Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 12/2/1999
Publication Date: N/A
Interpretive Summary: International students and travelers, migrant laborers, refugees, children of foreign adoptions and the homeless are groups in the United States that are at risk for intestinal nematode infections. Symptoms of these infections are often minimal or vague, yet many such infections carry significant long-term morbidity such as poor growth, reduced cognitiive development, and secondary microbial disease. Intestinal nematodiasis has long been recognized as a significant cause of disease, wasting, and stunting in humans and animals. Multiple mechanisms contribute to suboptimal acquisition and utilization of nutrients. Studies in animal models have focused on the mechanisms contributing to nutrient under-utilization. Mammals respond to nematode parasites in the intestine with a stereotypical immune response pattern. However, the immune response has a nutritional cost to the host, and is sometimes associated with immune epathology. Understanding the basic mechanisms of protective immunity to these parasites while limiting the negative effects of the immune system will provide better ways of managing these problems in both humans and livestock. This report provides current views on the important nematodes that infect humans and livestock and describe the future role that immunity will play in integrated control strategies.
Technical Abstract: One billion people are infected with intestinal nematodes worldwide, and several million of them are symptomatic. Ascaris lumbricoides, hookworms, and Trichuris trichiura are the most commonly diagnosed gastrointestinal nematodes associated with intestinal disease. Children are more likely to be diagnosed with intestinal nematode infections than adults, which correlates with acquired resistance to these parasites. Current data demonstrate that intestinal nematode infections in children are associated with decreased appetite, growth suppression, and cognitive disorders. Symptoms are often minimal or vague, yet many such infections carry significant long-term morbidity such as poor growth, reduced cognitive development, and secondary microbial diseases. Disagreement exists as to whether anthelmintic treatment is uniformly efficacious in improving growth and performance of infected children. Integrated control strategies enhance chances for reducing parasite disease. Understanding the interaction between nematode parasites and the immune system could provide answers to the control of the morbidity and mortality associated with these infections in both humans and livestock worldwide.