Potential of community-wide chemotherapy or immunotherapy to control the spread of HIV-1

Abstract

WHETHER zidovudine (3′-azido-3′-deoxythymidine, AZT) should be offered to symptomless individuals infected with human immunodeficiency virus type-1 (HIV-1), in the hope of delaying or even preventing progression to AIDS, has been much debated¹. The discussion has focused on the efficacy of the drug in delaying progression to disease², the severity of its side-effects³, and the likelihood of its prolonged and widespread use resulting in zidovudine-resistant strains of the virus⁴. Little attention has been given to the degree to which treatment reduces the infectiousness of symptomless patients, and to the concomitant implications for the overall transmission rate of HIV-1 in the community. Here we use simple mathematical models to show that community treat-ment with antiviral drugs or immunotherapies that lengthen the incubation period of AIDS without significantly reducing the infectiousness of treated individuals, can increase the rate at which HIV-1 infection spreads (which is fairly obvious) and can even, under certain circumstances, increase the AIDS-related death rate in the community (which is less obvious).