Soil-transmitted helminth infections and intestinal and systemic inflammation in schoolchildren

The objective of this study was to assess whether soil-transmitted helminth (STH) infections are associated with systemic and local intestinal inflammation in school-age children. In two studies in schoolchildren in Cuba (N = 1389) and in Cambodia (N = 2471), STH infections and calprotectin concentrations were measured in stool samples and acute phase proteins C-reactive protein (CRP) and alpha-1 acid glycoprotein (AGP) were measured in blood. Associations between STH infections and elevated concentrations of CRP, AGP and calprotectin were estimated using multiple logistic regression. The prevalence of elevated CRP concentration (≥5 mg/L) was 5.4% in both populations. Elevated AGP (≥1 g/L) was found in 39.5% of the Cambodian children and 11.3% of the Cuban children. Fecal calprotectin was elevated (≥50 mg/kg) in 9.4% of the Cambodian children and 3.7% of the Cuban children. STH infections in Cuba were mainly due to Ascaris lumbricoides and Trichuris trichiura, with prevalences of 5.2% and 3.2%, respectively. In Cambodia, hookworm was the most prevalent species (16.3%). We found no significant associations between elevated concentrations of either acute phase proteins or fecal calprotectin and STH infections. We observed a trend towards an inverse association between elevated CRP and STH infections in both studies. STH infections are not associated with either local intestinal or systemic inflammation. The trend towards less elevated CRP concentration in STH infections may indicate a reduced risk of metabolic inflammatory diseases, which merits further investigation.