Antiretroviral resistance and high-risk transmission behavior among HIV-positive patients in clinical care

Background: HIV-positive patients receiving antiretroviral therapy (ART) who engage in HIV transmission behaviors may harbor and transmit drug-resistant HIV. However, little is known about the risk behaviors of these patients, potential partners exposed and the relationship of these to ART resistance. Objective: To determine the relationship of HIV drug resistance and continuing HIV transmission risk behavior among HIV-positive patients in care. Methods: A retrospective, cross-sectional study of HIV transmission risk behavior and HIV drug resistance data from 333 HIV-positive patients. Results: Among a diverse population of 333 HIV-positive patients, 75 (23%) had unprotected sex during the previous 3-months, resulting in 1126 unprotected sexual events with 191 partners of whom 155 were believed by patients to be HIV-negative or of unknown status. Eighteen of the 75 (24%) had resistant HIV and 207 unprotected sexual events, exposing 18% of the HIV- or status unknown partners. There was no difference in the proportion of patients engaging in unprotected sex who had undetectable viral load (VL) (22%): VL > 400 copies/ml without resistance (20%) and VL > 400 copies/ml with resistance (26%). Resistance and risk behavior was predicted only by lower mental health scores (odds ratio, 10.3; 95% confidence interval, 1.7-18.6). Conclusion: A substantial minority (23%) of patients in clinical care engaged in HIV sexual transmission risk behavior. A small subset of these also had ART resistant HIV. However, this core group (approximately 5% of all patients) accounted for a large number of high-risk HIV transmission events with resistant virus, exposing a substantial number of partners. (C) 2004 Lippincott Williams Wilkins.