Objective: To gain insight into the spread of HIV strains with different sensitivities to antiretroviral drugs prescribed in the Netherlands.
Design: Prospective cohort study in intravenous drug users and homosexual men.
Setting: Amsterdam, the Netherlands.
Methods: HIV negative participants in the Amsterdam cohort studies among homosexual men and intravenous drug users are tested two to three times a year for HIV antibodies. The first positive serum sample of those who seroconverted was used to determine, on the basis of the nucleotide sequence of the reverse transcriptase gene of HIV, if viruses were present with a reduced sensitivity to reverse transcriptase inhibitors.
Results: In 1996, 17 new HIV infections occurred (8 in homosexual men and 9 in intravenous drug users). In two new infections in homosexual men HIV strains with reduced sensitivity to zidovudine were present.