Improving the detection of environmental enteric dysfunction: a lactulose, rhamnose assay of intestinal permeability in children aged under 5 years exposed to poor sanitation and hygiene

Background

Environmental enteric dysfunction (EED) is an asymptomatic intestinal disorder affecting populations living in conditions of poor sanitation and hygiene. The study tested intestinal barrier function in infants with EED.

Methods

We prospectively studied an advanced high-performance liquid chromatography mass spectrometry assay of urine collected after oral intake of the monosaccharide, L-rhamnose and the disaccharide, lactulose, in 112 children from three continents.

Findings

Compared to the US cohort (n=27), the cohorts of children from Peru (n=19) and Zambia (n=85) were older with evidence of growth impairment. The median (range) of age (months) was 8.0 (2.0 to 13.0), 27.0 (15.0 to 29.0) and 21.0 (12.0 to 36.0), respectively. The median (range) of height for age Z score was −0.1 (−1.8 to 2.4), −1.8 (−3.3 to −0.2) and −2.3 (−8.5 to 1.2), respectively. Among children with valid sugar data (n=22 USA, n=19 Peru, n=73 Zambia), there were no significant differences in the median rhamnose urine concentrations between the three groups. The median (range) lactulose concentration (µg/mL) was 6.78 (0.29 to 31.90), 47.60 (4.23 to 379.00) and 75.40 (0.67 to 873.00) in the US, Peruvian and Zambian cohorts, respectively (p<0.001). The lactulose/rhamnose ratio (LRR) was higher in cohorts from Peru (0.75, 0.15, 5.02) and Zambia (2.26, 0.08, 14.48) compared to the US (0.14, 0.06, 1.00) cohort (p<0.001). In a multivariate effect modification model, higher weight-for-age z scores were associated with lower post-dose lactulose when rhamnose excretion was constant (p=0.003).

Conclusions

This non-invasive two saccharide permeability protocol measures changes in intestinal permeability in children with EED and permits the identification of individuals for interventional trials.

Intestinal and systemic infection, HIV, and mortality in Zambian children with persistent diarrhea and malnutrition

BACKGROUND

Persistent diarrhea-malnutrition syndrome is a complex of infection and immune failure that involves protein, calorie and micronutrient depletion, and metabolic disturbances. We report an analysis of the impact of HIV infection on infectious disease, clinical presentation, and mortality in Zambian children with persistent diarrhea and malnutrition.

METHODS

Two hundred children (94 boys and 106 girls, 6-24 months old) were examined on admission to the malnutrition ward of University Teaching Hospital in Lusaka, Zambia. There was then 1 month of follow-up.

RESULTS

Antibodies to HIV were found in 108 of the children (54%). The common intestinal infections (Cryptosporidium parvum [26%] and nontyphoid Salmonella spp [18%]), septicemia (17%), and pulmonary tuberculosis confirmed by gastric lavage (13.5%) were not significantly more common in HIV-seropositive than in HIV-seronegative children. HIV-seropositive children were more likely to have marasmus whereas HIV-seronegative children were more likely to have kwashiorkor. Weight-for-age z scores at nadir (postedema) were lower in HIV-seropositive children (median, -4.4; interquartile range [IQR], -5.0 to -3.8) than in HIV-seronegative children (median, -3.7; IQR, -4.2 to -3.1; P < 0.0001). Height-for-age and weight-for-height z scores and mid-upper arm circumference showed a similar difference. Of the 200 children, 39 (19.5%) died within 28 days; cryptosporidiosis and marasmus were the only independent predictors of death.

CONCLUSIONS

Although intestinal and systemic infections did not differ for HIV-seropositive and HIV-seronegative children, HIV influenced nutritional states of all children. Cryptosporidiosis and marasmus were associated with higher mortality.