Helminth parasites, a major factor in malnutrition

Abstract

The author discusses the significance of helminth and schistosome infections in exacerbating nutritional problems in many countries, and advocates population-wide treatment where there is clear evidence that this would yield substantial gains in the quality of life.

PIP: Helminth and schistosome infections occur in the same geographical areas as does malnutrition. These parasitic infections can occur already in malnourished persons. Hookworm infections reduces food intake and/or increase nutrient wastage via vomiting, diarrhea, or blood loss. These effects exasperate protein energy malnutrition, anemia, and other nutrient deficiencies. Hookworm infection reduces the work capacity and productivity of children and adults; increases maternal and fetal morbidity, premature delivery, and low birth weight, as well as the susceptibility to other infections; and reduces the rate of cognitive development. These social and economic consequences in turn reduce the ability of people and families to raise crops or earn enough money to buy food and other essentials. As many as 90% of the children in some areas of the developed world are infected with roundworm. More than 100,000 deaths in 1987 resulted from complications of roundworm infection (e.g., intestinal obstruction). Roundworm infection reduces the body's ability to use protein and to absorb fat, which worsens protein energy malnutrition. Other nutrient effects of roundworm infection are exacerbation of vitamin A deficiency and lactose and milk intolerance. Whipworm infection can effect prolapse of the rectum and nutritional problems. Treatment of children with whipworm improves hematocrit, growth rates and anthropometry, and serum albumin, and reduces diarrhea and bacterial and protozoan infections in the bowel. Schistosomiasis causes nutritional effects similar to those of helminths. Studies in Kenya show that, in children, 1 treatment against worm, infections improves growth and fitness within 4 months. Other studies in Kenya show that treating children for worms or anemia improves weight gains per month at least as much as and usually more than school feeding programs, a more labor intensive, complicated, and expensive effort. Deworming programs should operate in areas where undernutrition exceeds 25% and worms are prevalent.