The "malnutrition-infection" complex, the most widespread public health problem in underprivileged populations.

The synergistic association between malnutrition and infection remains today the most worrisome public health problem in the world. Although the high level of mortality among children in developing countries is mainly due to infectious and parasitic diseases, more than half of these children die in a state of overt undernourishment. Energy and nutrient deficiencies adversely affect various aspects of immunocompetence, thus malnourished people are particularly sensitive to many opportunistic infections. These, in turn, induce anorexia, various metabolic changes and malabsorption, which affect nutritional reserves, and lead to malnutrition if prolonged. In the absence of efficient measures to break this vicious cycle, malnutrition and morbidity lead to high levels of mortality. Experience from developing countries suggests that to improve the prevention and treatment of infectious diseases in such a context of poverty, one need to take into account simultaneously the basic environment of underprivileged groups and their dietary intake as well as their level of access to health care services.