Debate on the paper

Since the classic papers by Sir Ronald Ross, the need to consider phenomena from both the individual and collective perspectives at the same time has been key to understanding the dynamic of infectious diseases. Unfortunately, this double dimension of the epidemiology of infectious diseases has been too often disregarded/misinterpreted. In their paper, Vlahov & Celentano revive the challenge posed by the epidemiology of infectious diseases (specifically HIV/AIDS) in its interface with key ethical aspects informing health policies targeting drug users. There is a double ethical and scientific imperative to be addressed here: to treat individual drug-dependent patients and to assess comprehensively the impact of anti-retroviral therapy on the quality of life, morbidity, and mortality of individual patients; and, at the same time, to evaluate carefully the putative impact of instituting such regimens within the population of drug users at large, their partners, their offspring and the general public. As time passed, the scope of highly active anti-retroviral therapy (HAART) moved from a small pocket of affluent patients, most of them engaged in programs of expanded access to the then new protease inhibitors and drug combinations, to a relatively larger number of patients. The new therapeutic alternatives then faced their first challenge: instead of carefully controlled phase III clinical trials, treating “real world” patients with less than optimal adherence, inexperienced physicians, deficiencies in the infra-structure of many facilities, etc. The approval, in 1996, of the Brazilian federal law guaranteeing ample and free access to ARV therapy for people living with HIV/AIDS represented a breakthrough but created a new layer of complexity to the management of people living with HIV/AIDS, worldwide. First of all, how would a developing country be able to fund and manage such an initiative for a sizeable population of people living with HIV/AIDS, facing serious side-effects and demanding careful monitoring on a continuous basis. Some critics predicted that the Brazilian program was doomed to failure. It was feared by many that such an attempt would be suboptimal and would not only jeopardize individuals but would also have side effects at the ecological level by putatively creating a “Petri dish” where resistant viruses would breed. Although such catastrophic forecasts have not materialized and Brazil has reported adherence and resistance levels comparable to developed countries 1, similar alarms are also occasionally raised by clinicians afraid of initiating HAART for drug users and other disenfranchised populations. One may note, however, that when HAART moved from the original clinical trials to real life conditions in the developed world, such optimal conditions also did not exist. The introduction of HAART in affluent populations of the developed world was driven, at least in part, by pressures from groups of activists, and favored treatment protocols were established in correspondence with the emergence of formidable challenges in terms of defining monitoring routines and management of serious side-effects. The paper by Vlahov & Celentano is especially relevant at a time when many different agencies and governments, worldwide, are engaged in a serious effort to scale-up access to ARV therapy in developing countries. Whereas the worst situation in terms of access to therapy is by far the one found in Subsaharan Africa, where the injection of illicit drugs is not prevalent (although increasing in some specific settings), the situation is of special concern in Eastern Europe, where a sizeable population of injection drug users (IDUs) has been minimally affected by HIV and other blood-borne and sexually transmitted infections. In Eastern Europe, particularly in Russia and former USSR republics, the fast and extensive spread of HIV and other deadly viruses is framed by a disorganized health system and plagued by shortage of funds, unmotivated staff, and restrictive legislation (which, for instance, forbids the institution of methadone substitution therapies). Within this context, data obtained from impoverished and marginalized populations living in the USA and other developed countries are vital, not only in terms of managing HIV/ AIDS in those very settings but to pave the way of public policies targeting a globalized world, where problems are becoming everyday more inter-related, but demanding responses tailored to local needs and specificities. Debate on the paper by David Vlahov & David D. Celentano