Abstract Book Vol. 2 [International Conference on AIDS (14th: 2002: Barcelona, Spain)]

XIV International AIDS Conference

Abstracts ThOrD1431-ThOrD1451 491

ThOrD1 431 Strategic approaches to preventing HIV infections
in infants: balancing priorities in different settings
I. de Zoysa1, M. Sweat2, G. Schmid1, K. O'Reilly1, J. Denison2. 1World Health
Organization, Department of HIV/AIDS, World Health Organization, Avenue
Appia 20, 1211 Geneva 27, Switzerland; 2The Johns Hopkins University,
Baltimore, United States
Background: WHO advocates a 3-prong strategy to reduce mother to child HIV
transmission: (1) preventing HIV among women, especially young women (2) preventing unintended pregnancies in HIV-infected women, and (3) preventing transmission from an HIV-infected woman to her infant. Nevirapine (NVP) has been
shown to be highly effective in preventing MTC HIV transmission and has gained
significant attention and donor support. The ideal balance between these approaches is being debated, but often in the absence of empirical analysis.
Methods: Using data from demonstration projects conducted by UNICEF, and behavioral, cost, and demographic data we estimated the cost-effectiveness of NVP
in African countries using a stochastic model. Multiple scenarios are calculated
to examine variation in cost, uptake, and biologic parameters. Threshold analysis
is used to calculate the reduction in adult HIV prevalence that would result in an
equivalent reduction in infant HIV infection. Uganda results are presented here,
which are illustrative of our analyses.
Results: In our lowest cost scenario a nationwide NVP program would cost $5.9M
(USD) per/year and avert 1404 infant HIV infections. If HIV prevalence among antenatal women could be lowered from 8.9% to only 7.9% there would be an equivalent reduction in infant HIV infections as the NVP program, but also a reduction
of 93,111 adult infections.
Conclusions: Primary prevention to reduce adult HIV prevalence has significant
impacts on the rate of MTC transmission of HIV, and should be a core component
of PMTCT programs to prevent HIV infection in infants.
Presenting author: Isabelle de Zoysa, Department of HIV/AIDS, World Health
Organization, Avenue Appia 20, 1211 Geneva 27, Switzerland, Tel.: [phone]
3377, Fax: [phone], E-mail: [email protected]
ThOrD1449 Prevalence of unsafe sex practices among
HIV-infected individuals: The Swiss HIV Cohort
Study (SHCS)
K. Wolf, J. Young', P Taffe2, M. Flepp3, H.J. Furrer4, A. Telenti 5, B. Hirschel6,
P. Vernazza7, E. Bernasconi8, M. Rickenbach9, H.C. Bucher1~. 'Basel Institute
for Clinical Epidemiology, Basel Institute for Clinical Epidemiology, University
Hospital Bael, Kantonsspital Basel, CH-4031 Basel, Switzerland; 2Swiss HIV
Cohort Data Center, Centre Hospitalier Universitaire Vaudois, Lausanne,
Switzerland; 3Division of Infectious Diseases and Hospital Epidemiology,
University Hospital Zurich, Zurich, Switzerland; 4 Division of Infectious Diseases,
Inselspital, Berne, Switzerland; 5 Divison of Infectious Diseases, Centre
Hospitalier Universitaire de Lausanne, Lausanne, Switzerland; 6Division of
Infectious Diseases, University Hospital Geneva, Geneva, Switzerland;
7Infectious Disease Unit, Cantonal Hospital St Gall, St. Gall, Switzerland;
8nfectious Disease Unit, Ospedale Regionale, Lugano, Lugano, Switzerland;
9Swiss HIV Cohort Data Center, Centre Hosptialier Universitaire Vaudois,
Lausanne, Switzerland; 1oBasel Institute for Clinical Epidemology Basel,
Switzerland
Background: Sexual contact is the major mode of HIV transmission worldwide.
Increased sexual risk taking has been reported in HIV-infected patients receiving
highly active antiretroviral therapy.
Methods: We evaluated the sexual risk behaviour of individuals in the SHCS in
relation to antiretroviral therapy (ART), response to therapy, risk group for HIV
transmission, age, gender, HIV-status of partner, ethnicity, education and type of
partnership (stable or occasional). On 1 April 2000 a questionnaire about safer
sex practices was introduced into the SHCS. We included all individuals who
completed this questionnaire for the first time during the following year.
Results: On 1 April 2000, 5758 individuals wa riers r ased with the SHS, and
5286 individuals (92%) responded to the questionnaire. The percentage of females, younger individuals, IV drug users, Caucasians and those with a basic
education was higher among non-responders than among responders. Overall
14% reported unsafe sex, 73% received ART and 22% had good viral suppression (HIV RNA always < 50 copies/mI during the preceding 12 months). Among
those who responded,, 20%i caassiaal partners, anV dasion p, ang
6% both. Of the individuals with stable partners, 82% reported sexual intercourse
and of those reporting sexual intercourse, 73% always used condoms. Of the individuals with occasional partners, 98% reported sexual intercourse and of those
reporting sexual intercourse, 82% always used condoms. After adjustment for
other covariates, reported unsafe sex was not associated with good viral suppression (OR: 0.96, 95% Cl: 0.76 - 1.22). Reported unsafe sex was associated
with gender, age, ethnicity, H
V-status of partner, having occasional partners, HIV transmission group, living
alone and ART, but not with education.
Conclusion: There is no evidence that good viral suppression leads to unsafe

sex among individuals of the SHCS. However, other factors are associated with
unsafe sex.
Presenting author: Jim Young, Basel Institute for Clinical Epidemiology, University Hospital Bael, Kantonsspital Basel, CH-4031 Basel, Switzerland, Tel.: [phone], Fax: [phone], E-mail: [email protected]

ThOrD 450 High risk sexual behaviour increases among
London gay men between 1998-2001: what is the
role of HIV optimism?
J. Elford1, G. Bolding 2, L. Sherr2. 1City University, London, United Kingdom;
2Royal Free & UC Medical School, London, United Kingdom
Background: To examine whether HIV optimism (ie optimism in the light of new
HIV drug therapies) can account for the recent increase in high risk sexual behaviour among gay men in London.
Methods: Gay men (n=2938) using central London gyms were asked to complete
anonymous self-administered questionnnaires in 1998, 1999, 2000 and 2001. At
each time point information was collected on HIV status, unprotected anal intercourse (UAI) in the previous 3 months and agreement/disagreement with two
optimism statements concerning (a) severity of, and (b) ulnerability to infection
with HIV. Those who agreed were classified as "optimistic".
Results: Between 1998-2001 the percentage of men reporting high risk UAI (ie
UAI with a casual partner of unknown or discordant HIV status) increased: HIV
positive men, 15.3% to 38.8%; HIV negative men 6.8%, 12.1%; never-tested men
2.1%, 7.7% (p<0.01). Overall less than a third of the men were classified as
optimistic. In cross-sectional analysis, optimistic HIV positive and negative men
(but not the never-tested) were more likely to report high risk UAI than other men
(p<0.05). However, the increase in high risk UAI between 1998-2001 was seen
in both those who were optimistic (the minority) and those who were not (the
majority) (p<0.05). In a multivariate model, the increase in high risk UAI over
time remained significant after controlling for HIV optimism (all men, odds ratio
1.54 per year, 95% Cl 1.14, 2.05, p<0.01). There was no significant interaction
between optimism and time although for HIV positive men this was borderline
(p=0.07).
Conclusion: Among London gay men, the increase in high risk sexual behaviour
between 1998-2001 was statistically independent of HIV optimism. The modelled
increase in high risk UAI was seen equally in those who were optimistic and those
who were not. This provides evidence that HIV optimism alone can not explain the
recent increase in high risk sexual behaviour among London gay men.
Presenting author: Jonathan Elford, City University, 20 Bartholomew Close, London EC1A 7QN, United Kingdom, Tel.: [phone], Fax: +44 (0) 20
7040 5717, E-mail: [email protected]
ThOrD1451 Sexual behaviors and condom use among people
living with HIV/AIDS (PLWHIV) in Chile
X. Sgombich1, Y. Souteyrand2, N. Damianovic1, A. Arredondo3, V. Dor2,
A. Henriquez4, and the Chilean Drug Access Initiative ANRS Study Group4.
I NOUS Investigacion & Asesoria, Chile; 2ANRS, Paris, France; 3CONASIDA,
Santiago de Chile, Chile; 4ANRS, Santiago de Chile, Chile
Background: Since 1997 Chile has been scaling up access to antiretroviral multitherapies (ARV). Impact of enlarging access to treatment on preventive behaviors
is a major issue. We compare sexual and preventive behaviors of people treated
(PWT) and untreated (PNT) with ARV.
Methods: A random sample of 800 PLWHIV (161 women, 639 men including 435
MSMs), followed up by the Chilean Public Health System have been interviewed
face to face between 12/00 and 02/01. Data on sexual behaviors, partnership,
condom use and disclosure of serological status to sexual partners have been
collected.
Results: In the last 12 months before the interview, 553 persons (69%) were
sexually active. PWTs (n=548) are less often sexually active than PNTs (n=247)
(65.5% vs 76.9%, p=0.002) and they have had less frequently more than one partner (16.2 vs 22.2% p=3.3, NS). The frequency of sexual relationships is lower for
PWTs than for PNTs (more than once a week: 43 % vs 53%, p=0.03). The consistent condom use is higher among PWTs than among PNTs, significantly for the
multipartners (use of condom in each sexual intercourse: 92 vs 69%, p=0.01).
Disclosure of serostatus to the regular partner is not significantly different between PWTs and PNTs (84 vs 80%, p=0.2). The proportion of PWTs who report
a reduction of the frequency of sexual relationships since the initiation of treatment is higher than those reporting an increase: 50.4 vs 7.8% for monopartners;
43.8 vs 5.62% for multipartners.
Conclusion: In Chile, PWTs are more often sexually abstinent in the last 12
months than PNTs. They report less sexual relationships and use condoms more
consistently. Further analysis is necessary to identify clinical (impact of disease
severity and treatment on sexuality) and behavioral determinants (awareness of
the risks of infection). However it appears clearly that the enlargement of access
to ARV does not by itself increase at-risk behaviors among PLWHIV.
Presenting author: yves souteyrand, ANRS, 101 rue de Tolbiac, 75013,
Paris, France, Tel.: [phone], Fax: [phone], E-mail: yves.souteyrand
@ anrs.fr

ThOrD 452 Sexual behaviours among HIV infected patients in
the context of the drug access initiative in Cote
d'lvoire
J. Prudhomme', P. Msellati2, M. Souville3, J.P. Moatti3. Observatoire regional
de la sante, Marseille, France; 2IRD/LPE, INSERM U79, 232 Bd Ste Marguerite,
13009 Marseille, France; 3INSERM U379, Marseille, France
Background: Few data are available in Africa on the impact of antiretroviral treat