams)
20
52
61
N. California (Ruiz)
30
51
-
East Harlem (Tortu-DUSC)
23
-
-
East Harlem (Tortu-CAR)
19
43
65
Birmingham (Cabral)
24
-
-
U.S. Multisite (Harvey)
24
-
-
Seattle (Baker)
14
26
-
Last 30 days
Last 3 months
Cumulative Unprotected Vaginal Sex (DUSC n=601):
By Partner Type (12 months)
120,000
102,770
100,000
80,000
60,000
40,000
17,980
20,000
7,220
0
Primary
Casual
Exchange
Cumulative Unprotected Anal Sex (DUSC n=601):
By Partner Type (12 months)
1,400
1,220
1,200
1,000
800
600
400
200
5
15
Casual
Exchange
0
Primary
Unprotected Sex by Male+/Female- Couples
By Women’s Awareness of Partner’s HIV Status (CAR, n=39)
80
70
60
50
69%
44%
Unaware
40
31%
30
20
25%
56%
Aware
75%
10
0
Unprotected sex
(last 30 days)
Consistent Condom Use
Women’s Injection Practices
Last Injection Event (DUSC, n=185)
Social/Safe
Receptive
Sharing w/
Primary Partner
30%
Unsafe
11%
Solitary
95%
59%
Solitary: Woman injected alone
Social: Women injected with other IDUs
Women’s Relative Risk of Acquiring HIV from
Different Types of Sex Partners
Risk from PMPs:
More common
Lower condom use
More freq. exposure
Single Partner
Risk from Non-PMPs:
Less common
Higher condom use
Less freq. exposure
Multiple partners
Mathematical Modeling:
HIV Seroincidence Estimated from Self-Reported Risk Behavior
and HIV Transmission Parameters
Primary male partner
P
Male-to-Female Transmission
Probability per Act:
Vaginal intercourse (.001)
Anal intercourse (.02)
Syringe sharing (.01)
Probability of Risk
Partner Being Infected:
0 to 1.0 depending on
partner type and
characteristics
Condom Use:
Rate of effectiveness (.90)
Number of Partners
By partner type
Subject:
uninfected
female druguser
C
S
Casual sex partner
X
Exchange sex partner
F
Friends, family,
running buddy
1. Individual Probability (P) of HIV
Seroconversion:
Bernoulli equations applied to each
individual in the sample to calculate
probability of HIV seroconversion based
on self-reported risk behavior.
2. HIV Seroincidence:
Sample mean P used to calculate
model-based estimate for seroincidence
over the entire sample (number of
seroconversions per 100 person years).
Model-Predicted HIV Incidence (DUSC, n=390)
Seroconversions per 100 person-years
Rate:
Total sample of 390 HIV- women
# of
infections:
2.77
11
From primary partner
2.13
8
From casual partner
0.18
1
From exchange partner
0.46
2
Estimated HIV Seroincidence (DUSC & CAR, n=651)
Seroconversions per 100 person-years
Rate:
Rel Risk:
Model-Predicted HIV Incidence
From primary partner
(subset n=575 with PMPs)
2.54
Ref.
From casual partner
(subset n=79 with casual partners)
1.06
-2.40
From exchange partner
(subset n=122 exchangers)
1.36
-1.87
Actual Observed HIV Incidence
Cohort of repeat testers from DUSC
& CAR: 4 seroconversions of 52
women with PMPs over 3.22 yrs
2.48
(95% CI:
.07, 6.35)
Conclusions:
•
Drug-involved women from East Harlem, New York City…
•
…exhibit one of the highest rates of HIV infection in the
United States
•
…are at greatest risk of acquiring HIV from primary male
partners
•
…continue to engage in sex- and drug-related HIV risk
behavior with infected or high-risk male partners
•
Preliminary data suggest a high rate of HIV seroconversions
among women drug-users with PMPs
•
Interventions promoting “monogamy” may not help these
women avoid disease due to the high risk of acquiring HIV
from primary male partners
Acknowledgements:
This work was supported by research grants from the U.S.
National Institutes of Health/National Institute on Drug Abuse
(R01DA10864, R01DA12805 and R01DA15641).
The authors thank the dedicated staff (former and present) of the
DUSC, CAR & CHIP projects: Sherelle Bonaparte, Jeanine Botta,
Hanifah Burns, Jeanne Campbell, Audrey Grandy-Lampkin, Robert
Quiles, William Rodriguez, and Lee Wengraf.
We also thank the men and women who participated in the DUSC
and CAR studies.