455 research outputs found

    Effects of the Zanzibar School-Based Deworming Program on Iron Status of Children.

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    We evaluated the effects of the Zanzibar school-based deworming program on the iron status of primary school children. Parasitologic and nutritional assessments were carried out at baseline, 6 mo, and 12 mo in 4 nonprogram schools (n = 1002), 4 schools in which students received twice-yearly deworming (n = 952), and 4 schools in which students received thrice-yearly deworming (n = 970) with 500 mg generic mebendazole. Schools were randomly selected for evaluation and allocated to program groups. Relative to no treatment, thrice-yearly deworming caused significant decreases in protoporphyrin concentrations and both deworming regimens caused marginally significant increases in serum ferritin concentrations. The average annual changes in protoporphyrin concentrations were -5.9 and -23.5 micromol/mol heme in the control and thrice-yearly deworming groups, respectively (P < 0.001). The average changes in ferritin concentration were 2.8 and 4.5 microg/L, respectively (P = 0.07). Deworming had no effect on annual hemoglobin change or prevalence of anemia. However, the relative risk of severe anemia (hemoglobin < 70 g/L) was 0.77 (95% confidence limits: 0.39, 1.51) in the twice-yearly deworming group and 0.45 (0.19, 1.08) in the thrice-yearly deworming group. The effects on prevalence of high protoporphyrin values and incidence of moderate-to-severe anemia (hemoglobin < 90 g/L) were significantly greater in children with > 2000 hookworm eggs/g feces at baseline. We estimate that this deworming program prevented 1260 cases of moderate-to-severe anemia and 276 cases of severe anemia in a population of 30,000 schoolchildren in 1 y. Where hookworm is heavily endemic, deworming programs can improve iron status and prevent moderate and severe anemia, but deworming may be needed at least twice yearly

    School-Based Deworming Program Yields Small Improvement in Growth of Zanzibari School Children After one Year.

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    Efficacy trials of antihelminthic therapies conducted in Africa have reported improvements in children's growth, but nutritional evaluations of large-scale deworming programs are lacking. We evaluated the first-year effect on growth of a school-based deworming program in Zanzibar, where growth retardation occurs in school children. Children in four primary schools were given thrice-yearly mebendazole (500 mg) and compared with children in four schools that received twice-yearly mebendazole and children in four non-program schools. Evaluation schools were randomly selected and allocated to control, twice-yearly or thrice-yearly deworming. Approximately 1000 children in each program group completed the 1-y follow-up. Children <10 y old gained 0.27 kg more weight (P < 0.05) and 0.13 cm more height (P = 0.20) in the twice-yearly group, and 0. 20 kg more weight (P = 0.07) and 0.30 cm more height (P < 0.01) in the thrice-yearly group, compared with the control group. Children <10 y old with higher heights-for-age at baseline had higher weight and height gains in response to deworming. In children >/=10 y old, overall program effects on height or weight gains were not significant. But in this age range, younger boys had significant improvements in height gain with thrice-yearly deworming, and children with higher heights-for-age had greater improvements in weight gain with deworming. We conclude that the deworming program improved the growth of school children, especially children who were younger and less stunted, but the improvements were small. More effective antihelminthic regimens or additional dietary or disease control interventions may be needed to substantially improve the growth of school children in areas such as Zanzibar

    IN VITRO TOXICOLOGICAL EFFECTS OF FUMONISIN B1 ALONE AND COMBINED WITH OTHER MYCOTOXINS

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    Mycotoxins, secondary metabolites produced by moulds, mainly Aspergillus spp., Fusarium spp. and Penicillium spp., are common contaminants of food and feed. The aim of this project was to evaluate: (i) the potential endocrine disruptor effects of fumonisin B1 (FB1), beauvericin (BEA), deoxynivalenol (DON) and zearalenone (ZEA) metabolites \ufffd-zearalenol (\ufffd-ZEA) and \ufffdzearalenol (\ufffdZEA), alone and combined, using a bovine granulosa cell (GC) in vitro model and (ii) the individual and combined effects of FB1 and BEA on the intestinal barrier using Caco-2 cells cultured in vitro on semipermeable inserts. The results obtained indicated that FB1 alone at all tested doses (0; 0.5; 1; 1.5; 3; 6 \ufffdM) had no effects on GC proliferation and progesterone (P4) production. In the presence of \ufffdZEA at30 ng/mL (0.094 \ufffdM), FB1 at 30 ng/mL (0.042 \ufffdM) showed a stimulatory effect on GC numbers. Cell proliferation decreased after exposure to \ufffdZEA alone at 5.0 mg/mL (15.6 \ufffdM) and FB1 with \ufffd-ZEA and \ufffdZEA at the same concentration. Regarding steroid production, FB1 at 30 ng/mL (0.042 \ufffdM ) and 100 ng/mL (0.13 \ufffdM amplified the inhibitory effect of \ufffdZEA at 30 ng/mL (0.094 \ufffdM) on estradiol (E2) production, while FB1 alone increased (P<0.05) IGF1-induced E2 production. FB1 in combination with \ufffdZEA decreased (P < 0.05) E2 production. FB1 at 1, 1.5 and 3 \ufffdM slightly inhibited (P < 0.05) E2 production. BEA at concentrations \ufffd 3 \ufffdM was found to strongly decrease (P < 0.05) both steroid production and FB1 did not influence the effects of BEA. At 10 \ufffdM both mycotoxins decreased (P < 0.001) serum-induced GC proliferation. At 30 \ufffdM, BEA showed inhibitory effects on FSH plus IGF-1-induced CYP11A1 and CYP19A1 mRNA abundance (P < 0.05), whereas FB1 at 30 \ufffdM had no effect on CYP11A1 and CYP19A1 gene expression. As regards the effects of FB1 and BEA, alone and combined, on the Caco-2 intestinal barrier model data showed a TEER decrease after 1 h and 2 h of Bl exposure to BEA at 0.5 and 1.5 \ufffdM and after 24 h of Bl exposure to BEA at 0.5 \ufffdM, whereas after 24 h of Bl exposure, BEA at 3 and 6 \ufffdM was found to significantly (P < 0.05) increase TEER. FB1 had no effect on the intestinal barrier integrity and when combined with BEA the TEER increase induced by BEA was no longer observed. Cytokine release was observed only after exposure to BEA alone, and not in combination with FB1, with an increase of IL-6 and IL8 release after apical exposure to 3 and 6 \ufffdM and after basolateral exposure to 1.5, 3, 6 \ufffdM for IL-6 and only to 6 \ufffdM for IL-8. TNF- \ufffd release was induced by Ap (0.5 -1.5 \ufffdM) and Bl (1.5 \ufffdM) exposure to BEA. Overall, these results provide information on in vitro toxicological effects of Fusarium mycotoxins

    Prevalence of intestinal protozoa infection among school-aged children on Pemba Island, Tanzania, and effect of single-dose albendazole, nitazoxanide and albendazole-nitazoxanide.

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    Pathogenic intestinal protozoa infections are common in school-aged children in the developing world and they are frequently associated with malabsorption syndromes and gastrointestinal morbidity. Since diagnosis of these parasites is difficult, prevalence data on intestinal protozoa is scarce. We collected two stool samples from school-aged children on Pemba Island, Tanzania, as part of a randomized controlled trial before and 3 weeks after treatment with (i) single-dose albendazole (400 mg); (ii) single-dose nitazoxanide (1,000 mg); (iii) nitazoxanide-albendazole combination (1,000 mg--400 mg), with each drug given separately on two consecutive days; and (iv) placebo. Formalin-fixed stool samples were examined for the presence of intestinal protozoa using an ether-concentration method to determine the prevalence and estimate cure rates (CRs). Almost half (48.7%) of the children were diagnosed with at least one of the (potentially) pathogenic protozoa Giardia intestinalis, Entamoeba histolytica/E. dispar and Blastocystis hominis. Observed CRs were high for all treatment arms, including placebo. Nitazoxanide showed a significant effect compared to placebo against the non-pathogenic protozoon Entamoeba coli. Intestinal protozoa infections might be of substantial health relevance even in settings where they are not considered as a health problem. Examination of a single stool sample with the ether-concentration method lacks sensitivity for the diagnosis of intestinal protozoa, and hence, care is indicated when interpreting prevalence estimates and treatment effects

    Systematic review of studies generating individual participant data on the efficacy of drugs for treating soil-transmitted helminthiases and the case for data-sharing

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    Preventive chemotherapy and transmission control (PCT) by mass drug administration is the cornerstone of the World Health Organization (WHO)’s policy to control soil-transmitted helminthiases (STHs) caused by Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm) and hookworm species (Necator americanus and Ancylostama duodenale) which affect over 1 billion people globally. Despite consensus that drug efficacies should be monitored for signs of decline that could jeopardise the effectiveness of PCT, systematic monitoring and evaluation is seldom implemented. Drug trials mostly report aggregate efficacies in groups of participants, but heterogeneities in design complicate classical meta-analyses of these data. Individual participant data (IPD) permit more detailed analysis of drug efficacies, offering increased sensitivity to identify atypical responses potentially caused by emerging drug resistance

    Study and implementation of urogenital schistosomiasis elimination in Zanzibar (Unguja and Pemba islands) using an integrated multidisciplinary approach

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    ABSTRACT: BACKGROUND: Schistosomiasis is a parasitic infection that continues to be a major public health problem in many developing countries being responsible for an estimated burden of at least 1.4 million disability-adjusted life years (DALYs) in Africa alone. However, morbidity due to schistosomiasis has been greatly reduced in some parts of the world, including Zanzibar. The Zanzibar government is now committed to eliminate urogenital schistosomiasis. Over the next 3--5 years, the whole at-risk population will be administered praziquantel (40 mg/kg) biannually. Additionally, snail control and behaviour change interventions will be implemented in selected communities and the impact measured in a randomized intervention trial. METHODS: In this 5-year research study, on both Unguja and Pemba islands, urogenital schistosomiasis will be assessed in 45 communities with urine filtration and reagent strips in 4,500 schoolchildren aged 9--12 years annually, and in 4,500 first-year schoolchildren and 2,250 adults in years 1 and 5. Additionally, from first-year schoolchildren, a finger-prick blood sample will be collected and examined for Schistosoma haematobium infection biomarkers. Changes in prevalence and infection intensity will be assessed annually. Among the 45 communities, 15 were randomized for biannual snail control with niclosamide, in concordance with preventive chemotherapy campaigns. The reduction of Bulinus globosus snail populations and S. haematobium-infected snails will be investigated. In 15 other communities, interventions triggering behaviour change have been designed and will be implemented in collaboration with the community. A change in knowledge, attitudes and practices will be assessed annually through focus group discussions and in-depth interviews with schoolchildren, teachers, parents and community leaders. In all 45 communities, changes in the health system, water and sanitation infrastructure will be annually tracked by standardized questionnaire-interviews with community leaders. Additional issues potentially impacting on study outcomes and all incurring costs will be monitored and recorded. DISCUSSION: Elimination of schistosomiasis has become a priority on the agenda of the Zanzibar government and the international community. Our study will contribute to identifying what, in addition to preventive chemotherapy, needs to be done to prevent, control, and ultimately eliminate schistosomiasis, and to draw lessons for current and future schistosomiasis elimination programmes in Africa and elsewhere.Trial registrationISRCTN4883768

    Low Dose Daily Iron Supplementation Improves Iron Status and Appetite but not Anemia, Whereas Quarterly Anthelminthic Treatment Improves Growth, Appetite and Anemia in Zanzibari Preschool Children.

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    Iron deficiency and helminth infections are two common conditions of children in developing countries. The consequences of helminth infection in young children are not well described, and the efficacy of low dose iron supplementation is not well documented in malaria-endemic settings. A 12-mo randomized, placebo controlled, double-blind trial of 10 mg daily iron and/or mebendazole (500 mg) every 3 mo was conducted in a community-based sample of 459 Zanzibari children age 6-71 mo with hemoglobin > 70 g/L at baseline. The trial was designed to examine treatment effects on growth, anemia and appetite in two age subgroups. Iron did not affect growth retardation, hemoglobin concentration or mild or moderate anemia (hemoglobin < 110 g/L or < 90 g/L, respectively), but iron significantly improved serum ferritin and erythrocyte protoporphyrin. Mebendazole significantly reduced wasting malnutrition. but only in children <30 mo old. The adjusted odds ratios (AORs) for mebendazole in this age group were 0.38 (95% CI: 0.16, 0.90) for weight-for-height less than -1 Z-score and 0.29 (0.09, 0.91) for small arm circumference. In children <24 mo old, mebendazole also reduced moderate anemia (AOR: 0.41, 0.18, 0.94). Both iron and mebendazole improved children's appetite, according to mothers' report. In this study, iron's effect on anemia was limited, likely constrained by infection, inflammation and perhaps other nutrient deficiencies. Mebendazole treatment caused unexpected and significant reductions in wasting malnutrition and anemia in very young children with light infections. We hypothesize that incident helminth infections may stimulate inflammatory immune responses in young children, with deleterious effects on protein metabolism and erythropoiesis

    Egg excretion indicators for the measurement of soil-transmitted helminth response to treatment

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    BACKGROUND: Periodic administration of anthelmintic drugs is a cost-effective intervention for morbidity control of soil-transmitted helminth (STH) infections. However, with programs expanding, drug pressure potentially selecting for drug-resistant parasites increases. While monitoring anthelmintic drug efficacy is crucial to inform country control program strategies, different factors must be taken into consideration that influence drug efficacy and make it difficult to standardize treatment outcome measures. We aimed to identify suitable approaches to assess and compare the efficacy of different anthelmintic treatments. METHODOLOGY: We built an individual participant-level database from 11 randomized controlled trials and two observational studies in which subjects received single-agent or combination therapy, or placebo. Eggs per gram of stool were calculated from egg counts at baseline and post-treatment. Egg reduction rates (ERR; based on mean group egg counts) and individual-patient ERR (iERR) were utilized to express drug efficacy and analyzed after log-transformation with a linear mixed effect model. The analyses were separated by follow-up duration (14-21 and 22-45 days) after drug administration. PRINCIPAL FINDINGS: The 13 studies enrolled 5,759 STH stool-positive individuals; 5,688 received active medication or placebo contributing a total of 11,103 STH infections (65% had two or three concurrent infections), of whom 3,904 (8,503 infections) and 1,784 (2,550 infections) had efficacy assessed at 14-21 days and 22-45 days post-treatment, respectively. Neither the number of helminth co-infections nor duration of follow-up affected ERR for any helminth species. The number of participants treated with single-dose albendazole was 689 (18%), with single-dose mebendazole 658 (17%), and with albendazole-based co-administrations 775 (23%). The overall mean ERR assessed by day 14-21 for albendazole and mebendazole was 94.5% and 87.4%, respectively on Ascaris lumbricoides, 86.8% and 40.8% on hookworm, and 44.9% and 23.8% on Trichuris trichiura. The World Health Organization (WHO) recommended criteria for efficacy were met in 50%, 62%, and 33% studies of albendazole for A. lumbricoides, T. trichiura, and hookworm, respectively and 25% of mebendazole studies. iERR analyses showed similar results, with cure achieved in 92% of A. lumbricoides-infected subjects treated with albendazole and 93% with mebendazole; corresponding figures for hookworm were 70% and 17%, and for T. trichiura 22% and 20%. CONCLUSIONS/SIGNIFICANCE: Combining the traditional efficacy assessment using group averages with individual responses provides a more complete picture of how anthelmintic treatments perform. Most treatments analyzed fail to meet the WHO minimal criteria for efficacy based on group means. Drug combinations (i.e., albendazole-ivermectin and albendazole-oxantel pamoate) are promising treatments for STH infections

    The focal attention window size explains letter substitution errors in reading

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    Acquired Neglect Dyslexia is often associated with right-hemisphere brain damage and is mainly characterized by omissions and substitutions in reading single words. Martelli et al. proposed in 2011 that these two types of error are due to different mechanisms. Omissions should depend on neglect plus an oculomotor deficit, whilst substitutions on the difficulty with which the letters are perceptually segregated from each other (i.e., crowding phenomenon). In this study, we hypothesized that a deficit of focal attention could determine a pathological crowding effect, leading to imprecise letter identification and consequently substitution errors. In Experiment 1, three brain-damaged patients, suffering from peripheral dyslexia, mainly characterized by substitutions, underwent an assessment of error distribution in reading pseudowords and a T detection task as a function of cue size and timing, in order to measure focal attention. Each patient, when compared to a control group, showed a deficit in adjusting the attentional focus. In Experiment 2, a group of 17 right-brain-damaged patients were asked to perform the focal attention task and to read single words and pseudowords as a function of inter-letter spacing. The results allowed us to confirm a more general association between substitution-type reading errors and the performance in the focal attention task
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