Childhood parasitic infections and gastrointestinal illness in indigenous communities at Lake Atitlán, Guatemala.

Lake Atitlán has experienced a decline in water quality resulting from cultural eutrophication. Indigenous Mayans who already face disproportionate health challenges rely directly on the lake water. Our objectives were to: (1) estimate prevalence of shedding of water-borne fecal parasites among children 5 years of age and younger, (2) assess household-reported incidence of gastrointestinal illness in children, and (3) characterize water sources, treatment, and sanitation conditions in households. We hypothesized that household use of untreated lake water results in increased risk of shedding of parasites and gastrointestinal symptoms. A cross-sectional fecal sampling and physical exam of 401 children were conducted along with WASH surveys in partnership with healthcare providers in seven communities. Fecal samples were screened for Giardia lamblia and Cryptosporidium parvum, using a rapid ELISA, with a portion examined by microscope. The prevalence of parasite shedding was 12.2% (9.7% for Giardia; 2.5% for Cryptosporidium). Risk factors for Giardia shedding included age 3 years or older (3.4 odds ratio, z-stat = 2.781 p = 0.0054), low height-for-age z-score (2.3 odds ratio, z-stat = 2.225, p = 0.0216), lack of any household water treatment (2.5 odds ratio, z-stat = 2.492, p < 0.0012), and open access to household latrine (2.04 odds ratio, z-stat = 1.992, p = 0.0464). The majority (77.3%) of households reported water treatment, boiling and gravity fed filters as the most widespread practices. The vast majority of households (92%) reported usage of a latrine, while 40% reported open and shared access beyond their household. An overwhelming majority of households reported diarrhea and fever several times per year or greater, with approximately half reporting vomiting at that frequency. Lake water use was identified as a risk factor for households reporting frequent gastrointestinal symptoms (odds ratio of 2.5, 4.4, and 2.6; z-stat of 3.10, 3.65, and 3.0; p-values of 0.0021, 0.0003, and 0.0028, for diarrhea, vomiting, and fever, respectively) in children 5 years of age and younger. The frequency of gastrointestinal illness with a strong link to lake drinking water cannot be explained by the prevalence of protozoa, and risk from other enteropathogens must be explored. Improving access to water treatment and sanitation practices could substantially reduce the parasite burden faced by developing children in the region.

Micronutrient supplementation of lactating Guatemalan women acutely increases infants' intake of riboflavin, thiamin, pyridoxal, and cobalamin, but not niacin, in a randomized crossover trial.

BACKGROUND: Maternal supplementation during lactation could increase milk B-vitamin concentrations, but little is known about the kinetics of milk vitamin responses. OBJECTIVES: We compared acute effects of maternal lipid-based nutrient supplement (LNS) consumption (n = 22 nutrients, 175%-212% of the RDA intake for the nutrients examined), as a single dose or at spaced intervals during 8 h, on milk concentrations and infant intake from milk of B-vitamins. METHODS: This randomized crossover trial in Quetzaltenango, Guatemala included 26 mother-infant dyads 4-6 mo postpartum who were randomly assigned to receive 3 treatments in a random order: bolus 30-g dose of LNS (Bolus); 3 × 10-g doses of LNS (Divided); and no LNS (Control), with control meals. Mothers attended three 8-h visits during which infant milk consumption was measured and milk samples were collected at every feed. Infant intake was assessed as $\mathop \sum \nolimits_{i\ = \ 1}^n ( {{\rm{milk\ volum}}{{\rm{e}}_{{\rm{feed\ }}n}} \times \ {\rm{nutrient\ concentratio}}{{\rm{n}}_{{\rm{feed}}\ n}}} )$ over 8 h. RESULTS: Maternal supplementation with the Bolus or Divided dose increased least-squares mean (95% CI) milk and infant intakes of riboflavin [milk: Bolus: 154.4 (138.2, 172.5) µg · min-1 · mL-1; Control: 84.5 (75.8, 94.3) µg · min-1 · mL-1; infant: Bolus: 64.5 (56.1, 74.3) µg; Control: 34.5 (30.0, 39.6) µg], thiamin [milk: Bolus: 10.9 (10.1, 11.7) µg · min-1 · mL-1; Control: 7.7 (7.2, 8.3) µg · min-1 · mL-1; infant: Bolus: 5.1 (4.4, 6.0) µg; Control: 3.4 (2.9, 4.0) µg], and pyridoxal [milk: Bolus: 90.5 (82.8, 98.9) µg · min-1 · mL-1; Control: 60.8 (55.8, 66.3) µg · min-1 · mL-1; infant: Bolus: 39.4 (33.5, 46.4) µg; Control: 25.0 (21.4, 29.2) µg] (all P < 0.001). Only the Bolus dose increased cobalamin in milk [Bolus: 0.054 (0.047, 0.061) µg · min-1 · mL-1; Control: 0.041 (0.035, 0.048) µg · min-1 · mL-1, P = 0.039] and infant cobalamin intake [Bolus: 0.023 (0.020, 0.027) µg; Control: 0.015 (0.013, 0.018) µg, P = 0.001] compared with Control. Niacin was unaffected. CONCLUSIONS: Maternal supplementation with LNS as a Bolus or Divided dose was similarly effective at increasing milk riboflavin, thiamin, and pyridoxal and infant intakes, whereas only the Bolus dose increased cobalamin. Niacin was unaffected in 8 h. This trial was registered at clinicaltrials.gov as NCT02464111.

Efficient purification of arsenic-contaminated water using amyloid-carbon hybrid membranes.

We show the purification of arsenic-contaminated water using amyloid fibril-based membranes, which adsorb both the arsenate (+5) and arsenite (+3) oxidation forms at efficiencies of ∼99%. Binding isotherms indicate that amyloid fibrils possess multiple binding residues capable of strongly adsorbing arsenic ions via metal-ligand interactions, delaying the saturation of the membrane. We also show that these membranes can be reused for several cycles without any efficiency drop, and validate our technology in purifying real contaminated ground water by removing arsenic with an efficiency as high as 99.6%. These results make this technology promising for inexpensive, efficient and low-energy removal of arsenic from contaminated water.

Response of urinary biomarkers of systemic oxidation to oral iron supplementation in healthy men.

BACKGROUND: Urinary biomarkers are used in assessment of severe, clinical oxidative stress. Little is known, however, about their diagnostic value within the normative range. OBJECTIVE: To evaluate the response of urinary thiobarbituric acid reactive substances (TBARS) and 8-hydroxy-2-deoxyguanosine (8-OHdG) as indicators of systemic oxidation in response to short-term oral iron and antioxidant supplementation. METHODS: Five healthy adult men participated in the pilot study phase and 12 in the definitive intervention trial. For 7 days each, separated by 12-day washouts, the subjects received different treatment regimens, consisting of 120 mg of iron, 120 mg of iron in refined palm oil, and 120 mg of iron in palm oil combined with one of the two doses of Carotino Tocotrienol Carotene Mixed Concentrate (CTCMC). Creatinine-normalized urinary TBARS and 8-OHdG concentrations were quantified in samples taken from subjects with and without active supplementation. Temporal and correlative associations between TBARS and 8-OHdG were explored. RESULTS: Daily intake of supplemental iron failed to produce any increment in urinary excretion of TBARS or 8-OHdG. However, a significant within-individual correlation between the urinary biomarkers was observed (Spearman r = 0.697, p < .0001, n = 466). Both doses of CTCMC significantly lowered urinary excretion of both oxidation indicators. CONCLUSIONS: Despite the lack of effect of oral iron on the biomarkers of systemic oxidation, they show a strong and significant mutual association within the nonpathological range of oxidative stress in healthy male adults.

Equivalent effects on fecal reactive oxygen species generation with oral supplementation of three iron compounds: ferrous sulfate, sodium iron EDTA and iron polymaltose.

BACKGROUND: In any context of iron supplementation in the prenatal prophylaxis or therapeutic dosage range, a large amount will remain unabsorbed and pass through the intestinal tract into the colonic digesta possibly causing increased oxidation. AIM: To compare the generation of fecal reactive oxygen species (ROS) in situ after daily consumption of 100 mg of elemental iron in three frequently used forms of iron supplements. METHODS: Ten healthy, iron-repleted adult males were investigated before and during supplementation with three oral iron compounds: 100 mg of oral iron were given as ferrous sulfate, Na Fe-EDTA and iron polymaltose for 6 days to each subject in an individually stratified sequence. Stool samples were collected and analyzed for iron content and the in situ generation of fecal ROS. RESULTS: Significant increases in fecal ROS generation were observed during oral iron supplementation. No statistical differences were seen in either residual concentrations of non-heme iron in stool or the level of fecal ROS generation between the three Fe compounds. There was, however, a significant association between the iron concentration in the stool and ROS generation. CONCLUSION: In spite of the differences in their chemical characteristics, none of the three distinct iron complexes reduced oxidative stress in the intestinal lumen.

Antioxidant-rich oral supplements attenuate the effects of oral iron on in situ oxidation susceptibility of human feces.

Prophylactic doses of 120 mg of iron (Fe) are commonly used to prevent Fe-deficiency anemia in vulnerable populations, especially in developing countries. Evidence shows that residual Fe in the large bowel may alter the normal antioxidant capacity of the fecal stream. Our objective was to evaluate the effect of dietary antioxidants from the Carotino Tocotrienol-Carotene Mixed Concentrate (CTCMC) on the depletion of fecal antioxidant capacity by oral Fe supplementation. In total, 17 healthy male adults participated in the 2 phases of the study, 5 in the pilot study and 12 in the definitive intervention trial. Participants received different treatments, separated by washout periods. These included: 120 mg Fe; 120 mg Fe and refined palm oil (FeOil); and 120 mg Fe in refined palm oil combined with 1 of 2 dosages (0.4 g and 0.8 g) of CTCMC/5 mL of refined palm oil (CTCB and CTCA treatments, respectively). Fecal samples were collected and analyzed to quantify the products of hydroxyl radical attack on salicylic acid (2,5 dihydroxybenzoic acid, 2,3-dihydrobenzoic acid, and catechol) at baseline and after active supplementation. Fe supplementation in either form (Fe or FeOil treatments) increased the concentrations of hydroxylated compounds in fecal samples. The production of hydroxylated compounds was significantly lower in treatments CTCB and CTCA than in the FeOil reference. Baseline antioxidant capacity state was virtually restored with dietary carotenoids and tocotrienols from the CTCMC. In conclusion, dietary antioxidants can reverse the depletion of fecal antioxidant capacity induced by oral Fe supplements.