The advent of Highly Active Antiretroviral Therapy (HAART) in the late90s has transformed HIV infection from a deadly condition into a chronic,manageable viral infection in developed countries [1]. The developingworld, however, accounts for 96% of the global HIV-l infections, and inmost of these countries, antiretrovirals are not yet widely available. Thenumber of persons living with Human Immuno-Deficiency Virus (HIV)infection and Acquired Immuno-deficiency Syndrome (AIDS) worldwidehas been estimated to be approximately 40 million [2], and this figureincludes approximately 5 million people who acquired HIV in 2004. In thesame period, approximately 3.1 million adults and children died from AIDS,and 14,000 new individuals are still infected daily, a number that lessenshopes for a rapid solution to this pandemic [2]. The gap between developedand developing countries in the control of the pandemic and treatment ofinfected persons is growing, and one of the factors fueling the epidemic inpoor countries is malnufrition. Moreover, protein-energy malnutrition(PEM), and the accompanying and aggravating micronufrient deficiencies,are already an overwhelming health problem and still the main cause forimmune disturbances in poor countries [3,4]. Sub-Saharan Africa, where thegreatest growth in severe and generalized malnutrition has occurred in thelast two decades [5], is also the region in which 12 out of 44 countries havemore than 10% prevalence of HIV in the adult population [6]. Numerousstudies have demonstrated that nutritional deficiencies accelerate HIVdisease progression and decrease survival [7-16]. Moreover, nutrient deficitsinterfere with the effectiveness of antiretrovirals by delaying therecuperation of the immune system and aggravating side-effects attributed totreatment [17-20]. Selenium appears to have a multifactorial role in HIV-l infection.Selenium status affects HIV disease progression and mortality [14-16]through various potential mechanisms. In two recent studies, deficiency ofselenium has been associated with elevated measures of HIV infectivity[21,22], and therefore, with increased potential to transfer the infection. Selenium is required for the function of gluthatione peroxidase, a biologicalantioxidant that protects against oxidative stress. Other selenoproteins mayalso act as antioxidants by the incorporation of selenocysteine in theirmolecules [23]. In HIV-infected persons, dietary selenium intake wasstrongly associated with reduced measures of oxidative stress [24].Adequate selenium status may also be essential for controlling viralemergence and evolution [25,26]. In addition, selenium may enhanceresistance to infection through modulation of both cellular and humoralimmunity. Plasma selenium levels are associated with interleukin productionand subsequent changes in Thl/Th2 cytokine responses [27,28]. Othernutritional factors interact with selenium status and are important in HIV-1disease progression and mortality. These factors include disease stage,nutritional status at the onset of the disease, types of treatment andcompliance, and secondary infections that may act independently or incombination. Treatment of malnutrition, and the accompanyingmicronutrient deficiencies, thus, requires a carefully individualizedapproach. This chapter will review the role of selenium in HFV-l diseaseprogression, morbidity and mortality, as well as the factors that may affectthese relationships.
