Drugs Alone Insufficient to Prevent HIV Transmission

Promotion of safe sexual practices in developing countries may be essential, according to predictive model

THURSDAY, March 16 (HealthDay News) -- Increasing the availability of antiretroviral therapy alone is not likely to prevent many HIV transmissions in resource-poor countries, and promotion of safe sexual practices may be essential for long-term change, British researchers report in the April issue of PLoS Medicine.

Geoff P. Garnett, Ph.D., and colleagues from Imperial College London designed a mathematical model to evaluate the impact of the anticipated scale-up of antiretroviral therapy on HIV transmission in resource-poor countries.

The researchers found that unlimited availability of antiretroviral therapy for patients with late-stage infection (AIDS) was likely to increase the prevalence of HIV infection, as these people live longer and become sexually active again.

At earlier stages of infection, the degree of HIV transmission depended on the behavior of the patient. Although increasing the coverage of antiretroviral therapy resulted in more infections averted per person-year of treatment, the absolute number of averted infections was small, the investigators found. According to the study, as the availability of antiretroviral therapy increased, the emergence of drug resistance and its risk of spreading increased.

"Our analysis found that antiretroviral therapy cannot be seen as a direct transmission prevention measure, regardless of the degree of coverage," the authors conclude. "Counseling of patients to promote safe sexual practices is essential and must aim to effect long-term change."

The study was funded by an unrestricted educational grant from GlaxoSmithKline.

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