Objectives: To determine the potential for secondary HIV transmission among newly HIV-infected men who have sex with men (MSM) during their HIV antibody seroconversion period, and for the 12 months after seroconversion.
Design: A cohort study.
Methods: Risk assessment questionnaires administered before receipt of the first positive HIV antibody result, plasma and seminal viral load measurements, and risk assessments one month and quarterly after receipt of the first HIV-positive test, and generalized estimating equation modelling techniques to analyse behavioral trends.
Results: Of 66 seroconverters, more than half reported unprotected anal intercourse (UAI) with HIV-negative or unknown-serostatus partners during seroconversion, with 27% reporting insertive UAI with an HIV-negative partner. The initial median plasma viral load was 4.6 log/ml, the median seminal viral load was 2.7 log/ml, suggesting a high level of infectiousness. Compared with risk behavior during seroconversion, UAI with HIV-negative or unknown-serostatus partners was reduced after the receipt of positive antibody results; however, a substantial proportion of participants reported high-risk behaviors for transmission for 12 months of follow-up. After learning of their HIV infection, recent seroconverters did not reduce the risk of secondary transmission by engaging in proportionally more high-risk practices with HIV-infected partners (compared with HIV-negative or unknown-serostatus partners), or engaging in proportionally more receptive compared with insertive UAI.
Conclusion: Substantial potential exists for secondary HIV transmission during and for one year after HIV seroconversion. Receipt of an HIV-positive test is associated with a significant reduction in risk behavior, reinforcing the need to identify and counsel recently HIV-infected MSM.