Abstract Book Vol. 1 [International Conference on AIDS (16th: 2006: Toronto, Canada)]

Monday
14 August

injection (AOR=3.05; 95%CI: 1.04, 8.96) was also independently associated
with needle sharing in Juarez.
Conclusions: Common environmental factors influenced needle sharing
practices in these settings, suggesting that structural-level interventions
addressing policing and interventions based in shooting galleries are warranted
to avert a potentially explosive HIV epidemic.
MOPE0337
High-risk sexual networks of indoor commercial
sex workers (CSW), their clients, and other sexual
partners in Vancouver, Canada
V.P. Remple', D.M. Patrick', M.W. Tyndall', C. Johnston3, A.M. Jolly4.
IBC Centre for Disease Control, Vancouver, Canada, 2BC Centre for Excellence
in HIV/AIDS, Vancouver, Canada, 3Asian Society for the Intervention of AIDS,
Vancouver, Canada, 4Public Health Agency of Canada, Ottawa, Canada
Background: The objectives were to determine the structure of CSW' sexual
networks, and the potential for HIV propagation within the networks and to
lower risk, general populations.
Methods: In-depth interviews elicited egocentric network data from CSW in
Vancouver-area massage parlours (MP), yielding dyadic and second-order sex
partnerships data on their most recent 5-10 sex partners.
Results: Between June, 2004, and January, 2006, interviews were conducted in
seven parlours with 49 CSW yielding 275 sexual partners, 245 (89%) of whom
were commercial clients. CSW reported a median of 25 (IQR 12-48) partners
per month, and provided proxy data for a median of 6 (IQR 4-7) partners. None
reported injection drug use, and one was HIV-infected. Inconsistent condom
use was reported with clients by 9% and with non-clients by 63%. There was
a single, connected sexual network of 535 individuals with a high frequency
of dense, cyclic microstructures. CSW identified 21% of the clients as house
regulars (HR); men who frequented the parlour and had sex with all of the
workers. Compared to other clients, HR were significantly more central within
the network, and were more likely to be members of microstructures. Fifty-two
percent both of clients (95%CI 41-54%o) and CSW (95%oCI 37-68% ) bridged to
the general population through intimate partners, and 36% (95%CI 30-49%)
of clients bridged between sex venues throughout the Vancouver area, other
parts of Canada, and Asia.
Conclusions: Social network analysis provides valuable tools with which to
examine HIV and sexually transmitted infection (STI) risk at the individual,
dyadic, and network levels. The potential for propagation of HIV and other STI
throughout the MP networks and to the lower risk, general population is high.
Outreach education should focus on 100% condom use with with all partners,
and should target HR, focussing on minimizing the number of concurrent CSW
partners.
MOPE0338
Frailty and time from HAART initiation to AIDS or
death
L. Desquilbet', J.B. Margolick2, L.P. Frieda, J.P. Phair4, C.M. Williams',
B.D. Jamieson6, M. Holloway', L.P. Jacobson'. 'Johns Hopkins School of
Public Health, Dept of Epidemiology, Baltimore, Maryland, United States,
'Johns Hopkins School of Public Health, Dept of Molecular Microbiology and
Immunology, Baltimore, Maryland, United States, 3Johns Hopkins School
of Medicine, Division of Geriatric Medicine and Gerontology and Dept of
Medicine, Baltimore, Maryland, United States, 4Northwestern University,
Howard Brown Health Center and Dept of Medicine, Chicago, Illinois,
United States, 5National Institutes of Health, National Institute of Allergy
and Infectious Diseases, Bethesda, Maryland, United States, 6David Geffen
School of Medicine, UCLA, Medicine, Los Angeles, California, United States,
'University of Pittsburgh, Dept of Infectious Diseases and Microbiology,
Pittsburgh, Pennsylvania, United States
Background: In the general population, frailty represents a late stage of the
aging process and is a predictor of morbidity and mortality. We investigated the
association between a frailty-related phenotype (FRP) and incidence of clinical
AIDS or death after HAART in HIV-infected men.
Methods: Based on a published five-criterion definition of frailty in HIVnegative older adults [Fried et al., J Gerontol A Biol Sci Med Sdi, 2001], FRP was
defined among 1,977 HIV-negative men in the Multicenter AIDS Cohort Study
(MACS) using four of these criteria. We then studied its effect among all 661
HIV-positive men in the MACS with data before and after initiation of HAART.
Time from HAART initiation to clinical AIDS (or to a new clinical AIDS diagnosis
for those who had AIDS at HAART initiation) or death was investigated through
Kaplan-Meier methods and Cox proportional hazards models. Main exposures
included presence of FRP and an AIDS diagnosis before HAART initiation.
Associations were adjusted for age, ethnicity, educational level, CD4 cell count
and viral load at HAART initiation.
Results: Before HAART initiation, 475 men were AIDS- and FRP-free, 95 had
AIDS but no FRP, 40 had FRP but no AIDS, and 51 had both FRP and AIDS.
A total of 143 events were observed during follow-up from HAART initiation

(median, 6.9 years). Both AIDS and FRP prior to HAART were associated with
time to AIDS or death (P logrank < 0.01). After adjustment, those with FRP
[Adjusted relative risk (ARR), 1.7; 95% confidence interval (CI), 1.2-2.6)
and with AIDS (ARR, 1.5; 95% CI, 1.0-2.2) prior to HAART initiation were
independently more likely to develop AIDS or to die after HAART.
Conclusions: FRP before HAART initiation was a strong predictor of worse
prognosis after HAART, independent of CD4 count, viral load and clinical AIDS
status prior to HAART.

MOPE0339
Hormonal contraception and risk of incident HIV
infection among South African women:
a prospective study
L. Myer, L. Denny2, T.C. Wright3, L. Kuhn4. 1Infectious Diseases Epidemiology
Unit, School of Public Health & Family Medicine, University of Cape Town,
Cape Town, South Africa, 2University of Cape Town, Department of Obstetrics
& Gynaecology, Cape Town, South Africa, 3Columbia University, Department
of Pathology, College of Physicians & Surgeons, New York, United States,
4Columbia University, Gertrude Sergievsky Center, New York, United States
Background: Many women using hormonal contraceptives (HC)e O are also at risk
of sexually-transmitted HIV infection. However evidence is mixed on whether
HC increases women's risk of HIV. A number of sex worker cohorts have found
significant increases in HIV incidence among HC users, in contrast to null
results from several population-based studies. We investigated associations
between HIV incidence and use of combined oral contraceptives (COC), and
the injectable contraceptives norethindrone enanthate (NET-EN) or depot
medroxyprogesterone acetate (DMPA), in a large general population cohort of
South African women.
Methods: Participants were 4200 HIV-negative women enrolled into a
cervical cancer screening trial. At enrollment, women were tested for sexually
transmitted infections and reported on their sexual behaviors and HC use.
Participants were followed for up to 24 months with repeated measures of HIV,
sexual behaviors and HC use.
Results: During 5010 person-years of follow-up, 111 incident HIV infections
were observed (HIV incidence, 2.2 infections/100 person-years). At enrollment,
21% of women reported using a form of HC, primarily DMPA (14% of all
women) or NET-EN (5%). After adjusting for sexual risk behaviors and sexually
transmitted infections, the incidence of HIV was similar among women using
COC, NET-EN or DMPA compared to women not using any HC (incidence
rate ratios and 95% confidence intervals, 0.65, 0.16-2.66; 0.79, 0.31-2.02
and 0.96, 0.58-1.59, respectively). There was also no association between
increased duration of DMPA use and HIV incidence (p-value for trend, 0.51).
Conclusions: These findings contribute to the evidence from general population
cohorts that HC use is not associated with increased risk of women's HIV
infection. We hypothesize that methodological differences in the measurement
of and adjustment for sexual behaviors, which confound the association
between HC and HIV acquisition, are responsible for the mixed findings from
previous research. Family planning services remain an important venue for HIV
prevention activities.
MOPEO34O
HIV incidence and risk factors for HIV transmission
in an HIV vaccine feasibility study in rural Uganda
E. Ruzagira', A. Kamali', A. Bwanika', U. Bahemuka', M. Price2,
H. Grosskurth'. 'Medical Research Council/Uganda Virus Research Institute
Unit on AIDS, Entebbe, Uganda, 2International AIDS Vaccine Initiative, New
York, United States
Background: Data on HIV incidence and risk factors for infection will be
essential for determining the sample size and designing appropriate messages
for future HIV vaccine efficacy trials. The study objective was to determine
incidence and risk factors for HIV transmission.
Methods: Approximately 1200 adults (18-60 years) were enrolled into
a 24-month study. Education about the study, HIV voluntary testing and
counselling and medical evaluations are done at enrolment and 3 monthly. HIV
comprehension and risk factor data are collected 6 monthly. Medical care is
provided and referrals made as needed.
Results: A total of 14 incident cases (7 males; 7 females) have been observed
in 1028 person-years (incidence: 1.4% [95% CI 0.8-2.2]). The incidence
among those below 45 years was 1.7% (95% CI 1.0-2.8) with a total of 825
person-years. There were no seroconversions in persons older than 44 years.
The mean age among seroconverters was 32 years (range 23-44), 9 were
married (1 was in an HIV discordant relationship), 2 were single, 2 were
divorced and 1 was in a steady relationship. Of the 14, 3 individuals reported
having a casual sexual partner and 4 reported condom use in past 1 year.
History of sexually transmitted infections (STIs) at study entry was common:
genital ulcer disease (5), urethral discharge (5) and vaginal discharge (1). 12
considered themselves at risk of HIV infection at study entry, 8 because their
partner was unfaithful and 2 because they were unfaithful. Rate ratios are not
computed because of the relatively small number of incident cases for each
risk factor.
Conclusions: These findings suggest that young people (<45 years) would be
more suitable for the planned vaccine efficacy trials in this general population.
HIV risk perception and history of STIs could be useful factors in screening for
high-risk population.

XVI INTERNATIONAL AIDS CONFERENCE * 13-18 AUGUST 2006 * TORONTO CANADA * ABSTRACT BOOK VOLUME 1