Species-Specific Associations Between Soil-Transmitted Helminths and Micronutrients in Vietnamese Schoolchildren

Abstract

Soil-transmitted helminth (STH) infections and micronutrient deficiencies are closely related and often coexist among low-income populations. We studied the association between infections with specific STH species and micronutrient status in rural Vietnamese schoolchildren. Children (N = 510) aged 6-9 years were recruited from two primary schools. STH infections were determined in stool samples. Hemoglobin, ferritin, retinol, and zinc were measured in blood samples, as well as C-reactive protein to control for inflammation. Iodine excretion was measured in urine. Associations of single and multiple infections with Ascaris lumbricoides, Trichuris trichiura, and hookworm with micronutrient status (hemoglobin, plasma ferritin, retinol, zinc, and urinary iodine) were estimated by multiple regression analysis. Ascaris infections showed a specific and intensity-dependent negative association with vitamin A. Trichuris and hookworm infections were associated with lower hemoglobin concentration, but not with plasma ferritin. Trichuris-infected children had zinc deficiency less often than uninfected children. In conclusion, our study shows species-specific associations between STH infections and micronutrient status in children. The different life cycles of STH species might have specific effects on the absorption or loss of specific micronutrients. Tailor-made combinations of deworming and nutritional interventions may be needed to improve child health and nutrition.

Figure 1.

Distribution of single, double, and triple soil-transmitted helminth infections among the 510 Vietnamese schoolchildren in this study population.

Figure 2.

Mean plasma retinol and prevalences of marginal and deficient vitamin A status across Ascaris infection intensity categories.