AEGiS-15IAC: Decline in sexual transmission of HIV among heterosexual couples attributable to HAART.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

Decline in sexual transmission of HIV among heterosexual couples attributable to HAART.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. ThOrB1410)

Castilla J, del Romero J, Hernando V, Marincovich B, Garcia S, Rodriguez C
Instituto de Salud Publica, Navarra, Spain

BACKGROUND: Reduction of infectivity among individuals who receive HAART has not been fully established in sexual transmission, in spite of the important influence it could have on the course of the pandemic. We aim to assess the effectiveness of HAART in reducing heterosexual transmission of HIV.

METHODS: Case-control analysis of 386 heterosexual steady couples, of which one partner had previously been diagnosed with HIV infection (index case), and the non-index partner reported sexual relationship with the index case as the unique risk exposure. These couples were prospectively enrolled when non-index partners took their first HIV test. HIV prevalence was compared along three periods: 1991-1995 (pre-HAART), 1996-1998 (early-HAART) and 1999-2002 (late-HAART).

RESULTS: HIV prevalence among partners of index cases who had not received any antiretroviral therapy was 8.7%, while no partner was infected in couples where the index case was treated with HAART (P=0.013). In the 1999-2002 period, 48.5% of index cases received HAART. Couples who reported they had practiced unprotected coitus in the previous six months represented 57% of total during the pre-HAART period and 44% during late-HAART period (P=0.098). HIV prevalence among non-index partners declined from 10.3% during pre-HAART period to 2.0% during late-HAART (P=0.011). In the logistic regression analysis, this difference between pre-HAART and late-HAART periods was the main explanatory variable of HIV infection among non-index partners (odds ratio, 0.15; 95% CI 0.03-0.71; P=0.0166) after adjusting for length of partnership, unprotected coitus in last six months, current or former pregnancies, as well as gender, CD4 count, AIDS-defining diseases and sexually transmitted infections in the index case.

CONCLUSIONS: When HAART became widely available, a reduction of about 80% in heterosexual transmission of HIV was observed, irrespective of changes in other factors that affect transmission.

Keywords: AEGIS, HIV, Acquired Immunodeficiency Syndrome, Antiretroviral Therapy, Highly Active, Heterosexuality, HIV Seropositivity, Unsafe Sex, HIV Infections, Prevalence, CD4 Lymphocyte Count, HIV Antibodies, transmission, immunology

040711
ThOrB1410