Interaction of nutrition and infection in clinical practice.

Resistance to infection is determined by a great many interralted factors, but one of the most significant variables is nutritional status of the host. The interaction between nutrition and infection has been described as synergistic, with malnutrition reducing resistance to infection, and infection, in turn, negatively affecting nutritional status. There are qualitative if not quantitative similarities between the evidence that has been gathered from studies of children living in vast areas of the developing countries, in which high rates of both severe malnutrition and infectious diseases are linked with high mortality rates, and evidence from studies of disadvantages children living in the United States in economically depressed migrant camps, Indian reservations, or rural and urban poverty, or children compromised by debilitating chronic diseases. Maternal nutritional status during pregnancy must receive more attention as a factor in the newborn's resistance to infection. Intrauterine malnutrition may cause impaired cellular immune function in the small-for-date infant which persists throughout the first year of life. Further research is needed to clarify this relationship. The optimal management of infections includes management or maintenance of nutritional status, and, in turn, management of nutritional deficiencies include prevention and treatment of infections.