US researchers have reported that 31% of gay men, injecting drug users and heterosexual men and women questioned during 1998 and 1999 said that they had become less concerned about becoming infected with HIV since the advent of HAART, and 17% said they were taking fewer precautions (condom use or avoidance of needle sharing) since they heard about HAART (Lehman)
The trend was particularly strong amongst injecting drug users, who were significantly more likely to report increased risk taking, However, 65% of gay men who had become less concerned about HIV infection reported unprotected anal intercourse with a casual partner in the previous year, compared with 41% of those whose views about HIV infection remained unchanged.
Sexual risk taking is likely to be encouraged by widespread US publicity for the news that people with viral load below 1500 copies did not transmit HIV in a one year study of 90 Ugandan male-female couples.
Speaking on the first day of the Seventh Retroviruses Conference in San Francisco, Dr Thomas Quinn of Johns Hopkins University in Baltimore reported that a clear association exists between viral load level and transmission risk. Each one log increase in viral load was associated with a 2.45-fold increase in transmission risk during the course of a year. Partners of individuals with viral load above 50,000 copies were becoming infected with HIV at a rate of 23 per 100 person years, compared with an average of 12 infections per 100 person years across the whole cohort
Both Dr Quinn and a Zambian research group reported no detectable difference in the risk of transmission from men to women or from women to men, challenging the widely held view that women are at greater risk from HIV than men in African countries (Quinn; Fideli).
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Fideli U et al. Virologic determinants of heterosexual transmission in Africa. Abstract 194, Seventh Conference on Retroviruses, San Francisco, 2000.
Lehman J et al. Are at-risk populations less concerned about HIV infection in the HAART era? Abstract 198, Seventh Conference on Retroviruses, San Francisco, 2000.
Quinn T et al. Viral load and risk of heterosexual transmission of HIV-1 among sexual partners. Abstract 193, Seventh Conference on Retroviruses, San Francisco, 2000.