Impact of malaria and parasitic infections on human nutrition

Nearly a third of the world’s population, 2 billion people, are infected with soil-transmitted helminths, which include >270 million preschool and >600 million school-aged children [1]. Parasitic infections are widespread throughout the tropics and subtropics, particularly in developing countries where social and economic deprivation, poor hygienic conditions, malnutrition, and warm climates favor the spread of intestinal parasites. Infection with multiple parasite species (polyparasitism) also occurs not uncommonly [2]. Parasite infections contribute to malabsorption and chronic blood loss and, in children, lead to long-term effects on physical and cognitive development [3-5]. Malnutrition makes children more vulnerable to intestinal parasites, which in turn leads to even worse nutritional status, creating a synergistic relation that impairs growth and development. Young children are a particularly vulnerable subset of patients given their underdeveloped immune systems. The relation between malnutrition, infections, and altered immune status is depicted in Figure 9.1 [26]. Commonly encountered parasitic infections and potential mechanisms of nutritional impairment are shown in Table 9.1.