Hookworm infection and intestinal blood loss

Abstract

54 patients with varying degrees of pure Necator americanus infection and iron deficiency anemia were studied to determine the relationship between hookworm and intestinal blood loss. In 5 of the patients detailed results of egg counts red cell survival and intestinal blood loss at different hemoglobin concentration levels are reported. A high correlation was found between blood loss and the number of parasites recovered but the relationship between the amount of blood loss per worm and worm load was not significant. A highly significant correlation was found between both the number of eggs per gm of feces or the number of eggs per day and fecal blood loss. Egg counts are better correlated with blood loss than total parasite counts and as expected with the total number of females. The male to female ratio was determined in 15 cases and the percentege of females ranged from 52-80%. Detailed analyses in 5 patients showed fairly consistent daily egg counts but a wider variation in fecal blood loss which was apparently not related to stool size or water content. No clear trend was observed in blood loss with increasing blood hemoglobin concentrations. When hemoglobin concentration was reduced red cell survival was abnormally low but was corrected in 4 out of 5 cases with iron treatment. Although heavily infected the toxin of the parasites did not interfere with the life span of the erythrocytes. The extent to which hookworms are responsible for iron deficiency anemia in an endemic area may be presumed from egg counts.