Impact of antiretroviral therapy on HIV-1 transmission dynamics

D. Bezemer

The first AIDS cases in the Netherlands were diagnosed in 1982 among men having sex with men (MSM). In 1984 serological testing was possible and from 1991 antiretroviral mono therapy was available. However resistant strains emerged within several weeks on therapy, and were also shown to be transmitted. Since 1996 effective combination antiretroviral therapy (cART) is available. cART proved effective as morbidity and mortality among HIV infected patients strongly decreased. cART reduces the viral load and therewith also the infectiousness. However annual HIV-1 diagnoses among MSM have been increasing over the past decade. We wanted to know the impact that cART has had on the transmission dynamics of HIV-1 among MSM. For this we used data till 2007 from the prospective Amsterdam Cohort Studies and 24 HIV treatment centres in the Netherlands as part of the ATHENA national observational cohort. In conclusion there is a resurgent epidemic amongst MSM. Increasing risk-behaviour has offset the benefits of cART in reducing HIV transmission in The Netherlands. HIV-1 among