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

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

In Vitro toxicological effects of Fumonisin B1 and Beauvericin on bovine granulosa cells

Fumonisin B1 (FB1) and beauvericin (BEA) are fusariotoxins found to co-exist in food and feed commodities. The aim of this study is to evaluate the individual and combined effects of FB1 and BEA on bovine granulosa cell proliferation and steroid production. Granulosa cells (GC) from small bovine follicles (1-5 mm) were cultured for 48 hours in 10% fetal bovine serum followed by 48 hours in a serum-free medium containing 500 ng/ml of testosterone (as an estradiol precursor), 30 ng/ml of FSH and 30 ng/ml of IGF-I with and without FB1 (3 µM) and BEA (3 µM). At the end of the experiment, the numbers of GC were determined using a Coulter counter (Beckman Coulter, USA) and concentrations of progesterone and estradiol in the culture medium were determined by radioimmunoassay. FB1 and BEA, both individually and in combination, showed an inhibitory effect (P < 0.05) on GC proliferation. The number of GC decreased by 17.7%, 54.2% and 61.0% after exposure to FB1 (3 µM), BEA (3 µM) and FB1 (3 µM) plus BEA (3 µM) respectively. FB1 (3 µM) had no effect (P > 0.05) on estradiol and progesterone production, whereas BEA (3 µM), both alone and in combination with FB1 (3 µM), was found to decrease (P < 0.001) the production of both steroids drastically. In conclusion, this in vitro study indicates that FB1 and BEA, both individually and in combination, may affect GC proliferation to different extents and shows the drastic inhibitory effects of BEA on steroid production

Mini-FLOTAC, an Innovative Direct Diagnostic Technique for Intestinal Parasitic Infections: Experience from the Field.

Soil-transmitted helminths and intestinal protozoa infection are widespread in developing countries, yet an accurate diagnosis is rarely performed. The aim of this study was to evaluate the recently developed mini-FLOTAC method and to compare with currently more widely used techniques for the diagnosis of intestinal parasitic infections in different settings. The study was carried out in Dharamsala, Himachal Pradesh, India, and in Bukumbi, Tanzania. A total of 180 pupils from two primary schools had their stool analyzed (n = 80 in Dharamsala and n = 100 in Bukumbi) for intestinal parasitic infections with three diagnostic methods: direct fecal smear, formol-ether concentration method (FECM) and mini-FLOTAC. Overall, 72% of the pupils were positive for any intestinal parasitic infection, 24% carried dual infections and 11% three infections or more. The most frequently encountered intestinal parasites were Entamoeba coli, Entamoeba histolytica/dispar, Giardia intestinalis, hookworm, (and Schistosoma mansoni, in Tanzania). Statistically significant differences were found in the detection of parasitic infections among the three methods: mini-FLOTAC was the most sensitive method for helminth infections (90% mini-FLOTAC, 60% FECM, and 30% direct fecal smear), whereas FECM was most sensitive for intestinal protozoa infections (88% FECM, 70% direct fecal smear, and 68% mini-FLOTAC). We present the first experiences with the mini-FLOTAC for the diagnosis of intestinal helminths and protozoa. Our results suggest that it is a valid, sensitive and potentially low-cost alternative technique that could be used in resource-limited settings--particularly for helminth diagnosis

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

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

Diagnostic Accuracy of Five Serologic Tests for Strongyloides stercoralis Infection

Background:The diagnosis of Strongyloides stercoralis (S. stercoralis) infection is hampered by the suboptimal sensitivity of fecal-based tests. Serological methods are believed to be more sensitive, although assessing their accuracy is difficult because of the lack of sensitivity of a fecal-based reference ("gold") standard.Methods:The sensitivity and specificity of 5 serologic tests for S. stercoralis (in-house IFAT, NIE-ELISA and NIE-LIPS and the commercially available Bordier-ELISA and IVD-ELISA) were assessed on 399 cryopreserved serum samples. Accuracy was measured using fecal results as the primary reference standard, but also using a composite reference standard (based on a combination of tests).Results:According to the latter standard, the most sensitive test was IFAT, with 94.6% sensitivity (91.2-96.9), followed by IVD-ELISA (92.3%, 87.7-96.9). The most specific test was NIE-LIPS, with specificity 99.6% (98.9-100), followed by IVD-ELISA (97.4%, 95.5-99.3). NIE-LIPS did not cross-react with any of the specimens from subjects with other parasitic infections. NIE-LIPS and the two commercial ELISAs approach 100% specificity at a cut off level that maintains ≥70% sensitivity.Conclusions:NIE-LIPS is the most accurate serologic test for the diagnosis of S. stercoralis infection. IFAT and each of the ELISA tests are sufficiently accurate, above a given cut off, for diagnosis, prevalence studies and inclusion in clinical trials.Fil: Bisoffi, Zeno. Sacro Cuore Hospital; ItaliaFil: Buonfrate, Dora. Sacro Cuore Hospital; ItaliaFil: Sequi, Marco. Istituto Di Ricerche Farmacologiche Mario Negri; ItaliaFil: Mejia, Rojelio. National Institute Of Allergy And Infectious Diseases; Estados UnidosFil: Cimino, Rubén Oscar. Universidad Nacional de Salta. Sede Regional Orán. Instituto de Investigación de Enfermedades Tropicales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Krolewiecki, Alejandro Javier. Universidad Nacional de Salta. Sede Regional Orán. Instituto de Investigación de Enfermedades Tropicales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Albonico, Marco. Sacro Cuore Hospital; ItaliaFil: Gobbo, Maria. Sacro Cuore Hospital; ItaliaFil: Bonafini, Stefania. Sacro Cuore Hospital; ItaliaFil: Angheben, Andrea. Sacro Cuore Hospital; ItaliaFil: Requena-Mendez, Ana. Universidad de Barcelona; EspañaFil: Muñoz, José. Universidad de Barcelona; EspañaFil: Nutman, Thomas B.. National Institute Of Allergy And Infectious Diseases; Estados Unido

Controlling Soil-Transmitted Helminthiasis in Pre-School-Age Children through Preventive Chemotherapy

Pre-school age children account for 10%–20% of the 2 billion people worldwide who are infected with soil-transmitted helminths (STHs): Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm), and Ancylostoma duodenale/Necator americanus (hookworms). Through a systematic review of the published literature and using information collated at World Health Organization headquarters, this paper summarizes the available evidence to support the recommendation that pre-school children should be included in regular deworming programmes. The first section describes the burden of STH disease in this age group, followed by a summary of how infection impacts iron status, growth, vitamin A status, and cognitive development and how STHs may exacerbate other high mortality infections. The second section explores the safety of the drugs themselves, given alone or co-administered, drug efficacy, and the importance of safe administration. The third section provides country-based evidence to demonstrate improved health outcomes after STH treatment. The final section provides country experiences in scaling up coverage of pre-school children by using other large scale public health interventions, including vitamin A programmes, immunization campaigns, and Child Health days. The paper concludes with a number of open research questions and a summary of some of the operational challenges that still need to be addressed

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.

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

Efficacy and Safety of Nitazoxanide, Albendazole, and Nitazoxanide-Albendazole against Trichuris trichiura Infection: A Randomized Controlled Trial

More than 5 billion people are at risk of infection with one of the three most common intestinal worms, the roundworm Ascaris lumbricoides, the whipworm Trichuris trichiura, and two different kinds of hookworms. The global strategy to control these intestinal worm infections is through the regular administration of deworming drugs to school-aged children (albendazole, 400 mg; mebendazole, 500 mg). However, especially against T. trichiura, a low treatment response is observed with single doses of both drugs. We tested the antiprotozoal drug nitazoxanide, which had shown promising trichuricidal properties in in vitro experiments. A randomized controlled trial was carried out on the island of Pemba in Tanzania. Four treatment arms were included: (i) single albendazole (400 mg), (ii) single 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. Children were asked for adverse events at several time points after treatment. Nitazoxanide showed no ability to cure T. trichiura-infected children and caused significantly more mild adverse events than placebo. Albendazole and the nitazoxanide-albendazole combination showed only a minimal effect against T. trichiura. Our results emphasize the urgent need to develop new, safe, and effective anthelmintic drugs against T. trichiura

Assessment of anthelmintic efficacy of mebendazole in school children in six countries where soil-transmitted helminths are endemic

BACKGROUND: Robust reference values for fecal egg count reduction (FECR) rates of the most widely used anthelmintic drugs in preventive chemotherapy (PC) programs for controlling soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, and hookworm) are still lacking. However, they are urgently needed to ensure detection of reduced efficacies that are predicted to occur due to growing drug pressure. Here, using a standardized methodology, we assessed the FECR rate of a single oral dose of mebendazole (MEB; 500 mg) against STHs in six trials in school children in different locations around the world. Our results are compared with those previously obtained for similarly conducted trials of a single oral dose of albendazole (ALB; 400 mg). METHODOLOGY: The efficacy of MEB, as assessed by FECR, was determined in six trials involving 5,830 school children in Brazil, Cambodia, Cameroon, Ethiopia, United Republic of Tanzania, and Vietnam. The efficacy of MEB was compared to that of ALB as previously assessed in 8,841 school children in India and all the above-mentioned study sites, using identical methodologies. PRINCIPAL FINDINGS: The estimated FECR rate [95% confidence interval] of MEB was highest for A. lumbricoides (97.6% [95.8; 99.5]), followed by hookworm (79.6% [71.0; 88.3]). For T. trichiura, the estimated FECR rate was 63.1% [51.6; 74.6]. Compared to MEB, ALB was significantly more efficacious against hookworm (96.2% [91.1; 100], p CONCLUSIONS/SIGNIFICANCE: A minimum FECR rate of 95% for A. lumbricoides, 70% for hookworm, and 50% for T. trichiura is expected in MEB-dependent PC programs. Lower FECR results may indicate the development of potential drug resistance